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SMITHSONIAN 1 FR fe fr Zz = = , 4 «th YY ee = Zz wd # es tof fs see ed Sk =) . =) SAS = = 2 WWE 2 E “3 : 2 WWE z = WY = b : 5 = WY 2 Bi. Wee el ) 2 o Zz aoe = SIV LIBRARIES SMITHSONIAN INSTITUTION NOLLMLILSNI_ NVINOSHLIWS S3IYVUGIT_ LIBRARIES SMITHSONIAN I < = OU = = 2 S 7 VOILNLILSNI_NVINOSHLINS S3IYVYGIT LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NYINOSHLINS. S ’ Te Zz Re ut eg ee Pua 2a n ae = ————_ ” —— > me ” shee si ~ f WILLIAM H. DALE ew i | f SECTIONAL LIBRARY | ei DIVISION OF MOLLUSKS VELIGER A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, Berkeley, California Volume 12 July 1, 1969 to April 1, 1970 Page II THE VELIGER Foreword to Volume 12 IT HAS BEEN SAID that everybody talks about the weather but nobody does anything about it. The same thing could be said about inflation. We are all painfully aware of its consequences. Yet, we at the Veliger think that we are doing our share — and perhaps a little more. In spite of the continually rising cost of paper, printing and postage, over the years we have effectively lowered our prices. Our first volume could be obtained at that time for $1.-; it comprised 40 pages and had no illus- trations. The present volume was sent to our members for their dues of $8.- — a rise in cost of 800%; but the volume comprises 488 pages and 64 plates, 5 of them in color — an increase in page numbers alone of over 1200% with the added bonus of the many fine plates. When the dues and subscription rates for the coming year were set, very careful consideration was given to the present inflationary trends. But despite these pressures, the decision was made to keep the dues and subscription rates at their present low level. This was done not without the hope that our members and subscribers would assist us in our effort by helping to increase the number of members and subscribers. We feel that no one need hesitate to recommend the journal to his conchological and malacological friends. It also will assist us to keep our overhead expenses at a minimum if members will pay their dues promptly as well as advise us in proper time of address changes, thereby making all our financial resources available for our primary goal — the continued pro- duction of our journal. That it has been possible to continue producing our journal under the ever more stringent financial conditions has been due mainly to the selfless devotion of a very few individuals. Though they wish to remain unnamed, your editor would be remiss if he were not expressing his deep appreciation to each and every one of them. Sincerely, Your Editor Vol. 12; No. 4 Vol. 12; No. 4 TABLE OF CONTENTS A bibliography of the biological writings of PHP PEARSALL CARPENTER. BISGEINIEMV- | COAN) | i seee eeh ns ferret tne esc 222 Additional bathymetric and locality data for some opis- thobranchs and an octopus from Santa Barbara County, California. RICHARD S. LEE & PATRICK BROPHY esses 220 A list of recommended nomenclatural changes for Mac- FaRLAND’s “Studies of opisthobranchiate mollusks of the Pacific coast of North America.” RIGETARDWATIROUT ER: enna ve dol ee. 371 A mechanical shell washer. JacgueELin N. MILver & Cart L. HUBBS wee 379 An annotated bibliography of references to marine Mol- lusca from the northern state of Sonora, Mexico. CS AROMISKOGL UND etd ent can ele cece 427 Anatomical notes on the mactrid bivalve, Raeta plicatella Lamarck, 1818, with a review of the genus Raeta and related genera. Harotp W. Harry An ecological study of valley-forest gastropods in a mixed mesophytic situation of northern Kentucky. BraNnLey A. BRANSON & Donan L. BatcH_............ 333 A new species of gastropod (Fissurellidae, Fissurisepta) from the eastern North Pacific Ocean. LASS JM UGHLE, CLONZSceceeee e e 24 A new species of Helminthoglypta from the Mojave Desert. WAT TER DB SIVIEE DER titer ochre aia cs Bh 275 A new species of Muricopsis from West Mexico. GerorceE E. Rapwin & ANTHONY D’ArrItio ............. 351 A note on the chromosome number and interrelationships in the marine gastropod genus Thais of the United States Pacific Coast. MuzamMMiL AHMED & ALBERT K. SPARKS ( oeeccccson 293 A note on the opisthobranchs of Santa Cruz Island, Cali- fornia. STEVEN MSONG ti) chb ne ie Sanit SU Oe Od seat rah ets 232 A possible “defense” response in a commensal polychaete. Ronatp V. Dimock & Joyce G. DimocKk_ ...........0... A report on the feeding of Dendronotus iris on the antho- zoan Cerianthus sp. from Monterey Bay, California. Done RAWOBBERG pate ee eet Ae 383 A revision of the eastern Pacific Ovulidae. @RAWEORDRING CATE Hee ee een ee ee ee 95 Ascophyllum nodosum: a source of exotic invertebrates introduced into west coast near-shore marine waters. RICHARD MU MIBEER 2 eet ee AE 230 A simplified vacuum apparatus for collecting small nudi- branchs. ER OEIER MAN BUEAIGNEY 0 cscs ond wate. Memeo eee 142 THE VELIGER Page III A supplement to the annotated list of opisthobranchs from San Luis Obispo County, California. IRIGEARD/ AW ROLLER eerie tens neat mse eetenat 482 A three-dimensional representation of measurement data. PAu CHANLEY & W. A. VAN ENGEL sscsecensenens 78 Cadlina modesta: a range extension, with notes on habi- tat and a color variation. IANS s BERTS GH) Sige aortee ae anni neg eterna 231 Cargoa cupella, new genus and new species of nudibranch from Chesapeake Bay and the generic status of Okenia Menke, Idalia LrucKart, and Idalla ORSTED. RosAauie M. Vocet & LEONARD P. SCHULTZ... 388 Concerning the validity of the new species of Paravitrea proposed by BRANSON & Batcu (1970). Lanpon T: Ross & LAWRENCE C. ABELE oases 484 Correlation of radula tooth structure and food habits of three vermivorous species of Conus. JAMES NYBAKKEN sien eGt seme ontd ooh ose 316 Current paleontological investigations on Cenozoic marine mollusks of the west coast of North America. WarreN O. ADDICOTT & SABURO KANNO © erettsnsssessscsee 135 Cuttlebones on the beach at Galveston. Harowip W. Harry & SELMA FE SNIDER oivssscscsssssnn 89 Cyclostrema miranda BARTSCH, a synonym of Tornus sub- carinatus (MonTacuU). DONALD ERG: MOORE hye een rs See ar een ee 169 Cypraeidae of the Red Sea at Massawa, Ethiopia, with a zoogeographical analysis based on the ScHILDERs’ regional lists. MiCSonve Le. P RUEBUSH MR a ss inet. cautndad 201 Descriptions of a new genus and eight new species of eastern Pacific Fissurellidae, with notes on other spe- cles. JAMES DEOMGICEAN, «occ .cccetacatarian. tani lech eens 362 Escape response of the sea-anemone Anthopleura nigres- cens (VERRILL) to its predatory eolid nudibranch Herviella BABA spec. nov. RU SIROSIN Mra Sees oe tear a2, ores 74 Escape responses of three Indian molluscs. ANID VANSELT, 60 cl 0 aed ate es al ee 157 Five new species of Terebra from the eastern Pacific. Mwita BratcHer & R. D. BURGH tite ident 295 Identification of the feeding types in the genus Conus LINNAEUS. (CUE BIGING ee ae esate ean ae oe ae 160 Levels of spontaneous electrical and acetylcholinesterase activities during aestivation of the Indian apple snail, Pila globosa. P Muraut Mowan & P. Murari KrisHna Dass 37 Macoma (Psammacoma) pulleyi, a new clam from Louisi- ana. PAUL Ss BOVER ojo siocssccsntsicrsst cn cned ees nee eh ee 40 Page IV Malacological applications of scanning electron micro- scopy. I. Introduction and shell surface features. FAA s SOLE Ms scscentaastsnsriiclassncean aie ae ere een 394 Marine fouling and boring organisms in Monterey Harbor — II. Second year of investigation. Ee CHApERTIE ries Oe. See ee eae 182 Mimicry of the gastropod Mitrella carinata by the am- phipod Pleustes platypa. JUrESEM@ CRANE: fre SS ae Se ee ee 200 New range for Mopalia hindsi recurvans BARNAWELL, 1960. GLENN BurRGHARDT & LAURA BURGHARDT oe 229 New species of Panamic marine gastropods. (AMESMETS Melia Nese ese eee eee 310 Notes on the deep water calliostomas of the Panamic pro- vince, with descriptions of six new species. AMES EL MCLEAN: ate ee eee 421 Notes on the egg capsules and larval development of Conus purpurascens BRODERIP. PANES WINVBAKIKE Nis, 2208 Dees Binh paar eB ee 480 Notes on the Mitridae of the Eastern Pacific II — The genus Thala, with the description of a new species. GALE Gr SPHONI ga, bike at oe neha 2 eae We 84 Notes on the collection of Tritonia festiva (STEARNS, 1873) from the seas of Japan (Gastropoda: Nudibranchia). KIKUTARO BABA. ci dea, ee eee ee 132 Observations on the anatomy and biology of two Califor- nia vermetid gastropods. MIGHAET| Gi HAD ETER D2 etieetee eis ora een 301 Observations on the reproductive biology of the Kellet’s whelk, Kelletia kelleti. RIGHARD!]; ROSENTHAL 3 S22 S00) ee eee 319 Observations on the tentacles of Vaginulus borellianus Co tosl. ARISTEO)/RENZONTO encode oe eee 176 Occurrence of a rare squid, Chaunoteuthis mollis APPELL- 6F (family Onychoteuthidae) in the Indian Ocean. KN ANESIS( 3th ein ne eee 290 Occurrence of the sacoglossan opisthobranch Hermaea dendritica ALDER & HANcock in New England. Kerry B. CLarK & DAVID R. FRANZ oresmsssssnseseinaneen 174 On Pseudopythina rugifera (CARPENTER, 1864). WaLter NarcHioiet ha aioe eee ee 43 Observations on Pervicacia tristis (DEsHayES, 1859) and a comparison with other toxoglossan gastropods. WRB RUD MIAN ups hie ce oot ea a 53 Occurrence of the cephalaspid Philine sinuata (Stmmp- SON ) in southern New England, with a discussion of the species. DROP RANZ {EK S GUAR, 1.2.00 200 INE iad Bhd 69 On CEerNoHorsky’s designation of a lectotype for Murex mancinella LINNAEUS. Haroip E. Vokes THE VELIGER Vol. 12; No. 4 Panamic sites and archaeological mollusks of Lower Cali- fornia. LAWRENCE HL. FELDMAN, cieccmcscecneismnsrennnneent 165 Pleistocene symbiosis: pinnotherid crabs in pelecypods from Cape Blanco, Oregon. Victor A. ZULLO & DUSTIN D. CHIVERS 0 oun 72 Population characteristics of Protothaca staminea (Con- RAD) from Mugu Lagoon, California. Rona_p R. ScomptT & JOHN E. WARME on 193 Range extension of Tjlodina fungina in the Gulf of California. James W. McBetu « R. David BOWLUS nese 229 Range extension of Tochuina tetraquetra (PAuas, 1788) to Hokkaido, North Japan (Gastropoda : Nudibranchia). KIKUTARO. BABA j jasgeincencithgien tee 134 Range extensions for Acanthodoris hudsoni MacFarLaANnD, 1905, and Onchidoris bilamellata (LinNaEus, 1767). Gary R. McDONALD: eiscioctiecenniene ee 375 Relative growth patterns of two west coast squid (Gona- tus fabricii and Gonatopsis borealis). Larry 'T. SPENGER) ses:ecdtectindinecs Ree eee 171 Remarks on the taxonomic placement of Purpurellus JoussEaumME, 1880, with the description of a new species. WILuIAM K. EMERSON & ANTHONY D’AttTitio —_—«:145 Report on some abnormal chitons from California and British Columbia. GLENN BurGHARDT & LAURA BURGHARDT ou... 228 Reproductive cycle of the coot clam, Mulinia lateralis (Say), in Long Island Sound. ANTHONY CALABRESE) sencscisncardarhes-ca eee 265 Russian contributions to malacology. KENNETH J. BOSS. 222 e2 A ae cane 226 Seasonal gonadal changes of adult oviparous oysters in Tomales Bay, California. Cart J. Bere, Jricu eee A 27 Spawning notes V. — Acanthina angelica I. OLpRoyp, 1918 and Acanthina lugubris (SowerRBy, 1821). FAY HENRY, WOLFSON Ges. eenen 375 Supplementary comments on deep water Volutidae from the South China Sea and South Africa. HARALD) A. [REHDER "vs. cecchidank destin be ee 415 Technique for extraction and mounting of gastropod rad- ulae. E GrorGe, Ey RADWIN( once diecsceinaseeeeenne ae 143 The cowrie species living at Guam. CRAWEORD! Ni (CATE Goce eee 120 The distribution and ecology of sub-littoral species of Macoma (Bivalvia) off Moresby Island and in Satel- lite Channel, near Victoria, British Columbia. R. M. Dunnit « D. V. Eis The eastern Pacific cowries. CRAWFORD. IN. (CATE: 22... cceeentes 28 ae eee, 103 Vol. 12; No. 4 The effect of wave impact on some aspects of the biology of sea mussels. Jap cu Ei EVARGER) Geet 2 mere case ojo wane Meant 401 The endodontoid land snail genera Pilsbrycharopa and Paryphantopsis. JUIN, SOOTY. Creat cee ch uc art Men ee ee 239 The systematics and some aspects of the ecology of the genus Dendronotus. GORDON VAHROBIDETARD: aca Sot fishaseselicctescnedssausimtne 433 The west American species of Murexiella (Gastropoda: Muricidae), including two new species. IBMT AEA SAVOKIES! | ccttrnthe termine niet niu tae 325 Three new species of muricacean gastropods from the eastern Pacific. WiiuaM K. Emerson & AntTHony D’Attitio 270 Two new Epitoniidae from the Galapagos Islands. DEVE NAPING YU S EUAN IE | cet actclaccct Oh Peart sgcncssscerisetessseesa 330 Two new species of deepwater bivalves from the Carib- bean Sea. EVAR OV DBE MeN OKE Sie ite Mustaine ed adh ean lie al oni 357 Two new species of Galapagan turrid gastropods. WILuIAM K. EMERSON & GeorGE E. Rapwiw_........ 149 Two new species of the genus Caldukia BuRN & MILLER, 1969 (Mollusca: Gastropoda: Opisthobranchia) from New Zealand waters. VET EVAR CMMNITE EER) ites ene oe le bi ua dha 279 Uptake of sea water into the fluid spaces of the proso- branch gastropod, Acmaea scutum. IT emE PAVE BBE Rage nite crc ns 0, Part ceetnsuels cel es 417 AUTHOR INDEX ABELE, LAWRENCE G. see Ross, LANDON T. & — AppicoTt, WARREN O. & SABURO KANNO AHMED, MuZAMMIL & ALBERT K. SPARKS J\SSIGHOH CI ANG) DS, ae IN ae oe Mec re ee Basa, K1KUTARO BErc, Cart J., Jr. IBERTS CHa EVANS) )cnnee nese BLEAKNEY, J. SHERMAN Boss, KENNETH J. Bow us, R. Davin see McBETH, JAMES W. & — BOYER PAU INS ethene Men ten oe a a eae 40 BRANSON, BranLey A. & Donatp L. BatcH_.......... 333 BRATCHER, TWILA & R. D. BURGE occcssssssssssnsussssssssntsns 295 Bropuy, Patrick see Ler, RicHarp S. & — Burcu, R. D. see BRaTcHER, TWILA & — BuRGHARDT, GLENN & LAURA BURGHARDT ........ 228, 229 BurGHARDT, LAuRA see BURGHARDT, GLENN & — (CATABRESE VAINDHONY 9) tees freon i ua ins Aad L 265 CATES GRAWFORDYNS; Shot. Se OoNLO3S a al20 THE VELIGER CHANLEY, PAUL & W.A. VAN ENGEL rcsmssssssmssssssnsasssseee 78 Curvers, Dustin D. see ZULLO, Victor A. & — CiarK, KERRY B. & DAVID R. FRANZ rvsssssssssssssssssneen 174 Crark, K. see FRANZ, D. R. & — (OLOVAING , VERO SSI VG ce eee cect reer peer renee crmreteecerats 222 Cowan, Ian McT__.............. 24 Crane, Jutes M., Jr. 200 Dass, P. Murat KrisHNna see Mouan, P. Murai & — D’Attitio, ANTHONY see EMERSON, WILLIAM K. & — see also: RapDwin, GrEorcE E. & — Dimock, Joyce G. see Dimock, Ronatp V. Dimock, RONALD V. & JOYCE G. DIMOCK oeeeecsesnsine 65 ID) einRpacses IS, IML CE LDS WE OVS) ert eromeemnpermeemrenoreremmee 207 DU SHANE, SELELEN set sisstafeoscicescsasissvasectisiatantictewnssssmtaanots 330 Exus, D. V. see DUNNILL, R. M. & — EMERSON, W. K. & A. D?ATTILIO oivcescsssussssssnsinnee 145, 270 EMERSON, WILLIAM K. & GEorGE E. RADWIN esmeese 149 IBELDMANRICAWREN CE sbi) ee eesreenne nn nnn ee see 165 omnes PaRUEBUSH eee eae 201 BRAN ZI Rese KCI CEARK), ; coer ni ee ee 69 Haverue, E. C. HaprFietp, MicHaet G. LARGER Je Rete ater em meres Nestea. es at CAE 401 PARRY TARO ED. Wi crises ies Ue ee Ee ae ea 1 Harry, HAROLD W. & SELMA E SNIDER oovssssssssessssssssnseeee 89 Husss, Cart L. see MILter, JAcQUELIN N. Kanno, SABuRO see ApDICOTT, WARREN O. & — LEE, RICHARD S. & PATRICK BROPHY ( osscssssssssssssussssns 220 1 GY o.Y Ge OD Date etre eet EONG SO TEVEN Po) |. ciseteteece teeta saree accra eareines McBetH, James W. & R. D. Bowtus McDona_p, Gary R............ IMGIERAIN SDJ AMES#EN: cha cnren meee canaane MILLER, JACQUELIN N. & Cart L. Husss Mier, MicHaet C............ Mitter, RicHarp L. ....... Miter, WALTER B. Mouan, P Murat & P. Murai KrisHNa Dass ..... 37 Moore, Donatp R. NARCHI, WALTER ..ececos 43 INESISHKESNe) cecsicesecnnsann 290 NYBAKKEN, JAMES Rapwin, GrorcE E. see also: EMERSON, WILLIAM K. & — 143 Rapwin, GrEorGE E. & ANTHONY D’ATTILIO ocecsecscs 351 IREHDERWEVARALD IA cossetiead deccssane ueccsne enn 415 IRENZONIGP ARIS TRON pester ee ie RoBILLIARD, GorDon A. IROLEER RICHARD) Ramer tele RosENTHAL, RicHarD J. Rosin, R. IRUDMANEA Wile es ee ie SEE ee ee een a 53 Page VI THE VELIGER RuesusuH, L. P. see Fon, T. C. & — SCHMDDT, RONALD R. & JOHN E. WARME eesti 193 ScHuLTz, Leonarp P. see RosALIE M. VocEL & — SKOGLUND,; CAROL 11h tea cee ee eee Meeeelinoneree 427 SNDDER, SELMA F see Harry, Harotp W. & — SOBEM: CALAN fk: cee tet a, 1) (enum elas 239, 394 SPHON, (GALEN Gi), 22 ee. eee eee ee ea 84 Sparks, ALBERT K. see AHMED, MUZAMMIL & — SPENCER CARRY Ay ee Cee 171 Van ENGEL, W. A. see CHANLEY, PAUL & — Vokes sEinaiiy He ten hee ccna ee 325 VoGcEL, Rosauiz M. & LEonarp P. SCHULTZ. .............. 388 VOKES; HAROLD) Bier Boa. eee ie ae 357, 368 WarME, JoHN E. see ScummpT, Ronatp R. & — WEBBER HEHE ih AUR er ee Oe a ene an 417 WoBBER}: Dony. RY hhh. ga a Oe 383 WOLFSON) PAY HENR Yarn ou eee wee ee 375 ZuLLO, Victor A. & DUSTIN D. CHIVERS (ovine Wi2 Vol. 12; No. 4 VELIGER THE A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, INC. Berkeley, California VOLUME 12 July 1, 1969 NUMBER I ConTENTS Anatomical Notes on the Mactrid Bivalve, Raeta plicatella Lamarck, 1818, with A Review of the Genus Raeta and Related Genera. (20 Text figures) Haro.p W. Harry A New Species of Gastropod (Bissrelndae: Rasurieniayy far the Basen North Pacific Ocean. (3 Text figures) Tan McT. Cowan Seasonal Gonadal Changes of Adult @uiesraue Gystersh in Glomale: Bay (Californie: (Plates 1 to 3; 1 Text figure) Cart J. Bere, Jr. Levels of Spontaneous Electrical and Aceurleholinestsrase INctivities durae Nestiva- tion of the Indian Apple Snail, Pila globosa. (1 Text vee P Murari Monan « P Murat Krisuna Dass Macoma (Psammacoma) pulleyi, a New Clam from Tous (2 Text eure) Paut S. Boyer On Pseudopythina ueiete (Canesten, 1864) (Bivalvia). Gl Text fegres) Water NarcHI Observations on Pervicacia tristis Gieerneee 1859) aaa a Gonpaneen cain oer Toxoglossan Gastropods. (5 Text figures) W. B. RupMAN 6 Aue en pniee ae Nana A Possible “Defense” Reeponseli ina s Commmencal Polychacte (Plate 4) Ronatp V. Dimock « Joyce G. Dimock Occurrence of the Cephalaspid Philine shed Greco it in Souler New enelandl with a Discussion of the Species. (8 Text figures) D. R. Franz « K. Ciark Pleistocene Symbiosis: Pinnotherid Gens in Weelenypods) fara cone Bianco! orear (Plate 5) Victor A. ZuLLo « Dustin D. CHIVERS [Continued on Inside Front Cover] 7 a ra pre ee Distributed free to Members of the California Malacozoological Society, Inc. Subscriptions (by Volume only) payable in advance to Calif: Malacozool. Soc., Inc. ( gut 24 1969 Volume 12: $18. Domestic; $19.- in the Americas; 19.50 in all other Foreign Countries Single copies this issue $12.-. Postage extra. Send subscription orders to Mrs. JEAN M. Carte, 12719 San Vicente Boulevard, Los Angeles, California 90049. Address all other correspondence to Dr. R. Stouer, Editor, Department of Zoology, University of California, Berkeley, California 94720 Second Class Postage paid at Berkeley, California R A R ES - ConTENTs — Continued Escape Response of the Sea-Anemone Anthopleura nigrescens (VERRILL) to its Predatory Eolid Nudibranch Herviella Baza spec. nov. Rev ROSINSS ee =), SESE! ee Heer amen Al A Three-Dimensional Resretentaron of ‘Measurement Data (4 Text figures) PauL CHANLEY & W. A. Van ENGEL ee ‘ dey Bent eer th nether 7S Notes on the Mitridae of the Eastern Pacific Ir - The Gann Thala, with the Description of a New Species. a 6; 2 Text ga I nee Gate G. SPHON. : : : a) Soa ee Od Cuttlebones on the Beach at Galveston! (3 Text figures) Haroitp W. Harry & SELMA FE SNIDER eee Suanaro aes!) A Revision of the Eastern Pacific Ovulidae. (Pate 7 to 10; et Maps) CrawForpD N. Cate. . . 2 het Es The Eastern Pacific Cowries. . eiates) It to 15; 3 Maps) Crawrorp N. Cate . . Sf cs ee sent epee EOS The Cowrie Species Living at Guan (Molluses : (Grsttopoday, (Plates 16 to 25; 1 Map) CRAwrForD NiiGATEs <7 iGer" otis Bee aia ote ee ey an ee nee a eT INKS) CZINDINIS) co 9 0 0 Baga wo kG See gaat Vora. of os. he IGA Notes on the Collection of Tritonia festiva iin 1873) from the Seas of Japan (Gastropoda : Nudibranchia) (1 Text figure) KIkuTARO BABA Range Extension of Tochuina tetraquetra (PaLias, 1788) to Hokkaido, North Japan (Gastropoda : Nudibranchia). KrxuTarO BABA Current Paleontologic Investigations on Cenozoic Marine Mollusks of the West Coast of North America. WarreN O. AppICoTT & SABURO KaNNO METHODS & TECHNIQUES... . aon ss(/1P) A Simplified Vacuum Apparatus for Collectine Ae Nae (1 Text figure) J. SHERMAN BLEAKNEY Technique for Extraction and Mounting of Gastropod Radulae. GrorcE E. RaDWIN Note: The various taxa above species are indicated by the use of different type styles as shown by the following examples, and by increasing indentation. ORDER, Suborder, DIVISION, Subdivision, SECTION, SUPERFAMILY, Famity, Subfamily, Genus, (Subgenus) New Taxa Vol. 12; No. 1 THE VELIGER Division Of Molluske sctionall Library Page | Anatomical Notes on the Mactrid Bivalve, Raeta plicatella LAMaRcK, 1818, with A Review of the Genus Raeta and Related Genera HAROLD W. HARRY Texas A&M Marine Laboratory, Galveston, Texas 77550 and Rice University, Houston, Texas 77001 (20 Text figures) TABLE OF CONTENTS Mina itech Ur Cte TD es secsesccesces ase ast ieeas vas saasteevsesdvasseesveatsvsesvsssesectontieosestee? I Part I. Raeta plicatella a. Ecology Ip e hia Vl on terete a setacceemterttortnrstntoneccommtionmneste ize 2 c. Anatomy d. Anatomical Discussion Part II. Systematics a. Genus Anatina b. Genus Raeia s. s. c. Subgenus Raetina __....... d. Subgenus Raetella _...... e. Systematic Discussion Weiteratune Cited) ee ee ede ans QI INTRODUCTION SEVENTY YEARS AGO, DALL (1898, p. 907) wrote of this species: “Notwithstanding the fact that dead valves of this shell are found in windrows on the beaches at some points of the south- ern coast, the character of the soft parts is unknown, and I shall be very greatly obliged to any one who can furnish me with a specimen of the animal in spirits in order that its systematic position may be positively settled.” Apparently nothing has yet been reported on its ana- tomy. It may, therefore, be worth recording notes which I made on a single intact live specimen, and fragments of two others, for this species has several unusual structural characters which heighten interest about its enigmatic ecology and systematic relationships. Raeta plicatella is the type of its genus. I have therefore included a review of this genus and related ones. Since nothing is known of the anatomies of any of the species of the other genera, conclusions on the systematics of this group must be based on characters of the shell. Descrip- tion of the shell of R. plicatella is deferred to the system- atic part of the paper. I am indebted to Mr. Pat Burke, Mr. Donald Harper, and Mr. Ronald Tomas for assistance in field work, and to the staff of the Mollusk Department of the United States National Museum for their generous hospitality while I studied the National Collection. PART I. Raeta plicatella (Lamarck, 1818) Ecology: Single, fresh valves are often abundant on the beaches along the Gulf of Mexico in Louisiana and Texas. Very rarely shells have a bored hole, probably made by Poli- nices duplicata Say, 1822. Joined valves of Raeta plica- tella are rare and live specimens even more so. I have found only two shells containing the flesh on the beach. Both were at the edge of the surf, and both had been picked open on the central part of the disk by sea gulls. Birds may account for the dearth of live specimens, even in the winter when rough surf often tosses up live snails and bivalves whose shells afford them more protection Page 2 (Anadara, Noctia, Dosinia, Tellina alternata Say, 1822, Busycon, Polinices and others). Raeta plicatella seems to be a species of the outer part of the surf zone, a region difficult to sample. The mollusks which live there are chiefly known by being cast up on the beach by rough surf, for they are not regularly found in the inner part of the surf zone frequented by swimmers, and several of them are not taken by dredging in waters seaward of this zone. At Galveston, the outer surf zone is only a few hundred yards wide, and from 2 to 3 fathoms depth. It is so close to shore that boats large enough for trawling and dredging cannot often be used there. In more than 60 dredged samples from 3 to 18 fathoms off Galveston, single, small juveniles of R. plica- tella occurred in two samples at 3 fathoms, and single fragments of larger shells were found in two samples of 5 fathoms. Not even identifiable pieces of shell occurred in any of the others. I had never seen shell fragments or juveniles of this species in the Galveston Bay complex, until the single intact specimen was found which furnished most of the anatomical data of this report. It was dredged from 2 fathoms, 14 October 1967, at the east end of the intra- coastal canal cutting Pelican Island, Lower Galveston Bay. Occasional live specimens of mollusks living in the outer surf zone are found in Galveston Bay. These are usually juveniles, or rarely small adults. Their scarcity and size suggest that their larvae have invaded this area, which is adjacent and connected by water to that in which they normally live, but that they are not able to complete their life cycle and establish perpetuating populations in the bays. Examples of such adventitious species found in the more saline parts of the bays, but with established populations only along the Gulf shore are Dosinia discus Reeve, 1850, Tellina alternata Say, 1822, Anadara brasili- ana, Periploma inequalis C.B.Apams, 1842, Noetia ponderosa Say, 1822, Pitar texasiana Dati, 1889, and Donax variabilis Say, 1822. Behavior: In the laboratory, the live specimen was lethargic. It did not move about in a dish of seawater, and the foot was not seen extended beyond the shell. The shell gaped slightly and continuously during the several days of ob- servation. The siphons were not withdrawn, even when the specimen was handled. Several colonies of the stalked ciliate protozoan, Car- chestum, were attached to the siphons near their tips, and also found on the periostracum between the margins of the valves along the postdorsal slope of the shell. A small colony of an encrusting bryozoan was on the THE VELIGER Vol. 12; No. 1 periostracum of the fused mantle margin near the pedal opening. The surface of the shell was clean and had no extraneous organisms. The presence of Carchesium and the bryozoan suggest this animal did not burrow, but was on its side on the substrate. This inference is further supported by the nature of the foot (see below). External Anatomy: The siphons (slightly contracted in Figure 1) are about 2 as long as the shell, and joined throughout their length. There is a slight groove between the two, on the sides. Figure i Diagram of the external anatomy of Raeta plicatella from a live, partly retracted specimen. The left valve and mantle have been removed. aa -—anterior adductor muscle _ap — anterior pedal retractor muscle f — foot g—gill Ip — labial palp pa-— posterior adductor po — pedal opening in mantle margin __ pr — posterior pedal retractor r—rectum sm-—siphonal membrane sp -—siphonal pocket wl-—right wall lamella of waste canal v— ventricle of heart The diameter of the excurrent siphon is about 4 that of the incurrent one. The opening of the excurrent siphon has a thin, transparent, conical flange extending from it, with a small opening at its tip. There are no papillae around the excurrent siphonal tip. The incurrent opening has no valve flange, but numerous short papillae are along its margin. Two papillae of this series, between the two siphonal openings, are larger than the rest. Every 10 minutes or so the siphons contracted rapidly, but only for a short distance, and the feces were expelled through the excurrent opening. A white, wavy seam on the top and bottom of the siphons evidently represents the junction of the two sides of the periostracum. This cuticular sheet extends to the Vol. 12; No. 1 THE VELIGER Page 3 tips of the siphons, lines the siphonal retraction cavity of the mantle, and all of the exposed mantle margin. It is very thin, and scarcely evident over the outer shell surface. The color of the living tissue was varied. There was no gross evidence of hemoglobin, the blood being colorless and the nerve ganglia white. The ovary was white, the liver the usual olive brown, the kidney was faint purplish brown. The labial palps and gills were faint orange yellow, and the foot was dingy white. The rest of the flesh was without notable color. The mantle is very thin, and colorless over the disk of the shell. The disk part is attached in small round spots, which are not the origin of muscle cells, but seem to be epithelial. The spots of attachment are 1 to 2mm in diameter, and widely scattered. The kidney extends into the lobes of the mantle, ex- tending downward well below the free margin of the gills (dashed line, Figure 2). This part of the mantle is thickened. The margins of the mantle lobes are fused to each other along the dorsal, anterior and ventral margins of the shell, and the attachment is thick and muscular. At the antero-ventral margin there is a small opening in the x Oy as SC pb Figure 2 Visceral mass and structures in the mantle at the hind end of the body. ap — anterior pedal retractor muscle ec — excurrent chamber of mantle cavity i-intestine hp-liver k-—kidney pb — posterior end of gills pg—pedal ganglion = pr—posterior pedal retractor muscle rms-— retractor muscles of siphons _ sc — style sac s—septum separating mantle chambers sm -—siphonal membrane sO—sense organ ssg — suspensory septum of gills st — stomach v-—ventricle of heart vg -— visceral ganglion cg — cerebral ganglion ga—gill axis ov — ovary marginal fusion, the pedal opening (Figure 1). This is surrounded on its inner margin by a thin, narrow velum, which may represent the inner mantle margin lamella. The latter is not evident as a distinct entity elsewhere. No “fourth pallial aperture”, below the siphonal pocket, was evident (see YoncE, 1948). At the hind angle of the shell, there is a large opening into the deep, blind siphonal pocket (Figure 1). | In front of the siphonal pocket, the siphonal retractor muscles form a flat, triangular mass in each mantle lobe, with the apex pointing forward. These muscles are small bundles, not forming a continuous sheet, but with spaces between them about half as wide as each bundle (Figure 2, rms). The origin of the siphonal retractor muscles is along the pallial sinus scar of the shell. They converge toward and extend into the siphons as longitudinal re- tractors. A thin, transparent diaphragm of mantle epithelium extends forward horizontally from between the inner openings of the siphons. This septum is a continuation of the diaphragm formed by the gill attachments, and with the latter it completely separates the incurrent and excur- rent chambers of the mantle cavity (Figure 2, s). There is a single lamella of mantle extending along both sides and the top of the incurrent siphonal opening, but not across its bottom (Figure 2, sm). This is the siphonal membrane (Kettoce, 1915). A pair of lamellae of moderate width extend forward from the ends of the siphonal membrane, one attached to each mantle lobe, to a point below the apex of the pallial sinus scar (Fig- ure 1, wl). These are the wall lamellae of the waste canal (KELLOocG, op. cit.). These three lamellae have intrinsic musculature, which on contraction decreases the height of the lamellae. They probably serve to guide pseudofeces into the incurrent siphon. The fused edge of the two mantle lobes ventrally is very thick (Figure 3), and filled chiefly with mantle margin muscles. Some of these pass from the position of the pallial line to the free, or exposed mantle margin, and thus pull the mantle margin upwards, away from the mar- gin of the shell. But the bulk of the muscles pass trans- versely, forming a mantle margin adductor muscle in this area, as in certain pholads, such as Cyrtopleura costata. There are a few strands of longitudinal muscles in this fused mass, particularly on the upper surface. The periostracum covering the free, ventral surface of the fused mantle margin has a white streak medially. Just above this streak are the two minute grooves (Figure 3, pg) in which the periostracum is formed, between what is homologous to the outer and middle mantle margin la- mellae of other bivalves, which do not have fused mantle lobes in this region. Page 4 The anterior adductor muscle (Figure 1, aa) is very elongate and narrow, extending along the anterior curve of the shell from the front end of the pedal opening to the front end of the hinge plate. It is merely a broadening of the mantle margin adductor muscle, and not a separate entity. The hind adductor muscle is reniform, and small for the size of the shell. Both muscles were opaque and white, with no gross evidence of “quick” and “catch” parts differentiated. WC wl Figure 3 Diagram of transverse section of ventral margin of Raeta plicatella, about one fourth the length from the hind end. m— mantle lobe rm — retractor muscle of mantle margin tm — transverse muscle of mantle margin wl — wall lamella Im — longitudinal muscle of mantle margin peg — periostracal groove sh — shell wc — waste canal The foot is atrophied to a small, elongated, wrinkled mass, flattened laterally and rounded at the free end. The free margin is acutely keeled, but without any groove. Probably the foot is never extended beyond the shell mar- gin in specimens of this size (44mm long). It is some- what muscular, the circular muscles extending only a little way up on the front margin of the visceral mass, but not up the hind margin of it. Anterior and posterior pedal retractor muscles each form a thin bundle along the front and hind margin, respectively, of the visceral mass (Figure 2, ap,pr). At their top, each muscle divides, the front one originating on the shell valves on each side and slightly above the mouth, and thus just above the anterior adductor muscle.. The hind pedal retractor has the rectum passing between its two short branches. THE VELIGER Vol. 12; No. 1 It originates on the shell valves just above the posterior adductor muscle scars. The visceral mass has an exceptionally thin wall, with little musculature. Probably this is a consequence of the atrophied foot. The covering is so thin that the internal organs of the visceral mass are easily seen through it. The gills have two demibranchs on each side. The ascending lamellae of all four demibranchs are attached to the mantle at about the level of the gill axes. The gill axes form almost a straight line running obliquely from a point a little way in front of the siphonal inner openings, forward and upward to a point just below and slightly in front of the umbos of the shell. The anterior halves of the attachment of the two gills are separated by the visceral mass, but behind it they are so joined that the excurrent chamber of the mantle cavity is completely separated from the incurrent one. Behind the visceral mass, the ascending lamellae of the medial demibranchs are attached to each other along their upper margins. The gill axes are here each suspended by a thin vertical septum, so that the excurrent chamber is divided into three compartments, two lateral and a medial, between the hind margin of the visceral mass and the lower end of the hind adductor muscle (Figure 2, ssg). Behind that point there is only a single tubular excurrent cham- ber, limited below by the horizontal septum of the mantle, laterally by the mantle proper, above by the lower surface of the kidney and the posterior adductor muscle, and behind the latter, an additional short horizontal septum of the mantle. The outer demibranchs are not as wide as the inner, and do not extend as far forward. They are semilunar in shape, with short filaments at both ends, increasing grad- ually and regularly in length to the middle of the demi- branch. The medial demibranchs extend a considerable distance forward, and actually begin well in front of the hind end of the attachment of the labial palps. The gills are eulamellibranchian, pleated, and all demibranchs have a groove along their free margin. The labial palps are large, subtriangular, with convex anterior margin, concave posterior margins, and rounded ventral angle (Figure 1). They are attached along a straight line to the visceral mass by their dorsal margin. The two free sides of this triangle have a narrow strip lacking the numerous vertical ridges which cover the opposing surfaces of the labial palps. These ridges extend almost to the mouth; the medial parts of the palps are narrow, with simple free margins. Only a few major features of the internal anatomy could be worked out. The two liver lobes, right and left, are rather small, and fill the periphery of the upper, ante- rior part of the visceral mass. The gonad, an ovary in the Vol. 12; No. 1 one complete specimen available, fills the posterior half of the visceral mass peripherally, pushing dorsally over the stomach and under the pericardium. The antero- ventral part of the visceral mass has a large coiled mass of intestine (Figure 2). The esophagus is short, opening into a large oval stomach. The interior of the stomach is much complicated with ridges and folds, details of which were not worked out. Most of the interior was covered by a loose lining of cuticular material, the gastric shield. A sorting area, of several oblique ridges on the left side, was not covered by the shield. Each liver lobe consists of a thin-walled, branched tube. The liver follicles, glandular in appearance, are not branched, but clustered about the tips of the smallest branches of the hepatic ducts. Each follicle is about 0.1 mm in diameter. Postero-ventrally, the stomach receives the style sac on the left, and the slightly smaller intestine opens beside it on the right. The style sac and intestine are completely separated, the former plunging down to the tip of the visceral mass and turning forward for a short distance, ending blindly. A well-formed crystalline style was pres- ent, after the clam had spent several days alive in the laboratory, and even after it had been opened for 2 days, maintained in the refrigerator at 4° C in sea water. The intestine is thin-walled, light brown, and evidently without musculature. A dark brown fecal rope was passed along by ciliary activity. The intestine is unusually long, about several times the length of the shell. It is mostly coiled in the lower front part of the visceral mass, in a part of the hemocoel free from liver and gonad. Two parts of the intestine are recognizable on the basis of size, position and internal structure. The first part (duo- denum) is imbedded in the ovary on the right of the style sac, and passes forward near the lower end of the visceral mass; it also forms the first few coils. It is about twice the diameter of the second part, the jejuno-ileal intestine. The latter makes up most of the coils, three of which loop symmetrically from side to side peripheral to the lower end of the liver; it then passes into the ovarian mass well ventrally, turns upward behind the style sac and enters the front end of the pericardium, beyond which point it may be called the rectum. After leaving the latter it passes between the two kidney lobes, over the outer sur- face of the posterior adductor muscle and opens into the hind part of the suprabranchial chamber of the mantle cavity, just in front of the excurrent siphon. I could not determine the relative lengths of the large and small intestine, nor their junction. Perhaps it is a gradual transition. The large (duodenal) intestine has a huge lamella, or typhlosole, in it, much thicker than the THE VELIGER Page 5 intestinal wall. At intervals of a few millimeters, this has short branches at right angles, but only along one side. These resemble buttresses. I could find no typhlosole in the small intestine, but perhaps one is present as a mere strip of cilia. Feces: The pseudofeces, consisting of particulate material as- sembled in the incurrent mantle cavity and rejected through the incurrent siphon, are poorly consoltdated ropes of sediment, slightly larger than a millimeter in diameter and a few centimeters long. True feces are of two types, which may be called ropes and pellets (Figure 4). The pellet type was seen in the Figure 4 Feces. Rope type on right, an unopened pellet left above, and a pellet cut transversely on left, below. rectum of the damaged specimens from the beach, and the rope type in the intestine of the intact specimen found in the bay. This specimen voided both types in the laboratory, and from that material Figure 4 was drawn. The rope type of feces evidently passes through the intestine with little rearranging of the materials involved. It consists of a single strand, 80 to 100mm long, with seg- ments of dark tan material alternating with segments of dark olive color. The lengths of the two segment types are not constant. Probably the olive colored material is derived from the liver, and the tan material is of undi- gested particles which entered the mouth. These were not Page 6 studied in detail. The packaged configuration of the rope, bent back upon itself several times as shown in Figure 4, probably occurs as the rope is defecated into the supra- branchial mantle chamber. This package has been passed from the animal, as had numerous pellets. The pellet feces were probably in the specimen when captured. They are constant in diameter, about 0.69 mm, and slightly variable in length, about 0.96 to 1.23mm long, with longer pellets being more abundant. Each pellet is elaborately constructed. The pellets are smooth, regular cylinders with abruptly truncated ends, one being slightly convex, the other slightly concave. The surface is uni- formly light tan colored, evidently of fine particles held compactly together with mucus. There is a single line, slightly incised, which begins in the middle of one end, makes about one complete turn on the lateral surface, and ends at the middle of the other end of the pellet. Breaking a pellet open gently reveals a central cavity which seems not to extend quite to the ends. Its diameter is about 4 that of the pellet, and.it is reniform in cross section. This cavity is loosely filled with granules of vary- ing sizes, all larger than those of the outer part. The outer part of the pellet has about five layers, probably of only one continuous sheet, wrapped around the central cavity. The innermost layer is wider and less firmly con- solidated than the others. The layers bend toward the concave side of the central cavity, and the spiral line on the outside seems to correspond to this also. At higher magnification, the particles of the outer shell of the pellet all seem to be inorganic, angular granules, rarely as large as 3u. No Brownian movement could be seen in a squash preparation in sea water, possibly be- cause the mucous matrix was too viscous. The granules of the central cavity are irregular spheres, from 10 to 14u in diameter. These are hyaline, golden brown and bright in reflected light. Also present were a few glassy angular flakes, colorless and polygonal, with sharp edges and angles. These are about 0.30 mm in maximum dimension. I was unable to find any organismal remains in the pellets, such as diatoms, even at 970 * magnification. The pericardium is a large, spacious, cuboidal sac located below the umbos (Figure 2). The ventricle of the heart surrounds the rectum, which transverses the peri- cardium lengthwise dorsally. The ventricle has two small projections antero-dorsally. The auricles are thin-walled triangular sacs diverted ventro-laterally. They nowhere touch each other. A light brown color on their exterior surface suggests a pericardial gland is present, but it does not extend onto the pericardial wall. There are two minute reno-pericardial openings on the post-ventral sur- face of the pericardial sac. THE VELIGER Vol. 12; No. 1 The kidney consists of two huge sacs, between the pericardium and the posterior adductor muscle. The pos- terior pedal retractor muscle passes between these sacs. Each sac is elongate, but bent upon itself, so that there is a dorsal moiety, beginning near the pericardium and passing backward to the adductor muscle, then turning forward ventrally to form the ventral moiety, which ends again at the pericardium. The large extensions of the kidneys into the mantle are projections from the upper moiety of each sac. The reno-pericardial passage is at the front end of the lower moiety of each sac, and a little farther back each lower moiety has a renopore opening into the excurrent mantle chamber, just in front of the post-pedal retractor muscle. The interiors of the kidney sacs are spacious; there are no trabeculae, but a smooth wall with large cilia, and numerous small holes opening into it (Figure 5). These are the ends of short narrow Figure 5 On the left, a part of the wall of the kidney, showing follicles extending from its outer surface and pores by which they open on the inside. Cells are shown in only one follicle. On the right, a single kidney cell from inside a kidney follicle. ducts of the kidney follicles. Each follicle is branched two or three times; they are thin-walled, transparent sacs (about 0.3mm diameter whose cavities are almost oc- cluded by the bulbous ends of the excretory cells. These cells are part of the follicular wall, but they extend in- ward by narrow, short stalks. The free end of each cell is spherical, having a large vacuole which holds a light golden fluid. The fluid does not seem to mix with sea water. Each vacuole also has a spherical mass of golden brown, opaque granules. The members of all three pairs of ganglia of the nervous system are fused, so that there are no commissures (Figure 2). The connectives between ganglionic pairs were not traced. The cerebral ganglia are just above the mouth. They are intermediate in size between the other Vol. 12; No. 1 two pairs. The pedal ganglia are 0.19mm long, and located at the front end of the base of the foot. The visceral ganglia are 0.3 mm long, and on the roof of the excurrent mantle chamber below the kidneys, but well in front of the posterior adductor muscle. There are two prominent sense organs on the mantle, one on each side of the upper part of the inner end of the incurrent siphon, just in front of the median accessory mantle fold. These may be osphradia. Each is connected by a large nerve to the visceral ganglion on its side. They are elongate oval masses, about 0.1 mm wide and 0.3 mm long, and as high as they are wide. The ovary of the intact specimen was a large, dendriti- cally branched multifolliculate organ, the follicles being slightly less than 0.1 mm diameter, containing thousands Figure 6 Tape worm larva from: cyst on intestine. Terminal sucker everted in complete specimen, retracted in the smaller figure. THE VELIGER Page 7 of eggs which appeared to be about ripe. The eggs are white, about 44, diameter, with a large germinal vesicle 27. diameter containing a nucleolus 13 diameter. There seems to be a single gonopore, opening into the front of the pericardial cavity just to the left of the rectum. If so, the eggs evidently must pass through the pericardium and kidney to reach the exterior. Parasite: A small cyst containing tapeworm larvae was attached to the outer surface of the intestine just below the stom- ach. It was white, and at first mistaken for a piece of the ovary. The cyst was thin-walled, elongate, with an irregu- lar surface. It contained several dozen larvae, each coiled to form a sphere. Released from the cyst into sea water, the larvae squirmed with peristaltic movement and everted the terminal sucker. They attached with the lateral suckers (bothridia) and moved along a glass surface by alternately attaching and releasing them. The larva (Figure 6) is fusiform, about 54y long. It is colorless, and the body is filled with small hyaline granules. The hind end tapers acutely, and the front end is rounded, with a deep, cup-shaped, muscular terminal sucker. This can be extended forward, or withdrawn to the level of the bothrydia. There are four elongate oval bothrydia, with small bases, attached symmetrically around the scolex. The cavity of each bothrydium is divided by two transverse partitions into three chambers (areolae) of equal size. No spines were seen at 100 x magnification, nor could any internal anatomical details be made out. Anatomical Discussion: Most notable features of the anatomy of Raeta plica- tella are the extension of the kidney into the mantle, the thin wall of the visceral mass, the atrophied foot, and the enormously long intestine. The abnormal ecological occurrence of the specimen on which most of this ana- tomical account is based might cast doubt upon some of the data on habits and anatomy. There is indeed an in- trinsic conflict between the two: the long siphons and atrophied foot suggest this is a deep burrower which does not move about much in later life. An atrophied foot in late life of bivalves is probably more common than real- ized. Among species of the Galveston area I have seen such in Periploma orbicularis Guppy, 1878 and Diplo- thyra smithit Tryon, 1862, neither closely related to each other nor to the Mactridae. But of the anatomical char- acters, I suspect only the small size of this specimen is abnormal in terms of other features; its presence above the substrate, as suggested by the epizoa growing on it, may indeed be unusual. Page 8 The diversity in soft anatomy of the Mactridae ap- pears to be larger than it is within most families of bivalves. I will not here try to summarize all of the liter- ature on this subject, which, though extensive and scat- tered, constitutes a mere beginning in comparison to the number of species whose anatomies are unknown. A well- developed foot is present in all species previously studied, and the atrophied foot of Raeta plicatella is unique. Fu- sion of the mantle margin behind the pedal opening varies. In some species, the mantle lobes are completely free between the anterior adductor and the siphonal pock- et. In others, the lobes are extensively held together along the posterior half of their margins by a fusion of a cuticular extension of the periostracum (Lutraria, fide Yonce, 1948). Dati (1898a) found free mantle lobes with papillae in Resania, but in Zenatia he says they are fused along their hind half, although he does not say whether the fusion is cuticular or represents cellular con- tinuity. In Raeta the fusion is definitely cellular, and this genus therefore represents a third condition of the mantle margin. A “fourth pallial opening” which is a small hole be- tween the mantle edges just below the siphonal pocket, is present in some Mactridae and other families, according to Ke.ioce (1915) and Yonce (1948), but such an open- ing is absent in Raeta. The wall lamellae of the waste canal, as these structures were termed by Kettoce (1915), have been given only passing attention in the literature except by that author and YoncE (1948), who termed them “mantle folds”. Dati (1898a) described similar folds in the New Zealand genera Resania and Zenatia, but called them “sensory lamellae”. The siphonal lamellae and wall lamellae of the waste canal may be structures limited to the Mactridae, al- though YoncE says that folds similar to the wall lamellae, but probably differing in function, occur in the Tellina- cean genera Scrobicularia, Abra and Macoma. A siphonal lamella forms a complete ring in the venerid Saxidomus as described and figured by Kettoce, but whether this is homologous to the semicircular lamella of the incurrent siphon of the mactrids is unknown. Among mactrids, the siphonal lamella is said to be absent in Lutraria (YonceE, 1948), and both that and the wall lamellae are absent in Spisula planulata Conrad, 1837, according to KELLOGG. Whether or not gills are pleated or smooth, without vertical folds seems to be a character which varies at the generic or specific level. RmEWoop (1903, pp. 237 ff.) found flat, homorhabdic (i.e., not-pleated) gills in four species of Mactridae on which he reported. Whether the pleated gills of Raeta plicatella have heterorhabdic fila- THE VELIGER Vol. 12; No. 1 ments at the grooves between the pleats was not deter- mined. The persistence of a crystalline style in bivalves which are not feeding, or at least while they are in the labora- tory for some time with minimal food, is a phenomenon which seems to be characteristic of most marine ones I have studied. This contrast with the oysters and unionids, which seem to resorb the style quickly when not feeding, and reform it in the- presence of food. The opening of the gonad into the pericardium, so that the gametes transverse the kidney lumen and emerge through the renopore is a point which bears checking in further studies. PELSENEER (1911, p. 100) thinks such a condition is primitive, and limited to some protobranchs, Anomiidae and Pectinidae. From his reservations on the matter, it is evident that the gonopore is difficult to detect in bivalves. Athough Moore (1931) called attention to the varied form of fecal pellets in marine mollusks, and suggested that careful study might yield valuable data on phylo- geny and food habits, nothing further seems to have been published on the subject. Moore did not describe the pellets of any mactrid bivalves. The feces of Raeta plicatella are markedly different from any he described in Pectinidae, Mytilidae, Tellinidae and Semelidae. The elab- orate pellets of R. plicatella are very similar to those of the pholad C'yrtopleura costata LinNAEUs, 1758, but differ in minor details (unpublished data). The presence of an osphradium in bivalves, homologous to that of snails, is a moot point. Only occasionally have such structures described above as an osphradium been noted. PELSENEER (1911, p. 112) calls these “sensory organ of the inhalent siphon”, and cites them in the Mactridae. The parasite found is evidently a larval tapeworm of the order Tetraphyllidea, the adults of which live in the intestine of elasmobranch fishes. Larvae of this type are called “Scolex pleuronectes Mit ver, 1788” or “Scolex polymorphus Rupotput, 1819”, binomials which do not have exact taxonomic significance. As Suip.ey (in SoutH- WELL, 1925, pp. ix-x) points out, “It is extremely diffi- cult to identify the larval form of a cestode with its parents. It is a wise tapeworm that knows its own father”. Apparently, the structures of the scolex in these larvae may vary considerably at different stages (ages) (SouTH- WELL, 1925, pp. 138 - 140). The one found in this study might be assigned to the family Phyllobothriidae, in lacking hooks on the scolex, yet the general form of the bothrydia is more like that of the other family in this order, Onchobothriidae, which, however, has no hooks in the scolex. Although most of these larval tetraphyl- lideans have been found in teleost fish, Hyman (1951, p. Vol. 12; No. 1 354) notes that they have been found in invertebrates of several groups, including mollusks, and she figures one (J. c., figure 131 D) from the foot of a clam. Part II. SYSTEMATICS Review of Raeta and Related Genera: Anatina ScHUMACHER, 1817 Raeta Gray, 1853 has sometimes been considered a dis- tinct genus, a position adopted here. Other writers have considered it indistinguishable from, or only a subgenus of, Anatina SCHUMACHER, 1817, or its junior synonym, Labi- osa Miter, 1832. The nomenclatural problem of Anatina versus Labiosa has been recently explored by KEEN (1961, q. v. for relevant bibliography), who gave good reasons for accepting the name Anatina as valid in the Mactridae. Moreover, she has shown that the type species of Anatina SCHUMACHER, 1817 is a western Atlantic species, Mactra anatina SPENGLER, 1802. This has been cited in much of the literature as Anatina or Labiosa lineata Say, 1822, but is now correctly identified as Anatina anatina (SPENG- LER, 1802). Despite KEEN’s study, the problem of whether to ac- cept Anatina SCHUMACHER or Labiosa MULLER has not been put to rest. OLsson (1961, p. 332) accepts Labiosa, as does Vokes (1967, p. 274), both apparently on the assumption that a use of the generic name Anatina by Bosc in 1816 is a validly proposed name, also a junior synonym of Laternula “BotTEN” Ropine, 1798. The latter is a relative of the anomalodesmacean genus Peri- ploma. According to that line of reasoning, Anatina would therefore not be available to use in the Mactridae. The point of contention seems to revolve on what Bosc (1816, p. 492) said in defining Anatina; his description is here quoted: “ANATINE, Anatina. Genre de coquilles bivalves établi par Lamarck aux dépens des Solens, sous la consideration d’une petite lame saillante 4 chaque valve en dedans ow s’attache le ligament. “Le Solen canard sert de type 4 ce genre, que est fort voisin des corbules et des Rupicoles. (B)”. If we consider, as Keen has correctly done, the type cited by Bosc to be vernacular and therefore invalid, one might still argue that this is a genus validly described but without species. Whereas it may be entirely possible to conceive of a genus without species in the realm of pure thought, as may be done in modern logic, such a concept is absurd when applied to real biological entities. THE VELIGER Page 9 Anatina anatina is a relatively rare shell on the beaches from New Jersey to Brazil. At Galveston it has not been found in the bays, but only as shells on the sandy beach and in a few dredged samples off shore. Apparently it does not occur in the Antilles. The differences between the shell of Anatina anatina and the species from the West Coast of the Americas have been discussed by Keen (1961), who pointed out that the West Coast species should be called Anatina cyprinus Woop, 1828. I could find only a single valve of the latter species in the National Collection. It is from Topolobampo, Sinaloa, Mexico. Otsson (1961) has given a descrip- tion and further distribution records of this species under the name Anatina anatina. As far as I can determine, the two species from the coasts of the Americas are the only ones which should be put in the genus Anatina ScHuUMA- CHER. The synonymy of the genus Anatina and the two spe- cies included in it will not be repeated here, since KEEN (1961) has provided a meticulous account of these earlier in this journal, and I have nothing to add. The anatomies of the soft parts of these species is unknown, but it is worth pointing out that many recent authors (e. g., YONGE, 1948) refer to the anatomy of the “‘Anatinacea” when they are referring to the anatomy of the Anomalodesma- cea of modern classification, i.e., the Periplomatidae, Lyonsiidae, Pandoridae and related groups. This confusion results from the fact that PELSENEER (1911 and earlier works), who paid scant attention to nomenclature, used the term Anatinacea based on Anatina as a genus in Periplomatidae. PELSENEER wrote most of what is known on the structure of the bizarre Anomalodesmacea, and most recent anatomists have unfortunately accepted his competency in nomenclature no less than in anatomy. The shell of the type species of Anatina SCHUMACHER has been studied in more detail than has been previously reported, and a description of it will be useful for com- parison with Raeta and related genera. Anatina anatina (SPENGLER, 1802) (Figures 7 to 10) Shell very thin, fragile, white, translucent, elongate ovoid, the front end somewhat more sharply rounded than the hind. Size moderate (65 mm long, 43 mm high, 28 mm wide). Equivalve, and slightly inequilateral, the umbos being just behind the midpoint of the length. Umbos touching, minute and distinctly prosogyrous. The hind end of the shell gapes. The umbonal fourth of the shell has faint concentric corrugations, parallel with the growth striae, forming ridges and grooves on the inner surface. Page 10 THE VELIGER Vol. 12; No. 1 The lower three fourths of the shell is smooth. A lunule is poorly defined by a shallow sulcus extending from the umbos in a broad arch about half the length of the Figure 7 Anatina anatina, dorsal view. Galveston, Texas, length 43 mm. antero-dorsal margin. This becomes wider toward its ante- rior end. On the medial side of the lunular sulcus is an opaque line not structurally differentiated on the outer surface. This is the line of attachment of the anterior hinge plate. The post-dorsal margin is about two-thirds as long as the antero-dorsal one. It is strongly turned later- ally, enhancing the posterior gape of the shell. A low rib, scarcely higher than wide, extends from the umbo to the post-ventral part of the shell: this may be a corcelet la- mella. In front of the rib, and separated from it by a space about half as wide as the space behind the rib, is a line defining an abrupt change in shell texture. This may be called the periostracal line. Along a narrow but poorly defined strip in front of the periostracal line vermiculate sculpture is evident. This is made up of minute wrinkles in the shell surface, joining and branching and mostly Figure 8 Anatina anatina. Galveston, Texas, length 33 mm directed radially. They are not present over the smooth part of the disk in larger shells, but are uniformly distrib- uted, although very faint, on all the adumbonal corru- gated region. In fresh shells, the surface of the thin, persistent, faint tan periostracum is silky in reflected light. But behind the periostracal line, the periostracum is lusterless, and less persistent. There are only coarse growth lines in the shell behind the line, and a moderately thick layer of opaque chalky material is deposited there between the periostracum and ostracum, The disk of the shell is distinctly swollen along a line from the umbo toward the antero-ventral angle. This gives the umbos the appearance of being directed back- ward, whereas in reality they are turned forward at their tips. Figure 9 Interior of same valve as shown in Figure 8. The pallial line is narrow, located close to the ventral edge of the valve, with slightly irregular dorsal margin. The anterior adductor scar is tear shaped, located direct- ly on the pallial line; it has a pallial line extending dorsal- ly from it to the front end of the hinge plate. Just above the anterior adductor scar the dorsal pallial line has a slight swelling, probably representing the anterior pedal retractor scar. The pallial sinus is large, rounded in front. It extends forward to a point below the umbos. Its lower side is well above the pallial line, not confluent with it. The posterior adductor scar is subtriangular, and the posterior pedal retractor scar constitutes a small con- stricted area confluent with the adductor at the dorsal tip of the latter. The corcelet ridge is evident internally as a shallow groove. Vol. 12; No. 1 THE VELIGER Page 11 The hinge plate is slightly thicker than the valve. The front and hind halves extend along the front and hind dorsal margins for about half the length of the latter. The front half of the hinge plate is thus slightly longer than the other; this part of the hinge plate is strongly oblique to the valve surface, so that there is a deep space between the two. Its free margin is deeply excavated in a gentle curve, so that the trough between the hinge plate and valve is minimized. The hind half of the hinge plate is almost flat and horizontal, with its free margin almost straight. The resilifer is a triangular pit below the umbo, with its lower margin projecting as a rounded curve below the hinge plate. Figure 10 Anatina anatina. Hinge of shell. Upper is right valve. The valves are of different shells. In the left valve, the cardinal tooth is moderately thick, and the sinus between the arms is large and deep. The sides of both arms are flat. The hind arm is about half as long as the front one. It projects over the resilifer as a free point. There is a thin antero-lateral lamella separating the front arm of the cardinal from the front hinge plate. A similar low, thin lamella is a little way behind the resilifer pit, separating it from the hind hinge plate. These two lamellae reach to the free margin of the plate, forming large oblique angles. The attachment of the tensiliar ligament is a semi- lunar depression on the shell margin, beginning at and extending behind the umbo. This depression extends over the tip of the resilifer pit, concealing it. The front half of the curved (ventral) margin of the ligament pit is turned medially, and to its lower (front) surface is fused a small lamella projecting as a minute spine over the resilifer pit. This “spur” lamella is parallel to the hind ramus of the cardinal, separated from it by a deep groove which receives the hind cardinal ramus of the right valve. In the right hinge the resilifer and ligamental shelf are much the same as in the left. There is also a single posterior lamella a little way behind the resilifer, separ- ating it from the shallow trough of the hind hinge plate. The cardinal and antero-lateral lamellae are different from those of the left hinge. The cardinal is chevron shaped, with the posterior arm straight and about half as long as the anterior arm; the dorsal surface of the hind arm is fused to the medially turned edge of the ligamental plate, and the lower end of this arm extends free over the cavity of the resilifer; the medial (free) margins of the two arms have a deep excavation where they meet at the apex of the chevron. The anterior arm is sharply curved in its upper half, by being bent forward. This part is fused with the umbonal part of the antero- lateral lamella, which projects free from the lower part of the front arm of the cardinal, as a minute but thick and consistent structure. The lateral lamellae of this species are probably homo- logous to the lateral teeth of other heterodonts, and indeed of other mactrids such as Spisula and Mactra. But in Anatina and Raeta they are more like cardinal teeth, radiating from the umbo, but not paralleling either the shell margin or the margin of the hinge plate; there is moreover only a single front and hind lateral lamella in both the right and left valves, whereas in Mactra, Spisula and some other genera, there is a single one before and behind in the left valve which fit between a pair at each place in the right valve. Also, in the latter genera, the laterals are parallel to the shell margin and, of course, to the margin of the hinge plate. The oblique, single lateral lamellae of Anatina and Raeta remind one of the laterals of the Cardiidae, which curve out as low ridges in a radiating arc from the umbo, on the inner surface of the shell. Whatever the soft anatomy of Anatina may disclose, the characters of its shell seem sufficiently diverse from Raeta to separate the two generically; the presence of the periostracal line and the lateral flexing of the post- dorsal shell margin in Anatina are characters not present in Raeta. A lunule is defined in Anatzna, but not in Raeta; the antero-ventral swelling of the disk is less pronounced Page 12 THE VELIGER Vol. 12; No. 1 in Anatina; the corrugations are limited to the umbonal third of the shell in Anatina, but extend to the ventral margin in Raeta; the corcelet ridge is pronounced in Anatina, but its presence is indicated by a mere cessation of the corrugations near the post-dorsal margin, with no radial ridge per se in Raeta. In the right valve of Raeta, the anterior lamella is directly in line with the front ramus of the cardinal tooth, which is flat, and the ramus and lamella are separated by a notch (Figure 12). In A. ana- tina, the front ramus of the cardinal of the right hinge is bent above, almost as long as the front lamella, which is beside it and free from it below (Figure 10). The vermiculate texture is common to both Anatina and Raeta. The periostracal chalk deposit, so pronounced in Anatina, may have become a lost character in Raeta s.s., but it is present in Raetina. Raeta Gray, 1853 The genus Raeta Gray, 1853 (Ann. Mag. Nat. Hist., Ser. 2, vol. 11, p. 43) was briefly described and typed by original designation and monotypy, “R. campechensis’’, which isa junior synonym of Lutraria plicatella LaMARCK, 1818. Raeta plicatella (Lamarck, 1818) (Figures 11 to 13) Lutraria plicatella Lamarck, 1818, Hist. Nat. Anim. sans Vert. 5: 470. Not figured; refers to GMELIN p. 3257, and CHEM- nitz Conch. Cab. 6, tab. 23, fig. 231 with a question mark. Type locality, “Probablement l’Océan indien.” Lutraria canaliculata Say, 1822, Journ. Acad. Nat. Sci. Phila. 2: 311 - 312. Not figured. Type locality, “Maryland and as far south as East Florida.” Mactra campechensis Gray, 1825, Ann. of Philos., N.S., 9: 135. Not described or figured; refers to “List. 304 (sic) f. 141”, evidently Lister, 1770, the second or Huddles- ford edition, where f. 141 of plate 308 (not 304) is a creditable figure of this species, with the words, “a sinu campeche” evidently indicating the type locality as the Bay of Campeche, Mexico. Raeta perspicua Hutton, 1873. Cat. Marine Moll. New Zea- land, p. 65. Not figured. Type locality (erroneously) New Zealand. 1913, SurzrR, Man. New Zealand Moll., p. 970, Atlas (1915), plt. 60, fig. 5. Oxtver (1923: 184) notes that this is a synonym of R. canaliculata Say, incorrectly attributed to New Zealand: Labiosa (Raeta) plicatella Lamarck. 1917, Lamy, Journ. de Conchyliol. Ser.-4,-42: 353 - 354; plt. 7, fig. 6 (photograph of holotype). 6% The description and figures cited by Lamarck in de- scribing Lutraria plicatella were insufficient to recognize this species, and he furthermore thought it came from the Indo-Pacific area, but expressed doubt. Lamy (1917) published a photograph of the holotype of Lamarck’s species which is unmistakably the species of the western Atlantic coasts. Meanwhile, it has been extensively cited in the literature under the trivial name applied by Say, and in combination with various generic names. HUTTON redescribed and named this species from a shell which he attributed to New Zealand, but which had evidently come from elsewhere, as pointed out by Oxtver. There are apparently no living species of Raeta or Raetella in New Zealand. Figure 11 Raeta plicatella, dorsal view of shell 25 mm long, Galveston Beach. The hole was probably made by a shore bird. Shell of moderate size (length 72, height 60, width 40 mm), thin, white, ovoid in side view, equivalve and gaping slightly behind; subequilateral, the umbos being slightly closer to the hind end. Umbos small, but swollen and prominent, touching each other and turned slightly but distinctly forward. The whole outer surface has prom- inent concentric ribs, rounded, poorly defined and with the grooves between slightly wider. These extend through the shell structure, producing a corrugated inner surface. In shells longer than 55 mm, the ribs tend to be more irregular and obliterated along the margin, with the inner surface smooth there. Fine radial wrinkles, closely spaced, are present on the ribs. These are most prominent on the lower third and hind slope of larger shells, where they extend into the grooves as well, and tend to anastomose. The wrinkles are part of the outer shell layer. The thin, light tan periostracum is smooth, closely adherent, but absent from even slightly worn shells. The front dorsal margin is gently convex, and continues in an even curve into the ventral margin, which is more convex. The hind dorsal margin has about the same curvature as the front, but it is shorter, slopes more abruptly from the hori- Vol. 12; No. 1 zontal; it meets the ventral margin in an obtusely rounded angle. There is no lunule; a narrow corcelet is poorly defined along the post-dorsal margin, extending to its post-ventral angle. This is formed merely by the con- centric ribs turning abruptly umbonad along this line, becoming much weaker, and lacking the vermiculate micro ridges present in front of the line. The disk is greatly inflated from the umbo to the antero- ventral angle. A wide, shallow trough separates the disk from the post-dorsal slope, which is somewhat flattened. The shell margin inside is smooth and sharp, the sur- face of the interior is subporcellaneous. The pallial line is thin, but prominent and continuous, with a large sinus reaching half-way forward and with rounded or usually acutely pointed tip. Its upper border has a rounded angle midway its length. The lower border is well separated from the pallial line proper. The anterior adductor muscle scar is thin and very elongate, narrowing acutely above. Figure 12 Right (upper) and left hinges of Raeta plicatella. The tensiliar ligament is present in the left valve only, but the two halves of the resilium are present in their respective valves. THE VELIGER Page 13 The hind one is oval to subquadrate, with a small posterior pedal retractor scar confluent at its upper end. The hinge plate is only slightly thicker than the rest of the shell. The hind half is vertical and flat, and of uniform width. It extends along the upper two-thirds of the hind margin. The front part has the shape of an acutely ta- pered triangle; it is about a third as long as the hind part. It is attached obliquely to the shell. Directly below the umbo there is a large triangular resilifer, deeply ex- cavated and extending to the tip of the umbo, but its upper third is covered by shell. The base of the triangle is well below the rest of the hinge plate margin. The lig- ament is entirely internal, and divided into resilium and tensilium, well separated. The resilium has the form of two tapering horns, slightly curved, with their apices in the covered upper parts of the resilifers, directly below the umbos, and the faces of their circular bases meeting in the midline. The faces of the opposed bases are con- cave, with only the peripheral margins touching. The concavity extends upward on the medial side of the horns to the tip of each. The outer, lateral side of each horn is flattened and about a third again as large as the opposing faces, so that the two halves of the resilium have the shape of an hour glass when viewed along the median plane of the animal. The tensiliar part of the ligament is elongate lanceo- late, short, attached at the shell margin beginning just below the umbos, and with its axis sloping ventrally, away from the shell margin behind. Only the anterior tip is visible externally. The tensilium is attached to a hinge buttress, a lamella which parallels the hind side of the resilifer triangle, and which extends almost to the free hinge margin. It is obliquely attached to the hinge plate, so that its medial surface, to which the tensilium is at- tached, slopes downward and backward toward the resi- lifer cavity. Its upper third is attached to the shell margin completely roofing over the subumbonal tip of the trough on the hind half of the hinge plate. The lower half of the tensiliar lamella is acute, and extends over the trough slightly. Along the tensiliar lamella, below the tensilium, there arises an oblique buttress lamella, of the hind ramus of the cardinal tooth. It completely conceals the upper fourth of the resilifer cavity, covering the apical end of the resilium. Along the margin of this lamella which ap- proaches the cardinal tooth, there is a sharp spine pro- jecting toward the middle of the base of the resilifer. A single cardinal tooth in each valve has the shape of an inverted V, with the rami diverging at slightly less than a right angle, and the apex directly below the umbo, separated from it only by the thin hinge margin. The left cardinal fits into the cavity of the right one. The outer Page 14 THE VELIGER Vol. 12; No. 1 faces of the left cardinal are smooth and flat, but the two rami are thick and fused so that the cavity of its chevron is nearly filled solid, leaving only a vague medial sulcus on the ventral side. Each cardinal tooth is about half as high as the width of the hinge margin, and the hind ramus of each projects over the resilifer. A deep groove along and above the base of each ramus of the left cardinal receives the right cardinal. This groove Figure 13 Upper: Raeta plicatella from Galveston, 63 mm long. Lower: Raeta undulata from Topolobampo, Mexico, 71 mm long. is formed behind by the margin of the subtensiliar butt- ress and its prominent spine, and in front by a lamella of moderate thickness, normal to the hinge plate and parallel to the anterior ramus of the left cardinal. This is the anterior lateral lamella. Its umbonal half is low, and connected to the inner side of the shell by a small buttress parallel to the hinge plate; this is the anterior buttress of the cardinal tooth and it reofs the extreme tip of the anterior hinge plate trough. The lower half of the anterior lamella is raised into a quadrate tooth-like process. In the right valve the hind ramus of the cardinal tooth is fused with the spine of the buttress arising below the tensilium, but not completely, so that it and the spine appear as a bifid tooth. The front ramus is the same length as the hind one, but it appears to be twice as long, because of a quadrate lamella directly below and in line with it. It is separated from the quadrate lamella by a small but consistent notch. This quadrate lamella is the antero-lat- eral lamella. The front ramus of the right cardinal has a thick lamellar buttress extending from its free margin outward and upward to the inner surface of the shell, and roofing the trough of the hinge plate. In both valves there is a single posterior lateral lamella, running from the umbo toward the ventral margin. This lamella is bent upward toward the shell margin, so that its attachment on the hinge plate is oblique, and poorly defined in medial view. Evidently these two lamellae are directly opposite each other in the closed shell, and one does not insert above the other, since neither crosses the median plane. But they may be homologous to the poste- rior lateral teeth of other mactrids. Raeta (Raeta) undulata (Goutp, 1851) (Figure 13, lower shell) Lutraria undulata Gou.p, 1851, Proc. Boston Soc. Nat. Hist. 4: 89. Not figured. Type locality: La Paz, Lower Califor- nia. 1853, Gouxp, Boston Journ. Nat. Hist. 6: 391; plt. 15, fig. 7. Oxproyp (1924) has copied the English translation of the description by GouLp of this species which he pub- lished in 1853. She also republished (J. c., plt. 21, fig. 11) his original figure, an external view of a left valve. His figure 7 also includes a dorsal view of both valves, showing a prominent posterior gape. The figure he published shows very regular corrugations from beak to ventral margin, but in the larger specimens I have seen, these ridges tend to be obliterated toward the lower margin, more so than in Raeta plicatella. Perhaps his figure was drawn from a juvenile shell. Vol. 12; No. 1 THE VELIGER Page 15 The shell of Raeta undulata is similar to that of R. plicatella in the coarse corrugations well covered by ver- miculations, and in the hinge, which also has an oblique postero-lateral lamella in each valve. It differs chiefly in the more rounded, posterior end of the shell, in having the umbos about midway the length or slightly forward of that point, instead of well behind, and the corcelet line along the postero-dorsal shell margin is distinctly farther from the margin than in the east coast species. The chalk deposit of the periostracum seems to be absent. More extensive synonymies are given by Otsson (1961), all to secondary references however. This species may have the same ecological distribution as the one on the East Coast, just beyond the surf zone along sandy shores. KEEN (1958) notes that “Beach valves are fairly common, but entire specimens are hard to find, even by dredging”. (Raetina) Dat, 1898 Raetina Dau, 1895, Proc. Malacol. Soc. London 1: 212, Type R. indica DALL (nom. nud.). Raetina Dau, 1898, Trans. Wagner Free Inst. Sci. 3 (4) : 822, Type by O. D. and M Raeta (Raetina) indica Datx, 1898, which is a junior synonym of Mactra pellicula REEVE. This is similar in size and shape to Raeta s.s. The hinge plate is thick, almost vertical behind, and the groove on it is shallow and rounded in cross section. Sculpture is continuous top to bottom, and from front to hind end; it consists of corrugations evident on the inner surface of the shell, and the corrugations are in line with the growth lines, not oblique. Vermiculate texture is present, but very weak and limited in area. The main reasons for recognizing this as a distinct sub- genus are two: (1) the sculpture is more delicate, the corrugations being finer and more closely spaced than in the typical subgenus; (2) the posterior lamella, running obliquely from the umbo across the front end of the hind hinge plate, is absent in this subgenus. Chalky deposits in this periostracum, which occur in Anatina, may be present in Raetina, but seem to be absent in Raeta s. s. This genus was essentially a nude name as of 1895, diagnosed only by indication of the type species, which was not described until 1898. Raeta (Raetina) pellicula (REEvE, 1854) (Figures 14 and 15) Mactra pellicula “DEsuayEs” Reeve, 1854 (May). Conch. Icon 8: Monograph Mactra, plt. 21, fig. 124. Type locali- ty: Japan. Mactra anatinoides Reeve, 1854. Conch. Icon. 8: Monograph Mactra, plt. 21, fig. 123. Type locality unknown. Mactra pellicula DesuayeEs, 1855. Proc. Zool. Soc. London 22: 68. Not figured. Type locality: “Japan (col. Cuming) .” Raeta grayi H. Avams, 1872. Proc. Zool. Soc. London, p13; pit. 3, fig. 23. Type locality: Borneo. Raeta abercrombiei Metviti, 1893. (In MEtvitt &« ABER- cromBIE, 1893) Manchester Lit. & Philos. Soc. Mem. & Proc. Ser. 4, 7: 32 (nom. nud.) ; MrtviLx, 1893, Ibid., p. 65; plt. 1, fig. 25. Type locality: Bombay, India. Raeta (Raetina) indica Daur, 1895. Proc. Malacol. Soc. Lon- don 1: 212 (nom. nud.) . Raeta (Raetina) indica Dat, 1898. Trans. Wagner Free Inst. Sci. 3 (4) : 882 - 883, footnote. Not figured. Type locality: Bombay, India. Anatina (Raetina) indica Dau, 1925. Proc. U.S. Nat. Mus. 66 (17): 2; plt. 20, fig. 2. Holotype. Raeta jickelii Sturany, 1905. Nachrichtsbl. d. deutsch, Mala- kol. Ges. 37t year, pp. 133 - 134; text figs. a, b, and c, p. 133. Type locality: “Massaua” (Massawa, Ethiopia, south- west coast of the Red Sea). Raeta magnifica Yokoyama, 1922. Journ. Coll. Sci. Tokyo, 44: 132; plt. 8, figs. 12, 13. Type locality: Fossil, Tega (Kizaki), Japan. Raeta fragilis GraBau & Kinc, 1928. Shells of Peitaiho, pp. 190 - 192; plt. 7, fig. 54. Type locality: Peitaiho (Yellow Sea, China). This species has a very wide range, from the shores of the Red Sea, to India, Borneo, China and Japan. It evi- dently shows some variation in form, particularly in the Figure 14 Holotype of Raeta (Raetina) indica Dart (= Raeta pellicula). The dark shading along the postero-dorsal margin indicates peri- ostracal chalk deposit. Length, 43 mm. length and acuteness of the rostrum. The short-rostrate forms are what authors have called Raeta anatinoides (REEVE) and, judging from the figure, R. grayi H. Apams. ToMLIn (1924) pointed out that the species names pub- Page 16 lished by Reeve (1854) in his monograph of Mactra predate all species named by DESHAYES in 1854 and 1855, even though REEvE attributes many names to DESHAYES. For exact date on the several species, see the paper by Tomun. Elsewhere Tomun (1931) declares R. aber- crombici identical with R. grayi after comparing the holo- types of the two species. Although Dati was quite sure his R. indica was distinct from R. abercrombiei, the only differences he cited were “form and proportion”. The holotype of R. indica Dat shows nosignificant differences from a shell in the National Collection from Japan, which in turn fits quite well with the concept of R. pellicula Reeve. No one who has studied the group seems to have seen more than a few shells from different places, and the above synonymy can only be tentative. Figure 15 Interior of same valve as shown in Figure 14. Like the species of Raetas. s., all records of this species are from the beaches of continents or the larger conti- nental islands. It may be absent in the small oceanic is- lands of the Indo-Pacific, which seem indeed to have few mactrids of any genus. Probably this species lives at the outer edge of the surf zone on sandy shores. The following description is based on the holotype of Raeta indica Daut, which is a single left valve, USNM 90276, with the words “Bombay” and “Wesleyan Univ.” on the label. Length 43, height 28, semidiameter 9 mm. Shell elon- gate ovoid, front end evenly rounded, hind end drawn out in an obtusely rounded rostrum. Probably equivalve, and almost equilateral, the umbos being slightly closer to the front end. Umbos prominent, touching, turned slightly forward. Shell very thin, translucent, with numer- THE VELIGER Vol. 12; No. 1 ous concentric ribs and troughs, which are undulations of the shell substance affecting both surfaces. The undula- tions are regular, from umbo to ventral margin, and con- tinuous, except along the post-dorsal slope. They are parallel to the growth striae. Color white. No lunule. Corcelet (or escutcheon?) defined only by rapid dimi- nution of the ribs along a poorly defined line near and parallel to the post-dorsal margin. No epidermis is evident, but there is a chalky white deposit postero-ventrally. A few faint vermiculations, similar to those of Raeta plica- tella, are evident only along the post-ventral part of the valve. The roundly pointed pallial sinus reaches as far for- ward as the umbo. Its lower margin is separated from the pallial line. Muscle scars could not be seen in the slightly worn holotype (but Datu illustrated them as typical of Raeta s.s.). The hinge is typical of Raeta, except that there is no hind radiating lamella between the resilifer and the groove of the post hinge plate. The com- parable buttress of the front hinge plate groove is slightly broken, but it has a thick base. The posterior gape between the valves must have been small. I cannot see any specific differences in the holotype and a pair of matched valves from Japan (Hirase Coll., US NM 344967, 53 mm long, 41 mm high). The Japanese specimen is larger, not as acuminately rostrate behind. There is no chalk deposit on its posterior slope, but a faint, narrow corcelet ridge seems to be present, slightly forward of the line medial of which the concentric ribs become mere growth striae, though pronounced. The form of both the Indian and Japanese shells is easily distinguishable from Raeta plicatella and R. undu- lata, the ribs are more numerous and finer, the posterior lateral lamella is lacking in both specimens of the oriental species. Raetella Datu, 1898 Raetella Dax, 1895. Proc. Malacol. Soc. London 1: 212. Type by O.D. and M. Raetella tenuis (Hinps MS.) Day (nom. nud.) . Raetella Dau, 1898. Trans. Wagner Free Inst. Sci. 6 (4): 882 - 883. Type species by O. D. Raetella tenuis “Hinps” Dat, 1898, which is a junior synonym of Poromya pul- chella A. ADAMS & REEvE, 1850. Raetellops Hae, 1952. Genera of Japanese Shells, Pelecypoda No. 3: 197, as subgenus of Raeta Gray, 1853. Type by O.D., Poromya pulchella A. ApaMs & REEvE, 1850. This name was essentially nude when proposed by Dati in 1895, being diagnosed only by designation of the type species, which was not described until 1898. Vol. 12; No. 1 THE VELIGER Page 17 Shells of this genus are much smaller in size than those of Raeta, and the ribs of Raetella are proportionately coarser. They are, moreover, slightly oblique to the lines of growth. The shells have a peculiar opalescent luster, which Datu called a “‘pseudo-nacreous surface”. Vermi- culate texture and chalky periostracal deposit are absent. Although Dati (1898, p. 882) said the “dorsal areas [are] well defined”, there is no structural feature on the external surface defining them; their presence is merely simulated by the attachment of the hinge plate showing through the translucent shell. The hinge plate lamellae are very thin, and the front one is only slightly shorter than the hind one. Both front and hind parts are almost horizontal, with the space between them and the adjacent valve surface very deep. In Raeta and Raetina the posterior half of the hinge plate is essentially vertical and thick, with swollen, rounded free margin. The lateral teeth are paral- lel to the hinge plate margin, not strongly oblique to it, as in Raeta and Raetina. Moreover, there is a single hind lateral in the left valve, but two in the right, in the pattern quite general in Mactridae. But there is only a single, short antero-lateral in each valve. This genus may extend to greater depths than do Raeta or Raetina, which, like most mactrids, are shallow water inhabitants. As presently known, it seems limited to the eastern coast of Asia and larger continental islands along it. Raetella pulchella (A. ADAMS & REEvE, 1850) (Figures 16 to 19) Poromya pulchella A. ADAMS & REEVE, 1850. Voy. Samarang. Zool., Mollusca, p. 83; plt. 23, fig. 1. Type locality: Shores of Borneo. Mactra rostralis “DESHAYES” REEvE, 1854. Conch. Icon. 8, Monogr. Mactra, plt. 21, fig. 119. Type locality: “China Seas?” Mactra rostralis DEsHaYEs, 1855. Proc. Zool. Soc. London, p. 69. Not figured. Type locality: Japan. Raeta yokohamensis Pirssry, 1895. Cat. Marine Moll. Japan . collected by F Stearns, p. 119; plt. 3, figs. 4, 5. Type locality: Yokohama, Japan. Raetella tenuis “Hinps” Datu, 1898. Trans. Wagner Free Inst. Sci. 3 (4): 883 (footnote). Not figured. Type locality: Hong Kong Harbor, about 8 feet of water. Raeta elliptica Yokoyama, 1922. Journ. Coll. Sci. Tokyo 44: 131 - 132; plt. 8, fig. 7. Type locality: Fossil, Tega, Ka- menari, Kioroshi (Japan). ; Raetella rostralis has been considered a synonym of R. pulchella by most authors, as pointed out by Lamy (1917). On the basis of the original descriptions and illustrations of the several nominal species, I agree with Hape (1952) that Raeta yokohamensis and Raeta elliptica should be added to the synonymy. The specimen on which Dati based his name Raetella tenuis ““Hinps” also seems con- specific. Hinps seems never to have named such a species, and Dau (1898) received the name from P. P. Carpenter, who evidently took it from a label in the British Museum. The following description is based on the holotype of Raetella tenuis “Hinps” Datu. The type lot is USNM 519, and the label has written on it “4-8 ft., mud, in har- bor, Hong Kong, Stimpson”. The holotype consists of disjoined valves of one shell; the right valve is only broken around the ventral and posterior margin, but the left is fragmented into several large pieces. Shell small (13 mm long, 10mm high, 3.0 mm semi- diameter), ovate in profile, evenly rounded in front and Figure 16 Holotype of Raetella tenuis “Hinps” Dati (= Raetella pulchella) . Length, 13 mm. Page 18 below, drawn out in a short but rather acute rostrum behind. The disk is very inflated, almost hemispherical, but the inflation is even, without a prominent axis from umbo to antero-ventral margin. Umbo 5/7 the length from the front end. Color white. A thin, closely adhering periostracum is light tan. The outer surface has a faint opalescent irides- cence. Sculpture of about 23 concentric ribs, which are regularly spaced from umbo to ventral margin, but which do not extend to the antero-dorsal margin nor onto the rostrum. There is a slight, very broad, shallow sulcus be- tween the disk and the post-dorsal region, but no demar- cation of an escutcheon or corcelet. There is no chalky deposit in the periostracum, and no radiating vermiculate texture. The concentric ribs are slightly oblique to the lines of growth, and this is most prominent on the antero- ventral part of the disk. A lunule is simulated by the attachment of the anterior hinge plate. Shell very thin, the ribs forming undulations on the inside, which is porcellaneous. Attachment scars not evi- dent in the holotype. Figure 17 Hinge of holotype of Raetella tenuis “Hinps” Dati (= Raetella pulchella) In the right valve a V-shaped cardinal tooth is adjacent to and points toward the umbo. The two arms are about equal in length, moderately thick, and with a broad, deep space between them. A deep cleft separates the medial part of their junction, at the apex of the V (poorly shown in Figure 17; see Figure 19). The posterior arm is separated by a narrow space from the front edge of the resilifer. Along the base of the anterior ramus there is a very thin buttress which crosses obliquely the space THE VELIGER Vol. 12; No. 1 Figure 18 Upper: Raetella pulchella from Japan (USNM 249247) showing pallial sinus. Lower: Raetella pulchella from Fukura, Awaji, Japan (USNM 344966) 23 mm long. Note relatively smooth surface and poorly rostrate hind end. over the cavity of the anterior hinge plate and attaches to the shell. A lamella in line with the anterior arm of the cardinal and also the anterior hinge plate lamella seems to be broken off, flush with the latter, in the right valve of the holotype (see Figure 19). The anterior hinge plate is very thin, with sharp free margin. It is almost horizon- tal, paralleling the dorsal margin of the shell and at- taching rather far laterally. The cavity between the front hinge plate and the shell is thus very deep and narrow. The front hinge plate lamella is only slightly shorter than the hind one. The hind hinge plate is not so wide as the front, and the cavity between it and the shell is not so deep. No escutcheonal area is defined on the outer sur- face by its attachment. It is equally thin, with sharp margin. Along the umbonal fourth this plate is extended medially slightly, forming a lateral tooth. Above it on the margin of the shell is another very slight lamella, not as long as the lower one, forming an upper posterior lateral tooth. The resilifer is small, triangular, directed down- ward from the umbo. Tensilium very short, directly under the umbo, and not separated from the resilifer by any shelly material except the small ledge on which it sits. Vol. 12; No. 1 THE VELIGER Page 19 Hinge of the left valve similar to that of the right. The two rami of the V-shaped cardinal tooth are thicker, smaller, and evidently fit inside the right cardinal. Above the left cardinal and between it and the umbo is a small but prominent tooth-like process, with an inverted V- shape, the front ramus of which is very short. The hind ramus of this little tooth margins the upper part of the resilifer. A lamellar extension of the anterior hinge plate seems to be present at the umbonal end but it is badly broken. There is no dorsal lateral tooth on the shell mar- gin. A very thin prominent lamella radiates from the umbo and separates the hind hinge plate from the cardinal area. Two small lamellae in the front hinge plate cavity of the left valve do not extend to the median plate of the shell, and are possibly abnormal. ~~ Cho ee Z ~~ 5 Sy? Sas Bae SNS ae eee nS Ses i LELEF SWS al = Figure 19 Hinge of Raetella pulchella from Japan (USNM 249247). The drawings were made at slightly different angles, causing the resilifer of the left (lower) valve to appear smaller than that of right hinge. The holotype of DaLt’s nominal species is more inflated over the disk and more rostrate behind than most speci- mens of the 14 lots in the National Collection from Japan. It fits the concept of “Mactra” rostralis better than “M.”’ pulchella, but I think it is only an extreme variant of this highly variable species (cf. Figure 18). Some shells from Japan are larger (20mm long, 14mm high). The Japanese shells are slightly gaping behind, and equivalve. Sculpture on them varies considerably, some shells being almost smooth, with ribs limited to the ventral part, not present on the umbo. Most Japanese shells are less rostrate behind than is the holotype of Da.t’s species; they are more equilateral, and not as inflated over the disk. Figure 19 is a drawing of the hinge of a Japanese specimen, showing the prominent short anterior lateral tooth, directly on the hinge plate margin. Each tooth curves outward from the umbo, as shown by the dotted lines at their bases. The left antero-lateral slips above the right one when the valves close. The left valve has a single postero-lateral tooth, which fits between the two on the right valve. All these postero-laterals are developed as elongate lamellae directly on the valve margin and hinge plate margin, and parallel to them. A large lot from Siam (USNM 477293) has very thin shells which are non-rostrate, well sculptured, and of a uniform small size. SPECIES INCERTAE SEDIS Raeta meridionalis Tate, 1889 (Figure 20) Raeta meridionalis Tate, 1889. Trans. Proc. Roy. Soc. South Austral. 11: 61; plt. 11, fig. 3. Type locality: Aldinga Bay (South Australia). ?Labiosa meridionalis Tate, 1889. HEpLEy, 1900. Proc. Linn. Soc. New South Wales 25: 497; plt. 25, figs. 5 - 9. Locali- ty: Chinaman’s Beach, Middle Harbour (Australia). Tate’s original description of this species is here quoted, and Figure 20 (left) is a tracing of his original drawing. “Shell whitish, very thin, translucent; ovately-suboblong, mod- erately convex antemedially, posteriorly gaping; umbo sub- acute, curved forward, situated in the anterior three-sevenths. “Anterior margin regularly rounded, ventral margin strongly arched; dorsal line sloping on both sides, more so in front than behind; posterior side narrowed and depressed, its margin somewhat squarely truncated and slightly reflected. There is an ill defined depressed post-dorsal area, but no umbonal ridge. “Sinus widely rounded, horizontal, reaching to the center, visible on the exterior. “Surface marked by fine lines of growth, which become more conspicuous and finely wrinkled on the post-dorsal area. “Dimensions: Antero-posterior diameter, 35; umbo-ventral di- ameter, 30; sectional diameter of left valve, 8 millimeters. “Locality — one valve collected by Mr. Magarey on the beach of Aldinga Bay.” The species described by Tate has the shape of Mactra anatinoides REEVE, which I have considered a junior syn- onym of Raeta pellicula. But the sculpture is most un- usual for a Raeta. It is apparently so thin that the pallial sinus shows through the shell, yet strong concentric cor- rugations seem to be lacking, and there is no corcelet line or ridge along the post-dorsal slope. I have seen no speci- mens. This species evidently lives near the shore of sandy Page 20 THE VELIGER Vol. 12; No. 1 beaches and it may be quite rare. A copy of the original figure is given by Cotron & Goprrey (1938) and by ALLEN (1959). Incidentally, Cotron’s (1961, p. 343) reference to the original description of this species (“TATE, 1887, Trans. and Proc. Roy. Soc. So. Austr. 9: 68 - 69, pl. 5, fig. 4, Montacuta meridionalis’) is evidently in error, for the description and figure of Montacuta meridionalis Tate, 1887 clearly refers to a leptonid bivalve, and not to R. meridionalis (Tate, 1889). PL. XXV. 7 eS es / Cae — rE 2) SSS Sere —— LG fy \) i ee i if Bile “ , 4 Y if [ : Hai AAv! nti Wo zat Wo yy as Hl 4 9S ye Figure 20 Left: Tracing of figure 3 of plate 11, TaTE, 1889, the original drawing of Raeta meridionalis Tate. Right: Figures 5-9 of plate 25 of HEDLEY, 1900, which he also identified as Raeta meridionalis TATE. The problem is further confused by the account Hep- LEY (1900) gave of 14 additional specimens which he found. Although his shells were reported to be authenti- cated by Tate, the size, shape and sculpture all suggest a species of the Raetella pulchella group. The peculiar drawing of the sculpture also suggests the concentric undulations are slightly oblique to the lines of growth, as in Raetella, and not vermiculate textural features char- acteristic of Raeta and Raetina. HeDLEy’s remarks and figures are here reproduced (Figure 20, right). “This species has hitherto been known from a single valve found on the beach of Aldinga Bay, South Australia. This year I have taken a whole shell containing part of the animal, and on another occasion a broken valve on “Chinaman’s Beach”, Middle Harbour. Prof. Tate, to whom one valve was submitted, kindly informs me that there is no essential difference between it and the type of meridionalis. My specimens are smaller, being 28 mm in length and 21 mm in height. Being perfect, I have utilized my example to draw the valves in apposition and other details not obtainable from the single valve hitherto known. “Though disagreeing by vermiculate sculpture, the species seems to me nearer to the subgenus Raetella, DALL, than to any other division of Labiosa.” Possibly there are two species along the shore of south- ern Australia, one described by HeEpxey being similar to Raetella pulchella, the other to a sub-oval Raeta (Rae- tina) pellicula. SMrrH (1914, p. 150) cites Cypricia grayi H. Apvams (which is Raeta grayi H. ApaMs cited above in the synonymy of Raeta pellicula) from Queensland, Australia, and notes a reference which I have not seen, which does the same (HeEptey, 1910, Rep. Austral. Assoc. Adv. Sci. for 1909, p. 351). Nick es (1950, p. 209) cites a “Labiosa vitrea Gray” from the west coast of Africa (“Casamance a la Guinée frangaise; Congo frangais”), with a brief description and figure. The general shape is that of Raetella, but the size is larger (up to 50 mm long). There are regular undula- tions only on the posterior slope, which is unusual for this genus. This is possibly Mactra vitrea Gray, 1837 (Charlesworth’s Mag. Nat. Hist., New Ser., vol. 1, p. 372, not figured) described from unknown locality. Lamy (1917, pp. 273 - 274) placed this in the subgenus Mact- rinula of Mactra, but did not figure or describe it, nor did he know the locality of the material which he examined in the Paris Museum. I have seen no specimens, and cannot comment on its possible membership in Anatina or Raeta. As Lamy (1917) has noted, Raeta lyrata “Hinps Ms.” H. « A. Apams (1856) is a nomen nudum, and Raeta bracheon Sturany, 1899 (p. 12; pl. 3, figs. 1-6; Gulf of Suez, 50 fathoms) belongs elsewhere. Lamy says it is Leptomya cochlearis Hinps, of the Scrobiculariidae. The Raeta tenera “DESHAYES” listed by H. & A. ADAMS possibly refers to “Mactra tenera Desh.” listed as a syn- onym of Mactra anatinoides, with query, by Reeve. As Tomutn (1924) implies, no such species seems to have been described by DEsuay Es. According to the Zoological Record, Li (1930) de- scribed a new species, Raeta maxima, but I have been unable to locate that article. Vol. 12; No. 1 THE VELIGER Page 21 SYSTEMATIC DISCUSSION Much essential information relevant to the phylogeny and life habits of this group is likely to be gained by further investigation of their anatomies. There are also characters of the shell which have not been given adequate atten- tion. Admittedly, the species of this review were chiefly considered on the basis of those traditionally grouped to- gether. Anatomical studies on these and other mactrid species may well indicate revisions of the classification quite different from that proposed by Dax (1895, 1898) and expanded by Lamy (1917). Several examples of shell characters whose significance is unexplored occurred to me during the present study. One is that thin-shelled mactrids generally have corrugated concentric sculpture, with the ridges affecting both the inner and outer shell surface, as in Raeta and Raetella, or they have a keel along the post-dorsal slope as in Anatina, Mactra alata, and M. fragilis; this keel I have called a corcelet, although aware that it may not be homologous to structures so named in other families. Perhaps the corrugations and keel are devices which strengthen the shell. In some species both are present, notably Harvella elegans from the tropical part of the western shores of the Americas. Mactra iheringi (Dati, 1897), from the east coast of South America, is very similar to H. elegans in size, shape and dentition, but it is a much thicker shell, with smooth external surface and no corrugations or post-dorsal ridge. That these two represent analogous species on the two sides of the continent should be given further study. Incidentally, Harvella elegans seems to have vermicu- late texture similar to that of Raeta plicatella, and the distribution of this feature among thin-shelled mactras with corrugated shells should be studied. In a rare species of the Indo-Pacific, Mactra (Mactrin- ula) plicataria Linnaeus, 1767, the front end of the shell is disproportionately elongate, with the hind end trun- cated, and a form recalling Donax. This genus has further developed a thin shell, with corrugate sculpture and ver- miculate texture very similar to Raeta. The disk, however, is not exceptionally swollen. In the group of Anatina, Raeta, and Raetella there is a more pronounced swelling of the disk, which is not me- dial, but extends more toward the front end of the shell. In its extreme form, such as found in Raeta s.s., a shape recalling that of Cuspidaria results. This is just the op- posite of the disk swollen along a line running postero- ventrally such as found in the Mytilidae and Carditidae. Raetella may be no more closely related to Raeta and Raetina than any of them are to Harvella or Mactrinula. The sculpture of Raetella recalls that of the West Ameri- can Tumbeziconcha, which, however, has the posterior end of the shell extended, and the obliquity of the ridges on that end, rather than on the front one. LITERATURE CITED ApaMs, ARTHUR & LoveLL Aucustus REEVE 1848-1850. The zoology of the voyage of H.M.S.Samarang, under the command of Captain Sir Edward Belcher. Mollusca. London, prts. 1-3: 1-87; 24 plts. ApaMs, HENRY 1872. Descriptions of fourteen new species of land and marine shells. Proc. Zool. Soc. London for 1872: 12-15; plt. 15 (June 1872) ApaMs, HEnry, « ARTHUR ADAMS 1853-1858. The genera of Recent Mollusca, arranged according to their organization. London; 1: vi-xl, 1-484; 2: 1-661: 3: plts. 1 - 138 ALLAN, Joyce K. 1950. Australian shells. Georgian House, Melbourne; 470 pp. Bosc, Louis AucusTIN GUILLAUME 1816. Anatine. In: Nouveau dictionaire d’histoire naturelle. vol. 1, p. 492. Deterville, Paris Cotton, BERNARD CHARLES 1961. South Australian mollusca. Adelaide, 363 pp. Cotton, BERNARD CHARLES & FRANK K. GopFREY 1938. The molluscs of South Australia. Part I - Pelecypoda. Frank Trigg, Govt. Printer, Adelaide, 314 pp. Dai, WILLIAM HEALEY 1895. Synopsis of a review of the genera of Recent and Ter- tiary Mactridae and Mesodesmatidae. Proc. Malacol. Soc. London 1 (5): 203 - 213 1890-1903. Contributions to the Tertiary fauna of Florida. Trans. Wagner Free Inst. Sci. 3 (1-6): 1654 pp.; 60 plts. [part 4, 1898, contains the data relevant to the present study]. 1898a. Note on the anatomy of Resania, Gray and Zenatia, Gray. Proc. Malacol. Soc. London 3 (2): 85 - 86 1925. _ Illustrations of unfigured types of shells in the collection of the United States National Museum. Proc. U.S. Nat. Mus. 66: 1 - 41; plts. 1 - 36 Desuayes, GERARD PAauL 1855. Descriptions of new species of shells, from the collection of Hugh Cuming, Esq. Proc. Zool. Soc. London for 1854 22: 62-72. (Forty seven new bivalves, all in Mactridae, are described. See Tomtin, 1924). (10 February 1855) GouLp, Aucustus ADDISON 1851. Descriptions of new shells from California, collected by Maj. William Rich and Lieut. T. P Greene, U.S.N. Proc. Boston Soc. Nat. Hist. 4: 87 - 93 1853. Descriptions of shells from the Gulf of California and the Pacific coasts of Mexico and California. Boston Journ. Nat. Hist. 6: 374 - 407; plts. 14 - 16 Gray, Joun Epwarp 1825. A list and descriptions of some species of shells not taken notice of by Lamarck. Ann. of Philos., New Ser. 9: 134 - 140; 407 - 415 W. L. Hawes, Govt. Printer Page 22 Gray, JoHN Epwarp, cont. 1837. A synoptical catalogue of the species of certain tribes or genera of shells contained in the collection of the British Mu- seum and the author’s cabinet; with descriptions of the new species. Charlesworth’s Mag. Nat. Hist. 1 (new ser.) : 370 to 376 1853. A revision of the genera of some of the families of con- chifera or bivalve shells. Ann. Mag. Nat. Hist., Ser. 2, 11: 33 - 44 Hase, TADASHIGE 1952. | Genera of Japanese shells. 187 - 278 HeEpDLEY, CHARLES 1900. Studies on Australian Mollusca, Part 2. Soc. New South Wales 25: 495 - 513; plts. 25, 26 Hutton, FREDERICK WOLLASTON 1873. Catalogue of the marine Mollusca of New Zealand with diagnoses of the species. Wellington (Colon. Mus. & Geol. Surv. Dept.) pp.i-xiv+1-116; 1 plt. (after 7 May 1873) Hyman, Lissy HENRIETTA 1951. The invertebrates: Platyhelminthes and Rhynchocoela, vol. 2, 550 pp., McGraw-Hill, New York Keen, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford, Calif. (Stanford Univ. Press) 1961. | What is Anatina anatina? The Veliger 4 (1): 9 to 12; 5 text figs. (1 July 1961) Kettocc, James LAWRENCE 1915. Ciliary mechanisms of lamellibranchs with descriptions of anatomy. Journ. Morphol. 26: 625 - 701. Lamarck, JEAN-BartisTe PreRRE ANTOINE DE MONET DE 1818. Histoire naturelle des animaux sans vertébres. Paris, 7 vols. Lamy, EpouaRD 1917-1918. Revision des Mactridae vivants du Muséum d’Histoire Naturelle de Paris. Journ: de Conchyl. 63 (3) : 173 - 275; and (4): 291-411; 2 plts. Li, C. CHanc 1930. The Miocene and Recent Mollusca of Panama Bay. Bull. Geol. Soc. China, Peking 9 (3): 249 - 279; plts. 1-8 ListER, MartTIN 1685. Historiae sive synopsis methodicae conchyliorum. Pelecypoda No. 3, pp. Proc. Linn. London, 466 pages of plates. [Neither the pages nor the plates, sometimes several to a page, are numbered in the original edition. The figures are numbered consecutively within each of several chapters. The U.S. National Museum copy of the first edition was autographed by Lister and presented to the Earl of Pembroke, and later owned by Deshayes and Dall. A second edition, published in 1770 by William Huddesford, Oxford, contains an index, but it is not consistently binomial. The several plates on each page have been given numbers, as well as retaining the original numbers of the figures. Plate 308 (not 304) has figure 141.] MELVILL, James Cosmo 1893. Descriptions of twenty-five new species of marine shells from Bombay collected by Alexander Abercrombie, Esq. Manchester Lit. & Philos. Soc. Mem. & Proc., Ser. 4, 7: 52 - 67; 1 plt. (reprinted in Journ.. Bombay Soc., 8: 234 - 245; plt. 1, fide Zool. Rec.) THE VELIGER Vol. 12; No. 1 MELVvILL, JAMES Cosmo & ALEXANDER ABERCROMBIE 1893. | The marine Mollusca of Bombay. Manchester Lit. & Philos. Soc. Mem. & Proc., Ser. 4, 7: 17-51 (reprint pages renumbered 1 - 35) Moore, Hitary Brooke 1931. The systematic value of a study of molluscan faeces. Proc. Malacol. Soc. London 19 (6): 281 - 289; plts. 31 - 33 Nickiés, Maurice 1950. Mollusques testacés marins de la céte occidentale d’Af- rique. Man. Ouest-Afr., 2: i-x+1-269; 459 text figs. Paris, Lechevalier Otproyp, Ipa SHEPARD 1924. The marine shells of the west coast of North America. Stanford Univ. Publ. Geol. Sci., 1: 1-247; plts 1-57 Otiver, W.R. B. 1923. Notes on New Zealand pelecypods. Soc. London 15: 179 - 188 Otsson, AXEL ADOLF 1961. Mollusks of the tropical eastern Pacific, particularly from the southern half of the Panamic-Pacific faunal province (Pan- ama to Peru). Panamic-Pacific Pelecypoda. Paleont. Res. Inst. Ithaca, N. Y, 574 pp.; 86 plts. (10 March 1961) PELSENEER, PAUL 1911. Les lamellibranches de lexpédition du Siboga. Partie anatomique. Siboga-Exped. 53 a: 1 - 121; 26 plts. Pitssry, HENry AUGUSTUS 1895. Catalogue of the marine mollusks of Japan with de- scriptions of new species and notes on others collected by Fred- erick Stearns. Privately printed, Frederick Stearns, Detroit, pp. i- viii+ 1-196; 11 plts. Reeve, Lovett Aucustus 1854. | Monograph of the genus Mactra. In: Conch. Icon. 8. Lovell Reeve, London. (consists of 21 numbered plates, with explanations and descriptions on unnumbered facing pages. At the bottom of each page of explanation is the month and year of pub- lication; all are March, April, or May 1854). Riwewoon, W. G. 1903. On the structure of the gills of the Lamellibranthia. Phil. Trans. Roy. Soc. London (B) 195: 147 - 284 Say, THOMAS 1822. An account of some marine shells of the United States. Journ. Acad. Nat. Sci. Phila. 2: 221-248, 257-276, and 302-325 SmirH, Epcar ALBERT 1914. A list of Australian Mactridae, with a description of a new species. Proc. Malacol. Soc. London 11 (2): 137 - 151 SouTHWELL, T. 1925. A monograph of the Tetraphyllidea with notes on re- lated cestodes. Liverpool School of Trop. Med. Memoir (n. ser.), no. 2, 368 pp. Sturany, RupoLF 1899. Lamellibranchiaten des Rothen Meeres. In Expedi- tion S. M. Schiff “Pola” in das Rothe Meer. Zool. Ergeb. 14: 1-41; plts. 1-7 1905. Beitrage zur Kenntnis der Molluskenfauna des Roten Meeres und des Golfes von Aden. Nachrichtsbl. d. deutsch. Malakozool. Gesellsch. 37 year: 132-146 Tate, RatpH 1889. Descriptions of some new species of marine Mollusca from South Australia and Victoria. Trans. Proc. & Reprt. Roy. Soc. South Australia 11: 60 - 66; pit. 11 Proc. Malacol. Vol. 12; No. 1 THE VELIGER TomLin, JoHN Reap LE BrocKToN 1924. Notes on some Mactridae. Journ. Conchol. London 17 (5): 134 - 136 (he notes that Reeve’s monograph on Mactra appeared before all names published by DesuHayEs in this group, including those attrib- uted to DEsHAYEs by REEVE) 1931. Raeta abercrombiei Metvitt. Journ. Conchol. Lon- don 19 (4): 111 Vokes, Harotp E. 1967. | Genera of the Bivalvia: a systematic and bibliographic catalogue. Bull. Amer. Paleont. 51 (232): 105 - 394 Woop, WILLIAM 1828. Supplement to the Index Testaceologicus or a catalogue of shells, British and foreign. London, W. Wood. 59 pp.; 8 plts. (consists of names, without authors, on the explanation of the plates; the names should be attributed to Woop unless an earlier source can be found.) Yokoyama, MataJIRo 1922. Fossils from the Upper Musashino of Kazusa and Shim- osa. Journ. Coll. Sci. Imp. Univ. Tokyo 44 (1): 1-200; pits. 1-17 YoncE, CHarLes MAurIcE 1948. Cleansing mechanism and the function of the fourth pallial aperture in Sprsula subtruncata (pA Costa) and Lut- raria lutraria (L.). Journ. Mar. Biol. Assoc. Plymouth 27: 585 - 596 Page 23 Page 24 THE VELIGER Vol. 12; No. 1 A New Species of Gastropod (Fissurellidae, Fissurisepta) from the Eastern North Pacific Ocean IAN McT. COWAN Faculty of Graduate Studies, The University of British Columbia, Vancouver 8, British Columbia, Canada (3 Text figures) Fissurisepta SEGUENZA, 1863, Is CUSTOMARILY regarded as a subgenus of the genus Puncturella. This designation has been based upon characteristics of the shell, and the living animal seems never to have been described. Recently the discovery of a single living specimen in a dredge haul from 470 fathoms off the west coast of British Columbia not only extends the known distribution of the subgenus into the eastern Pacific Ocean but also permits reexamina- tion of its systematic status on the basis of some soft-parts anatomy. The type species, Puncturella (Fissurisepta) papillosa SEGUENZA, 1863, is known only from the Miocene of Sicily and adjacent regions. A second species of the sub- genus, P (F}) rostrata SEGUENZA, 1863, was described from the same deposits. A third species of Miocene occurrence was described as P (F) retula Wooprina, 1928. His speci- mens were from Jamaica. At almost the same time the subgenus was discovered as a fossil it was found in the living fauna off Norway (JEFFREY, 1882) and described as Puncturella (Fissuri- septa) granulosa JEFFREY, 1882. Subsequent explorations have yielded specimens from several parts of the Atlantic. Thus P(E) acuminata Watson, 1833, was taken off North Culebra Island in the West Indies, and again off Yucatan and off Cumberland Island, Georgia. Specimens from the two last localities were described by Dati (1889) as Fissurisepta triangulata, a name now regarded as a syn- onym of P (F) acuminata (FarFanTE, 1947). This species was collected again off the Azores where it provided the source of yet another apparent synonym microphyma DAUTZENBERG & FiscHER, 1927 (FARFANTE, 1947). A second species from the West Atlantic off Georgia was named by Dati (1927) as Puncturella tenuicula. CiarKE (1962) has named a 5" species from the Atlantic as Puncturella (Fissurisepta) agulhasae. Fissurisepta was unknown in the Pacific until 1951 when Kuropa named and described the shell details of Punctu- rella (Fissurisepta) soyoae from Japanese waters. More recently OkuTANI (1964) has reported a second species, P. (F) undulata from the western Pacific Ocean. The bathymetric range of this creature, with one excep- tion, has extended from 200 fathoms down to 2507 fath- oms. The one exception is the Norwegian occurrence at 50 fathoms. The single specimen from the eastern Pacific appears to differ from other described species and is designated: Fissurisepta pacifica CowAN, spec. nov. Description of Holotype: Shell delicate, white with very thin straw coloured surface pigmentation, conical, with anterior slope slightly convex, and posterior slope slightly concave; foramen somewhat damaged but apparently al- most circular and situated slightly behind centre. Sculpture of small pustules widely spaced, nowhere closer to each other than 4 or 5 times their diameters (Figure 3) ; ar- ranged generally in horizontal rows around the shell, about 6 rows in the height of the shell. On the sides, pus- tules of adjacent rows arranged so that some diagonal order is apparent, sloping upward toward the anterior end. Interior of shell glossy white, septum thin, straight, transverse, extending obliquely downward at an angle of 20° from the anterior slope for about half the height of the shell; free margin semilunate. Dimensions of shell: length 5.1mm; width 3.85 mm; height 2.6mm. Subse- quent to the preparation of this description the specimen was broken in transit. The fragments remaining reveal details of surface sculpture but not overall shape, the fora- men nor the septum. Vol. 12; No. 1 The soft parts of the genus have not previously been described. The soft parts of the posterior segment of the body of our specimen are badly damaged but the portions avail- able for study include the head and the mantle cavity anterior to the heart. Figure 1 illustrates the general features of the head. From the ventral aspect the oral disk is wider than long. There are two pairs of cephalic tentacles, and in the preserved state the anterior pair is thick, blunt and turned down alongside the oral disk. The posterior pair is long and slender. There are no eyes. The most remarkable feature of the superficial anato- my is that of the ctenidia. Cox (1964, p. 194) states that all Recent species belonging to the suborder Pleurotomari- ina, with the single exception of the right ctenidium of Scissurellidae, have bipectinate ctenidia. Our specimen Figure 1 Fissurisepta pacifica Cowan, spec. nov. Ventro-lateral view of head end. has disproportionately large gills that occupy almost the entire anterior mantle chamber and both gills are mono- pectinate (Figure 2). The main axis of each ctenidium is external and it, as well as most of the length of each branchial filament, is fused with or adherent to the mantle. The posterior filaments are free for their terminal thirds. This is thus the only Pleurotomariine known to have symmetrically monopectinate ctenidia. Other distinctive anatomical features should be sought in any fresh speci- mens that become available. Type Material: A single known specimen number 6522, Cowan Collection, University of British Columbia, will be THE VELIGER Page 25 Figure 2 Fissurisepta pacifica Cowan, spec. nov. Dorsal view of anterior third, showing ctenidia as seen through transparent mantle. deposited in the type collection of the National Museum of Canada as N. M. C. Number 45744. Type Locality: West north west of Triangle Island, Brit- ish Columbia, 51°09’ N Latitude, 130°09’ W Longitude, haul number 63-214 of the Fisheries Research Board of Canada, Cowan station 863; 470 - 480 fathoms. Collected by D. B. Quayle, September 11, 1964. Discussion: Fissurisepta pacifica is generally similar in shell details to EF soyoae Kuropa as described and figured by him in 1951. It differs, however, in being relatively flatter, with the height about two thirds of the width rather than equal to it. It differs also in the number and arrangement of the tubercles on the shell, which in F soyoae are shown to be numerous and in well organized rows of closely placed studs arranged obliquely, whereas in FE pacifica they are widely separated, few in number and in generally horizontal rows. This must be a scarce species as just one specimen has been taken at about 30 stations below 200 fathoms worked by us in the past 3 years. Page 26 An examination of descriptions of other species hither- to assigned to this subgenus suggests that some detailed re- examination is necessary. The type species Fissurisepta papillosa SEGUENZA is known only as a fossil but our species subscribes to the shell details as does EF soyoae. Puncturella (Fissurisepta) Wooprinc, 1928 differs in such essential details of shell structure as thickness, height, external sculpture and in the size of the shelf. It may well be improperly assigned to Fissurisepta. The unique features of the ctenidia of Fissurisepta pa- cifica lead me to conclude that a separate generic desig- nation is necessary to recognize the degree of departure from the characteristics of representatives of Puncturella. Accordingly, on the assumption that the other species at- tributed to the subgenus Fissurisepta possess or possessed the same ctenidial structure, I suggest that Fissurisepta be accorded generic rank. Figure 3 Fissurisepta pacifica Cowan, spec. nov. Surface detail of holotype. The definition of the genus Fissurisepta can be stated: Prosobranch, Zeugobranch gastropods of small size with tall-conical shells in which the aperture is apical. The septum large, about half the height of the shell and pas- sing straight from side to side. External sculpture of the shell variable, consisting of either delicate vertical striae or of minute, widely separated studs in horizontal or oblique rows. Animal with 2 pairs of cephalic tentacles, the posterior long and slender, no eyes, ctenidia paired, symmetrical and monopectinate, attached for most of their length to the inner surface of the mantle. All but one of the living and fossil forms described have been taken from the northern oceans. There is, how- ever, a New Zealand Fissurellid, Puncturella manawata- whia Powe Lt, that, from published descriptions seems THE VELIGER Vol. 12; No. 1 closely similar. It would be interesting to study this species in more detail. ACKNOWLEDGMENTS Dr.James H. McLean, Los Angeles County Museum of Natural History assisted with the preliminary identifica- tion and provided the photographic figures; the anatom- ical figures are the work of Margaret Jensen. LITERATURE CITED CrarkE, ArTHUR H., Jr. 1961. Abyssal mollusks from the South Atlantic Ocean. Bull. Mus. Comp. Zool., Harvard, 125 (12): 345 - 387; 4 plts. Cox, Lestie REGINALD 1960. | Gastropoda/General characteristics of Gastropoda In: R.C. Moore, Treatise on invertebrate paleontology Prt. I, vol. 1: 84 - 169; figs. 51 - 88E Dati, WiLL1AM HEALEY 1889. Reports on the results of dredging, . . . in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U. S. Coast Survey Steamer “Blake”, . . . Report on the Mollusca, pt. 2, Gastropoda and Scaphopoda. Bull. Mus. Comp. Zool. 18 (2) : 1 - 492; plts. 1 - 40 1927. Small shells from dredgings off the southeast coast of the United States by the United States Fisheries Steamer “Albatross” in 1885 and 1886. Proc. U. S. Nat. Mus. 70: 1- 134 DAUTZENBERG, PHILIPPE & HENRI FISCHER 1927. Résultats comparat. scientif: accomplies sur son yacht par Albert 1** de Monaco. 77: 224; plt. 7, fig. 16 FaRFANTE, ISABEL PEREZ 1947. The genera Zeidora, Nesta, Emarginula, Rimula, and Puncturella in the Western Atlantic. Johnsonia 2 (24): 93 - 148 JEFFREYS, JOHN Gwyn 1882. On Mollusca procured during the “Lightning” and “Porcupine” expeditions, 1867-70 (Part V). Proc. Zool. Soc. London for 1882: 656 - 687; 2 plts. Kuropa, ToKuUBEI 1951. _— Illustrated catalogue of Japanese shells. No. 17: Fissur- ellidae, p. 116 OKUTANI, TAKASHI 1964. | Report on the archibenthal and abyssal gastropod Mol- lusca mainly collected from Sagami Bay and adjacent waters by the R. V. Soyo-Maru during the years 1955 - 1963. Journ. Fac. Sci., Univ. Tokyo, Sec. II, 15 (3): 371 - 447 PowELL, ARTHUR WILLIAM BADEN 1937. | New species of marine mollusca from New Zealand. Discovery Reprts. 15: 153 - 222; 11 plts. SEGUENZzA, G. 1863. Paleontologia malacologia dei terreni Terziarii del dis- tretto dei Messina ... Fanuglia Fissurellidi. Amali Accad. Aspir. Naturalisti, Naples, ser. 3, 2: 83 - 86 Wooprinc, WENDELL PHILLIPS 1928. Miocene mollusks from Bowden, Jamaica. Part 2: Gas- tropods and discussion of results. Carnegie Inst. Washington, Publ. 385: i- vii + 1-564; 3 text figs.; plts. 1-40 (28 Nov.) peng Vol. 12; No. 1 THE VELIGER Page 27 Seasonal Gonadal Changes of Adult Oviparous Oysters in Tomales Bay, California BY CARL J. BERG, Jr. Pacific Marine Station, Dillon Beach, California ':? (Plates 1 to 3; 1 Text figure) INTRODUCTION Two SPECIES OF oviparous oysters, Crassostrea virginica (GmetIn, 1791), the Eastern oyster, and Crassostrea gigas (THUNBERG, 1793), the Japanese oyster, were intro- duced into Tomales Bay, California for commercial pur- poses. Because these oysters do not reproduce in its waters, shipments of adult oysters or oyster spat must be period- ically transplanted into this bay. It is the purpose of this study to compare the seasonal gonadal changes which occur in the two species of adult oysters in Tomales Bay with one another, and to compare them with similar changes occurring in the same species of oysters in other regions. The differences in gonadal changes will be related to variations in environmental conditions and to specific or racial characteristics. Tomales Bay is located on the Northern Californian Coast, approximately 40 miles north of San Francisco. The oysters used in this study were kept at Tomales Bay Oyster Company, which is situated in the cove between Millerton and North Double Point, near the headwaters of the bay. This area has long been the site of oyster culture. The native or Olympia oyster (Ostrea lurida CarPENTER, 1864) was the first oyster species grown in Tomales Bay to be shipped to the markets of San Fran- cisco. However, upon completion of the transcontinental Central Pacific Railroad in May 1869, it was possible for the first time to ship live adult Crassostrea virginica and its seed to the Pacific coast. In 1875, 17 carloads of C. virginica were laid out near Millerton Station in Tomales Bay (TownsEnp, 1893). Cultivation of C. virginica in Tomales Bay has continued intermittently since that time. ‘ Submitted in partial fulfilment of the requirements for the Degree of Master of Science in Marine Science at the University of the Pacific, Stockton, California. 2 Present address: Department of Zoology, University of Hawaii, Honolulu, Hawaii 96822 The tidelands of Tomales Bay Ovster Company were also the first areas in California to be used for the culture of Japanese oysters (C. gigas), which were introduced into Puget Sound in 1902, and later, in 1928, into Tomales Bay (BarreTT, 1963). Both C. virginica and C. gigas have failed to reproduce in Tomales Bay and continued impor- tation of adult oysters or seed has been necessary. Because of their commercial value, there have been numerous attempts at the artificial introduction of oysters into areas lacking natural populations, or in which the native oyster is of little economic importance. The oysters of the genus Crassostrea Sacco, 1897, are more often used as introduced species than are those of the genus Ostrea LINNAEUS, 1758, since they have a greater ability to survive in extreme and varying environments. Cyrass- ostrea virginica has been introduced into the oyster beds of Britain, the Pacific Coast of North America, and the island of Oahu, Hawaii. Crassostrea gigas has likewise been introduced into the oyster beds of the Pacific Coast of North America; Oahu, Hawaii; also into Melbourne Harbour, Australia; Mobile Bay, Alabama; and Barnstable Bay, Massachusetts. The Portuguese oyster, C’. angulata (Lamarck, 1819) has taken over all of the French oyster beds and now also lives, but does not reproduce, in British beds. One noteworthy and successful introduction of oysters of the genus Ostrea took place in the waters of Boothbay Harbor, Maine, where LoosANorF (1955) had transplanted European oysters (Ostrea edulis LINNAEUS, 1758) in 1949. In many of the attempts to introduce a specics of oyster to a new location, the animals may have survived and grown well, but failed to reproduce. To determine the reason for the failure of the species to reproduce, one must be familiar with the seasonal gonadal changes which occur in the oysters in their native environment. There have been studies on gonadal changes in each of the commercially valuable species of oysters. Crassostrea Page 28 virginica is the most extensively studied species of the oviparous oysters (Hopkins, 1931; Loosanorr, 1932, 1942, 1965; LoosaNorF & ENGLE, 1942; BuTLER, 1949; KENNEDY & BATTLE, 1964; SEVILLA & Monpracon, 1965). Crassostrea gigas has had little work done on its gametic activity (Imai et al., 1950; Imar & Sax1, 1961) and the same is true with the other oviparous oysters: C. commer- cialis (IREDALE & RouGHLEy, 1933) (RouGHLEy, 1933; Cieanp, 1947); C. angulata (BARcETON, 1942, 1943) ; and C. madrasensis (PRESTON) (ANOoNYMouS, 1950). Studies have also been made of gonadal changes in the larviparous oysters: Ostrea edulis (Orton, 1927, 1931, 1933; Core, 1942) and O. lurida (Cor, 1931, 1932). Even less work has been done on the seasonal gonadal changes in oysters which have been introduced into new areas. LoosanoFF (1962a) gave a detailed description of the changes which occurred in the gonads of O. edulis introduced into Boothbay Harbor, and briefly mentioned the gonadal changes which occurred in C. gigas trans- planted into Milford Harbor (LoosanorF & Davis, 1963). Ga.tsorF (1929) and KaTKaNSky & SPARKS (1966) discussed the gonadal changes and sex ratios which oc- curred in C. gigas cultured in the waters of the State of Washington, and Evsey (1932, 1933, 1934) described the changes in C. gigas in the waters of British Columbia. Ostrea lurida is the only other species in which the sea- sonal gonadal changes have been thoroughly studied in both the native environment (Cog, 1931, 1932) and in the area to which it was introduced (Hort, 1933). The introduction of oysters into a new environment is valuable for both scientific and commercial reasons. Al- though it has long been known that Crassostrea virginica and C’.. gigas do not reproduce in Tomales Bay, no one has ever done a detailed study of the reproductive cycle or the seasonal histological changes in the gonads. This study, therefore, extends the knowledge concerning an oyster’s adaptation to its new environment and may help to define the reasons for the failure of these two species of oysters to reproduce in Tomales Bay. MATERIALS ann METHODS The oysters used in this study were obtained from Long Island Sound and from Canadian waters through the courtesy of the Department of Fish and Game of the State of California, Dr. Victor L. Loosanoff and Dr. Ed- mund H. Smith of the Pacific Marine Station. Four hund- red and fifty 2-year old Crassostrea gigas of Canadian ori- gin were taken from the mud-flats at Tomales Bay Oyster Company where they had been raised. They were then placed in wire-mesh trays and suspended from racks at THE VELIGER Vol. 12; No. 1 the Oyster Company on October 20, 1966. A similar number of 2-year old C. virginica was received on Octo- ber 26, 1966, and was placed in identical adjacent trays. Fifteen oysters of each species were collected at bi-weekly intervals for 15 months. An additional sample of 13 C. virginica was obtained on October 5, 1966, from a stock which had been previously kept at Tomales Bay Oyster Company. The height (distance between the umbo and the ventral valve margin) and length (distance between anterior and posterior valve margins) of each oyster were measured with calipers before the oyster was opened. A tissue sample was taken from the gonadal area near the labial palps in conformity with the practice of the biological labora- tories of the United States Bureau of Commercial Fish- eries. This gonadal tissue was fixed in Bouin’s solution, infiltrated with 52.5° C paraffin, sectioned at 10 B, and stained with Heidenhain’s iron hematoxylin and aqueous eosin Y, using standard procedures. The tissues were then microscopically analysed for sex and state of gametogen- esis. Hydrographic data were collected on each sampling date; they included measurements of salinity, hydrogen- ion concentration, and turbidity of water samples taken one foot above the bottom by means of a Frautschy-bottle sampling device. Sub-surface water temperatures were taken by suspending a thermometer over the bottom. Surface-water hydrographic data were obtained from rec- ords kept at the Pacific Marine Station. Large bags of sun-bleached oyster shells were suspended near the trays of oysters for 2-week periods from May 4, 1967 until October 19, 1967. Fifty shells were chosen at random from each bag and examined for oyster spat. During the same period plankton tows were taken over the beds of Tomales Bay Oyster Company and examined for bivalve larvae. All oyster larvae were identified by length-width measurements after the method of Loosan- oFF, Davis & CHANLEY, 1966. OBSERVATIONS A detailed description of the sequence of events in the development of functional gametes has been given by LoosanoFF (1942) for Crassostrea virginica. Since the seasonal gonadal changes observed in both C. virginica and C. gigas in Tomales Bay differed little from those described, except with regard to timing (LoOOSANOFF & EncLE, 1940; Loosanorr, 1965), only a résumé of the gonadal changes will be given here. It is most convenient to describe the seasonal gonadal changes which occurred Vol. 12; No. 1 THE VELIGER Page 29 Salinity %, Temperature in ° C Co) ONDJFMAMJJAS ON D Month Figure 1 Water temperature and salinity at Tomales Bay Oyster Company from October 1966 to December 1967 in the two species separately and in the order in which they were observed. Specimens of Crassostrea virginica were obtained from Tomales Bay Oyster Company on October 5, 1966, where they had been kept for at least a year. The small gonadal follicles of these oysters contained only indifferent sex cells and were scattered in the large masses of connective tissue. This “indifferent stage” (LoosanorrF, 1942, p. 203) was characteristic in the months of September, October, and November of 1967. Page 30 The remaining samples of gonadal tissue were collected from Crassostrea virginica transplanted into Tomales Bay Oyster Company beds on October 26, 1966. Slight ga- metic activity ended the indifferent stage of some of the oysters during the months of November and December. Primary and secondary gametogonia started to develop along the follicular walls, making sex determination pos- sible. The follicles began to expand gradually. A marked increase in the size of the follicles and in the acceleration of maturation of the gametes was no- ticed in late December and January. Ovocytes began to fill the follicles and spermatids were already devel- oping. The follicles showed rapid growth and ramification. Continued maturation of the gametes took place in February and March, concurrently with the disappearance of the voluminous vesicular connective tissue. In some instances, mature ova and spermatozoa were present. By the sixth of April, most of the gonads were packed with ripe gametes, some of which nearly filled the ciliated genital ducts (Plate 1, Figures 1 and 2). However, a few cells at the earlier stages of gametogenesis were pres- ent on the follicular walls. This state of maximum ripe- ness was maintained throughout the spring. Although a few oysters were partially spawned beginning at the middle of April, mass spawning did not occur until the © middle of June and continued until the middle of July. On July 13, 87% of the sample was completely spawned. This coincided with the time of greatest rate of increase in water temperature (Text figure 1). The gonads of spawned oysters were characterized by the absence of mature gametes and the shrunken appear- ance of the follicles (Plate 1, Figures 3 and 4). Great numbers of phagocytic cells were present, both inside the lumina of the follicles and around the outside walls. All unshed gametes are devoured by these cells. The lumina of the follicles were being closed by elongation and the shrinking of follicular tissue. Simultaneously, the cells of THE VELIGER Vol. 12; No. 1 the vesicular connective tissue proliferated, filling all inter- follicular spaces. Resorption of gametes continued from the post-spawning stages in July until the first week of November, and a few follicles were observed to contain mature gametes being phagocytized as late as December. However, most gonads were in the indifferent stage by September. All samples of gonadal tissue from Crassostrea gigas were collected from oysters which had been raised in Tomales Bay from the imported seed. Although the sea- sonal gonadal changes which were observed in C. gigas resembled those of C. virginica, there were differences between species in timing and in the homogeneity of the sample. The indifferent stage of gametogenesis was char- acteristic of the months of November and December. The little gametic development and proliferation of the follicles which occurred in December and January is the only activity which might be characterised as the “sex- differentiation stage” (Loosanorr, 1942, p. 203). Very rapid maturation of the gametes took place in January and February, with a great expansion of the follicles. March was the month of greatest maturation and proliferation. By the eleventh of March, ripe ova and spermatozoa were present in a few of the follicles. From April 6 until July 27, 95% of all the gonads sampled were filled with ripe gametes (Plate 2, Figures 5 and 6). They retained gametes throughout the spring, however, because no spawning took place until after the twenty-seventh of July. Between the dates of July 27 and August 10, mass spawning of Crassostrea gigas occurred. This coincided with the warmest water temperatures to that date (Text figure 1). Again, the follicles of the spawned gonads were shrunken and devoid of ripe gam- etes (Plate 2, Figures 7 and 8). Resorption and cytolysis of the unshed gametes started immediately after spawning was completed and con- Explanation of Plate 1 Figure 1: Section of gonad of ripe female Crassostrea virginica collected April 6, 1967 (X 125) Figure 2: Section of gonad of ripe male Crassostrea virginica collected April 6, 1967 (X 125) Figure 3: Section of gonad of spawned female Crassostrea virginica collected July 13, 1967 (X 125) Figure 4: Section of gonad of spawned male Crassostrea virginica collected July 13, 1967 (X 125) Explanation of Plate 2 Figure 5: Section of gonad of ripe female Crassostrea gigas collected April 6, 1967 (X 125) Figure 6: Section of gonad of ripe male Crassostrea gigas collected April 6, 1967 (X 125) Figure 7: Section of gonad of spawned female Crassostrea gigas with a few ova remaining in gonad tubules. collected August 10, 1967 (X 125) Figure 8: Section of gonad of spawned male Crassostrea gigas showing spermatozoa remaining in gonad tubules. collected August 10, 1967 (X 125) [BERG] Plate 1 Tue VELIGER, Vol. 12, No. 1 | ' } i t é ah U SA ¢ i a 4 i n Ara = Cat re i 4 i i , a v 7 4 ° - Cah Tue VELIGER, Vol. 12, No. 1 [Berc] Plate 2 ee mY baal j » Y Ad me a ~ Se ee Figure 5 Fy , ¥ eo 2 ‘ es, «* tet oe | 7 y , ms Rey : s ke . 2 5 4 , «4 , 2 ; ; 3 » » ty ‘ ; .* ; , : > . : ¥ Figure 8 Vol. 12; No. 1 tinued until December. Many spermatozoa and ova were found being phagocytized, some until late December. In addition to observing the gonadal changes, the sex ratio was also noted. Frequently, however, the sex could not be determined since the gametes were not yet differ- entiated. In a sample of 387 Crassostrea virginica, 139 were male, 114 were female, and 132 were undifferenti- ated. Two morphological hermaphrodites were found. Both contained follicles packed with spermatozoa and a few cytolized ova (Plate 3, Figure 9). In a sample of 382 C. gigas 100 were male, 194 were female, and 87 were undifferentiated. Only one hermaphrodite was found for this species. Unlike those observed in the sample of C. virginica, the follicles of the hermaphroditic C. gigas con- tained both male and female gametes in various stages of development (Plate 3, Figure 10). The hydrographic conditions observed in the bay are presented in graphic form (Text figure 1). The range of hydrogen-ion concentration was not great enough (7.70 to 8.16) to affect gonadal changes, neither did it exhibit seasonal variances. Hence, these data are not presented in this article. The turbidity determinations are not presented either, although the turbidity of the water showed distinct seasonal variations. Both temperature and salinity may affect gametogenesis (KINNE, 1963, 1964; LoosaNnorr, 1945, 1948). Text figure 1 presents temperature and sa- linity data in graphic form so that seasonal irends may be more apparent. The difference between surface and bottom salinity samples is significant and noteworthy since the oysters were exposed to surface water at low tides. The extreme range in salinities is due to the effect of fresh-water runoff during the winter and spring, and to evaporation during the summer. Salinities in excess of 32%, prevailed from July to December. Throughout the winter and spring, however, the salinity remained around 25%. The water temperature at the oyster beds exhibited similar seasonal fluctuations. A trend of rising tempera- tures starts in January after a brief cold period and con- tinues until June. The water temperature remains close to 20°C during June, July, August and September. The water then begins to cool to its lowest temperature at the end of the year. Rarely did the temperature remain below 10°C for more than a few days, neither did it range much above 20° C. All hydrographic observations, including temperature determinations, were made at approximately mid-tide. More extreme temperatures may exist during slack tides, but thermograph records for that area showed that the water temperatures remain markedly constant throughout the tidal cycle. Finally, few Crassostrea larvae were collected by the plankton tows and few spat were found on shells. Some THE VELIGER Page 31 straight-hinge stage larvae were found in the plankton samples of August 24 which had general appearances and dimensions similar to those reported for C. virginica and C. gigas (LoosanorF, Davis & CHANLEY, 1966). Although bivalve larvae were collected in every sample, no others approximated the proper size or shape. A total of 6 oyster spat was found set on shells; one on July 13, and 5 on August 10. Three of those found on August 10 had settled on the inside of the right valve of an oyster which was gaping. The inside of the shell was free of mud, although the outside was covered. Through- out the summer, all shells in the wire-mesh bags were found to be covered with mud after 2 weeks in the water. It is surprising that any larvae were able to set on such shells. DISCUSSION Gametogenesis and spawning of oysters are directly cor- related to water temperatures. LoosanorF & Davis in 1952 have shown the temperature and time requirements to condition Crassostrea virginica to spawn. Their experi- ments showed that 10° C was not high enough to induce gametic activitics. However, they report ripening and spawning for oysters when the temperature had reached only 15°C. Later experiments (Loosanorr, 1958, 1969) proved that maturation of gametes was possible after 68 days of conditioning at 12° C. The water temperatures at Tomales Bay Oyster Company remained above 12°C throughout the year, except for short periods of time in December and January. During the summer, the water temperature was not as high as those reported for either Long Island Sound or the Miyagi Prefecture, Japan, from where the oysters originally came. The differences in seasonal temperature fluctuations between Tomales Bay and the native environments of the oysters were respon- sible for the variances in gonadal changes (Table 1). Low salinities which may have an influence on gonad development (LoosanorFr, 1948; 1952), were not en- countered for extended periods of time, thus they did not seem to affect gonadal changes in oysters in Tomales Bay. A comparison of seasonal gonadal changes between Crassostrea virginica and C. gigas must take into account differences between the species and racial variations within each species. As mentioned previously, the seasonal gonadal changes observed in both C. virginica and C. gigas differed little from each other, except for timing. The differences in timing are clearly portrayed in Table 1. The only time of agreement in stages of gametogenesis was from the first week in April, when approximately 757% of the samples from both species contained ripe ova and Page 32 THE VELIGER Vol. 12; No. 1 Table 1 Periods of Basic Gonadal Stages in Crassostrea virginica and Crassostrea gigas in Different Geographic Areas. Crassostrea virginica Stage Tomales Bay Long Island California Sound Spring January Development and and February May Crassostrea gigas Tomales Bay State of Miyagi Prefecture, California Washington Japan February May and — March June First April June April May May Ripening ‘ Spawning through August From Post- From Post- Resorption Spawning to Spawning to October October Undiffer- September August entiated through and November September Fall November October Gametogenesis and and December November December Inactive None to April sperm, until the end of June when most of C. virginica had spawned. During this period, no C. gigas spawned, but a few of C’. virginica had partially spawned and some were undergoing resorption. Mass spawning of C. virgini- ca was completed at least two weeks before C. gigas spawned, and it extended over a greater period of time than did the 2-week mass spawning of C. gigas. Since the shed gametes of both species can induce spawning in the males of either species (GaLTSoFF, 1964), it is sur- prising that C. gigas did not spawn simultaneously with C. virginica. A combination of thermal and chemical re- quirements is often needed to induce spawning. These requirements were obviously not met for C. gigas until a later date. Not all of the oysters of either species had spawned completely. More of Crassostrea gigas contained ripe ova and spermatozoa, and retained them until later dates, than did C. virginica. Resorption of unshed gametes con- tinued into December for C’. gigas. During and following resorption, the gonadal follicles were in the undifferenti- ated stage. This stage was halted with the advent of gametogenesis. In C. virginica, gametogenesis started in November, one month earlier than in C. gigas. Matura- tion proceeded gradually until after the first of the year for both species. In late December, January, and February, July July August and and and August September From Post- Spawning to — December From Post- Spawning to December October through November and December December February through April the gametes of C. virginica showed a great acceleration in maturation. This acceleration, termed “spring develop- ment” by LoosanorF (1942, p. 198), again occurred one month earlier in C. virginica than in C. gigas. However, C. gigas showed a greater burst of gametic activity in March. Thus, both species reached sexual maturity at the same time. In general, C. gigas has a higher temperature requirement for the initiation of both gametogenesis and spawning. This is evident by the slower development and later spawning dates. Moreover, unshed gametes are re- tained by C. gigas for longer periods of time before being resorbed. Similar differences were observed between C. virginica and C. gigas transplanted into Milford Harbor (LoosanorF & Davis, 1963). A series of observations on seasonal gonadal changes of two other bivalve species was conducted concurrently with this study (LEonarD, 1969). Ostrea edulis, trans- planted into Tomales Bay Oyster Company beds, and Pododesmus cepio (Gray, 1850), the native rock jingle, both showed gonadal changes at dates which correspond well with those observed for Crassostrea virginica and C. gigas and with the seasonal fluctuations in temperature. A comparison of the timing of the gonadal changes of Crassostrea virginica in Tomales Bay with those reported for it in Long Island Sound (Loosanorr, 1942; 1965) Vol. 12; No. 1 emphasizes tiie effect of temperature upon gametogen- esis and spawning (Table 1). Spawning occurred in both locations at the end of June when the water temperature was about 20° C. Post-spawning resorption continues into October in both locations, but the undifferentiated stage is being completed in Long Island Sound in September, and not until November in Tomales Bay. Fall gametogenesis extends from October to December in Long Island Sound but occurs one month later in Tomales Bay. Whereas Long Island Sound oysters exhibit no gametic activity from December until April or May, oysters in Tomales Bay proceeded to carry out gameto- genesis through the winter, with the period of fastest ma- turation occurring in February. In April, when oysters in Tomales Bay were already ripe, Long Island Sound oysters were developing only primary and secondary gametocytes. During the entire spring, oysters in Tomales Bay contain ripe gametes, while the gametes in Long Island Sound oysters are just maturing. In both areas, the gametes are ripe in June. To reiterate, the major difference in gonadal changes between Crassostrea virginica in Long Island Sound and those transplanted into Tomales Bay is that the follicles of the latter do not exhibit an inactive stage; rather they continue to develop from November until they are mature in April. The ripe gametes then remain in the follicles until spawning occurs. This is probably due to differences in winter temperatures of the two areas. There is little information on the seasonal gonadal changes of Crassostrea gigas. Although a few authors mention the temperature at which spawning occurred, none describe the histological changes taking place in the gonads prior to spawning. Spawning is recorded for temperatures below 20°C (Fuyrra, 1929; Hopxins, 1936; ScHarFEeR, 1938; CuHapMaN & EsvetpT, 1943), which is well within the range encountered in Tomales Bay. Imar & Saki (1961) report that spawning takes place in Miyagi strains of C. gigas late in August and early in September, although the gonads were ripe as early as May. Amemiya (1928), however, reports that spawning of northern province Japanese oysters may take place in May and June. The timing of gametogenesis and spawning of C. gigas in Tomales Bay best corresponds with the data from Imari & SAKI (op. cit.) but seems to be one month ahead at all stages. Crassostrea gigas raised in the State of Washington also exhibit gonadal changes and spawning at tempera- tures almost identical with those observed in Tomales Bay. Spawning is reported to occur during the last part of July and the first part of August when the water tempera- tures ranged between 18° C and 20°C (Scuaerer, 1938; CHAPMAN & EsveLpT, 1943). This coincides perfectly THE VELIGER Page 33 with the observations of spawning in Tomales Bay. In the follicles of C. gigas in Washington waters, resorption of the unshed gametes continues through December (Ga.tsorF, 1929). The follicles begin to proliferate in December and January (KaTansky & Sparks, 1966), but then gametic activity appears to be arrested. Re- sumption of maturation of the gametes takes place in April or May, with ripe ova and active sperm again present by May (GaLTsorr, op. cit.; CHAPMAN & Es- VELDT, op. cit.). The inactive wintering stage is similar to that of C. virginica in Long Island Sound. As mentioned previously, C. gigas in Tomales Bay does not become in- active; rather the gametes mature most during the months of January, February, and March. It is apparent that Crassostrea gigas in Tomales Bay meets with seasonal temperature fluctuations which are similar to those in the State of Washington, where they were first introduced. Normal gametogenesis and spawn- ing occurs in all three areas. Only in Japan, however, is the combination of all environmental factors consistently suitable for the setting of oyster larvae. Some setting of commercial value also occurs occasionally in Washington and Canadian waters. In fact, the oysters used in this study were from Canadian seed. There have been no reports of a large set of either C. gigas or C. virginica in Tomales Bay, although one naturally set C. gigas was found. Factors other than temperature, salinity, and hy- drogen-ion concentration are probably involved, since these factors correspond well with those found in the oyster’s native environment. Excessive turbidities were noticed throughout the summer. These probably had a deleterious effect upon both the larvae and the places available for setting. A more complete discussion of the effect of the environment upon the larvae will be pre- sented at a later date. LoosaNnoFF (1962b) has shown the effect of turbidity upon oyster larvae, and LoosANoFF & ToMMERS (1948) have suggested that there exist races of C. virginica which exhibit different abilities to survive high turbidi- ties. Furthermore, races based upon the oysters’ adapt- abilities to an environment, shell characters, and temper- ature requirements for breeding have been described for both C. virginica and C. gigas (STauBER, 1950; LoosANOFF & NoMEjKo, 1951; Imar & Saxt, 1961; Loosanorr, 1969). Oysters from northern latitudes have been shown by these authors to have a much lower temperature requirement for the development of gametes and the induction of spawning. The results of this study showed great differ- ences within the population of C. virginica dredged from Long Island Sound and transplanted into Tomales Bay. In any one sample, the oyster gonads would show a continuum through two or three stages of development. Page 34 Some oysters ripened and spawned much earlier than most; others much later. In addition, resorption of unshed gametes proceeded at greatly varying rates. Some oysters contained ripe ova and spermatozoa even in December. The population of C. gigas did not show as great variance, probably because the oysters were collected as seed from a small area and then transplanted into Tomales Bay. The greater homogeneity of the population indicates that only one race was observed. Some individual differences were noted, but this should be expected. ‘The oysters used in this study came from the northern limits of the distri- bution of each species. If more southern oysters were used, the environmental conditions in Tomales Bay would not have favored spawning. In all attempts at intro- ducing a species into a new area, consideration must be given to the racial characteristics of the oysters. Animals with the lowest temperature requirements are best suited for such experiments. Recent findings support the earlier observations that crowded conditions of oysters might favor the develop- ment of one sex or the other. In crowded conditions, Crassostrea virginica are reported to show a population trend toward the male phase (BuRKENROAD, 1931; NEED- LER, 1934) and C’. gigas to the female phase (KATANSKY & SPARKS, 1966). However, experimental evidence (V. L. LoosanorF, MS) has shown that crowded conditions did not affect sex determination in adult C. virginica. The samples taken for this study indicate that a female phase may be favored by C. gigas in crowded conditions, but that C. virginica showed approximately equal sex ratios. The number of hermaphrodites found is also within the normal range. (Gattsorr, 1964). In Crassostrea gigas 0.26% were hermaphrodites (1 out of 382) and in C. virginica 0.52% (2 out of 387). The few ova present in the ripe male follicles of C. virginica were cytolized (Plate 3, Figure 9), but both the ova and the spermatozoa in C. gigas appeared normal (Plate 3, Figure 10), with primary and secondary spermatocytes present. Therefore, the hermaphrodites observed in C.. virginica would best be called morphological, but the one C. gigas was probably a functional hermaphrodite. All of the hermaphrodites were collected in the spring during the period of greatest gametic activity. It is unlikely, therefore, that the gametes had been carried over from the previous season. A few major conclusions have been drawn from this study of the seasonal gonadal changes in Crassostrea THE VELIGER Vol. 12; No. 1 virginica and C’. gigas introduced into Tomales Bay, Cali- fornia. Differences in the gonadal changes between in- dividuals of each species, between two species, and between the oysters in Tomales Bay and those of the same species in their native environment are attributed to individual, racial, specific, and environmental variations. The sample of C. gigas was racially more homogeneous than that of C. virginica, and it required warmer temper- atures to initiate gametogenesis and spawning. During the annual cycle, one continuous period of gametic activity took place in both species. There was no inactive stage as is usually found in most species of Crassostrea in their native environments, because the water temperatures at Tomales Bay Oyster Company were favorable enough throughout the year to encourage gametogenesis and growth. The inability of the two species to propagate in Tomales Bay is not due to a failure to spawn, but rather to a failure of the larvae to reach the settled spat stage. ACKNOWLEDGMENTS I wish to thank Dr. Victor L. Loosanoff for the invaluable guidance and encouragement he gave me throughout the course of this study. My thanks are also extended to Dr. Edmund H. Smith, Dr. John S. Tucker, and Dr. Walter Narchi for their helpful advice and assistance. LITERATURE CITED Amemiya, IKUSAKU 1928. Ecological studies of Japanese oysters, with special ref- erence to the salinity of their habitats. Journ. Coll. Agr., Imp. Univ. Tokyo 9 (5): 333 - 382; 5 plts.; 3 text figs. ANONYMOUS 1950. Marine fisheries of India. Mollusca - Oysters and clams. Proc. Indo-Pacific Fish. Conf: Singapore 1949: 78 BarcETON, MarIzE 1942. Les variations saisoniéres du tissue conjonctif vesiculeux de l’huitre. Bull. Biol. France et Belg. 76 (2): 175-191; 6 text figs. 1943. | Modifications histologiques de la zone des gonades aprés la ponte chez Gryphaea angulata Lamx. Bull. Biol. France et Belg. 77: 97 - 103 Barrett, ELINoRE M. > 1963. The California oyster industry. Calif. Dept. Fish & Game, Fish Bull. 123: 103 pp.; 32 text figs. Explanation of Plate 3 Figure g: Section of gonad of a hermaphroditic Crassostrea vir- ginica containing both spermatozoa and cytolized ova. collected May 18, 1967 (X 125) Figure 10: Section of gonad of a hermaphroditic Crassostrea gigas containing both spermatozoa and ova collected April 6, 1967 (X 125) TuHeE VELIcER, Vol. 12, No. 1 [Bers] Plate 3 Figure 10 i a we = _ i" ae 7, UP an : 7 i = = , < > 4+ - ‘ t a ¥ * _ i = = = i = f 2, / J : ~ 7 : Vol. 12; No. 1 THE VELIGER Page 35 BuRKENROAD, Martin D. 1931. Sex in the Louisiana oyster, Ostrea virginica. Sci- ence 74 (1907) : 71-72 But er, Puiuir A. 1949. | Gametogenesis in the oyster under conditions of depressed salinity. Biol. Bull. 96 (3) : 263 - 269; 3 text figs. CHAPMAN, WILBERT McLeop « GrorcEe D. EsvELDT 1943. The spawning and setting of the Pacific oyster (Ostrea gigas THUNBERG) in the State of Washington in 1942. _ Biol. Rept. Dept. Fish., State of Washington No. 43A: 1-61; 7 text figs.; 13 tables. CLELAND, K. 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In: Oceanography and Marine Biology, H. Barnes (ed.), vol. 2. Hafner, New York; pp. 281 - 340; 17 text figs.; 14 tables LEonarD, VERNON KENNETH, Jr. 1969. Seasonal gonadal changes in two bivalve mollusks in Tomales Bay, California. The Veliger 11 (4): 382-390; plts. 58 - 60; 4 text figs.; 1 map (1 April 1969) Loosanorr, Victor Lyon 1932. | Observations on propagation of oysters in James and Corrotomon Rivers and the seaside of Virginia. Publ. Va. Comm. Fish. 46 pp.; 17 text figs. 1942. Seasonal gonadal changes in the adult oysters, Ostrea virginica, of Long Island Sound. Biol. Bull. 82 (2): 195 to 206; plts. 1-3; 12 text figs. 1945. Precocious gonad development in oysters induced in midwinter by high temperature. Science 102 (2640) : 124 - 125 1948. | Gonad development and spawning of oysters (O. vir- ginica) in low salinities. Anat. Rec. 101 (4) : 55 1952. Behavior of oysters in water of low salinities. Proc. Natl. Shellfish Assoc. 43: 135-151; 7 tables 1955. The European oyster in American waters. Sci. 121 (3135): 119-121 1958. Challenging problems in shellfish biology. In: Per- spectives in marine biology, Part ITV (1956), A. A. Buzzattt- Traverso (Ed.), Univ. Calif: Press, Berkeley & Los Angeles, pp. 483 - 495 1962a. Gametogenesis and spawning of the European oyster, Ostrea edulis, in waters of Maine. Biol. Bull. 122 (1): 86 - 94; 15 text figs. 1962b. Effects of turbidity on some larval and adult bivalves. Proc. Gulf and Carib. Fish. Inst. 14t Ann. Sess., 80 - 95; 2 tab. 9 text figs. 1965. | Gonad development and discharge of spawn in oysters of Long Island Sound. Biol. Bull. 129 (3): 546-561; 6 text figs.; 3 tables 1969. Maturation of gonads of oysters, Crassostrea virginica, of different geographical areas subjected to relatively low tem- peratures. The Veliger 11 (3): 153 - 163; plts. 19 - 25 (1 January 1969) LoosanoFF, Victor Lyon « Harry Cari Davis 1952. Temperature requirements for maturation of gonads of northern oysters. Biol. Bull. 103 (1): 80-96; 14 text figs. 5 tables Page 36 Loosanorr, Victor Lyon « Harry Cart Davis, continued 1963. Rearing of bivalve mollusks. Jn Advances in marine biology, vol. 1, FS. Russell (ed.). Academic Press, London, pp. 1-136; 43 text figs. Loosanorr, Victor Lyon, Harry Cart Davis & Paut E. CHANLEY 1966. Dimensions and shapes of larvae of some marine mollusks. Malacologia 4 (2): 351 - 435; 61 text figs. Loosanorr, Victor Lyon & JAMEs B. ENGLE 1940. Spawning and setting of oysters in Long Island Sound in 1937, and discussion of the method for predicting the in- tensity and time of oyster setting. Bull. U.S. Bur. Fish. 49: 217 - 255; 11 text figs.; 18 tables 1942a. Accumulation and discharge of spawn by oysters living at different depths. Biol. Bull. 82 (3) : 413 - 422; 4 text figs. Loosanorr, Victor Lyon & CHartes A. NoMEJKo 1951. Existence of physiologically-different races of oysters, Crassostrea virginica. Biol. Bull. 101 (2): 151 - 156 2 text figs.; 1 table LoosanorF, Victor Lyon & Frances DoreTTA TOMMERS 1948. Effect of suspended silt and other substances on the rate of feeding of oysters. Science 107 (2768): 69-70; 2 figs. NEEDLER, ALFREDA BERKELEY 1934. | Crowding and sex reversal in Ostrea virginica. Ann. Reprt. Biol. Brd. Canada 1933: 30 THE VELIGER Vol. 12; No. 1 Orton, JoHn H. 1927. | Observations and experiments on sex-change in the Eu- ropean oyster (O. edulis). Part I. The change from female to male. Journ. Mar. Biol. Assoc. 14 (4): 967 - 1045; 4 text figs.; 12 tables 1933. | Observations and experiments on sex change in the European oyster (Ostrea edulis). Part III. On the fate of the unspawned ova. Part IV. On the change from male to female. Journ. Mar. Biol. Assoc. 19 (1): 1 - 53; 8 text figs. 22 tables Orton, Joun H. & C. AMIRTHALINGAM 1931. | Observations and experiments on sex-change in the Eu- ropean oyster (O. edulis). Part II. On the gonad of egg- spawning individuals. Journ. Mar. Biol. Assoc. 17 (2): 315 - 324; 12 text figs.; 1 table Rovucu Ley, T. C. 1933. The life history of the Australian oyster Ostrea com- mercialis, Proc. Linn. Soc. N.S. W. 58 (3/4): 279 - 333; 18 plts.; 2 text figs. ScHaErer, MILNER B. 1938. Preliminary observations on the reproduction of the Japanese common oyster Ostrea gigas in Quilcene Bay, Wash- ington. Biol. Reprt.: Wash. State Dept. Fish. 36E: 1 - 36 Sevitta, Maria Luisa H. & EvA Monpracon C. 1965. Desarollo gonadico de Crassostrea virginica GMELIN en la Laguna Tamiahua. 1: 51-69 SrauBer, LESLIE A. Anales Inst. Nat. Invest. Biol. Pesc. 1950. The problem of physiological species with special ref- erence to oysters and oyster drills. 2 text figs.; 1 table TOwNSEND, CHar.es H. Ecology 31(1): 109- 118 1893. Report of observations respecting the oyster resources and oyster fishery of the Pacific Coast of the United States. Reprt. Comm. U.S.Comm. Fish and Fish. 1889-1891. 17: 343 - 372; plts. 2-11; 8 tables Vol. 12; No. 1 THE VELIGER Page 37 Levels of Spontaneous Electrical and Acetylcholinesterase Activities During Aestivation of the Indian Apple Snail, Pila globosa BY P MURALI MOHAN AND P MURALI KRISHNA DASS Department of Zoology, S. V. University College, Tirupati (A.P.), India (1 Text figure) INTRODUCTION Tue INDIAN APPLE SNAIL, Pila globosa (SwaInson, 1822) aestivates under drought conditions by retiring into the deeper layers of the mud and sealing itself with the oper- culum (PrasHap, 1925; Saxena, 1956). The general me- tabolism of the animal decreases to a low level during aestivation (MEENAKSHI, 1956; RAaGHUPATIRAMIREDDY, 1965). Under these conditions, it is likely that the nervous activity could also be low, since the necessity to respond to external environment does not arise. Moreover, the altered metabolism in aestivating snails may require a corresponding altered neuro-regulatory mechanism. Since the existence of such a mechanism is not known, an at- tempt was made to study these aspects, taking nervous activity as well as acetylcholinesterase activity as an index in aestivated animals. MATERIALS anp METHODS Active snails, Pila globosa, were made to aestivate for one month by embedding them in dry sand in wooden boxes (Saxena, 1956). The normal and aestivated Pila were dissected, expo- sing the different nerve cords under the binocular micro- scope. The spontaneous electrical activity was recorded by chlorided silver electrodes. The potentials were fed into the Tektronix 502A dual beam oscilloscope through Grass p9 preamplifiers. The photographic recordings were made using a Grass Kymograph camera. For the estimation of acetylcholinesterase activity, the nervous tissue including all ganglia and cords, of normal and aestivated Pila was isolated and washed repeatedly with gastropod Ringer solution (HucHES & KERKUT, 1956). The nervous tissue of each animal was used for a single analysis. The acetylcholinesterase (AChE) activ- ity was estimated following the modified method of MetTca tr as suggested by Murat KrisHna Dass (1968). The incubation mixture contained 0.1 ml of 5% homo- genate of the nervous tissue in 0.25M sucrose, and 1 ml of buffer-substrate mixture. After 4 an hour of incubation, the unreacted acetylcholine was determined by measuring the optical density at 540 my using Ultraviolet Spectro- photometer (Hilger and Watts, England), employing glass cuvettes of 10 mm light path. RESULTS anp DISCUSSION The level of spontaneous electrical activity has shown a definite decrease in all the nerves of the aestivated Pila from that of the normal as is evident from the recordings (Figure 1). Both the amplitude and frequency of the responses were affected on aestivation. A lower level of spontaneous activity parallels the lowered level of the active state of the animal (K.P. Rao, 1964; VeNxKaTa- cHari, 1968). Hence during aestivation, while the animal remains in a state of torpor, a decreased level of spon- taneous activity is expected. Similar decrease in electrical activity was observed in the brain and ganglia of pupae of diapausing insects (TySHTCHENKO & MANDELSTAM, 1965; Kutyna & TomBes, 1966). 40onV | 0.4. sec Figure 1 Spontaneous activity recorded from cerebral commissure (a1, a2), supra-intestinal nerve (b 1, b2) and left pleuro-visceral connective (c 1, c2) in normal (a1, b1, c1) and aestivated (a2, b2, c 2) Pila globosa Note the decrease in the spike amplitude and frequency of pulses on aestivation A direct relationship between electrical activity and AChE activity was demonstrated in relation to the behav- ior of scorpion (VENKATACHARI & Murat KrisHNA Dass, 1968). Since in the present case a considerable decrease in the spontaneous activity was observed, it is possible that the associated AChE activity might also have a corresponding decrease in activity. As is evident from ‘Table 1, there is a decrease in the AChE activity level Table 1 Levels of acetylcholinesterase enzyme activity in normal and aestivating Pila globosa. (Activity is expressed in mg of acetylcholine metabolised per gm weight of tissue per hour). Normal snails Aestivating snails % decrease during aestivation 338 + 20.09 281.33 + 17.78 16.76 (P > 0.001) Each value in this table is an average of six separate analyses (six animals).- THE VELIGER Vol. 12; No. 1 in nervous tissue of aestivated snails. This observation may possibly reiterate the direct relationship between elect- rical activity and AChE activity. Since the nervous system in general is known to regulate the activities of the animal, the lowered nervous activity of aestivating snails in terms of decreased spontaneous and acetylcholinesterase activities could be responsible for their observed lowered metabolism. Further work along these lines is in progress. SUMMARY 1. The spontaneous electrical and acetylcholinesterase ac- tivities were studied in the nervous tissue of normal and aestivated Pila globosa. 2. The spontaneous activity decreased in aestivated snails. Correspondingly, there was a decrease in the AChE activity. ACKNOWLEDGMENTS The authors wish to express their thanks to Dr. K.S. Babu and Dr. K.S. Swami of this Department for their kind help and valuable suggestions. LITERATURE CITED Hucues, G. M. « G. A. KerKutT 1956. Electrical activity in a slug ganglion in relation to the concentration of Locke solution. Journ. Exp. Biol. 33: 282 - 294 Kutyna, FE A. « A. S. ToMBEs 1966. — Bioelectric activity of the central nervous system in nor- mal and diapausing alfalfa weevils. Nature 212: 956 - 957 MEENAKsSHI, V. R. 1956. Studies on physiology of Pila virens (LAMARCK) with special reference to aestivation. Ph. D. thesis, Annamalai University, India Mura. KrisHna Dass, P. 1968. A modified method of Metcalf for AChE assay in nervous and muscular tissues of different animals. | Unpubl. NacHMANSOBN, D. 1953. | Metabolism and function of the nerve cell. Harvey Lectures 44: 57 - 99 Prasuap, B. 1925. Anatomy of the Indian apple snail Pila globosa. Mem. Ind. Mus. 8: 91 - 153 RAGHUPATIRAMIREDDY, S. 1965. The charge properties and metabolism of animals ex- posed to changed environments. Ph. D. thesis, Sri Venka- teswara University, India Vol. 12; No. 1 THE VELIGER Pampapati, Rao K. 1964. | Neurophysiological studies on an arachnid scorpion, Heterometrus fulvipes. Journ. Anim. Morphol. Physiol. 11; 133 - 142 Saxena, B. B. 1956. | Some observations on the ecology and behaviour of the common Indian apple snail, Pila globosa (Swainson). Journ. Bombay Nat. Hist. Soc. 53: 733 - 736 TYSHTCHENKO, V. P & J. E. MANDELSTAM 1965. A study of spontaneous electrical activity and localiza- tion of cholinesterase in the nerve ganglia of Antheraea pernyi Guer at different stages of metamorphosis in pupal diapause. Journ. Insect. Physiol. 11: 1233 - 1239 VENKATACHARI, S, A. T. 1968. Electrical activity of the ventral nerve cord of scorpion. Ph. D. thesis, Sri Venkateswara University, India. VENKATACHARI, S, A. T. & P Murai KrisHNA Dass 1968. Cholinesterase activity rhythm in the ventral nerve corc of scorpion. Life Sciences 7: 617 - 621 Page 39 Page 40 THE VELIGER Vol. 12; No. 1 Macoma (Psammacoma) pulleyi, a New Clam from Louisiana BY PAUL S. BOYER Department of Geology, Rice University, Houston, Texas ‘77001 (2 Text figures) THE FOLLOWING PELECYPOD was dredged by the author in the course of investigations of invertebrate ecology off the coast of Louisiana. Reference to published descrip- tions and comparison with the collections in the U.S. National Museum indicate that this clam is a new species. PELECYPODA TELLINIDAE Macoma Leacu, 1819 (Psammacoma) Dati 1900 Macoma (Psammacoma) pulleyi Boyer, spec. nov. (Figure 1) Description: Shell thin, white, moderately inflated, elon- gate, inequilateral, equivalve, and covered by a very thin, brown periostracum. Anterior end longer, the anterior dorsal margin almost rectilinear, the anterior margin rounded above and more gently and evenly curved below. Ventral margin nearly straight, subparallel to the anterior dorsal margin, and intersecting the posterior margin ab- ruptly at an angle of about 120°. Posterior dorsal margin sloping steeply, and meeting the posterior margin in a curve. Surface of shell beneath periostracum lusterless white, and smooth except for very fine incremental growth lines; an obtuse, rounded ridge running from the umbo to the posterior ventral angle marks the intersection of the posterior slope with the surface of the disk: this ridge is better defined in the left valve, where the posterior slope is occupied by a broad, very shallow sulcus. Hinge plate very narrow, bearing in the left valve a bifid ante- rior cardinal tooth and a lamellar posterior cardinal tooth; right valve with a bifid anterior cardinal tooth and a smaller, grooved posterior cardinal tooth. Ligament area shallow; posterior area not sharply defined. Pallial sinus mildly discrepant between the valves: in the left valve, obliquely rising from the posterior adductor muscle scar, sinuous above, narrowing and extending forward about = of the distance between the adductor muscle scars, bluntly rounded anteriorly, about half confluent with the pallial line below; in the right valve obliquely rising from the posterior adductor muscle scar, smoothly rounded above, sloping in a straight line anteriorly, somewhat less bluntly rounded anteriorly, extending forward about # of the distance between the adductor muscle scars, about half confluent with the pallial line below. There is a slight posterior gape (about 1.5 mm in the holotype), and the posterior end is angled to the right almost imperceptibly. The anterior dorsal margin of the right valve overlaps the left valve slightly; in front of the umbo of the left valve there is a small incised area for the partial recep- tion of the overlapping portion of the right valve. Measurements (in millimeters) Length Height Diameter Holotype 42.0 Done 12.4 1* Paratype 40.8 opacd) 12.0 2¢ Paratype 44.5 23.8 13.9 3™ Paratype _ 28.6 15.1 8.3 4" Paratype 55.3 29.8 16.7 Type Locality: The holotype was collected live offshore from Plaquemines Parish, Louisiana, 28°59’ N Latitude, 89°30’ W Longitude, 18 m water depth, in silt substrate, salinity (interpolated from adjacent stations) 15%, at surface, 31%, at bottom, 9 June 1965. Known Range and Habitat: Macoma pulley: was collec- ted west of the Mississippi Delta, offshore from Terre- bonne, Lafourche, Jefferson, and Plaquemines parishes, Louisiana, in mud substrate, in water depths of from Vol. 12; No. 1 THE VELIGER Page 41 13 to 45 m, in bottom water having nearly normal salin- ity (30 to 33%). The unusually large 4" paratype was dredged dead in 19m water depth farther west, from a patch of sandy mud substrate 52 km south of the mouth of the Mermentau River, Cameron Parish, Louisiana. Parker illustrates this species (PARKER, 1956; plt. 1, figs. 8A, 8B; the same pictures appear in Parxer, 1960, pit. 4, figs. 14A, 14B) as Macoma tageliformis. He lists several localities (PARKER, 1956, p. 315, table II) for M. tageliformis which probably refer to M. pulleyi. These localities are east of the Mississippi Delta: live specimens were common at the delta front, and dead valves were found in the shallow shelf area. United States National Museum no. 189186, collected from Louisiana by L. R. Cary, is this species. Disposition of Specimens: Holotype deposited in the Mu seum of Comparative Zoology at Harvard University, no. 271577; 1* paratype (Figure 1) in the author’s collection; 2™ paratype in the U. S. National Museum; 3°: paratype Figure 1 Macoma pulley Boyer, spec. nov. First Paratype A. Interior, right valve C. Exterior, right valve — matching valves B. Interior, left valve D. Exterior, left valve in the Academy of Natural Sciences of Philadelphia; 4" paratype in the Bureau of Economic Geology, The University of Texas, Austin. Remarks: Macoma (Psammacoma) pulleyi has been con- fused with the sympatric M. (P) tageliformis Dat, 1900. Macoma tageliformis was originally described from Cor- pus Christi Bay, Texas, but was not figured (Dau, 1900a, pp. 300, 315). Another description, also without figures, appeared about a month later (Dat, 1900b, p. 1055). Subsequently, illustrations were published of a specimen from Puerto Rico (Dati « Simpson, 1901, plt. 55, figs. 10, 11, 15) which was identified as M. tageliformis. Dati « Smmpson’s figured specimen (U.S. National Museum no. 160497) is relatively much shorter than the holotype of M. tageliformis (U.S. National Museum no. 6086) ; the illustrated specimen also differs from the holotype in having a steeper posterior dorsal margin, which makes it look superficially like M. pulley:. Thus Datw’s choice of specimen to illustrate as Macoma tageliformis may have caused some of the confusion surrounding that species. Collections of Macoma tageliformis from Louisiana agree perfectly with Datt’s holotype. Figure 2 is a speci- men of M. tageliformis from sandy silt substrate, 19 m water depth, 39km south of Rollover Bayou, offshore from Vermilion Parish, Louisiana. Macoma tageliformis and M. pulleyi may easily be distinguished by the following differences: a) Macoma tageliformis is more noticeably inequivalve, its left valve being more convex than its right. b) In Macoma tageliform: ‘he ligament area is depressed, so that the surface of .he posterior area on either side is almost vertical and is set off from the rest of the shell by a rather sharp ridge; the posterior area is not so defined in Macoma pulleyi. M oma pulley: has a rather abrupt posterior ventral an ,ie; also Macoma pulley: bears a ridge delineating the poste- rior slope from the surface of the disk. These last two features are lacking in M. tageliformis. Figure 2 Macoma tageliformis Dat, 1900 Matching valves. Offshore from Vermilion Parish, Louisiana A. Interior, right valve B. Interior, left valve C. Exterior, right valve D. Exterior, left valve Page 42 e) The pallial sinus of Macoma pulleyi extends farther forward than that of MM. tageliformis. The closest relative of Mfacoma pulleyi would seem to be the Miocene species M. holmesii Dati, 1900, from Duplin County, North Carolina. Macoma pulleyi is dedicated to my friend Dr. T. E. Pulley, of the Houston Museum of Natural Science. Dr. Pulley is an authority on the mollusks of the Gulf Coast. ACKNOWLEDGMENTS The author wishes to acknowledge the support of a National Aeronautics and Space Administration fellow- ship and of National Science Foundation Grant GP-3600, and the use of the facilities of the Geology Department of Rice University. Dr. Robert R. Lankford supervised the project of which this study is a part; he also critically read the manuscript and contributed many helpful sug- gestions. THE VELIGER Vol. 12; No. 1 LITERATURE CITED Dati, WiLL1iAM HEALEY 1900a. Synopsis of the family Tellinidae and of the North American species. Proc. U.S. Nat. Mus. 23 (1210) : 285 to 326; plts. 2-4 (14 November 1900) 1900b. Contributions to the Tertiary fauna of Florida, with especial reference to the silex-beds of Tampa and the Pliocene beds of the Caloosahatchie River, including in many cases a complete revision of the generic groups treated of and their American species. Part V. Teleodesmacea: Solen to Diplodon- ta. Trans. Wagner Free Inst. Sci. Philadelphia 3 (5) : 949 to 1218; plts. 36 - 47 (December 1900) Dai, WiLtiaM HEALEY & CHARLES TorrEY SIMPSON 1901. The Mollusca of Porto Rico. U.S. Fish Comm. Bull. 20 (1): 351-524; plts. 53 - 58 (November 1901) Parker, Rospert H. ; 1956. Macro-invertebrate assemblages as indicators of sedi- mentary environments in east Mississippi Delta region. Bull. Amer. Assoc. Petrol. Geol. 40 (2): 295-376; 32 figs.; 8 plts. 1960. Ecology and distributional patterns of marine macro- invertebrates, northern Gulf of Mexico. In: Recent sediments, northwestern Gulf of Mexico, ed. F R. SHeparp, EB. PHLEGER « T.H. Van ANDEL, pp. 302 - 337; 6 plts.; 17 text figs. Amer. Assoc. Petrol. Geol., Tulsa, Oklahoma Vol. 12; No. 1 THE VELIGER Page 43 On Pseudopythina rugifera (CARPENTER, 1864) (Bivalvia) WALTER NARCHI Faculdade de Filosofia, Ciéncias e Letras da Universidade de Sao Paulo, Sao Paulo, Brasil (9 Text figures) INTRODUCTION LitTLE Is KNOWN of the structure, functions of the organs in the mantle cavity, and the adaptations found in the Leptonacea, composed largely of commensal species, in correlation with their specialized mode of life. PopHaM (1940, p. 549) refers to the biology of some species belonging to the genera Kellia, Lasaea, Montacuta, Mysella, Devonia and Galeomma. Ceratobornia cema (= Lepton cema Narcut, 1966) was intensively studied. Other genera were studied but no references were found for Pseudopythina. Pseudopythina rugifera (CARPENTER, 1864) occurs on the Pacific Coast of North America from Alaska to Lower California (ApBoTT, 1954, p. 395; PALMER, 1958, p. 90). According to Kren (1937, p. 25) it ranges from 37° to 48° North Latitude. The species is well known in the eastern Pacific as an “ectoparasite” of the crustacean Upogebia pugettensis (Dana, 1852) and could be found attached by its byssus to the ventral surface of the poly- chaete worm, Aphrodita (OLpRoyp, 1924, p. 136; Mac- Ginitre & MacGrinrrig, 1949, p. 348; Parmer, loc. cit.; Boss, 1965, p. 186). Otproyp (Joc. cit.) states that all species of the genus Pseudopythina FiscHER, 1884, are commensals. In this paper observations on the structure, ciliary currents of feeding and digestion, and some other functional adaptations of P rugifera are studied. The animals were found attached to the broad annu- lated foot of Aphrodita refulgida Moore, collected at Tomales and at Bodega Bay, Marin County, California (Figure 1). Several specimens were examined alive and the ciliary currents in the mantle cavity were observed with use of carmine, aquadag, and powdered carborun- dum. Others were fixed in Bouin’s fluid. Serial sections of 6m were made and the sections stained in Delafield’s hematoxylin, eosin and Alcian blue, to examine the gen- eral anatomy. The observations on living specimens were made at the Pacific Marine Station, Dillon Beach, Cali- fornia. Figure 1 General view of several specimens of Pseudopythina rugifera attached to Aphrodita SHELL anp MANTLE The shell is small, oval-oblong, moderately obese and frag- ile, reflecting the protected habitat of this species. The umbones are close together, and located near the middle line of the shell. Lateral teeth are absent and one large central tooth (Figure 2) exists on each valve (CarPEN- THE VELIGER Vol. 12; No. 1 Page4$ 0 Oe Figure 2 View of the hinge of Pseudopythina rugifera (X 40) TER, cited by PaLmeEr, 1958, p. 90). The shell is covered with a thin, light brown periostracum which is concent- rically wrinkled. The embryonic shell is still visible in the adult near the umbo. Foraminifera were found frequent- ly attached to the shell. The shell of the largest animal encountered in this study measured 6mm in length, 2.5 mm in height, and 1.5mm in width. The species possesses both an external and an internal ligament, the latter being much more developed. As in Kellia suborbicularis (Montacu, 1803), the shell and the fleshy parts of Pseudopythina rugifera are white in color (OtprreLp, 1961, p. 257). In living animals the foot protrudes from the shell to a distance equal to half the length of the shell. The mantle edges, the inhalant and exhalant siphons do not extend beyond the shell valves as in Montacuta substriata (PopHam, 1964, p. 564). As in Montacuta ferruginosa and M. substriata (OLp- FIELD, 1961, p. 260), there are only two pallial openings: a large, inhalant and pedal aperture in the anterior and ventral part of the body, and a small exhalant aperture posteriorly located. The inner mantle folds are fused be- tween these two apertures in a very short extension. The exhalant siphon is shorter and formed by the inner mantle folds. The edges of this siphon bear small papillae of which one dorsal and one ventral papilla are slightly larger and can be seen protruding out of the shell. The mantle edge has three folds. The outer fold is enclosed by the periostracum and has a flattened epi- thelium. The middle fold bears few papillae and secretes the periostracum. The inner fold contains the circumpal- lial nerve. The folds are very similar to those of Kellia suborbicularis (OLDFIELD, 1961, p. 260). In the dorsal part of the inner mantle fold, from the region of the stomach up to the pallial fusion, a tract of strongly cili- ated cells occurs. This tract is concerned with the rejection of particles from the mantle. The free edge of the mantle surrounding the inhalant siphon and pedal opening is also ciliated. Particles falling on this edge are passed into the mantle cavity. , Tue CTENIDIA Both demibranchs are present in Pseudopythina rugifera (Figure 3), but the outer demibranch (od) is less than half the depth of the inner (id). Only the inner demi- branch has a food groove along its ventral edge. Lam- mellae are flat and homorhabdic, as found in the Leptoni- dae (Atkrns, 1937, p. 391). Behind the foot (f), the left and right inner demibranchs are joined together in the median plane. As in Kellia suborbicularis (OLDFIELD, 1961, p. 263), both outer and inner demibranchs on each side are fused ventrally to the mantle, in the region where the fused inner folds of the mantle separate the common inhalant and pedal aperture from the exhalant aperture. Hin Figure 3 Pseudopythina rugifera (CARPENTER, 1864) Mantle cavity viewed from the left side after removal of the left shell valve and mantle lobe, showing ciliary currents. a-— anus am — anterior adductor muscle _ b — byssus arp — anterior retractor pedis muscle dd — digestive diverticula exs — exhalant siphon f — foot g — foot groove id — descending lamella of inner demibranch __ li—inner labial palp lo—outer labial palp | oa—ascending lamella of outer demibranch prp — posterior retractor pedis muscle | w — waste material pm — posterior adductor muscle te — tentacle The gill filaments are numerous. Slender interfilamentar junctions are numerous but interlamellar junctions are few. This condition is found in other species where the incubatory habit occurs (OLDFIELD, 1961, p. 263). The ciliary mechanism in the ctenidia of Pseudopythina rugifera is similar to that of Kellia suborbicularis (At- Vol. 12; No. 1 KINS, 1937, p. 389). The ctenidia and their ciliation are as in Type C(1) of Atkins (loc. cit.). There is no interruption of the latero-frontal cilia at the ventral tip of the filaments of the ctenidia, but rather a bending of the filaments. The frontal currents on the outer demibranch are directed ventrally on the ascending lamella, bend at the free edge and flow dorsally on the descending lamella. The frontal cilia are not modified. In the free edge of the outer demibranch no longitudinal currents occur. The frontal currents on the inner demibranch are direc- ted ventrally on the ascending and descending lamellae. In the free edge of the inner demibranch an oral longi- tudinal current occurs. Other oral currents occur between the bases of the two demibranchs of each side of the body. Along the marginal grooves of the inner demibranch shorter guarding cilia exist. On each ventral tip of the filaments these cilia beat as a group, moving particles to the anterior part of the body. The fine frontal cilia are continued on each side and beat directly to the ventral part. eT EAI WEN oie tide OH % a BN THE VELIGER Page 45 The long lateral cilia form an inhalant current and the frontal cilia convey food particles along the filament to the food groove. There is one type of latero-frontal cilia: the eu-latero- frontal cilia which are fused, large, and prevent the loss of food particles into the supra branchial chamber. As in Kellia suborbicularis (OLDFIELD, 1961, p. 264), guarding cilia exist on both sides of the food groove and these cilia prevent the entrance of coarse particles into the groove. ATKINS (1937, p. 360) suggests that guarding cilia occur when the animals live in a silt or muddy sub- strate. MUSCULATURE The anterior adductor muscle (Figure 4, am) is slightly larger than the posterior adductor muscle (pm). The re- jected material is violently shot out of the pallial cavity by a sudden contraction of the adductors. PopHam (1940, p. 564) describes the same phenomenon for Kellia suborbicularis. OLDFIELD (1961, p. 264) believes Figure 4 Pseudopythina rugifera (CARPENTER, 1864) Diagrammatic representation of the organs in the mantle cavity am — anterior adductor muscle arp — anterior retractor pedis muscle bl — byssogenous lamella dd — digestive diverticula i — intestine au — auricle bgi- main byssus gland cg — cerebral ganglion f — foot g — foot groove ia — ascending lamella of inner demibranch ss — style sac oa — ascending lamella of outer demibranch prp — posterior retractor pedis muscle ve — ventricle id — descending lamella of inner demibranch li — inner labial palp _lo — outer labial palp k — kidney bv — ovary oe — oesophagus pm — posterior adductor muscle r—rectum s—stomach pg — pedal ganglion vg — ventral ganglion Page 46 that this is probably essential in species which live in a sandy or muddy habitat and prevents the danger of their silting up. Each adductor muscle is subdivided equal- ly into two parts, as in Kellia and Montacuta. There are two pairs of muscles of the foot: a pair of anterior retractor pedis muscles (arp) and a pair of pos- terior retractor pedis muscles (prp). As in Kellia and Montacuta, there is no elevator pedis muscle. The anterior retractor pedis muscle is completely subdivided into a smaller retractor pedis muscle and a larger byssus retractor muscle. As in Montacuta substriata (OLDFIELD, 1961, p. 267) the well developed byssus mus- culature is related to the high development of the byssus apparatus in this species. In Pseudopythina rugifera the protractor pedis muscle runs through the lower part of the anterior retractor pedis muscle, but is inserted to- gether with the byssus retractor muscle (br), while in M. substriata they have a separate origin from the shell (OLpFIELD, 1961, p. 267). THe FOOT The foot is large and though laterally compressed, has a flat creeping sole by means of which it is capable of active locomotion. It is slender and, when fully distended, is half the length of the shell, but it can be completely withdrawn when the shell valves are closed. The large pedal aperture combined with the inhalant aperture per- mits the foot to move in a wide angle. As in Montacuta substriata (PopHam, 1940, p. 565), rocking movements are possible because of the gape and the large size of the pedal opening. The byssus cavity (bg) lies posteriorly in the foot and opens by way of a byssus canal into a groove (g) which extends on the ventral side almost to the tip of the foot. In M. substriata (PopHaM, loc. cit.) two or three threads are produced but in Pythina rugifera the number is greater. The ventral and ventro-lateral surfaces of the foot are covered by a ciliated columnar epithelium, as are the surface of the byssogenous lamellae (bl), the byssus canal and groove. The viscera do not extend into the foot. In the foot there are many muscle fibers and connective tissue with large blood spaces. Pseudopythina rugifera lives attached to the foot of the sea mouse by a large byssus (b) composed of a large number of threads. The byssus cavity is embedded in the main byssus gland and is divided by a fold into two large longitudinal parts (Figure 5). Each part is divided into 10 to 12 slit-like compartments by the byssogenous lamel- lae. Each lamella is composed of connective tissue and THE VELIGER Vol. 12; No. 1 Figure 5 Pseudopythina rugifera (CARPENTER, 1864) Byssus gland and byssus thread fine muscle fibers from the byssus retractor muscle. A ciliated columnar epithelium covers the lamellae and is composed of low columnar cells. The byssus apparatus of P. rugifera is very similar to that found in Potidoma sub- trigonum (Derrovux, 1961, p. 119). The glandular cells of the main byssus gland (bgi) surround the byssus cavity. From these cells, in which the cytoplasm laden with fine granules, stains in aniline blue, long slender ducts lead to openings between the ciliated epithelial cells covering the surfaces of the byssogenous lamellae, in the byssus cavity. Thus the secretion of the main byssus gland forms a coating to the lamellae, and these sheets of secretion coalesce to form the stalk of the byssus. The byssus canal is ciliated on its anterior and lateral walls and the byssus groove is ciliated throughout its entire length. Vol. 12; No. 1 THE VELIGER Page 47 eee The main mucus gland occupies the anterior part of the foot and extends along both sides to the posterior end of the foot. From these mucus cells slender ducts open on the byssus groove on the ventral and ventro-lateral surfaces of the foot. The construction of the byssus threads by adult animals was observed in the laboratory. A new byssus thread is constructed in 30 seconds and this velocity is probably due to the habits of the animal. To build a new byssus thread the foot is placed on the sole of the sea mouse. It becomes temporarily attached, apparently by a sucker- like action, and does not move. Only the tip of the foot moves laterally back and forth, until the byssus thread is completed. Pseudopythina rugifera, detached from the sole of Aph- rodita, with very active locomotion attached itself to the ventral part of the animal in a few seconds. As in Mont- acuta substriata (PopHaM, 1940, p. 566), the surface of the foot is strongly ciliated. Particles move rapidly across the sides of the foot from the tip to the heel and are passed off into the main rejection current concerned with the rejection of waste material, which passes out between the shell valves in a posterior and ventral direction im- mediately behind the foot. LABIAL PALPS The labial! palps are relatively small; their opposed sur- faces are covered by cilia and they have 9 transverse ridges. The ridged and grooved surfaces function as a sorting region. Particles of food and other material are swept onto the palps from the food groove of the inner demibranch. On the crests ot the folds, particles are carried forward from fold to fold towards the mouth. On the floor of the grooves, between adjacent folds, particles are driven to the ventral border of the palp and from there moved to the tip of the palp where they are rejected. The ventral tips of the anterior filaments of the inner demibranch are not inserted into a distal oral groove, although the antero-ventral margin of the inner margin of the inner demibranch is fused to the inner palp lamella and belong to the Category III of the association of ctenidia and labial palps (Stasex, 1963, p. 91). THe ALIMENTARY CANAL GENERAL STRUCTURE The small size of the specimens made it difficult to study and observe the internal structure of the stomach in great detail. The alimentary canal was dissected in specimens that had been preserved in alcohol. The in- ternal structure of the stomach was studied in living specimens. The stomach was opened from the surface by a mid-dorsal incision through the roof, and the right side of the stomach was drawn downwards. The ciliary cur- rents were determined with the aid of carmine, aquadag and fine carborundum particles. The nomenclature used by GraHam (1949), Owen (1953), PurcHoN (1955), and Rem (1965) has been followed. The mouth opens into the oesophagus ( oe) which joins the stomach (s) at the anterior and ventral part, which is thin-walled and globular. The stomach is approximately cylindrical in shape and is surrounded by the digestive diverticula (dd). The combined style-sac (ss) and intestine open into the posterior and ventral region of the stomach; the style-sac and intestine intercommunicate by an opening. This open- ing was observed in Montacuta by PELSENEER (cited by OpriELp, 1961, p. 273) but it was not seen by her in the same genus. The style-sac and intestine are joined in a short extension; after this, the intestine leaves the style- sac on the right side. The intestine (i), after a small loop, ascends dorsally and then continues as a very well de- veloped rectum (r).'The rectum passes over the posterior adductor muscle and finally opens into the anus (a) close to the exhalant aperture. STRUCTURE or tut STOMACH Pseudopythina rugifera has a stomach of type 4 (Figure 6), as defined by Purcuon (1958, p. 488). The minor typhlosole is absent in this species. PuRCHON (op. cit., p. 489) states that the minor typhlosole appears to be ab- sent in the Anomiidae, Erycinidae and Montacutidae. The major typhlosole (ty) projects into the stomach, pas- ses forwards from the aperture of the mid-gut and curves gradually to the left over the floor of the stomach. The major typhlosole is accompanied on its right side by the intestinal groove (ig). A sorting area consisting of a small number of folds and grooves is present on the anterior face of the stomach between the orifice of the oesophagus (oe) and the intes- tinal groove. This sorting area extends on to the left anterior wall of the stomach, invades the left pouch (Ip) and ends close to the terminal region of the major typhlo- sole. The intestinal groove is enveloped by the sorting area. There is a relatively small dorsal hood (dh), the aper- ture of which is penetrated by a lobe of the gastric shield (Figure 7, gs). The dorsal hood lies on the left anterior Page 48 Figure 6 Pseudopythina rugifera (CARPENTER, 1864) Interior of the stomach, seen from the right side, after an incision through its right side extending into the style sac dh - dorsal hood gs — gastric shield Ip — left pouch mg — midgut oe — oesophagus ss — style sac ig — intestinal groove r, — ciliated ridge ty — major typhlosole Figure 7 Pseudopythina rugifera (CARPENTER, 1864) Transverse section of the stomach ep — epithelium gs — gastric shield _st — style THE VELIGER Vol. 12; No. 1 stomach wall, as in Scintilla hanleyi (PuRcHOoN, 1958, p. 498). The epithelium of the stomach underlying the gastric shield consists of tall narrow columnar cells each with an oval nucleus near the base of the cell (Figure 8). The distal region is packed with almost spherical granules up to 4u in diameter. Similar spherical granules were found in cells of the stomach of Nuculidae (Owen, 1953, p. 545). Surrounding the cells of the epithelium there is a layer of collagen and a system of smooth circular muscle fibers. The crystalline style projects obliquely upwards and its tip is placed in the aperture of the dorsal hood. The left pouch is on the left wall of the stomach. The upper border of the left pouch is penetrated by a lobe Aen antes wa ih Wy Lali tit 40h Figure 8 Epithelium of the stomach showing spherical granules of the gastric shield. The left pouch receives one duct from the digestive diverticula on the left side of the body. In the grooves of the sorting area the cilia beat to- wards the intestinal groove, while the cilia on the tops of the ridges beat towards the dorsal hood as in Gale- omma glycymeris (Reip, 1965, p. 169). A circulating current is set up by the cilia on the top of the sorting area. It is this general circulation which Vol. 12; No. 1 carries large particles and masses of particles towards the dorsal hood and gastric shield. Light particles are carried in the current flowing across the ridges of the sorting area into the dorsal hood. Heavy particles are driven against the surface of the sorting area and fall into the transverse rejection grooves. Small and heavy particles are carried away to the intestinal groove and then into the mid-gut. The sorting area in Pseudopythina rugifera is composed of large ridges and wide grooves. The cilia on the crests of the folds beat, carrying particles to the left region of the stomach. As in Scintilla hanley: (PuRcHoN, 1958, p. 499) there is no sorting area within the dorsal hood, nor is there one on the right wall of the stomach. From the oesophagus a narrow ciliated ridge (r:) passes backwards from the left corner of the oesophageal orifice to the dorsal hood. The dorsal hood receives particles from the anterior part of the stomach by means of that ridge. A similar ridge was described by PurcHon (1958, p. 499) in Scintilla hanleyi. The sorting area is small; large particles are not rejec- ted and excessive quantities of small particles are accepted (PurcHon 1958, p. 487). EXCRETORY SYSTEM The kidney (Figures 9 C, 9 K) is composed of a pair of elongated sacs with glandular walls which intercommuni- cate in the median part, ventral to the pericardial cavity. Each kidney sac is lobed ventrally and dorsally and there are no internal folds of the wall to produce spongy kid- ney. It opens directly at its anterior end to the supra- branchial chamber by the external renal aperture, which has ciliated cells. These ducts (rpd) are long and they run posteriorly from the pericardial cavity and open into the posterior part of the kidney. Histologically this system is very similar to that of Kellia and Montacuta (OLDFIELD, 1961, p. 276). NERVOUS SYSTEM There are three pairs of ganglia: the cerebral, pedal, and visceral. The cerebral ganglia lie behind the anterior adductor muscle, one on each side of the oesophagus, and joined together by a supra-oesophageal commissure. The buccal nerve, the anterior adductor nerve, and the anterior retractor pedis muscle nerve arise from these ganglia. The pedal ganglia are so close together that they ap- pear as one, lying in the mid-line ventrally to the digestive THE VELIGER Page 49 diverticula. Each pedal ganglion gives rise to the anterior pedis nerve, the lateral pedis nerve, and the byssus nerve. The visceral ganglia lie on the anterior surface of the posterior adductor muscle, and have the branchial nerve, the posterior adductor nerve, and a posterior pallial nerve. The cerebro-visceral connective and the cerebro-pedal connective are similar to those described by OLpFIELD (1961, p. 280) for the genera Kellia and Montacuta. REPRODUCTIVE SYSTEM The specimens examined were females. The gonad is a large hollow organ with two anterior lobes, each subdi- vided into many lobules and communicating with a single, median posterior chamber. As in Kellia suborbicularis (OLpFIELD, 1961, p. 281), the posterior chamber opens on each side of the body by a short ciliated duct into the supra-branchial chamber of the inner demibranch. The external genital opening is immediately anterior to the exterior renal opening. As in Kellia suborbicularis (LEsour, 1938, p. 447) and other specialized eulamellibranchs (OxpFIELD, 1964, p. 79) fertilization occurs probably within the gills, the sper- matozoa of another individual being drawn in with the inhalant current. The specimens collected in April contained developing embryos (e) within the gills, and the gonad appeared empty with a few small atretic ova. Pseudopythina rugi- fera is not a common animal in Tomales Bay and further investigations may reveal male or hermaphrodite forms. More extensive collecting of animals would reveal if the species is a protogynous consecutive hermaphrodite in which there is no overlapping of male and female phases, as in Kellia suborbicularis and Montacuta ferruginosa (OLpFIELD, 1961, p. 289). DISCUSSION Pseudopythina rugifera is adapted to live attached and is found fixed by its byssus to the ventral surface of Aphro- dita or Upogebia. The species attaches and detaches itself at will, as observed by MacGrniTiE and cited by QUAYLE (1960, p. 74). The animal has a well developed foot and a wide pedal gape to allow the foot to be extruded. It has two pallial apertures, a large antero-ventral and a small posterior one. Concerning the ciliary mechanism of the ctenidia the species is similar to Kellia suborbicularis (OLDFIELD, 1961, p. 264) as both have guarding cilia in both sides of the food groove on the inner ctenidia. This suggests that the Page 50 (adjacent column —>) animal lives in a silt or muddy substrate. The manner in which the rejected material is violently shot out of the pallial cavity by a sudden contraction of the adductors proves that the animal lives in a sandy or muddy environ- ment (OLDFIELD, loc. cit.). The byssus apparatus is well developed with a large byssus retractor muscle as in Montacuta substriata which lives attached to the spines of the sea urchins. The byssus apparatus is divided in the middle by a fold into two longi- tudinal parts. Each part is divided into 10 to 12 slitlike compartments and is similar to Potidoma subtrigonum (JEFFREYS) described by Deroux (1961, p. 119). It is different from the other species belonging to the genera Kellia, Montacuta, and Lasaea. The absence of a well developed sorting area in the stomach suggests that excessive quantities of small par- ticles or large particles are not rejected. The rectum is very wide. The contents of the intestine THE VELIGER Vol. 12; No. 1 SS OY oe S| > tom, 8 40 eS . Y * ‘ —s Q ri aS e a \* \ Al © =. oe ss ov # fs ANS Sass) 8 | z b A s g.Os il. ° 6 Py SS Spe i GS fo fg aaa Wa snmandes Y bgi Ley WN ff 4 i VV 4 ie: =f mil mml mol Figure 9 Pseudopythina rugifera (CARPENTER, 1864) Diagrammatic transverse sections through the animal (X 72) A — at level of the stomach B — at level of the style sac C — at level of the kidneys bg — byssus cavity bgi — main byssus gland br — byssus retractor muscle dd — digestive diverticula e — embryos ex! — external ligament fg — food groove g — foot groove gs — gastric shield _i — intestine id — descending lamella of inner demibranch __ il—internal ligament k — kidney _mil — inner fold of mantle edge mml — middle fold of mantle edge od — outer demibranch mol — outer fold of mantle edge _— ov — ovary prp — posterior retractor pedis muscle r — rectum rpd — reno-pericardial duct _ ss — style sac _st — style when compared with those of the stomach show a larger number of more or less complete but empty diatom tests and protozoan skeletons. This suggests that while some Vol. 12; No. 1 lo) OQ | ? x 00 for sf : Ss a 5 % ss yo o 6 Z 2. Oo 8 8 C os Sg - See gWVZ ghee: iss” e Sey’ 3) (PS \ G, Q& Po, 0: %Go* od Opn A-) EPISODIO A ds me jam (<— on facing page) mechanical trituration occurs in the stomach, enzymes are also present (OWEN, 1956, p. 559). The stomach of Pseudopythina rugifera is in some aspects similar to that of Scintilla hanleyi, as both have two ciliated ridges from the anterior left face of the stomach to the dorsal hood. The oesophagus, the left pouch and the dorsal hood are similar in both species. While in P rugifera the style sac and the intestine inter- communicate by an opening, this is not found in S. hanley:. The style sac and intestine join in a short extension and the intestine leaves the style sac laterally on the right side. The sorting area in Pseudopythina rugifera starts in the right wall of the stomach, passes upwards from the region of the intestinal groove towards the oesophageal aperture to the left wall of the stomach and then surrounds the left pouch, ending close to the major typhlosole. Scintilla THE VELIGER Page 51 hanleyi has two sorting areas (PuRCHON, 1958, p. 498) : S; on the anterior face of the stomach which passes from the intestinal groove to the oesophageal aperture, and Su, the second sorting area, on the floor of the left pouch. It seems that P rugifera has a stomach more primitive than S. hanleyi, as the two sorting areas are joined into only one in the present species. The stomach of Pseudopythina rugifera is an example of simplification of structure: the major typhlosole is reduced. The sorting area directs particles toward the intestinal groove. The stomach of Pseudopythina rugifera probably tri- turates ingested particles by muscular action and the rela- tively large size of the stomach and style sac is an adapt- ation for the ingestion of large quantities of bottom ma- terial (OwEN, 1956, p. 562). SUMMARY Pseudopythina rugifera (CARPENTER, 1864) lives attached to the ventral surface of the polychaete worm Aphrodita and to the anomuran crustacean Upogebia. It occurs on the Pacific Coast of North America, from Alaska to Lower California. The shell is small, oval-oblong, and frag- ile, reflecting the protected habitat of the species. There are only two pallial apertures, a large anterior and vent- rally located one which is a common inhalant and pedal opening, and a small exhalant aperture. The siphons do not protrude beyond the shell. The ctenidia are similar to those of Kellia suborbicularis and both outer and inner demibranch on each side are fused ventrally. The byssus apparatus is well developed and is very sim- ilar to that of Potidoma subtrigona (DERoux, 1961, p. 1). The anatomy of the stomach is described in detail, and the stomach belongs to Type 4 (PurcHon, 1958, p. 488). Specimens collected in April contained developing em- bryos within the gills. Future research will prove if Pseu- dopythina rugifera is a protogynous consecutive herm- aphrodite in which there is no overlapping of male and fe- male phases as in Kellia suborbicularis and Montacuta ferruginosa. ACKNOWLEDGMENTS I wish to express my thanks to Dr. Edmund H. Smith, Director of the Pacific Marine Station, Dillon Beach, California for the use of the facilities and laboratories. Page 52 To the staff of the Marine Station my thanks are due for assistance in collecting. This work was made possible by a grant from the De- partment of the Interior (WP 010610), and by the finan- cial help to the Coordenagéo do Aperfeigoamento de Pessoal de Nivel Superior (CAPES), Rio de Janeiro, Brasil. LITERATURE CITED AssoTtT, RoBERT TUCKER 1954. | American seashells. Princeton, New Jersey, D. van Nostrand Co., Inc.; xiv+541 pp.; 100 text figs.; 40 plts. ATKINS, DAPHNE 1937. On the ciliary mechanisms and interrelationships of lamellibranchs. Part II. Sorting devices on the gills. Quart. Journ. Micr. Sci. 79: 339 - 373 Part III. Types of lamellibranch gills and their food currents. Quart. Journ. Micr. Sci. 79: 375 - 421 Boss, KENNETH JAY 1965. Symbiotic erycinacean bivalves. Malacologia 3 (2): 183 - 195 Deroux, G. 1961. Rapports taxonomiques d’un Leptonacé non décrit “Lep- ton subtrigonum” JEFFREYS (nomen nudum — 1873). Cah. Biol. Mar. 2 (2): 99 - 153 LeEsour, Marie V. 1938. The life history of Kellia suborbicularis. Biol. Assoc. U. K. 22: 447 - 451 KEEN, A. Myra 1937. An abridged check list and bibliography of west North American marine Mollusca. Stanford Univ. Press, Stanford, Calif.; pp. 1 - 88; 2 figs. (29 September 1937) MacGinitTie, Georce Esper & Nettie MacGInirtizE 1949. Natural history of marine animals. McGraw-Hill, New York. Narcui, WALTER 1966. The functional morphology of Ceratobornia cema, new species of the Erycinacea (Mollusca, Eulamellibranchiata) . An. da Acad. Brasileira de Ciéncias 38 (3/4) : 513 - 524 Journ. Mar. 473 pp.; illus. THE VELIGER Vol. 12; No. 1 OLpFIELD, E. 1955. Observations on the anatomy and mode of life of Lasaea rubra (Montacu) and Turtonia minuta (Fasrictus). Proc. Malacol. Soc. London 31 (5, 6): 226 - 249 1961. The functional morphology of Kellia suborbicularis (Montacu), Montacuta ferruginosa (MonTAGU) and M. sub- striata (MontTacu). Proc. Malacol. Soc. London 34 (5) : 255 - 295 1964. | The reproduction and development of some members of the Erycinidae and Montacutidae (Mollusca, Eulamellibranchi- ata). Proc. Malacol. Soc. London 36 (2): 79 --120 Oxproyp, IDA SHEPARD 1924. The marine shells of the west coast of North America. Stanford Univ. Publ. Geol. Sci., 1: 1 - 247; plts. 1-57 OwEN, GARETH 1956. Observations on the stomach and digestive diverticula of the lamellibranchia II. The Nuculidae. Quart. Journ. Micr. Sci. 97 (4): 541 - 567 =n PALMER, KATHERINE VAN WINKLE 1958. ‘Type specimens of marine mollusca described by P. P. Carpenter from the West Coast (San Diego to British Colum- bia). Memoir 76, Geol. Soc. Amer. i- viii + 1-376; plts. 1 - 35. New York, N. Y. (8 December 1958) Poruam, M.L. ; 1940. The mantle cavity of some of the Erycinidae, Mont- acutidae and Galeommatidae with special reference to the cili- ary mechanisms. Journ. Mar. Biol. Assoc. U. K. 24: 549 - 587 Purcuon, R. DENISON 1958. The stomach in the Eulamellibranchia; Stomach Type IV. Proc. Zool. Soc. London 131: 487 - 525 Quay te, D. B. 1960. The intertidal bivalves of British Columbia. Brit. Col. Province. Mus., Dept. Educat. Handbook 17, 104 pp. printed by Don MacDiarmid Rerp, Rosert G. B. 1965. The structure and function of the stomach in bivalve Journ. Zool. 147: 156 - 184 SrasEK, CHARLES ROBERT 1963. Synopsis and discussion of the association of ctenidia and labial palps in the bivalved Mollusca. The Veliger 6 (2): 91-97; 5 text figs. (1 October 1963) molluscs. Vol. 12; No. 1 THE VELIGER Page 53 Observations on Pervicacia tristis (DESHAYES, 1859) and a Comparison with other Toxoglossan Gastropods W. B. RUDMAN Department of Zoology, University of Auckland New Zealand (5 Text figures) INTRODUCTION THE TOXOGLOSSAN PROSOBRANCH MOLLUSCS are a group of specialised carnivores typified by a powerful neurotoxic secretion and harpoon-shaped radular teeth. The most studied family is the Conidae with work by Koun, CrEr- NoHorsky and others. The cones studied so far are all active selective predators, catching molluscs, worms and fish (Koun, 1959, 1956, 1955 - 1956). This family is not present in New Zealand, but the toxoglossans are repre- sented by the Turrids, which are generally uncommon and of small size, and the terebrid-like genus Pervicacia which is also reported from Southern Australia and Japan. The animal investigated is Pervicacia tristis (DESHAYES, 1859), a member of the infauna of silty sand banks at low water. Specimens were collected on the east coast, north of Auckland at the Whangateau Harbour and at the mouth of the Wade River. This animal lives just below the sur- face of the sand, and often is found under small mounds. Pervicacia lives in association with two tube worms, Owenia fusiformis CutajE, 1844 and Axiothella quadri- maculata AUGENER, 1914, and the molluscs Marginella pygmaea Sowersy, 1846, Paratrophon stangeri (Gray, 1843), Zeacumantus spp., and Baryspira spp. Accompa- nying these species is a small cumacean crustacean, prob- ably of the genus Diastylis, which Pervicacia could pos- sibly feed on. The animals collected refused to eat in captivity and the gut contents were unrecognisable. The animals were usually examined alive and dissected under a binocular microscope. For histological and ana- tomical investigation animals were fixed in Bouin’s fixa- tive and the sections cut were stained with either Weigert, van Giesen or Mallory Heidenhain stains. EXTERNALS — SHELL anp BODY Pervicacia tristis has a slender auger-shaped shell at- taining 20 mm in height and 6 mm in width. Few animals, however, reach this size. The coiling is dextral and radial ribbing is often present, sometimes being very pronounced. There is a horny operculum which fills the aperture when the animal retracts. The body is translucent, with many small white blotches showing under the surface formed by a granular secretory substance found throughout the foot and mantle regions. The mantle cavity is wide and extremely deep, water being drawn into it through the long inhalant siphon and tested by the large osphradium before running over the gills and passing out through an exhalant groove. The large brown bipectinate osphradium lies on the extreme left of the mantle cavity. To the right of this organ is the long monopectinate ctenidium, each lamina being triangular with one side being fixed to the mantle, ex- tending to the back of the mantle cavity. The genital duct opens also on the right, near the mantle edge in the female, and into the penis in the male. To the left of this organ is the rectum opening by a small anus. Between the long black rectal gland and the ctenidium is the large hypobranchial gland which produces a reddish purple secretion. There are neither eyes nor tentacles. The sexes are separate, the female duct ending in a large muscular ring and the male duct in a long flat penis. The lack of ; val Page 54 THE VELIGER Vol. 12; No testis kidney digestive gland vesicula seminalis oe intestine prostate gland anus penis seminal duct Vol. 12; No. 1 THE VELIGER Page 55 eyes and tentacles, the large osphradium and the increase in activity at night suggest that Pervicacia is nocturnal, locating food by chemosensory means (Figure 1). ALIMENTARY CANAL On the ventral surface of the “head” or “snout” is an opening, bordered longitudinally by a pair of muscular lips, which forms the apparent mouth. This opening leads into an anterior cavity which encloses the distal region of the proboscis bearing the true or inner mouth. The “snout” region, as is discussed later, is probably homologous with the pseudoproboscis of the terebrids (Figures 1, 4 P). The walls of the anterior cavity have a simple glandular epi- thelium overlain by a thin layer of transverse (or radial) muscle fibre. This is surrounded by a layer of muscle and connective tissue. In Hastula cinerea (Born, 1780) an “anterior tube” has been described, which when everted, corresponds to this region (Marcus & Marcus, 1960). In all specimens, whether alive or preserved, this region was always extended and appeared incapable of with- drawal. The buccal tube, or proboscis, which is only at- tached to the body wall by a few small muscles, is wide and highly muscular. Underlying the simple epithelium lining the lumen, is a thin layer of longitudinal muscles, followed by an ordered array of circular and transverse (or radial) muscle blocks. On the floor of the buccal tube is the odontophore, bearing a radula with two rows of simple triangular teeth (formula 1:0°0-0:1). The radular sac is short. Odontophoral cartilages are present, contradicting FRETTER & GraHAm’s (1962) statement that these have been lost in the Toxoglossa. The cartilag- inous blocks are moved by two well-developed muscles, M, and M2. When M, contracts and M: relaxes, the odon- tophore rocks forward and when M, is relaxed and M2 contracts, the cartilage rocks backwards (Figure 4 S). The apparently single salivary gland runs forward, splitting in two. The ducts from each lobe join, forming a common duct which enters the buccal tube near the mouth (Figure 4 P). The oesophagus recurves sharply twice, immediately behind the buccal tube, and then passes through the nerve ring. The lining at the anterior end of the oesophagus is ciliated and slightly folded, while further back the folding increases and the layer of longi- (<— on facing page) Figure 1 Pervicacia tristis (DESHAYES, 1859) Male, with mantle cavity opened tudinal muscle is replaced by a larger one of circular muscle. It is difficult to demarcate the transition from oesophagus to stomach, but the stomach can be distin- guished by heavier foldings of its wall. The gut wall here contains odd groups of globules staining bright red with Mallory Heidenhain and there is a thick layer of circular muscle. Two large ducts leave the digestive gland, merging to enter the stomach by a single opening. The histology of the digestive gland is similar to that of some stenoglos- sans described by FRETTER & GRAHAM (1962). The intestine can be divided into two regions. Near the stomach, red staining areas of granular cells are abundant in the intestinal wall. The diameter of the lumen of the intestine increases, almost all the folding disappears, and the wall becomes very thin. This region of the intestine is heavily ciliated and is the widest region of the alimen- tary canal. The pallial or distal region of the intestine is quite different. Near the back of the mantle cavity, the intestine narrows and becomes triangular in cross-section, the wall having large areas of red-staining granules. It has no musculature and runs through the mantle as a narrow, thick-walled, folded tube. It opens near the edge of the mantle cavity and is followed down the mantle by the rectal or anal gland (Figures 1, 3B). REPRODUCTIVE SYSTEM The ovary is a lobulated organ overlying the digestive gland in the top whorls of the body. The ova stain grey with Weigert, van Giesen stain. Part of the ovary is packed with bright yellow staining oocytes. The genital duct opens into the mantle cavity just behind the anus and is modified into several specialized regions: albumen gland; ingesting gland; capsule gland; and glandular vestibule. The ovarian duct, leading from the ovary to the albumen gland, is comparatively short, and is lined with a simple epithelium. From it is a duct to the pericardial cavity. The albumen gland has greatly folded walls, lined with secretory and ciliated cells. Below the albumen gland is the capsule gland (Figure 2 U). At the junction of the two, a duct leads off to the “ingesting gland.” The capsule gland is a large secretory region in which the duct has become extended to form a narrow dorso-ventral slit running forward in the mantle to open anteriorly into a large distensible vestibule with folded muscular walls (Figure 3B). This vestibule is a long muscular groove opening into the mantle cavity. The muscular opening of the groove could be considered the vagina. There is no bursa copulatrix. The length of the penis and the fact that it opens at its tip suggests that this organ enters the capsule gland Page 56 THE VELIGER Vol. 12; No. 1 testis ves. sem. prostate gland nucleus ®) iduct i uc ® albumen gland cap. gl. x st IK

Three-dimensional diagram showing completed polyhedron encompassing all length: height:depth combinations of larval Montacuta percompressa and two-dimensional graphs of height: length and length:depth. Base planes are shown for length 115» and at 25 intervals of length from 150 to 375 p. Vol. 12; No. 1 THE VELIGER comparisons with other sets of measurements are limited. An alternative method, multiple regression analysis, would provide a meaningful statistical statement, but could not be used if the variates do not follow a multivariate normal distribution where linearity of regression is requisite. Each set of measurement data for any species of bivalve larvae may havea characteristic polyhedron graph- ically distinguishable from other polyhedra. Similarly, averages and ranges may be peculiar to each set. If polyhedrons are determined for a sufficient number of species computer identification of planktonic larvae may be possible. We would like to express our appreciation to Mrs. Jane S. Davis for preparing the illustrations necessary for this paper. LITERATURE CITED CHANLEY, PAUL 1969. Larval development of the coquina clam, Donax vari- abilis, Say, with a discussion of larval hinge structure in the Tellinacea. Bull. Mar. Sci. (in press) Page 83 Page 84 THE VELIGER Vol. 12; No. 1 Notes on the Mitridae of the Eastern Pacific II] The Genus Thala, with the Description of a New Species BY GALE G. SPHON Los Angeles County Museum of Natural History, Los Angeles, California 90007 (Plate 6; 2 Text figures; 1 Map) AMONG THE ALLAN Hancock FouNnpATIoN gastropods that are on loan to the Los Angeles County Museum of Natural History and in material at the California Aca- demy of Sciences is an undescribed species of the family Mitridae from the Galapagos Islands. The morphological characteristics of this form indicate that it should be placed in the genus Thala H. & A. ApaMs, 1853. I would also place two other Eastern Pacific species, Mitra grati- osa REEVE, 1845, and M. solitaria C. B. Apams, 1852, in Thala. Thala was used for some Eastern Pacific members of the Mitridae (Dati, 1921; Oxtproyp, 1927), but was dropped in favor of Mitromica Berry, 1958. However, I regard the latter as a synonym for reasons that are discussed later in this paper. Thala H. « A. Apams, 1853 Thala H.« A. Apams, 1853, p. 178 (as a subgenus of Mitra). Type species by S.D., CossMann, 1889: Mitra mirifica Reeve, 1845a. Recent, Capul, Philippine Islands. REEVE, 1845b, Conch. Icon. plt. 34, spec. 277 Micromitra BELvarpi, 1888, p. 147. Type species by S.D., Coan, 1966, Micromitra taurina BeLuarpi, 1888. Middle Miocene, Europe Mitromica Berry, 1958, p. 94. Type species by O. D., Mitra solitaria C. B. ApaMs, 1852 DISCUSSION Thala is a genus of small species that can very roughly be divided into 3 groups, but the groups are far too indis- tinct to form subgenera. The first group has a recurved canal and includes the type species T: mirifica (REEVE, 1845) and such species as T: recurva (Reeve, 1845) and T. todilla (Micuets, 1845). Unfortunately, the radula of no member of this group has been illustrated. The second group is intermediate, with a slightly re- curved canal; it includes such species as Thala cernica (Sowerby, 1874), T. milium (Rutve, 1845), and T. soli- taria (C. B. Apams, 1852). The third group has a more truncate canal and includes Thala floridana (Daut, 1884), T. gratiosa (REEVE, 1845), and T: ogasawarana (Pitssry, 1904). All the radulae of the genus Thala that have been figured (McLean, 1967; Crernonorsky, 1966; Hane, 1943; and Tues, 1931) seem to belong to this group. Berry’s diagnosis of his taxon, Mitromica, was based on what is actually Thala gratiosa although he cited as the type species Mitra solitaria. Mitromica must remain with the species named as type, whatever BErry’s concept of Mitra solitaria. THIELE (1931) considered Thala to be a subgenus of Pusia, based on the 3 prominent cusps of the rachidian plate and the sickle-shaped lateral plates. However, Thala has several morphological features not shared by Pusza. The most significant of these are the prominence of the lirations on the inner side of the labrum, the presence or suggestion of an anal sulcus, cancellate sculpture, and a subsutural band. These characters, as well as some features of the radula, make a distinguishable genus. Both Daty (1921) and Otproyp (1927) listed Mitra orcutti Dat, 1920, in the “section” Thala of the genus Mitra. However, McLEan (personal communication) has examined the holotype and finds the species to be a syno- nym of the turrid Mitromorpha gracilior (Tryon, 1884). Thala gratiosa (Reeve, 1845) (Plate 6, Figures 1, 2) Mitra gratiosa Reeve. 1845, p. 53 Thala gratiosa (REEVE, 1845). - Tryon, 1882, p. 161 Mitra (Thala) solitaria C.B. Apams, 1852. - Datt, 1921, p. 87. - Oxproyp, 1927, p. 173. - Smiru, 1944, p. 33 Vol. 12; No. 1 Mitromica solitaria (C. B. ApaMs, 1852). - Berry, 1958, p. 44. - McLean, 1967, p. 58, text fig. 1 (radula) Mitra (Mitromica) solitaria C. B. ADAMS, 1852. - Keen, 1958, p. 428 Mitra (? Costellaria) nodocancellata Stearns, 1890, p. 213 Diagnosis: Shell small for the genus, adult specimens to 10 mm in length; black; ovate; sculpture cancellate; canal truncate; aperture narrow; labrum lirate within; anal sulcus becomes more pronounced with age. Type Material: The holotype of Mitra gratiosa REEVE, 1845, is in the British Museum (Natural History). Type Locality: Six fathoms, Galapagos Islands, Ecuador, Hugh Cuming, collector. The holotype of Mitra nodocancellata Stearns, 1890, is in the United States National Museum (no. 55490). Type Locality: Gulf of California, W. J. Fisher, collector. Distribution: Thala gratiosa has been reported as Mitra solitaria from Point Loma, San Diego, California (Dat, 1921; Oxproyp, 1927; SmirH, 1944; Keen, 1937). Ap- parently this is the northern limit of its distribution and it is rare in the San Diego area, for it has not been reported from there in over 30 years. It is unknown between San Diego and the Cape San Lucas area in Baja California. The species is found throughout the Gulf of California and south to Panama and the Galapagos Islands. I have examined approximately 300 specimens of this species and while I do not consider it rare, it certainly is not a common species. Discussion: Dati (1921) was apparently unaware of Thala gratiosa from the Galapagos Islands when he placed Mitra nodocancellata in synonymy with T. solitaria, be- cause he cites the photograph of STEARNS’ (1890) holo- type as an example of T. solitaria. Apparently this error has been perpetuated for 2 reasons: 1) ‘Thala gratiosa was originally described from the Galapagos Islands and never reported from the mainland, and 2) it was de- scribed as having a brown shell while T. solitaria was described as having a black one. This would indicate that Cuming had dredged a dead specimen, for T: gratiosa usually bleaches to a dark rust or brown color after the animal has died. Thala gratiosa has an Atlantic analogue in T. floridana (Da, 1884). The main differences between the 2 spe- cies, other than distribution, is that T: floridana is smaller and proportionally wider. Thala solitaria (C. B. ApAMs, 1852) (Plate 6, Figure 3) Mitra solitaria C.B. ADAMS, 1852, p. 44. - TuRNER, 1956, p. 87, plt. 5, fig. 1 (holotype) THE VELIGER Page 85 Thala solitana (C.B. Apams, 1852). - Tryon, 1882, p. 160, pit. 47, fig. 358 Mitromica solitaria (C. B. ApamMs, 1852. - Berry, 1958, p. 44 (type designation only) Mitra (Mitromica) solitaria C. B. ApAMs, 1852. - Keen, 1958, p. 429, fig. 646 (figure on the right, after Turner, 1956) Not “Mitra solitaria” of other authors Diagnosis: Shell relatively large for the genus, adult spe- cimens to 17 mm in length; black, occasionally with white nodes; sub-attenuate; sculpture cancellate; canal slightly recurved ; aperture moderately narrow; labrum lirate with- in; anal sulcus becoming more pronounced with size and age; a subsutural band present. Type Material: The holotype is in the Museum of Com- parative Zoology at Harvard University, no. 186351. Type Locality: Panama, C. B. Adams, collector. Distribution: The present report on the distribution of Thala solitaria is based on 10 specimens that show it to occur from Los Arcos, Banderas Bay, Jalisco, Mexico, to the Galapagos Islands. With the exception of the holotype, one specimen from Panama in the Santa Barbara Museum of Natural His- tory (cat. no. 06291), and 2 specimens from the Galapa- gos Islands in the California Academy of Sciences (loc. no. 27221), all other specimens examined are in the Los Angeles County Museum of Natural History. Discussion: Thala solitaria is evidently rare and closely related to T: gratiosa. As in that species empty shells bleach to a dark rust or brown color. The 2 species have a very similar habitat. ADAMS (1852) said that T: solitaria was found “... Under stones near low water mark...”, and when T: gratiosa is found intertidally it is always found under rocks. Thala jeancateae SPHON, spec. nov. (Plate 6, Figure 4) Diagnosis: Shell medium sized for the genus, white with brown markings, sub-acuminate; sculpture cancellate; canal slightly recurved; aperture moderately narrow; lab- rum lirate within; anal sulcus and subsutural band present. Description of Holotype: Shell medium sized for the genus, length 9.4mm, width 3.8mm, length of aper- ture 2.4 mm; sub-acuminate; whorls 9; nucleus and first 3 postnuclear whorls smooth; sculpture of the remaining 6 of sharply incised spiral and axial lines giving a nodose- cancellate appearance; anal sulcus evident but faint; labrum thin with denticulations within; columella with 4 strong plaits; anterior canal short, slightly recurved; sub- sutural band set off by a row of nodose-cancellate bead- Page 86 ing; color white with lines and irregular smudges of brown, the base of a more intense brown; aperture, co- lumella, and plaits porcelain-white. Type Material: The holotype is in the Los Angeles County Museum of Natural History Invertebrate Zoology Type Collection (LACM-AHF 1202) and was dredged by the Allan Hancock Pacific Expedition of 1934 on January Figure 1 Radula of Thala jeancateae SPHoN, spec. nov. The rachidian plate and one lateral plate 15, 1934, station no. 155-34. There is one paratype (CAS 13204) and one hypotype in the California Academy of Sciences. The paratype is a dead specimen from the type locality, but no depth is given. The hypotype is a Pleisto- THE VELIGER Vol. 12; No. 1 cene fossil from James Island in the Galapagos Islands (CAS loc. no. 27255). Type Locality: 50-60 fathoms off Tagus Cove, Aibe- marle Island, Galapagos Islands, Ecuador (0°16'45”S, SI 22/520) Name: The name of this species, jeancateae, has been chosen in honor of Jean-Cate (Mrs. Crawford N.) for her work with the Mitridae. Discussion: ‘Thala jeancateae can readily be distinguished from the 2 other Eastern Pacific members of the genus, T: gratiosa and T. solitaria, by the color. Thala jeancateae is white with brown streaks and smudges, while T: gratiosa and T: solitaria are black. 'Thala jeancateae differs in shape from T.solitaria, being more sharply attenuate, and from T: gratiosa in being acute rather than obtuse. The blunt spire of T: gratiosa also serves to separate it from the other 2 species which have sharp spires. The sculpture on all 3 species is cancellate. The sculp- ture in Thala jeancateae and T. solitaria is very similar but differs from T. gratiosa in that both the spiral and axial ribs are wider and more nodose at their juncture. In T: gratiosa the sculpture is less nodose and the spaces be- tween the ribs give the impression of forming squarish pits. The radulae clearly separate 2 of the 3 Eastern Pacific species of ‘Thala. (Unfortunately, I have not been able to obtain the radula of T: solitaria). 'Thala jeancateae has the typical three-cusped rachidian plate (see Text figure 1) indicated by CERNoHoRSKY (1966, p. 120) for T. ogasawarana (PitsBry, 1904) and T: simulans (von Mar- Explanation of Plate 6 Figure 1 Mitra gratiosa REEVE, 1845 Holotype. Galapagos Islands, Ecuador. Length 11.5 mm Photograph courtesy of British Museum (Natural History) Figure 2 Mitra nodocancellata STrEaRNs, 1890 Holotype. Gulf of California, Mexico. Length 10mm Photograph courtesy of Dr. James McLean, Los Angeles County Museum of Natural History Figure 3 Mitra solitaria C. B. Apams, 1852 Holotype. Panama. Length 0.68 inches Photograph courtesy of Dr. Ruth Turner, Museum of Comparative Zoology, Harvard University Figure 4 Thala jeancateae SPHON, spec. nov. Holotype. 50 - 60 fathoms off Tagus Cove, Albemarle Island, Galapagos Islands, Ecuador. Length 9.4mm. Photograph courtesy of Mr. Lawrence Reynolds, Los Angeles County Museum of Natural History Tue VELIGER, Vol. 12, No. 1 [SproNn] Plate 6 Figure 1 Figure 2 Figure 3 Vol. 12; No. 1 THE VELIGER Page 87 San Diego Rancho £1 Tule Carmen Island Los Angeles Bay San Luis Gonzaga Bay San Luis Island Puertecitos Agua Chale Guaymas Mazatlan Banderas Bay Cuastocomate Bay San Juan Del Sur KILOMETERS * 0 50100 1000 Corinto ri 0 50 100 500 Bahia Honda STATUTE MILES Balboa Borgona Island Port Utria Barrington Island Localities: Thala gratiosa (REEVE, 1845), stations 1 to 19 Thala jeancateae Spuon, spec. nov., station 19 Thala solitaria (C. B. ApaMs, 1852), stations 11, 12, 16-19 Page 88 Figure 2 Thala gratiosa (REEVE, 1845) (after McLEAN, 1967) The rachidian plate and one lateral plate TENS). Thala gratiosa (figured by McLean, 1967, as Mit- romica solitaria) is more aberrant (see Text figure 2) with 7 cusps on the rachidian plate. ACKNOWLEDGMENTS I am indebted to the many people and institutions who allowed me to examine their collections of this group. I am particularly indebted to Dr. Rudolf Stohler and Mrs. Jean Cate for their help and understanding, Dr. James McLean and Dr. Eugene Coan for critical reading of the manuscript, and Mr. James Lance for his mounting and illustration of the radula of Thala jeancateae. LITERATURE CITED ApaMs, CHARLES BAKER 1852. Catalogue of shells collected at Panama, with notes on synonymy, station, and geographical distribution. Ann. Lyc. Nat. Hist. New York 5: 229 - 344 (June) ; 345 - 548 (July) ApaMs, Henry « ARTHUR ADAMS 1853. The genera of Recent Mollusca arranged according to their organization. London (John van Voorst) 3: i-xl+ 1 - 484 Bexxarot, Luict 1888-1889. I molluschi dei terreni Terziarii del Piemonte e della Ligura. Part 5: Mitridae Mem. Acc. Sci. Torino (2) 38: 79-166; plts. 1-2; 257-326; plts. 3-4 [1888, possibly 1887]; (2) 39: 145-194; plts. 5-6 [1889, possibly 1888]. Also issued separately. THE VELIGER Vol. 12; No. 1 Berry, SAMUEL STILLMAN 1958. | West American molluscan miscellany. - II. in Malacol. 1 (16): 91-98 CERNOHORSKY, WALTER OLIVER 1966. A study of mitrid radulae and a tentative generic ar- rangement of the family Mitridae. The Veliger 9 (2): 101 to 126; 47 text figs. (1 October 1966) Coan, EucENE VICTOR 1966. | Nomenclatural units in the gastropod family Mitridae. The Veliger 9 (2): 127 - 137 (1 October 1966) CossmMaNnn, ALEXANDRE EpouARD MAUurRICE 1899. _ Essais de paléoconchologie comparée 3: 1 - 201; 8 plts. Paris Dati, WiLt1AM HEALEY 1921. Summary of the marine shellbearing mollusks of the northwest coast of America, from San Diego, California, to the Polar Sea... . Bull. U. S. Nat. Mus. 112: 1 - 217; plts. 1-22 (24 February 1921) Hasse, TaDASHIGE 1943. On the radulae of Japanese marine gastropods (I). Japan. Journ. Malac. 13 (1-4): 68-76; plts. 3-4 Keen, A. Myra 1937. An abridged check list and bibliography of West North American marine mollusca. Stanford Univ. Press, Stanford, Calif. pp. 1-88 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford Univ. Press, Stanford, Calif. (5 December 1958) McLean, JAMES HAMILTON 1967. Note on the radula of Mitromica Brrry, 1958. The Veliger 10 (1): 58; 1 text fig. (1 July 1967) O.proyp, IpA SHEPARD 1927. The marine shells of the west coast of North America. 2 (1): 297 pp.; 22 plts. Stanford Univ. Press, Stanford, Calif. ReEEvE, LovELL Aucustus 1845a. Descriptions of eighty-nine new species of Mitra, chiefly from the collection of H. Cuming, Esq. Proc. Zool. Soc. London 13: 45 - 61 (September 1845) 1845b. Conchologia Iconica. Monograph of the genus Mitra. 10: plts. 1 - 39 SmituH, MAxwELL Leafl. 1944. | Panamic marine shells. 912 figs. STEARNS, ROBERT EDWARDS CARTER 1890. Scientific results of explorations by the U.S. Fish Com- mission steamer Albatross. No. XVII. - Descriptions of new West American. land, fresh-water, and marine shells, with notes and comments. Proc. U.S. Nat. Mus. 13: 205 - 225; plts. 15-17 THIELE, JOHANNES 1929. | Handbuch der systematischen Weichtierkunde. Jena, Gustav Fischer, 1929-1935; 1- 1154; 893 text figs. Tryon, GeorcE WASHINGTON, Jr. 1882. | Manual of Conchology. Monograph of the Mitridae. 4: 106 - 200; pits. 32 - 58. Philadelphia. Winter Park, Florida, 127 pp. Vol. 12; No. 1 THE VELIGER Page 89 Cuttlebones on the Beach at Galveston BY HAROLD W. HARRY AND SELMA F SNIDER Marine Laboratory, Texas A&M University, Galveston, Texas 77550 (3 Text figures) “To him who in the love of nature holds Communion with her visible forms, she speaks A various language for his gayer hours She has a voice of gladness, and a smile And eloquence of beauty; and she glides Into his darker musings with a mild And healing sympathy, that steals away Their sharpness ere he is awake.” THESE LINES FROM William Cullen Bryant’s ‘““Thanatop- sis’ are particularly appropriate to the pass-time of beach combing, for no matter how barren a beach may be, or how frequently one has combed it, there is always a refreshing release from the cares of the day. Not in- frequently, there is something new to excite the imagi- nation, which may speak to each a “various language.” One such occasion was experienced by the junior author in January 1968. When combing the beach at 61" Street in Galveston, she came upon a cuttlebone. Shortly she en- countered Mrs. Rosalie Schreiber, who had picked up six more and neglected several others. Neither person had ever seen them on the beach before, although both have been ardent beach combers here for many years. Inquiry among devoted beach combers of the Galveston Shell Club revealed only one other cuttlebone. Mrs. Louise Beeman had found one some time previously. Her speci- men is larger than the ones found by Mrs. Snider and Mrs. Schreiber, and too worn to be diagnosed much more specifically than to say that it is a cuttlebone. Where did they come from? Are there cuttlefish (Sepia) in the western Atlantic? If they floated here from some distant shore, from which one, and are cuttlebones suffi- ciently diagnostic to determine the species of cuttlefish? Perhaps they were thrown here by someone who had gotten them elsewhere? Very occasionally marine objects not indigenous to this region are found on the beach at Galveston, probably thrown there by some irresponsible person. West coast abalone shells, also Cypraea moneta and Melongena corona have on occasion been found, and doubtlessly came from the shell shops along the sea wall. The local pet shops sell cuttlebones, which pet owners give to caged birds to sharpen their beaks. All that we have seen in the pet shops are almost twice as long as the ones found on the beach in January 1968. They were moreover carefully trimmed with a knife along their lat- eral margins and ventral surface. That the beach speci- mens were casually discarded seems unlikely. The margins of the beach specimens were not trimmed, but the ventral surface was slightly worn. They had no marine growths (barnacles, etc.) on them, and all had a strong odor recalling that peculiar to spoiled squid. This suggests that they did not float in the sea very long. But Sepia is reputedly absent from the western Atlantic, and indeed all shores of the American continents (HoyLe, 1886, p. 223; Lane, 1962, p. 29). Several experienced shrimp fishermen of Galveston to whom we showed a pic- ture of the cuttlefish said that they had never seen it in these waters. We have not found cuttlebones listed in any of the numerous faunal lists of mollusks based chiefly on shore collecting in the western Atlantic. Such lists are not very critical in differentiating between species which actually live in an area, and those which are adventitious, for they frequently list Spzrula, a shell common on beaches, but known to live only between 200 and 1500 m depth (BruuN, 1943). In 1968, the senior author found no Page 90 cuttlebones in the collection of the U.S. National Muse- um from beaches along the shores of the Americas, but beach specimens from other shores were well represented. Along the beaches of England, North Africa, and the Indian Ocean, cuttlebones are said to be common. ForBES & Haney (1853, vol. 4, p. 238) noted that “The common cuttlefish (Sepia officinalis L.) is one of the most beauti- ful and curious of British mollusks, but although its bone, or shell, is frequently cast up on all our sandy shores, the creature itself is rarely seen and seldom taken.” Lane (1962) noted that tons of cuttlebones are exported yearly from Tunisia, apparently gathered from the beach, al- though he is not explicit. Of the numerous new species of Sepia named since Hoye (1886) summarized the known Recent Cephalopoda, several have been described from cuttlebones cast upon beaches. Thus, SmirH (1916) de- scribed four new species of Sepia from beach cuttlebones in South Africa, and WinckworTH (1936) one species, based on two cuttlebones found at Madras, India. There is one recent report of beach cuttlebones in the western Atlantic. ErpMAN (1957) reported finding several at Anegada, the northeasternmost of the British Virgin Islands. They were found high up on the beach, had been worn by the sea, and “one or two had a greenish tinge in cross section, indicating perhaps some algal growth.” One specimen was sent to Dr. Gilbert Voss, who identified it as Sepia officinalis. Dr. Voss suggested that it had floated across the Atlantic, and noted that he had several speci- mens from the east coast of Florida, all of which showed evidence of being at sea for a long time. ERDMAN noted that he had never found cuttlebones in Puerto Rico, where he has spent much time beach combing. A very early report of Sepia in the Caribbean has been discounted by Hoyte (1886) as too vague to be useful. But, as p’OrBIGNY was an astute observer of mollusks, and a specialist in cephalopods, his statement on the matter is worth quoting in full (p’Orsicny, 1841, p. 33, translated from the French) : “No. 8. Cuttlefish of the Antilles “Sepia antillarum d’Orb. We designate, under this purely provisional name, the cuttlefish indicated by Browne [footnote: The natural history of Jamaica, p. 386] as occurring at Jamaica. It is rather common at the other Antilles, and we have before our eyes an example from Mar- tinique preserved in the Museum of Paris, under the improper name of Sepia Orbigniana Fer. After having examined it with care, although someone had _ removed the ossicle from it, it is easy for us to recog- nize that this is not Sepia Orbigniana, but indeed a species one no longer may place near Sepia vulgaris, from which by the poor state of preservation and the THE VELIGER Vol. 12; No. 1 absence of the ossicle we are prevented from recog- nizing the identity or the specific differences. “However, we do not believe that we should pass in silence this (p. 34) species of the Antilles, but in order to arrive at a better understanding of it, arouse attention in this respect.” We have not seen thie rare book by BRowNE (1756) which p’OrBicNy cites as recording the presence of the cuttlefish in Jamaica. Nor can we account for p’Orsic- Ny’s comparison of Antillean cuttlefish with Sepia vul- garis, for no such trivial name seems to have been used in the genus since 1758. Browne seems not to have used the name. Mr. Thomas H. Farr of the Science Museum of the Institute of Jamaica, sent a copy of BROowNeE’s de- scription, evidently taken from the second edition. BROWNE did not give an illustration of it. The description (BRowNE, 1789 edition, page 386) is as follows: “SEPIA 1. Vagina subovato-truncata. “THE INK or SCUTTLE-FISH “This insect is frequent enough about Jamaica, but most common on the north side of the island. It is composed of a firm transparent sheath which in- cludes the greatest part of an adherent but softer gelatinous mass, furnished with a great number of tentaculae of different sizes and forms. It is curious to see how readily this creature discharges its ink on the approach of danger, to hide itself in the coloured fluid: but the juices discharged on such occasions, are not only black and thereby sufficient to protect the creature by giving a tincture to and thickening the water about it; they are also bitter and clammy which must probably render them either pernicious to the gills, or hurtful to the eyes of all other fishes.” Mr. Farr also wrote, “We do not know of any speci- mens of Sepia having been found in Jamaica, however cuttlebone has been found at Morant Point at the eastern end of the Island. Mr. Lewis, the Director of the Institute of Jamaica, tells me that his daughter used to collect it there and bring it home for her budgerigars of which she had a considerable number. So cuttle bone does not seem to be rare on Jamaican Beaches.” Dr. Ivan Goodbody of the Zoology Department, Uni- versity of the West Indies, at Kingston, Jamaica, confirms Mr. Farr’s account, writing to us: “I also have collected cuttle bones at Morant Point washed up on the shore, but in spite of doing some extensive Isaacs-Kidd trawling and other fishing off the eastern end of the island none of us have ever collected a living Sepia. As the cuttle bones are very buoyant and resilient, they could be carried to Jamaica from a very long way away. I would therefore hesitate to suggest that the cuttle bones which we find come from local animals.” Vol. 12; No. 1 Still, even supposing that cuttlefish do not live in Carib- bean waters, it is of interest that the sepions float to Jamaica with some frequency, and have never been found in Puerto Rico. The case of cuttlebones on New Zealand beaches is noteworthy. Sutrer (1913) listed 3 records of Sepia apama Gray from there, each based on a single sepion from the beach. Almost 50 years later, PowELL (1962, p. 71) noted that cuttlebones and shells of the chambered Nautilus occasionally wash ashore on those islands, but he did not think either cuttlefish or nautili lived there. His list (op. cit.,p.126) of species of Sepia cuttlebones found in New Zealand has only S. apama and S. plangon, both known to live in Australia, some 2000 miles west- ward. Cotton & Goprrey (1940) list 11 species of Sepia from South Australia, including those two, and 29 others found elsewhere around the continent. It is strange that cuttlebones of only two of the many species in Australia have floated to New Zealand. Perhaps it is a matter of differences in living habits of the cuttlefish, or intrinsic differences in the cuttlebones, or perhaps it is merely a failure to record the cuttlebones from the shores of New Zealand. ALLEN gives an interesting account of cuttlefish behavior in Australian waters and the cuttlebones on the beaches. She also notes that the sepion of Amplisepia verreauxt ROCHEBRUNE, which is a senior synonym of Sepia apama Gray, may reach a length of 45cm, or 18 inches. There is one further bit of evidence that Sepia does occur in the western Atlantic. Oxtverra (1940) named a new subspecies from Brazil, Sepia officinalis jurajubai. Her description is too meager to be of much use in differ- entiating populations of this difficult species complex. In the same year, Apam (1940) proposed that several nom- inal species of larger cuttlefish of the eastern Atlantic are merely subspecies of §. officinalis, and these can be in part distinguished by their cuttlebones. Oxtverra did not de- scribe or illustrate the cuttlebone of the specimen she examined, but from her photographs it is evident that she had a whole animal and that it is similar to S. off- cinalis. Could it be that Ottvemra’s specimen had migrated across the Atlantic? If Sepia lives in the western Atlantic, why is its presence so rarely reported? Perhaps it does live here, but in situations which are little frequented by fisher- men using suitable gear to catch them. ABEL (1916) made a study of the habits and behavior of living cephalopods for a better understanding of fossil species, but he merely notes of Sepia that it lives near the bottom, over sand. ABEL, ADAM, and other writers say that §. officinalis is migratory, spending most of the year in deeper water, THE VELIGER Page 91 but coming to shore during the breeding season, in the warmer months. Tryon’s (1883, vol. 2. p. 40) account is worth quoting: “According to Verany, this animal (S. officinalis) prefers rocky localities in the Mediterranean, where it is fished by means of a dredge called a balancelle, and is also taken at night with the trident. During the month of March the fishermen use a living female Cuttle fastened to a rope, or an imitation of one formed of wooed, and made attractive to the male sex by being ornamented with bits of glass; this latter enveiglement is called by the Sicilians a fumedda, and fishing with either of them is very productive and amusing, especially on a moonlight night . ... Their flesh is esteemed and abounds in the Italian markets at all seasons of the year.” Lane (1962, pp. 169ff) describes a fishing method of baited traps used in the Mediterranean. These are made of wicker baskets, attached along a weighted line. He also repeats the account of fishing with female cuttlefish and artificial lures. From the above descriptions, we may suppose that if Sepia lives near Galveston, it is likely to be around the rocky reefs that occur beyond the 10-fathom zone, some 30 miles offshore. Those areas are not attractive to fisher- men using shrimp trawls, because of the danger of re“ ee Figure 1 Ventral view of the shell of Sepia mestus Gray. After Hoyze, (1886, p. 123) 1-Last loculus - 2-Chitinous margin of outer cone 3 - Striated area (margins of earlier loculi) ~ 4-Limb of inner cone 5 - Inner cone (a thin filet of calcareous matter) - 6- Spine Page 92 THE VELIGER Vol. 12; No. 1 Figure 2 Ventral view of a cuttle bone found at Galveston. 70 mm long tearing the nets. If the population of Sepia were small, the individuals alert but shy, they might not be easily taken. The cuttlebones of Galveston (Figures 2 and 3) seem to be all of one species; there is nothing very different from the specimens of Sepia officinalis ossicles sold in the pet shops, nor from descriptions and illustrations of that species in the literature. Figure 1 indicates the terms ap- plied to parts of a cuttlebone. Figures 2 and 3 were drawn by the junior author from the beach specimens of Galves- ton. Figure 3 Dorsal view of same cuttlebone shown in Figure 2 The outline is elongate oval, with the sides almost paral- lel throughout most of their length, and slightly sinuate about a fourth of the length from the hind end. The locular margins were too worn to note the pattern of their edges or the locular index (length of last loculus as percent of total length). The dorsal surface is covered by a thin sheet of shiny, transparent cuticle over its hind end, and the rest is uniformly, faintly roughened by short, transverse, closely spaced rugae. There is a shallow furrow, poorly defined, on each side of the midline, with a low medial ridge between them. In side view, the cuttlebone Vol. 12; No. 1 is almost flat. The spine is short and acute. The chevron markings on the ventral surface of the one drawn seem to be the bill print of some shore bird. Measurements (in millimeters) Length Width 70 22 (Figures 2, 3) 82 26 88 30 75 25 75 26 That there is much yet to be discovered concerning the mollusks, and particularly the cephalopods, of the Gulf of Mexico can scarcely be denied. We may further note that Voss (1956), in monographing the cephalo- pods of the Gulf, merely suspected the presence of Argonauta here, and had no specimens from the area. Several specimens with animal and shell were found in the stomach of the dolphin, Coryphaena, in the summer of 1966 by Mr. Jim Dailey, while fishing south of Freeport, Texas. To our knowledge, Argonauta has never been found alive in this area. Beach shells are much rarer than the literature indicates. At least, we have never found any in Louisiana or Texas. But Coryphaena knows where the paper nautilus lives, and how to capture it. WARMKE (1961) also reports the paper nautilus from a_fish’s stomach in Puerto Rico. Interesting in this respect is the case of the giant squids of the family Architeuthidae, monsters of 4m _ body length and more. These are known only from disabled specimens floating on the surface, or cast ashore, or dis- gorged by captured whales. Lance (1962) has a vivid account of battles between these squid and whales, noting that the squid may be the protagonist (see also VERRILL, 1882). Although giant squid are said to be cosmopolitan, the dearth of records of juveniles captured by trawling is striking, particularly if they are, as noted by Voss (1956, p. 138): “in all probability very poor or weak swimmers and not at all adapted for catching active prey. Indeed, they should fall easy victims to the sperm whale, their natural enemy.” ADDENDUM After this paper was written, Mr. William Wardle found two cuttlebones on the east end of Galveston Island, on 21 December 1968. These are about equal in size, but they are larger than the ones found nearly a year before. The larger one is 135mm long, 43mm wide, and 19mm THE VELIGER Page 93 thick. They are of the same species as those found earlier, and in even more perfect condition. There is no evidence of epibiota on them. A break in the inner cone of one shows a transparent material resembling cartilage filling its interior. The lower surface of both specimens was badly scarred and pitted by chevron markings, again suggesting these had been pecked by sea birds. The lower surface is thickest about one-fourth the length from the hind end, from which point it slopes forward in a gentle convex arch, and backward in a more pronouncedly concave excavation. The striated area begins at the thickest point of the sepion, and thus the locular index is about 75% of the length. Besides being larger, the Wardle specimens show two important anatomical differences from the smaller ones: (1) The dorsal surface has a thin, smooth cuticle along the posterior half of each margin, leaving a broad V-shaped area in the middle free of it. The apex of the V is nearly at the hind tip of the shell. Contrast the shallow V of the smaller specimen drawn in Figure 3, in which the dorsal cuticle is limited to the hind fourth of the shell. (2) There is no projecting spine, and the chitinous mar- gin of the outer cone seems to extend a little farther behind the calcareous part of the shell than in the smaller specimens. These differences probably represent changes during growth, rather than distinct species. The sculpture of the dorsal area is of small bosses and short vermiculate rugae, rather irregularly oriented and closely spaced. The Wardle specimens were dropped into alcohol when found. This method of preservation allows details to be seen much more clearly than in the smaller specimens, which were dried. LITERATURE CITED ABEL, O. 1916. Paldobiologie der Cephalopoden. Gustav Fischer, Jena; 281 pp. ApaM, W. 1940. Les races de la seiche commune (Sepia officinalis Linné). Bull. Soc. Zool. France 65: 125 - 131 ALLAN, Joyce K. 1950. Australian shells. Browne, PATRICK Georgian House, Melbourne; 470 pp. 1756. The civil and natural history of Jamaica: viii +503 pp.; 49 plts. (second ed. 1789: viii+490 pp.) Bruun, ANTON, Jr. 1943. The biology of Spirula spirula (L.). Dana Reprt. No. 24: 1 - 44 Cotton, BERNARD CHARLES & FRANK K. GopFREY 1940. The Mollusca of South Australia. Part II - Scaphopoda, Cephalopoda, Aplacophora and Crepipoda. Frank Trigg, Printer, Adelaide. pp. 315 - 600 Page 94 ErpMAN, DonaLp S. 1957. | Vagabond cuttlebones. Forses, Epwarp & SYLVANUS HANLEY 1848-1853. A history of British Mollusca and their shells. Van Vorst, London; 4 vols.; illustr. Hoy.e, WiLLiAmM Evans 1886. Report on the Cephalopoda collected by H.M.S. Challenger during the years 1873 - 76. Rept. Sci. Res. Voy. Challenger 1873-76. Zool. 16 (44): 1-245; 33 plts.; 10 figs. in text Lane, Frank W. 1960. Kingdom of the octopus. (1962 ed.), 287 pp. O.iverra, HELENA Paks DE 1940. Sobre dois cefalopodos da Guanabana. Agric. (Rio de Janeiro, Brazil) 10: 29 - 35 Orsicny, Atcipe DESSALINES D’ (1841) -1853. Mollusques, in Ramon de la Sagra, Histoire phy- sique, politique et naturelle de l’ile de Cuba. Paris (Arthus Bertrand) : 2 vols., atlas of 28 plts. PowELL, ARTHUR WILLIAM BADEN 1962. Shells of New Zealand. Whitcombe & Tombs, Auck- land, 4‘ ed., pp. 1 - 203; pits. 1-36; text figs. Nautilus 70 (3): 106 - 107 Pyramid Publ. New York Bol, Minist. THE VELIGER Vol. 12; No. 1 Smrrn, Epcar ALBERT 1916. | On the shells of the South African species of the Sepi- idae. Proc. Malacol. Soc. London 12: 20 - 26; plt. 2 Suter, HENRY 1913. Manual of New Zealand Mollusca. MacKay, Wellington, New Zealand, 1 - 1129; atlas of plates (1915) Tryon, GEORGE WasHINGTON, Jr. 1883. Structural and systematic conchology: an introduction to the study of the Mollusca 2. Philadelphia. pp. 1 - 430; pits. 23 - 91 VERRILL, ADDISON E. 1882. Report on the cephalopods of the northeastern coast of America. Ann. Reprt. U.S.Comm. Fish & Fisheries for 1879: 1 - 244; 46 plts. Voss, GrcBerT L. 1956. A review of the cephalopods of the Gulf of Mexico. Bull. Mar. Sci. Gulf and Carib. 6 (2): 85-178; 18 figs. WarRMKE, GERMAINE L, 1961. Brown paper nautilus recorded from fish stomach in Puerto Rico. Caribb. Journ. Sci. 1 (4): 142 [not seen] WINcKworTH, RONALD 1936. Marine Mollusca from South India and Ceylon. IV. A new Indian Sepia. pit. 4 Proc. Malacol. Soc. London 22: 16 - 17; Vol. 12; No. 1 THE VELIGER Page 95 A Revision of the Eastern Pacific Ovulidae BY CRAWFORD N. CATE 12719 San Vicente Boulevard, Los Angeles, California 90049 (Plates 7 to 10; 3 Maps) INTRODUCTION REcENTLY I was ASKED to identify some Simnia from the Gulf of California. During the identification of these species, much confusion was noted and it seemed that some attempt to clarify the nomenclatural status of them would be desirable. In examining the shells in private col- lections and West Coast Museums I observed that many remained unidentified while others were incorrectly iden- tified. In consulting the literature it soon became obvious that little work had been done with these shells in recent years, and what had been accomplished earlier gave no clear indication of the essential differences existing be- tween the species. An attempt will be made here to show how the shells of this group of species are distinctly separable from one another; the names of those that do not meet this requirement will be relegated to synonymy. A part of the eastern Pacific Ovulidae comprise a group of 10 species assigned to 3 genera: Jenneria, Simnia, and Cyphoma. An attempt will be made here to identify the species by means of specific morphological and color characteristics, employing the nomenclature proposed by ScuILpErR (1968) ; the species are illustrated and a limited locality list is provided to show the ranges of the species within the prescribed area and the manner in which some of these ranges overlap. DISCUSSION In the two west American species, Simnia loebbeckeana (Weinkaurr, 1881) and S. catalinensis (BERRY, 1916), the shells are, with few variations, ivory colored; in Cyphoma emarginata (SowErRBy', 1830) the shell is con- sistently off-white in color. In the other 7 species, however, color is a basis for confusion, particularly where the shell assumes the color of the host gorgonian upon which the species lives; these colors may vary from white to an intense deep purple-brown. There is one exception among them, however; in S. aequalis (SoweRBY", 1832), the yel- low color on white shells, and yellow-orange on the tinted specimens, constitutes a major point in the identification of the species. Some of the animals in Simnia, although having appar- ently identical shells, seem to vary in the color of the soft parts. It is generally assumed that simniids often take on the color of the gorgonians on which they live. In the sub-group Cyproglobinini ScuiLprEr, 1932, there is one accepted genus: Jenneria JoUSSEAUME, 1884. In the sub-group Simniini ScHiLpER, 1927, there are two accepted genera: Simnia Risso, 1826, and Cyphoma Ropinec, 1798. Neosimnia Fiscuer, 1884, has been rele- gated to synonymy with Simnia (ScuiLpeEr, 1968, p. 271) and therefore will not be used in this report. GENERIC KEY Cyproglobinini: Shells cypraea-form; surface finely stri- ate; dorsum nodulate Jenneria Simniini: Shells elongate; terminals usually short (shorter than in Volva Ropinc, 1798) ; anterior aperture less con- stricted, or not at all; transverse carina on dorsum absent. Outer lip narrow or sharply edged, inflected or reflected; with or without fossula Simnia Shell long, wide; terminals broad, rounded or subsquare; shell thickly, solidly constructed; central dorsal carina prominently elevated; a funicular, carinal twist on the adapical surface of the columella may be present Cyphoma (Jenneria and Cyphoma include but a single species each in the area covered by this report.) KEY to THE SPECIES or Simnia Smooth, glossy, without dorsal sculpture ..... loebbeckeana White, sharply upraised columellar carina along entire length of shell rufa Page 96 THE VELIGER Vol. 12; No. 1 Dorsal sculpture of upraised transverse ridges covering entire mipperishellsuntace er ete eee eter avena Dorsal surface only partially sculptured with transverse ridges emanating from both terminals .......... catalinensis Transverse ridges emanate restrictedly from each termin- al; yellow terminals on white shells, orange terminals on colored shells; columellar carina weakly, finely formed ie ceine tact Meee et eh Ae aequalis aequalis Transverse ridges emanating from each terminal; yellow to orange terminal tips; pronounced, upraised, white carina on forward half of columella ..... aequalis vidleri Transverse ridges emanating away from each terminal, and yellow terminal tips; shell broader, with a wider curving carina on the forward half of the columella oH ten Uren eee eae ieee bellamaris LOCALITY INDEX Many of the localities listed here were obtained from handwritten labels in various collections. Every effort has been made to verify the spellings, but in some instances certain place-names were not found on any map or atlas available to me; it is regretted if any discrepancies occur. 1. Aguachale, NE Baja California del Norte; approx. 24 miles S of San Felipe 2. ibid.; in 5 feet of water 3. ibid.; 2 miles S of — 4. Albemarle Island (= Isabella Island), Galapagos Islands, Ecuador 5. Avalon, Catalina Island, S. California; in 40 fathoms 6. Bahia de Adair, Sonora, West Mexico; approx. 20 miles N of Punta Penasco 7. Baja Isla Grande (= Tiburon Island), Gulf of Cali- fornia 8. Bird Island, Catalina Island, S. California; in 35 to 40 feet of water 9. Calito de Campos, Michoacan, Mexico; N of Aca- pulco 10. Calito Mero, Peru 11. Carpinteria, California; deep water 12. Catalina Island, California; approx. 22 miles W of San Pedro 13. ibid.; at the Isthmus in 35 feet of water 14. Cerralvo Island, SE Baja California; just E of La Paz 15. Concepcion Bay, E Baja California del Sur; just S of Mulege 16. Corona del Mar, California ; just S of Newport Beach 17. Creston Island, Mazatlan, Sinaloa, Mexico; in 25 feet of water, on gorgonians 18. Deer Island, Guaymas, Sonora, Mexico; in deep water . Dominica, West Indies; Monte Christi Beach . Estero Soldado, Guaymas, Sonora, Mexico . Galapagos Islands, Ecuador . Guaymas, Sonora, Mexico . Key Largo, Florida Keys, Florida . La Abreojos, W Baja California del Sur, approx. 26°40’ N Lat.; 113°35’ W Long. . Laguna Beach, Orange County, California; in 40 to 50 feet of water . Las Gaviotas, Mazatlan, Sinaloa, Mexico . Magdalena Bay, SW Baja California del Sur . Manzanillo, Colima, Mexico . ibid.; El Dorado Bay . Mazatlan, Sinaloa, Mexico . Mission Bay, San Diego, California . Monterey Bay, Monterey, California . Morro Bay, Pismo Beach, California; in 80 feet of water . Newport Beach, California . ibid; off breakwater in 20 - 25 feet of water . Ocean Park, California, adjacent to Venice: 5 miles W in 300 feet of water (J. L. Baxter) . Pajaros, Mazatlan, Sinaloa, Mexico . Panama Bay, Pacific Panama, W Central America . Panama City, Panama; in deep water . Perlas Islands, Panama Bay . Playa del Rey, California; in 180 feet of water . Punta Diggs (Punta Estrella), E Baja California del Norte; approx. 6 miles S of San Felipe . Point Fermin, San Pedro, California . Puertecitos, E Baja California del Norte; approx. 75 miles S of San Felipe _ Puerto Escondido, E Baja Califomia del Sur; 11 miles S of Loreto . Pulmo Reef, SE Baja California del Sur; approx. 70 miles S of La Paz . Punta Cameron, Mazatlan, Sinaloa, Mexico . Punta Penasco (Cholla Bay), Sonora, Mexico . Punta San Ignacio, Punta Penasco, Sonora, Mexico . Redondo Beach, California; in 100 feet of water (R. Mistrell) . Santa Barbara, California . Santa Cruz, Nayarit, Mexico; 15 miles S of San Blas . San Carlos Bay, Guaymas, Sonora, Mexico; dredged in 17 fathoms . San Diego Bay, San Diego, California; entrance . San Felipe, E. Baja California del Norte . San Francisco Bay, Guaymas, Sonora, Mexico . ibid.; dredged from 16 fathoms . San Onofre, California; approx. 18 miles N of Ocean- side (C. C. Finlay) . San Pedro, California (Mrs. L. C. Oldroyd) THE VELIGER, Vol. 12, No. 1 [C. N.CateE] Plate 7 Figure 1 Figure 2 Simnia rufa (SowERBy 24, 1832) Simnia rufa var. inflexa (SowERBy 24, 1832) Pulmo Reef xs 3 Estero Soldado x34 Figure 3 Figure 4 Simnia aequalis aequalis (SowERBy 2"4, 1832) Simnia aequalis vidleri (SowERBY 34, 1881) Point Diggs xX 2% Morro Bay 25 Figure 5 Figure 6 Simnia avena (Sowersy 24, 1832) Simnia bellamaris (BERRY, 1946) Creston Island xX 5 San Diego Bay X 3 photographs by R. PoorMaN Vol. 12; No. I THE VELIGER Page 97 @ CAMBRIA PMORRO BAY “\@ PISMO BEACH 7" S DO) 360 ZS > he GOLETA ; XSceaSANTA BARBARA PLAYA DEL REY): REDONDO BEACH: > g.SAN PEDRO 333 SANTA » : es / BARBARA |. 3 Vee LOS ANGELES ~~ Tee SAN (=) atin _ 1. ~—N _— (ED Ss = iv 4 CORONADGS “a 60. ibid.; off breakwater 61. Santa Monica, California; 44 miles W of (J. L. Baxter) 62. Santa Rosalia, E Baja California del Sur 63. Saladita Bay, Guaymas, Sonora, Mexico 64. Tabago Island, Honda Bay in Panama Bay; 12 miles SW of Panama 65. Venado Beach, Panama, Central America 66. Venado Island, Panama, Central America Jenneria pustulata (LicutFoot, 1786) Cat. Portland Mus., London 1786 (2230) : 106 — (not of SoLaNnpER, 1786; nor Lamarck, 1810) (Plate 8, Figure 9) Type Locality here designated: Cholla Bay, Punta Pefiasco, Sonora, Mexico (30°40’ N Lat., 113°20’ W Long.) (emend. China: Lister error; LicHTFoot, 1786) This is a fairly common species in some localities; it ranges from the upper Gulf of California south to Ecuador (KEEN, 1958). It has been demonstrated that the species is most closely related to the Ovulidae (see D’Asaro, 1969), and it is therefore included in this report. The shell shape of Jenneria pustulata is that of a cypraeid; the apertural teeth traverse both base and outer lip as sharply elevated white ridges; the pale grey dorsum is divided by a mantle line, and the overall dorsal surface is thickly overlaid with bright orange pustules, which are encircled by a brown ring — there are two large brown spots superimposed over the area inward from each ter- minal. The shells average about 20 by 12.5 by 8.2 mm in length, width, and height, respectively. Those specimens that I have seen live in the sand, digging into it with the the receding tide, at Cholla Bay. Localities: 2 3 22 26 29 38 44 45 52 65 Simnia rufa (SowERBY", 1832) Conch. Illust., London: fig. 58 (Plate 7, Figures 1, 2; Plate 9, Figures 13, 14) Syn.: Ovulum inflecum SowErBy", 1832 Conch. Illust., London, fig. 60 Ovula californica Reeve, 1865 (Sowersy MS) Conch. Icon., 15 Ovulum, fig. 50 Ovula neglecta Reeve, 1865 Conch. Icon., 15 Ovulum, fig. 62 This is a fairly common, distinctive species. It differs from other members of the genus by having a generally narrower shell; by being rectangularly elongate; by having Page 98 THE VELIGER Vol. 12; No. 1 if = ara y \ eae AAG ’ 1) allt “BAH i CORON AOS eA oe SS 5 ARIZ. ' NEW MEX, ' : ENSENADA ©... 0 Q PUNTA BANDA yJ*: ER ON ' ' SANTO TOMAS RE RTOIBERASC i wih ppcocccosccomacaseoced! ' TINS oes ‘ —eo,. TEXAS PLAYA , f° SANTA MARIA — LA LIBERTAD pete DE LA GUARDA H ScuapaLuee AHIA)DE LOS ANGELES |i \. GONZAGA Hay 2 “ ;TIBURON |. XS, BAHIA KINO ceoROs}} - .SAN PEDRO ek & aE MPALME SEBASTIAN ms GUAYMAS , MEXICO VIZCAINO BAHIA DE TOPOLOBAMPO pESPIRITU SANTOS (CERRALVO \ TROPIC OF cancer & MAZATLAN XPAL MITO OEL VERDE PUERTO CHILENO | |. SAN JUANITO, TREs, & 1, MARIA MADRE 1. MARIA MAGDALENA ARIAS | CABO SAN LUCAS *ranco EL TULE 1. MARIA CLEOFAS BAHIA TENACATITA e BARRA DE NAVIDAD Ns MANZANILLO REVILLAGIGEDO® CALETA PACIFIC gino ACAPULCO is : OCEAN } Honea tes. ns 2 1 if | ; © CLIPPERTON 0 100 200 300 1 | 1. | eneenssoseeese amen MILES i 114° 108° 102° THE VELIGER, Vol. 12, No. 1 Figure 7 Simnia loebbeckeana (WEINKAUFF, 1881) Magdalena Bay Xx 2 Jenneria pustulata (Licutroort, 1786) Puertecitos X 2% Figure 11 Cyphoma intermedia (SowERBy ***t, 1828) Dominica x 12 photographs by R. PoorMAN [C. N.CateE] Plate 8 Figure 8 Simnia catalinensis (BERRY, 1916) Avalon DS Ore Figure 10 Cyphoma emarginata (Sowerby ', 1830) Puertecitos Figure 12 Cyphoma gibbosa (LINNAEUS, 1758) Key Largo xX 2 Vol. 12; No. 1 THE VELIGER Page 99 MEXICO Zé x / SRS | ; L j HON'DURAS | Qe Vi ! ents Ee hep CARIBBEAN SEA PACWIRUG GOLFO DE NICOYA PANAMA 6° Ss DE PANAMA 9? FETS ° ISLA DE coco CULPEPPER I. WENMAN Le GALAPAGOS ABINGDON |. 9 ISLANDS QBINOLOE |. ca TOWER. : IN Geis COLOMBIA NARBOROUGHLD ' ip 1, 4, SO. SEYMOUR |. Bsc ALBEMARLE 1G 3 ° INDEFATIGABLE 1. meee, Se BARRINGTON |” SS CHATHAM I. if \ | ° PE GWA DOI at | CHARLES aa alae 6 SO ee iH eee CABO SAN LORENZO<: » MANTA Page 100 a smooth dorsum without any important sculpturing (sometimes exceedingly faint growth lines are visible at the terminals) ; but most importantly it differs by having an upraised carinal ridge the full length of the columella. The shell may be either white or of varying shades from purple-brown to a striking deep purple; the shell mar- gins may have an orange cast at times. The shell varies in length up to about 24mm; the animal lives on gorgonians and sea-fans, and will likely acquire the color of the host colony on which it lives. The species occurs abundantly at Guaymas and the off shore islands and reefs of southeastern Baja California. Localities: 6 7 14 15 18 20 22 24 28 30 37 38 44 46 49 53 59 62 63 64 Simnia avena (SOwERBY", 1832) Conch. Illust., London, fig. 59 (Plate 7, Figure 5) Syn.: Ovula livida ReEve, 1865 Conch. Icon., 15 Ovulum, fig. 63 This species seems to be uncommon. It is easy to identify because of the general appearance of the shell; it is a small form, rarely measuring more than 14 mm in length. It differs from other Simnia species by being broad for its length; and, most importantly, the shell is ribbed over the dorsum, transversely from one terminal to the other. These sharply upraised ridges are the most convenient means of identification. As it is presently known, the species seems to be restric- ted to the west coast of Mexico and Central America to Panama, although specimens have been reported from Calita Mero, Peru; also the species is well established at the Galapagos Islands. Localities: 10 17 20 21 30 37 38 56 . Simnia aequalis aequalis (SOWERBY ", 1832) Conch. Illust., London, fig. 61 (Plate 7, Figure 3; Plate 9, Figures 15, 17) Syn.: Ovula variabilis REEvE, 1865 (C. B. ApAMs MS) Conch. Icon., 15 Ovulum, fig. 60 Neosimnia quaylei Lowe, 1935 Trans. San Diego Soc. Nat. Hist. 8 (6): 74 Din By IHR, Neosimnia vidlert tyrianthina Berry, 1960 Leafl. Malac. 1 (19): 118 (31 Dec.) This is possibly the most common Simnia species occurring in the Panamic region, with the center of abundance along the shores of northeast Baja California, and appearing to occur to a limited extent in the northern half of the THE VELIGER Vol. 12; No. 1 Gulf of California. Although the species seems to have many synonyms, it appears to possess a distinctive color and form (this appears to be the only simniid in which color can be used as a criterion for identification). The shell varies in length up to about 19mm; the animal lives on variously colored gorgonians. This species differs from its congeners by having yellow terminal tips on white shells, the color blending into dull orange on shells of rose and lavender-brown; it dif- fers further by having transverse ribbing on the dorsal surface radiating away from the terminal openings; and, unlike its subspecies, it has a very weakly formed carinal ridge on the forward half of the columella. This combi- nation of shell characters is missing from all other eastern Pacific Simnia, but is present in all of the mentioned synonymic species. Localities: 2 3 6 20 22 42 44 45 53 55 57 Simnia aequalis vidleri (SowERBY™, 1881) Proc. Malacol. Soc. London 1881: 683; plt. 56, fig. 1 (Plate 7, Figure 4; Plate 9, Figure 16) Syn.: Ovula subrostrata (SowERByY", 1832) Proc. Zool. Soc. London 1848: 136 This subspecies is fairly common below the low tide mark, and is found living on gorgonians and related organisms. The subspecies is geographically separated from the nom- inate species, which lives in the northern reaches of the Gulf of California. Although having the color and morphological characters of the species in the strict sense, it is separated by possessing a heavily-formed, white, sharply upraised carinal ridge that traverses the forward half of the columella. It is this feature, along with its West American locality, that separates it from all other Simnia forms. These shells also seem to grow longer and broader, varying in length up to 25 mm. Szmnia aequalis vidleri appears not to occur in the Gulf of California, but to be limited to American coastal waters, including the offshore islands, from Monterey Bay, California, to the west coast of Central America, Panama, and the Galapagos Islands. Localities: 4 21 22 24 30 32 33 35 37 38 40 50 Simnia bellamaris (Berry, 1946) Journ. Conch., Manchester 22 (8): 190; fig. 1 (Plate 7, Figure 6; Plate 10, Figure 21) This species is rare and seems presently to be restricted to the bays adjacent to San Diego, California. It is broader THE VELIGcER, Vol. 12, No. 1 [C. N.Cate] Plate 9 oa pecho a, Sour i Californienm_ Wo. o [ - Af Cexa, Sow - Figure 13 ay a Simnia rufa (SowErRBy 2"4, 1832) Simnia rufa (SowErBy 24, 1832) Syntypes X 2 inflexa syntypes x 2 Sam AAW ot 15a Simnia aequalis aequalis (SowERBY 24, 1832) Figure 16 15b Simnia avena (Sowersy 74, 1832) Simnia aequalis vidleri (SowERBy 3°, 1881) BM(NH): No. 81.5.20.31 | Monterey X 2 cnhractratinm.. Samnerk igure 18a Simnia aequalis aequalis (SowERBY 2™4, 1832) Simnia aequalis aequalis (SowERBy 7", 1832) 18b,c,d Simnia avena (Sowersy 2"4, 1832) (rufa-subrostratum) photographs by A. Myra KEENn iy THE VELIGER, Vol. 12, No. 1 [C. N.CarE] Plate 10 ie ee NS AS SN tee Gee Ge ee Figure 19 Figure 20 Simnia aequalis aequalis (SowERBy 2"4, 1832) Simnia aequalis aequalis (SowERBy 2°4, 1832) (tyrianthina Berry ) Holotype 16mm (quaylei LowE) Type SDNHM No. 602 xX 3 No...7846..270 7 Neojimnia bellé sosimr o cotal iwalon . 4 Figure 22 Simnia catalinensis (BERRY, 1916) Type (24 mm) Figure 21 Simnia bellamaris (BERRY, 1946) a - Holotype (26 mm) b - Paratype (22 mm) photographs by James H. McLEAN = no rs i Y 7 p a 7 Shece : - ve a ro es nf at a os mn semb if . - ce man io rN et) eo : ; = ~ ; Vol. 12; No. 1 with a wider aperture than the other eastern Pacific Simnia, being particularly wide for the length of the shell; the average measurements of shells examined were 18 mm long and 13 mm wide. The species possesses many of the morphological features of S. aequalis vidleri (see above), but seems to differ from it mostly in the dimensions of the shell and by a more heavily formed columellar carina. Otherwise it very closely approaches S. aequalis vidlert. Since S. bellamaris might well be a localized morph- form of this species, it is listed here provisionally. Localities: 31 54 Simnia loebbeckeana (WEINKAUFF, 1881) Syst. Conch. Cab., Mart. Chemn. ed., 5/3: 197; plt. 50, figs. 6, 7 (Plate 8, Figure 7) Syn.: Ovulum fornicarium Keep, 1887 (not of SowER- By ', 1828) ; West Coast Shells 1887: 61; fig. 47 Ovula barbarensis Dati, 1892 Proc. U.S. Nat. Mus., 15: 206; plt. 21, fig. 1 This is a fairly common species, ranging along the West American coast from Magdalena Bay, Baja California, north to Monterey Bay, California. The shell is almost always ivory colored, although some specimens examined showed a faint pink blush of color. The average shell size is about 19 mm, but an occasional specimen may meas- ure 24 mm in length (Calif. Acad. Sci. Coll.). The species is distinct, with a morphology that seems distantly related to a species occurring in deep water off Catalina Island, Simnia catalinensis (Berry, 1916). It differs from this species, however, by being generally smal- ler and narrower; and, most importantly, by having no dorsal sculpturing, the shell being smooth and glossy throughout. Localities: 11 16 27 32 36 41 43 51 58 59 61 Simnia catalinensis (BERRY, 1916) Nautilus 30 (2): 21; plt. 5, fig. 3 (Plate 8, Figure 8; Plate 10, Figure 22) This deep water species is not common, and presently seems to be restricted to the offshore environs of Catalina Island, California. The shells are large, lightweight in construction and bulbously broad. Average shell length is 25 mm and the breadth is 14.5 mm; the shell color is pale ivory-white; it differs most importantly from Simnia loeb- beckeana by having transverse rib sculpturing on the dor- sum at either end-quarter of the shell; it is also a larger THE VELIGER Page 101 simniid species. Simnia loebbeckeana, the previously dis- cussed species, has a smooth dorsal surface without trans- verse ribbing. Localities: 5 8 12 13 Cyphoma emarginata (SowerBy', 1830) Spec. Conch. 1: Ovulum 1: 7; plt. 54, figs. 54, 55 (Plate 8, Figure 10) Syn.: Cyphoma marginata CHENU, 1859 (used in error) Man. de Conchyl. 1: 273; figs. 1789, 1793 This is a relatively common species in certain localities. There may be some relationship between this form and the West Indian Cyphoma gibbosa (Linnaeus, 1758), Plate 8, Figure 12, especially the form called C. intermedia (Sowersy', 1828), Plate 8, Figure 11. This latter species may be only an uncalloused intermediate to the heavily margined form mentioned above. The Panamic shells are off-white to whitish beige, with a pale beige blush at the terminal openings; adapical funicular cord gives the posterior terminal beak a peculiar twist to the right; however, the most important shell char- acter is the transverse dorsal ridge, which identifies the species generically. Cyphoma emarginata seems to be the only species in this genus occurring in the eastern Pacific region. Shells vary up to 28 by 16 by 12.5 mm in length, width, and height, respectively. Localities: 3 9 20 44 47 — Cyphoma intermedia: 19 Cyphoma gibbosa: 23 ACKNOWLEDGMENTS In the preparation of this paper I enjoyed the help and assistance of many people and I wish to thank Dr. Myra Keen, Stanford University; Dr. Leo Hertlein, California Academy of Sciences; Dr. James McLean, Los Angeles County Museum of Natural History; Dr. George Radwin, San Diego Museum of Natural History; Dr. Takeo Susuki, University of California at Los Angeles; and Dr. Eugene Coan, Stanford University: for the use of the collec- tions, for their counsel and for help with access to obscure literature. To several private collectors go my thanks for the use of their collections from the Gulf of California; these especially include Twila Bratcher, Roy and Forrest Poorman, Helen DuShane, and Gale Sphon. I wish to extend special thanks to Dr. Myra Keen for the use of photographs taken by her of the simniid types in the British Museum (Natural History) (Plate 9, Fig- ures 13 to 19) ; to Dr. James McLean for additional type Page 102 THE VELIGER photographs from his institution (Plate 10, Figures 19 to 22); to Roy Poorman for photographing the specimens illustrated in Plate 7 and 8 (Figures 1 to 12) ; to Dr. Takeo Susuki for the special processing of the photographs; and to Mrs. Emily Reid for the excellently drawn maps. To Jean Cate goes a very special thanks for her interest in my work, and the assistance she has given in many ways, all of which make for the success of this paper. LITERATURE CITED D’Asaro, Cuarzes N. 1969. The egg capsules of Jenneria pustulata (LicHTFOOT, 1786), with notes on spawning in the laboratory. The Veliger 11 (3) : 182 - 184; 1 text fig.; 1 table (1 January 1969) TREDALE, Tom 1935. Australian cowries, pt. I. Austral. Zool., 8 (2): 96 to 135; plts. 8-9 KEEN, A. MyRA - 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford, Calif. (Stanford Univ. Press) LicHTFooT, JoHN 1786. A catalogue of the Portland Museum, lately the property of the Duchess Dowager of Portland, deceased ... . London. pp. i- viii+ 1-194 ScHILper, FRANz ALFRED 1968. The generic classification of cowries. The Veliger 10 (3) : 264-273 (1 January 1968) Sowersy, GEorGE BRETTINGHAM (2%? of name) 1832. Conchological illustrations. Figures 1 - 61 Vol. 12; No. 1 — Vol. 12; No. 1 THE VELIGER Page 103 The Eastern Pacific Cowries CRAWFORD N. CATE 12719 San Vicente Boulevard, Los Angeles, California 90049 (Plates 11 to 15; 3 Maps) INTRODUCTION THE PURPOSE OF THIS PAPER is to provide a checklist of the cowrie species known from the Eastern Pacific Region of the Americas, including such islands and island groups as the Galapagos, Clipperton, Cocos, Revillagigedos and Guadalupe. All of these offshore localities share a similar molluscan fauna. It seems pertinent, therefore, to mention a few facts regarding these islands. First in geographical importance are the Galapagos Is- lands, which provide a home for many cowrie species in- cluding both eastern and western forms. The archipelago consists of 10 major islands, the largest of which is Isa- bella (Albemarle). Other more important islands, with their earlier names are: Santa Cruz (Indefatigable), San Cristobal (Chatham), San Salvador (James), Fernan- dina (Narborough), Santa Maria (Charles), and Es- pafiola (Hood). The collecting localities at these islands are, for the most part, horizontal strata, lava outcroppings, boulder strewn extensions of black basaltic lava with at- tached algae, and a minimum of sandy beaches. Clipperton Island appears to be the crossroads for the eastern and western cowries, as here the two faunas come together. This former atoll is located on the western peri- meter of the Eastern Pacific cowrie region and seems to provide a bridge that has enabled some of the more western species to migrate to the American mainland. Clipperton Island is roughly 2 square miles of irregular atoll land area; it is uninhabited and is about 670 miles southwest of Mexico. With a diameter of about 24 miles, it encloses a rocky projection of about 85 feet in height, the highest point on the atoll. The shore area appears to be ideal for cypraeids with its sandy beaches, some of which are strewn with rock and coral rubble, and the adjacent coral and algae reef-flats. Luria isabellamexicana (STEARNS, 1893) seems to be the native cowrie species, considering the east and west extremes of its range. It appears to reproduce in greatest abundance at Clipperton Island, whence its range extends eastward to the west Mexican-Central American inter- tidal waters. Westward the species emerges again in Ha- waiian subtidal waters as L. isabella controversa (Gray, 1824). This range determination becomes more valid when one considers that L. isabella atriceps SCHILDER & ScHILper, 1938, a clearly distinguishable subspecies, can be observed to commence its West-Central Pacific range in the Hawaiian Islands, a fact that should not have been ignored in Cate (1965). A study of a series of these sub- species shows little or no intergrading between them, even though they share overlapping habitats. Cocos Island, Costa Rica, is an uninhabited island of approximately 18 square miles, situated southwesterly from the mainland. Not much field work has been under- taken at this presently inaccessible locality, and, therefore there is not much known of its cowrie fauna. The Revillagigedos Islands lie about 420 miles west of the Mexican mainland and, nearly 240 miles south of Cape San Lucas, Baja California del Sur. These islands belong to Mexico, and consist mainly of Clarion and So- corro Islands; Roca Partida Island is the westernmost of this group (see HERTLEIN &« Hanna, 1930). Some field work has been accomplished at these islands, resulting in a somewhat better knowledge of the cowries there. How- ever, isolation and inaccessibility still limit the field work in this area. The Tres Marias Islands, Mexico, on the other hand, are only about 50 miles off the mainland coast of the State of Nayarit, and some 200 miles southeast of Cape San Lucas (Strone « Hanna, 1930). Several collecting expeditions to these islands have fairly well explored the fauna, so that we have an adequately complete knowledge of the cowrie species occurring in these islands. The Pacific coast of Central America represents the connecting link, or land bridge, between North and South America; it extends officially from the southern boundary of Mexico to the northwest boundary of Colombia. This coastline includes numerous bays, islets, clif-bound shores, and rocky projections into the sea; coral tables at the Page 104 ocean surface, coral reefs, and extensive sandy beaches. Mangroves line areas of quiet backwaters; to all of this is added a tropical water temperature. There are at least 5 of the Eastern Pacific cowrie species living within this warm-water range. The northern coast of Pacific South America provides for at least 2 more, with the remainder confined to the Gulf of California-West America, and the listed islands. The Gulf of California, an arm of the Pacific Ocean, extends northwest into the mainland of North America. It is bounded on the East by mainland Mexico, and on the West by the peninsula of Baja California. It is interesting to note that most of the cowrie species in this province thrive within the confines of the Gulf as well as along the open shoreline. The one exception is Zonaria annettae annettae (Dati, 1909), which appears to be completely restricted to the waters of the Gulf. The west coast of North America from Monterey, Cali- fornia in the North to the proximity of Cedros Island, West Baja California, in the South, provides another de- limited range for cowries. Perhaps the most notable fac- tor in the living conditions in this area are the cold water upweilings, a condition not generally found in the other areas included in this discussion. Zonaria (Neobernaya) spadicea (Swainson, 1823) may be collected at nearly any point in this range that provides suitable ecological conditions for cowries; this includes all of the islands such as the southern Guadalupe Island. Guadalupe Island, a Mexican island possession, is situ- ated about 275 miles west of El Rosario, Baja California del Norte, and about 185 miles southwest of San Diego, California. The island is surrounded by very deep water, up to 2000 fathoms; it is of volcanic origin. It is said to possess much the same marine ecological conditions as those observed on the California coast and Californian islands (Stronc & Hanna, 1930; CHace, 1958). No provision is made here to include a report on the possibility of cypraeids occurring at the remote, southern Chilean islands of San Felix (20°20’S Lat.; 80°10’W Long.) ; San Ambrosio (26°40’S Lat;80°00’W Long.) ; and Juan Fernandez (33°30’S Lat.; 79°00’W Long.). Special interest attaches to the discovery of two cowrie species from the western Pacific on the beaches of Baja California del Sur by Mrs. Helen DuShane, Whittier, Cali- fornia. On July 6, 1956 she found a dead, decorticated specimen, though with some color and fresh markings, of Erronea caurica (LinNAEUS, 1758) (Plate 14, Figure 23) at Rancho Eureka, Punta Arena. The morphological details of this specimen are: (42.6 23.0 18.5 18 16). On July 7 Mrs. DuShane found a specimen of Staphy- laea staphylaea (LinnaEus, 1758) (Plate 14, Figure 24) at Los Chilenos, a locality 4 miles beyond Rancho El THE VELIGER Vol. 12; No. 1 Tule, but before reaching Cabo San Lucas. The shell was in excellent coridition, imbedded in a clump of fresh sea weed deposited on the beach. The details of this shell are: (20.0 12.0 10.0 24 20). The largest and smallest shells available to me for this study are listed to provide an estimate of size variation found in the species. The 5 figures given are, in the fol- lowing order: length, width, height (all in millimeters), number of teeth on outer lip, number of teeth on columel- lar lip. ACKNOWLEDGMENTS There are many people to whom I wish to express my sincere thanks, in addition to those mentioned elsewhere in this paper, for their contributions of material, field infor- mation, and literature references; they are: the late Con- rad Limbaugh, Emery Chace, Mrs. Helen DuShane, Mr. and Mrs. Ben Purdy, Mrs. Twila Bratcher, Glen Bickford, John Fitch, Lawrence Thomas, Gale Sphon, Mr. and Mrs. Michael O’Brien, Mrs. Emily Reid (for the maps), Dr. Takeo Susuki (for special processing of the photographs) and, finally, Jean Cate for helpful suggestions and con- tinued encouragement of my work as well as for the photography for the plate illustrations. LOCALITY INDEX Many of the localities listed here were obtained from handwritten labels in various collections. Every effort has been made to verify the spellings, but in some instances certain place-names were not found on any map or atlas available to me; it is regretted #f any discrepancies occur. 1. Acapulco, Guerrero, Mexico 2. Agua Chale (approx. 24 mi S of San Felipe), E Baja California del Norte, Mexico 3. ibid. (subfossil, Indian kitchen midden) 4. Albemarle Island, Galapagos Islands, Ecuador 5. ibid. (Banks Bay) ; 6. ibid., (Tagus Cove) (HERTLEIN, 1939; Pleistocene) 7. Algodones (Bahia), Sonora, Mexico (Tesora Exped.) March 1966 : 8. Almejas (Playa), W Baja California del Norte, Mex- ico (adjacent to Magdalena Bay) 9. Angel de la Guarda Island, Gulf of California 10. Anacapa Island, off Santa Barbara, California 11. Audencia (Bahia de), Colima, Mexico; Churea Ex- pedition January 1962 12. Bahia Honda, Panama Vol. 12; No. 1 THE VELIGER Page 105 13. Bahia Salahua, 3 mi. N of Manzanillo, Colima, Mexico (Las Hondas Hotel area) 14. Bahia Tenacatita (60 mi. N of Manzanillo, Colima) 15. Balboa Bay, Orange County, California 16. Balboa, Canal Zone, Panama 17. see no. 5, above 18. Barra de Navidad (30 mi N of Manzanillo), Jalis- co, Mexico 19. ibid., first Churea Expedition, 7-11 January 1962 20. ibid., second Churea Expedition, February 1963 21. Bat Island, Costa Rica 22. Bacochibampo Bay, 1 mi N of Guaymas, Sonora 23. Bomber Beach, Puertecitos, E Baja California del Norte, Mexico 24. Buena Vista, Las Palmas Bay (23°35’N Lat.; 109° 40’ W Long.), East Baja California del Sur 25. Cabo San Lorenzo, Ecuador 25a. Cabo San Lucas, Baja California del Sur 26. Cabrillo Beach, San Pedro, California 27. Caleta de Campo, Guerrero, Mexico; just N of Acapulco 28. Cambria, California (subtidal rocks) 29. Cambria Radar Station, California (14 mi. offshore, 67 - 70 feet of water) 30. Cape San Lucas, S tip of Baja California del Sur 31. Caracol (Playa) near Bahia San Carlos, Sonora, Mexico; Tesora Expedition, 29 March 1966 32. Cardalitos, Peru 33. Carmen Island, Marques Bay (offshore from Lore- to), Baja California del Sur 34. Carmen Island, Salinas Bay, Baja California del Sur 35. Catalina Island, California 36. Cerralvo Island, Gulf of La Paz, E Baja Califor- nia del Sur 37. Changame Island, Panama Bay, Panama 38. Charles Island, Galapagos Islands 39. Chatham Island, Galapagos Islands 40. Chatham Bay, Cocos Island, Costa Rica 41. Cholla Bay, Puerto Pefiasco, Sonora, Mexico 42. Clarion Island (Revillagigedos Islands), Mexico 43. Cleofas Island, Tres Marias Islands, Mexico 44. ibid., (Yellow Bluff) 45. Coaloil Point, Goleta, California (20 feet of water) 46. Clipperton Island (11°00’N; 109°20’W); 1958 47. ibid., (HERTLEIN, 1937) 48. Cocos Island (5°32’N; 86°59’W), Costa Rica 49. ibid., (INGRAM, 1951) 50. ibid., Chatham Bay 51. Concepcion Bay, East Baja California del Sur 52. Corinto, Nicaragua 53. Corona del Mar, Orange County, California 54. Coronado Island, W Baja California del Norte 55. Coyote Lagoon (Bahia), Concepcion Bay, E Baja California del Sur 56. Creston Island, Mazatlan, Sinaloa; 22 Dec. 1960 57. ibid., under rocks, 25 feet of water, January 1964 58. Dana Point, Orange County, California 59. Desemboque (Playa), Sonora, Mexico 60. Enchura Bay, Peru 61. El Coyote Bay, within Concepcion Bay, E Baja Cali- fornia del Sur 62. El Tule (Rancho), approx. 9 mi E of Cabo San Lucas, Baja California del Sur, 22 February 1963 63. Elwood Beach, Santa Barbara County, California 63a. Empalme (approx. 10 mi. S of Guaymas), Sonora 64. Ensenada, W Baja California del Norte 65. Espiritu Santo Island, E Baja California del Sur 66. Flamenco Island, Panama Bay, Panama (under rocks at minus tide; December 1960) 67. Galapagos Islands (00°01’S; 90°30’ W) ; Ecuador 68. ibid., HerTLEIN, 1939 (Pleistocene) 69. Gaviota Point, Mazatlan, Sinaloa; second Churea Expedition, 22 January 1963 70. Geronimo Island, off Punta Baja, W Baja California del Norte 71. Goleta, Santa Barbara County, California 72. ibid., Coaloil Point, on rocks, minus tide 73. ibid., Cookout Beach, University of California at Santa Barbara 74. ibid., reef off Devereau School, N Goleta 74a. Guadalupe Island, Mexico (29°00’N; 120°00’ W) 75. Guanacaste, Costa Rica 76. Guaymas, Sonora, Mexico 76a. Gulf of Fonseca, Costa Rica-Nicaragua 77. Gulf of Nicoya, Costa Rica 78. Gulf of Montijo, Panama 79. Hood Island, Galapagos Islands 80. Indefatigable Island, Galapagos Islands 81. ibid., Academy Bay 82. Isabel Island, Galapagos Islands 82a. Isla Angel de la Guarda, Gulf of California 83. Isla de Malpelo, Colombia 84. Isla San Benito (Bahia de Sebastian Vizcaino), W Baja California del Norte 85. Isla San Luis, E Baja California del Norte 86. Isla Santa Cruz, Galapagos Islands 87. James Island, Galapagos Islands 88. ibid., Sulivan Bay 88a. ibid., HERTLEIN, 1939 (Pleistocene) 89. Kino Bay, Sonora (approx. 75 mi. N of Guaymas) 90. Kobbee Beach, Canal Zone, Pacific Panama 91. La Jolla, San Diego County, California 93. La Libertad, San Salvador 94. La Paz, SE Baja California del Sur Page 106 THE VELIGER CARIBBEAN ee ee 3c ae “J GUATEMALA 7 AE HO/INDURAS PACTFIC GOL FO¥ DE NICOYA CULPEPPER |. WENMAN Le NARBOROUGH LJ I. ALBEMARLE I.C.; GALAPAGOS ABINGDON |. 9 ISLANDS BINDLOE |. TOWER, caines $0. SEYMOUR I. 9° ES INDEFATIGABLE I. = ! BARRINGTON |” SS CHATHAM I. CHARLES” = F HOOD |. CABO SAN LORENZO MECUADOR Vol. 12; No. 1 PANAMA COLOMBIA ~ Vol. 12; No. 1 THE VELIGER Page 107 95. La Penita, Nayarit (between Compostella and Puer- 140. ibid., Palos Verdes Point to Vallarta) 141, Panama, Pacific Central America 96. Las Animas (Bahia) mainland, W of Isla Angel de 142. ibid., Panama Bay la Guarda, E Baja California del Norte 143. ibid., Panama Canal (cement wall within Pacific 97. Las Gaviotas Beach, Mazatlan, Sinaloa entrance) 98. Las Varas, Nayarit (out of Tepic, via Compostella ) 144. Pelican Point, Puerto Pefasco, Sonora 99. Lobitos, Peru 145. Perlas Island, Panama Bay, Pacific Panama 100. Loreto, E Baja California del Sur 146. Playa Almejas (adjacent Magdalena Bay), W Baja 101. ibid., (very small shells) . California 102. Los Angeles Bay (shore W of Isla Angel de la Guar- 147. see no. 31 da) E Baja California del Norte 148. see no. 59 103. Los Chilenos (8 mi. E of Cabo San Lucas), Baja Ca- 149. Playa Santa Maria (Cabo San Quintin), W Baja lifornia del Sur California 104. Magdalena Bay, W Baja California del Sur 150. see no. 130 105. Manta, Ecuador 151. Point Conception, California 106. Manacora, Peru 152. Point Fermin, San Pedro, California 107. Manzanello (Boca Chamela) = Manzanillo, Colima 153. Point Loma, San Diego, Calif. (lower lighthouse) 108. Manzanillo, Colima 154. Point San Telmo (mainland landfall W of Isla Santa 109. ibid., Boca Chamela Cruz), E Baja California del Sur 110. ibid., 20 miles W of - 155. Point Vicente, Palos Verdes Peninsula, California 111. ibid., 100 miles S of - 156. Portuguese Bend, Palos Verdes Peninsula, California 112. Margarita Bay, La Paz, E Baja California del Sur 157. Puertecitos (approx. 180 mi S of California-Mexico 113. Maria Madre Island, Tres Marias Islands, Nayarit border), E Baja California del Norte 114. ibid., EmMerson & Op, 1963 (dredge, off Arroyo 158. ibid., 24 mi N of - Honcho) 159. ibid., 28 mi S of - 115. ibid., Puerto Balleto 160. see no. 115 116. Maria Magdalena Island, Tres Marias Islands 161. Puerto Chileno (8 mi E of Cabo San Lucas), Baja 117. Mazatlan, Sinaloa, Mexico California del Sur 118. ibid., Yacht Club 162. Puerto Escondido (approx. 11 mi S of Loreto), E 119. ibid., 100 miles S of - Baja California del Sur 120. ibid., Venado Island 163. ibid., under rocks in the lagoon 121. Melique, Jalisco, Mexico 164. Puerto Grande, San Salvador Island, Galapagos Is- 122. Mendia, Sinaloa, Mexico lands 123. Miramar Beach, Guaymas, Sonora 164a. Puerto Libertad (approx. 60 mi N of Guaymas), 124, Mission Bay, San Diego County, California Sonora, Mexico W235), 126. 2% 128. 129. 130. ISG 132. 133. 134. USI), Modesto, Sinaloa Monserrate Island, E Baja California del Sur (ap- prox. 50 mi. S of Loreto) Monterey Bay, California Montijo, Gulf of Montijo, Pacific Panama Morro Bay, California ibid., Point Buchon Narborough Island, Galapagos Islands Negritos (Parinas), Peru Newport Bay, Orange County, California Newport Beach, Orange County, California Norse Beach (Cholla Bay), Punto Penasco, Sonora 135a. Paita, Peru 136. Sie 138. 139. Paitilla Point, Panama Palmito del Verde (approx. 50 mi. S of Mazatlan) Palo Seco Beach, Canal Zone, Pacific Panama Palos Verdes Peninsula, California 165. 166. 167. 168. 169. 170. yale Wie 7B. 174. 178. 176. Puerto Madre, Chiapas, Mexico Puerto Penasco, Sonora, Mexico Puerto Vallarta (17 mi N of -), Jalisco, Mexico ibid., small specimens from deep water Pulmo Reef, (approx. 70 m S of La Paz), E Baja California del Sur Pulperia Reef, Panama Bay, Pacific Panama Pulpito Point (approx. 40 mi S ofLoreto), E Baja California del Sur Punta Arena (approx. 70 mi N of Cabo Pulmo, E Baja California del Sur Punta Baja (approx. 15 mi S of El Rosario), E Baja California del Norte Punta Banda (approx. 15 mi S of Ensenada), W Baja California del Norte ibid., Cape (Todos Santos Bay) Punta Canoas (approx. 55 mi S of El Rosario), W Page 108 TROPIC OF CANCER THE VELIGER Vol. 12; No. a or AHIA D =o ’ ’ CORONADOS 8 ~. , , 008" Wy / FOb0S SanTyS | ARIZ ; NEW MEX, “. ENSENADA ¢- Inte ; 5 PUNTA canon Jaoain ~~ ' ' SANTO TOMAS “y 3 ’ A OP Pee eee cone cece eae cece! BAY SA PUNTA Se aes PEN AA?) Cc ’ Sao FELIPE /O10S I Ssoeseettoeal “@AGUA PLAYA _, CHALE TEXAS SANTA MARIA “4 PUNTA WILLARD &:.. zs. pusATE. : TOS 4 LA LIBERTAD ! a se |. ANGEL DE LA GUARDA 30 § i panins Zt ¥ \ ais GUADA AN LUI : 1 BAHI&,DE LOS ANGELES ADALUPE Hs Ke SA NP Ne J , Sues ~ \ ped \ 1. \ ge ; 1AN ee MEXICO \. PUNTA ABREOJOS ‘\ 4 “LORETO \ BAHIA CONCEPCION Cx SpueRTO ; SS ESCONDIDO BAHIA DE TOPOLOBAMPO 3s *1. SANTA e ZX cruz - A QSAN JOSE a ESPIRITU SANTO pee lh, “RBUENAVISTA ?&PULMO REEF TODOS SANTOS¥. CABO SAN LUCAS SF anon EDULE PUERTO CHILENO | |. SAN JUANITO, 1, MAR(A MADRE _* 1. MARIA sata oPE Ro MARiAs |. MARIA CLEOFAS § PUERTO VALLARTA BAHIA TENACATITA7%. BARRA DE NAVIDAD y MANZANILLO REVILLAGIGEDO® sal CALETA DE CAMPO ACAPULCO (IG IO UG OG AN @ CLIPPERTON ! at = THE VELIGER, Vol. 12, No. 1 [C. N.Cate] Plate 11 Figure 2 Mauritia maculifera SCHILDER, 1932 Clipperton Island x1 . by Figure 3 Figure 4 Mauritia depressa (Gray, 1824) Mauritia scurra retifer (MENKE, 1829) Clipperton Island xX 14 Clipperton Island x 14 Figure 6 Lyncina vitellus polynesiae SCHILDER & SCHILDER, 1939 Clipperton Island Ke Lyncina schilderorum IREDALE, 1939 Clipperton Island DK: Vol. 12; No. 1 x; /!22° MONTEREY,.:. : Co) MILES 50 BAY ean NAGS oe

Tue VELIGER, Vol. 12, No. 1 [C. N.Care] Plate 17 Figure 7 Mauritia depressa (Gray, 1824) Mauritia scurra indica (GMELIN, Orote Point x 4 Agana Bay OX igs STELLA! Ftc oN Figure 8 Mauritia mauritiana (LINNAEUS, 1758) Tumon Bay Figure 10 Figure 11 Cypraca tigris schilderiana CATE, 1961 Lyncina aurora (SCHROTER, 1789) Apra Harbor Anae Island Xs photographs by Jean M. Cate THE VELIGER, Vol. 12, No. 1 [C. N.CarE] Plate 18 Figure 12 Figure 13 Lyncina argus (LINNAEUS, 1758) Lyncina lynx (LINNAEUS, 1758) Asan Point x4 Merizo Figure 14 Figure 15 Lyncina vitellus (LINNAEUS, 1758) Lyncina ventriculus (LAMARCK, 1810) Merizo oF Orote Point x 2 Figure 16 Figure 17 Lyncina schilderorum (IREDALE, 1939) Lyncina carneola carneola (LINNAEUS, 1758) Piti Bay xX 12 Tumon Bay Xx 12 photographs by Jean M. Carte Tue VELIGER, Vol. 12, No. 1 [C. N.CateE] Plate 19 Figure 18 Figure 19 Lyncina carneola leviathan SCHILDER & SCHILDER, 1927 Chelycypraea testudinaria (LINNAEUS, 1758) Adelup Point DX Asan Point x 4 Figure 20 Figure 21 Luria isabella (LINNAEUS, 1758) Pustularia mariae SCHILDER, 1927 Hilaan Point Reef x Apra Harbor X 3 Figure 22 Figure 23 Pustularia bistrinotata SCHILDER & SCHILDER, 1937 Pustularia margarita (D1LtwyN, 1817) Apra Harbor X g Piti Bay Sy photographs by JEAN M. Cate THE VELIGER, Vol. 12, No. 1 [C. N.Cate] Plate 20 Figure 24 Figure 25 Pustularia globulus (LINNAEUS, 1758) Pustularia childreni (Gray, 1825) Apra Harbor xX 3 Apra Harbor X 3 Figure 26 Figure 27 Monetaria annulus (LINNAEUS, 1758) Monetaria moneta (LINNAEUS, 1758) Agat Bay XX Oy Merizo a2 Figure 28 Figure 29 Naria irrorata (Gray, 1828) Erosaria becki (GAskoIn, 1836) Asan x 6 Asan x 5a photographs by Jean M. Carte Tue VELIGER, Vol. 12, No. 1 [C. N.CateE] Plate 21 Figure 30 Figure 31 Erosaria labrolineata (GaskoINn, 1849) Erosaria helvola (LINNAEUS, 1758) Piti Bay X83 Figure 32 Figure 33 Erosaria caputserpentis (LINNAEUS, 1758) Erosaria poraria (LINNAEUS, 1758) N CS Beach x 14 Pago Bay xX 3 Figure 34 Figure 35 Erosaria erosa (LINNAEUS, 1758) Staphylaea staphylaea (LINNAEUS, 1758) Asan DS See Apra Harbor x 25 } photographs by Jean M. Cate Tue VELIcER, Vol. 12, No. 1 [C. N.Cate] Plate 22 Figure 36 Figure 37 Staphylaea limacina (LAMARCK, 1810) Nucleolaria nucleus (LINNAEUS, 1758) Asan xX 12 Apra Harbor XK @ Figure 38 Figure 39 Erronea onyx (LINNAEUS, 1758) Erronea ovum (GMELIN, 1791) Apra Harbor Kes Apra Harbor xX 2 Figure 40 Figure 41 Erronea errones (LINNAEUS, 1758) Erronea cylindrica (Born, 1778) Apra Harbor DX sity Hilaan Point Reef x1F photographs by Jean M. Catz THE VELIGER, Vol. 12, No. 1 {C. N.Carte] Plate 23 Figure 42 Figure 43 Erronea caurica (LINNAEUS, 1758) Erronea listeri (Gray, 1824) Tumon Bay x 14 Apra Harbor xX 3 Figure 44 Figure 45 Notadusta punctata (LINNAEUS, 1758) Palmadusta asellus (LINNAEUS, 1758) Asan x 4 Apra Harbor XS 3 Figure 46 Figure 47 Palmadusta clandestina (LINNAEUS, 1767) Palmadusta lutea (GMELIN, 1791!) Apra Harbor XK B N CS Beach x5 photographs by Jean M. Catz Tue VELIGER, Vol. 12, No. 1 [C. N.CatE] Plate 24 Figure 49 Palmadusta ziczac (LINNAEUS, 1758) Palmadusta gracilis (GaAskoIN, 1849) Asan Point xX 2% Apra Harbor xX 3 Figure 50 Figure 51 Palmadusta fimbriata (GMELIN, 1791) Bistolida teres (GMELIN, 1791) Piti Bay Reef x 4% Apra Harbor x 1% Figure 52 Figure 53 Bistolida goodalli fuscomaculata (PEASE, 1865) Bistolida kieneri (Hiparco, 1906) N CS Beach xX 4 N CS Beach xX 4 photographs by Jean M. Carte , f ie) \ t ay v “i ‘ J ’ Z . , ; I oo ; i a Ma , a mi ty ‘ 7 te bh | 4 sat - 7 r — Ply - ee int atl : met ss y Ui i et t ees Hy ¥, q = * my ‘ 5 3 you 7) se SS aly, bee ane a v BAY) a vii Ti = Tue VeuicrEr, Vol. 12, No. 1 [C. N.Cate] Plate 25 Figure 54 Figure 55 Bistolida hirundo (LinNAEUS, 1758) Bistolida stolida (Linnagus, 1758) Apra Harbor Xx at Apra Harbor x 2 Figure 56 Figure 57 Cribrarula chinensis (GMELIN, 1791) Cribrarula cribraria (LINNAEUS, 1758) Tumon Bay XX they Apra Harbor XxX 2f photographs by Jean M. Cate 4 - ; j rt i Ny 2 4 ; 2 i : z - . t ; za ~ of ; 4 vy r d : ae ; , : , 4 + ‘ . a ony y. we = 33 « - a = ( = ; é f 5: é 1 2 " 0 4 f f i R = ; 4 ’ ar \ Ls _ oe . mets = : : 3 ro te $ , in ux - ‘ bs Ny x “a : : : ; a “ : : : , - 5 ' , 3 on = = ——<_ = ~ bo” Vol. 12; No. 1 THE VELIGER Page 127 25. Erronea (Melicerona) listeri (Gray, 1824) Zool. Journ. 1: 384 (Plate 23, Figure 43) Localities: 7 44 45 60 Largest shell: 17.6 10.0 13 16 15 Smallest shell: 9.6 7.6 5.7 15 16 This species is uncommon to rare, with most of the shells being collected in Apra Harbor; it is not found very often anywhere. 26. Notadusta punctata (LinnaEvs, 1758) (Plate 23, Figure 44) eocalities: 2 3 7 23 44 45 Largest shell: 14.6 8.1 TS) 22 20 Smallest shell: 10.5 5.6 4.8 20 21 The shells of this species are small when compared with those from the more western Pacific region populations. The species is uncommon in Guamanian waters and is rarely collected. The island collections appeared not to have more than one or two specimens in them. 27. Palmadusta (Palmadusta) asellus (LinNAEUS, 1758) (Plate 23, Figure 45) Locality: 7 Shell data: 17.8 10.2 8.0 18 18 The shell listed above was collected circa 1955 by B. J. Smith of Agama. It is now in the Cate collection. The species must be considered very rare in Guamanian tidal areas. As I do not have first-hand information concerning this species, it will have to be considered as provisionally from Guam. 28. Palmadusta (Palmadusta) clandestina (LINNAEUS, 1767) (Plate 23, Figure 46) Localities: 7 44 45 Largest shell: 2 9.6 7.8 22 17 Smallest shell: 15.1 8.1 6.7 22 17 Although almost every local collector has this species in his collection, it is not a common species. It occurs on the reefs and is oftcn found in the Apra Harbor - Asan - Piti area. 29. Palmadusta (Palmadusta) lutea lutea (GMELIN 1791) (Plate 23, Figure 47) Locality: 35 Shell data: 11.4 6.5 os) 17 16 I had the pleasure of being in Agafia on the day this first reported specimen was found on November 18, 1966 on the reef at NCS Beach by Floyd Miller. We were visiting at his home upon the return from a collecting trip and he handed me the shell, still containing the living animal, for identification. Since then another specimen has been collected in the same general locality by Mrs. Phyllis Eliason. As can be seen from the data given here, the shell is unusually small for the species, though it was fully mature, with a normal color patter) 30. Palmadusta (Palmadusta) ziczac (LinnaEus, 1758) (Plate 24, Figure 48) Localities: 2 3 44 45 Largest shell: 18.8 11.5 9.0 17 16 Smallest shell: 16.1 10.0 8.1 16 15 This species is found only rarely, less than a dozen specimens presently being known from this area. Most shells are live-collected; however, the smallest one listed above (Cate coll. no. C951) is a dead beach: Irift find at Asan-Piti. According to Warp (1956) only 2 live-col- lected specimens were in Guam collections at that time; it is still a rare species. 31. Palmadusta (Purpuradusta) gracilis (Gasko1n, 1849) (Plate 24, Figure 49) Localities: 7 44 45 Largest shell: Wel OS) 8.2 16 15 Smallest shell: 13.4 8.0 6.6 16 16 Apia Harbor seems to be the local center of distribution for this uncommon species. It is found on the reefs and under coral rubble. I did not note any other island localities for this species in the local Guam collections. 32. Palmadusta (Palmadusta) fimbriata (GMELIN, 1791) (Plate 24, Figure 50) Localities: 2 3 7 15 44 45 Largest shell: H2r2 7.0 ond, 18 18 Smallest shell: 11.8 6.3 4.9 18 17 Page 128 This species is not very common at Guam, but collec- tions show it to be widely distributed among the island’s reefs. 33. Bistolida (Blasicrura) teres teres (GMELIN, 1791) (Plate 24, Figure 51) Localities: 2 3 6 7 17 24 30 44 45 55 Largest shell: SRS 18.7 14.2 25 25 Smallest shell: 28.4 15.5 11.8 24 23 This species is fairly common at Guam with a wide distribution among the offshore reefs. 34. Bistolida (Blasicrura) goodalli fuscomaculata (PEASE, 1865) Proc. Zool. Soc. London 1865: 515 (Plate 24, Figure 52) Localities: 35 44 Shell data: ied 6.7 5:3 21 17 Shell small, strong, ovate, humped; terminals well de- veloped, barely protruding, distinctively formed; right margin calloused, angled, semi-shouldered, with minute indentations along marginal edge; aperture almost straight, narrow; teeth numerous, very fine, short, barely reaching onto outer lip, not at all on columella; fossula rudimen- tary, barely evident, denticulate; primary shell color grey- beige, finely speckled with chestnut-brown spots over dor- sum, larger spots thickly concentrated along both margins, with a large chestnut-brown dorsal blotch, and smaller supporting color blotches; 4 large, well defined dark brown spots adorn the sides of the terminal openings, two at each end of shell (quadrimaculate); terminals, base, teeth, and interstices grey-beige. There are two synonyms for this species: Cypraea adelinae Roperts, 1885 (Tryon, Man. Conch., 7: 168; pit. 4, figs. 46, 47) and Cypraea dautzenbergi Hwatco, 1907 (Mem. Acad. Cienc. Madrid, Cypraea: p. 362). The first Guam shell of this seldom seen subspecies was collected by Mrs. Phyllis Eliason, Agana, at NCS Beach; a second specimen has now been found at Piti Bay. This subspecies is rare enough so that, with a fresh-collected specimen at hand, it seemed desirable to redescribe the shell. It is distinct from the nominate species, B. (B.) g. goodalli (SowrrBy, 1832), more commonly encountered at the Cook Islands in southwest Polynesia, which is smaller, more slender, and does not have the brown ter- minal maculations and the large, very dark dorsal blotch of this subspecies. THE VELIGER Vol. 12; No: 1 35. Bistolida (Bistolida) kieneri (Hmauco, 1906) (Plate 24, Figure 53) Localities: 7 27 35 55 Largest shell: 134. 75° ° 69 ive amet Smallest shell: 13:5 74 5.7 17 414 This species is apparently a relatively new addition to the cowrie fauna of Guam, where it was unknown to collectors prior to 1960. Since then, however, a number of these animals have been collected, and dead shells have been found in beach drift. The species remains uncommon to rare. 36. Bistolida (Bistolida) hirundo (Linnaeus, 1758) (Plate 25, Figure 54) Localities: 2 3 7 Largest shell: AOR § OO WM ie Smallest shell: 7 aye) 4.1. O18 14 This uncommon species occurs at the Apra Harbor reef and at Asan reef. Its occurrence elsewhere at Guam is:as yet unknown. 37. Bistolida (Bistolida) stolida (LinNAEus, 1758) (Plate 25, Figure 55) Localities: 2 3 7 23 35 44 45 Largest shell: 27.8 16.5 12.8 20 20 Smallest shell: 25.6 14.7 11-1 19 17 At one time this species was thought to be very rare in Guamanian waters, but subsequent discovery and collec- tions now place this form nearer the common group. Most local collections contain from 2 to 3 specimens. 38. Ovatipsa chinensis chinensis (GMELIN, 1791) (Plate 25, Figure 56) Localities: 2 3 5 7 10 44 45 47 55 Largest shell: 340, 194 150) 1omuumls Smallest shell: 31.0 176 138 18 18 This species, though uncommon, has a fairly wide distri- bution on most of the island’s reefs. The morphological characteristics of the Guam shells are. more closely re- lated to the Philippine form, rather than to those of the Hawaiian form (see Cate, 1965, 1966) Vol. 12; No. 1 39. Cribrarula cribraria (LinNAEuS, 1758) (Plate 25, Figure 57) Localities: 2 3 4 7 44 45 Largest shell: 35.5 17.0 13.4 21 21 Smallest shell: 13.5 ici 6.1 il7/ 15 Apra Harbor and Tumon Bay are two well known collecting localities for this uncommon species. It is not found very often; it seems to prefer living deep within the recesses, caves, and crevices of the reefs, and, being more active nocturnally, it is rarely seen. See ScHILDER, 1967 (p. 103) for an explanation of the usage of the generic name Cribrarula. 40. Pustularia (Annepona) mariae ScHILDER, 1927 (Plate 19, Figure 21) Localities: 2 3 7 37 44 45 Largest shell: 17.0 il 10.3 43 27 Smallest shell: 13.1 8.8 8.2 32 21 This species is rare in collections in Guam and is repre- sented entirely, I believe, by dead, beach shells only. The localities listed here indicate a deep water habitat; practi- cally nothing is known at present of the animal’s living habits. 41. Pustularia (Pustularia) bistrinotata SCHILDER & SCHILDER, 1937 (Plate 19, Figure 22) Localities: 7 37 44 45 48 Largest shell: 19.2 758) 10.8 28 22 Smallest shell: 16.4 9.9 8.9 30 21 This species is uncommon; it is most often obtained as a beach-rolled shell in which condition it has been fre- quently mistaken for Pustularia margarita (Dittwyn, 1817), a species without dorsal pustules, a condition I observed in the collections at Guam. 42. Pustularia (Pustularia) margarita (Di1LLwyn, 1817) (Plate 19, Figure 23) Localities: 7 44 45 Largest shell: 20.0 12.8 12.1 30 25 Smallest shell: 15.6 9.7 8.7 27 24 Like the preceding species, this one is uncommon in Guam waters, with only an occasional shell being found on the beaches, usually after a storm or high wind. The specimens listed are from the Cate collection (larger shell), and the Jean Kauanui collection (smaller shell). Both THE VELIGER Page 129 specimens are accompanied by labels giving Apra Harbor as the collecting locality. 43. Pustularia (Pustularia) globulus (Linnazus, 1758) (Plate 20, Figure 24) Localities: 7 15 Largest shell: 17.8 11.2 10.0 36 26 Smallest shell: 17.3 10.5 9.3 33 29 This uncommon species is presently known only from a few localities at Guam. While it is represented mostly by dead, beach shells, occasionally a living animal is found. Apra Harbor and Cetti Bay provide most specimens. 44. Pustularia (Ipsa) childreni (Gray, 1825) (Plate 20, Figure 25) Localities: 2 3 7 44 45 53 54 Largest shell: 22:3 15.3 12.5 41 25 Smallest shell: 14.9 10.0 8.0 33 22 A rare species at Guam, it is presently known only from beach-collected specimens, obtained mostly after a storm. As it apparently lives in deeper water, it is beyond the reach of most local collectors. 45. Monetaria (Ornamentaria) annulus annulus (Linnaeus, 1758) (Plate 20, Figure 26) Localities: 2 3 5 6 7 13 27 30 31 37 44 45 55 60 65 Largest shell: 21.1 16.2 11.0 13 10 Smallest shell: 15.0 10.4 Ue) 11 9 This species, unlike the following one, is common, but not really abundant. It is found both in the shallow water coral hills and on the sand flats that are barely covered with water at low tide. 46. Monetaria (Monetaria) moneta (LinnaEus, 1758) (Plate 20, Figure 27) Localities: 2 35 7 13 27 30 31 35 36 37 44 45 55 60 65 Largest shell: 26.5 17.0 12.2 15 12 Smallest shell: 16.8 eS 7.8 12 11 This species is almost ubiquitous on the shallow sand flats, on the reefs, around coral rubble, and on rocks. We found it to be plentiful in the intertidal areas of Agafia Bay and it seemed to live in areas where there were no other mollusks present, except for a single bivalve species, which remains unidentified. Page 130 47. Naria irrorata (Gray, 1828) (Plate 20, Figure 28) Localities: 2 3 44 45 Largest shell: 10.9 6.3 4.8 16N Smallest shell: il 5.0 3.7 16 14 This relatively rare species is found in the Asan-Piti area inhabiting dead coral heads that are subjected to a continual pounding surf. The Guamanian shells seem to be small and narrow for the species, but possess the normal color, spotting and other morphological characters of the species. 48. Erosaria (Paulonaria) beck (Gasxotn, 1836) (Plate 20, Figure 29) Localities: 2 3 7 44 45 Largest shell: 10.5 5d 4.9 20 17 Smallest shell: 8.8 5.0 4.2 17 17 As of June, 1959, only one live-collected specimen was known at Guam, but in recent years an occasional speci- men has been found. This rare species is represented in only a few local collections. Apra Harbor and Asan are the localities where it has been taken most frequently. 49. Erosaria (Erosaria) labrolineata labrolineata (Gasxoin, 1849) (Plate 21, Figure 30) Localities: 2 3 7 44 45 60 Largest shell: eal 10.0 7.9 18 17 Smallest shell: 14.4 8.5 6.7 16 16 A very rare species, it is known mostly from dead shells picked up in the beach drift. Only 2 or 3 live-taken speci- mens, from USO Beach and Piti Reef, are known at present. 50. Erosaria (Erosaria) helvola (Linnaeus, 1758) (Plate 21, Figure 31) Localities: 2 3 7 16 31 35 36 44 45 Largest shell: 21.6 17.2 12.0 17 14 Smallest shell: 14.5 9.4 7.2 15 11 Though this is a fairly common species, it is never seen in any quantity. It occurs in the reef areas at certain locations and is collected mostly at night. THE VELIGER Vol. 12; No. 1 51. Erosaria (Erosaria) caputserpentis caputserpentis (Linnaeus, 1758) (Plate 21, Figure 32) Localities: 2 3 5 7 10 13 15 16 20 23 27 30 31 35 36 37 43 44 45 47 48 52 53 55 59 60 Largest shell: 33ml 25.9 16.4 17 15 Smallest shell: 24.0 18.2 12.3 15 14 As can be seen by the number of localities listed, the species is common and ranges over most of the island’s reefs and rocky areas. 52. Erosaria (Erosaria) poraria (Linnagus, 1758) (Plate 21, Figure 33) Localities: 2 3 7 35 36 43 44 45 65 Largest shell: 18.5 14.4 10.3 18 16 Smallest shell: 13.4 9.1 6.8 20 13 This fairly widely distributed species is found on the reefs and, on occasion, in the beach drift; however, it is not common wherever it occurs at Guam. 53. Erosaria (Erosaria) erosa erosa (Linnagus, 1758) (Plate 21, Figure 34) Localities: 235 7 13 15 27 31 44 45 47 52 54 55 60 65 Largest shell: ends) BBE) Wes 21 15 Smallest shell: 21.4 13.0 9.6 18 11 This is the most commonly found cowrie species at Guam, where it inhabits all the reef areas, living on the algae-covered coral and under rocks and coral boulders, and even on exposed tidal sand flats. 54. Staphylaea staphylaea (LinNAEus, 1758) (Plate 21, Figure 35) Localities: 7 44 45 Largest shell: 20.6 1225) 10.0 20 23 Smallest shell: 18.9 11.7 9.3 22 16 At present this uncommon species at Guam seems to to be restricted in its distribution to the central-western Apra-Harbor-Piti-Asan area; only on occasion is the shell found. Vol. 12; No. 1 THE VELIGER Page 131 55. Staphylaea limacina (Lamarck, 1810) Cate, Criwrorp Newt continued 1967. The cowries of the Ryukyu Islands. The Veliger (Plate 22, Figure 36) 10 (1): 13-41; plt. 3; 2 maps (1 July 1967) Localities: 7 44 45 Largest shell: 28.2 16.8 14.5 25 24 Smallest shell: 25.0 14.0 6.8 25 24 The species is rare at Guam; when found, it is in the Apra Harbor-Asan-Piti area on the reefs, curiously in the same habitat as the preceding species. 56. Nucleolaria nucleus nucleus (LINNAEUS, 1758) (Plate 22, Figure 37) Localities: 7 30 51 Largest shell: 25.4 15.1 12.3 27 21 Smallest shell: 18.0 11.6 10.0 23 20 This rare species is found now and then in the reef area of Apra Harbor; it is represented by only a very few specimens in the local island collections. The shells seem to be generally smaller than those of Japan and the Ryukyu Islands; the Philippine form also seems to be shorter and broader than this shell. LITERATURE CITED Cate, CrawForp NEILL 1965. | Hawaiian cowries. 4-10; 4 maps 1966. Philippine cowries. pits. 32-45; 3 text figs.; The Veliger 8 (2): 45-61; plts. (1 October 1965) The Veliger 8 (4): 234 - 264; 1 map. (1 April 1966) IncrAM, WILLIAM Marcus 1938. Cypraeidae from Guam The Nautilus 52 (1): 5-7 (July 1938) Kay, EvizaBetH ALISON & Ciirton STOKES WEAVER 1962. Cypraeidae. Hawaiian marine mollusks 2 (20) : 75 - 78 (15 November 1962) 1963. Cypraeidae. Hawaiian marine mollusks 2 (21): 79 - 82 (1 February 1963) 1963. Cypraeidae. Hawaiian marine mollusks 2 (22): 83 - 86 (1 May 1963) 1963. Cypraeidae. Hawaiian marine mollusks 2 (23): 87 - 90 (1 August 1963) 1963. Cypraeidae. Hawaiian marine mollusks 2 (24): 91 - 94 (1 November 1963) 1964. Cypraeidae. Hawaiian marine mollusks 2 (25): 95 - 98 (1 February 1964) ScHILDER, FRANz ALFRED 1965. Geographical distribution of cowries. The Veliger 7 (3): 171 - 183; 2 maps (1 January 1965) 1968. The generic classification of cowries. The Veliger 10 (3) : 264 - 273 ScHILpER, Franz ALFRED & Maria SCHILDER 1966. The size of ninety-five thousand cowries. 8 (4): 208 - 215 ScHILDER, Maria & FRANZ ALFRED SCHILDER 1967. Studies on East Australian cowries. 10 (2): 103-110; 9 tables Eviason, PHYLLIS & JEAN ALLEN 1959. _A list of Guam shells. (privately circulated, unpublished list of Guam mollusk species, including the cowries) Warp, HERBERT 1956. (privately circulated list of Guam cowries; see remarks for Palmadusta ztczac) (1 January 1968) The Veliger (1 April 1966) The Veliger (1 October 1967) Page 132 NOTES & NEWS Notes on the Collection of Tritonia festiva (STEARNS, 1873) from the Seas of Japan (Gastropoda : Nudibranchia) BY KIKUTARO BABA Biological Institute, Osaka Kyoiku University Tennoji, Osaka, Japan (1 Text figure) Tritonia festiva (STEARNS, 1873) Latenbranchiaea festiva STEARNS, 1873. — Monterey Bay. Tritonia festiva, Marcus, 1961. — Tomales Point. Duvaucelia festiva, MacFaRLanp, 1966. — Monterey Bay. Sphaerostoma undulata O’DonocuuE, 1924. — Vancouver Is- land region; O’DonocHuE, 1926 (list). Duvaucelia undulata var. muroranica Basa, 1940. — Muroran (Hokkaido) ; Basa, 1957 (list). Tritonia reticulata BercH, 1881. — Japan. Here it is intended to give a summary of local informa- tion gained from the study of our specimens of Tritonia festiva which has, following MacFarLanpb (1966) priority over T. reticulata Bercu, 1881. Possibly it has also priority over Duvaucelia undulata var. muroranica. The study ma- terial is listed below: Specimens no. 1-4. Off Niigata, Japan Sea side of Japan, 70m (August 2, 1958, coll. by Dr. G. Kato). Sp. no. 5. Sado, Japan Sea side, shore (May 9, 1956, coll. by Dr. Y. Honma). Sp. no. 6 - 10. Sado (May 20, 1966, coll. by Dr. I. Usuki). Sp. no. 11. Abugashima, Toyama Bay, Japan Sea side, shore (July 23, 1951, coll. by Mr. T: Abe and the author). Sp. no. 12. Abugashima, shore (April 29, 1967, coll. by Mr. T. Abe). Sp. no. 13. Off Hayama, Sagami Bay, Pacific side of Japan (Jan. 18, 1966, coll. by Biological Laboratory, Imperial Household). Sp. no. 14-16. Off Hayama (February 6, 1967, collector as above). These specimens ranged usually from 20 mm to 50 mm in length, while the largest (specimen no. 14) showed the maximum length of 75 mm in the preserved state. In them the general ground colour of the back and sides THE VELIGER Vol. 12; No. 1 varied from a translucent whitish (specimen no. 11) or pale yellow (specimens no. 6, 7) to as far as a deep orange-red (specimens no. 5, 8 - 10, 13 - 16) or rather a purplish red (specimens no. 1 -4 and 12). In every one of the specimens there occurred prominent figures of opaque white on the back. The maximum radular formu- lae for the specimens dissected were 24 x 30:1-1:1-30 (specimen no. 11, body length 15mm), 35 x 40:1-1-1-40 (specimen no. 5, body length 20 mm), 45 x 80-1-1-1°80 (specimen no. 3, body length 35mm), and 50 x 90-1-1- 1-90 (specimen no. 16, body length 58 mm). The details of the radular teeth and jaw-plates were as usual in the genus Tritonia. The urn-shaped penis was proved to have an apical papilla in the centre of the terminal disc (speci- mens no. 3, 5, and 16). Nn A conclusive statement may follow that our specimens, though subject to variation in some respects, are possessed of two of the eminent characteristics of Tritonia festiva from the type locality: the first is the: presence’ of. the opaque white figures on the back, and the second lies in the formation of the apical papilla of the: penis. This species, of which the type is known to be of a créam white, has thus a distribution in the Pacific North America and Japan, but so far there has been no record of collecting of this form from the regions between the two. ACKNOWLEDGMENTS I wish to express my thanks to Dr. Genji Kato, Japan Sea Regional Fisheries Research Laboratory; Dr. Yoshi- haru Honma, Niigata University; Dr. Itaru Usuki, Sado Marine Biological Station; Mr. Takeo Abe, Takaoka Se- nior High School; and The Chief of the Biological La- boratory, Imperial Household, for their generosity in placing valuable collections made by them at my disposal for comparative study. I wish to thank Mr. Clinton L. Collier, San Diego, who kindly gave me facilities to refer to some of the late O’DoNoGHUE’s papers on the nudi- branchiate Mollusca from the Vancouver Island region. I (on facing page —>) Figure 1 Tritonia festiva (STEARNS, 1873) A. Animal from above. Length 15 mm; specimen no. 11. B. Left jaw from outside (40), specimen no. 11. C. A half-row of radula (X200), specimen no. 11. D. A half-row of radula (X50), specimen no. 16. E. Distal part of male organ (X7), specimen no. 16. a) penis; b) penis sac; c) apical papilla; d) vas deferens F. Terminal disk of penis. Specimen no. 3. a) opening of vas deferens G. Terminal disk of penis. Specimen no. 5. THE VELIGER Page 133 Vol. 12; No. 1 Page 134 am obliged to Mr. Steven J. Long, Pismo Beach, Califor- nia, for a copy of the work by STEARNS. LITERATURE CITED Basa, KikuTar6 oo 1940. Some additions to the nudibranch fauna of the northern part of Japan. Bull. Biogeogr. Soc. Japan 10 (6): 106 to 107. 1957. A revised list of the species of Opisthobranchia from the northern part of Japan. Journ. Fac. Sci. Hokkaido Univ. 6, Zool. 13 (1-4): 8- 14 Bercy, Lupwic SopHus RUDOLF 1881. Beitrage zur Kenntnif der japanischen Nudibranchien. Il. Verh. k. k. zool.-bot. Gesell. Wien 31: 23 - 34 MacFarianp, Frank Mace 1966. Studies of opisthobranchiate mollusks of the Pacific Coast of North America. Mem. Calif. Acad. Sci. 6: xvi + 546 pp.; 72 plts. (8 April 1966) Marcus, ERNST 1961. | Opisthobranch mollusks from California. The Veliger 3 (Supplement, pt. I) : 1-85; plts. 1-10. (Feb. 1, 1961) O’DonocHveE, CHarves H. 1924. Notes on the nudibranchiate mollusca from the Vancouver Island region, IV. Trans. Roy. Canad. Inst. 15 (1): 1 to 33; plts. 1, 2. 1926. A list of the nudibranchiate mollusca recorded from the Pacific coast of North America, with notes on their distribution. ‘Trans. Roy. Canad. Inst. 15 (2): 199-247. STEARNS, RoBperT EpwArRDS CaRTER 1873. Descriptions of a new genus and two new species of nudibranchiate mollusks from the coast of California. Proc. Calif. Acad, Sci. 5: 77 - 78 Range Extension of Tochuina tetraquetra (PALLAS, 1788) to Hokkaido, North Japan (Gastropoda : Nudibranchia) BY KIKUTARO BABA Biological Institute, Osaka Kyoiku University Tennoji, Osaka, Japan Tochuina tetraquetra (Pauias, 1788) Limax tetraquetra Patias, 1788. —Kurile Islands. Tritonia tetraquetra, Bercu, 1879. — Unalaska (Aleutian Is.) ; O’DonocuuE, 1922. — Victoria (Vancouver Island). Tritoniopsilla tetraquetra, ODHNER, 1936. Sphaerostoma tetraquetra, O’DonocHuE, 1926. THE VELIGER Vol..12; No. 1 Duvaucelia tetraquetra MacFaRuanp, 1966. — Petersburg (Al- aska) ; San Francisco Bay; Monterey Bay. Tritonia gigantea Bercu, 1904. — Unalaska (Alaska). Tritoniopsis aurantia Matrox, 1955. — Santa Catalina Island (Southern California) ; Marcus, 1961. In 1960 a single specimen of this notable species was col- lected by Dr. Minoru Imajima, formerly a member of the Shirikishinai Marine Biological Laboratory, Hokkaido Kyoiku University, from 140 meters depth off Shiriki- shinai near Hakodate, Hokkaido, Japan. As preserved, the animal was greatly damaged, but it showed the charac- teristics of the species in the thickly fringed rows of the gills on the back-margins, and in having an extremely large radula (90 X 220-1:220) consisting of a degraded unicuspidate central and simply hamate (not filiform) laterals. The total length of the body was more than 10 cm. From the above description it will readily be seen that this species constitutes one of those forms which cover in distribution the entire territory of the North Pacific from east to west. LITERATURE CITED Bercy, Lupwic SopHus RUDOLF 1879. On the nudibranchiate gastropod mollusca of the north Pacific ocean, with special reference to those of Alaska. Proc. Acad. Nat. Sci. Philadelphia, pt. 1; 71-132; plts. 1-8. 1904. Nudibranchiata, Tectibranchiata-Pectibranchiata. In: Semper, Reisen im Archipel der Philippinen. 9 (6), Lief. 1: 26 - 28 MacFar.anp, FRaNK Mace 1966. Studies of opisthobranchiate mollusks of the Pacific Coast of North America. Mem. Calif. Acad. Sci. 6: xvi + 546 pp.; 72 plts. (8 April 1966) Marcus, ERNST 1961. | Opisthobranch mollusks from California. ger 3 (Supplement, pt. 1): 1-85; plts. 1 - 10. Mattox, Norman T. 1955. Studies on the Opisthobranchiata: I. A new species of the genus Tritoniopsis from southern California. Bull. S. Calif. Acad. Sci. 54 (1): 8-13 OpuN_ER, Nits HjaLmMar 1936. | Nudibranchia Dendronotacea. A revision of the System. Mélanges Paul Pelseneer. Mém. Mus. Roy. d’Hist. Nat. de Belgique, Ser. II, Fasc. 3: 1057-1128; 1 plt.; text figs. 1-47. 1963. On the taxonomy of the family Tritoniidae (Mollusca: Opisthobranchia). | The Veliger 6 (1): 48-52 (1 July ’63) O’DonocHuE, CHARLES HENRY 1922. Notes on the nudibranchiate Mollusca from the Van- couver Island region. III. Records of species and distribution. Trans. Roy. Canad. Inst. 14 (1): 145 - 167; plts. 5, 6 1926. _A list of the nudibranchiate mollusca recorded from the Pacific coast of North America, with notes on their distribution. Trans. Roy. Canad. Inst. 15 (2): 199 - 247 Patras, P. S. 1788 Marina varia nova et rariora. Nova Acta Acad. Sci. Imp. Petropolitana 2. St. Petersburg, 1784. The Veli- Vol. 12; No. 1 THE VELIGER Page 135 Current Paleontological Investigations on Cenozoic Marine Mollusks of the West Coast of North America BY WARREN O. ADDICOTT U. S. Geological Survey, Menlo Park, California 94025 AND SABURO KANNO Tokyo University of Education, Tokyo, Japan THIS REPORT 'SUMMARIZES recently completed studies and work in progress on Cenozoic marine mollusks of the Pa- cific coast of North America. Investigations are arranged under several broad topical categories. Investigators are listed alphabetically under each category together with their institutional affiliation, if any, and current address. Many studies span more than one of these but space lim- itations have dictated against multiple listings. Certain non-paleontological research such as isotopic studies re- lated to age determination or paleoclimatic analysis is included. Stratigraphic terminology is that of the individ- ual workers. We are indebted to A. Myra Keen, N. FE Sohl, and E. C. Allison for reading, and commenting on, the manuscript. TAXONOMY Paleogene Caroe S. Hickman (Washington State University, Pullman, Wash- ington 99163) has completed a master’s thesis at the University of Oregon on the molluscan fauna of the Oligocene Eugene Forma- tion of western Oregon. Mrs, Hickman is currently preparing the dissertation for publication. Sasuro Kanno (Tokyo University of Education, Tokyo, Japan) recently concluded an 11-month visit at the U. S. Geological Survey in Menlo Park, California. He is completing a taxonomic-bio- stratigraphic manuscript on the late Oligocene to middle Miocene molluscan faunas of the Poul Creek and Yakataga Formations of the Gulf of Alaska. V. StanpisH MaAttory (University of Washington, Seattle, Wash- ington 98105) is planning to have several of his recent students’ theses dealing with Paleogene mollusks of western Washington re- written for publication in a museum-based monograph and novi- tate series at the University. 1 Publication authorized by the Director, U.S. Geological Survey A systematic study of Oligocene mollusks of the Pittsburg Bluff Formation of northwestern Oregon is being carried out by ELLEN J. Moore (San Diego Museum of Natural History, San Diego, California 92112). STanLey R. Primer recently completed a master’s thesis at the University of California (Berkeley, California 94720) on the mol- luscan fauna of the type Kirker Formation at Mount Diablo, California. He has published a preliminary report on the biostrati- graphy and correlation of the Kirker Formation. Harotp E. Voxes (Tulane University, New Orleans, Louisiana 70118) has completed a manuscript on the molluscan fauna of the upper Eocene and lower Oligocene Keasey Formation of north- western Oregon. Neogene Warren O. Appicotr (U.S. Geological Survey, Menlo Park, Cali- fornia 94025) has a paper in press on the taxonomy and biostrati- graphy of early and middle Miocene gastropods from the south- eastern portion of the San Joaquin basin, California. Included are systematic descriptions and illustrations of more than 180 early and middle Miocene gastropods. Otuwareyisota S. ADEGOKE (Ife University, Ibadan, Nigeria) has recently published reports on first occurrences of Swiftopecten, Penitella, Platyodon, and Mya in the California Tertiary. His doctoral thesis at the University of California is now in press; it includes systematic descriptions of Neogene mollusks of the north- western part of the San Joaquin basin, California. Epwin C. Atiison (San Diego State College, San Diego, Califor- nia 92115) continues his work on late Cenozoic mollusks of the eastern Pacific, including a study of Cenozoic species of Arca. Joun M. ArMENTROuT has completed a master’s thesis at the University of Oregon (Eugene, Oregon 97401) ; this paper reviews the molluscan fauna of the type Empire Formation (Pliocene) of Coos Bay, southwestern Oregon, based on extensive collections in the Department of Geology. Included in his study is an assemblage of middle Miocene mollusks from previously unreported exposures at Coos Bay. EuceEnE V. Coan is preparing for publication his recently completed doctoral thesis at Stanford University (Stanford, California 94305) on late Cenozoic and modern Tellinacea of the northeastern Pacific and arctic Alaska. The long awaited manuscript on Pliocene mollusks of the San Diego Formation, part of a series of reports on the Geology and Paleontology of the San Diego, California area by Leo G. HeErt- LEIN (California Academy of Sciences, San Francisco, California 94118) is ready to go to press. Utysses S. Grant, IV (University of California, Los Angeles, California 90024) is co-author. HErt- LEIN has begun work on a report on Pliocene mollusks of the Gala- pagos Islands. GrorcE L. KENNEDY (San Diego Museum of Natural History, San Diego, California 92112) has completed a systematic study of fossil Pholadidae of the eastern Pacific and is preparing a manu- script for publication. FE Stearns MacNem (5958 Prather Drive, Fort Myers, Florida 33901), formerly of the U.S. Geological Survey, is continuing his Page 136 THE VELIGER Vol. 12; No. 1 studies on Cenozoic mollusks of Alaska. He recently published a monograph on the Cenozoic Pectinidae of Alaska. Pliocene molluscan assemblages from the Imperial Formation near San Gorgonio Pass, southern California, are being studied by Micuaet A. Murpny and his students at the University of Cali- fornia (Riverside, California 92507). Ricuarp Rector, a student at the University of Washington (Seattle, Washington 98105), has completed a thesis dealing with mollusks of the Pliocene Quillayute Formation of the western Olympic Peninsula, Washington, and is currently rewriting it for publication. Takeo Susuxki (University of California, Los Angeles, California 90024) continues his interest in middle Miocene mollusks of the type Topanga Formation, southern California. Pleistocene S. Stirtman Berry (1145 West Highland, Redlands, California 92373) is continuing his descriptive studies of Pleistocene and living warm water mollusks of the Gulf of California, western Baja California, and southern California. Wituiam K. Emerson (American Museum of Natural History, New York, N. Y. 10024) is working on Pleistocene and. modern mol- lusks of the Gulf of California and the Pacific coast of Baja Cali- fornia. He has several recently published reports on gastropod genera; many of these deal with the Muricidae. GeorcE P. Kanaxorr (Los Angeles County Museum of Natural History, Los Angeles, California 90007) continues his interest in Pliocene and Pleistocene mollusks of southern California, concen- trating, at the present time, on the molluscan fauna of the lower Pleistocene Lomita Marl. His collections from the Pliocene San Diego Formation have provided much of the material for Leo G. HERTLEIN’s pelecypod monograph. J. ALDEN SUTHERLAND, also of the Museum, has been assisting KaNnaxkorF in field excavation and study of early Pleistocene mollusks from near Newport Bay, southern California. SuTHERLAND has recently begun intensive collecting of middle Miocene material from the Kern River area, central Cali- fornia. Jere H. Liprs (University of California, Davis, California 95616) has several recent publications on the Pleistocene history and fora- miniferal and molluscan paleoecology of insular faunas of the Southern California Borderland; two of the reports were co-authored by James W. VALENTINE of the same institution. General Ricwarp C. ALiison (University of Alaska, College, Alaska 99735) is studying Cenozoic Turritellidae of the eastern Pacific. He and Otuwareyisota S. ApEGOKE (Ife University, Ibadan, Nigeria) have completed a report on a new early Tertiary turritellid genus from the Pacific coast. WituraM K. Emerson (American Museum of Natural History, New York, N. Y. 10024) is continuing his studies on Cenozoic scapho- pods of the Pacific coast. A. Myra Keen (Stanford University, Stanford, California 94305) has written up many of the pelecypod families for the Treatise on Invertebrate Paleontology; the pelecypod volumes are now in press. She has also summarized the Archeogastropoda and several super- families in the Mesogastropoda and Neogastropoda for the second gastropod volume of the Treatise. She has been assisted in this work by EucEne V. Coan and other students. Currorp M. Netson (Cabrillo College, Aptos, California 95003) has begun work on a Ph. D, dissertation on Cenozoic Neptunea of the eastern Pacific at the University of California, Berkeley. Wits P. PopeNoE (University of California, Los Angeles, Califor- nia 90024) is working on opisthobranch gastropods for the Treatise on Invertebrate Paleontology. He is completing a joint study with micropaleontologist RoperT M. KLEINPELL (University of Califor- nia, Berkeley) on rates of evolution in tropical families in relation to Lyellian correlation. GerorcE E. Rapwin (San Diego Museum of Natural History, San Diego, California 92112) is writing a monograph on the Columbel- lidae of the eastern Pacific: ARNoLD Ross, of the same institution, is engaged in a systematic study of ectocommensals of Cenozoic mollusks. Atiyn G. Smiru (California Academy of Sciences, San Francisco, California 94118) is continuing his study of fossil chitons. Jupiru S. Terry (Stanford University, Stanford, California 94305) is preparing a manuscript on the cymatiid genera Argobuccinum, Fusitriton, and Priene from her recently completed doctoral thesis. She recently published a report describing the late cee genus Mediargo. WENDELL P. Wooprinc (U.S. National Museum, Washington, D. C. 20560) has completed the manuscript for the last part of: his four-part monograph on the geology and middle Eocene to early Pliocene gastropods of the Canal Zone and adjoining parts of: Panama (U.S. Geological Survey Professional Paper 306A-D). BIOSTRATIGRAPHY Warren O. Appicott (U.S. Geological Survey, Menlo Park, Cali- fornia 94025) has a manuscript in press on Pliocene molluscan faunas of the central Santa Cruz Mountains, California, and their paleogeographic significance. He is working on molluscan faunas from the upper Miocene Montesano Formation of southwestern Washington, the type Temblor Formation of central California. and lower and middle Tertiary formations of the Santa Monica Mountains, southern California. Otuwareyisoia S. ADEGOKE (Ife University, Ibadan, Nigeria) has a manuscript in press, based on his Ph. D. thesis, on’ the molluscan biostratigraphy of the classic Miocene and Pliocene sequences of the Coalinga and Reef Ridge sections of the western portion of the San Joaquin basin, California, originally studied by RALPH ARNOLD in 1909. KennetH W. Cirtacks and Aan R. Ormiston (Pan American Research Laboratory, Tulsa, Oklahoma '74103) have been working on the biostratigraphy of middle and upper Tertiary molluscan faunas of the Gulf of Alaska and the Alaska Peninsula. Eucene A. FrirscHE (San Fernando Valley State College, North- ridge, California 91326) is completing work on a Ph. D. disserta- tion at the University of California, Los Angeles, on the biostrati- graphy and taxonomy of Miocene molluscan faunas of the Sierra Madre Mountains, southern California. Cuartes R. Givens (University of Georgia, Athens, Georgia 30601) is adapting for publication his recently completed Ph. D. disserta- Vol. 12; No. 1 tion at the University of California, Riverside, on Eocene molluscan biostratigraphy of the Transverse Ranges, California. Givens has published a preliminary report reaffirming the validity of the four Eocene stages (Capay, Domengine, Transition, and Tejon) proposed by B. L. Crank and H.E. Voxes in 1936. Sapuro Kanno (Tokyo University of Education, Tokyo, Japan) is describing the middle Tertiary faunal sequence of the Gulf of Alaska based mainly on collections made during the summer of 1968 at Cape Yakataga. Frank H. Kirmer (Humboldt State College, Arcata, California 95521) is continuing work on Neogene mollusks and associated marine vertebrates of Cedros Island, Baja California. Scotr McCoy, Jr. (Phillips Petroleum Corp., Bartlesville, Okla- homa 74004) is studying the Tertiary molluscan biostratigraphy and paleoecology of the Alaska Peninsula and Gulf of Alaska. He is preparing a manuscript describing a new species of Pterynotus from the middle Tertiary Poul Creek Formation. Rosert G. McWitutaMs (Miami University, Oxford, Ohio 45056) recently completed a doctoral dissertation on Eocene and Oligocene biostratigraphy of central western Oregon including a thorough re-evaluation of older work on marine mollusk faunas. He has a manuscript in progress on mollusks of the Eocene Crescent For- mation and is planning a report on mollusks of the type Twin River Formation. C. Percy Strone, a University of Washington graduate student, has completed a manuscript on middle Tertiary mollusks and forami- nifers from southwestern Washington. Joun G. Vepper (U.S. Geological Survey, Washington, D.C. 20242) has recently published a detailed geological map of the intertonguing marine and nonmarine Tertiary section of the eastern part of the Caliente Range, California, and is now working on the molluscan biostratigraphy in collaboration with continental vertebrate and foraminiferal specialists. This study is expected to provide greatly improved standards for provincial Miocene corre- lation, VEDpDER is extending his field investigations to the nearby portion of the Temblor Range and San Rafael Mountains. He is also completing a biostratigraphic report on late Cenozoic mollusks of the southwestern part of the Los Angeles basin, California. Donato W. Weaver (University of California, Santa Barbara, California 93106) and his students are preparing a summary report on the geology and paleontology of the Channel Islands off south- ern California. Included will be new biostratigraphic data on Eocene and Miocene molluscan faunas. PALEOECOLOGY Joun W. Evans (Memorial University of Newfoundland, St. John’s, Newfoundland, Canada) has been studying burrowing mechanisms in pholadid pelecypods, in particular Penitella. He has recent publications on the relationship of rock hardness to burrow shape, identification of fossil burrows, and a method for estimating rock hardness at time of burrowing. Ciarence A. Hatt, Jr. (University of California, Los Angeles, California 90024)) is studying the late Miocene and Pliocene paleoecology of western San Luis Obispo County, California. THE VELIGER Page 137 Joun P Kern (San Diego State College, San Diego, California 92115) has a manuscript in press on the early Pliocene molluscan paleoecology of the eastern part of the Ventura basin, southern California, based on a recently completed doctoral thesis at the University of California, Los Angeles. Rosert G. McWituiaMs (Miami University, Oxford, Ohio 45056) is preparing a report on the paleoecology of late Eocene mollusks and corals from near Seattle, Washington. V. StanpisH Mattory (University of Washington, Seattle, Wash- ington 98105), in cooperation with gcomorphologist Donatp J. EasTERBROOK (Western Washington College, Bellingham, Washing- ton 98225), is studying the paleoecology of late Pleistocene and Holocene marine mollusks from glacio-marine tills in northwestern Washington. Louis MarincovicH expects to complete in mid-1969 a master’s thesis at the University of Southern California (Los Angeles, Cali- fornia 90007) on Pleistocene molluscan faunas of the higher marine terraces at Palos Verdes Hills, southern California. To date, 42 previously unreported species have been found in the higher terraces, many from new localities exposed during the continuing urbanization of the area. W. H. Easton of the same institution is collaborating with isotope geologist Joun K. Osmonp (Florida State University, Tallahassee, Florida 32306) on a study of radio- metric ages of molluscan faunas from these terraces. MARINCOVICH is also working on the paleoecology of the early Pleistocene Lomita Marl based on quantitative study of 119 species of mollusks. Rosert FE Meape (California State College at Los Angeles, Los Angeles, California 90032) has completed a doctoral thesis at the University of California, Los Angeles, on the paleoecology of the Santa Barbara zone of southern California. He has published pre- liminary reports on the shallow water Pliocene mollusks that have been incorporated in deep water turbidites of the Fernando Forma- tion. Gary RosENBERG has started a graduate research program at the University of California (Los Angeles, California 90024) on the paleoecology, distribution, and evolution of the bivalve mollusk Chione in California. Rosert W. Rowtanp has begun work on a doctoral dissertation at the University of California (Davis, California 95616) on Pleisto- cene mollusks of the Bering Sea. The study is being carried out in cooperation with Pleistocene geomorphologist Davin M. Hopxins (U.S. Geological Survey, Menlo Park, California 94025). Row- LAND recently completed a manuscript from his master’s thesis on the paleoecology of the molluscan fauna of the San Diego Forma- tion of northwestern Baja California, Mexico. Rosert J. STANTON, Jr. (Texas A&M University, College Station, Texas 77843) has completed a paleoenvironmental study of Mio- cene mollusks of the Temblor and Santa Margarita Formations from the western side of the San Joaquin Basin near Coalinga, Califor- nia. He has recent publications on the paleoecology of the upper Miocene Castaic Formation of the eastern portion of the Ventura basin, southern California. Rosert R. TaLMancE (2850 Pine Street, Eureka, California 95501) is studying the relationship of deep water mollusks from the Plio- cene Rio Dell Formation of the Wildcat Group, northern Califor- nia, to modern assemblages dredged off the nearby coast by trawlers. Page 138 THE VELIGER Vol. 12; No. 1 James W. VaLentTiNE (University of California, Davis, California 95616) is spending the 1968-1969 academic year on sabbatical leave at Oxford University, England, where he is writing a book on evolutionary paleoecology. Joun E. Warme (Rice University, Houston, Texas 77001) com- pleted a Ph. D. thesis at the University of California, Los Angeles, on paleoecologic aspects of the modern ecology of Mugu Lagoon, Ventura County, California. A recent publication concerning post- mortem transport in fossil assemblages was developed from the dissertation. BIOGEOGRAPHY Warren O. Appicott (U.S. Geological Survey, Menlo Park, Cali- fornia 94025) has recently published reports on Oligocene and Miocene zoogeographic discontinuities across the San Andreas fault, California, supporting inferences of post-Oligocene cumulative right-lateral slip of as much as 190 miles. He is currently completing studies on Miocene latitudinal faunal gradients along the Pacific coast and their relation to the San Andreas fault. A recent publication by J. Wyatr DurHam (University of Cali- fornia. Berkeley, California 94720) and FE Srearns MacNeEiIL (5958 Prather Drive, Fort Myers, Florida 33901) summarizes mol- luscan evidence for late Cenozoic marine migrations through Bering Strait beginning in the late Miocene. More than 125 species of Pacific origin have entered the Arctic-Atlantic area, whereas only about 16 Pacific species seem to have had Atlantic origins. A. Myra Keren (Stanford University, Stanford, California 94305) is continuing her long range study of the relation of California Miocene molluscan faunas to mollusks of the modern Panamic mol- luscan province of Central America. She has begun preparations for a revision of her important 1958 monograph on tropical mol- lusks of the eastern Pacific in cooperation with JupirH S. Terry. KATHERINE V. W. PaLMER (Paleontological Research Institution, Ithaca, New York 14850) reviewed Tethyan affinities of marine Eocene mollusks of North America, including the warm water Venericardia planicosta and Velates perversus groups, in a recent publication. James W. VALENTINE (University of California, Davis, California 95616) has recent publications on the evolution of marine mollus- can provinces and the climatic regulation of speciation. In coop- eration with CLarENcE A. HALL, Jr. (University of California, Los Angeles, California 90024), he is making a cluster analysis of late Miocene molluscan assemblages from California as a means of defining Tertiary molluscan provinces of the Pacific coast. PALEOCLIMATOLOGY Warren O. Appicotr (U.S. Geological Survey, Menlo Park, Cali- fornia 94025) is studying middle and late Tertiary climatic change in the nearshore marine environment through a distributional analy- sis of warm water molluscan genera. He has completed a manu- script on climatic change in the marginal eastern Pacific and is working on a detailed study of Tertiary paleoclimates of the San Joaquin basin, California. Crarence A. Hatt, Jr. (University of California, Los Angeles, California 90024) is studying growth layering in bivalved mollusks as an aid in paleobiogeographic interpretation of eastern Pacific molluscan faunas. Rosert J. Stanton, Jr. (Texas A&M University, College Station, Texas 77843) is working on a faunal and geochemical analysis of Pliocene marine climate of the northwestern San Joaquin basin, California, in cooperation with J. Rosert Dopp (Indiana Univer- sity, Bloomington, Indiana 47401). A preliminary report is in press. SYMPOSIA Plans for a symposium volume on molluscan biogeography of the eastern Pacific are being formulated by Victor A. ZULLO (California Academy of Sciences, San Francisco, California 94118) and Eucene V. Coan (Stanford University, Stanford, California 94305) . Several molluscan paleontologists will be invited to contrib- ute to this effort. Davin M. Hopkins’ (U.S. Geological Survey, Menlo Park, Cali- fornia 94025) recently published symposium on the Bering Land Bridge (1967) includes several papers containing Tertiary and Quaternary molluscan faunal data from Alaska and Chukotka, in- cluding a report by J. Wyatt DurHaAM and F Stearns MacNem on Cenozoic migrations through Bering Strait. Dwicut W. Taytor (Arizona State University, Tempe, Arizona 85281) is editing a review volume on malacology in western Amer- ica. Contributions by molluscan paleontologists on marine ecology and taxonomy are planned. CATALOGS, GUIDEBOOKS Warren O. Appicotr (U.S. Geological Survey, Menlo Park, Cali- fornia 94025) is preparing annotated bibliographies of literature on Neogene and Quaternary mollusks of the eastern Pacific Ocean and arctic Alaska. James H. McLean (Los Angeles County Museum of Natural History, Los Angeles, California 90007) has completed a catalog of living marine mollusks of Los Angeles County coast, California, and is working on a distributional list of modern prosobranch gastro- pods of the northeastern Pacific from Alaska to central Baja Cali- fornia. ELLEN J. Moore (San Diego Museum of Natural History, San Diego, California 92112) recently completed a guidebook of fossil mollusks of San Diego County, California, with illustrations of Eocene, Pliocene, and Pleistocene species. RADIOMETRIC AGE DETERMINATIONS Several isotope geologists are working in cooperation with paleon- tologists and biostratigraphers in attempting to provide radiometric age control for Cenozoic stratigraphic sections along the Pacific coast. Vol. 12; No. 1 THE VELIGER Page 139 Late Pleistocene and Holocene radiocarbon ages based upon marine mollusks' shells have been reported by many workers during the past 10 years or so. These have been particularly useful in determining Holocene events in northwestern Washington and south- western British Columbia, Canada. In the past three years, uranium-series disequilibrium methods of dating mollusk.shells have become increasingly useful in deciphering late Pleistocene history of the Pacific coast during the past 200 000 years. H. HerBertT VEEH (Yale University, New Haven, Connecti- cut 06511) and James W. VALENTINE (University of California, Davis, California 95616), BARNEY J. Szaso and Joun N. RosHoLtT (U.S. Geological Survey, Denver, Colorado 80225), Wittiam C. BrapLey (University of Colorado, Boulder, Colorado 80302) and Warren O. Appicotr (U.S. Geological Survey, Menlo Park, Cali- fornia 94025), Horace G. Ricuarps (Academy of Natural Sciences, Philadelphia, Pennsylvania 19103), and Dav L. TuurBer (La- mont Geological Laboratory, Palisades, New York 10964), FE P. FanaLe and O.A.ScHaArFFeR (Brookhaven National Laboratory, Upton, New York 11973) have published papers during the past three years dealing with the radiometric ages of Pleistocene terrace faunas from California and southwestern Oregon. Potassium-argon dating of Tertiary volcanic rocks and glaucon- ites relevant to molluscan correlation is being carried out by JoHN D. OxsrapovicH and by Donatp L. Turner, both of the U.S. Geological Survey (Denver, Colorado 80225). OsrapovicH has been dealing with Pliocene and Pleistocene ages as related to the Pacific coast marine chronologies; TuRNER recently completed a doctoral dissertation at the University of California, Berkeley, on K-Ar dates concerning the Miocene foraminiferal chronology and has a paper in press summarizing these data. He is planning to extend his work, in collaboration with Warren O. AppicotT, to include radiometric calibration of the Pacific coast molluscan sequence. ISOTOPIC STUDIES J. Rosert Dopp (Indiana University, Bloomington, Indiana 47401) has completed a study of oxygen isotope and strontium paleotem- perates of Pliocene and Pleistocene Mytilus from California. He has undertaken a joint study with Ropert J. Stanton, Jr. (Texas A&M University, College Station, Texas 77843) of oxygen isotopic temperatures of Pliocene mollusks from the Kettleman Hill area central California. 2 Cart L. Husss (Scripps Institution of Oceanography, La Jolla, California 92037) is studying paleoclimatological aspects of a mixed tropical and warm temperate late Pleistocene molluscan fauna from Guadalupe Island, Mexico, by means of oxygen isotope determina- tions. Epwarp C. Wirson (Los Angeles County Museum of Natural History, Los Angeles, California 90007) has been studying the paleo- ecology of this mixed fauna. Heinz A. Lowenstam (California Institute of Technology, Pasa- dena, California 91109) continues his oxygen isotope paleotem- perature studies on Tertiary invertebrates. OTHER STUDIES J. Rosert Dopp (Indiana University, Bloomington, Indiana 47401) has recently published a report on the relation of skeletal structure and shell mineralogy to growth temperature and salinity based on Pleistocene specimens of Mytilus from northwestern Baja California and California. GeorceE R. Crark II is completing a Ph. D. dissertation at Califor- nia Institute of Technology (Pasadena, California 91109) on daily growth increments in the Pectinidae. His work includes paleoeco- logic applications in the study of late Tertiary pectinids from Baja California. H. Epwarp Cuirton (U.S. Geological Survey, Menlo Park, Cali- fornia 94025), a sedimentologist, has been investigating the pre- ferred orientation of disarticulated valves of late Cenozoic pelecy- pods, particularly Psephidia, in the shallow water Elk River Forma- tion of southwestern Oregon. In addition to field observation, Cuirton has been introducing fossil shells into modern subtidal environment and monitoring settling patterns by use of self-con- tained underwater breathing apparatus. Similar studies, including laboratory experimentation, have been made by Cortez W. Hos- KINS (Union Oil Company Research Laboratory, Brea, California 92621) on a small, undetermined pelecypod that occurs abundantly in deep water Pliocene turbidites in the Ventura basin, southern California. Page 140 THE VELIGER Vol. 12; No. 1 THE CairorniA MALACOZOOLOGICAL Society, Inc. announces Backnumbers of THE VELIGER and other publications Volumes 1 through 8: out of print Volume 9: $22.- Volume 10: $24.- Volume 11: $24.- Supplement to Volume 3: $6.-* plus $-.50 handling charge [Part 1: Opisthobranch Mollusks of California by Prof. Ernst Marcus; Part 2: The Anaspidea of California by Prof.. R. Beeman and The Thecosomata and Gymnosomata of the Cali- fornia Current by Prof. John A. McGowan] [The two parts are available separately at $3.- each plus a handling charge of $-.40 or as indicated above. If purchased separately, each part is subject to the Califor- nia State sales tax if mailed to California addresses. | Supplement to Volume 7: $2.-* plus $-.40 handling charge [Glossary of A Thousand-and-One Terms used in Conchology, compiled by Wintrrep H. Arno.p] Supplement to Volume 11: $5.-* plus $-.40 handling charge [The Biology of Acmaea by Prof. D. P. Assortt et al., ed.] Items marked with * are subject to sales tax in the State of California; residents of that State please add the appropriate amount to their remittances. Prices subject to change without notice. Send orders with remittance to: Mrs. Jean M. Cate, Manager, 12719 San Vicente Boule- vard, Los Angeles, Calif. 90049. Please, make checks payable to C. M.S., Inc. Shipments of material ordered are generally made within two weeks after receipt of remittance. Subscription to Volume 12: $18.- domestic; $19.- in Canada, Mexico, Central and South America; $19.50 in all other foreign countries. Backnumbers of the current volume will be mailed to new subscribers, as well as to those who renew late, on the first working day of the month following receipt of the remittance. The same policy applies to new members. Affiliate Membership for the fiscal year July 1, 1969 to June 30, 1970 has been set at $8.-. Postage for members in Canada, Mexico, Central and South America $1.-, for members in any other foreign country $1.50 additional. Membership open to individuals only - no institutional or society memberships. Please send for membership ap- plication forms to the Manager or the Editor. At a Regular Membership Meeting of the CALiForNIA MatacozootocicaL Society, Inc. the following policies were adopted by unanimous vote: Effective January 1, 1967 there will be an initiation fee of $2.- for persons joining the Society. NOTE: No Insti- tutional Memberships are possible in the C. M.S., Inc. Members receive The Veliger free of further charges and are entitled to purchase one copy of any supplement pub- lished during the current membership year at a special discount (to be determined for each supplement). Membership renewals are due on or before April 15 each year. If renewal payments are made after April 15 but before March 15 of the following year, there will be a re-instatement fee of $1.-. Members whose dues pay- ments (including the re-instatement fee) have not been received by the latter date, will be dropped from the rolls of the Society. They may rejoin by paying a new initiation fee. The volume(s) published during the time a member was in arrears may be purchased, if still available, at the regular full volume price plus applicable handling charges. Manuscripts received up to February 14 each year will be considered for publication in our July issue; May 14 is the deadline for the October issue, August 14 for the January issue and November 14 for the April issue. For very short papers of less than 500 words (including title, etc.) the deadlines are one month later than those given above, provided that these short notes are impor- tant enough to warrant preferential treatment. It is, how- ever, understood that submission of a manuscript before the dates indicated is not a guarantee of acceptance. ABOUT SUPPLEMENTS Many of our members desire to receive all supplements published by the Society. Since heretofore we have sent supplements only on separate order, some members have missed the chance of obtaining their copy through over- sight or because of absence from home. It has been sug- gested to us that we should accept “standing orders” from individuals to include all supplements published in the future. After careful consideration we have agreed to the proposal. We will accept written requests from individuals to place their names on our list to receive all future sup- plements upon publication; we will enclose our invoice at the same time. The members’s obligation will be only to pay promptly upon receipt of the invoice. Vol. 12; No. 1 THE VELIGER Page 141 Requests to be placed on this special mailing list should be sent to the Manager, Mrs. Jean M. Cate, 12719 San Vicente Boulevard, Los Angeles, California 90049. Correction! Due to an unfortunate error, the names of the shells illustrated in Figures 3 and 5, Plate 56, in our volume 11, were transposed. The species illustrated in Figure 3 is Volva birostris (LinNAEuS, 1758) while that in Figure 5 is Volva brevirostris (SCHUMACHER, 1817). Your Editor regrets the mixup and tenders his apologies. Moving? 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Endowment Fund At a Regular Membership meeting of the Society in No- vember 1968 a policy was adopted which, it is hoped, will assist in building up the Endowment Fund of the Society. An issue of the journal will be designated as a Memorial Issue in honor of a person from whose estate the sum of $5000.- or more has been paid to the Veliger Endowment Fund. If the bequest is $25 000.- or more, an entire volume will be dedicated to the memory of the decedent. In the face of continuous rises in the costs of printing and labor, the income from the Endowment Fund would materially aid in avoiding the need for repeated upward adjustments of the membership dues of the Society. It is the stated aim of the Society to disseminate new infor- mation in the field of malacology and conchology as widely as possible at the lowest cost possible. CALIFORNIA MALACOZOOLOGICAL Society, Inc. is a non-profit educational corporation (Articles of In- corporation No. 463389 were filed January 6, 1964 in the office of the Secretary of State). The Society publishes a scientific quarterly, the VELIGER. Donations to the Society are used to pay a part of the production costs and thus to keep the subscription rate at a minimum. Donors may designate the Fund to which their contribution is to be credited: Operating Fund (available for current production) ; Savings Fund (available only for specified purposes, such as publication of especially long and signi- ficant papers); Endowment Fund (the income from which is available. The principal is irrevocably dedicated to scientific and educational purposes). Unassigned dona- tions will be used according to greatest need. Contributions to the C. M.S., Inc. are deductible by donors as provided in section 170 of the Internal Revenue Code (for Federal income tax purposes). Bequests, lega- cies, gifts, devices are deductible for Federal estate and gift tax purposes under section 2055, 2106, and 2522 of the Code. The Treasurer of the C. M. S., Inc. will issue suitable receipts which may be used by Donors to substan- tiate their respective tax deductions. We regret that, due to circumstances beyond our control, we are unable to include our reviews of Books, PERIODICALS & PAMPHLETS in this issue. Page 142 METHODS & TECHNIQUES A Simplified Vacuum Apparatus for Collecting Small Nudibranchs BY J. SHERMAN BLEAKNEY Department of Biology, Acadia University Wolfville, Nova Scotia (1 Text figure) IF YoU HAVE EXPERIENCED the exasperation of collecting small aquatic organisms with a combination of forceps, eye dropper, screw-top jar, snap-lid vial, strainer and dip net, then you will appreciate the simplicity of the appa- ratus detailed in Figure 1. When a rubber sheet is attached over the open end of the cylinder, finger pressure on the rubber will displace air out of the tube at the side. If this spout is placed in water in the proximity of a small specimen and the pressure on the rubber released, the specimen will disappear from its habitat and reappear ay ™~ ik 3/32” / 5/16” | 1/16” Ome 54” Drill Thickness - 1/16” : ; Length - 134” Plexiglass Tubing O.D.-34” Thickness - 44” Length - 114” THE VELIGER Glue Line Plexiglass EA ” x1 / 1 6” ~ Vol. 12; No. 1 instantaneously in the cylinder. The specimen can be examined with a hand lens as it swims, crawls or attaches itself within the transparent cage. Additional specimens can be collected in the same cylinder as rapidly as your finger can slowly depress and quickly release the elastic cover of the container. This is a one-hand-only operation: holding the cylinder and depressing the top with the index finger. In cold water, neoprene diver’s gloves can be worn without interfering with the efficiency of the technique. Specimens can be transported to the laboratory in the cylinder and stored in a refrigerator until examined under a binocular microscope after removal of the rubber sheet. Thus specimens quite literally need never be handled by fingers or forceps during capture, transport, storage or examination — not until they are removed for more de- tailed examination or preservation. For this reason the apparatus has been termed a Single Operation Collecting Kit, abbreviated to SOCK, and respectfully designated an “Acadian SOCK” in deference to an institution that has fostered many a field biologist. Some of the design presented in Figure 1 is rather refined. The shut-off valve in the spout is not really necessary because a vacuum effect limits the loss of water. It is basically to keep specimens from escaping, but they rarely find the opening, especially if the water LD. 114” O.D. 134” | | 3/16” | Rounded Edges 1/16” Cut - 1%” Wide ~<— Plexiglass Tubing O. D. 134” Thickness - 14” Length - 334” ~ =<— Plexiglass 1 ¥f," x 4” Vol. 12; No. 1 THE VELIGER Page 143 level is kept below the level of the spout. To lower the water level in a SOCK, the diaphragm can be pumped with the index finger and jets of water will be ejected from the spout and no specimens, if they are crawling mollusks. This apparatus was made specifically for col- lecting sacoglossan and nudibranch mollusks in the size ranges of < 2.5 cm. The O-ring and medium gauge den- tal latex can easily be substituted by a string and a piece of toy balloon or rubber glove. If you keep a few “Acadian SOCKs” in your car, then a complete collecting kit for sea shore or lake is always at hand and the expendable parts can be purchased or replaced afresh in the shopping center of even the smallest town. My tide pool technique was to carry a basket loaded with 10 Acadian SOCKs. Each species of nudibranch collected was kept in a separate SOCK. If occasional nudibranchs were too large or some of the dorids too stiff then the rubber was flipped off and the specimen dropped in with the others and the diaphragm replaced. Specimens to be collected must be submerged, but it does not matter if the SOCK has air or water or both in it. The SOCK can be partly in air and water or totally sub- merged. Specimens were scraped off the underside of overturned rocks with the SOCK spout (or forceps) and positioned in the aperture of the spout. The diaphragm was depressed and the spout submerged in the nearest pool of water, releasing the finger pressure at the same time. The mucoid blob from the rock surface, now sub- merged in sea water in the SOCK, would then assume its natural shape and was examined with a hand lens. The principle employed in the Acadian SOCK appara- tus is applicable to larger and smaller diameter spouts and cylinders. As long as the volume displaced by depres- sing the rubber lid is greater than that of the spout, then any small or delicate organism can be drawn back into the cylinder within a gentle stream of water. I have field-tested two sizes of SOCK apparatus in 7 countries since January 1968 and can attest to their effectiveness. In fact, I have had the pleasure of using SOCK apparatus with SCUBA gear in Zostera beds and in algal jungles. One need only shake specimens off the plants or epizoans and then leisurely “pick them out of the air” as they drift about; or pieces of plants or hydroids or polyzoans with attached nidosomes and adult nudibranchs can be broken off and sucked up together. The uninterrupted hours necessary to evolve the design of the Acadian SOCK were made possible by a year of Sabbatical leave from Acadia University, and a Canadian National Research Council Senior Research Fellowship. The author is further indebted to Professor George Hughes, Chairman, Department of Zoology, Bristol University, England, for providing workshop facilities where the pro- totypes and present model were constructed. Technique for Extraction and Mounting of Gastropod Radulae BY GEORGE E. RADWIN Curator of Marine Invertebrates San Diego Natural History Museum San Diego, California 92112 I HAVE USED the following procedure for extracting and mounting radulae for a number of years. It is largely a pragmatic technique developed by a process of trial and error. The extraction procedure differs depending on the size and condition of the specimen from which the radula is to be extracted. If a dried specimen is to be used, it should be boiled in a saturated solution of trisodium phos- phate (TSP). If the animal has dried deeply retracted into the shell such boiling in TSP will usually cause sof- tening and swelling sufficient to allow it to be seen and removed from the shell. If the specimen is small, the entire animal is usually treated. If a large animal is used, the first step must be to remove the buccal mass, lying immediately behind the foot and head areas and just below the mantle cavity. The softened animal (or the buccal mass) is then boiled in a concentrated solution of sodium hydroxide for a short time(3- 10 seconds), re- ducing it to a viscous brown film on the surface of the NaOH solution. This brown scum is removed by pipette and transferred to a watch glass with 70% ethanol. Gently swirling the watch-glass, while carefully viewing it under a dissection microscope will generally cause the brown film to dissipate and leave the radula as a highly refractive filamentous object. The radula is generally a ribbon-like structure which may be removed by the aid of needles, and stored in a vial of alcohol. If the radula of a toxoglossate species [Conidae, Terebridae, Turridae] is extracted, the radula may be a packet of tiny “darts.” The radula under microscopic scrutiny is transferred to a depression slide containing a drop of eosin stain and allowed to remain there until the drop has dried. Using a disposable hypodermic syringe the depression slide is carefully filled with 70% ethanol. When the radula has been sufficiently destained (5-10 minutes), the 70% ethanol is removed, using the hypodermic syringe, and re- placed with 95% ethanol. The lightly stained radula is allowed to remain in the 95% ethanol for about 5 minutes, then transferred with needles to a slide with a drop of xylene or water-based mounting medium. Still viewing the radula under the dissection microscope, a small section of the radula is removed intact and segregated, the remainder Page 144 THE VELIGER of the radula being dissociated with a pair of very finely ground needles. This step precludes confusion due to overlapping teeth. If xylene is used, the radular material is covered with a drop or more of canada balsam moun- ting medium. If a water-based mounting medium is used, the step involving xylene must be omitted and the radular material is transferred directly from 95% ethanol to the mounting medium, and covered with a cover slip. The prepared slide may be viewed after 2 or 3 days, by which time the radular teeth have stopped rotating. For best results a compound microscope capable of a magnification of at least 400 x should be used. MATERIALS NEEDED . saturated solution of trisodium phosphate . concentrated solution of sodium hydroxide . alcohol lamp, ringstand, ring and wire mesh . 3 disposable hypodermic syringes . 2very finely ground wooden-handled dissecting needles . 70% ethanol . 95% ethanol . xylene . canada balsam or other permanent mounting medium 10. eosin or eosin-type stain 11. 3 depression slides 12. 1 watch glass ( 1 - 2 inches in diameter) 13. 2 microscopes (1 dissection, 1 compound) 14. microscope slides and coverslips ODUM TPwWDH we Vol. 12; No. 1 THE VELIGER is open to original papers pertaining to any problem concerned with mollusks. This is meant to make facilities available for publication of original articles from a wide field of endeavor. Papers dealing with anatomical, cytological, distri- butional, ecological, histological, morphological, physiological, taxonomic, etc., aspects of marine, freshwater or terrestrial mollusks from any region, will be considered. Even topics only indirectly concerned with mollusks may be acceptable. It is the editorial policy to preserve the individualistic writing style of the author; therefore any editorial changes in a manuscript will be submitted to the author for his approval, before going to press. Short articles containing descriptions of new species or other taxa will be given preferential treatment in the speed of publication provided that arrangements have been made by the author for depositing the holotype with a recognized public Museum. Museum numbers of the type specimens must be included in the manuscript. Type localities must be defined as accurately as possible, with geo- graphical longitudes and latitudes added. Short original papers, not exceeding 500 words, may be published in the column “NOTES and NEWS’; in this column will also appear notices of meetings of regional, national and international malacological organizations, such as A. M. U., U.M.E., W.S.M., etc., as well as news items which are deemed of interest to our Members and subscribers in general. Articles on “METHODS and TECH- NIQUES” will be considered for publication in another column, provided that the information is complete and techniques and methods are capable of duplication by anyone carefully following the description given. Such articles should be mainly original and deal with collecting, preparing, maintaining, studying, photographing, etc., of mollusks or other invertebrates. A third column, entitled “INFORMA- TION DESK,” will contain articles dealing with any problem pertaining to collecting, identifying, etc., in short, problems encountered by our readers. In contrast to other contributions, articles in this column do not necessarily contain new and original materials. Questions to the editor, which can be answered in this column, are invited. The column “BOOKS, PERIODICALS, and PAMPHLETS” will attempt to bring reviews of new publications to the attention of our readers. Also, new timely articles may be listed by title only, if this is deemed expedient. Manuscripts should be typed in final form on a high grade white paper, not exceeding 81,” by 11”, at least double spaced and accompanied by a clear carbon or photo copy. A pamphlet with detailed suggestions for preparing manuscripts intended for publication in THE VELIGER is available to authors upon request. A self-addressed envelope, sufficiently large to accommodate the pamphlet (which measures 51,” by 8%”), with double first class postage, should be sent with the request to the Editor. EDITORIAL BOARD Dr. Donatp P. Axszort, Professor of Biology Hopkins Marine Station of Stanford University Dr. Jerry DononveE, Professor of Chemistry University of Pennsylvania, Philadelphia, and Research Associate in the Allan Hancock Foundation University of Southern California, Los Angeles Dr. J. Wyatt Duruam, Professor of Paleontology University of California, Berkeley Dr. E. W. Facer, Professor of Biology Scripps Institution of Oceanography, La Jolla University of California at San Diego Dr. Caner Hann, Professor of Zoology and Director, Bodega Marine Laboratory : University of California, Berkeley Dr. G Datias Hanna, Curator Department of Geology California Academy of Sciences, San Francisco Dr. Jorn W. Hepcretu, Resident Director Marine Science Laboratory, Oregon State University Newport, Oregon Dr. Leo G. HERTLEIN, Curator of Invertebrate Paleontology California Academy of Sciences, San Francisco EDITOR-IN-CHIEF Dr. RupotF STouieR, Research Zoologist University of California, Berkeley : Scripps Institution of Oceanography, La Jolla Dr. A. Myra KEEN, Professor of Paleontology and Curator of Malacology Stanford University, Stanford, California Dr. Victor LoosanorrF, Professor of Marine Biology Pacific Marine Station of the University of the Pacific Dr: -“Joun McGowan, Associate Professor of Oceanography University. of California At. San Pies. Dr. FRANK A. Pare praia af Yasloay University of California; Berkeley Mr. ALLyn G. Suir, Associate Giirator Department of Invertebrate Zoology California Academy of Sciences, San Francisco Dr. Raupu I. Smiru, Professor of Zoology University of California, Berkeley Dr. Cuarzes R. Stasex, Associate Professor of Zoology Florida State University, Tallahassee, Florida Dr. Donatp M. Wixson, Professor of Biology Department of Biological Sciences Stanford University, Stanford, California ASSOCIATE EDITOR Mrs. JEAN M. Cate Los Angeles, California S597¢,05 4.3 Astl. THE VELIGER A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, INC. Berkeley, California VOLUME 12 October 1, 1969 NuMBER 2 ContTENTS Remarks on the Taxonomic Placement of Purpurellus JoussEAUME, 1880, with the Description of a New Species (Gastropoda: Muricinae). (Plates 26, 27; 2 Text figures) Witrmm K Emerson-« Antuony DiArmmio . . .. =... =.=... . 145 Two New Species of Galapagan Turrid Gastropods. (Plates 28, 29; 5 Text figures) Wirram K> Emerson & Grorce EF. RapwiIN . ..... =... =. = - 149 Escape Responses of Three Indian Molluscs. END) VANSELL ees SA esc, Semon C7) Identification of the Beeding Ty pen in ate Genus Conus Iwacuet (Plate 30; 5 Text figures; 2 Tables) C. EF Lim Bele : Ae ficwece yar TOO Panamic Sites and rehveslowical roitesrs ae Dower Galicomiat (2 Tables) LawreNcE H. FELDMAN. . . Bie) OS Cyclostrema miranda BartscH, a Si ronyin GE Tatas hibcatinaeus (ioneden): (3 Text figures) Donatp R. Moore. . . . 169 Relative Growth Patterns of Two West Coast Squid ( Génatn fabric and Gonate ne borealis). (2 Text figures) Larry T. SPENCER . . . ely i Occurrence of the Sacoglossan @pithonranch H ermaea dendntce fioents Hancore in New England. Kerry B. Crark & Davip R. FRANz . Soin dane aig Observations on the Tentacles of Vaginulus boreliianus Covent (Mollusca: Gastro- poda: Soleolifera) . (Plates 31 to 35; 3 Tables) ARISTEO RENZONI . . Sh aon Loe rue ieee TO Marine Fouling and Boring @reanignsn in Monterey Harbor — II. Second Year of Investigation. (2 Text figures; 2 Tables) Ei CBLUADERTIE Maan nist oc aut tly ec. MRO ache coe wie tte ase) ois ve va VOR [Continued on Inside Front Cover] Distributed free to Members of the California Malacozoological Society, Inc. Subscriptions (by Volume only) payable in advance to Calif. Malacozool. Soc., Inc. Volume 12: $18. Domestic; $19.- in the Americas; 19.50 in all other Foreign Countries Single copies this issue $9.00. Postage extra. Send subscription orders to Mrs. JEAN M. CaTE, 12719 San Vicente Boulevard, Los Angeles, California 90049. Address all other correspondence to Dr. R. STOHLER, Editor, Department of Zoology, University of California, Berkeley, California 94720 Second Class Postage paid at Berkeley, California VOM ax I ContENTs — Continued Population Characteristics of Protothaca staminea (ConrapD) from Mugu Lagoon, California. (9 Text figures) Ronatp R. Scumipt & Joun E. WARME , . . Simeon Mimicry of the Gastropod Mitrella carinata by the onpiipod Pleustes platypa. (Plate 36) Juves M. Crang, Jr. . . 200 Cypraeidae of the Red Sea at Maudie Eaiopia) nth a ‘Zooyeographical rAralyat’ based on the Scuitpers’ Regional Lists. (2 Text figures; 1 Map) T.C. Fore L.P Russusn . . . . 201 The Distribution and Ecology of Sub- itera Species Gf Macoms (Bivalvia) off Moresby Island and in Satellite Channel, near Victoria, British Columbia. (9 Text figures; 3 Tables) R. M. Dunnuit « D. V. Evttis . . . 207 Additional Bathymetric and Locality Data fone some lOnmthobranci nadl¢ an crept from Santa Barbara County, California. » . 193 Ricwarp S. Lez « Patrick BRoPpHY .. . BGS 6 CRO A Bibliography of the Biological Writings of Eanes iSaomeann Gieeenmee! EUGENE V. GOAN Gitte 0 os Ny ak ie eG Vetere CRP oe ten gles0 ke ten Mato 2 2.2 NOTES & NEWS (oii. ce05) ie) a inte 28) Se gout iste conus eo atirck ante) On RP oa 2 Russian Contributions to Malacology. KENNETH J. Boss Report on some Abnormal Chitons from California and British Columbia. GLENN BurcHarpT & Laura BURGHARDT New Range for Mopalia hindsi recurvans BARNAWELL, 1960. GLENN BurcHarRDT & LauRA BURGHARDT Range Extension of Tylodina fungina in the Gulf of California. James W. McBetu « R. Davin Bow.Lus Ascophyllum nodosum: A Source of Exotic Invertebrates Introduced into West Coast Near-Shore Marine Waters. RicHarp L. MILLER Cadlina modesta: A Range Extension, with Notes on Habitat and a Color Variation. (1 Text figure) Hans BertscH A Note on the Opisthobranchs of Santa Cruz Island, California. STEVEN J. Lonc BOOKS, PERIODICALS & PAMPHLETS. .......... .. . 234 Note: The various taxa above species are indicated by the use of different type styles as shown by the following examples, and by increasing indentation. ORDER, Suborder, DIVISION, Subdivision, SECTION, SUPERFAMILY, Famity, Subfamily, Genus, (Subgenus) New Taxa Vol. 12; No. 2 THE VELIGER Page 145 Remarks on the Taxonomic Placement of Purpurellus JOussEAUME, 1880, with the Description of a New Species (Gastropoda : Muricinae) WILLIAM K. EMERSON AND ANTHONY D’ATTILIO Department of Living Invertebrates, American Museum of Natural History Seventy-ninth Street and Central Park West, New York, New York 10024 (Plates 26 and 27; 2 Text figures) AMONG THE MOLLUSKS obtained by the “Ariel Expedi- tion” to western Mexico in 1960 is a remarkable new species of muricid gastropod. A single specimen was sorted from a trawling sample obtained in the Gulf of California by Dr. G. Bruce Campbell of Lynwood, California. Dr. Campbell has kindly permitted us to describe it and he generously deposited the holotype in the Los Angeles County Museum of Natural History. A second specimen, dredged in the Bay of Panama in 1935, was subsequently found in the vast molluscan collections of the Allan Han- cock Foundation. The gastropods of this collection have been deposited on loan to the Los Angeles County Muse- um of Natural History by the University of Southern Cali- fornia. These specimens, both lacking soft parts, form the basis for the description. We take pleasure in naming this interesting discovery in honor of Dr. James H. McLean, Curator of Mollusks, Los Angeles County Museum of Natural History, who recog- nized it in the Hancock Collection. As a result of the present study, we have presented anatomical evidence that requires the placement of Pur- purellus JouSSEAUME, 1880, in the muricacid subfamily Muricinae. Accordingly, we have re-assigned Purpurellus from the Ocenebrinae to the status of a subgenus in the muricid genus Pterynotus Swanson, 1833 (sensu lato). MuRIGACEA MourIciAgE Muricinae Pterynotus Swainson, 1833 Pterynotus Swainson, 1833, explanation to plate 100, type species: Murex pinnatus Swainson, 1822 [= Purpura alata Ropinc, 1798], by SD, Swarnson, 1833, explanation to plate 122. Voxes, 1964, plt. 14, plt. 37, figs. 24 (shell), 51 (radula), 63 (operculum) of Purpura alata. Remarks: This genus has been traditionally placed in the subfamily Muricinae owing to the presence of a typically muricid shell and a muricoid operculum with a basal nucleus. As pointed out by Voxes (1964, p. 15), the rad- ular central tooth of the type species, Purpura alata, dif- fers from that commonly found in the Muricinae in having lost the smaller mtermediate cusps of the central tooth. This condition may reflect a specialized feeding adaptation. (Purpurellus) JoussEAUME, 1880 Purpurellus JouSSEAUME, 1880, p. 335, type species: Murex gambiensis REEVE, 1845, by OD. VoxEs, 1964, Page 146 p. 26, fig. 79 (shell of Murex gambiensis). Triremis “Bayle MS” FiscHer, 1884, p. 641, type species: Murex gambiensis Reeve, 1845, by OD. THIELE, 1929, p. 288, fig. 313 (radula of Murex gam- biensis). Remarks: Vokes (1964, p. 26) recently afforded Purpur- ellus JoUSSEAUME, 1880, subgeneric rank in the genus Pteropurpura JoUSSEAUME, 1880, of the subfamily Triton- aliinae [= Ocenebrinae]. This generic and subfamilial placement was prompted largely by the similarity of the shell morphology of the type species, Murex gambiensis Reeve, 1845, with that of Pteropurpura (s.s.). She dis- tinguished the shells of Purpurellus by their possession of a greatly widened siphonal canal and the extreme inter- ruption developed in the varical fringe between the body whorl and the siphonal canal. Voxes noted that THIELE’s (1929, p. 289) illustration of the radula of Murex gam- biensis depicts muricine dentition and thus would require placement of Purpurellus in the Muricinae, but she questioned the authenticity of the figure and relied on the apparent affinity of the shell morphology with that of Pteropurpura for subfamilial assignment. We have found, however, the radular dentition of Murex pinniger Broverip, 1833, an eastern Pacific repre- sentative of Purpurellus, to be muricine (Text figure 1) and to be reminiscent of THIELE’s radular figure of M. gambiensis (Text figure 2). Both species are now deter- Figure 1 Pterynotus (Purpurellus) pinniger (BRoveErIP, 1833) Rachidian and lateral dentition, approximately 300; specimen obtained by fishermen out of Guaymas, Sonora, Mexico; L. Thomas collection THE VELIGER Vol. 12; No. 2 mined to have muricine radulae, necessitating placement of Purpurellus in the subfamily Muricinae. We, therefore, have returned Purpurellus to the status of a subgenus in the genus Pterynotus (sensu lato), where it previously was assigned (Emerson, 1960). Figure 2 Pterynotus (Purpurellus) gambiensis (REEVE, 1845) Rachidian and lateral dentition, greatly enlarged {after THIELE, 1929, p. 289, fig. 313] The following Recent species are known to be referable to Purpurellus: 1. Murex gambiensis Reeve, 1845 [= ? Murex osseus REEVE, 1845], the type species, from the tropical eastern Atlantic. 2. Murex pinniger Broverip, 1833 [= Centrifuga inezana Duruam, 1950, fide SHaAsky & CAMPBELL, 1964, p. 116], from the tropical eastern Pacific. 3. Pterynotus (Purpurellus) macleani, spec. novy., described herein, from the tropical eastern Pacific. In addition to the three living species, extinct species of Purpurellus are known from the Early Miocene of North Carolina, the Miocene of France, and the Pliocene of Italy (VoKEs, in litt.). The available distributional data, therefore, indicate that the living representatives of this group are surviving, relict elements of the older Tertiary, west-Tethyan faunas. This would explain the present ap- parently discontinuous distribution, with species now living in the tropical eastern Atlantic and the eastern Pacific Oceans, but not occurring in the western Atlantic. The status of Centrifuga inezana DurHAM, 1950, pp. 113, 114, plt. 26, figs. 1, 4 (here illustrated, Plate 27, Explanation of Plate 26 Pterynotus (Purpurellus) macleani EMERSON & D’ATTILIO, spec. nov. Figures 1, 2: Holotype, Loreto Channel, Baja California, Mexico, in 25 fathoms; 2. (Note open siphonal canal and immature outer lip). Figures 3, 4: Paratype, off Secas Island, Panama, in 12 fathoms; 2. (Note closed siphonal canal and mature stage of apertural lip) . Pterynotus (Purpurellus) pinniger (BRODERIP, 1833) Figures 5, 6: Bicolored juvenile specimen of 5 postnuclear whorls, Santa Rosalia, Isla San Marcos, Baja Califomia, Mexico, Ben and Ruth Purdy collection; <2. Figure 7: Juvenile specimen of 6+ postnuclear whorls, Panama Bay, Panama, dredged, Lee and Helen Beils leg., ex- Ruth Craine collection; X2. © Nn o ~ as Qy (=) fe) + 4 o B 5 & a0 < i a) 3B a fe) w % [<3) = eh $2 oO =) 2) oo. = By aN oO + =) 0 o- By oO Hw =} aot ey Tue VELIGER, Vol. 12, No. 2 Figure 7 Figure 6 Figure 5 Wol 2 Now 2 THE VELIGER Page 147 Figures 1, 2) requires additional comment. On the basis of the limited data previously available (EMERSon, 1960, pp. 10-12, figs. 6, 7), we concluded that DurHAm’s taxon was referable to the subgenus Purpurellus, but we could not determine with certainty its conspecificity with Pterynotus(Purpurellus) pinniger (BRopERIP, 1833). VoKES (1964, p. 26) subsequently pointed out that the type localities of these taxa (Ecuador for pinniger and the Gulf of California for inezana) were geographically sep- arated by some 3000 miles. SHasky & CAMPBELL (1964, p. 116) reported on additional specimens and they con- cluded that the two nominal species were synonymous. One of Shasky’s specimens from the Guaymas area in the Gulf of California is illustrated herein (Plate 27, Figures 3, 5), and it can be assigned with confidence to P (P) pinniger, cf. Plate 27, Figures 5, 6. Although the holotype of Pterynotus (Purpurellus) inezana (DURHAM, 1950) is a poorly preserved (broken and water worn) Pleistocene specimen, the presence of P (P) pinniger in the Gulf of California serves to substantiate the findings of SHasky & CAMPBELL, and we have placed znezana in the synonymy of pinniger. Pterynotus (Purpurellus) macleant EMERSON & D’ATTILIO, spec. nov. (Plate 26, Figures 1 to 4) Diagnosis: A small muricid of 7 postnuclear whorls with broadly expanded varices. The shell is similar to that of Pterynotus (Purpurellus) pinniger, but the much smaller shell has a stouter appearance. Specimens of the new spe- cies with 7 postnuclear whorls are less than } the size of specimens of this congenitor with the same number of whorls. Description: Shell is small, translucent pink, polished, of thin and fragile appearance, with three wing-like varices; the 7 whorls blend into a protoconch of 14 convex whorls. Spire is slightly convex, with a well defined suture and on the later whorls has a tubercle-like bulge which be- comes reduced near the sutural groove. The body whorl is swollen in the area of the large tubercle at the shoulder. The three thin blade-like varices have a sinuous contour; they overlap from one whorl to the next forming, in part, on the spire, one continuous blade, demarked only by sutural indentations. On each whorl the varices, just above their broadest part, extend into upturned triangular spines. The edge of the varices is crenulated and wavy. Viewed from the aperture side, the varices on each whorl have an overlapping, folded-over layer which is tightly appressed; the edge of the overlapping layer begins at the tip of the triangular spine and curves down in a gradually widening segment. The aperture is ovate, small and entire; it is notched slightly above the opening to the siphonal canal, and in addition it is notched where the double layered portion of the varical spine begins. Both parietal and labial areas of the apertural lip are erect. The siphonal canal is long, broad, and is slightly opened in the holotype and closed in the paratype. The edge of the canal, on the parietal side, adherently overlies along its length a portion of the canal; the canal is not recurved except for the tube-like open distal end which is sharply bent back. Two previous canals remain on the siphonal fasciole. The shell is microscop- ically, spirally striate except for some strong striae present in the region of the larger body tubercle. Color: In the holotype, there are faint red-brown spiral bands at the aperture on the edge of the labrum, with 5 additional spiral bands on the canal. The spiral color bands rapidly fade away from their strong beginning. They persist, however, on the attachment portions of earlier varices. The paratype lacks coloration (owing to fading?) and is porcellaneous white. Opercular and radular characters are not known. Holotype: Los Angeles County Museum No. 1230, trawled by the “Ariel Expedition,’ in 25 fathoms from Loreto Channel, Baja California, Mexico, on gravel and coral shell bottom, August 29, 1960 (type locality). Sorted from trawl samples by G. Bruce Campbell. Length 29.0 mm, width 21.9 mm. Paratype: Los Angeles County Museum No. A.H.E 448-35, dredged by the Hancock Foundation vessel “Velero III” in 12 fathoms in sand off Secas Island, Pan- ama, 7°57'45”N, 82°00’45” W, February 5, 1935 (Fraser, 1943). Length 22.4 mm, width 12.7 mm. Remarks: The shell of the new species is morphologically similar to that of Pterynotus (Purpurellus) pinniger (Brop- ERIP) of the eastern Pacific and P (P) gambiensis (REEVE) from western Africa. It differs from the latter two species by its much smaller size; its comparatively greater width relative to height; and the lack of an indentation in the varical flange between the body whorl and the canal. The lamella in both P (P) gambiensis and P. (P) pinniger tend to have their edges more crenulated and recurved into spiny points and the spiral cords more developed. Ptery- notus (P.) pinniger has a larger, heavier, more elongate shell. All three of the Recent species have a similar pattern of coloration; the spiral color bands start somewhat strongly at the labrum and fade out rapidly before reach- ing the next varix. The lamellae on all three species are continuous with the body of the shell on their dorsal side. On their ventral side there is a distinct break between the thickened varices and the lamellae extending above; Page 148 THE VELIGER Vol. 12; No. 2 in addition, the sculpture of the ventral sides of the lamel- lae is finely multilaminate. The opercula of Pterynotus (Purpurellus) pinniger and P (P) gambiensis have a nucleus somewhat below and to the right of center. ACKNOWLEDGMENTS In addition to Drs. G. B. Campbell and J. H. McLean, and E. H. Vokes, we are most grateful to the following friends and colleagues for the loan of pertinent specimens: Mr. and Mrs. John Q. Burch of Seal Beach, California, Mrs. Ruth A. Craine of Norwich, New York, Dr. Donald R, Shasky of Redlands, California, Mr. Lawrence Thomas of Morro Bay, California, Mr. Joseph H. Peck, Jr., Muse- um of Paleontology, University of California, Berkeley, and Mr. and Mrs. Ben Purdy of San Diego, California. Dr. George E. Radwin of the San Diego Natural History Museum kindly provided a radular mount of Murex pin- niger from which the present illustration was drawn. Our colleagues, Miss Lynne Judge and Mr. William E. Old, Jr., assisted us in various ways. LITERATURE CITED BropeErip, WILLIAM JOHN 1833. | Characters of new species of Mollusca and Conchifera collected by Mr. Cuming. Proc. Zool. Soc. London for 1832: 173 - 179 (14 January 1833) DuruaM, Joun Wyatt 1950. 1940 E. W. Scripps cruise to the Gulf of California. Pt. II. Megascopic paleontology and marine stratigraphy. Mem. Geol. Soc. Amer., no. 43: 1 - 216; 48 plts. EMERSON, WILLIAM KEITH 1960. | Remarks on some eastern Pacific muricid gastropods. Amer. Mus. Novitates no. 2009: 15 pp.; 7 figs FiscHer, PAuL 1884 [1880 - 1887]. Manuel de conchyliologie et paléontologie conchyliologique. Paris, 1369 pp.; 23 plts. (fasc. 7, Muri- cidae, publ. in 1884) Fraser, CHARLES McLEAN 1943. General account of the scientific work of the Velero III in the eastern Pacific, 1931-41. Part III. A ten-year list of the Velero III collecting stations (charts 1 - 115). Allan Hancock Pacif. Exped. 1 (3): 256-431; 115 charts. Univ. So. Calif. Press, Los Angeles, California HAN Ley, SYLVANUS CHARLES 1841. Exotic conchology, by Witttam Swainson. Second ed. London, 39 pp.; 48 plts. JoussEAUME, FELIX PIERRE 1880. Division méthodique de la famille des purpuridés, Le Naturaliste, Paris, 1 (42): 335 - 336 REEvE, LovELL Aucustus 1845-1846. Conchologia Iconica: or Illustrations of the shells of molluscous animals. Monograph of the genus Murex. 3: plts. 1 - 36; 1 suppl. plt. (April 1845 to April 1846) Ropinc, PETER FriepRIcH 1798. Museum Boltenianum ... : pars secunda continens con- chylia sive testacea univalvia, bivalvia & multivalvia. Hamburg (Johan Christi Trappii) pp. i- viiit+1- 199 SHASKY, DONALD R. & G. BRUCE CAMPBELL 1964. New and otherwise interesting species of mollusks from Guaymas, Sonora, Mexico. The Veliger 7 (2): 114-120; plts. 21, 22: 1 text fig.; 1 map (1 October 1964) Swainson, WILLIAM 1822. Descriptions of several new shells, and remarks on others, contained in the collection of the late Mrs. Bligh, as appendix zn C. Dusots, A catalogue of the rare and valuable shells which formed the celebrated collection of the late Mrs. Bligh, London, illus. [not seen; Swatnson’s Bligh appendix reprinted by SytvaNus Han -ey, 1841]. 1829 - 1833. Zoological illustrations or original figures and descriptions of new, rare, or interesting animals, selected chiefly from the classes of ornithology, entomology, and conch- ology, and arranged according to their natural affinities. London, (Baldwin « Cradock), ser. 2, vol. 3, The shells. THIELE, JOHANNES 1929[-1931]. Handbuch der systematischen Weichtierkunde. Jena, Gustav Fischer, 1929 - 1935; 1154 pp.; 893 text figs. (pp. 1-376 publ. in 1929) VoKEs, Emity H. 1964. | Supraspecific groups in the subfamilies Muricinae and Tritonaliinae (Gastropoda : Muricidae). (1): 1-41; plts. 1-3; text figs. Malacoiscia Explanation of Plate 27 Pterynotus (Purpurellus) pinniger (BRODERIP, 1833) Figures 1, 2: Holotype of Centrifuga inezana DurHAM, 1950, pl. 26, figs. 1, 4, specimen with 4+ postnuclear whorls (early whorls lost), Pleistocene, Punta Santa Inez, Baja California, Mexico; approximately X2. Figures 3, 5: Specimen of 6+ postnuclear whorls, off Cabo Haro, Guaymas, Sonora, Mexico, 20 to 40 fathoms. Donald Shasky collection; <2. Figure 4: Lectotype of Murex pinniger (BRopERIP, 1833), Xipi- xapi, Ecuador, 8 fathoms, after EMERSON, 1960, fig. 7; X2. Figure 6: Specimen, partly encrusted with bryozoa, with 5+ postnuclear whorls, off Cabo Haro, Guaymas, Sonora, Mexico, 30 fathoms, G. Bruce Campbell collection; 2. [EMERSON & D’ArTILI0] Plate 27 ine) ° v Th i} © 0 S Fy AS ey Nn L al o> 2 5 &p AY a ky feo) = e 2 =) SI ot 0 Fa fy THE VELIGER, Vol. 12, No. 2 Wolel2 No; 2 THE VELIGER pagesta9 Two New Species of Galapagan Turrid Gastropods WILLIAM K. EMERSON Department of Living Invertebrates, American Museum of Natural History Seventy-ninth Street and Central Park West, New York, New York 10024 AND GEORGE E. RADWIN Natural History Museum, Balboa Park, P. O. Box 1390, San Diego, California 92112 (Plates 28 and 29; 5 Text figures) AMONG NUMEROUS MARINE MOLLUSKS kindly submitted by Mrs. Jacqueline DeRoy of Academy Bay, Isla Santa Cruz, the Galapagos Islands to the senior author for study are representatives of two new species of toxoglos- sate gastropods referable to the Turridae. The description of these interesting discoveries forms the basis of this report. We take great pleasure in dedicating this paper to our colleagues, Dr. Leo G. Hertlein of the California Aca- demy of Sciences and Dr. A. Myra Keen of Stanford University, both of whom have made numerous contribu- tions to Malacology. Hindsiclava HERTLEIN & STRONG, 1955 Hindsiclava HERTLEIN & STRONG, 1955, p. 227; type species: Pleurotoma militaris “Hinps” Reeve, 1843, by OD. Turrigemma Berry, 1958, p. 88, type species: Turri- gemma torquifer Berry, 1958, by SD (Berry, 1964, 154). Otsson (1964, p. 96) referred BeRRy’s Tur- rigemma to the synonymy of Hindsiclava. Remarks: The genus Hindsiclava was proposed for shells possessing strong axial ribs and cords to give a reticulate sculpture to the surface and with a well-developed node of callus at the sutural edge of the anal sinus. This anal node is apparently a gerontic character that does not appear in specimens with immature outer lips or in juveniles. The following nominal species from the Eastern Pacific are apparently referable to this genus, in addition to the type species, Pleurotoma militaris REEVE, 1843. 1. Turris (Surcula) resina Dati, 1908, p. 264, Gulf of Panama, in 322 fathoms (U.S. Fish Commission Station 3345), based on a single, large incomplete specimen with an anal node; Dati, 1919, p. 16, plt. 2, fig. 4 (holotype). This taxon was placed in the syn- onymy of Hindsiclava militaris by Otsson, 1964, p. 96. 2. Turris (Surcula) dotella Dati, 1908, p. 263, off Baja California, Mexico, 27 fathoms, holotype (U.S. Fish Commission Station 2823) and 2 paratypes off La Paz, Baja California, Mexico; Keen, 1958, p. 464, fig. 842 (holotype, U.S. N.M. No. 96731), an immature specimen lacking an anal node. 3. Turris (Surcula) notilla Dai, 1908, p. 263, off Cape San Lobos, Baja California, Mexico, in 58 fathoms, holotype (U.S. Fish Commission Station 3017), and 2 paratypes from same station. KEEN, 1958, p. 476, fig. 906 (holotype U.S. N.M. No. 110602), an immature specimen lacking an anal node, strongly resembling Hindsiclava dotella but with stronger axial sculpture. 4. Clathrodrillia andromeda Dauu, 1919, p. 16, plt. 2, fig. 2, off La Paz, Baja California, Mexico, in 10 fathoms; Kren, 1958, p. 464, fig. 841 (copy of Datt’s (1919) figure). The holotype is a small juvenile specimen, lacking an anal node. 5. Turrigemma torquifer Berry, 1958, p. 88, off Puerto Refugio, Angel de la Guarda Island, Mexico, in 65 fathoms. KEEn, 1958, p. 465, fig. 845 (holotype in collection of Dr. S.S. Berry?). This nominal species appears to be a junior synonym of Hindsiclava andromeda (Datt, 1919) ; the figured specimen of BErrRy’s taxon apparently represents a mature specimen. 6. Hindsiclava hertleini, new species, described below, from the Galapagos Islands. The genus Hindsiclava is apparently limited in fossil and present day distribution to the New World. In addi- tion to the record of Hindsiclava militaris REEVE in the late Neogene of Ecuador (Otsson, 1964), several nominal Page 150 species that appear to be referable to this genus are known from numerous deposits of Mio-Pliocene age in the Carib- bean region. For example, “Pleurotoma” consors SowER- BY (1850, p. 50), originally described from the Miocene of the Dominican Republic, was stated by SoweRBy to be an analogue of REEvE’s militaris. RutscH (1934, pp. 99 - 101, figs. 13 - 16) cited specimens of SoweErRBy’s spe- cics from the Neogene of Venezuela and he discussed representatives of the group of Hindsiclava consors (Sow- ERBY) then known from the East American region. He also pointed out the similarity of “Drilla” alesidota DALL (1889, p. 84) and “Drilla” macilenta DALL, (1889, p. 85, plt. 36, fig. 1), Recent species described from the Gulf of Mexico and off Barbados, to Hindsiclava consors. Hindsiclava militaris REEVE, 1843, ex Hinps MS (Plate 28, Figures 1 to 4; Text figures 1, 2) Pleurotoma militaris REEVE, 1843 [March], vol. 1, Pleurotoma, sp. 55, plt. 7, fig. 55, “Veragua, Central America’’[Pana- ma], 18 fathoms, mud, Hinds [type locality]. Clavatula militaris Hinps, 1843 [July], p. 38, Veragua [Pana- ma], 18 fathoms, Panama, 8 - 30 fathoms. Hinps, 1844, p. 16, plt. 5, fig. 10, Veragua, Central America [Panama], in 18 fathoms; Panama, in 8 - 30 fathoms. Drillia militaris “Hinps”, Tryon, 1884, vol. 6, p. 181, plt. 10, fig. 74 (copy of REEve’s (1843) figure). Pleurotoma (Drillia) militaris REEVE, WEINKAUFF, 1887, vol. 4, div. 3, p. 132, plt. 29, fig. 10. [?] Turris (Surcula) resina Dat, 1908, p. 264, Gulf of Pana- ma, in 322 fathoms, mud, U.S. Fish Commission ‘“Alba- tross” station 3354, 7°09’45” N, 80°50’00” W [type lo- cality]. [?] 2Clathrodrillia resina Dat, Dat, 1919, p. 16, plt. 2, fig. 4 (holotype; U.S.N.M.No. 123103); Pmssry & Ots- son, 1941, p. 18, plt. 2, fig. 1, Punta Blanca, Ecuador, Canoa formation, Pliocene. Hindsiclava militans “Hinps”, HERTLEIN « STRONG, 1955, p. 227, [in part, excluding reference to Clathrodrillia aeno- ne Dati, 1919], Pinas Bay, Panama, 14 - 33 meters; Ardita Bay, Colombia, 34-43 meters; Octavia Bay, Colombia, 24-28 meters, in gray sand, sandy mud, and _ black bottom. Orsson, 1964, p. 97, plt. 17, figs. 3, 3a, Quebra- da Camerones, Ecuador, Esmeraldas formation, late Mio- cene-early Pliocene. KEEN, 1958, p. 465, figured on frontispiece. Range: Off Magdalena Bay, Baja California, Mexico, through the Gulf of California, and south to Octavia Bay, Colombia (HERTLEIN & STRONG, 1955), off shore to 90 fathoms, ? 322 fathoms. Also reported as a fossil from late Neogene deposits of Ecuador (Pitssry « Oxsson, 1941; Otsson, 1964). ; Radular characteristics: Radular formula 1-0°0-0-1. A racemose cluster of 30-40 “duplex” uncinal teeth THE VELIGER Vol. 12; No. 2 attached to an almost invisible, vestigial radular ribbon and seemingly enclosed in a membranous sac (Text figure 1). Each tooth consists of two articulating parts, a broad, blade-like member and a narrower, stylet-like member. The two parts articulate proximally and lie parallel for most of their length (Text figure 2). The radular arrange- Figure 1 Figure 2 Hindsiclava militaris (REEVE, 1843) Figure 1: Several radular teeth in their natural grouping. Figure 2: Single tooth; both figures greatly enlarged. ment in Hindsiclava militaris, the type species of Hindsi- clava, suggests placement of this genus in the turrid sub- family Crassispirinae (see Morrison, 1966). Remarks: The type locality of Hindsiclava militaris is off Veragua, Panama, in 18 fathoms, based on specimens collected on the world-wide voyage of “H. M.S. Sulphur,” under the command of Captain Belcher, in 1836 - 1842 (see Hinps, 1844, p. 16, plt. 5, fig. 10). Hrnps’ preliminary description of this taxon did not appear until October of 1843 (Hinps, 1843), whereas REEveE’s description and figure of the taxon based on Hinp’s manuscript name ap- peared in March of 1843 (Reeve, 1843). Therefore, the authorship of this species must be credited to REEVE, 1843, on the basis of priority, as there is no evidence that H1nps provided the description that appeared in REEve’s (1843) monograph. It also should be noted that REEvE’s descrip- tion and those of Hinps (1843, 1844) are not identical. This fact further suggests that REEve (1843) prepared his own description for this taxon. KEEN (1966, p. 272) was unable to locate the type spe- cimens of Pleurotoma militaris REEvE in the Belcher- Hinds collection of the British Museum (Natural History). Before undertaking the description of the new species of Hindsiclava that appears below, we inquired of the offi- cials of the Mollusca Section of the British Museum Vol. 12; No. 2 regarding the presence of potential type material of REEVE’s taxon in their collection. They informed us that documented type specimens could not be located, but they kindly provided us with photographs of 3 specimens labeled “Pleurotoma militaris Hinps, Central America” from the Hugh Cuming Collection. Although these speci- mens do not now possess definite locality data, they may represent part of the original lot. In the absence of better documented material, these specimens are candidates for syntypic status. They are worn specimens, the largest two being slightly smaller (measuring 39 mm and 36 mm, respectively, in length), than the specimen illustrated by REEveE (1843, plt. 7, fig. 55), which, judging from the figure, is 45 mm in length. The largest and best preserved specimen from the Cuming Collection is illustrated here, Plate 28, Figure 2, for comparison with a copy of REEve’s original illustration, here copied, Plate 28, Figure 1." An examination of 12 lots of Hindsiclava miltaris in the collection of the American Museum, totaling nearly 75 specimens, reveals that a well-developed anal node is present on only 5 of the larger specimens. The smallest specimen possessing a node measures 42.5 mm in length, whereas the largest with a node measures 45.6mm in length. Similar-size specimens with immature outer lips lack a node (cf. Plate 28, Figures 3 and 4). Larger speci- mens attaining a maximum length of 50 mm, all of which appear to have immature outer lips, lack nodes. These data suggest that the presence of an anal node is a gerontic character of genetic significance that does not occur in juvenile individuals or in old specimens that have not developed a mature outer lip. It is possible, however, that the development of the node is the result of sexual di- morphism, or represents some other biological factor, but such conclusions must await further study. We have questionably placed Hindsiclava resina (DALL, 1908) in the synonymy of ReEEve’s H. militaris. DALL’s taxon was based on a single, incomplete specimen, that measures approximately 50 mm in length. This specimen possesses a partially developed anal node (Dati, 1919, plt. 2, fig. 4). It was stated to have been dredged in 322 fathoms in the Gulf of Panama. All live-collected speci- mens of Hindsiclava militaris that we have seen are from ' According to Dance (1966, p. 213), “The British Museum (Natural History) purchased 277 shells from [G. B.] Sowerby [3'4 of name], many of them described and figured in the Mol- lusca reports of the Sulphur and Samarang voyages.” Therefore, it would appear that part of Hind’s Sulphur-material was dis- tributed by the Sowerbys who were shell dealers, and the present specimens might have been obtained by Hugh Cuming from this source, or they could have been given to Cuming by Belcher or Hinds (see KEEN, 1966). THE VELIGER Page 151 stations on the continental shelf. Possibly this specimen was carried by turbidity currents or by some other means down the slope to this depth. Orsson (1964, p. 96) placed H. resina in the synonymy of H. militaris, and he stated: “Dati’s Clathrodrillia resina was described from a broken specimen (its length when perfect esti- mated at 88 mm.) dredged from a depth of 322 fathoms in the Bay of Panama.” We have not seen specimens of H. militaris that approach this size. HERTLEIN & STRONG (1955, p. 227), however, cite “A very large specimen [of H. militaris] in the collections of the California Academy of Science from the southern portion of the Gulf of Cali- fornia: length, 56.4 mm.; maximum diameter, 1.7 mm.” Da. (1908, p. 264) also mentions with reference to the description of Hindsiclava resina: “A large shell very much broken and eroded with a somewhat similar form and sculpture ” was dredged from 134 fathoms, near Cocos Island. The incomplete specimen measures about 58 mm in length and “It has a large amorphous mass of callus on the proximal end of the pillar, and [this] may be a pathological feature.” This would appear to be a reference to a well-developed anal callus. Dati did not propose a name for the Cocos Island specimen because of the incompleteness of the shell. Clathrodrillia aenone Datu (1919, pp. 15 - 16), which was not illustrated at the time the taxon was proposed, was referred to Hindsiclava by HERTLEIN & STRONG (1955, p. 227). The holotype of Datt’s taxon was sub- sequently illustrated by Kren (1958, p. 454, fig. 770), who retained it in Clathrodrillia. vt} Hindsiclava hertleint EMERSON & RaADWIN, spec. nov. (Plate 28, Figures 5, 6; Text figure 3) Diagnosis: A medium-sized, slender species of Hindsicla- va, characterized by numerous, coarsely nodulose, axial ribs (23 on body whorl of holotype), crossed by dark chestnut-brown lirations, over an of-white base. Aperture white, tinged with buffyellow. Description: Shell slender, spire acuminated, whorls shouldered; axial sculpture of slightly nodulose ribs, 20 to 23 on the body whorl; spiral sculpture of depressed lirae which decussate the axial ribs to form coarse nodules; body whorl with 7 major spirals of equal size and 1 minor spiral just below the suture, with 5 minor spirals at the base of the siphonal canal; spire consists of 33 smooth nuclear whorls, and 8 sculptured, postnuclear whorls, which become progressively more strongly ornamented posteriorly; a narrow, weakly nodulose sutural collar is present above the suture on the spire, followed by 2 major nodulose axials, each divided by a narrow depressed Page 152 lira; outer lip thin with a moderately developed anal notch, lacking an anal callus in the holotype and the paratypes (presumably because of the immaturity of the specimens). Exterior off-white, with spirals and sutures dark chestnut-brown; interior white with inner lip and parietal wall tinged bright buff-yellow. Periostracum thin, nearly transparent, pale straw color. Radular characteristics: Radular formula 1:0:0-0-1. A racemose cluster of approximately 30 “duplex” uncinal teeth attached to a somewhat vestigial radular ribbon and seemingly enclosed in a membranous sac. Each tooth consists of two parts, a broad, blade-like member and a narrower, stylet-like member. The two parts articu- late proximally and lie parallel for most of their length (Text figure 3). This type of radular dentition, typical of Hindsiclava, as shown earlier, suggests that this species and H. militaris should properly be assigned to the turrid subfamily Crassispirinae (see Morrison, 1966). Measurements: holotype 36.5 mm in length, 11.6 mm in width; largest paratype 31.7:mm in length, 9.1 mm in width (incomplete specimen). Figure 3 Hindsiclava hertleini EMERSON & RADWIN, spec. nov. Single radular tooth; greatly enlarged. THE VELIGER Volel2 Now Type locality: South of Isla Daphne, Galapagos Islands, in 101 meters. J. DeRoy, November 25, 1967 (holotype, see Plate 28, Figure 5; and 1 paratype). Type depositories: holotype, A. M.N.H.No. 150514; 1 paratype A.M.N.H.No. 152603 (dead specimen), May 27, 1967, Plate 28, Figure 6); 1 paratype S.D.N. H. S. No. 50768, December 9, 1968; 1 paratype, A. D’At- tilio Collection, December 9, 1968; all from off Santa Cruz Island, Galapagos Islands in 73 - 91 meters. Remarks: The holotype is a fresh, apparently live-taken specimen, whereas one paratype is a dead-collected, bleached specimen lacking the early whorls of the spire and part of the outer lip. The two other paratypes are live-collected specimens. All specimens appear to have immature outer lips and lack an anal callus in this stage of development. The new species resembles Hindsiclava militaris in general features but differs in the narrower, sutural collar, more angular shoulder, fewer spirals and coarser nodes on the body whorls, as pointed out by Dr. Hertlein (in litt.), who kindly examined two of the Galapagan specimens. The periostracum of H. militaris is a greenish-brown while that of the new species is a pale straw-yellow. Lioglyphostoma variculosa (SowERBy, 1834, p. 139; Reeve, 1843, plt. 22, fig. 194), described from off west Panama and reported also from Mazatlan, Mexico (KEEN, 1958, p. 464), appears to have similar ornamentation, but it has fewer axial ribs. We have not seen specimens re- ferable to this taxon. Mitrolumna Bucqguoy, DAUTZENBERG « DoLiLFus, 1883 Mitrolumna Bucguoy, DauTzENBERG & Do.irus, 1883, p. 121; type species: Mitra olivoidea CANTRAINE, 1835, by OD. PowELL, 1966, p. 67 (synonymy and remarks). Clinomitra BELLARDI, 1889, p. 152; type species: Clinomitra rovasendae Breviarpi, 1889, by M, a Miocene fossil. Diptychomitra BELLARDI, 1889, p. 152; type species: Diptycho- mitra eximia BELiarpI, 1889, by SD (Cossmann, 1899, p. 174), a Miocene fossil. Explanation of Plate 28 Figures 1, 2a, 2b, 3a, 3b, 4a to 4c: Hindsiclava muilitaris REEVE, 1843, type species of Hindsiclava HERTLEIN & STRONG, 1955. Figure 1: copy of illustration of Hinps, 1843, plt. 5, fig. 10; 1.25. Figures 2a, 2b: probable syntypes, Hugh Cuming Collection, British Museum (photograph courtesy and © of British Museum (Natural History) ); 1.25. Figures 3a, 3b: 146-165 meters, Gorda Banks, Baja California, Mexico, Templeton Crocker Station 150-D-12; 1.25 (note well- developed anal node). Figures 4a to 4c: 101 - 183 fathoms, Arena Bank, Baja California, Mexico, Templeton Crocker Station 136-D-17; X1.25 (note the lack of an anal node). Figures 5a, 5b, 6a, 6b: Hindsiclava hertleini EMERSON & RADWIN, spec. nov. Figures 5a, 5b: Holotype, with periostracum; X2. Figures 6a,6b: Paratype, dead, worn specimen, lacking early whorls; X2. THE VELIGER, Vol. 12, No. 2 [EMERSON & Rapwin] Plate 28 He E E E = E E Figure 3a Figure 3b Figure 4 a Figure 4 b Figure 4 c Figure 6 a Figure 6 b Vol. 12; No. 2 THE VELIGER Page 153 Remarks: Originally established for species having shells intermediate in appearance between some species of Mitra and Columbella, this genus appears to be related closely to Mitromorpha CarPENTER, 1865 (not Mitromorpha A. ApaMS, 1865), type species: Mitromorpha filosa CARPEN- TER, 1865 [= M. carpenteri GuiBEert, 1954]. The major difference seems to be the presence of two well-formed median pillar plicae in Mitrolumna. The radular dentition suggests a close relationship between these two genera, cf. Text figures 4, 5 herein with the text figure 123 of Powe Lv (1966), a radular illustration of the type species of Mitromorpha. Until the discovery of the new Galapagan species, the only living representative of the genus Mitrolumna known was the type species M. olivoidea CANTRAINE, 1835 from the Mediterranean and north Atlantic. In addition, the following Miocene species were assigned to Mitrolumna by PowE.y (1966, p. 67): canaliculata BELLARDI, 1889; clathrata BELLARDI, 1889; cancellata PEyYRoT, 1938; doll- fusi Pryrot, 1938; filifera BELLARDI, 1889; michaudi MicHeE.Lottl, 1847; and rovasendae BELLARDI, 1889. Mit- rolumna olivoidea is also known from the European Plio- cene and Pleistocene. It should be noted in passing that the well-known spe- cific name filosa CARPENTER in the genus Mitromorpha CarRPENTER was validly replaced with M. carpenteri by Gupert (1954, p. 43) owing to the fact that GLIBERT had assigned a European Miocene species, Columbella filosa Dujarpin (1837, p. 302), to the genus Mitromor- pha (s. s.). Thus, CARPENTER’s specific name filosa became a junior secondary homonym, and Mitromorpha carpen- tert was proposed by GLiBERT as a replacement name for M. filosa CarPENTER, 1865, not M. filosa (Duyjaronin, 1837). Mitrolumna olwoidea (CANTRAINE, 1835) Mitra olivoidea CANTRAINE, 1835, p. 391, Mediterranean, Ad- riatic. TOMLIN & SHACKLEFORD, 1914, p. 245, Sao Thome, Canary Islands, and Mediterranean. Mitra columbellaria Scaccut, 1836, p. 10, figs. 12, 13, Naples, Italy. Mitra obsoleta Puiipr1, 1836, (not “Broccut,’ GRATELOUP, 1834, p. 290), vol. I, p. 230, Sicily, Italy. Columbella greci Putri, 1844, vol. II, p. 194, plt. 27, fig. 18, Sicily, Italy. Mitra striarella Catcara, 1841, p. 66, Sicily, Italy. Mitra clandestina ReEve, 1845, vol. II, sp. 253, plt. 32, fig. 263, no locality. Mitra columbellaris Scaccui, Petit, 1860, vol. 8, p. 258, “les cétes de la Provence,” (France). Mitrolumna olivoidea Bucquoy, DauTzENBERG & DOLLFUS, 18835 pan lee pli lon tess 33 .- Som (type), 301-139 (‘‘var.” [ieties]), Roussillon, France; synonymy and remarks. KnupsENn, 1956, p. 525, plt. 2, fig. 7, off Cape Vert, Senegal. Daurzenserc, 1889, p. 31, plt. 2, figs. 6a, 6b, Azores. Mitrolumna oliviformis CANTRAINE,; Locarp, 1892, p. 50, “Mediterranean.” Range: North Atlantic (Portugal, Nosre, 1932, to Sene- gal, KNupsen, 1956) through the northern Mediterra- nean (France, Bucguoy,DAUTZENBERG & Dot.Fus, 1883). also reported as a fossil from’ Pliocene and Pleistocene deposits of Europe. pa Remarks: Mitrolumna has long been considered mono- typic. Its type species, M. olivoidea, is now known to be the last survivor of the genus with several species in the Old World: Miocene and Pliocene. The discovery of a Recent species in the Galapagos Islands referable to Mitrolumna so far remote from the only other surviving ‘species seem- ingly presents zoogeographic incongruities. Assuming the correct generic assignment of the new Galapagan species, one can speculate that these surviving species are relict elements of a group that once enjoyed a much wider distri- bution. It may eventually be found to have a geological history similar to that of the related genus Mitromorpha CarPENTER. Representatives of that genus are recorded from the Pliocene and Pleistocene of California, Pliocene of Florida, and Miocene of Florida and France (Powe LL, 1966), with 4 Recent species known from Californian and west Mexican waters (KEEN, 1937; Coan, 1962) and at least one species living in the western Atlantic (DALL, 1889). The radular characters of the type species of Mitro- lumna apparently have not been illustrated or described, and we have not been successful in our efforts to extract a radula from the very limited number of specimens that were available for study. Mitrolumna keenae EMERSON & RaDWIN, spec. nov. (Plate 29, Figures 5, 6; Text figures 4, 5) Diagnosis: Shell moderately large for the genus (attaining 18 mm in length), biconical; characterized by numerous spiral incised lines on a buff-colored shell, with chestnut- brown axial maculations between the spiral incised lines which do not cross them. Description: Shell moderately slender, whorls unshoul- dered; spiral sculpture. of numerous fine, incised lines; axial sculpture completely lacking; body whorl with 27-30 glyptae with interspaces varying in width. Immediately be- low the suture there are 3 strongly incised lines alter- nating with 3 grooves of typical strength forming a series of 3 pairs of fine crowded striae; immediately below the periphery of the body whorl is another series of 3 to 5 Page 154 THE VELIGER Vol. 12; No. 2 crowded striae; remainder of the body whorl with regular sculpture; spire consisting of 34 smooth, glassy, trans- lucent-white nuclear whorls and 8 sculptured postnuclear whorls which become progressively more strongly sculp- tured posteriorly; outer lip thin with moderately devel- oped anal notch, interior of outer lip with 14 short, weak lirations. Exterior off-white with short chestnut-brown maculations, darkest on the crowded subsutural inter- spaces; a faint brown tinge on the peripheral group of 3 - 5 crowded interspaces; maculations randomly arranged on the interspaces but do not transverse the spiral incised lines. The present species has a typical toxoglossate dentition with a packet of 16 dart-like teeth, each about 10u long (Text figures 4, 5) in a lateral pharyngeal pouch; the packet remains cohesive during radular extraction as a result of the presence of a series of filaments which con- An 8 Mitrolumna keenae EMERSON & RADWIN, spec. nov. Figures 4 and 5: Two views of radular tooth; greatly enlarged. nect all the teeth together. A fragment of such a filament may be seen in Text figure 4. This type of radular dentition clearly shows the relationship of this species to others as- signed to Mitromorpha, and other borsonine and mangel- ine species (see Morrison, 1966; Powe 1, 1966). Measurements: holotype 16.8 mm in length, 6.5mm in greatest diameter; smallest paratype (from type locality) 13.3 mm in length; largest paratype 17.0 mm in length. Type locality: near Tagus Cove, Isabella Island, Galapa- gos Islands, dredged in 75-100 meters, January 25, 1968, by the DeRoys. Type depositories: holotype, A.M.N.H. No. 152601 (Plate 29, Figure 5) ; 1 paratype, A. M. N. H. No. 152602 (Plate 29, Figure 6); 1 paratype, S.D.N.H.S. No. 50769; 1 paratype, A. D’Attilio Collection; 1 paratype, J. DeRoy Collection. The paratypes are all from the type locality. Remarks: All the specimens in the type lot were live-taken. The holotype and one paratype (in the J. DeRoy Collec- tion) are fully mature, whereas the paratypes in the A. M.N.H., 8. D.N.H.S. and the A. D’Attilio Collections are evidently immature. The new species is generally similar to Mitrolumna olwoidea but differs from it in the following ways: 1) its shell is more than twice as large as that of M. olwoidea, 2) although both species have crowded spiral elements at the periphery of the body whorl, the spiral elements on spire whorls of M. olivoidea are strongly nodulose, where- as those of MM. keenae have an almost planar surface, 3) the body whorl of M. olivoidea is broader than that of M. keenae, imparting a stouter appearance to the shell of the former, and 4) the two columellar plicae, typical of the genus, are more strongly developed in M. olivordea. Another genus that was given consideration for place- ment of this new species is Artelia SHasxy (1961, p. 20, pit. 4, figs. 7-9), type species A. mitriformis, by original designation. Avielia, however, typically has a much nar- rower shell, a more constricted body whorl, a much nar- rower aperture, and spire whorls with less convex profiles (Plate 29, Figure 1). Unfortunately, the radular charac- ters of the type species of this eastern Pacific monotypic genus are not known. Explanation of Plate 29 Figures 1a, 1b: Arielia mitriformis SHAsKy, 1961, type species of Arielia SHasky, 1961; 73-86 meters off Puerto Escondido, Baja California, Mexico, “Puritan” Station 139; <3 (note predator’s drill hole, Figure 1b). Figures 3a, 3b: Mitrolumna keenae EMERSON & RADWIN, spec. nov. Figures 2a, 2b: juvenile specimen, paratype, with immature outer lip and lacking pillar plaits; <3. holotype, mature specimen; X3 (note artificial “drill” hole, Figure 3b, drilled in order to remove soft parts for radular study). THE VELIGER, Vol. 12, No. 2 [EMERSON & Rapwin] Plate 29 Figure 1a Figure 1b Figure 2a Figure 2b Figure 3a Figure 3b Vol. 12; No. 2 THE VELIGER Page 155 ACKNOWLEDGMENTS In addition to Mrs. Jacqueline DeRoy we are indebted to the following friends and colleagues for courtesies of vari- ous kinds: Mrs. Jean M. Cate, Dr. Eugene V. Coan, Mr. Anthony D’Attilio, Mr. Harold S. Feinberg, Miss A. Ful- lick, Dr. Maxime Glibert, Dr. Leo G. Hertlein, Miss Lynne Judge, Dr. A. Myra Keen, Mr. William E. Old, Jr., Mr. Richard E. Petit, Dr. Joseph Rosewater, and Dr. Donald R. Shasky. LITERATURE CITED ApaMs, ARTHUR 1865. | On some genera of Mollusca from the seas of Japan. Ann. Mag. Nat. Hist., London (3) 15 (88): 322 - 324 (April) Berry, SAMUEL STILLMAN 1958. Notices of new Eastern Pacific Mollusca. — II. Leaflets in Malacol. 1 (15): 83-90 (28 March 1958) 1964. Notices of new eastern Pacific Mollusca — VI. Leaflets in Malacology 1 (24): 147 - 154 (29 July 1964) Bucguoy, E., PHitippe DaurzENBERG & G. DoLLFus 1883. Les mollusques marins du Roussillon. Paris, vol. 1, fasc. 3. Familles: Pleurotominae, Volutidae, Cypreadae [sic.], pp. 85 - 135; atlas plts. 11-15 Catcara, P. 1841. Mem. Conch. Allavilla. Palermo [not seen] CanTRAINE, Francois JosEPH 1835. ““Mollusques.” (10): 380-401 CarPENTER, PHILIP PEARSALL 1865. Diagnoses of new forms of mollusks, from the west coast of North America, first collected by Col. Jewett. Ann. Mag. Nat. Hist., ser. 3, 15: 177 - 182 (March 1865) ; 394 - 399 (May 1865) Coan, EuceNne Victor 1962. Notes on some tropical west American mollusks. The Veliger 5 (2): 92 (1 October 1962) CossMANN, ALEXANDER EpouaRD MAUuRICE 1899. _—_ Essais de paléoconchologie comparée 3. Paris (chez Pauteur) pp. 1 - 201; plts. 1-8; 35 text figs. (Apr. 1899) Dance, STANLEY PETER 1966. Shell collecting: an illustrated history. Press, Berkeley & Los Angeles, 344 pp.; 35 plts. Dati, Witiiam HEALEY 1889. Reports on the results of dredging Mexico and in the Caribbean Sea by the U.S. Coast survey steamer “Blake” Part 2, Gastropoda and Scapho- poda. Bull. Mus. Comp. Zool. 18: 1 - 492; plts. 10 - 40 1908. Reports on the dredging operations off the west coast of Central America to the Galapagos, to the west coast of Mexico, and in the Gulf of California. . XIV. The Mollusca and Brachiopoda. Bull. Mus. Comp. Zool., Harvard 43 (6): 205 - 487; 22 plts. (October 1908) Bull. Acad. Roy. Sci. Bruxelles, 1835 Univ. Calif. in the Gulf of Dai, WittiAM HEALEY 1919. Description of new species of mollusks of the family Turritidae [stc.] from the west coast of America and adjacent regions. Proc. U.S. Nat. Mus. 56 (2288) : 1 - 86; plts. 1 - 24 (8 August 1919) DAUTZENBERG, PHILIPPE 1889. Contribution a la faune malacologique des Iles Agores. Résult. Camp. Monaco 1. DuyJARDIN, FELIX 1837. | Mémoire sur les couches du sol en Touraine et descrip- tion des coquilles de la Craie et des Faluns. Soc. Géol. France, Mém. 9: 211-311; plts. 15 - 20 GLIBERT, MAXxIME 1954. Pleurotomes du Miocéne de la Belgique et du Bassin de la Loire Mém. Inst. Roy. Sci. Nat. Belg. 129: 1 - 75; plts. 1-7 GraTELoup, J. PS. 1834. Tableau (suite du) des coquilles fossiles qu’on rencontre dans les terrains grossiers (faluns) du Bassin géologique de Adour (Landes). Actes Soc. Linné. Bordeaux 37 (Zool.) : 270 - 320 Hertvein, Leo GeorcE & ARCHIBALD McCiure STRONG 1955. | Marine mollusks collected during the “Askoy” Expedi- tion to Panama, Colombia, and Ecuador in 1941. Bull. Amer. Mus. Nat. Hist. 107 [article 2]: 159-318; plts. 1-3 (28 November 1955) Hinps, RICHARD BRINSLEY 1843. | On new species of Pleurotoma, Clavatula, and Mangelia. Proc. Zool. Soc. London, Prt. XI: 36-46 (October 1843) 1844-45. The zoology of the voyage of H. M.S. Sulphur Mollusca, pt. 1, pp. 1-24, pls. 1-7 (July, 1844) ; pt. 2, pp. 25-48, pls. 8-14 (Oct. 1844) ; pt. 3, pp. 49-72, pls. 15-21 (Jan. 1845) [exact dates from a copy with original wrappers in the library of the California Academy of Sciences]. Keen, A. Myra 1937. An abridged checklist and bibliography of west Ameri- can marine Mollusca. Stanford Univ. Press, 87 pp.; 3 figs. 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi+624 pp.; 10 colored plts.; 1700 text figs. Stanford Univ. Press, Stan- ford. Calif. (5 December 1958) 1966. | West American mollusk types in the British Museum (Natural History), II. Species described by R. B. Hinps. The Veliger 8 (4): 265 - 275; plts. 46, 47; 6 text figs. (1 April 1966) KNUDSEN, JORGEN 1956. | Remarks on a collection of marine prosobranchs from Senegal. Bull. Inst. Frang. Afr. Noire, Dakar, ser. A, Sci. Nat. 16 (2): 514-529; plt. 2 Locarp, ARNOULD 1892. Les coquilles marines des cétes de France. et Fils. Paris. 384 pp.; 348 figs. Morrison, JosEPpH PauL ELDRED 1966. On the families of Turridae. Malacol. Union for 1965: 1, 2 Nosre, AUGUSTO 1932. | Moluscos marinos de Portugal. Porto, Portugal Bailliére Ann. Rept. Amer. 459 pp.; 80 plts. Page 156 Oxtsson, AxEL ADOLF 1964. | Neogene mollusks from northwestern Ecuador. Ithaca, New York (Paleont. Res. Inst.) pp. 1 - 256; plts. 1 - 38 (October 1964) PETIT DE La SAUSSAYE, S. 1860. | Nouveau supplément au catalogue des mollusques ma- rins qui vivent sur les cétes de France. Journ. Conchyl. Paris 8 (ser. 2, 4): 234 - 260 Puitipr1, RUDOLF AMANDUS 1836. | Enumeratio Molluscorum Siciliae cum viventium tum in tellure tertiaria fossilium quae in itinere suo observavit 1. Berolini (Halis Saxonum). pp. i- xiv + 1 - 268; plts. 1-12 1844. Enumeratio Molluscorum Siciliae, cum viventium tum in tellure tertiaria fossilium quae in itinere suo observavit 2. Berolini (Halis Saxonum). pp. i-iv+1- 303; plts. 13 - 28 Pitspry, HENry Aucustus « AxEL ADOLF OLSSON 1941. A Pliocene fauna from western Ecuador. Proc. Acad. Nat. Sci. Philadelphia 93: 1-79; plts. 1-19; 1 photograph (9 September 1941) PowELL, ARTHUR WILLIAM BADEN 1966. The molluscan families Speightiidae and Turridae. Bull. Auckland Inst. & Mus., No. 5: 184 pp.; 23 plts. REEVE, LovELL AUGUSTUS ; 1843[-1846]. Conchologia iconica: or illustrations of the shells of molluscous animals. London, vol. 1, Monograph of the genus Pleurotoma, plts. 1 - 40 [pts. 7. 8, March 1843] [1844-]1845. Conchologia iconica: or illustrations of the shells of molluscous animals. London vol. 2, Monograph of the genus Mitra, plts. 1 - 39 [pts. 31-39, March 1845] THE VELIGER Vol. 12; No. 2 Rutscu, R. 1934. Die Gastropoden aus dem Neogene der Punta Gavilan in Nord-Venezuela. Abhandl. Schweiz. Palaeont. Gesellsch. 54 (3): 1-88; 11 figs.; plts. 1-7; 55 (1): 89-169; 9 figs.; pits. 8, 9 Scaccur, ARCANGELO 1836. | Catalogus conchyliorum Regni Neapolitani quae usque adjue reperit Naples (Fitiatre-Sebetii). pp. 1 - 18, 1 plt. (also reprinted in 1857) Suasky, DonaLp R. 1961. | New deep water mollusks from the Gulf of California. The Veliger 4 (1): 18-21; plt. 4, figs. 1-10 (1 July 1961) Sowersy, GeorcE BrETTINGHAM (1‘T of name) 1834. | Characters of new species of Mollusca and Conchifera, collected by Mr. Cuming. Proc. Zool. Soc. London for 1833 (1): 134-139 (16 April 1834) Sowerby, GeorcE BRETTINGHAM (2%? of name) 1850. Description of new species of fossil shells found by J. S. Heniker [szc.]. Quart. Journ. Geol. Soc. London 6 (44) : 44 - 53; plts. 9, 10 [not seen] Tomuin, JoHN Reap LE BrockTon «& L. J. SHACKLEFORD 1914. The marine Mollusca of Sao Thomé, 1. Conch. 14 (8): 239 - 256 Tryon, Grorce WASHINGTON, Jr. 1884.- Manual of Conchology. Philadelphia, ser. 1, vol. 6, Family Pleurotomidae, pp. 151 - 413; plts. 1 - 34 WEINKAUFF, HEINRICH KonraD & W. KoBELT [1875-]1887. Die Familie Pleurotomidae begonnen von H. C. WeEInkauFF, fortgesetzt und beendet von W. KoBELT. ‘In Systematisches Conchylien-Cabinet von Martini und Chemnitz. Niimberg 4 (3): 1-248; plts. 1-43 Journ. Vol. 12; No. 2 THE VELIGER Page 157 Escape Responses of Three Indian Molluscs A. D. ANSELL The Marine Station, Millport, Isle of Cumbrae, Scotland INTRODUCTION THE MARINE MOLLUSCs exhibit a wide range of defensive responses to predators, including a variety of active mus- cular reactions, often leading to flight by an accelerated normal locomotory gait or by some mode of locomotion not normally employed. In recent reviews of these respon- ses FEDER & CHRISTENSEN (1966) and ANSELL (1969a) have brought together a synopsis of many scattered refer- ences to this phenomenon which clearly indicate that specific responses are characteristic of certain families or groups of families indicating a common and presumably ancient origin for the response. Certain groups of the bi- valves and gastropods thus apparently possess the poten- tiality to respond to potential predators, and representa- tives of these groups from different geographical areas or habitats may also be expected to exhibit similar responses. This is the case in the records presented here, which are of interest since they relate to molluscs from the tropics, while most of the previous records refer to species from temperate seas. The responses were observed in the labor- atory, in small aquaria, either at the Biological Oceano- graphy Division of the Indian National Institute of Oceanography, Ernakulam, South India, or at the Centre for Advanced Studies in Marine Biology, Porto Novo. OBSERVATIONS Mactra olorina Putipri, 1846 (Bivalvia, Eulamellibranchia, Mactridae) This species of Mactra, collected from sand near low water from a beach near Shertallai, some 20 miles south of Emakulam, exhibited the typical bivalve leaping re- sponse when contacted on the siphon or mantle margins by the foot of the predaceous gastropod Oliva gibbosa (Born, 1778). The leaping response which occurred from either the buried position or from the surface of the sand was essentially the same as that described for the temper- ate mactrid, Mactra corallina (LinNaEus, 1758) (AN- SELL, 1969b). Repeated stimulation resulted after a short time in a failure of the bivalve to respond by leaping, although there was an increase in shell gape, a reaction which together with the extension of the siphons to their full length always occurs before leaping. The leaping movements need not be described here since they show no special features different from those of Mactra corallina. Oliva gibbosa and Mactra olorina were both collected from the beach at Shertallai, during January, 1968. The general adaptations of these species to life on a surf- washed tropical beach will be described elsewhere, but 1/7. olorina is a fast burrowing active form whose normal buried position is with the dorsal shell margins just covered by the sand, while O. gibbosa is an active predator, moving through or over the sand by means of a large foot. At Shertallai, Oliva was found near high water mark at low tide, and only during January of the period Janu- ary to April, although it is not known whether its dis- appearance later was caused by migration offshore, or by local predation by the fishing community along the shore, who utilize all types of shellfish food. Probably both play a part, for CricHton (1942) records that on the east coast of India near Madras, O. gibbosa is to be found on the shore for a brief season only, early in February each year. The feeding habits of the Olividae are not well known. Members of the family are common in the faunas of sand beaches in the tropics and warm temperate zones, and it may be expected that they will be found to elicit escape responses from molluscs and other inverte- brates from such habitats. At Shertallai, other molluscs collected from the sand included Donax incarnatus GMEL- IN, 1791; the venerid Timoclea imbricata (J. DE C. SoweErBy, 1826), Sunetta solanderu (Gray, 1821) and the gastropod Bullia melanoides (DESHAYES, 1832). None of these showed any response to O. gibbosa, but of these Donax and Bullia are extremely active forms which exhibit tidal migrations and hence any further specific response to predators is probably unnecessary. The food of Oliva at Shertallai could not be determined, but may include some Donax which have been stranded by the receding tide, since such stranded Donax and Oliva both occurred in a narrow zone near the high water mark. Page 158 Umbonium vestiarium (LinnaEus, 1758) (Gastropoda, Prosobranchia, Trochidae) The response of Umbonium, which was observed at Porto Novo, was observed in an aquarium in which Umbonium was present together with the carnivorous gastropod Bursa Spinosa (LaMaRCK, 1816). These two species are not nor- mally sympatric, and so these observations merely indicate the ability of Umbonium to perform escape responses, but do not indicate the predator which normally evokes such responses. Umbonium responds by performing a series of rolling movements produced by the action of the foot which twists from side to side to push against the sub- stratum after the animal has rolled over to lie on the shell with the foot extended into the water. The move- ments are essentially similar to those performed by some members of the Trochidae, and especially Calliostoma zizyphinum (LINNAEUS, 1758) (FEpDER, 1967; ANSELL, 1969a), in response to contact with certain asteroid star- fish. Umbonium is a common species on the surf-washed sandy beaches near Porto Novo, and shows interesting modifications of the basic trochid structure which enable it to exploit this habitat. In the aquarium it exhibits considerable activity, and movements of the same type as the escape response occur apparently spontaneously. It is likely that similar movements are used in active move- ment on the shore, perhaps as in some bivalves represent- ing a response to lack of suitable substrata for burrowing (ANSELL, 1969b) or, as in the stenoglossan gastropod Bullia melanoides, contributing to a complex behavioural pattern by which the animal migrates up and down the shore with each tidal cycle. In the aquarium similar movements to those of the escape response also occur when one Umbonium touches another while crawling and similar intra-specific reactions were also noted for Bullia melanoides from Shertallai Beach. Babylonia spirata (LINNAEUS, 1758) (Gastropoda, Prosobranchia, Buccinidae) The conditions under which the response of Babylonia was observed were also artificial and probably inno way repre- sent a normal provocation. The specimen of Babylonia had been placed for observation in a large glass vessel which already contained a single individual of the volutacean Harpa conoidalis Lamarck, 1822 and 2 Bursa spinosa. After a short time the Bursa attacked the Harpa, which retracted when pierced by the proboscis of the Bursa and produced a copious secrétion of mucus. The Bursa was disturbed and withdrew the proboscis, and during this THE VELIGER Vol. 12; No. 2 disturbance the response of the Babylonia, which was nearby, was observed. The response consisted of the ani- mal turning so that it lay on the side of the shell with the foot extended in the water. A series of rolling /leaping movements followed caused by a vigorous rotation of the foot to press against the substrata first on one side and then the other so that the shell is moved actively over the surface in a zig-zag course. These movements are pro- duced in the same way as, and are similar in essentials to, the escape responses of the temperate buccinid Buccinum undatum LINNAEUS, 1758 or of members of the family Nassidae (FEDER, 1967). It is possible that some secretion from the withdrawn proboscis was responsible for eliciting the response. DISCUSSION These three examples of defensive responses by molluscs from India present further evidence for the occurrence of similar responses within certain groups of molluscs. Thus the two gastropod groups represented, the Buccinacea and the ‘Trochacea, together with the Zeugobranchia and Patellacea, comprise a majority of the previous records of locomotory responses by marine gastropods (ANSELL, 1969a). The members of the latter three groups are almost exclusively inhabitants of rocky shores, and it is therefore of considerable interest to find exactly similar responses exhibited by a species which has become adapt- ed to life in the disturbed environment of a tropical surf-washed sand beach. Responses of this kind are appar- ently of as much significance in the community relation- ships of sand dwelling forms as they are in those of rocky shores, which have provided most of the earlier examples. This view receives support from the occurrence of a response in the sandy-shore bivalve Mactra olorina. In addition, this reaction is interesting since, although several examples have been described of reactions by herbivorous gastropods to the presence of, or contact with, carnivorous gastropods, most previous records of leaping responses by bivalves are of responses to asteroid starfish, the only ex- ceptions of which I am aware being these of Ensts directus (Conrad, 1843) which Turner (1955) described as emerging from the sand in response to an attack by the predaceous snail Polinices duplicata (Say, 1822) and the reactions of Mactra sp. to Natica millepunctata LAMARCK, 1822 and N. hebraea and Spisula solida (LINNAEUS, 1758) to Lunatia nitida (Donovan, 1803) described by Hirscw (1915) and ZiecELtmerer (1954) respectively. There are no previous records of a member of the Oliv- idae being responsible for eliciting escape responses in other invertebrates. Wal 1 2:No: 2 THE VELIGER Page 159 These three examples in part extend our knowledge of defensive responses to a tropical fauna. The great variety of species in tropical faunas and the resultant complexity of the communities suggest strongly that such responses may play an even more important role in community interrelationships in the tropics than they do in temperate waters. The numerical superiority of records of such re- sponses from temperate forms probably reflects no more than the greater opportunities at present available for collection and observation of marine molluscs in temperate regions. ACKNOWLEDGMENTS The observations were made during a collaborative pro- gramme of study of sand beaches under the International Biological Programme by the Marine Laboratory, Aber- deen, and the Biological Oceanography Division of the Indian National Institute of Oceanography, Ernakulam, supported by a grant to Dr John Steele from the Royal Society of London. I am grateful to Dr Steele for an invitation to take part in this study and to the Royal Soci- ety for its financial support. It is a pleasure to thank Dr S. Z. Qasim, Director, Biological Oceanography Divi- sion, Indian National Institute of Oceanography for hospitality and for facilities provided at his laboratory, and Professor R. V.Sheshaiya and Dr R. Natarajan of the Institute of Advanced Studies in Marine Biology, Porto Novo for their help in providing and identifying an impressive collection of living molluscs during a very short visit. I am also indebted to Mr H.E. J. Biggs, British Museum (Natural History), who identified some of the molluscs from Shertallai. LITERATURE CITED ANSELL, ALAN Davip 1969a. Defensive adaptations to predation in the mollusca. Symp. Mar. Biol. Assoc. India (in press) 1969b. Leaping movements in the Bivalvia. Soc. London (in press) CricHton, MarsHALL DitwortTH 1942. Marine shells of Madras. Soc. 42: 323 - 341 FeperR, Howarp MITCHELL 1967. | Organisms responsive to predatory seastars. Sarsia 29: 371 - 394 FepER, Howarp MitTcHELL & AAGE MoLLER CHRISTENSEN 1966. Aspects of asteroid biology. pp. 87-127 In: Physio- logy of Echinodermata, RicHarp A. Boo.Lootian (ed.). Intersci. Publ. (Wiley), New York. Hirscu, Gottrwatt Cur. 1915. Die Emiahrungsbiologie fleischfressender Gastropoden. Zool. Jahrb., Abt. Allg. Zool. 35: 357 - 504 Turner, Harry Jackson, Jr. 1955. How clam drills capture razor clams. 69 (1): 20-22 ZIEGELMEIER, ERICH 1954. | Beobachtungen tiber den Nahrungserwerb bei der Nati- cide Lunatia nitida Donovan (Gastropoda Prosobranchia) . Helgol. Wissensch. Meeresunters. 5: 1 - 33 Proc. Malacol. Journ. Bombay Nat. Hist. The Nautilus Page 160 THE VELIGER Vol. 12; No. 2 Identification of the Feeding Types in the Genus Conus LINNAEUS BY Cc. F LIM Department of Zoology, University of Singapore, Singapore (Plate 30; 5 Text figures; 2 Tables) THE PREDATORY AND HIGHLY VENOMOUS gastropod genus Conus has been established to be distinctly vermivorous, molluscivorous, or piscivorous (KoHN, 1959a; ENDEAN & a2 Rupkin, 1965; Lim, 1968). It is also established that these three feeding types in Conus can be ascertained by examining the peculiarities in the anatomy of their radu- lar teeth (ENDEAN & RuDKIN, op. cit.). So far no at- tempts have been made to recognize the feeding types by shell characters which would be convenient. It is the intention here to try to do this, to try to assess the ratios among the three feeding types and also to review the § radular teeth characters in Conus. THE RADULAR TEETH CHARACTERS ENDEAN & RupkIN (1965) have already described the diagnostic characters that could identify the feeding type in the genus Conus. Basically, these are fairly reliable as one might expect that the radular teeth would be well adapted to the type of feeding. In review I am presenting in Figure 1 an assortment of radular teeth to give an illus- tration of the range of tooth-form existing in the genus. Conus magus LINNAEUS, 1758, a widely distributed pisci- vore in the Indo-Pacific region, possesses the typical form of radular teeth for its feeding type (Figure 1, P 1). It is (adjacent column —>) Figure 1 Radular teeth in Conus Pi: Conus magus LINNAEUS, 1758 (piscivore) P2: C. tulipa LINNAEUS, 1758 (piscivore) Mu: C. textile LinNAEUS, 1758 (molluscivore) M 2: C. marmoreus LINNAEUS, 1758 (molluscivore) V: C. betulinus LinnaEus, 1758 (vermivore) b = barb; 1 = ligament; 's = shaft Scale = 1mm Vol. 12; No. 2 a form similar to that seen in C. consors SowERBY, 1833, C. monachus LINNAEUS, 1758, C’. purpurascens SOWERBY, 1833, and C. striatus LINNAEUS, 1758 (Lim, 1968; PEILE, 1939; Koun, 1959a). Conus tulipa LinNaAgEvs, 1758 (Fig- ure 1, P 2), which is another piscivore, has radular teeth which resemble the molluscivorous type more closely than the typical piscivorous form. This is also true in the case of C. geographus LINNAEUS, 1758, yet another piscivore (ENDEAN & RuDKIN, op. cit.). The typical molluscivore form of radular teeth is exemplified in C’.. textile LINNAE- us, 1758, which is a widely distributed species in the Indo- Pacific (Figure 1, M 1). A not-so-typical tooth but showing all the molluscivore characters is seen in C’. marmoreus Linnaeus, 1758 (Figure 1, M 2). Finally, in the vermi- vores the radular teeth are rather uniform in structure as in C. betulinus LinnNazus, 1758 (Figure 1, V). Teeth similar to this have already been seen in C. caracteristicus FiscHer, 1807, C. maldivus Hwass, 1792, C. monile Hwass, 1792, C. striatellus Linx, 1807, C. coronatus Gmeun, 1791, and many other vermivores (PEILE, 1939; Koun, 1959a; and others). RATIOS AMONG THE FEEDING TYPES Fifty-five species of Conus from various parts of the world were considered for the determination of ratios among the vermivorous, molluscivorous, and piscivorous feeding types (Table 2). They were chosen because of their feeding types being known either from studies of their radular teeth or gut contents or feeding observations. The results of analyses revealed that 36 species were vermivorous, 9 molluscivorous, and 10 piscivorous. This works out to 65.46% vermivores, 16.36% molluscivores, and 18.18% piscivores (Table 1). An approximation of this would be a ratio of 4-5: 1: 1 for vermivores, molluscivores, and piscivores respectively. Table 1 Ratios of Conus species according to feeding-type Number of Conus species considered 55 Percentage of vermivores (V) 65.46% Percentage of molluscivores (M) 16.36% Percentage of piscivores (P) 18.18% Approximate ratios of V:M:P = 4-5:1:1 THE SHELL CHARACTERS The most striking shell character of Conus consists of the colour patterns or markings on the outer surface immedi- THE VELIGER Page 161 ately beneath the periostracum. There is a great variety of these markings, and attempts to sort the feeding types of the species proved difficult. As a result of extensive studies of the shell characters of species of known feeding types (by examinations of their radular teeth, gut contents, or feeding observations) I have chosen 3 characters that can be used to some degree for diagnosing feeding type. They are pink tip (PT) of the spire, tent marks (TM) on the body whorl (Plate 30, Figures A to D), and inter- rupted striae (IS) on the body whorl (Plate 30, Figures E to H). Analyses of these 3 characters in 55 species are shown in Table 2. It can be observed that none of the characters is exclusive to any of the feeding types. But they do show that each of the 3 characters is preponder- ant to one feeding type only. Graphic presentations illust- rated clearly that PT occurred in 100% of the piscivores, 44.4% in the molluscivores, and 5.6% in the vermivores considered (Figure 2). The TM character was present in Vv Figure 2 Graphic presentation of pink tip (PT) character in Conus shaded black. Vermivores (V) 5.6%; molluscivores (M) 44.4%; piscivores (P) 100% 100% of the molluscivores, 10% of the piscivores, and 2.7% of the vermivores considered (Figure 3). Thirdly, the IS character was positive in 100% of the piscivores, 13.9% of the vermivores, and totally absent in the mol- luscivores considered (Figure 4). From these analyses it may be concluded that TM is positively relevant to mol- luscivores and PT and IS are to piscivores; and that TM, PT, and IS are mostly negative to the vermivores. If these conclusions are to serve any useful purpose, these characters are examined closely in Table 2. It can be observed that all the piscivores considered have the combination of PT and IS characters, except Conus geo- Page 162 Figure 3 Graphic presentation of tent marks (TM) character in Conus shaded black. Vermivores (V) 2.7%; molluscivores (M) 100%; piscivores (P) 10% graphus, which has the characters of PT and TM. Conus geographus can easily be distinguished from all other spe- cies of Conus by its possession of a wide shell aperture. The transverse width of the aperture at the waist is more Vv Figure 4 Graphic presentation of interrupted striae (IS) character in Conus shaded black. Vermivores (V) 13.9%; molluscivores (M) 0%; piscivores (P) 100% THE VELIGER Vol. 12; No. 2 than twice that of the ventral body whorl at the same level (see Figure 5). Summarizing, the piscivores can be differentiated from either the vermivores or molluscivores by the following key. Figure 5 Measurement of transverse width of shell aperture (b) at the waist (x), and width of ventral body whorl (a) at same level KEY to PISCIVOROUS Conus (to be attempted on shells that are completely clean of periostracum ) 1. Transverse width of shell aperture at waist (see Figure 5)more than twice the transverse width of ventral body whorl at the same level. Shell spire with pink tip". Ae ee ee piscivore (part) — ‘Transverse width of shell aperture less than twice that of ventral body whorl at the same level. Shell spire with) or without pink tip) ieee cena eee 2 2. Body whorl of shell with transverse interrupted striae or striations on almost all its length; without tent MALKS hes ccstsntsecnaabeennren acacia ae 3) — Body whorl of shell without such markings; with tent marks molluscivore or vermivore (part) 3. Shell spire with pink tip piscivore (part) — Shell spire without pink tip vermivore (part) Explanation of Plate 30 The tent marks (TM) and interrupted striae (IS) characters on the body whorl of the shell in Conus. A: Conus amadis GMELIN, 1791; B: C. marmoreus LINNAEUS, 1758; C: C. aulicus LINNAEUS, 1758; (A to D: molluscivores) D: C. textile LinNaEus, 1758; E: C. tulipa LinnaEus, 1758; F: C. stercusmuscarum LINNAEUS, 1758; G: C. striatus LINNAEUS, 1758; H: C. magus LINNAEUS, 1758; (E to H: piscivores) [Lim] Plate 30 THE VELIGER, Vol. 12, No. 2 [FT FERS ay i i Alli ‘4 WA hety \\ \ wll. ial” ~~ Vol. 12; No. 2 THE VELIGER Page 163 Table 2 Shell markings of Conus species of known feeding type Reference to radular teeth/gut Species of Conus PT T™/ IS V M P contents/feeding observations 1. amadis GMELIN, 1791 — + — — + — Penne, 1939 2. ammuralis LINNAEUS, 1758 + + — — + — ENDeEaAN & Rupkxin, 1965 3. arenatus Hwass, 1792 — — + + — — ENDEAN & Rupkin, 1965 4. aulicus LINNAEus, 1758 — + — — + — EnpeEaN & Rupkin, 1965 5. betulinus LINNAEUS, 1758 —- — — + — — 6. californicus Hinps, 1844 — — — + — — WHYSNER & SAUNDERS, 1963 7. caracteristicus Fiscuer, 1807 — +-—- + — — 8. catus Hwass, 1792 + — + — — +. Koun, 1956 9. chaldeus Ropinc, 1798 — — — + — — Koun, 1959a 10. consors SowERBy, 1833 + — + — — + Lin, 1968 11. coronatus GMELIN, 1791 — — + + — — Koun, 1959b 12. dalli StEaRNS, 1873 — + — — + — Nysaxken, 1968 13. distans Hwass, 1792 — — — + — — Kosn, 1959a 14. ebraeus Linnaeus, 1758 — — — + — — Konn, 1959a 15. eburneus Hwass, 1792 — — — + — — Konn, 1959a 16. emaciatus REEVE, 1849 + ENDEAN & RupkiIn, 1965 17. figulinus LinnaEus, 1758 SS ae) KOHN, 1959)b 18. flavidus LAMarck, 1810 — — — + — — Koun, 1959a 19. geographus LinNaEus, 1758 + + — — — + Enpean « Rupxin, 1965 20. glans Hwass, 1792 + — — + — — Koun, 1959b 21. wnperialis LINNAEus, 1758 — — + + — — Konan, 1959a 22. leopardus Ropine, 1798 — + Koun, 1959 a 23. litteratus LinNAEus, 1758 — — — + — — EnpeAN « Rupkin, 1965 24. lividus Hwass, 1792 + — — + — — Koun, 1959b 25. luteus SowErsy, 1833 — — + + — — 26. magus Linnaeus, 1758 + — + — — + Enpean « Rupxin, 1965 27. maldivus Hwass, 1792 — — — + — — Pete, 1939 28. marmoreus LINNAEUS, 1758 — + — — + — Koun, 1959a 29. mediterraneus Hwass, 1792 — — — + — — Arprrs, 1932 30. miles LINNAEUS, 1758 —_—- — + — — Koun, 1959a 31. monachus LinNAEus, 1758 + — — — + 32. monile Hwass, 1792 — — — + — — Pete, 1939 33. moreleti Crosse, 1858 — — — + — — Koun, 1959a 34. musicus Hwass, 1792 — — + + — — Konn, 1959 a (as C. abbreviatus REEVE) 35. obscurus SowERBY, 1833 + — + — — + Koun, 1959a 36. omaria Hwass, 1792 + + — — + — _ EnNDEAN & Rupkin, 1965 37. pennaceus Born, 1778 + + — — + — Koun, 1959a 38. pertusus Hwass, 1792 — — — + — — Koun, 1959a 39. planorbis Born, 1780 — — — + — — ENpDEAN & Rupkin, 1965 40. pulicarius Hwass, 1792 — — — + — — Koun, 1959a 41. purpurascens SowERBy, 1833 > — + — — + Petre, 1939 42. quercinus LicHTFooT, 1786 SS Koei, IED a 43. rattus Hwass, 1792 — — — + — — Koun, 1959a 44. retifer MENKE, 1829 > + — — + — Koun, 1959a 45. sponsalis Hwass, 1792 — -— —— —«s*t — — Konwn, 19594 46. stercusmuscarum LinnaEus, 1758 + — + — — +. EnNpeaN & Rupkin, 1965 47. striatellus Linx, 1807 — — — + — — Prez, 1939 48. striatus LINNAEUS, 1758 + — + — — + Koun, 1959a 49. terebra Born, 1780 — — — + — — Koun, 1959b (as C. clavus LinNaEvus) 50. tessulatus Born, 1778 p= 51. textile LINNAEUuS, 1758 — + — — + — Konn, 1959b 52. tulipa LinNAEUus, 1758 + — + — — + Konn, 1963 53. vexillum GMELIN, 1791 — — — + — — Konan, 1959a 54. virgo LinnaEus, 1758 — — — + — — Konan, 1959b 55. vitulinus Hwass, 1792 — — — + — — Konun, 1959a IS = interrupted striae; M = molluscivore; P = piscivore; PT = pink tip; TM = tent marks; V = vermivore Page 164 THE VELIGER Vol. 12; No. 2 DISCUSSION The radular tooth characters previously described by ENDEAN & RupkKIN (1965) may be sufficiently diagnostic in determinations of feeding type. But this may not al- ways be convenient. It is considered that shell characters, if workable, would be preferable. Although the shell characters presented here cannot be used for determin- ing all 3 feeding types of Conus species, it may be employed to distinguish the piscivores from either the molluscivores or vermivores. It has already been known that the pisci- vores are the only species that may cause any serious danger to human beings (ENDEAN & RUDKIN, of. cit.). In this respect the proposed diagnosis by shell characters may be of interest. The analysis for the ratios among the 3 feeding types indicates clearly that the vermivores (65.46%) far out- number either the molluscivores (16.36%) or piscivores (18.18%). Studies of 50 species of Conus from Singapore and the Malay Peninsula revealed 38 (76%) to be vermi- vores, 7 (14%) molluscivores, and 5 (10%) piscivores (Lim «& Tan, in press). Comparing the ratios of feeding type in species from one area and that of feeding types in species from numerous areas combined show no highly marked differences. ACKNOWLEDGMENTS May I add an expression of thanks to Mr. A. J. Johnson and Mr. J. R. Fisher for kindly allowing me to examine their joint collection of cone shells. LITERATURE CITED ALPERS, FE 1932. Uber die Nahrungsaufnahme von Conus mediterraneus Brug., eines toxoglossen Prosobranchiers. Publ. Staz. Zool. Naples 11: 426 - 445 ENDEAN, Ropert & CLARE RUDKIN 1965. Further studies on the venoms of Conidae. 2: 225 - 249 Koun, ALAN JAcoss 1956. Piscivorous gastropods of the genus Conus. Proc. Natl. Acad. Sci. U.S.A. 42: 168 - 171 Toxicon 1959a. The ecology of Conus in Hawaii. Ecol. Monogr. 29: 47 - 90 1959b. Ecological notes on Conus (Mollusca:Gastropoda) in the Trincomalee region of Ceylon. (13) 2: 309 - 320 1963. | Venomous marine snails of the genus Conus. In: H. L. Kegcan & W. V. MacrarLane, ed., Venomous and poison- ous animals and noxious plants of the Pacific region. Pergamon Press, London, pp. 83 - 96 Lim, C. FE 1968. A comparative analysis of the feeding adaptations in the predatory gastropod Conus LINNAEUS. Third Europ. Mala- col. Congr. Vienna (abstract) Lim, C. EF « W.C. Tan (in press) Size and metabolic rate in the venomous snail Conus LINNAEUS. NyYBAKKEN, JAMES WILLARD 1968. Notes on the food of Conus dalli Stearns, 1873. The Veliger 11 (1) : 50 (1 July 1968) Ann. Mag. Nat. Hist. Pee, A. J. 1939. Radula notes, 8 Conus. Proc. Malacol. Soc. London 23: 348 - 355 Wuysner, J. A. & Paut R. SAUNDERS 1963. Studies on the venom of the marine snail Conus cali- Toxicon 1: 113 - 122 fornicus. Vol. 12; No. 2 THE VELIGER Page 165 Panamic Sites and Archaeological Mollusks of Lower California BY LAWRENCE H. FELDMAN Department of Anthropology, Pennsylvania State University, University Park, Pennsylvania 16802 (2 Tables) INTRODUCTION THIS PAPER IS AN ATTEMPT to systematically list all Lower California archaeological molluscan species from assemb- lages that are primarily Panamic in origin. Therefore the series of middens on the Pacific coast of the peninsula, north of Punta San Antonio, containing Californian faun- al province shells (c. f Moriarty, 1968a), are not men- tioned in this paper. Table 1 indicates what species are found at each site and Table 2 tries to show what the species tell us about the site occupations. On the basis of Table 2 we might divide the Panamic sites into two groups. A northern group is represented by the sites of Playa de Moreno, San Felipe and Bahia de los Angeles. These were inhabited only in the wet winter months; as for example at San Felipe, where the Kiliwa in historic times went to fish. “By summer, it was said, the fresh water at San Felipe was so dried up that no one lived there permanently. The indians gathered clams and mussels and caught fish and dried them in the sun to take back to their permanent rancherias,” (Meics, 1939: p. 27). It was only at sites of this part of Lower Califor- Table 1 Archaeological Mollusca PELECYPODA Pecten vogdesi ARNOLD, 1906 Dosinia ponderosa (Gray, 1838) Chione undatella (Sowersy, 1835) Pinna rugosa SowERBy, 1835 Cardita affinis Sowersy, 1833 Ostrea palmula CarPENTER, 1856 Anomia peruviana b’OrzIGNy, 1846 Anadara multicostata (SoweErRBy, 1833) Ostrea fisheri DAL, 1914 Pteria sterna (Goutp, 1851) Trachycardium panamense Dau, 1916 Laevicardium elatum (Sowersy, 1833) Chione gnidia (BropERIP & SoweErRBY, 1829) Chione fluctifraga (SowerBy, 1853) Spondylus princeps Broverip, 1833 Protothaca grata (Say, 1831) Tagelus californianus (Conran, 1837) Ostrea angelica RocHEBRUNE, 1895 Glycymeris gigantea (Reeve, 1843) Megapitaria squalida (Sowersy, 1835) SO He SOS CCAS sie Sik 3 il, 2, B C 1 x ls 2 il, 2 R SK 1 52 1 R A 1 1 A 1 1 52 1 1 A x 3 x 1 2 x 1 2 2 A il, 2 iP 2, 1 2 1 ?2 A A 33, 2 R P 2 C Page 166 THE VELIGER Vol. 12; No. 2 Table 1 [continued] Chama buddiana C. B. Apams, 1852 Chione cortezi (CARPENTER, 1864) Mulinia pallida (BropERip & SowERBY, 1829) Aequipecten tumbezensis (p’OrBIGNY, 1846) Mulinia coloradoensis Datu, 1894 Ostrea iridescens Hanuey, 1854 Trachycardium senticosum (SOWERBY, 1833) Semele flavescens (Goutp, 1851) Pinctada mazatlanica (HaNLEy, 1856) Arca pacifica (SowERBY, 1833) Barbatia reeveana (p’Orxicny, 1846) Anadara formosa (SowErRBY, 1833) Glycymeris maculata (BroperipP, 1832) Glycymeris multicostata (SOWERBY, 1833) Modiolus capax (Conrap, 1837) Aequipecten circularis (SowERBY, 1835) Lyropecten subnodosus (SoweErRBy, 1835) Trigoniocardia biangulata (BRoDERIP & SOWERBY, 1829) Periglypta multicosta (SowERBY, 1835) — GASTROPODA Haliotis sp. Bulla gouldiana Pirssry, 1895 Fusinus dupetitthouarsi (K1ENER, 1846) Hexaplex erythrostomus (Swainson, 1831) Crucibulum spinosum (SoweErsy, 1824) Conus regularis SowERBY, 1833 Strombus gracilior SowERBy, 1825 Turbo fluctuosus Woop, 1828 Tegula rugosa (A. ApaMs, 1855) Olivella biplicata (SowERBy, 1825) Polinices reclusianus (DESHAYES, 1839) Muricanthus nigritus (PHipri, 1845) Strombus galeatus Swainson, 1823 Conus fergusoni SowERBy, 1873 Oliva incrassata (LicHTFooT, 1786) Cerithium stercusmuscarum VALENCIENNES, 1833 Crepidula incurva (Broverip, 1834) Calyptraca mamillaris BRoDERIP, 1834 Crucibulum umbrella (DEsHaAyYES, 1830) Calyptraca subreflexa (CARPENTER, 1856) Nerita funiculata MENkE, 1851 Acmaea mitella MENKE, 1847 PM SF? SLG@ GC? BAS (S)iceesie 73) x x x 4 2, 2 2 5 1 C Cc R 1 R Cc 1 P R A P A R R 3 1 1 52 x ey 1 R 1 A 12 1 1 1 3 f 1 iP 2 1 A 2 Pp R 2 1 1 4 2 R x x x 2 2 ee 1 Playa de Moreno Beach, north of San Felipe. Collected by James R. Moriarty on October 31, 1958. Probably mixed with modern shell. 2 San Felipe. (1): ScHENck & GirForp, 1952. (2): Collected by James R. Moriarty from beach on October 31, 1958. Sample probably mixed with modem shell. (3): Clam shell from ex- tensive superficial midden on beach ridge, at edge of coastal terrace, just above aud W of air strip occupying a stranded lagoon, close to the San Felipe village well (31°01’N; 114°51’ W), Moriarty, 1968a. 3 San Luis Gonzaga Bay, Coan, 1965. (P) = present; (C) = common; (A) = abundant. 4 Gardner Cave, MeicHan, 1965. 5 Bahia de los Angeles. (1): E.L. Davis correspondence (July Vol. 12; No. 2 THE VELIGER Page 167 1965). (2): midden material collected by James R. Moriarty. (3): cave and midden material, Massey « Osporne, 1961. ® San José Island, Emerson, 1960. (R) = rare; (C) = com- mon; (A) = abundant. 7 San Lucas. (1): a 30mm diameter ring with a 10mm hole that was ground down and polished; collected by H.N. Lowe at Cape San Lucas and at present located in the San Diego Natur- al History Museum collections. (2): shells from terrace along nia that trade shells from other faunal provinces appear (1. e. Haliotis sp., Olivella biplicata). The San José Island site represents a possible southern group of summer occupation sites. Like the San Blas Nayarit shell middens, free swimming pectens are very Golfo de California at Punta Pescadero (23°47’06” N; 109°42’ 00” W), Mortarty, 1968. (3): Shell from shore of Ensenada de los Aripes, at Radio Station of La Paz, W of town proper, in indurated sand below high-tide level, and below level of adjacent midden (ca. 24°09’ N; ca. 110°19’30” W), Morrarty, 1968. (4): Punta Conejo, a shell mound about 40 miles N of La Paz and } to 4 mile inland from Punta Conejo on road to La Paz; collected by C. W. Meighan. (5): Cape San Lucas area shells, MAssEY « Osporne, 1961. abundant and suggest the presence of a deep water fishing industry (FELDMAN, n.d.). Perhaps a summer time sea salt production was also a factor in the occupation of the San José Island and San Blas sites at this season (c. f Moriarty, 1968b). Table 2 Archaeological Mollusca Sites Site® Radiocarbon Date® Species Niche’? —_ Seasonality" Playa de Moreno — ResiSc35 Bell ?winter only Podrs laisse || San Felipe (1) — IRe7/ 2 SoilOe Teil s winter only ?:1;R,S8:4 San Felipe (2) — RESIS es eos — R, S:1 San Felipe (3) 598 A. D. R:1 = San Luis Gonzaga = Rell e Seite winter & R, 8:2 summer Gardner Cave 1352 A.D. SeBo Peil — Bahia de los Angeles (1) — Reo SEOs Bele winter only PHO Sells lasyells S, B:2 Bahia de los Angeles (2) 4138 B. C. RESTS. ope Bel winter only 532 B.C. Pail Si asyell Bish} Bahia de los Angeles (3) — S45 FSslle Psi San José Island = Re Po Ge Teil ¢ summer only ?:6;R,S:4; FS:2 San Lucas (1) — R:1 — San Lucas (2) 263 A. D. R:1 8:2 — San Lucas (3) 1152 B.C. S:l a San Lucas (4) — S:1 — San Lucas (5) — eal ase 8 See footnotes of Table 1 for an explanation of site numbers. At B 9 Except for the Gardner Cave date, all Radiocarbon dates are FS = free swimming animal; ? = niche not known; from Moriarty, 1968. 'o Based upon data in Parker, 1964, and Kren, 1958: B = low-salinity lagoon and mangrove environment (brack- ish) ; S = intertidal sand beaches and sand flats to 26 meters 5 R = intertidal and shallow rocky shore assemblage; the numbers denote how many species are of each niche per site assemblage. Seasonality data, from Marxrin, 1962, are based upon recent collecting habits of the Seri Indians of Sonora for Gulf of California species. Page 168 THE VELIGER Vol. 12; No. 2 Panamic Lower California shows continuous exploita- tion of its molluscan resources from 6000 years ago up to the arrival of the European explorers. However, still little is known about the archaeological mollusks of most of the peninsula. Regions like the coast of the Bahia de Sebastian Vizcaino, where the Panamic fauna presumably grades into the Californian fauna and the peninsula from La Paz to Cabo San Lucas are almost totally unknown. Species lists from the middens of these and other Lower Californian areas might be of considerable interest for the light they could shed on the way of life of the aboriginal inhabitants of the peninsula. ACKNOWLEDGMENTS I would like to express my thanks to E. P. Chace, C. W. Meighan, J. R. Moriarty, and E. L. Davis for making available unpublished data on the archaeological shells of Lower California. LITERATURE CITED Coan, EucGENE VICTOR 1965. Kitchen midden mollusks of San Luis Gonzaga Bay. The Veliger 7 (4) : 216 - 218; plt. 28; 1 table (1 April 1965) EMERSON, WILLIAM KEITH 1960. Results of the Puritan-American Museum of Natural History Expedition to Western Mexico, 12: Shell middens of San José Island. Am. Mus. Novitates, No. 2013: 1-9, 4 figs. (18 August 1960) FELDMAN, LAWRENCE H. no date. | Greater Nayarit archaeological mollusks and archaeo- molluscan units in northern Mesoamerica. Paper prepared for inclusion in C. W. MEIcHAN’s monograph on the site of Amapa, Nayarit (12 December 1968) Keen, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford, Calif. (Stanford Univ. Press) Mackin, B. 1962. Seri Ethnozoology. 7: 1-56 Massey, WiiuiaM C. & CaRroLyn M. OssBorNE 1961. A burial cave in Baja California. The Palmer Collection, 1887. Univ. Calif. Anthrop. Records 16 (8) : 338 - 353 MEIGHAN, CLEMENT 1965. Cave paintings of Baja. Occ. Pap. Idaho State Coll. Mus. Desert 28 (7): 16-19 (July 1965) Meics, PEVERIL 1939. The Kiliwa Indians of Lower California. Americana 15. Univ. Calif. Press, Berkeley, Calif: Moriarty, JAMES ROBERT 1968a. Climatologic, ecologic and temporal inferences from ra- diocarbon dates on archaeological sites, Baja California, Mexico. Pacif. Coast Archaeol. Soc. Quart. 4 (1): 11-38 (January 1968) 1968b. The socio-political and economic influences related to the production and distribution of salt. Anthrop. Journ. Can. 6 (1): 2-15 Parker, Rosert H. 1964. | Zoogeography and ecology of some macro-invertebrates, particularly molluscs, in the Gulf of California and the conti- nental slope off Mexico. Vidensk. Medd. Dansk naturh. Foren. 126: 1 - 178; 15 plts.; 29 text figs.; 7 tables (17 Febr. ’64) ScuHEnck, W. EcBerT « E. W. Girrorp 1952... Archaeological sites on opposite shores of the Gulf of California. Am. Antiquity 17 (3): 265. (January 1952) Ibero- Vol. 12; No. 2 THE VELIGER Page 169 Cyclostrema miranda BARTSCH, a Synonym of Jornus subcarinatus MONTAGU DONALD R. MOORE Institute of Marine Sciences, University of Miami, Miami, Florida 33149 (3 Text figures) Paut BartscH, during the early years of the present century, described a large number of micromollusks from the Pacific coast of the United States. A number of these species were assigned to the Vitrinellidae although a mod- ern classification would put them in two orders and several families. One of the species described by Bartscu (1910) was Cyclostrema miranda, a small depressed gastropod about 2 mm in diameter. Since its description, it has not been reported from elsewhere on the Pacific coast since Datu (1921) and Keen (1937) both list it from only the type locality, San Pedro, California. In December, 1965, I examined the type specimens of west coast Vitrinellidae described by Bartsch. His Cyclos- trema miranda was of special interest since his illustration showed a shell with a very large oblique aperture. Typical Vitrinellidae do not have such a widely open aperture, although Macromphalina, a genus that does, has been placed in the family by some authors. When I examined the holotype of Cyclostrema miranda, I saw that it was a specimen of Tornus subcarinatus (Monrtacu, 1803). To make certain, I compared it with specimens in the JEFFREYS collection from Guernsey, one of the Channel Islands between England and France. This species is the type of the genus Jornus, and hence of the family Tornidae. It is thus of more than usual interest to those who work on minute mollusks. Tornus subcarina- tus is a European species ranging from Ireland and south- ern England (Forses & HANLEy, 1849), southward in the Atlantic to Senegal and Gabon (Nick és, 1950), and it is also found in the Mediterranean at least as far east as the Adriatic (Brusina, 1866). Now that the identity of the species is established, it would be of interest to know if it is actually living on the * Contribution No. 1085 from the Institute of Marine Sciences, University of Miami, Miami, Florida 33149 California coast. BartscH (1910) states that the type, and two other specimens in Mrs. Oldroyd’s collection, were collected by Mrs. Oldroyd at San Pedro, California. Ordinarily, this locality might be accepted at face value, but the lack of additional material, in a well collected area, is enough to instill doubt. Another incident that 4 Figures 1 to 3 Top, bottom, and lateral views of Tornus subcarinatus (after BARTSCH, 1910) may have some bearing on the case was the discovery of two specimens of Tornus subcarinatus in the Stimpson Collection at the University of Miami. The locality on the label was “Dry Tortugas,” a small group of islands near Key West, Florida. Charles T. Simpson was a scientific collector with a special interest in the Mollusca of Florida, and was a contemporary of Mrs. Oldroyd. It is possible that someone, through either duplicity or ignorance, gave or sold specimens to both collectors with false locality Page 170 THE VELIGER Vol. 12; Now 2 data. Tornus subcarinatus is a shallow water animal, and it is highly unlikely that it could be living on both sides of North America without being reported from more than a single locality. I personally have examined many shallow water bottom samples from the Florida Keys and adjoining areas without finding the species. The family Tornidae is equated with the Vitrinellidae by some workers, while others consider them to be distinct. I discussed this situation in 1965. My views have been modified slightly since some vitrinellids have a very long gill which protrudes a little beyond the edge of the aper- ture. However, it appears to be somewhat different from the gill of Tornus subcarinatus as figured by WoopwarpD (1899). The presence of a penis in vitrinellidae is based on observations by FRETTER (1956) on Czrculus striatus (Puiuippr) and by Moore (1964) on Parviturboides inter- ruptus (C.B. ApAMs). (Woopwarp (1899) did not find a penis in the male T: swbcarinatus that he examined. We still lack comparative data, but it does not appear that Tornus and the vitrinellids should be placed in the same family. One fundamental difference is the operculum, for even very depressed vitrinellids with a very oblique aper- ture, such as Cochliolepis parasitica Stimpson, have a circular multispiral operculum. Tornus subcarinatus, on the other hand, has an oval paucispiral operculum. Apparently, then, the Oldroyd and Simpson specimens of Tornus subcarinatus have spurious locality data and probably originally came from somewhere in the eastern hemisphere. There are apparently no congeneric species in the western hemisphere, but, until we know the fauna better, the presence of some member of the family cannot be ruled out. ACKNOWLEDGMENTS I am grateful to the Division of Mollusks, U.S. National Museum, for the opportunity to examine the type speci- mens of species described by Paul Bartsch. This work was supported by National Science Foundation Grants GB- 3104 (UM 8190) and GB-5055 (UM 8753). LITERATURE CITED BartscH, PauL 1910. Descriptions of new mollusks of the family Vitrinellidae from the west coast of America. Proc. U.S. Nat. Mus. 39 (1785) : 229 - 234; plts. 39, 40 Brusina, S. 1866. | Contribuzione della fauna dei molluschi dalmati. Soc. I. R. Zool. Bot. 17: 1- 134; 1 plt. Dati, WILLIAM HEALEY 1921. Summary of the marine shellbearing mollusks of the northwest coast of America, from San Diego, California, to the Polar Sea, mostly contained in the collection of the United States National Museum, Smithson. Inst., U.S. Nat. Mus. Bull. 112: 1-217; plts. 1-22 (24 February 1921) Forses, EpwarD & SYLVANUS HANLEY 1853. A history of British Mollusca, and their shells. Van Voorst, London. 2: 1-557 FRETTER, VERA 1956. The anatomy of the prosobranch Circulus striatus (PHIL- IpPi) and a review of its systematic position. Proc. Zool. Soc. London 126 (3) : 369 - 381; figs. 1-5 Keen, A. Myra 1937. An abridged checklist and bibliography of west North American marine mollusca. Stanford Univ. Press, Stanford, Calif., pp. 1 - 87 Moore, Dona.p R. 1964. The family Vitrinellidae in South Florida and the Gulf of Mexico. Ph. D. dissertation, Univ. Miami: 1 - 235; figs. 1-35 1965. New species of Vitrinellidae from Gulf of Mexico and adjacent waters. The Nautilus 78 (3): 73-79; 9 figs. Nick.es, M. 1950. | Mollusques testacés marins de la céte occidentale d’Af rique. Man. ouest-afric. 2: 1-269; figs. 1-459. Paris, Lechevalier. Woopwarpb, Martin FOUNTAIN 1899. On the anatomy of Adeorbis subcarinatus Montacu. Proc. Malacol. Soc. London 3: 140 - 146; plt. 8 Vol. 12; No. 2 THE VELIGER Page 171 Relative Growth Patterns of Two West Coast Squid (Gonatus fabric and Gonatopsis borealis) BY LARRY T. SPENCER Plymouth State College, Plymouth, New Hampshire 03264 (2 Text figures) INTRODUCTION THE OPTIMAL METHOD of determining patterns of growth in any organism is to maintain the species in a laboratory situation where measurements of size increases can be made throughout the lifetime of the individuals. For many organisms this task is quite impossible. Therefore measure- ments of relative growth are quite often used as substitutes. Although relative growth patterns do not indicate the time taken to attain maximum size, they are useful to compare the growth of two different species of squid. HarFner (1964)utilized the differences in growth pat- terns to taxonomically differentiate between Loligo pealei and Lolliguncula brevis in Chesapeake Bay, Maryland. This study presents the differences in relative growth of Gonatus fabric (LICHTENSTEIN, 1818) and Gonatopsis borealis Sasaxt, 1923, two pelagic squid species of the open ocean off Oregon. METHODS Eighty-one Gonatus fabricii and 88 Gonatopsis borealis were examined in detail. The specimens measured includ- ed those collected by the Department of Oceanography, Oregon State University and others loaned to the depart- ment by the U.S. Fish and Wildlife Service and the Uni- versity of Washington (Pearcy, 1965). Eight morpholog- ical characteristics were measured (these are described by Harrner, 1964): mantle width (MW); head width (HW); head length (HL); nuchal cartilage length (NCL); fin width (FW); fin length (FL); siphon width (SW) ; and siphon length (SL). ' This work was done as a Graduate Student in the Department of Zoology, Oregon State University, Corvallis, Oregon 97331 The relative growth patterns were determined as fol- lows: 1. The squid were grouped in 10mm intervals of dorsal mantle length. The average measurement for each of the 8 characters was calculated and in turn divided by the average dorsal mantle length for that interval. The resultant figure is defined as the morphometric index. 2. The indices for each size interval were plotted against average dorsal mantle length and the points were con- nected. The resultant curve is defined as the growth pattern. The curves for Gonatus fabricitt are more accurate in the lower size range (15 - 60mm) than in the higher size range (60 - 190mm) because of a lack of larger individ- uals. Comparable numbers of Gonatopsis borealis were measured in each size interval. RESULTS Gonatopsis borealis The relative growth patterns of Gonatopsis borealis are presented in Figure 1 (left). Two distinct patterns are readily discernible. One pattern is a rapid increase of the character size up to 30mm mantle size followed by either a plateauing (FL) or a continued peaking and then decrease (FW). The other pattern is a relatively rapid decrease of the character changing at 30mm mantle length to a less rapid decrease (MW, HW, HL, SW, SL, and NCL). Of the second group, mantle width exhibits the greatest decrease, whereas siphon length the least decrease, with the other characters intermediate. The less rapid decrease mentioned above is not a constant decrease as minor peaks are exhibited by head width at 40mm, 60mm, and 90mm; head length at 50mm; and nuchal cartilage at 90mm. Page 172 Fe) aS Morphometric Indices ° iS) ee 20 40 60 80 100 120 140 160 Dorsal Mantle Length THE VELIGER Vol. 12; No. 2 20 40 60 80 100 120 140 160 180 Dorsal Mantle Length Figure 1 Relative growth patterns of Gonatopsis borealis (left) and Gonatus fabricu (right). The scales at the right of each are only for fin width indices FL Fin Length FW Fin Width HL Head Length HW Head Width Gonatus fabrici The relative growth patterns of Gonatus fabriciu are presented in Figure 1 (right). The two general patterns observed for Gonatopsis borealis are also discernible for this species. All morphological characters except fin length exhibit growth curves that end at values lower than those of their starting points. Most curves (MW, HW, HL, SW, SL, and NCL) between 20 to 60mm mantle length show minor but progressively lower fluctuations. Fin width and fin length both show increases in the same interval, but the curve for fin length continues to rise attaining a peak at 143mm, and then decreases, whereas the curve for fin width reaches a peak at 30mm and decreases thereafter. DISCUSSION Generally speaking, with two exceptions, the growth pat- terns for Gonatopsis borealis and Gonatus fabricui are similar, showing higher values in the smaller squid and lower values in the larger squid. As the curves are of the relative growth patterns (i. e., growth with respect to the NCL Nuchal Cartilage Length MW Mantle Width SL Siphon Length SW _ Siphon Width dorsal mantle length), this indicates that the mantle length increases at rates greater than those of the other measure- ments. As larval squid often have a truncated, broad mantle and the mantle length: width ratios increase with age, these patterns should be expected. The two exceptions mentioned above are in fin width and fin length. Both Gonatopsis borealis and Gonatus fab- ric show large increases in the rate of growth for fin length, but the rate of growth for the former reaches a plateau after peaking at 30mm mantle length, whereas the growth of the fin length of the latter continues to rise, reaching a peak at 143mm mantle length. In the rate of growth for fin width, Gonatopsis borealis exhibits rapid growth, peaking at 50 mm mantle length, remaining steady for another 40 mm of mantle length, then decreasing there- after. The growth curve for fin width in Gonatus fabricu increases rapidly to a peak at 30mm mantle length, but then decreases throughout the rest of the curve. The differences in fin morphology can be seen also in Figure 2. I believe the above differences in the morphology of the fins are indicative of a functional difference between the two squid species. WILLIAMSON (1965) concluded from Vol. 12; No. 2 observations made on Illex ilecebrosus that the fins served to steer the squid and that, as the density of the squid exceeded that of the water, they may also have served to create a lifting force. Similar observations are mentioned by Lane (1960) and Morton (1964). If the area of the fin is related to lift (i. e., the larger surface area provides greater lift when moving at slow speeds) then Gonatopsis borealis (fin area = 478 mm?’ for dorsal mantle length of Figure 2 External morphology of Gonatus fabricti (left) (217mm _ dorsal mantle length) and Gonatopsis borealis (right) (210mm dorsal mantle length) 210mm) would be more efficient than Gonatus fabricu (fin area — 306mm? for a dorsal mantle length of 217 mm). The fin of Gonatopsis borealis is also stronger than that of Gonatus fabrici, if greater fin thickness is indica- tive of greater muscular strength. Non-quantified obser- vations made during this study showed that there was a difference in the thickness of the fins of the two squid species. THE VELIGER Page 173 From the differences shown by the relative growth patterns and by the gross external differences it appears that the fins of Gonatapsis borealis play a much greater role in the maintenance of vertical position and in loco- motion at slow speeds than do those of Gonatus fabricii. Although both squids are good swimmers, the former should be more active than the latter in maintaining its vertical position. The relative growth patterns obtained in this study are very similar to those calculated by HAEFNER (1964). HAEFNER used the information from his morphometric study as a means of taxonomically differentiating between Loligo peale: and Lolliguncula brevis. He noted that the main difference in the growth patterns of the two species was in the fin width and length indices. Although he did not reach any conclusions concerning the locomotion of the two species, it seems as if functional differences hypo- thesized in this study might also be applicable there. ACKNOWLEDGMENTS This work was done as a graduate student at Oregon State University. I would like to thank Dr. Ivan Pratt of the Department of Zoology for his assistance and for the lab- oratory facilities. I would especially like to thank Dr. William G. Pearcy, Department of Oceanography, for the use of his laboratory facilities and for his suggestions concerning this paper. LITERATURE CITED Haerner, Paut A,, Jr. 1964. | Morphometry of the common Atlantic squid Loligo pealei, and the brief squid, Lolliguncula brevis, in Delaware Bay. Chesapeake Sci. 5: 138 - 144 Lane, FRANK WALTER 1960. Kingdom of the Octopus. York, N. Y.; 432 pp. Morton, Joun Epwarp 1958. Molluscs: An introduction to their form and functions. New York, Harper Bros. 232 pp.; 23 text figs. Pearcy, WILLIAM GORDON Sheridan House, New 1965. | Species composition and distribution of pelagic cephalo- pods from the Pacific Ocean off Oregon. Pacif. Sci. 14: 261 - 266 WILLIAMSON, G. R. 1965. Underwater observations of the squid Illex illecebrosus Lesueur in Newfoundland waters. Canad. Field-Natur. 79: 239 - 246 Page 174 THE VELIGER Vol. 12; No. 2 Occurrence of the Sacoglossan Opisthobranch Hermaea dendritica ALDER & Hancock in New England BY KERRY B. CLARK AND DAVID R. FRANZ University of Connecticut Marine Research Laboratory, Noank, Connecticut 06320 THE PUBLISHED RECORDS of Sacoglossa from New Eng- land include only six species: Elysia chlorotica (GouLp, 1870), Elysia catula (Gou.p, 1870), Alderia harvardiensis GouLp, 1870 — considered to be synonymous with Alderia modesta (LovEéN, 1844) (Hanp & STEINBERG, 1955; BLEAK- NEY & BaiLey, 1967) — Stiliger fuscatus (GouLp, 1870), Limapontia zonata (Grrarp, 1852), and Hermaea cruci- ata Goutp, 1870. Of these, the latter 2 species have not been reported since their original descriptions. Thus, a new record would be the first addition to the fauna in nearly 100 years. Hermaea dendritica ALDER & Hancock, 1855, a species occurring in Britain and Norway (Sars, 1878), the Medi- terranean, and Japan (Marcus, 1961), has twice previ- ously been reported from the western Atlantic. Marcus (1961) reported the species from North Carolina, and cited a manuscript by the late Dr. George Moore, noting the occurrence of Hermaea dendritica in New England. However, no description or analysis was given. An established, breeding population of Hermaea dend- ritica has been discovered near the Marine Research Laboratory of the University of Connecticut, at Noank, Connecticut, from which specimens have been collected in May, 1967, and June to September, 1968. The specimens agree closely with the description and figures of ALDER & ' Contribution No. 52 of the Marine Research Laboratory, Uni- versity of Connecticut, Noank, Connecticut 06320. Hancock (1846). Body color is cream-white or greenish, with the liver ramifications visible through the body wall as dark green or brown dendritic markings. The genital opening is triaulic, and the albumen glands extend into the cerata. There are from 18 to 65 smooth, club-shaped cerata arranged in a double dorso-lateral row on each side. The radula appears to be identical with that figured by ALDER & Hancock (1846) and Bercu (1886). Adults measuring 4 to 8mm in length have been collected from the alga Codium fragile (SuRINGER) Hart- oT 1867, which has only recently established itself in New England. The Codium bed from which the specimens were collected is located on a shell bottom in about 2.5 m of water, at a salinity of about 30%,. Adults and egg masses occur only on the upper, actively growing portions of the algae. The egg masses contain 80 - 130 eggs measuring ap- proximately 70 4, arranged in a broad flat coil of 1 - 14 turns, the entire mass measuring 1.0 to 1.6mm in dia- meter. Hermaea dendritica must be compared with two other western Atlantic species, H. coitrala Marcus, 1961, from Brazil (Marcus, 1961) and H. cruciata Goutp, 1870, from Naushon Island, Massachusetts (Gouin, 1870). Hermaea cruciata was briefly described by Goutp from a sketch provided by Alexander Agassiz. No type specimen of the species exists. ‘The sketch closely resembles. Marcus’ drawing of H. coirala. Both species differ from H. dendri- tica in the following ways: the cerata are distally inflated, Vol. 12; No. 2 with branching of the liver tubules at the tips, while those of H. dentritica are of uniform thickness and the liver tubules do not branch. The bodies of H. coirala and H. cruciata are only half as broad as that of H. dendritica. The oral veil of both species is markedly different, with the anterior margin of the foot divided by a short groove lacking in H. dendritica, and the cerata of H. coirala and H. cruciata are arranged in two single rows. Hermaea coirala’s rhinophores are distally bifid, but this feature cannot be discerned from Agassiz’ sketch of H. cruciata. Two factors imply that Hermaea dendritica has only recently become established in the New England region. First, as indicated by Gonor (1961), sacoglossans are highly selective feeders, being restricted to one or a few species of algae. Hence, it is highly unlikely that H. dend- ritica could survive in New England until its food species, Codium, had itself become established. Second, sampling of many Codium beds in Eastern Connecticut has failed to locate another population of the animal, a situation to be expected where an organism has newly extended its range. THE VELIGER Page 175 LITERATURE CITED ALDER, JosHuA & ALBANY Hancock 1846. A monograph of the British nudibranchiate Mollusca. Ray Soc., London Bercu, Lupwic SopHus Rupo.tpH 1886. Beitraége zur Kenntniss der Aeolidaden, VIII. Verh. Zool.-Bot. Gesellsch. Wien 35: 1 - 60 BLEAKNEY, J.S. & KANIAULONO BaILEy 1967. Rediscovery of the salt-marsh sacoglossan Alderia mo- desta LovéN in eastern Canada. Proc. Malacol. Soc. Lon- don 37: 347 - 349 Goutp, Aucustus ADDISON 1870. | Report on the Invertebrata of Massachusetts. (Mollusca, W. G. Binney). Boston Hanp, Capet & JOAN STEINBERG 1955. On the occurrence of the nudibranch Alderia modesta Loven on the central Californian coast. The Nautilus 69 (1): 22-28 Marcus, ERNST 1961. | Opisthobranchia from North Carolina. Elisha Mitchell Sci. Soc. 77 (2): 141-151 Sars, G. O. 1878. _ Bidrag til kundskaben om norges Arktiske fauna: I. Mollusca regionis Arcticae Norvegicae. i- xii+466 pp., 34 +XVIII plts. Christiania 2nd ed, Journ. Page 176 THE VELIGER Vol. 12; No. 2 Observations on the Tentacles of Vaginulus borellianus Couosi (Mollusca : Gastropoda : Soleolifera ) BY ARISTEO RENZONI Istituto di Zoologia, Universita di Siena, Italia (Plates 31 to 35; 3 Tables) INTRODUCTION THE TENTACLES OF GASTROPODS, like other organs of these animals and of other metazoans, are able to regenerate. In fact, it is quite certain that most of the deformities of these cephalic structures are due to abnormal regeneration following loss of or damage to tentacles. The first descrip- tion we have of the phenomena of regeneration in mol- lusks is that of SPALLANZANI (1768). Subsequently the subject was taken up by various researchers (WarRTEL, 1768, ScHAFFER, 1768, MULLER, 1778, etc.) and analyzed in great detail by Moguin-Tanpon (1851), who, in his studies on Helix nemoralis, discovered that the regenera- tion of the anterior portion of the head occurs only when the cerebral ganglia remain intact. This finding explained the seeming contradictions of previous researchers who had cut off the tentacle or head at different levels. Moguin-Tanpon’s results were confirmed by subsequent studies on other gastropods (CarrizRE, 1880; CERNy, 1907; Konic, 1915). Nonne (1925) denies the importance of the central nervous system in the regeneration of certain parts of the tentacle, in particular the eye. ABELOOS (1942) maintains that the regeneration of all cephalic organs of gastropods is controlled by “a specific part of the tegmentum.” After numerous histological and histo- chemical studies of regenerating tentacles of Arion rufus and Agriolimax agrestis, CHETAIL (1957, 1963) concludes that after the removal of the tentacle a regeneration blas- tema develops where the tentacle was amputated. It con- sists of an exoblastema and an endoblastema, distinguish- able by their different origins, histochemical character- istics and systems of cellular reproduction. None of the above mentioned authors has looked into possible effects of the tentacles on the development or functioning of the gonads. On the other hand, PELLUET & Lane (1961) cut off the tentacles of Arion and Helix with the main purpose of analyzing the effect on the gonads. Among other interesting findings, they observed that the optic nerve clearly regenerates after 3 to 4 weeks, and that, when only the optic and tentacular nerves are severed, a great accumulation of secretion can be found in the cytoplasm of the “collar cells” of the tentacles. My experiments with the amputation of tentacles were carried out with the following purposes in mind: 1) To see whether regeneration occurs in Vaginulus borellianus, and, if so, to analyse the phases and manner of this process as well as the structure and the ultrastructure of the regenerated organ; 2) To investigate the possible relationship between the tentacle components (more precisely, their glandular and neuroglandular elements) on the one hand and the devel- opment of the gonads on the other. Explanation of Plate 31 A) Dorsal section of the cephalic region of a normal animal. The optic tentacles are retracted. 18 D) Same as Figure C. yi = Be PC = perigangliar cells X75 OE B) Sagittal section of an optic tentacle of a normal animal. C) Distal end of the tentacular nerve. X30 x36 olfactory epithelium TN = tentacular nerve THE VELIGER, Vol. 12, No. 2 [Renzon1] Plate 31 Vol. 12; No. 2 THE VELIGER Page 177 MATERIALS ann METHODS Specimens of Vaginulus borellianus were obtained from the Istituto di Zoologia, Universita di Firenze, about 3 years ago. They were kept in our laboratory in small plastic boxes where they reproduced several times. Their diet was lettuce, carrots, and slivers of fruit. For histo- logical and histochemical studies the tentacles (both nor- mal and regenerated) were fixed in Bouin’s fluid, neutral 10% formaldehyde or Susa’s fluid, dehydrated, embedded in paraffin and sectioned, using the usual procedures. The sections were stained with Mayer’s hemalum and eosin, Heidenhain’s hematoxylin, PAS reaction (McManus), and a modification of Bodian’s protargol-silver nitrate method. For electron microscopy small pieces of normal and regenerating tentacles were fixed in 3% glutaralde- hyde in a 7.2 phosphate buffer, post-fixed in 1% osmium tetroxide in a 7.2 buffer and embedded in Araldite. The blocks were sectioned with an L. K. B. ultratome and the sections examined in an Elmiskop I A electron microscope after staining with uranyl acetate and lead citrate. EXPERIMENTS The following experiments were made: A) amputation of the right optic tentacle of 10 10-day old specimens; B) amputation of the right optic tentacle of 8 6-month old specimens ; C) amputation of both upper tentacles of 6 10-day old specimens ; D) amputation of the lower tentacles of 6 10-day old specimens ; E) amputation of the upper tentacles of 8 10-day old specimens followed by amputation of the regen- eration blastema every 2 weeks over a period of 6 months; F) amputation of both optic tentacles of 6 3-month old specimens. The tentacles were cut off under a binocular microscope using partially anesthetized specimens with fully distended tentacles. The regeneration blastema and control tentacles were measured under the same conditions. In experiments A and B, the left tentacle was considered the control tentacle; for the other experiments 6 specimens of the same age were used as controls. OBSERVATIONS Experiment A: The specimens were examined and meas- ured 10, 30, 60, and 90 days after the amputation. The measurements of the control tentacle, the regenerative blastema and the regenerated tentacles thus obtained are given in Table 1. It can be seen that regeneration occurs at an even pace during the entire period of observation. Two other facts seem equally noteworthy, namely that by the 10" day, with the first phase of cicatrization completed, the regeneration blastema is already evident and meas- urable, and that some time between the 60" and 90" day after the amputation, the regenerated tentacle has grown to, or almost to, the length of the control tentacle. A most interesting detail was found in one specimen of this group. Serial sections showed that the regenerated nerve consisted not of a single strand, as in the other regenerated tentacles and the normal ones (Plate 31), but of 3 (Plate 32, Figure E), and that, at the tip of the tentacle they end in the tentacular ganglion. Experiment B: In this case too, all specimens were exam- ined 10, 30, 60, and 90 days after the amputation; the results are given in Table 2. Here, too, the rhythm of re- generation is quite regular, and the regenerated tentacles grow to the length of the controls within 90 to 100 days. Experiment C: The specimens used in this experiment were sacrificed at the age of 6 months and measurements were made of the regenerated tentacles as well as the hermaphrodite glands. Tentacles and hermaphrodite glands of control specimens were also measured (see Table 3). Experiment D: In this case the specimens were examined Table 1 Regenerative Capacity of Tentacles of Vaginulus borellianus Mean length in mm +standard error L=length of left tentacle R = length of right tentacle before and after amputation ( | ) Age in Days 10 20 30 40 70 100 L 2.07 +0.12 2.34+0.17 2.96 +0.14 4.27 £0.37 6.11+0.71 Weis 2040 R 2.01 +0.27 0.53+0.17 2.94 + 0.24 5.39+0.41 7.31+0.16 1.87 £0.09 Page 178 THE VELIGER Vol. 12; No. 2 Table 2 Regenerative Capacity of Tentacles of Vaginulus borellianus Mean length in mm =standard error L=length of left tentacle R = length of right tentacle before and after amputation ( | ) Age in Days 180 | 190 200 210 240 270 L 9.32 +£0.41 9.57 +£0.17 9.66 + 0.44 9.77 +£0.32 9.79 £0.22 9.80+0.21 R 9.47 £0.37 1.11+0.07 3.27+0.16 6.12 +0.37 8.96 £0.21 9.57 £0.39 Table 3 Weight of the body (b) ; mean weigth of the ovotestis (ot) (in gr) and number of eggs (ne) in the ovotestis after amputation of optic tentacles (O) or inferior tentacles (1) or repeated amputation of the optic tentacles every 15 days (OO). C=Control individuals Age in Days 10 30 60 90 120 150 180 O 0.094 0.201 0.473 1.023 2.633 4.300 5.98 +0.64 (b) 0.0246 + 0.0047 (ot) 130:0 =+1.98 (ne) I 0.095 0.221 0.463 1.050 2.666 4.500 6.06 +0.77 (b) 0.0261 +0.0061 (ot) WAS) sey (in) OO 6.02 +0.49 (b) 0.0266 +0.0069 (ot) 28° Oe =17/7ieen (Ke) Cc 0.066 0.202 0.471 1.039 2.550 4.450 3:83 027/ (by) 0.0288 + 0.0052 (ot) 133.0 +2.10 (ne) Explanation of Plate 32 A) Section of a regenerating optic tentacle. X18 E) Dorsal section of a regenerating optic tentacle (Experiment A). B) Same as Figure A at higher magnification. Note the numerous iihrce branches of the tentaculan TEtVe: zx 18 PEA he 60 F) Cross section of a regenerating tentacle (Experiment E). Arrows Dee oe point to 4 branches of the tentacular nerve. 100 C) Perigangliar cells in a regenerating optic tentacle. 100 1 eidendnte GOS = gland of Semper’s organ D) Regenerated lower tentacle. Layer of “Spindelzellen” (arrow) OE = olfactory epithelium PC = perigangliar cells and gland of Semper’s organ. X 36 SpC = spindelzellen TN = tentacular nerve Explanation of Plate 33 Section of the distal portion of the olfactory epithelium of a normal tentacle. X 30000 CG = cila D = dendrite M = mitochondria ML = layer of mucus MV = microvilli PP = plasmatic processes SC = sustentacular cells SeC = sensory cells [ReNnzon1] Plate 32 THE VELIGER, Vol. 12, No. 2 [RENzoNI] Plate 33 Tue VELIGER, Vol. 12, No. 2 Vol. 12; No. 2 THE VELIGER Page 179 90 days after the amputation of the tentacles, at which time the regenerated tentacles were of almost the same length (5.94 mm) as those of the control specimens (6.05 mm). For the other results see Table 3 and Plate 32, Figure D. Experiment E: This experiment, in which the regenera- tion blastema was re-amputated every 15 days, was de- signed to eliminate any possible influence that the regen- erating tentacle might have on the gonads. The blastema developed again each time and the animal appeared to be normal throughout the experiment. The results obtained from 6 specimens are reported in Table 3. The other 2 specimens were kept alive for another 90 days after the final amputation. By then the regenerated tentacles had almost reached the length of those of the controls. In these 2 specimens the outward appearance of the regenerated structure was variable; in general its diameter was greater all along the tentacle and in particular at the tip, and almost all the regenerated portions were colorless. Histo- logical examination showed an almost total absence of pigment cells in the epithelial and sub-epithelial layers. In 2 specimens of this group the regenerated tentacular nerves consisted not of a single strand, but of 4 to 5 branches (Plate 32, Figure F), closely resembling the unusual specimen of group A. Since the material that was fixed did not include the cerebral ganglia, I was not able to trace these strands to their origin. However, we may suppose that the branching of the tentacular nerve occurs somewhere close to the cerebral ganglia. Experiment F: The 6 individuals used in this experiment were sacrificed 5, 15, 30, 60, 90, and 120 days after the amputation of the tentacles, respectively. This was in or- der to follow the stages in the differentiation of the various components of the tentacles, as was recently done with normal tentacles (RENZONI, 1968). The following outline of events can be presented: Until the 6" day, scar formation takes place with the typical phenomena of pycnosis and the presence of numer- ous macrophages of various sizes. From the 7" to the 15" day, there is a period of latency during which the appearance of the exoblastema and endoblastema (typical regenerative processes) is clearly seen. From the 15" to the 40"™ day there is marked activity of the components of the regenerating blastema. The large number of different-sized nuclei indicates the presence of the various cell populations. Mitotic figures are frequent in the exoblastema, but rare in the endoblastema. Isolated macrophages can still be found. Between the 40" and the 90" to 100" day a gradual return to normalcy takes place, following the differentia- tion of the exo- and endoblastema into the various cell types (Plate 32, Figures A, B) typical of the normal ten- tacle: those of the distal sensory epithelium, of the tenta- cular ganglion, the periganglion cells (Plate 32, Figure C) (RENzONI, 1968), the “Spindelzellen” underneath the epithelium (Plate 32, Figure B), the dermo-muscular components, and the pigment cells branching among the epithelial cells. No instance of eye regeneration was found in this or any of the other experiments. Some of the specimens were observed directly under the dissecting microscope, but most of them were sectioned serially. Neither method showed any traces of eye formation, not even an invagi- nation of the exoblastema that would have suggested a possible retarded development of this organ. In fact, several individuals from experiment A were kept alive for more than a year and the eye still did not develop. Regarding the ultrastructure of the components of the tip of the regenerated tentacles, although no substantial differences appear in the animals of experiments A and B, they do appear in those of group E. The external appear- ance and structure of the regenerated tentacle of animals from this group showed considerable variation, and these morphological changes were confirmed at the electron- microscope, especially at the level of the sensory epi- thelium. In fact, whereas the epithelium of the proximal and medial portions of the tentacle, the “Spindelzellen” and the few “collar cells” do not differ appreciably from those of the normal tentacle, the cells that constitute the olfactory epithelium are so changed (see Plates 33 and 34) that only by careful examination can one distinguish the 3 cell types found in the sensory epithelium of normal specimens (see RENZONI, 1968). ‘The sensory and the sup- porting cells are particularly altered: in the former, the the cytoplasm and ciliary apparatus are most changed; in the latter, the apical microvillar processes (Plate 34; Plate 35, Figure A). The paucity of organelles (except for the still numerous mitochondria) gives the cytoplasm of the sensory cells the appearance of homogeneously low elect- ron density. Some of the mitochondria are of the same size as those found in the same elements of the normal tentacle, some are much larger; however, at least with the magnification used in this study, their structure does not differ appreciably from that of the others. The microtu- bules, which are especially numerous and evenly distrib- uted in the sensory cells of the normal tentacle, are less numerous and sometimes isolated and sometimes in clus- ters (Plate 35, Figure C) in the regenerated tentacle. Although the cilia at the apex of the dendrite have the typical 9+2 pattern, their number varies considerably from cell to cell. The microvilli also appear to be reduced in number. The cytoplasm of the supporting cells is not Page 180 THE VELIGER Vol. 12; No. 2 noticeably changed, whereas the dense-cored filament of the large microvillar processes of these elements under- goes varying modifications (Plate 35, Figure D) ; in some processes it is altogether lacking, in others it is present and resembles normal ones, and in still others it is present, but it is much larger than normal and of very high electron density. Distally, the processes still have the tendency to branch (Plate 35, Figure A) as in the normal tentacle, and, furthermore, they seem to extend outwards to the layer of mucus (usually covering the external surface of the tentacles) with various projections of different sizes and shapes (Plate 35, Figure A). DISCUSSION The process of regeneration of amputated tentacles (optic and lower) in Vaginulus borellianus is substantially the same as that described in the numerous studies on other pulmonates. The weights of the body and ovotestis and the number of eggs in the ovotestis of experimental animals (experiments C, D, E) show no significant variations either in compari- son with each other or with the control animals. This is in clear contrast with the results of PELLUET & LANE (1961) in other pulmonates (Helix and Arion). These authors find marked changes in the hermaphrodite gland after the removal of tentacles and attribute them to the absence of certain tentacular cells described as neurosec- retory (hormonal). Morphologically similar cells, differ- ing only in a few cytochemical and ultrastructural charac- teristics, are also found in the periganglionic area of tentacles of Vaginulus (RENZONI, 1968). Regarding both structure and ultrastructure, whereas the sensory cells in tentacles that have regenerated after a single amputation do not differ appreciably from the con- trols, those in tentacles that have regenerated after re- peated amputations of the regenrative blastema are con- siderably altered, especially at their apical end. Since, as far as I can find, this is the first recorded instance of such alterations, any hypothesis is risky, although it seems clear that with the repetition of the trauma the nervous ele- ments suffer most. The pigment cells are greatly dimin- ished in experiment E, whereas the “Spindelzellen” do not show appreciable differences. In contrast with the results obtained by other authors on different species, in our specimens of Vaginulus, whether the tentacles were cut off once or the blastema was cut off repeatedly, the eye consistently did not regenerate. The results of the many studies of regeneration of organs and structures in the cephalic region of mollusks, have always shown discrepancies, sometimes because of the differences in the species examined and other times because of mis- taken interpretations. Nevertheless, the tendency has been to attribute variations in regeneration to greater or lesser damages suffered by the cerebral ganglia. In our study, only the tentacles or regenerating blastema were cut off, so that the eye’s incapacity to regenerate cannot be attrib- uted to the removal of tissue from the cerebral ganglia. For the present we are at a loss for an explanation of this phenomenon; there is no doubt, however, that the non- regeneration of the eye is further evidence that single or Explanation of Plate 34 Distal portion of the olfactory epithelium of a regenerating tentacle (Experiment E). 30000 ML = layer of mucus Explanation of Plate 35 A) Same as the Figure of Plate 34. Note the distal branching of the processes of the sustentacular cells. X 30000 B) Cross section of a dendrite of a sensory cell bearing cilia and some microvilli. Regenerating tentacle. 30000 C) Cross section of a regenerating tentacle; microtubules in a dendrite of a sensory cell. XX 30000 D) Cross section of the distal portion of a regenerating tentacle, Where typical microvilli and a few plasmatic processes are clearly evident. 30000 C = cilia ML = layer of mucus MT = microtubules MV = microvilli PP = plasmatic processes SC = sustentacular cells THE VELIGER, Vol. 12, No. 2 [RENzonI] Plate 34 [RENzon1] Plate 35 THE VELIGER, Vol. 12, No. 2 Vol. 12; No. 2 THE VELIGER Page 181 multiple amputations of the tentacle cause striking alter- ations in components of the nervous system: branching of the tentacle nerve, modification of the sensory cells, non- regeneration of the eye. SUMMARY The author has conducted several experiments with the amputation of the tentacles of Vaginulus borellianus (Gastropoda Soleolifera) with the following purposes in mind: a) To see whether the regeneration occurs in this species and if so, to analyse the phases and manner of this process as well as the structure and ultrastructure of the regener- ated organ; b)to investigate the possible relationship between the tentacle components (more precisely, their glandular and neuroglandular components) on the one hand and the development of the gonads on the other. The following results have been obtained: 1) The process of regeneration on amputated tentacles (optic and lower) in Vaginulus is substantially the same as that described in the numerous studies of other pulmo- nates. 2) The weights of the body and ovotestis and the number of eggs in the ovotestis of experimental animals (experi- ments C, D, E) show no significant variations either in comparison with each other or with the control animals. 3) Regarding both structure and ultrastructure, whereas the sensory cells in tentacles that have regenerated after a single amputation do not differ appreciably from the con- trols, those in tentacles that have regenerated after re- peated amputations of regenerative blastema are con- siderably altered, especially at their apical end. 4) The eye consistently did not regenerate in any of the experimental animals (whether the tentacles were cut off once or the blastema was cut off repeatedly). LITERATURE CITED Carriere, J. 1880. Studien tiber die Regenerationserscheinungen bei den Wirbellosen. 1) Die Regeneration bei den Pulmonaten. Wirzburg: 4-56 (as quoted by Cueralz) Cerny, A. 1907. Versuche tiber Regeneration bei SiiBwasser- und Nackt- schnecken. Arch. Entw. Mech. 23: 389 - 392 Cuneta, M. 1956. Caractéres histologiques du blastéme de régénération tentaculaire chez Arion rufus L. Compt. Rend. Acad. Sci. 242: 1655 - 1656 1958. Action du bleu trypan sur le blasttme de régénération tentaculaire d’Arion rufus L. Compt. Rend. Acad. Sci. 246: 642 - 644 1963. Etude de la régénération tu tentacule oculaire chez un arionidae (Arion rufus L.) et un limacidae (Agriolimax ag- restis L.). Ph. D. thesis, Facul. Sci. Univ. Paris. Masson & Co., Publ. Isserorr, H. 1964. Fine structure of the eye spot in the miracidium of Philophthalmus megalurus. Journ. Parasit. 50 (4) : 549-554 Kernels, A. 1968. Nouvelles données histochimiques et ultrastructurales sur les photorécepteurs “branchiaux” des Dasychone bombys (DaLyELL) ; Annélide Polychéte. Zeitschr. Zellforsch. 86: 280 - 292 Konic, E. 1915. Die Regeneration des Auges bei Avion empiricorum. Arch. Mikr. Anat. 80: 293 - 317 Mogurn-Tanpon, A. 1851. | Mémoire sur lorgane de l’odorat chez les Gastéropodes terrestres et fluviatiles. Ann. Sci. nat. Zool. 15: 151 - 158 MULLER, M. 1778. Sur la reproduction des parties et nommément de la téte des limagons a coquille. Journ. Phys. 12: 111 - 118 Nakamura, A. 1967. Electron microscopy on the ceras of an opisthobranch, Godiva ceylonica, with special reference to muscles. Biol. Journ. Okayama Univ. 13: 97 - 113 Nonneg, FE. 1925. | Versuche uber den Einflu8 des Nervensystems auf die Regeneration der Augen von Pulmonaten. Arch. Entwickl. Mech. 105: 430 - 469 PELLUuET, D. « N. Lane 1961. The relation between neurosecretion and cell differen- tiation in the ovotestis of a slug. Gastropoda: Pulmonata. Canad. Journ. Zool. 39: 789 - 805 RENZONI, ARISTEO 1968. | Osservazioni istologiche, istochimiche ed ultrastrutturali sui tentacoli di Vaginulus borellianus (Colosi) ; Gastropoda: Soleolifera. Zeitschr. Zellforsch. 87: 350 - 376 1968. Olfactory epithelium of gastropods. In: Electron Microscopy (4 Europ. Region. Conf.) 2: 567 - 568. D. Steve Bocciarelli, Ed. ScuHArrer, M. 1768. | Versuche tiber die Reproduktion der Schnecken. Regensburg. SPALLANZANI, L. 1768. Prodromo di un’opera ad imprimersi sopra la ripro- ductioni animali. Modena Tonosaki, A. 1967. Fine structure of the retina in Haliotis discus. Zeit- schr. Zellforsch. 79: 469 - 480 WartEL, C. 1768. | Mémoire sur les limagons terrestres de l’Artois pour servir 4 l’histoire naturelle de cette province. Arras Page 182 THE VELIGER Vol. 12; No. 2 Marine Fouling and Boring Organisms in Monterey Harbor II. Second Year of Investigation BY E. C. HADERLIE Department of Oceanography, Naval Postgraduate School, Monterey, California 93940 (2 Text figures; 2 Tables) INTRODUCTION Since Octoser, 1966, continuous studies have been made on the fouling and boring organisms that attach to or drill into test panels exposed to the marine environment under Municipal Wharf No. 2 in Monterey Harbor. The results of the first year of study have been published (HapERLIE, 1968a). The present paper will summarize progress in the work during the second year, which basi- cally extended from October, 1967, to October, 1968, but continued through December, 1968, on certain exposed panels. In addition to these investigations in the harbor area, studies are also being conducted in the open water of Monterey Bay in water-depths of 50, 100 and 200 feet. Results of two years’ work at the 50 foot level have been published (Haperuiz, 1968b) and data from deeper levels are presently being analyzed. It is planned to continue all these investigations for several more years, for experience has indicated that the results obtained show great variability from year to year and data from many years must be collected before a reasonable idea of the nature of the fouling and boring community can be obtained. When this project was initiated in 1966 the objectives were to obtain information on the kinds of marine organ- isms that settle on or burrow into test panels of a variety of types of material exposed in sea water at different depths under the wharf, to determine the season or sea- sons of settling, to note any correlation between settling of organisms and the temperature or salinity or both of the sea water, to determine any choice of substrate by indi- vidual organisms, to measure rate of growth of the dom- inant calcareous foulers, and to study evidence of seasonal progression or ecological succession over an extended period of time. Data from the first year’s work gave partial answers to some of these problems, but experience also indicated ways in which the experimental procedure should be modified in order to get a more complete picture. These modifications in technique will be explained below. The author wishes to acknowledge the following col- leagues for help in the identifications of organisms: Mr. Jack Gougé (Foraminiferans), Dr. D.J.Reish (Poly- chaetes), Dr. D. P Abbott (Ascidians), Dr. A. H. Cheet- ham (Bryozoans). Mr. Stephen V. Smith made miner- alogical determinations of spirorbid tubes, and Mr. J. R. Lance again assisted in resolving nomenclatural problems with opisthobranchs. Mr. Barry Roth pointed out correct- ly that the bivalves identified as Pecten sp. in my earlier paper were in reality young specimens of Hinnites multi- rugosus (GALE, 1928). Acknowledgment is also due Mr. Jack C. Mellor for help in field work, to my wife, Mrs. A. E. Haderlie, for assistance in the laboratory, and to the Office of Naval Research for financial support. AREA or STUDY As reported in the 1968 paper on fouling and boring organisms in the harbor, the site of the study is near the outer end of Monterey Municipal Wharf No. 2 where the water depth is approximately 21 feet at mean low tide. For a complete description of the site readers are referred to the earlier paper. As before, biweekly surface temperature and salinity measurements were made throughout the year (Figure 1). METHODS Techniques used during the period of study reported on here were similar to those used the previous year, with some modifications. During 1966-1967, collecting panels consisting of standardized 8 inch by 10 inch panels of Wolewli2INo: 2 THE VELIGER Page 183 Temperature Figure 1 Biweekly morning temperatures and salinities at test site for the year October 1, 1967 to October 1, 1968 4 inch marine grade douglas fir plywood were used as the primary collecting surfaces. Panels were placed in stain- less steel racks holding 6 panels vertically and 3 inches apart. To compare at least one other material that has been used in the past as a collecting surface for foulers, panels of 4 inch asbestos board (Johns-Manville Color- lith) were also exposed in racks alongside those containing plywood. It was found that there was essentially no dif ference in the total number of species collected by ply- wood or asbestos board and in settling most foulers did not appear to distinguish between the two substrates. A few organisms settled in slightly greater numbers on plywood, whereas a few others were more abundant on asbestos board, but the differences were not considered significant. To simplify the procedure, during the 1967 to 1968-year reported on here the asbestos board panels were discarded and only plywood panels used. Plywood was selected over asbestos board, for wood panels also collected wood boring organisms of interest in this study. In the 1966-1967 study, one series of panels was sus- pended in the water alongside the wharf where it was exposed to relatively strong sunlight during at least half Page 184 the day. These lighted panels collected a total of 5 species of benthic algae during the year, but otherwise the fouling and boring organisms collected by the lighted panels were very similar to those. collected by panels at the same water depth in the dim-light conditions under the wharf. During this past year, therefore, the lighted series has been discontinued. Again during the 1966-1967 year, one rack of panels designated “floating panels” was rigged so that the rack floated at the sea surface regardless of tidal level. This rack was difficult to keep in place and several panels were lost. During the 1967-1968 year the floating rack was continually lost during storms and was replaced many times. Ultimately this series of panels was abandoned. This lack of data is perhaps not serious, for during 1966 to 1967 the floating panels did not collect a population of foulers and borers much different from panels submerged some distance below the surface. During 1967-1968, then, three series of panels in racks as used the previous year were continued as follows: (1) Intertidal rack. Positioned about 4 feet above the lowest low tide level. The panels in this rack were sub- merged approximately one half the time and exposed to air the other half. Short Term and Cumulative Panels. (2) Shallow rack. Located 1 foot below lowest low tide level. Panels always submerged. Short Term and Cumu- lative Panels. (3) Deep rack. Positioned 14 feet below the lowest low tide level and about 7 feet off the bottom. Short Term and Cumulative Panels. In addition to the above listed three racks a fourth one was added for reasons that will be explained below. This rack was designated as follows: (4) Shallow Long-Term Rack. Positioned 1 foot below the lowest low tide level. Long Term Panels (3 month and 6 month exposure). The basic period covered by the present study was from October 1, 1967, to October 1, 1968. In the case of the panels in the intertidal, shallow and deep racks the routine for placing and retrieving the collecting surfaces was the same as in 1966-1967. Of the 6 panels in each of the racks there were 4 that were left in place for 3 months (Panel C-1), 6 months (Panel C-2), 9 months (Panel C-3), and 12 months (Panel C-4) respectively. These were designated Cumulative Panels. The other 2 panels in each rack were designated Short Term Panels (S-1, S-2, etc.) : one was put in the water on the first of each month and removed for analysis on the first of the following month; the second panel was put in on the 15" of each month and removed one month later. THE VELIGER Vol. 12; No. 2 During the 1966-1967 investigation it was found that the Cumulative Panels exposed for 3, 6, 9, and 12 months showed the most varied and extensive fouling communi- ties. This was to be expected, for many benthic organisms settle only on surfaces that have been colonized by pio- neering fouling organisms. All of the Cumulative Panels were placed in the water at the same time on October 1, 1966. During the course of the first year of this study it was wondered if a panel placed in the water for 3 months (or 6 months) beginning in October would ultimately collect the same fouling community as one placed in the water for 3 months (or 6 months) beginning in January, March, or any other month. To find an answer to this question a new rack was used during 1967-1968. The rack was designated “shallow, long term rack” and was positioned alongside the regular “shallow rack” at 1 foot below low tide. Panels that would remain in the water for 3 months (Panel 3-L) and for 6 months (Panel 6-L) were submerged in this rack. One 3-month panel was placed in the water on October 1, 1967, a second on No- vember 1, 1967, and so on throughout the study period. Six-month panels were submerged every 3 months. The length of exposure of the various panels is shown diagram- matically in Figure 2. As before, the panels were removed from the racks and transported to the laboratory in sea water containers to be examined under a stereoscopic microscope while the panels were submerged in a pan of sea water. After examination, one of the surfaces of each of the Long Term and Cumulative Panels (80 square inches or 5123 cm’) was scraped clean of attached organisms and the scrapings were oven dried at 100° C until the weight was constant. This provided a rough statistical measure of the relative amount of fouling growth accumulated in any one period (see bottom line, Table 2). Short Term Panels usually collected so little in terms of weight that they were not scraped and treated as above. THE FOULING COMMUNITY I. DISCUSSION or ORGANISMS SETTLING on SHORT TERM PANELS Table 1 presents a list of organisms and their relative numbers that settled on panels exposed for 1 month during the period October 1, 1967, to October 15, 1968. A total of 66 different animal species identified at least to genus were recorded. During the previous year, a total of 70 different kinds of organisms was found on similar panels, but this number included 4 species of algae. None of the panels submerged under the wharf during 1967 Woltal 2 No: 2 THE VELIGER Page 185 Interval of Exposure ANNNNUNANNADN Or Ou fw hd we n ° Short Term Panels (3 months) Long Term Panels (6 months) Cumulative aE ee Pf ffs [Fp [mis [7 Jas Jol] > Figure 2 Diagram illustrating period of exposure for test panels from October 1, 1967 to January 1, 1969 to 1968 collected any green, brown, or red algae for, as explained above, none of the racks was placed in water receiving direct sunlight. All panels when first placed in the water collected a surface film of bacteria and benthic diatoms, but none of these was identified. During each of the past 2 years, then, Short Term Panels have collected 66 different kinds of animals. This identical total seems to be merely a coincidence for, al- though the totals were the same, the lists of organisms are not identical for each of the two years. During each year the dominant fouling organisms were the same: en- crusting cheilostomate and cyclostomate bryozoans, cal- careous-tubed serpulid worms and acorn barnacles, The most common boring organism was the gribble Limnoria, and these and other wood borers will be considered later. The following discussion will briefly review the occurrence of the most common organisms of each major group listed in Table 1. Protozoa: Eight different kinds of benthic foraminiferans were observed on the Short ‘Term Panels. Cornuspira lajollensis and Rosalina columbiensis were the only species regularly encountered, but the former was often found in great numbers. The reason that more species of foraminiferans were found during 1967-1968 than in the previous year was due in part to a more determined effort to locate them, but principally because Mr. Jack Gougé examined many of the panels when fresh and picked up forms that had been overlooked previously. The ciliate Folliculina sp. was perhaps the most abundant single protozoan encoun- tered, and it settled on panels at all depths throughout the year. The suctorian Ephelota gemmipara often formed fuzzy forests over the panel surface and attached to hydro- ids such as Obelia. The colonial ciliate Zoothamnium sp. again was found to be common during the summer and fall months. Porifera: Two species of sponges settled on the Short Term Pan- els, but of these only Leucosolenia eleanor was found regularly. Coelenterata: The only coelenterate that settled on the panels with any regularity was the hydroid Obelia sp. which settled during most months of the year. Syncoryne mirabilis, a second hydroid, was encountered only rarely and in small numbers. Page 186 THE VELIGER Vol. 12; No. 2 Platyhelminthes: Four different species of flatworms were recorded on Short Term Panels during 1967-1968. The commonest form encountered was Thysanozoon californicum which occurred only on those panels with a population of the bryozoan Celleporaria brunnea. Nemertea: Nemertean worms were rarely seen on the panels, but two species were observed, each on one occasion, on the intertidal panels only. Ectoprocta (Bryozoa): {Dr. Cheetham of the U.S. National Museum has examined the cheilostomate bryozoans on the panels and has found that the bryozoan identified as Lyrula hippocrepis (Hincks, 1882) in my earlier papers (HapErR.iE, 1968a, 1968b) is in reality Cryptosula pallasiana. In addition, Hippothoa hyalina should be called Celleporella hyalina and Holoporella brunnea should be called Celleporaria brunnea.} During the present study the same 4 encrusting bryo- zoans dominated the Short Term Panels as they did in 1966-1967. Celleporella hyalina, Cryptosula pallasiana, Tubulipora pacifica and Celleporaria brunnea were found on nearly all panels at all depths. During this past year Celleporaria seemed to be much more abundant, and Celleporella less abundant than during the year before. Erect bryozoans were also very common. These were dom- inated by the soft fuzzy Bowerbankia gracilis and by Bugula neritina and B. californica. On a shallow panel submerged from June 15 to July 15, 1968, dozens of tiny Bugula neritina were found, indicating the period of maxi- mum settlement. During most months of the year only one or two specimens of B. neritina were found on any panel. From mid-summer through the fall Crisulipora occidentalis settled on panels in the shallow and deep racks. Annelida: During 1966-1967 spirorbid worms were encountered on the Short Term Panels in abundance second only to encrusting bryozoans. These forms were identified as Spir- orbis spirillum and they settled on the panels at all depths throughout the year. During 1967-1968 spirorbids were again encountered, often in great numbers, and on most Short Term Panels throughout the year. The most intense settling was from mid-April through June when hundreds of small worm tubes were found, particularly on the deep panels. A more careful examination of the tubes of these spirorbids has shown that at least 4 distinct morpho- logical types are present. The largest tubes and most commonly encountered forms are distinctly sculptured, coiled counter-clockwise, and faintly resemble the tubes of Spirorbis nipponicus Oxupa, 1934, as figured in USHakov (1955). Mineralogical analysis of the tubes by Stephen V. Smith has shown these to be composed of aragonite. A second morphological type (and second in abundance on the panels) coils clockwise and has a tube strongly ringed resembling the horn of an antelope such as the sable or oryx. These tubes are composed of calcite with 12% Mg substitution for Ca in the CaCO: lattice. A third form has a very smooth shell and coils clockwise. It is composed of aragonite. The fourth form was only rarely encountered. It is smooth and coils counter-clock- wise and also seems to be composed of aragonite. When removed from the tubes the worms all look remarkably alike. The identity of these spirorbids is therefore in doubt. It is possible that these forms represent 3 or 4 distinct species. Until the systematics is worked out it seems wise to refer to them as Spirorbis spp. A second common serpulid that has been found not only in Monterey Harbor but at depths to 100 feet in open water has been referred to previously only as Serpula sp. (HapEruE, 1968a, 1968b). A more critical examina- tion of these worms during recent months has shown them to be Chitinopoma occidentalis. On deeper panels Chitin- opoma was more abundant than S‘prrorbis. Arthropoda: As in the earlier study in the harbor, the most common- ly encountered arthropod on the fouling panels was the acorn barnacle Balanus crenatus. On the Short Term Panels this barnacle settled in small numbers during most months of the year. There were usually 10 animals or fewer per panel side, and the greatest number seen was 20 per panel side during August, 1968. These results ob- tained during the 1967-1968 year contrast sharply with Explanation to Table 1 (foldout, facing this page —>) * Symbols used at head of columns indicate: S-1, S-2, etc. = Short term panel number as designated in Figure 2 I = Intertidal panels S = Shallow panels D = Deep panels 2 Symbols used in columns indicate: 1 = species present in numbers from 1 to ro individuals or colonies per panel side 2 = species present in numbers from 11 to 20 individuals or colonies per panel side 3 = species present in numbers upward from 20 individuals or colonies per panel side * ui. pari Site Miles nee List of Species, and of Panels where Organisms Settled in Short Term Series Table 1 Protozoa: : Jridia lucida LECALUEY, 1936 Cornuspira lojollaensis Uctito, 1960 Rosalina columbiensis (Cusnman, 1925) Spirillina revertens (Ruumster, 1906) Spirillina vivipara (RHUMBLER, 1906) Patellina corrugata Wriiiamson, 1858 Tubinella funalis (BRADY, 1884) Entosolenia sp. Fildile gemmipara (Hartwic, 1876) Zoothamnium sp. Folliculina sp. Stentor sp. Porifera: Leuconia heathi (Urpan, 1905) Leucosolenia eleanor URBAN, 1905 < a < a ° 4 S|D S-9 D so J sw I} s|D]1| s D S-12 S|D I S-19 1) S|D }*1 o no nm n no rr) a) 7) re , Coelenterata: Obelia sp. Syncoryne mirabilis (AGASSIZ, 1862) Metridium senile (LinNapus, 1767) Platyhelminthes: Stylochoplana gracilis HeatH & McGrecor, 1912 Notoplana acticola (Boone, 1929) Thysanozoon californicum Hyman, 1953 Pseudocerous sp. NO DATA — NO DATA — = Nemertea: Tubulanus sexliniatus (Grirrin, 1898) Tetrastemma nigrifrons Cor, 1904 N. D. Entoprocta: Barentsia gracilis (Lomax, 1886) N. D. Ectoprocta (Bryozoa) : Bowerbankia gracilis O'Donoonue, 1926 Filicrisia franciscana (RobERTSON, 1910) Crista sp. Crisulipora occidentalis Ropertson, 1910 Tubulipora pacifica Robertson, 1910 Bugula neritina (Linnazus, 1758) Bugula californica Ronertson, 1905 Celleporella hyalina (LinnNazus, 1767) Cryplosula pallasiana (Mott, 1803) Scrupocellaria californica Tras, 1857 Scruparia ambigua (v'Orbiony, 1841) Celleporaria brunnea (HincKs, 1884) NO DATA new enn Annelida: Platynereis agassizi (EHLERS, 1868) Pseudopotamilla ocellata Moore, 1905 Spirorbis spp. Chitinopoma occidentalis (Busu, 1904) — NO DATA — =EE Ho Po Ce palin colar, IR Sa ical n 3 Arthropoda; Balanus crenatus Bruouttre, 1789 Balanus glandula Darwin, 1854 Balanus tintinnabulum (Linnagus, 1758) Chthamalus dalli Pruspry, 1916 Lepas anatifera (Linnazus, 1758) Caprella californica Stimpson, 1857 Corophium insidiosum Crawrorp, 1937 Limnoria quadripunctata Hornuts, 1949 NO DATA Loxorhynchus crispatus Stimpson, 1875 Mollusca: Pododesmus cepio (Gray, 1850) Hinnites multirugosus (Gate, 1928) Mytilus edulis Linnazus, 1758 Hiatella arctica (LINNAEUS, 1771) Bankia setacea (Tron, 1863) Coryphella trilineata O'Donoanue, 1921 Hermissenda crassicornis (Escuscnoxtz, 183!) Dendronotus frondosus (Ascantus, 1774) Dendronotus subramosus MacFARLAND, 1966 Doto kya Marcus, 1961 Tiiopha grandis MacFartanp, 1905 Trinchesia albocrusta (MacFartanp, 1966) Polycera atra MacFARLAND, 1905 NO DATA : Aegires albopunctatus MacFarLanp, 1905 Kehinodenmata: Strongylocentrotus sp. —CPhiothrix Spiculata LeConte, 1851 NO DATA\ [os Vol. 12; No. 2 THE VELIGER Page 187 the former year where during certain months such as March, June and August there were massive setlements of up to 25 barnacles per square inch of panel surface. During the present study there was no one period when B. crenatus settled in great numbers. On panels in deeper water in the open bay, where massive settlement of B. crenatus occurred in March and August, 1967, no such peak in settling was recorded in the same months of 1968 (Haper.iz, 1968b). Thus the data from the harbor and from open water are in agreement; no major seasonal settlement of B. crenatus occurred in 1968. The reason for this is not obvious. The water temperature and salin- ity recorded in 1968 was not much different from the previous year (Figure 1). This shows again that one must make observations over a number of years before one can generalize regarding season of settling of fouling organisms. The small acorn barnacle Chthamalus dalli was re- corded fairly regularly from panels exposed in the inter- tidal rack. The peak period of settlement was between February 15 and March 15, 1968, when over 100 barnacles settled on each side of a wooden intertidal panel. It was interesting to note that the barnacles settled only on the dark areas of the wood and on pencilled letters used for marking the panels. Perhaps a very dark board or a panel of asbestos board would have collected many more of these. Other barnacles recorded from Short Term Panels were a few specimens of Balanus glandulus, one of B. tintin- nabulum and one of Lepas anatifera. Mollusca: The nestling clam Hiatella arctica was commonly found on Short Term Panels as a tiny, freely-moving organism. In the spring months there were often dozens of these on every panel. Pododesmus cepio was also found fairly regu- larly throughout the year, but only in small numbers. Mytilus edulis, a dominant animal on the pilings of the Wharf, settled only occasionally on Short Term Panels. Many nudibranchs were found but of these only Hermis- senda crassicornis was of regular occurrence. Echinodermata: Small green sea urchins were recorded on most panels during the spring and summer months. These were invari- ably so small as to make specific identification impossible. Chordata (Tunicata): As was true in the previous year, during 1967-1968 no tunicates settled on the Short Term Panels, yet, as will be seen, did settle on the Long Term and Cumulative Panels. This again confirms what ScHEER (1945) and others have found, namely, that tunicates settle only on surfaces that have been colonized by earlier foulers such as bryozoans. II, DEPTH PREFERENCE As can be seen from Table 1, most of the organisms encountered in this survey showed little preference for panels at different depths, and any one organism could be found on panels at all depths at one time or another. Exceptions to this generalization, however, were found among certain of the encrusting bryozoa. Tubulipora pa- cifica, for example, was exceedingly common on the con- tinually submerged panels, but was found on only one occasion on an intertidal panel. Celleporaria brunnea was also common on submerged panels, especially the shallow panels, but rare on the intertidal ones. Crisulipora occi- dentalis definitely preferred the deep panels. On the other hand, the barnacles Balanus glandula and Chthamalus dalli were found only on intertidal panels. III. DISCUSSION or ORGANISMS SETTLING on LONG TERM anno CUMULATIVE PANELS Table 2 presents data collected from Long Term and Cu- mulative Panels during 1967-1968. As indicated in Figure 2 and discussed earlier in this paper, the panels desig- nated Long Term Panels were those that were immersed in racks suspended one foot below low tide level. Most of these panels were exposed for 3 month periods, one being submerged on the first of every month throughout the year and removed for analysis 3 months later. A second group of 4 Long Term Panels in the same rack remained in the water for 6 months; one panel was immersed on October 1, a second on January 1, a third on April 1 and the fourth on July 1. Cumulative Panels, on the other hand, were submerged at the 3 depths discussed earlier in connection with Short Term Panels, namely in intertidal, shallow and deep racks. All the Cumulative Panels were submerged at the same time on October 1, 1967. From each of 3 racks one panel was removed at the end of 3 months, 6 months, 9 months and finally at the end of 12 months. The data from these panels are given in Table 2, right side. The rea- son there is no column for data from shallow panels at 3 and 6 months is that these data were incorporated into the Page 188 THE VELIGER Vol. 12; No. 2 appropriate 3 or 6 month columns under Long Term Panels. On these Long Term and Cumulative Panels a total of 88 different animals identified at least to genus were recorded. This was about the same total number as found in 1966-1967, but the list does include several animals not recorded earlier, particularly foraminiferans. And because none of the panels was exposed to bright light, no benthic algae were found on the 1967-1968 series. In the discussion that follows, the dominant animals of each major group that settled in any numbers on the Long Term and Cumulative Panels will be discussed briefly. Protozoa: A total of 15 different kinds of benthic foraminiferans were recorded during the year, Many of these were found on only one or two occasions, but Cornuspira lajollensis was found regularly throughout the year and often was present in great numbers. The ciliate Folliculina sp. was also exceedingly common throughout most of the year. On Cumulative Panels in the deep rack removed after 3, 6, 9, and 12 months, this large ciliate was often one of the dominant foulers in terms of numbers of animals present. On the deep panel removed on January 1, 1968, after 3 months exposure, Folliculina was present in thousands and blackened the surface of the panel. The same was true of a shallow panel removed April 1, 1968. Porifera: The sponge Leucosolenia eleanor was encountered on nearly all of the panels except the Cumulative Panels exposed in the intertidal. The anastomosing tubes often formed large clusters 5 cm or more in diameter on panels in the water for 3 months or more. Large globular speci- mens of Leuconia heathi up to 3cm in diameter were present in fair numbers on deep panels in the water for 6 months, and on the 9-month panel it was second only to the bryozoan Crisulipora occidentalis as the dominant organism. Coelenterata: No coelenterates were common on the panels. Obelia sp. was found sporadically, but only on an intertidal panel in the water 6 months was it ever abundant. Metridium senile was recorded only twice: on an intertidal and a deep panel exposed 3 months beginning October 1, 1967. On each panel there was a single anemone | cm in dia- meter. It is surprising that more individuals of Metridium did not settle on the panels, for this anemone along with Corynactis californica CaRLGREN, 1936, is among the dominant fouling organisms on the wharf pilings near the position where the collecting panels were exposed. It is possible that a new surface must be in the water for a period much greater than 12 months before it is suitable for settlement of these anemones. In the 1966-1967 survey, Corynactis was encountered a few times on panels in the water 9 months or more, but this past year none were recorded. Platyhelminthes: Six species of flatworms were found on the Long Term and Cumulative Panels but of these only 'Thysanozoon californicum was common. This very unusual flatworm is papillated on the dorsal surface and in color and texture closely matches the encrusting bryozoan Celleporaria brunnea on which it lives. The worm is elliptical in out- line and the largest individuals seen were 10 mm long. Thysanozoon was encountered regularly, especially on the 3 and 6 month Long Term Panels, and throughout the year except for late spring and early summer. Never was Thysanozoon found on a panel unless Celleporaria was established there, and in all cases the flatworm was found pressed tightly against the bryozoan colony. It was found to be very sluggish and moved only when prodded. When the flatworm was loosened and turned over it was often seen to have the pharynx extended and pressed over the zooids and in many cases the zooecium had turned white in color and the living zooids were gone. This indicates strongly that Thysanozoon feeds directly on the zooids of Celleporaria. Ectoprocta (Bryozoa) : As can be seen in Table 2, the bryozoans were clearly the dominant fouling animals on the Long Term and Cu- mulative panels during the 1967-1968 year as they had Explanation to Table 2 (foldout, facing this page —>) * Symbols used at head of columns indicate: 3L1, 3L2, ... 6L1, 6L2, etc. = Panel numbers as designated in Figure 2 I = Intertidal panels GC S = Shallow panels D = Deep panels 2 Symbols used in columns indicate: . I = species present in numbers from 1 to 10 individuals or colonies per panel side 2 = species present in numbers from 11 to 20 individuals or colonies per panel side 3 = species present in numbers upward from 20 individuals or colonies per panel side VEC INOS ‘ i sdieal Seti, AH nl bin, Manica wnt a Per een vs i k A bose ie ea ncn tenn sete ide ays pte by ear yest) AS | pix 1 aoa (6), ack Fi 4 ’ a ial <} = 5 aah =. ’ i 3 tele - * —_" Pers soon es —— ome oF Table 2 List of Species, and of Panels where Organisms Settled in Long Term and Cumulative Series, October 1, 1967 to January 1, 1969 Species Protozoa: Inidia lucida LeCarury, 1936 Cornuspira lajollaensts Ucuto, 1960 Rosalina columbiensis (Cusuman, 1925) Spirillina revertens (RHuUMBLER, 1906) Spirillina vivipara (RHUMBLER, 1906) Tubinella funalis (Bravy, 1884) Saccamina sp. Cibicides sp. Rotorbinella campanulata (GALLOWAY & WISSLER, 1927) Haplophragmoides columbiense CusuMan, 1925 Quinqueloculina sp. Spiroloculina hyalina Scuuze, 1875 Miliolinella sp. Bolvina sp. Gordiospira sp. Folliculina sp. Zoothamnium sp. Ephelota gemmipara (Hartwic, 1876) Long Term Panels Porifera: Leuconia heathi (Urpan, 1905) Leucosolenia eleanor Urnan, 1905 Halichondria panicea (Pautas, 1766) Rhabdodermella nuttingi Ursan, 1902 Coelenterata: Obelia sp. Syncoryne mirabilis (Acassiz, 1862) Metridium senile (Linnazus, 1767) Platyhelminthes: Kaburakia excelsa Bock, 1925 Stylochoplana gracilis Heatu & McGrecor, 1912 Notoplana acticola (Boone, 1929) Thysanozoon californicum Hyman, 1953 Stylochus sp. Pseudocerous sp. Nemertea: Tubulanus sexliniatus (GrirFin, 1898) Micrura verrilli Cor, 1901 Amphiporus bimaculatus Cor, 1901 Amphiporus imparispinosus Grirrin, 1898 Entoprocta; Barentsia gracilis (Lomax, 1886) Ectoprocta (Bryozoa) : Bowerbankia gracilis O’Donocuur, 1926 Filicrisia franciscana (Ropertrson, 1910) Crisia sp. Crisulipora occidentalis Rosrrtson, 1910 Tubulipora pacifica Roverrson, 1910 Bugula neritina (Linnagus, 1758) Bugula californica Ronertson, 1905 Celleporella hyalina (Linnaeus, 1767) Cryptosula pallasiana (Mout, 1803) Scrupocellaria californica Trask, 1857 Scruparia ambigua (p’Oruicny, 1841) Celleporaria brunnea (Hincxs, 1884) Dendrobeania lichenoides (Ronertson, 1900) Annelida: Platynereis agassizt (Euvers, 1868) Nereis vexillosa Grune, 1851 Halosydna brevisetosa Kinnerc, 1855 Sabellaria cementarium Moore, 1906 Sabella sp. Pseudopotamilla ocellata Moore, 1905 Spirorbis spp. Chitinopoma occidentalis (Busu, 1904) Polydora brachycephala Harrman, 1936 Sipunculoidea: Phascolosoma agassizit KEFERSTEIN, 1866 Arthropoda: Balanus nubilis Darwin, 1854 Balanus crenatus Brucuitre, 1789 Balanus glandula Darwin, 1854 Balanus tintinnabulum (LINNaA®’ Chthamalus dalli Prrsnry, 1916 Caprella californica Stimeson, 1857 Corophium insidiosum Grawrorp, 1937 Limnoria quadripunctata Houruurs, 1949 Loxorhynchus_crispatus Sviaeson, 1875 Mollusca: Pododesmus cepio (Gray, 1850) Hinnites multirugosus (Gaus, 1928) Mytilus edulis Linnasus, 1758 Hiatella arctica (Linnagus, 1771) Bankia setacea (TRyon, 1863) Hermissenda crassicornis (EscuscHoxrz, 1831) Acanthodoris brunnea MacFarvanp, 1905 Doto kya Marcus, 1961 Triopha carpenteri (Srearns, 1873) Triopha grandis MacFartanp, 1905 Trinchesia albocrusta (MaGFartanp, 1966) Polycera atra MacFartann, 1905 Aegires albopunctatus MacFartanp, 1905 Echinodermata: Strongylocentrotus purpuratus (Stinson, 1857) Strongylocentrotus franciscanus (Agassiz, 1872) Strongylocentrotus spp. Ophiothrix spiculata LyConts, 1851 Rupentacta quinguesemita (Seuenxa, 1867) Chordata (Tanicata) : Aplidium solidum (Rrrrex & Forsytx, 1917) Ascidia ceretodes (HUNTSMAN, 1912) Styela truncata Rerrsr, 1901 Dry weight (gr) of fouling growth s, 1758) 9.2 9.0) 8.1 7.3) 10.0)16.1] 13.0}22.41 10 3L 12 3L 6L Cumulative Panels 6 months 6 mos. 1| 2) 3 6L |6L S 3 mos. 9 mos. eee 1513 19.2/13.5 6.8 me | | 25.1/61.3/29.7} 1.0} 5.0] 2.3/14.7|30.6/77.6}45.94 0.0/109 32.3 meee Vol. 12; No. 2 THE VELIGER Page 189 been the previous year. Twelve species were found regu- larly, and often in great numbers, and many of these settled on panels immersed at different periods during the year indicating that there are settling larvae present througout the year. In many cases it was difficult to decide which of these bryozoans were truly dominant, for in many cases a panel was completely covered with encrust- ing colonies of Tubulipora pacifica, Cryptosula pallasiana and Celleporaria brunnea. In other cases the panel might be practically covered with a thick growth of Crisulipora occidentalis sprinkled with fewer colonies of Bugula neri- tina and B. californica. On the Cumulative Panels in the water 3, 6, 9, and 12 months from October 1, 1967, it was obvious that most of the bryozoans preferred the panels in the shallow and deep racks where they were constantly submerged. Only Bowerbankia gracilis and Cryptosula pallasiana occurred commonly and abundantly on intertidal panels, and on the 9 and 12 month intertidal panels Bowerbankia was the dominant animal and formed a fuzzy mass over every- thing. Some of the other forms also showed a depth pref- erence. Crisulipora occidentalis, for example, was found commonly on panels at both the shallow and deep posi- tions, but only on the deep ones did it become the domi- nant form. On panels in the shallow position Celleporaria was most abundant with Cryptosula and Tubulipora next. As regards the Long Term Panels that were exposed in racks at the shallow depth for 3 or 6 months but at varying times throughout the year, the dominant animal in all cases was Celleporaria brunnea. Every panel of this series collected massive numbers of Celleporaria colonies. At the end of any 3 month period, the wooden panel would be practically totally encrusted with these colonies, each averaging 10 to 20 mm in diameter, with Cryptosula and Tubulipora filling any blank space. Often the Celle- poraria colonies had completely overgrown and smothered other encrusting bryozoans such as Celleporella hyalina, acorn barnacles and serpulid worm tubes. It is interesting to note also that Celleporaria settled fairly evenly and had similar growth rates throughout the year, although most of the colonies were slightly smaller in size in the winter months compared to the summer. In other words, a panel removed in January, in May, in August or in Octo- ber after being in the water 3 months had a very similar population of Celleporaria. This, however, held for panels in the shallow position only. No equivalent series was exposed in deeper water under the wharf, but circum- stantial evidence from other deep panels would indicate that perhaps Crisulipora occidentalis would be the dom- inant form throughout the year at this position. Annelida: Calcareous serpulid worms were commonly found on most Long Term and Cumulative Panels. The most abun- dant of these were spirorbids which will be simply referred to as Spirorbis spp. A description of the 4 morphological types of these spirorbids, based on the tube form and shape, was given earlier under the section dealing with annelids on Short Term Panels. On the Long Term Panels the largest and most abundant of these were those with sculptured tubes spiralling counter-clockwise. Many of these were 2.5 mm in maximum dimension. The smallest were the smooth forms spiralling counter-clockwise, the largest of which were 0.9 mm across. The second common serpulid was Chitinopoma occi- dentalis (referred to incorrectly in 2 earlier papers as Serpula sp. (HaperuE, 1968a, 1968b) ). This serpulid is distinct in having a tube with a prominent keel running its full length and ending in a denticle over the orifice. The tubes were often twisted and distorted, particularly on older panels and measured up to 50 mm in length. Arthropoda: During the 1966-1967 survey and in earlier pilot studies in the harbor (MomMsEN, 1966; Miter, 1966), the acorn barnacle Balanus crenatus was one of the com- mon foulers on Cumulative Panels and was often the dominant animal. As pointed out in the discussion of B. crenatus on Short Term Panels, the 1967-1968 season showed very few settling barnacles anywhere in the har- bor or out in open water of the bay. It is not surprising, then, that Long Term and Cumulative Panels collected few barnacles. At no time were more than 20 B. crenatus found on any one panel, regardless of the length of exposure. Balanus glandula and Chthamalus dalli occurred in small numbers on a few of the intertidal Long Term Panels, and Balanus tintinnabulum on a few intertidal and shallow panels. The giant acorn barnacle, Balanus nubilis, made a single solitary appearance on an inter- tidal panel exposed for 9 months. This barnacle which is exceedingly common on the piles in Monterey Harbor has not been recorded from a test panel before during these studies. Mollusca: A variety of mollusks was encountered on the Long Term and Cumulative Panels, most of them opistho- branchs, and usually in small numbers. Hermuissenda crassicornis was the most common of these. The nestling Page 190 clam Hiatella arctica was fairly common on panels that had an extensive growth of erect bryozoans or sponges that created crevices in which this animal could live. On a shallow panel exposed 3 months and removed April 1, 1968, there were hundreds of small Hiatella nestled in the bryozoans. Mytilus edulis is a very common fouler on the wharf pilings of the harbor, yet it settled only in small numbers and then only on panels in the water 6 months or more and in the intertidal position. The maximum size was 4 cm and this was achieved on a panel exposed 12 months. Yet on the intertidal rack itself a large cluster of about 30 individuals of M. edulis was found attached to the board that formed the bottom of the rack. Some of these were large (7 cm and more). As mentioned above, no mussel was found on any panels exposed for less than 6 months, so it is possible these large animals had developed in half a year or less. Echinodermata: Small sea urchins (Strongylocentrotus spp.) 2.0mm and less in diameter were found on most of the Long Term Panels and occasionally in fairly great numbers. These were impossible to identify to species. On some of the Cumulative Panels in the water 9 months or more, however, a few urchins of larger size were found and could be assigned to one or the other of the two common species of Strongylocentrotus. Small ophiuroids (Ophi- othrix sp.) were also encountered on several of the Long Term and Cumulative Panels. Chordata (Tunicata): Three species of tunicates were found on some of the Long Term and Cumulative Panels, but invariably in small numbers. Ascidia ceretodes and Styela truncata ap- peared on panels, other than those in the intertidal rack, that had been in the water 3 months or longer. The latter were always small (5 mm or less) but specimens of Asci- dia ceretodes on the 12 month panels were 50mm in diameter. Aplidium solidum appeared on only a few panels in the water 6 months or more. On an intertidal panel in the water 12 months, specimens of Aplidium solidum attained a diameter of 50 mm. IV, ECOLOGICAL SUCCESSION on LONG TERM PANELS As noted earlier in the paper, during the year’s work reported on here a rack of panels called Long Term Panels was submerged one foot below low tide level. Some THE VELIGER Vol. 12; No. 2 of these panels (3-L-1, 3-L-2, etc.; see Figure 1) were immersed on the first of each month and removed 3 months later. Another group of 4 panels exposed at 3 month intervals remained in the water for 6 months. Using these panels it was hoped to determine something regarding ecological succession. Specifically, these panels were exposed to determine if the same or different popu- lations of animals would collect during different 3 and 6 month periods of submersion during the year. The 3 month panels developed at the end of their period of submergence essentially the same populations of animals regardless of the month when initially sub- merged. Encrusting bryozoans dominated by Celleporaria brunnea, but including Tubulipora pacifica and Crypto- sula pallasiana practically covered each 3 month panel, and a panel removed in January looked very much like one removed in April or September. The colonies of these bryozoans were smaller in size in the winter months, how- ever, and this can be seen from the data for total biomass (bottom line, ‘Table 2). Minimum biomass accumulated during the November 1 to February 1 period (5.0 g per panel side) and the maximum accumulated during the May | to August | period (22.4 g per panel side). This difference was due mainly to larger and thicker bryozoan colonies in summer rather than more individual colonies. ScHEER (1945) found that in the harbor at Newport, California, a definite ecological succession occurred on submerged panels involving a bacteria-diatom-bryozoan- mussel sequence. In his studies a panel exposed in Decem- ber went through the same sequence as one exposed in March or April. He found that the time relations varied, but the sequence did not. The panels exposed in this study in Monterey Harbor were apparently not submerged long enough to develop a final climax community, but the evidence indicates that a true ecological succession such as SCHEER observed is involved. The 4 6-month panels exposed at different 6-month periods during the year collected essentially the same kinds of animals as the 3 month panels. Again, the en- crusting bryozoans, especially Celleporaria brunnea, dom- inated the community, but on a panel exposed from April 1 to October 1 and another exposed from July 1 to January 1, the erect bryozoan Crisulipora occidentalis formed clusters up to 4m high and contributed signifi- cantly to the total biomass. The evidence indicates that the community developed. by the end of 3 months does not change significantly during an additional 3 months exposure. As can be seen from the data at the bottom of Table 2, the total accumulated biomass on the 6 month panels showed some strange variations. During the periods Oc- tober 1 to April 1 and April 1 to October 1, the panels Vole 12; No. 2 THE VELIGER Page 191 collected a total dried biomass of 56.8 g and 61.3 g re- spectively. Yet in the 6 month periods January 1 to July 1 and July 1 to January 1, the panels collected roughly only half this biomass, namely 25.1 g and 29.7 g. WOOD BORING ORGANISMS During 1967-1968 the same two species of wood borers were encountered as in the previous year. On the Short Term Panels, Limnoria quadripunctata was found through- out the year, but there were usually fewer than 10 gribbles on any one panel and many of these were moving freely over the panel surface or were just beginning to excavate a burrow. On an intertidal panel removed after one month on May 15, 1968, an adult and several young but free gribbles were seen in a shallow burrow. The tiny young had not yet begun to burrow. This is the first instance in these studies where recently released young Limnoria have been seen. At one time or another gribbles were found on panels exposed at all depths, but they preferred the intertidal panels or those submerged in the shallow position. On the Long Term and Cumulative Panels L. quadripunctata was found on every panel. On those exposed for 3 months, up to 25 mature animals could usually be found in burrows under the bryozoan colonies, yet only the intertidal and shallow panels ex- posed for 12 months showed extensive damage to the wood. On some of these, however, the outer lamella of the plywood was often riddled with Limnoria burrows. The second wood borer, Bankia setacea, was found on many of the Short Term Panels as tiny calcareous bodies 0.2 to 0.3mm in diameter with 2 siphonal apertures separated by a calcareous bridge, but no siphons or pallets were developed. These had barely penetrated the wood surface. QuayLE (1959) has found that Bankia attains this size and morphology within 4 days after initial penetration of the wood. Never were more than 5 Bankia seen on any one panel, and the borer settled mainly on shallow and deep panels, but on one occasion on an intertidal panel. As can be seen from Table 1, Bankia settled on Short Term panels in October, Decem- ber, January, February, April and July. There was no one period of maximum settling in 1967-1968. The range of months over which settling occurred was broader than has been found to be true in the open water of the bay (Haperuiz, 1968b) where settling occurred from Decem- ber through June. In the Long Term and Cumulative Panels, Bankia was also found, but rarely, and usually only 1 or 2 small specimens per panel. Even panels exposed for 12 months harbored few Bankia, yet the 1-inch redwood boards of the shallow and deep racks were riddled with. burrows of these shipworms at the end of 12 months, exposure. This indicates that } inch douglas fir plywood is a poor collector for Bankia. A project now in progress in Monte- rey Harbor using 1 inch and 4 inch thick boards shows a far greater abundance of Bankia than would be suspected from past studies using plywood panels as collecting’ sur- faces. Results of these studies on borers will be reported in due time. SUMMARY (1) In continuation of a study initiated in Monterey Harbor in 1966, a series of plywood panels were exposed to the marine environment under Monterey Municipal Wharf No. 2 at positions in the intertidal, one foot below and 14 feet below low tide level. The period of study in this report was from October 1, 1967, to Octo- ber 1, 1968, with certain panels being observed through December, 1968. (2) Certain panels (termed Short Term Panels) were exposed at each of the 3 positions for one month periods throughout the year. These panels made it possible to determine season of settlement of at least the pioneering fouling and boring communities. Other panels (termed Long Term and Cumulative panels) remained exposed for from 3 to 12 months. These were immersed at various times throughout the year and made it possible to measure the rate of growth of many organisms, to observe ecological succession and to de- termine the nature of the dominant fouling community. (3) A total of 66 species of animals settled on the Short Term Panels during the year, while on the Long Term and Cumulative Panels a total of 88 different species were encountered. (4) Encrusting and erect bryozoans were the dominant fouling animals on all the panels. These included Celle- poraria brunnea, Tubulipora pacifica, Cryptosula pal- lasiana, and Crisulipora occidentalis. (5) In contrast to the 1966-1967 year of study, few acorn barnacles were recorded during this past year and no period of mass settling was observed. (6) As before, serpulid worms (Spirorbis spp. and Chi- tinopoma occidentalis) were the most common annelids. (7) Long Term Panels exposed for 3 and 6 months at dif ferent periods throughout the year collected essentially Page 192 THE VELIGER Vol. 12; No. 2 the same population of animals regardless of the month of initial exposure. The dominant forms were encrusting bryozoans. (8) The gribble Limnoria quadripunctata was commonly seen on and burrowing into the plywood panels through- out the year, but in small numbers. The shipworm Bankia setacea was also recorded in small numbers in many of the submerged panels, but there is evidence that }-inch plywood is not a suitable collector of ship- worms and does not give a true indication of the number present. LITERATURE CITED Haper.iz, Eucene Ciinton 1968a. Marine fouling and boring organisms in Monterey Har- bor. The Veliger 10 (4): 327-341; plt. 49; 3 text figs. (1 April 1968) 1968b. Marine boring and fouling organisms in open water of Monterey Bay, California. pp. 658-679 In: Biodeteriora- tion of materials; microbiological and allied aspects. A. H. Watters & J.S.Etprick, Eds. Elsevier Publ. Co., Barking, England MILLER, THomas LERoy 1966. Marine fouling organisms in Monterey Harbor, Cali- fornia. Unpubl. Master's Thes. U.S. Naval Postgrad. School, Monterey, Calif. (October 1966) MomMsEN, DurwarD BELMONT 1966. A study of marine fouling in Monterey Harbor. Unpub. Master’s Thes. U.S. Naval Postgrad. School, Monte- rey, Calif. (May 1966) Quay _e, Danie BraNcH 1959. The early development of Bankia setacea Tryon. pp. 157-174 In: Marine boring and fouling organisms. Washington Univ. Press, Seattle ScHEER, BrapDLey Titus 1945. The development of marine fouling communities. Biol. Bull. 89 (1): 103 - 121 Usnakoy, P V. 1955. Polychaeta of the far eastern seas of the U.S.S.R. Zool. Inst. Acad. Sci. U.S. S.R., Moscow Vol. 12; No. 2 THE VELIGER Page 193 Population Characteristics of Protothaca staminea (ConrAD) from Mugu Lagoon, California RONALD R. SCHMIDT Department of Geology, University of California, Los Angeles, California 90024 AND JOHN E. WARME Department of Geology, Rice University, Houston, Texas 77001 (9 Text figures) INTRODUCTION STUDIES OF AGE STRUCTURES provide estimates of popula- tion characteristics such as growth rate, average and maximum longevity, and mortality rate. Protothaca sta- minea (Conrab, 1837), the little-neck clam, is one of the species of mollusks particularly useful for population studies because it exhibits accentuated growth lines on the surface of the shell. These can be interpreted as annual rings, giving an age in years and a record of growth rate for each shell. The purpose of this study is to compare age and size characteristics for a live population of Protothaca stami- nea from Mugu Lagoon with the same properties for the accumulating dead shells. Analysis of the dead shells pro- vides information on mortality rate and the effect of predatory gastropods on this species. How population dynamics are reflected in the size- frequency distributions of modern and fossil shell deposits is a primary concern of paleoecology. Of the several factors that contribute to the final size composition of an in situ accumulation of shells, growth rate and mortality rate are the most important. For our population of Proto- thaca staminea in Mugu Lagoon, the size-frequency dis- tribution of the dead shells is bimodal: a high peak of juveniles and a smaller peak of adults. This is the conse- quence of a high-to-low growth rate and, particularly, a sigmoidal-shaped mortality rate not generally considered in models of population dynamics. SAMPLES rrom MUGU LAGOON Location: The eastern arm of Mugu Lagoon (Figure 1), just west of Point Mugu (34°30’N Latitude; 119°24’ W Longitude), represents one of the few lagoonal environ- ments along the southern California coast that has not been seriously polluted nor altered by the activities of man. The eastern arm is shallow, being nowhere more than 3m deep at low tide. Hydrography is tidally con- trolled and salinity essentially normal marine (approxi- mately 34%). The general physical and biological aspects of Mugu Lagoon have been treated elsewhere (WARME, 1966). Dense populations of clams are present in most subtidal and lower intertidal habitats in the lagoon. Our samples were collected from a small channel between an island and a mud flat (Figure 1). In order to get a representa- tive sample of the shelled fauna, two parallel transects were established normal to the length of the channel. Five sample stations were picked along each transect at intervals of about 10 m, and marked by semi-permanent stakes. Profiles of the transects and the positions and elevations of the samples are shown in Figure 2. Sampling was completed on the afternoon of May 22, 1964, during a period of low tide inside the lagoon. Sampling Procedure: A hollow cylinder with a cross-sectional area of {m’ and a height of 75 cm, was used to facilitate sampling (Fig- Page 194 THE VELIGER Vol. 12; No. 2 Cc Sampling Area Stations 1 to 10 100 meters 4, |Marsh > Me i ie jee Se SS) L_» | il te Sh N Barren W en = a Ve? Zone oe ay: S [|Eel Grass aia My Mugu ) 4 (( The Eastern Region ae Va v1 | ) = Lagoon WIL | | CoS \ rs ( . Wh Ae a we ip Pee S/, Pacific Ocean of Mugu Lagoon 600 meters SSS SSS) 80 km Santa ‘ : _ Barbara (Ventura , *~1 County = TN VENTURA \ t =" Los N Mugu \_ -— Angeles Lagoon ° 3 Figure 1 LOCATION MAP Mugu Lagoon is situated on the coast of southern California between Los Angeles and Santa Barbara (A). The sampling area of Stations 1-10 is located in a channel between a small island and a tidal flat in the eastern arm of Mugu Lagoon (B and C) ure 3). This sampler can be pushed into loose sand and mud by means of two handles, thus isolating equal areas and known volumes of sediment at each sample location. The sediment within the cylinder can be removed without slumping of material from the sides. Each sample was removed from the cylinder by shovel and washed at the sample site to separate sand and mud from living and dead shells. Washing was accomplished with the aid of a screen with square openings, 3 mm on a side, set in a wooden frame. The living and dead shells thus collected were sorted, identified, and counted. Three clam species dominated both the live and dead assemblages in our samples: Protothaca staminea (Con- RAD), Macoma nasuta (Conran, 1837), and Tagelus californianus (Conrap, 1837). All were abundant enough to be used for population studies (Figure 2), but only the shell of PR staminea has readily discernible growth rings Number of live animals Feet above mean sea level that can be used in estimating ages and growth rates. Protothaca also has the advantage of a robust shell which is not very susceptible to breakage during sampling. SIZE anp AGE MEASUREMENTS Sizes, defined as the greatest anterior to posterior length, were measured with calipers to the nearest 0.1 mm. Because many pelecypods add smaller increments of shell during the winter months, their shells commonly show a eo) Number of live animals fo) SB ®Ss ° o} Z = Om mM 5 é Channel profile Feet above mean sea level I 2 3 4 5 =. *'5 O° Meters =a Cross-section of Traverse I ma Protothaca staminea aA Macoma nasuta CJ Tagelus californianus ] hannel profile n g oD S| ° | Histograms represent the three most abundant pelecypods of Stations 1-10 in relation to Transects I and II. Elevations were obtained by transit survey from a known benchmark. Low water in the channel is just above mean sea level Cross-section of Traverse II Figure 2 crowding of growth lines or a “winter check.” These are clearly visible on Protothaca staminea. “Annual rings” were measured on each shell collected, and the measur- ments indicating annual increments were recorded for each year of growth. Most of the clams were less than 2 years old; thus data for the older and larger classes are based on fewer measurements. The “annual ring” method of age determination has been discussed by WeyMouTH (1923) for Tivela stultorum (Mawe, 1823); by Orron (1926) for Cardium edule LinNAEuS, 1758; and by FRASER & SmitH (1928a) for Paphia [= Protothaca] staminea (Conrap, 1837) and (1928b) for Saxidomus giganteus (DESHAYES, 1839). Vol. 12; No. 2 “Disturbance checks” may also be present; these can sometimes be recognized and discounted, especially after looking at many specimens from a given area. For some species a plot of the class-frequency of all rings may help to distinguish between disturbance and winter checks (e. g., Craic & Hatiam, 1963, p. 738). Figure 3 Sampling equipment used. The specially constructed cylinder, with a 4m? cross-sectional area, was pushed 75cm into the soft sub- stratum. Equal volumes (3/16 m3) of muddy sand were sieved at each station POPULATION CHARACTERISTICS oF LIVE Protothaca In the 10 samples collected in Mugu Lagoon, there were 180 live Protothaca staminea. Densities in individual samples ranged from 1 to 31. The maximum values were found in the deepest sample in each transect. These 2 samples(Figure 2, nos. 5 and 7) also included a greater proportion of larger individuals. Age and Size: The distribution of ages within the total living popula- tion is shown in Figure 4. There is a maximum number of individuals which are up to one year old, and progressively fewer individuals in the older year classes. The 7 year time span represented in Figure 4 shows no clear “good” or “bad” years in which reproduction or spatfall may have been significantly greater or less than in other years. The results of size-frequency measurements are pre- sented in Figure 5. Truncation of the smallest classes reflects the screen size openings used in collecting the samples. The histogram is polymodal, the first peak re- flecting the one-year or less class; the second peak is THE VELIGER Page 195 60 he aa 40 #30 I ° o Ee) 3 3 Z erem sas 5. 6 078 Age in years Figure 4 Age-frequency distribution of live Protothaca staminea, Stations 1- 10, Mugu Lagoon mostly the one and some two year olds; the third peak is largely composed of two year olds with some three and four year olds. The last peak represents individuals in their fourth to seventh years. The position of the peaks would be different if the samples had been collected at other times during the year, being offset to the right as growth proceeds. This would be evident particularly in the faster growing younger classes. However, the overall geometry of the curve should remain skewed as shown in Figure 5. Number of specimens 40 50 o 3 Length in mm Figure 5 Size-frequency distribution of live Protothaca staminea, Stations 1 - 10, Mugu Lagoon Average Growth Rate: The pattern of growth for Protothaca staminea is similar to that known for other bivalves, with rapid early growth and a steady decline in rate with age (HaLtam, 1967, p. 32). Figure 6 illustrates the average growth rate of P staminea collected from the eastern arm of Mugu Lagoon. With the exception of the first year, the growth rate of P. staminea for this particular locality in Mugu Lagoon is Page 196 Length in mm Bite § © 7 8B OD Age in years Figure 6 Average growth rate of living Protothaca staminea, Stations 1- 10, Mugu Lagoon considerably lower than that measured by FRASER & SmitH (1928a) for localities around Vancouver Island, British Columbia. Migration and Food: On analysis of age, size, and rate of growth for our samples, size differences appear to be related to age and not to rate of growth. The average rate of growth is the same throughout the channel. There is a proportionately greater number of older (and larger) clams in the deeper part of the channel. This may be accounted for by the fact that Protothaca staminea can move laterally at the surface of the substrate by a see-saw or rocking motion, leaving a U- or V-shaped depression on the surface. These trails can be several decimeters long, and once recognized in the field a little-neck clam will invariably be found at one end or the other. The adult Protothaca may be moving in response to a more favorable food source. The center of the channel has the greatest water exchange and is always covered with water. It may therefore rep- resent the location of maximum food supply and place of maximum feeding time for the clams compared to the higher, intertidal parts of the channel. Fraser & SmitH (1928a) made extensive population studies of live Protothaca staminea from the beaches of Vancouver Island, British Columbia. They found that Pro- tothaca populations which are protected from currents and waves tended to exhibit a relatively high standing crop of juvenile and young adult individuals. In more exposed localities the populations contained relatively fewer young individuals whose growth was slow in their earlier years, but which grew better than average in their THE VELIGER Vol 2s Now2 later years. Such exposed places may have a greater food supply, but the young have trouble establishing themselves owing to currents and waves. With growth the larger clams are able to migrate to places with better food sup- ply (FRASER & SmiTH, 1928a, pp. 265 - 266). A similar migration may account for the distribution of larger Protothaca in our samples. Although no analyses have been made of the food of Protothaca staminea in Mugu Lagoon, SmirH (1928, pp. 288 - 291) reports that this species is a suspension feeder, collecting everything in the plankton small enough to be ingested. POPULATION CHARACTERISTICS DERIVED From EMPTY SHELLS Dead shells in our samples were about twice as numerous as live individuals, reflecting a larger time of accumula- tion compared to the time represented by the collected standing crop. There was a good correspondence between the number of left and right valves from these samples (51% and 49%, respectively) even though the ligament that holds Protothaca staminea valves together deterio- rates when they die, and the valves separate if disturbed a few weeks or months after death. Most of the discrepancy between left and right valves occurred in the smaller valves. These are more easily transported by currents and, during sampling, are more likely to break and pass through 280 240 Bees L. V.=334 WAAR. V.=327 ig Bored = 52 Valves 200 BS Number of specimens ao 4 oo 7 Age in years Figure 7 Age-frequency distribution of the left and mght valves (L. V. and R.V.) of dead Protothaca staminea, Stations 1-10, Mugu Lagoon Vol. 12; No. 2 the screen undetected. The amount of broken Protothaca shells in our samples was minimal. Commonly it is diffi- cult to ascertain if breakage is natural (by predation) or whether it occurred during the sampling process. Ideally, a dead clam would consist of left and right matching valves (LV and RV in Figures 7 and 8). A survey of the empty shells that were 2 years and older 100 80 'g 60 & YL. V.=334 H 40 AR. V.=327 2 Bored — 3 BB yeives 5? 20 10 20 30 40 Length in mm Figure 8 Size-frequency distribution of the left and right valves (L. V. and R.V.) of dead Protothaca staminea, Stations 1- 10, Mugu Lagoon indicates that most individuals are represented by corre- sponding pairs. For our purposes, the number of dead bivalves for each year or size class was derived from the maximum frequency of either left or right valves. Age and Size: Figure 7 depicts the age distribution of mortality based upon the annual rings on 661 empty valves collected in Mugu Lagoon. Most deaths occurred during or at the end of the first year of growth. In the older years, about 2 of the dead individuals collected have a winter check at the margin of the shell. This indicates a higher mortality during the winter months of decreased or non-growth, and has been observed elsewhere for other temperate-climate species (Craic & HALiam, 1963, p. 748). The size-frequency distribution of dead shells is shown in Figure 8. As was the case of the live clams collected, truncation of the smallest classes reflects the size of open- ings in the screen used as a collecting device. The first and second peaks in Figure 8 correspond to mortality of first and second year bivalves respectively. The paucity THE VELIGER Page 197 of 2- to 5-year-old individuals accounts for the low num- bers in the 20mm to 35 mm range (compare Figures 7 and 8). The peak centered around 40 mm represents a relatively greater number of dead clams which were 5 years or older upon death. Predation: The carnivorous gastropods Forreria belcheri (Hinps, 1844) and Shaskyus festivus (Hinps, 1844) have been observed preying upon Protothaca staminea and other burrowing clams in and near the channel sampled in Mugu Lagoon. About 15% of the dead P staminea sampled had been drilled by boring gastropods (Figures 7 and 8). The predator seems to be somewhat selective as to which valve it bores (34 LV and 18 RV). On the average the predators appear to select shells somewhat larger than the population mean: the mean size of 52 bored valves was 17.3 mm, whereas the approximate mean size of the remaining unbored individuals was 11.2. This apparent selection could possibly be accounted for by the chances that (1) the longer the bivalve is alive the more likely that it will be preyed upon; (2) older clams are more likely to have less resistance or be more attrac- tive (ce. g., gonad areas are preferentially drilled in some bivalves) ; and (3) a larger clam would be more likely to be encountered by a wandering gastropod. If predation were eliminated, the size classes of Figure 8 would be shifted to the right (see Craic, 1967, p. 43). POPULATION DYNAMICS Interpretations of the dynamics of modern or fossil pop- ulations derived from size-frequency distributions for shells will depend largely on the assumptions adopted regarding growth rate and mortality rate (e.g., Boucot, 1953; Otson, 1957; FacersTroM, 1964; SHELDON, 1965). The possible interactions between growth rate, mortality rate, and the other less important factors, such as seasonal recruitment of young and growth stoppages due to sea- sonality or spawning periods, make many kinds of size- frequency distributions possible in nature (Craic & OrR- TEL, 1966). Most invertebrate populations exhibit an average growth-rate curve similar to Figure 6, with rapid growth in youth and a decrease in rate with age. They also commonly produce many more offspring than can possibly survive to adulthood, and most of which die or are preyed upon as larvae or juveniles. It is necessary that only a few individuals reach sexual maturity for the population to be maintained. Page 198 Models of population dynamics usually assume morta- lity rates that decrease, increase, or remain constant with age (DEEvEy, 1947; Craic & OrrTEL, 1966; see Figure 9). Assuming that dead shells have been neither removed nor added at the site of deposition, a mortality rate for Protothaca staminea can be calculated from the age-frequency distribution of dead shells (Figure 7) and presented as a log survivorship curve (Figure 9). Our data suggest that the mortality rate for P staminea varies log survivors uw A BS A B.o ¥ Age in years Figure 9 Log survivorship curve of Protothaca staminea, based on the dead valves from Stations 1 - 10, Mugu Lagoon. Actual curve is compared to types of mortality rate generally considered in population dynam- ics: (a) increasing, (b) constant, and (c) decreasing with age in a sigmoidal fashion. The risk of death is high in the larvae and juveniles but is considerably lowered upon sexual maturity. First spawn is not until the end of the second or third year (FRASER & SMITH, 1928a; Quayte, 1943). The mortality rate does not rise again until individuals approach “old age,” forming what Com- FORT (1957, p. 221) has described as a “plateau of adult vigor.” In size-frequency distributions of accumulating shells, this pattern of mortality would be reflected by a bimodal distribution: a high peak of young individuals and a smaller secondary peak of gerontic deaths (see Figure 8). Similar patterns of mortality have been described for other mollusks (PELSENEER, 1934; ComFort, 1957). FircH (1964) reports a population of Pismo clams, Tivela stultorum, in which only 6 out of 200 live individ- uals were less than 16 years old, and in which most empty shells exceeded 5 inches (12.7 cm) in length, apparently having succumbed to old age. THE VELIGER Vol. 12; No. 2 CONCLUSIONS Boucot (1953) described two theoretical size-frequency distributions that may be of use in studying fossil popu- lations. The first is right-skewed and represents a gradual accumulation of shells of a stable population having high juvenile mortality. Except for the secondary “old age” peak exhibited by Protothaca staminea, the right-skewed curve of Boucor and our Figure 8 are similar. Another curve, approximating a “normal” or bell-shaped curve, would theoretically result from current sorting or selective destruction of empty shells by physical or diagenetic processes (Boucot, op. cit.; see discussion by HALLAM, 1967). In relatively quiet-water locations, such as the part of Mugu Lagoon where our samples were collected, intense reworking of dead shells by physical forces would not be expected (WarMeE, 1969), and the bell-shaped size-frequency distribution was in fact not realized for the empty shells. In comparison, some samples of live Protothaca stami- nea collected by FRASER & SMITH (1928a, pp. 258 - 260) are right-skewed or left-skewed, and some show a nearly normal distribution, depending upon environmental con- ditions, such as wave exposure and tidal currents. In Mugu Lagoon, deep-burrowing bivalves such as Tresus nuttalli (Conrab, 1837) live in patches where most specimens are of the same year class, giving a normal size-frequency curve for each patch. A normal distribution can also be approximated if there is a low mortality in the settled young, as reported by Craic « Hattam (1963, p. 737) for a population of Mytilus edulis Linnazus, 1758. These examples suggest that size-frequency distribution of live bivalve populations can vary greatly under a wide range of ecological and environmental conditions. A nor- mal distribution does not necessarily indicate a post- mortem process working on the shells. However, it is the mortality rate that has the ultimate influence on age and size distributions of accumulating shells that are potentially preservable as fossil populations. Data concerning this vital statistic are rarely available and, in the case of fossil populations, only attainable in- directly. In our example, the size-frequency distribution of empty Protothaca staminea shells in Mugu Lagoon in- dicates that juvenile and gerontic deaths are most fre- quent. The living standing crop, on the other hand, contains a proportionately significant number of young adults. It would appear that the death rate decreases upon sexual maturity and does not rise until old age. An interpretation of population dynamics depends upon some means of determining age and growth rate, such as Vol. 12; No. 2 THE VELIGER Page 199 growth-ring analysis. In addition, the empty shells yield significant information concerning the distribution of mortality that cannot be obtained from the live individ- uals alone. An examination of age structures for both the live individuals and the accumulating dead shells provides an integral picture of the population dynamics of the species under study. ACKNOWLEDGMENTS We express sincere gratitude to Dr. E. W. Fager, Scripps Institution of Oceanography, University of California, San Diego, for helpful criticism of the manuscript; however, we are solely responsible for the content of this paper. We wish to thank the U.S. Navy for access to Mugu Lagoon. Margaret Rogers Schmidt drew the text figures accom- panying this paper. LITERATURE CITED Bovucot, ARTHUR J. 1953. Life and death assemblages among fossils. Journ. Sci. 251 (1): 25-40; 11 figs. Comrort, ALEXANDER 1957. The duration of life in molluscs. London 32 (6) : 219 - 241; 2 figs. Craic, Gorpon Y. Amer. Proc. Malacol. Soc. 1967. — Size-frequency distributions of living and dead popula- tions of pelecypods from Bimini, Bahamas. B. W.I. Geol. 75 (1): 34-45; 12 figs. Craic, Gorpon Y. « A. HaLLaM 1963. Size-frequency and growth-ring analyses of Mytilus edulis and Cardium edule, and their palaeoecological significance. Palaeontol. 6 (4): 731-750; 10 figs. Craic, Gorpon Y. « GERHARD OERTEL Journ. 1966. | Deterministic models of living and fossil populations of animals. Quart. Journ. Geol. Soc. London 122: 315 - 355; 19 figs. DeEvey, Epwarp S. 1947. Life tables for natural populations of animals. Rev. Biol. 22 (4): 283-314; 9 figs. Quart. FAGERSTROM, J. A. 1964. Fossil communities in paleoecology: their recognition and significance. Bull. Geol. Soc. Amer. 75 (12): 1197 to 1216; 5 figs. Fitcu, JoHN Epcar 1965. A relatively unexploited population of Pismo clams, Tivela stultorum (MaweE, 1823) (Veneridae). Proc. Mala- col. Soc. London 36 (5): 309 - 312; plt. 13 Fraser, C. McLean & Gertrupe M. SMITH 1928a. Notes on the ecology of the little neck clam, Paphia staminea CONRAD. Trans. Roy. Soc. Canada 22 (5): 249 to 269; 2 figs.; 5 plts. 1928b. Notes on the ecology of the butter clam, Saxidomus gigantcus DESHAYEs. ‘lrans. Roy. Soc. Canada 22 (5): 271 - 286; 2 plts. Hata, A. 1967. ‘The interpretation of size-frequency distributions in mol- luscan death assemblages. Palaeontol. 10(1): 25-42; 11 figs. Oxson, Everett C. 1957. Size-frequency distributions in samples of extinct or- ganisms. Journ. Geol. 65 (3); 309 - 333; 17 figs. Orton, Joun H, 1926. On the rate of growth of Cardium edule. Part. 1. Experimental observations. Journ. Mar. Biol. Assoc. U. K. 14; 239-279; 12 figs. PELSENEER, PAUL 1934. La durée de la vie et l’age de la maturité sexuelle chez certains mollusques. Ann. Soc. Zool. Belg. 64: 93 - 104; 1 fig. Quayte, DaniEL BRANCH 1943. | Sex, gonad development and seasonal gonad changes in Paphia staminea Conran. 6 (2): 140-151; 5 figs. SHELDON, RaymMonp W. 1965. Fossil communities with multi-modal size-frequency distributions. Nature 206 (4991): 1336 - 1338; 6 figs. SmitH, GERTRUDE M. 1928. Food material as a factor in growth rate of some Pacific clams. Trans. Roy. Soc. Canada 22 (5): 287 - 291 WarME, JOHN E. 1966. — Paleoecological aspects of the Recent ecology of Mugu Lagoon, California. Ph. D. dissertation, Univ. Calif. at Los Angeles: 380 pp.; 41 figs.; 5 plts. 1969. Live and dead molluscs in a coastal lagoon. Paleontol. 43 (1): 141-150; 2 figs. WEYMOUTH, FRANK W. 1923. The life-history and growth of the Pismo clam (Tivela stultorum Mawe). Fish. Bull., Calif. State Fish & Game Comm. 7: 120 pp.; 15 figs. Journ. Fish. Res. Brd. Canada Journ. Page 200 THE VELIGER Vol. 12; No. 2 Mimicry of the Gastropod Mitrella carinata by the Amphipod Pleustes platypa JULES M. CRANE, Jr. Cerritos College, Norwalk, California 90650 (Plate 36) THE PLEUSTID AMPHIPOD, Pleustes platypa BARNARD & Given, 1960, was described on the basis of 3 preserved specimens collected off Palos Verdes, Los Angeles County, California (BARNARD & GivEN, 1960, pp. 41 - 42; fig. 1). Because preserved specimens rapidly lose their color and have their appendages in unnatural positions, it was not apparent that in life these amphipods look remarkably like the snail Mitrella carinata (Hinps, 1844). In May, 1966 a single living specimen of P. platypa was discovered on the kelp Macrocystis pyrifera by the Cerritos College Marine Biology class near Point Loma, San Diego, Cali- fornia. Collected as Mitrella carinata, the amphipod char- acteristic was not observed until much later when the collection was examined in the laboratory. Because of the uncertainty about the maintainance of this specimen alive, it was observed briefly and then preserved. When it became apparent that this was the only known arthropod molluscan-mimic, efforts were made to obtain more specimens for observation and photography. Finally, on September 17, 1968, 5 living specimens were collected from a Macrocystis holdfast floating at a depth of 15 feet off Point Dume, Los Angeles County, California. These were photographed the same day using randomly collected specimens of Mitrella carinata for comparison (Plate 36). Pleustes platypa tucks its pleon up under the pereon where it is shielded from view by the enlarged and flat- tened protopodites of the 6", 7", and 8" pereonal (tho- racic) appendages and the enlarged coxal (lateral) plates of the pereon. The 2 pairs of gnathopods are similarly hidden by the coxal plates. The amphipod rests at about a 30° angle, supported by the 6", 7", and 8" pereopods, which also serve as locomotor structures in this position. These appendages permit the amphipod to crawl slowly or launch rapidly into darting, short-distance swimming activity. The amphipod coloration is highly variable, as is the coloration in Mitrella. Both specimens shown in Plate 36 have similar color patterns. This particular amphipod had a dark grey cephalon, a yellow band around the anterior half of the pereon, and graded from light brown to dark brown posteriorly. The pereopods (walking legs) often display light and dark grey or brown bands which mimic the mottling found in the foot, siphon, and eye stalks of Mitrella. These are contrasted with the darker coloration of the protopodites. Judging by skin divers’ reports and recorded captures, Pleustes platypa appears to be rare but this is probably because of the difficulty in distinguishing it from the extremely abundant Mitrella carinata. All specimens have been found in association with Macrocystis. The presently known range of P platypa is herein reported as Point Loma, San Diego, California to Gaviota Beach, Santa Barbara County, California. A single observation of an- other as yet unidentified species of amphipod mimicking a different form of Mitrella carinata found in pholad holes in cobble off Point Loma, California, suggests that the whole range of polymorphism in Mitrella may be reflected in mitrelliform amphipods. ACKNOWLEDGMENTS I wish to thank Dr. Rimmon Fay, president, Pacific Bio- marine Company, for providing the live specimens; Dr. J. L. Bamard, U.S. National Museum, for the identifi- cation of the initial specimen; and Robert L. Eberhardt, Lockheed Aircraft Corporation, for cooperation in the use of the RV Sea Quest. The photograph of the living animals was taken by George Reeves. LITERATURE CITED BarNARD, J. LAURENS & Ropert R. GIVEN 1960. Common pleustid amphipods of southern California, with a projected revision of the family. Pacif. Naturalist 1 (17): 41-42; 1 text fig. (15 April 1960) Tue VELIcER, Vol. 12, No. 2 [CRANE] Plate 36 Mitrella carinata (left) showing mimicry by the amphipod Pleustes platypa (right) i Vol. 12; No. 2 THE VELIGER Page 201 Cypraeidae of the Red Sea at Massawa, Ethiopia, with a Zoogeographical Analysis based on the Scuitpers’ Regional Lists BY T. C. FOIN Institute of Ecology, Environmental Systems Group, University of California, Davis, Davis, California 95616 AND L. P RUEBUSH Box 67 USA STRATCOM Fac., Asmara, APO New York 09843 (3 Text figures; 1 Table) BECAUSE OF THE INTERESTS Of shell collectors, the genus Cypraea has been the subject of an expansive literature, including many lists of species from various faunal prov- inces, To our knowledge no list of Cypraea from the Red Sea since the compilation of ScHILDER & ScHILDER (1938- 1939) has been published, however, despite the interesting species that have resulted from the isolation of the Red Sea from the remainder of the Indian Ocean basin. The SCHILDER & SCHILDER records were based on literature records, and many of their recorded species require con- firmation. This paper represents several years of collecting by the junior author in the southern Red Sea, and is a compilation of the species found in the area with a com- parison to other Indian Ocean species. The Massawa Area Massawa, Ethiopia, is located at approximately 39°29’ E Latitude and 15°39’ N Longitude on the western shore of the Red Sea. The Dahlak Archipelago completely shields Massawa from the open sea to the east, but Massawa is an important port because of the two channels that pene- trate the Dahlak Archipelago from the north and the south. The remainder of the area is shallow and generally does not exceed 5 fathoms in depth. Cypraea spp. are found in many habitats, ranging from mudflats to coral reefs; some species are accessible intertidally, but most are obtainable only by diving. Most collections were made in this manner. Collections were made in all seasons; the only notable changes in species abundance occur in the winter months, when it is assumed that many individuals either hide and are inactive, or migrate to deeper water. tomical studies in this paper are limited to color obser- All measurements were taken with vernier calipers; ana- vations and gross detail of external structures. A map of the collecting area is presented in Figure 1. Cypraea of the Southern Red Sea Cypraea annulus LinNAEuS, 1758 This species is very common in the low intertidal and shallow subtidal zones, restricted to areas of old coral and rock rubble possessing strong currents. Shell form is in agreement with that given by Orr (1959) for Cypraea annulus from similar habitats off Zanzibar. Cypraea arabica LinNAEus, 1758 (Cypraea grayana ScHILDER, 1930) This species is widespread over both the habitat in which Cypraea annulus is found and in living coral. Specimens appear to be more abundant in the former habitat. All specimens found have been small for the species, averaging about 30 mm. Cypraea arabica is one of the most variable Page 202 39° 30" 40’ Daret Island 4 4. \, Dehel Island 50 Ras el Garara C Massawa Sheikh Said Island a7 Ras Gedem oles Gedem Mountain 34 30 Eritrea Gulf of Zula 15°90’ THE VELIGER Dissei Island p Dur Ghella Island Q ce . Dur Gaarn Island rts) Ras Arb g, » Nocra Island Ghubbet Mus Nefit a Enteara Island o Madote Island Buri Peninsula ©." = a fo) 10 Figure 1 Map of the Massawa, Ethiopia area, including a part of the Dahlak Archipelago Adapted from a U.S. Army Map Service chart made in 1936 species found in the Massawa area; specimens may be found that resemble C. grayana, C. eglantina Ductos, 1833, and C. arabica. The diagnosis given by SCHILDER & SCHILDER in their prodrome for C. grayana emphasizes a subpyriform, often humped shape, reticulate or dilacerate dorsal pattern, and a spire blotch. The ScuitpErs and CrernoHorsky (1964) diagnose C. eglantina as having a cylindrical shape, unmargined sides, a spire blotch, and a dorsal pattern of longitudinal lines interrupted by pale lacunae. Cypraea arabica is said to differ from these 2 species by the lack of a spire blotch, its hieroglyphic dorsal pattern, ovate shape, and the heavily margined sides. Our analysis of the Massawa “arabica” (Figure 2) of the above characters is based on a classification of each shell Vol: 12;3Now2 20 miles Vol. 12; No. 2 with respect to the base, dorsum, shape, and spire blotch. In the logical tree only the combinations found of the 36 possible are presented. Only one of the sample (N = 19) examined was a C. grayana and 3 were C. arabica; Spire Blotch Base Shape Pattern No. Specimens rp margined —— subpyriform — reticulate I present Lrounded — subpyriform — reticulate 1 (= grayana) hieroglyphic 3 (= arabica) ovate — longitudinal 3 reticulate I eon hieroglyphic 2 Schley ae longitudinal 4 absent — pa cylindrical — hieroglyphic 2 rounded | subpyriform — hieroglyphic Nn Figure 2 Distribution of shell characters of a sample of “Cypraea arabica” from Massawa of the remainder, all but one most closely resembled C. arabica. We have, therefore, provisionally called the Mas- sawa specimens C. arabica instead of C. grayana. This analysis also suggests that a reexamination of the group of species in the “arabica” complex may be warranted. Cypraea camelopardalis Perry, 1811 Cypraea camelopardalis is relatively common throughout the region on and under coral reefs. This species is the most variable local species in size and pattern; the smallest adults range down to 35mm, while the largest exceed 70mm. The dorsum is frequently heavily scarred. Two adult patterns may be distinguished: the normal pattern, with white spots scattered over the dorsum; and individ- uals ranging from a few white spots to none at all. These differences are assumed to be both genetic and environ- mental, but since all combinations have been found to- gether, these patterns are thought to bear no taxonomic significance. The color of the external anatomy of C. camelopardalis is the same as in C. vitellus LINNAEUS, 1758, as described by CeRNoHorSKY (1964); this is further evidence of the supposed close relationship of the two species. THE VELIGER Page 203 Cypraea carneola LINNAEUS, 1758 Cypraea carneola, like C. annulus, is restricted to areas of rock and coral rubble swept by strong tides and currents, but may be locally abundant in these places. All species found in these areas have been characterized by small size; C’. carneola is no exception. Specimens average about 25 mm in size. The dorsum normally is heavily scarred. Conchologically, anatomically, and ecologically, speci- mens found in the Massawa area closely resemble typical C. carneola from the Indo-Pacific. Cypraea caurica LINNAEUS, 1758 C'ypraea caurica may be locally common, although like C. carneola, it is restricted to specific habitats. In the Massa- wa area the species is usually found under isolated coral heads, either living or dead. The species is quite variable in size, in labial denticles, and in the presence or absence of a dorsal blotch, but all specimens are easily recognized as C’. caurica. The nominal subspecies C’. c. quinquefas- ciata Born, 1778, inhabits the Red Sea. We have not evaluated the validity of this name. Cypraca clandestina LINNAEUS, 1767 A single living specimen of this species has been found under a rock off Dissci Island, SE of Massawa near the Gulf of Zula. Beach specimens are similarly very rare; we infer that either this species does not normally occur in the Massawa area or is very rare there. Cypraea erosa nebrites MELvILL, 1888 In the Massawa area individuals of Cypraea erosa neb- rites are mostly restricted to the islands, largely in areas of isolated living coral and rock rubble, although a few have been found on the mainland at Ras El Garara. Cypraea e. nebrites is easily recognized: the marginal blot- ches are always prominent, do not extend unto the base, the teeth are distant and streaked with red, and the shell is more rounded and compact than Indo-Pacific C’. erosa Linnaeus, 1758. The animal also differs in color from Fijian examples: there is a predominance of green in the mantle lobes and siphon. Cypraea e. nebrites is relatively common, but Massawa examples are smaller than those from more northerly localities. Cypraea exusta SOwERBY, 1832 Cypraea exusta is restricted to the NW Indian Ocean and is very rare in the Red Sea. Only 5 specimens have been found, all together, under a coral head in the south Page 204 harbor of Massawa. Specimens are easily distinguished from C. talpa Linnaeus by the less expanded base, the more rotund shape, the extremely dark coloration, and the very fine and numerous columellar teeth. It is possible that C. exusta is a rare subspecies of C. talpa; at least, they are sibling species. Cypraea felina GMEun, 1791 Cypraea felina is one of the more common species in the Massawa area; it may be found in rocky habitats, usually in association with C, annulus, C. arabica, C. carneola, and C. caurica. This species is not very variable in size or shape. Length-breadth-height measurements comparisons with C, f. fabula Krener, 1843, from the Arabian Gulf and C. f. felina of East Africa indicate that the Red Sea subspecies is probably the latter. Cypraea gracilis notata Giti, 1858 This species is common in the same habitats as Cypraea felina. It occurs in two distinct shapes, one more cylind- rical, the other pyriform. These forms may be found to- gether, and no ecological significance has been attached to this difference. The colors of the living animal feature a white mantle, orange foot and head, and black eyes. Average lengths of the Massawa individuals range from 13 to 16 mm. Cypraca isabella LinNAEuS, 1758 Only a single example of Cypraea isabella has been found living in the Massawa area (South Harbor). This species does not normally appear to occur in the area. Cypraea lentiginosa Gray, 1825 Cypraea lentiginosa is occasionally in the Dahlak Archi- pelago but very rarely along the mainland. One was found in the South Harbor. It is apparently a recent immigrant to the Red Sea; ScHILDER & ScHILDER (1938-1939) list its center of distribution as the waters between the Gulf of Oman and the Indian subcontinent. Cypraea lynx Linnagus, 1758 This species is occasionally found in the offshore islands but rarely along the mainland. It occurs in the same hab- itats in which Cypraea camelopardalis and C. pantherina Licutroot, 1786, are found. The species is said to be represented in the Red Sea by the subspecies C. 1. williamsi Me vii, 1888. The ScuitpeErs give a diagnosis for C.l. williamsi; they cite a short anterior terminal ridge, blunt posterior extremities, rounded sides, obsolete basal carinae, wide aperture, and a pink base. Base color cannot be THE VELIGER Vol. 12; No. 2 used as a subspecies criterion in this case, as C. lynx with pink bases may be found haphazardly over the Pacific and Indian Ocean basins, in all the other nominal subspecies. Individuals of C’. lynx from various localities in the Indo- Pacific also show the characteristics of C. J. williamsi; we feel that C. /. willamsi is not a valid subspecies, but this conclusion needs confirmation. Cypraea pantherina Licutroot, 1786 Cypraea pantherina is one of the most common and con- spicuous cowries of the Red Sea. It is widespread over the region but is restricted to areas of coral development. This species exhibits considerable variation in dorsum colora- tion, from nearly pure white with few spots, to nearly all black. There are also stages of development of a goiden color form, which at its most extreme stage appears as a solid golden brown (funebralis SuLuorti, 1924). In many specimens the golden nacre is succeeded by a pattern of black spots over white; the golden color persists as the dorsal line. If this is also true for the darkest specimens, the color may persist for less than the lifespan of an individual. A large series of C. pantherina demonstrates the intergradation in color that occurs; under these cir- cumstances the name funebralis is no more than the name of a specific color form, one which may last for less than the adult life of an individual. Accordingly, it is probably inappropriate that even the informal taxon forma should be used for funebralis, and the name should be dropped. Cypraea pulchra Gray, 1824 This species is found in coral in the Massawa area. The individuals encountered are easily recognizable, as there is almost no variation shown by the species, other than in size. Cypraea staphylaea LinnagEus, 1758 A few beach specimens of this Indo-Pacific species have been found, but no living examples are known from Massawa. Cypraea stolida erythraeensis SowERBY, 1837 Cypraea stolida erythraeensis is restricted to coral reefs on the offshore islands, although it occasionally occurs on the mainland. This subspecies is considerably smaller than the other subspecies of C. stolida; it averages only about 18mm in length. Specimens are characterized by a plain white base with teeth produced and a large, often isolated, dor- sal blotch. Cypraea s. erythraeensis appears to be quite invariable except for the form and dimensions of the dorsal blotch. Tooth color is also said to be variable (R. H. r Vol. 12; No. 2 Summers, personal communication). The ScHILDERs ac- cord specific status to C. s. erythraeensis. Cypraea turdus LAMaRcK, 1810 Cypraea turdus is frequently found in company with other species inhabiting areas of isolated rock and coral and possessing strong tidal surges and currents. There is considerable size variation, although all specimens seen have been quite broad. An occasional specimen will be nearly all white as the result of very extensive lateral callouses. This species appears to be the most widespread and common of the Massawa Cypraeidae. The ScuiLpers’ list includes several species that have not been found in the Massawa area. These are C'ypraea cicercula LinNAEUS, 1758, C. macandrewi SOWERBY, 1870, C. nucleus Linnagus, 1758, C. helvola LINNAEUS, 1758, C. teuleri CAZENAVETTE, 1846, C. talpa LINNAE- us, 1758, C. mappa LinnaEus, 1758, and C. mauritiana LinnaEus, 1758. Of these, the ScHi~pERs expressed doubt about validity of the C. talpa and C. mauri- tiana records; because these are large and normally common species, we are inclined to agree. We also do not belicve that C’. moncta occurs in the Massawa area. Some recent collections of C’. nucleus, C. macandrewi, C. cicercula, and C. gangranosa have been reported from the Red Sea (R. H. Summers, personal communication). We infer that all these species are rarely collected in the Massawa area. We have no information concerning C. mappa, C. helvola, or C. teulerei, although we have received one unconfirmed report on the former species. Zoogeographical Implications of the Red Sea Cypraea The British Navy Intelligence Division (1946) has sum- marized the geological history of the Red Sea basin. The Red Sea is a shallow, warm-water, marginal sea of the Indian Ocean formed by the flooding of part of the East African rift valley around the Pliocene. Shortly thereafter, the Red Sea and the Gulf of Aden were connected to the Indian Ocean, and the main northward flow through the narrow strait (Bab-el-Mandeb) that marks the mouth of the Red Sea was established. One would expect that the recent origin and isolation of the Red Sea would have marked effects on the cypraeid fauna. Eighteen species are listed from Massawa in this paper, of which 5 are endemic to the Erythraean region. When the regional lists of ScHILDER & SCHILDER (1938-1939) were analyzed and doubtful taxa removed, the Erythrae- an province clearly had a greater proportion of endemic THE VELIGER Page 205 species than any other province of the Indian Ocean (Table 1). We removed doubtful records and lumped all Table 1 Reduced number of species and proportion of endemic species in regions of the Indian Ocean Number Number of species endemic Northern Red Sea 19 8 Central Red Sea 24 9 Southern Red Sea 37 10 Gulf of Aden 42 10 Chagos Archipelago 43 1 Mauritius 49 1 St. Francis Bay to East London 27 6 Zanzibar 40 0 “sympatric subspecies” into a single species for these an- alyses. Our records generally agree with the ScHILDERs’ list, and are evidence of the isolation of the Erythraean region from the remainder of the Indian Ocean. We feel, therefore, that the ScuILpeErs’ lists are sufficient for zoo- geographical analysis. The cypraeid fauna is also depau- perate in comparison to the remainder of the Indian Ocean, but the total number of C'ypraea species is similar to that of the South African region. Isolation has pro- duced several nominal subspecies — nebrites, erythrae- ensis, and notata — and 3 species — camelopardalis, exusta, and pantherina. These 3 species are easily derived as sibling species from 3 common Indo-Pacific ones. These are Cypraea vitellus, C. talpa, and C. tigris, respectively. When the reduced number of species in the SCHILDERs’ lists for the Erythraean region are plotted against distance of the midpoint of the length of the eastern Erythraean region (Gulf of Aden), Figure 3 results. When plotted as a semilog or log-log function, the points more nearly fall in a straight line, but a distinct inflection remains in the curve. Two explanations are possible: either there are more species in the Red Sea than can be accounted for as a simple function of distance, or the Gulf of Aden is depauperate. The latter explanation is unlikely as the reduced number of species reported (43) compares with the main basin of the Indian Ocean (Table 1). The first report of Cypraea clandestina, C. gangranosa, and C. lentiginosa from Massawa, and the increasing propor- tion of regionally endemic species in a northward direc- tion through the Red Sea, are evidence that species char- acteristic of other Indian Ocean provinces are still enter- ing the Red Sea, and that given sufficient time the number Page 206 50 40 30 Number of Species 20 500 1000 1500 2000 Distance from Midrange of Gulf of Aden Figure 3 Decreases in number of species as a function of distance from the NW Indian Ocean to the Gulf of Suez, from the ScHILDER & SCHILDER lists of species in the Red Sea should equilibrate with the rest of the Indian Ocean. We interpret the inflection in the curve of Figure 3, and the number of new species found at Massawa, to mean that Bab-el-Mandeb is not an effective barrier to species immigrating from the Gulf of Aden into the Red Sea, at least at present. The presence of at least 6 sibling species and subspecies implies that the Red Sea was either formerly more isolated or that immigration of a particular new species into the Red Sea has been sporadic and infrequent. We cannot now differentiate between these. THE VELIGER Vol. 12; No. 2 SUMMARY (1) Eighteen species have been found in the Massawa, Ethiopia area of the 27 reported by ScHILDER & ScHIL- DER (1938-1939) list. Four of the 9 species remaining to be collected are probably present but rare, and 3 are probably erroneous reports. (2) The Massawa Cypraeidae contain a high percentage of regionally endemic forms (8 of 18), but 6 of these are easily derived from widespread Indo-Pacific species. (3) The number of endemic forms and the number of Cypraea species indicate that the Red Sea was at least at one time highly isolated from the remainder of the Indian Ocean. (4) Analyses of several nominal subspecies from the Mas- sawa area and of the ScHILDER & SCHILDER lists suggest that gene flow within the Cypraeidae may be wide- spread. LITERATURE CITED CERNOHORSKY, WALTER OLIVER 1964. The Cypraeidae of Fiji (Mollusca:Gastropoda). The Veliger 6 (4): 177-201; plts. 21-26; 1 Text fig.; 1 map (1 April 1964) NavaL INTELLIGENCE Division, Royat Navy, GREAT BRITAIN 1946. | Western Arabia and the Red Sea. Geograph. Hand- book Ser. 527 Orr, VIRGINIA 1959. A bionomic shell study of Monetaria annulus (Gastro- poda : Cypraeidae) from Zanzibar. Notul. Natur. 313 ScHILDER, FRANZ ALFRED 1962. Hybrids between Cypraea tigris Linnarus, 1758 and Cypraea pantherina SoLANDER, 1786. The Veliger 5 (2): 83 - 87, 1 diagram. (1 Oct. 1962) SCHILDER, FRANZ ALFRED, & MARIA SCHILDER 1938 - 1939. Prodrome of a monograph on living Cypraeidae. Proc. Malacol. Soc. London, 23 (3): 119-180; (1939) 23 (4): 181 - 231; 1 text fig.; 9 maps. (15 November 1938 and 15 March, 1939) Vol. 12; No. 2 THE VELIGER Page 207 The Distribution and Ecology of Sub-Littoral Species of Macoma (Bivalvia) off Moresby Island and in Satellite Channel, near Victoria, British Columbia R. M. DUNNILL AND D. V. ELLIS Department of Biology, University of Victoria, Victoria, British Columbia, Canada (9 Text figures; 3 Tables) INTRODUCTION THE GENUS Macoma Leacu, 1819 (Bivalvia) is widely distributed in northern seas and is also known to occur south of the equator in East Africa (THorson, 1957, p. 106). It has undergone wide speciation, particularly in the eastern North Pacific and DUNNILL & Etuts (1969) have confirmed 13 species presently occurring in the shal- low coastal waters of southern British Columbia. Previous ecological studies (and incidental mention) of Macoma in the eastern North Pacific have in general been con- fined to the littoral species MM. inquinata (DESHAYES, 1854), M. nasuta (Conran, 1837), M. secta (Conran, 1837), (amongst others, SHELFORD & Tow er, 1925; SHELFORD et al., 1935; MacGrnitic, 1935; AppicotTT, 1952). The dearth of detailed ecological studies on sub- littoral species of Macoma probably stems from earlier confusion over the taxonomy of the genus. This paper discusses the distribution of 8 species of Macoma occurring sub-littorally in an area of predomi- nantly sandy sediments off the north end of Moresby Island, near Victoria, British Columbia, and examines the effects of some environmental factors. Data from a previous benthic survey in adjacent Sat- ellite Channel by Etxis (1967 and in press) are included since this extends the range of sediment types covered. ' Based on part of a thesis submitted by R. M. Dunnill in partial fulfillment of the requirements for the degree of M. Sc. at the University of Victoria ACKNOWLEDGMENTS We wish to thank F Bernard, J. Dobrocky, R. Herlinveaux, D. B. Quayle, R. G. B. Reid, and D. Thorndick for their assistance in various aspects of this study. Federal Government vessels were made available for the surveys through the Canadian Committee on Oceano- graphy. The investigations were financed by the National Mu- seum of Canada, the National Research Council of Cana- da, the Defence Research Board and the University of Victoria. DESCRIPTION or tHE STUDY AREA PHYSIOGRAPHY Satellite Channel, on the south-western fringe of the Strait of Georgia, southern British Columbia (Figures 1 and 2) is roughly 13 nautical miles long, 1.5 to 2.0 nautical miles wide and has a mean depth of 73m, although in several places, narrow elongated zones occur with depths greater than 90m. Oceanic water has access to Satellite Channel from Swanson Channel and Haro Strait over a sill at a depth of 66m. Moresby Island lies at the east end of Satellite Channel at its junction with Swanson Channel. Page 208 THE VELIGER ™ Gulf Islands ~ WY Gyn Riya Satellite Channel San Juany ee Op Figure 1 @ Hydrographic Station \ e Anchor Dredge 4 Van Veen _ Time Series 0 1 2 Nautical Miles s 123°30’W Figure 2 Satellite Channel and Moresby Island showing station localities a amas 123°20° Vol. 12; No. 2 Vol. 12; No. 2 HYDROGRAPHY Tuxtty & Dopimeap (1957) and WatpicHuk (1957) discuss the oceanography of the Strait of Georgia. According to WALDICHUK (op. cit.), there are basically 3 water masses in the Strait of Georgia-San Juan system: 1. the brackish surface water from run-off in the Strait of Georgia (mainly from the Fraser River) ; 2. the deep water of oceanic origin in Juan de Fuca Strait; and 3. a mixture of (1) and (2) which forms at the sills between the straits. Tidal currents in the southern region of Georgia Strait flow rapidly and turbulently in narrow passages between mazes of islands (TuLty « Dopimeap, 1957). Intensive March 31 1959 June 8 1959 November 16 1959 Station B B E Temperature °C pent 9 iowa a2 8 10 25 50 | | 75 | Salinity % 026 28 30 29 31 27 Depth in meters w =) Dissolved Oxygen (m1/1!) 4 6 8 50 75 Figure 3 Water properties in Satellite Channel THE VELIGER Page 209 tidal action, aided by wind and waves, particularly in winter, mixes the brackish surface layer with underlying more saline water to near homogeneity. Temperature and salinity stratification is minimal in the channels of the southern Strait. In Satellite Channel, in the northwestern portion of the southern region, current velocities are lower, there is less mixing and more stratification develops. Seasonal changes in properties of the upper 75 - 80 m of the water column in Satellite Channel are shown in Figure 3, based on data from HERLINVEAUX et al. (1960) and Pacific Oceano- graphic Group (1959a and 1959b). A pronounced thermocline, established in summer, is destroyed by increased mixing in winter. The deeper water averages about one degree Centigrade lower in winter than in summer. Salinity changes mainly reflect the seasonal cycles of run-off of the Cowichan River (HERLINVEAUX, 1962). A prominent halocline develops in the upper 10 m in winter and spring, coinciding with maximal annual precipitation and run-off in the area at sea level. The surface lower salinity layer is much less in evidence in summer, when discharge from the Cowichan River is low. However, a less pronounced halocline persists, possibly indicating the presence of Fraser River outflow, which is maximal in summer. From 15-85 m, temperature, salinity, and dissolved oxygen values show little seasonal or vertical variation. Temperatures range from 7.87 -9.70° C, salinities from 29.25 - 31.46%, and dissolved oxygen concentrations from 4.37-6.13 ml/l. Ranges in these properties seem too small for them to be important in limiting distribution of sub-littoral Macoma species in Satellite Channel at depths investigated. Water off the north end of Moresby Island, closer to regions of intense mixing than the hydro- graphic stations in Satellite Channel, probably is less stratified and has smaller ranges in temperature, salinity, and dissolved oxygen concentrations. Sediment tempera- tures measured off Moresby Island in the summer of 1967 (Table 1) had a range of less than 1° C at stations between 26.5 and 84.0 m. GEOLOGY Sediments in Satellite Channel and their Origins There is a marked progression in the Satellite Channel trough from very fine grained sediments at the western end near the mouth of the Cowichan River to coarser grained sediments in the east (Figure 4). The mean silt- clay fraction was 95.4% in Cowichan Bay and 82.2% at the mouth of the bay. Further east, the silt-clay fraction had decreased to 40.3% at Satellite Channel Center and Page 210 %MSilt-clay O- 25 25- 50 50- 75 75 - 100 Shell gravel #48 0 il | Nautical Miles 123°30’W THE VELIGER Vol. 12; No. 2 Figure 4 Generalized distribution of sediments in Satellite Channel to 25.9% at Satellite Channel East. Excluding stations on “shell-gravels”, the mean of the 13 stations (26 samples) on the finer sediments in the grid at the north end of Moresby Island was 31.3% silt-clay. There were localized exceptions to this main trend. Bosun Bank on the west side of Satellite Channel, near its northwestern end, was noticeably sandy (15.3% silt-clay), while Fulford Harbour near the east end had fine grained sediments (69.2% silt-clay). “Shell-gravels” occurred at 4 stations at the mouth of Moresby Passage (Figure 2), where currents reach 2 - 3 knots (Canadian Hydrographic Service, chart 3452). The fine grained sediments at the west end of Satellite Channel, in the vicinity of Cowichan Bay, probably owe their origin to material carried down in suspension by the Cowichan River. It is improbable that the coarser grained fractions of the sediments in the channel trough originate from material brought down by the Cowichan River since these would, in that case, be deposited before the fine grained material in Cowichan Bay. The sandy-silts of Fulford Harbour probably result from deposition from small streams, notably Fulford Creek. Wane (1955) indicates that away from large rivers, much of the sediment added to the inland waters is derived from the erosion of shoreline glacial till. Most of the eroded clay and silt fractions are carried out to sea by the currents, leaving bottom sediments consisting of boulders, gravel, and sand. According to WENNEKENS (1959), erosion of shoreline glacial deposits provides a considerable part of sediments in the San Juan Archipel- ago. This process is undoubtedly important in the forma- tion of bottom sediments in the Satellite Channel area also. “Shell-gravel” from the Moresby Island grid con- tained an assortment of small rocks (cobbles) of igneous, sedimentary and metamorphic origin, varying in outline from sub-rounded to sub-angular. There was also a finer matrix containing a considerable proportion of shell frag- ments and some intact dead bivalves enclosing a dark clay. It seems probable that this poorly sorted sediment results from erosion of a glacial till, possibly in situ, by selective washing out of silt and clay, leaving behind a coarser frac- tion, too heavy to be transported. In the lee of the north end of Moresby Istana there is an area relatively sheltered from the currents that sweep through Moresby Passage and Swanson Channel. The sed- iments here are predominantly sandy although the silt- clay fraction of 26 samples varies from 14 to 46%. The bathymetry of this locale suggests eddies may build up when tidal currents reach their peak in the adjacent pas- sages, carrying in and depositing material from suspension Vol. 12; No. 2 in a haphazard fashion. The bottom of this sedimentary bank slopes down to the channel trough more slowly than the bottom in the exposed areas of Swanson Channel, to the east. Dense bivalve populations, including large a- dults, whose growth rings show they are 8 or more years old, indicate the sediments of the bank are relatively stable. METHODS A grid of stations was established off the north end of Moresby Island and sampled in the summer of 1967. A 0.1m? Van Veen grab, tried initially, would not work on “shell-gravels” and was replaced with a 52.0 1 capacity anchor dredge, based on that in Hotme (1964). The anchor dredge was backed by a steel plate instead of a net, preventing “washing-out” of the sample, except at the bucket surface. Two samples were taken at each station and sample sizes ranged from 28.8 to 52.01 (Table 1a, 1b). The dredge, when weighted as in Figure 5, was estimated to penetrate to a mean depth of 7.5cm. Since sample volumes were known, approximate sample areas could be estimated. In the Satellite Channel survey, 10 to 16 samples were taken at each station using 0.1 and 0.2m” Van Veen grabs (Table 1c). Figure 5 The weighted anchor dredge THE VELIGER Page 211 Sediment samples were taken for particle analysis by a modification of the hydrometer technique of Bouyoucos (1951) and data are recorded in Table 1. After sample temperatures and volumes were measured, the entire samples were washed through a 2 mm square mesh wire screen and all macrobenthos picked out and preserved in 10% neutral formalin. Macoma count and weight data are recorded in DunniLx (1968) and are shown graphic- ally in Figures 6 and 7. The “average size” of a population of a given species (the ratio of wet weight to number of individuals per meter squared), assuming the full size range of the species at that locality is sampled, is of some value as an indicator of environmental suitability. Where “average size” is rela- tively high for a species, the environment must be suffi- ciently favourable to allow continued survival of individ- uals to a (relatively) large size. Where “average sizes” at a given locality are very small, first impressions are that environmental conditions there are unfavourable to the species, which is either failing to survive to a large size (i. e., is very short lived) or has a very slow growth rate. However, the investigator might be sampling a young pop- ulation in a favourable environment. Counting growth rings would show the actual age of the population. A second sampling of a young population after the lapse of a year or two would indicate whether or not that popula- tion of the species was surviving and environmental con- ditions were favourable. Successful migration of adult specimens of Macoma over any appreciable distance would seem unlikely, at least in Satellite Channel, since the area supports con- siderable numbers of bottom fish. RESULTS Macoma in Relation to the Physical Environment Eight species of Macoma were found sub-littorally on the Moresby Island: grid and two additional species, M. in- quinata and M. nasuta, were found intertidally at the north end of the island. Thus at least 10 of the 13 species found in southern British Columbia (DUNNILL & ELLIs, 1969) occur within a very small area at the north end of Moresby Island. Macoma inquinata and M. nasuta are both shallow water species in the study area and were not found in grab or dredge samples either off Moresby Island or in Satellite Channel. They will not be considered further in this study. Macoma yoldiformis CarPENTER, 1864 was found at a single location, station 19 (29 m, 25.0% silt-clay) . Accord- ding to Bernarp (1967), the species ranges from inter- tidal to 18 m in British Columbia. It was found in Sooke Page 212 THE VELIGER Vol. 12; No. 2 Table 1 Station List, Sample Sizes, Sample Areas and Environmental Data (a) Moresby Island grid - excluding stations on “shell-gravel” : : 6) S gD z § g a ag Ba 3 qe n QA n 23) q ae SS 1 80 52.0 0.69 - 38.0 6 65 52.0 0.69 - 23.0 10 73.5 45.6 0.60 - 41.5 11 55.5 46.5 0.62 9.8 14.0 13 35.5 37.5 0.50 9.9 29.0 14 26.5 41.1 0.55 10.1 32.0 15 77.5 52.0 0.69 - 39.5 16 62.5 44.8 0.60 9.5 32.0 17 53.5 40.2 0.54 9.6 36.0 19 29.0 52.0 0.69 9.9 25.0 20 85.0 52.0 0.69 - 22.5 21 84.0 44.8 0.60 9.4 32.0 22 74.0 44.8 0.60 9.9 45.5 (b) Moresby Island grid - stations on “shell-gravel” 5 — = a iS a g Sy 7 eS & gS = 2 its} Si g g c= 2. 2a. = if Ss 3 5 ae ss S n QA n rea} 6 ne Ss 2 55.0 49.2 0.65 10.0 42.0: 4 33.5 34.9 0.46 = 34.5 7 BLS) 52.0 0.69 9.5 43.0: 9 40.5 44.7 0.59 9.8 37.5% " % silt-elay in sediment fraction passing a 2 mm screen (c) Satellite Channel € Ss of 3 z = oS eee ues 3 3 a. & 6 oz s Station a =| 3 g 33 ig A n ne FQ 2 S FE (Fulford Harbour) 22.7 33.9! - - 69.2 CEN (Satellite Channel Center) 74.5 10.0 8.3-9.2 29.40-32.48 40.4 XS (Cross Section South) 9.0 5-33 - - 9.5 XN (Cross Section North) 9.0 1-33 - - 10.8 B (Bosun Bank) 14.9 3.1 7.4 29.90 15.3 Cc (Cowichan Bay) 61.0 12.0 8.1 29.99 95.4 W (Satellite Channel West) 68.9 10.9 8.1 29.77 82.2 E (Satellite Channel East) 50.5 5.9 7.9 30.03 25.7 ‘ benthos sampled with a 0.2 m? Van Veen grab (all other stations sampled with 0.1 m? grab) Vol. 12; No. 2 THE VELIGER Page 213 Basin, near Victoria (DUNNILL & Extis, 1969) at 22m in a black silt (78.9% silt-clay), hence is tolerant of a considerable range of sediment grain sizes. Probably most of the stations sampled off Moresby Island and in Satellite Channel were below the bathymetric range of M. yoldi- formis in southern British Columbia. Both station 19, in the lee of Moresby Island, and Sooke Basin are in sheltered locations. The species also occurs in a protected situation in Nanoose Bay, Vancouver Island. Shelter from strong currents appears to be a pre- requisite for this small, fragile species to become estab- lished. Despite the wide variation in sediment types found in the survey areas (see section on Geology), few clear-cut differences were found in the distribution of the remaining 7 species, Macoma alaskana, M. brota, M. calcarea, M. carlottensis, M. elimata, M. incongrua, and M. lipara. Often many of these species occurred together (Figures 6 and 7) at the same station. All are sub-littoral, with bathymetric ranges in southern British Columbia extend- ing below the deepest station sampled. Ranges of these species are listed in Table 2 and bathymetric distribution trends shown in Table 3. Macoma alaskana Dat, 1900 was somewhat restricted in its distribution. Where it was found, “average sizes” of individuals tended to be greatest at the deeper stations, below about 50m, although the greatest density was at a shallow station (no. 19, 29m). Like Macoma carlottensis, M. alaskana was present at some stations and absent at others where depths and sediments were almost identical, indicating some other factor was limiting. It was not found at the more exposed stations adjacent to Swanson Channel (Figure 2) where currents might be too strong for small species such as M. alaskana to become established, nor was it found in the very fine-grained sediments in Cowichan Bay and Fulford Harbour (Figure 4). Macoma brota Dau, 1916 was widely distributed in the survey areas, with a trend for greatest biomasses and “average sizes” of individuals to be found at depths of more than 40 m. Densities, biomasses and “average sizes” were generally greater off Moresby Island and at Satellite Channel East than elsewhere in Satellite Channel. “Aver- age sizes” of M. brota on very fine-grained sediments were relatively low in comparison. with those off Moresby Island, yet would still seem too high for it to be said that these sediments were unfavourable to the species. Macoma calcarea (GMELIN, 1791) was present in collections from most stations off Moresby Island, but was not found elsewhere in Satellite Channel, although it is known to occur a few miles north of Cowichan Bay. Densities, biomasses, and “average sizes” all were markedly greater in water deeper than about 40 m. The apparent absence of Macoma calcarea in areas where sediments were very fine-grained, i.e., Fulford Harbour and Cowichan Bay, suggest grain size may be an important limiting factor for the species. Possibly the sheltered conditions in some of these localities, reflected by fine bottom sediments, or even the annual deposition of fine-grained material from winter run-off of the Cowi- chan River, may also be unfavourable. Macoma carlottensis WHITEAVES, 1880 was widely dis- tributed in the survey area and showed no obvious pref- erence for any particular depth zone or sediment grade. Densities and biomasses were roughly equally great at extremes of depth and sediment types surveyed, but “‘av- erage sizes” tended to be low on the coarse and fine sediment extremes. The species was found in equally high densities in sheltered environments in Fulford Harbour and Cowichan Bay and in more exposed conditions at Satellite Channel East and West. Macoma elimata DUNNILL & Coan, 1968, the most widely distributed Macoma in the survey area, was found in greatest densities at shallow stations (less than 40m), but biomasses and “average sizes” tended to be greatest in water deeper than 40 - 50 m. Very fine sediments, as in Cowichan Bay and at Satellite Channel West, appear unfavourable to the species. Bio- masses and “average sizes” there were low, even in water deeper than 50 m. However, the species was present in fine sediments in Fulford Harbour with relatively high density, biomass, and “average weight.” The species ap- parently has a tolerance for a fairly wide range of sediment types. Macoma incongrua (vON MarTENS, 1865) was the only Macoma regularly found on “shell-gravels,”’ at stations exposed to strong currents (2 - 3 knots) sweeping through Moresby Passage. However, the greatest “‘average sizes” of individuals of the species were found at stations away from the “shell-gravels” where current velocities were lower (1 - 2 knots). At the mouth of Moresby Passage (Figure 2), a reef with an average depth of about 36m (and exposed at one point as Canoe Rock) affords stations below this depth some protection from currents. Densities, biomasses, and “average sizes” of the species on the “shell-gravels” here increased as depth and degree of shelter increased. At all stations surveyed, densities, biomasses, and “aver- age sizes” of individuals tended to be greatest in water deeper than 40-50 m. Macoma incongrua was generally not found at stations where sediment contained more than about 50% silt-clay Page 214 THE VELIGER Vol. 12; No. 2 Table 2 Ranges in Distribution of Macoma off Moresby Island and in Satellite Channel Species Macoma alaskana Macoma brota Macoma calcarea Macoma carlottensis Macoma elimata Macoma incongrua Macoma lipara (m) Depth Range where found 14.2-65.0 14.2-85.0 29.0-85.0 9.0-80.0 9.0-85.0 9.0-85.0 29.0-85.0 [data from DuNNILL, 1968] and where it did occur in such sediments, densities, bio- masses, and “average sizes” were low. Macoma lipara Daut, 1916 was collected at every sta- tion off Moresby Island, but elsewhere was found only at Satellite Channel East. There was a trend for densities, E > — ase 2 gf ae ¢ gS Fe ° Ss Se) SI 14.0-36.0 18.1 11.2 15.3-95.4 52.2 449.0 14.0-45.5 225.0 873.0 9.5-95.4 344.0 13.6 9,5-95.4 157.0 117.0 9.5-82.2 89.2 182.1 14.0-45.5 17.0 392.0 Range of “Average Sizes” (g) 0.03- 1.2 0.03-12.0 0.7 - 7.4 0.01- 0.25 0.13- 3.0 0.02- 4.3 6.4-42.9 biomasses, and “average sizes” to be greatest at depths of more than 40 m. “Average sizes” were generally high, Table 3 even for this, the largest sub-littoral Macoma species in southern British Columbia and indicate a scarcity of young individuals. Possibly the species may have had poor Trends in Distribution of Macoma off Moresby Island and in Satellite Channel Species Macoma alaskana Macoma brota Macoma calcarea Macoma carlottensis Macoma elimata Macoma incongrua Macoma lipara Maximum Densities Generally shallower than 50 meters Generally deeper than 40 meters Generally deeper than 40 meters Roughly equal at shallow and deep stations Shallower than 50 meters Roughly equal at shallow and deep stations Generally deeper than 40 meters Maximum Biomasses Generally shallower than 50 meters Generally deeper than 40 meters Generally deeper than 40 meters Roughly equal at shallow and deep stations Roughly equal at shallow and deep stations Roughly equal at shallow and deep stations Generally deeper than 40 meters Maximum “Average Sizes” Deeper than 40 meters Deeper than 40 meters Deeper than 40 meters Roughly equal at shallow and deep stations Deeper than 40 meters At the deeper stations Deeper than 40 meters Vol. 12; No. 2 THE VELIGER Page 215 success in reproducing itself in the last few years at the north end of Moresby Island. The apparent absence of the species in sheltered loca- tions and on fine-grained sediments indicates these are unfavourable to Macoma lipara. Large adult specimens were regularly found near the surface of the sediments, suggesting the species is a shallow burrower. However, PamatmMat (1961) found distribution of M. secta, another large (intertidal) species independent of size, and this may also be true of M. lipara. }-—_——————___ Moresby Island fe 20 10 S Macoma alaskana 0 iS] 100 50 Macoma brota 0 oy = = 250 125 Macoma calcarea cm 0 Sao = E 400 oO a. Z 200 5 ~ Macoma carlottensis = 0 = = 200 A 100 Ng NN Macoma elimata oF S N iI 100 50 Macoma incongrua Macoma lipara Silty-sands We ZZ DISCUSSION In shell morphology, Macoma brota, M. calcarea, M. elimata, and M. lipara are very similar and their similar- ity is apparently reflected in their environmental require- ments. They are frequently found together off Moresby Island (Figures 6 and 7). Examination of Figure 8 shows these species all tend to have maximum biomasses and “average sizes” in water deeper than about 40 m and in sediments with a silt-clay content between roughly 15 and a Satellite Channel — Shell 4 gravels ao ttn, ~ SS x NS SS SN ~ AS AS AS RS S SS N WLLLLLB 7/,] WITT. 1/112 So 8 soa Sa N XN na tae Gag = N S N NS - NS IS FS ~ SBS AS SN 8 N SS NOSES I RS S NN 8 N A S NS 8 S § a= S&S = SS & oo = =— = =~ SN WN S : SS S S § __sNaé S S U1. W772 —_ W FCENE B XN XCXS 2 a a QO C Station Figure 6 Densities of populations of sub-littoral species of Macoma off Moresby Island and in Satellite Channel Page 216 THE VELIGER i Vol. 12; No. 2 50%. Macoma calcarea and M. lipara are apparently able situations, settle there but are then short-lived and more restricted in their distribution than M. brota and M. probably fail to survive to reproductive maturity, in which elimata and perhaps are less tolerant of the finer grained case they are dependent on replacement from outside sediments. populations in more favourable locations. The presence of Macoma brota and M. elimata on these The smaller species, Macoma alaskana and M. incon- very fine-grained sediments (containing more than 80% grua (Figure 9) also appear to favour water deeper than silt-clay) and the low “average size” of individuals, sug- 40-50m and sandy sediments. Macoma carlottensis is gest the young of these animals are carried into unfavour- exceptional and appears tolerant of shallower water and Moresby Island ————————+}— Satellite Channel —of |>—_——_———_ Silty- —— : ilty-sands |— er 10 < SN Macoma alaskana S N S 500 0 B = ay a —) 250 Macoma brota ~ 0 1000 P S --8s - ee oO i= © A 500 Macoma calcarea = = ~ © 2 20 0 = = = oo_ 2 SS S = ~_ o a ~“ = 10 3 K wo S S Ss . ~ N ~ Macoma carlottensis S S S N : g S § 2 NSS SN fa) 0 900 = = — SS A oso IN IS S Macoma elimata N S SNANaWAN A N S N NSNNNSASAAB N ~ N 200 0 SS SSSSSSNSSHSS8S -~-anNnrwtWNS SS 100 Macoma incongrua S 250 N N Macoma lipara S S 0 ne 122 2 47 9 G W FCENE B XNXCXS Station Figure 7 Biomasses of populations of sub-littoral species of Macoma off Moresby Island and in Satellite Channel Wola l2-.INo. 2 Macoma brota THE VELIGER Page 217 Macoma elimata 2 = 1 a 3 a=) EB a=) : LD AT SO ae 5 ® = 10 a) : Macoma lipara ty a 30 d Bal wet weight/m* (g) : © ei @ depth (m) 0-10 10-100 100-1000 ~ ® jo O° © & 5-50 9% 8 10 50- 75 ®@ ® e CO es 75-100 & a e 20 40. 60 80. 100 % Silt-Clay Figure 8 Plots of “average size” of Macoma brota, Macoma calcarea, Macoma elimata and Macoma lipara versus depth and % silt-clay in sediments a greater range of sediment types than the other species examined. The mean number of different species of Macoma oc- curring in hauls off the north end of Moresby Island on silty-sands was 5.3 compared to only 1.7 on “shell-gravel” (Figures 6 and 7). In the rest of Satellite Channel, the mean was 3.3. The paucity of Macoma species found on “shell-gravels” seems to result from the prevailing strong currents there which may prevent them from becoming established or may hinder their feeding. The siphons of species such as Modiolus modiolus (Linnagus, 1758) and Humilaria kennerleyi (Reeve, 1863), which flourish on the “shell-gravels,” are very short and have wide bores, in diametric contrast to those of Macoma, which are very long and of small bore. However, observations made on sub-littoral Macoma species in aquaria suggest some of these are not obligatory detrital feeders but can shorten their inhalant siphons and feed from the water above the bottom. This behaviour has also been reported for the Atlantic species, Macoma balthica (Linnazus, 1758) (BRAEFIELD & NEWELL, 1961). The mean wet weight/m’ of all macomas taken with the 0.1 m? Van Veen grab from 8 stations below 40 m off the north end of Moresby Island, was 1737 g (= 114g dry organic matter/m’, using the mean of the conversion fac- tors for Macoma listed in THorson (1957) ). It is evident that the area has an exceptionally rich infaunal standing crop. In comparison, Hote (1963) and Sanpers (1956) obtained total faunal mean dry organic matter weights of 11.2 and 54.627 g/m? for the English Channel and Long Island Sound, respectively. Food must be plentiful off Moresby Island to support this large standing crop and may not at present be a limiting factor governing the den- sities and biomasses of Macoma in this location. Page 218 THE VELIGER Vol. 12; No. 2 1.5 Macoma alaskana 0 20 40 60 80 100 0.3 Macoma carlottensis Mean Wet Weight per Individual (g) Macoma incongrua wet weight/m? (g) 0-10 10-100 100 - 1000 depth (m)0-5 5-10 10-15 0. & 2 © Bo 8 fF 50-75 ¢ ©@ 8 75-100 8 a ie % Silt-Clay Figure 9 Plots of “average size” of Macoma alaskana, Macoma carlottensis and Macoma incongrua versus depth and % silt-clay in sediments Frequently, 6 different species of Macoma were taken in a single anchor dredge haul at the north end of Moresby Island, from an estimated area of less than 0.7m’, and 5 different species were taken from areas of 0.1m? with the Van Veen grab (see DuNNILL, 1968). At station 19, the two anchor dredge hauls captured between them all 8 species of Macoma found sub-littorally in the survey (Figures 6 and 7). Macoma yoldiformis, collected at sta- tion 19, is not figured since the authors consider it a littoral species. According to Gause (1934), as a result of competition, two similar species scarcely ever occupy similar niches (by niche he means “. . . what place the given species oc- cupies in a community, i. e. what are its habits, food and mode of life.”), but displace each other so that each utilizes “certain peculiar kinds of food and modes of life in which it has an advantage over its competitor.” It seems probable that the merging and diverging of currents flowing through the channels at the north end of Moresby Island would generate extensive eddies. These might aid in dispersal of larvae of all local species over the submerged bank and could thus account for the dif- ferent species being brought together initially. There is some evidence (see above) that food may be more than adequate to support the existing Macoma populations off Moresby Island so that interspecific competition is lessened, thus permitting the coexistence of these closely related species. However, determination of the exact “niches” occupied by each of these coexisting species of Macoma off Moresby Island is beyond the scope of the present study. LITERATURE CITED AppicotT, WARREN OLIVER 1952. Ecological and natural history studies of the pelecypod genus Macoma in Elkhorn Slough, California. Master of Arts thesis, Stanford Univ., 89 pp. BERNARD, FRANK a 1967. | Prodrome for a distributional check-list and bibliogra- phy of the marine Mollusca of the west coast of Canada. Fish. Res. Brd. Canada, Tech. Rept. No. 2: 261 pp. Bouyoucos, GrorcE JOHN 1951. A recalibration of the hydrometer method for making mechanical analyses of soils. Agron. Journ. 43: 434 - 438 BRAEFIELD, A. E. « G. E. NEWELL 1961. The behavior of Macoma balthica (L.) Biol. Assoc. U. K. 41: 81 - 87 Journ. Mar. Vol. 12; No. 2 THE VELIGER Page 219 DuNNILL, Ropert M. 1968. A taxonomie and ecological investigation of the genus Macoma (Pelecypoda) in southern British Columbia. Master of Sci. thesis, Univ. Victoria, 155 pp. DuNNILL, Rospert M. & EUGENE Victor CoAN 1968. A new species of the genus Macoma (Pelecypoda) from west American coastal waters, with comments on Macoma cal- carea (GMELIN) 1791. National Mus. Canada, Nat. Hist. Paper 43: 19 pp. DunnILL, Rosert M. & Derek V. ELLIS 1969. Recent species of the genus Macoma (Pelecypoda) in British Columbia. National Mus. Canada, Nat. Hist. Pap. 45: 34 pp. Exuis, DEREK V. 1967. Quantitative benthic investigations. IT. Satellite Channel species data, February 1965 - May 1967. Fish. Res. Brd. Canada, Tech. Reprt. No. 35: 8 pp.; 169 tables; 2 figs. in press Quantitative benthic investigations. III. Locality and environmental data for selected stations (mainly from Satellite Channel, Straits of Georgia and adjacent inlets). Fish. Res. Brd. Canada, Tech. Rprt. Gause. G. F 1934. The struggle for existence. (Repr. 1964) Hafner, New York, 163 pp. HER.LINVEAUxX, Ricuarp H. 1962. | Oceanography of Saanich Inlet in Vancouver Island, British Columbia. Journ. Fish. Res. Brd. Canada 19 (1) : 1-37 HER.LINVEAUx, RicHarp H., O. D. Kennepy «& H. J. HoLiisTEr 1960. (MS) Oceanographic data record. Coastal Seaways project, November 16-December 11, 1959. Fish. Res. Brd. Canada, MS Reprt. Oceanogr. & Limnol. Ser. No. 58: 134 pp. Hotme, Norman A. 1953. The biomass of the bottom fauna in the English Channel off Plymouth. Journ. Mar. Biol. Assoc. U. K. 32: 1 - 49 1964. | Methods of sampling the benthos. Adv. Mar. Biol. 2: 171 - 260 Jones, Norman S. 1950. Marine bottom communities. Biol. Rev. 25: 283-313 MacGinitTi£, GEorGE EBER 1935. Ecological aspects of a California marine estuary. Amer. Midl. Natur., 16 (5) : 629 - 765 PaciFic OcEANOGRAPHIC Group 1959a. (MS) Physical and chemical data record. Coastal Sea- ways project, March 3lst-April 22nd, 1959. Fish. Res. Brd. Canada. MS Rprt. Oceanogr. Limnol. Ser. No. 47: [only p. 11 seen] 1959b. (MS) Physical and chemical data record. Coastal Sea- ways project, June 8-July 1, 1959. Fish. Res. Brd. Canada. MS Rprt. Oceanogr. Limnol. Ser. No. 52: 210 pp. PAMATMAT, Mario M. 1961. A study of various aspects of feeding and related prob- lems in Macoma secta and Neoamphitrite robusta. | Unpubl. MS Univ. Washington, 31 pp. SANDERS, Howarp L. 1956. | Oceanography of Long Island Sound, 1952-1954. X. Biology of marine bottom communities. Bull. Bingham Oceanogr. Coll. 15: 345 - 414 SHELForD, Victor E. « E. T. TowLer 1925. Animal communities of the San Juan Channel and adjacent areas. Univ. Wash. Publ., Puget Sound Biol. Sta. 5: 31-73 SHELForD, Victor E., A. O. WeesE, L. A. Rice, D. I. RasMUSSEN & A. MacLean 1935. Some marine biotic communities of the Pacific coast of North America. Part I. General survey of the communities -- their extent and dynamics. Ecol. Monogr. 5 (3) : 249 - 332 Tuorson, GUNNAR 1957. Bottom communities. Jn Treatise on marine ecology and paleoecology. J. W. Hedgpeth (ed.) Geol. Soc. Amer. Mem. 67, 1: 461 - 534 Tutty, J. P « A. J. Dopimeap 1957. Properties of the water in the Strait of Georgia, British Columbia, and influencing factors. Journ. Fish. Res. Brd. Canada 14 (3): 241-319 Wa.picHuck, M. 1957. Physical oceanography of the Strait of Georgia, British Columbia. Journ. Fish. Res. Brd. Canada 14 (3) :321 - 486 Wans, Frank Fenc-Hut 1955. Recent sediments in Puget Sound and portions of Wash- ington Sound and Lake Washington. Ph. D. thesis, Univ. Wash., 160 pp. WENNEKENS, Marce P. 1959. Marine-environment and macro-benthos of the waters of Puget Sound. San Juan Archipelago, southern Georgia Strait, and Strait of Juan de Fuca. Ph. D. thesis, Univ. Wash., 298 pp. Page 220 THE VELIGER Vol. 12; No. 2 Additional Bathymetric and Locality Data for some Opisthobranchs and an Octopus from Santa Barbara County, California RICHARD S. LEE Santa Barbara Museum of Natural History, Santa Barbara, California 93105 AND PATRICK BROPHY Pacific Bio-Marine, Venice, California go291 RECENTLY AN EXCELLENT annotated list of the opistho- branch mollusks from Santa Barbara County (SPHON & Lance, 1968) summarized all the geographic and bathy- metric information available on the local members of this group up to the date of publication. Since that time the junior author of this report has uncovered additional information, including new bathymetric records and the presence of 8 unlisted species in the waters off Santa Barbara County. LIST or SPECIES Acanthodoris atrogriseata O’DonocHUE, 1927 Intertidal at Serena Cove, Carpinteria. First record for Santa Barbara County. Acanthodoris hudsont MacFartanp, 1905 Trawled at 700 (?) feet at Gaviota. Found in a sunken holdfast. First record for Santa Barbara County. Acanthodoris nanaimoensis O’DoNoGHUE, 1921 Intertidal, Purisima Point. Not previously recorded from Santa Barbara County, although collected at Shell Beach, San Luis Obispo County (RoLLer « Lone, 1969). Anisodoris nobilis (MacFarLanp, 1905) Intertidal to 840 feet off Santa Cruz Island. Archidoris montereyensis Coorer, 1863 Intertidal to 840 feet off Santa Cruz Island. Berthellina engeli GARDNER, 1936 25 feet, Santa Cruz Island. Previously recorded only as far north as San Diego. Cadlina flavomaculata MacFarianp, 1905 Intertidal to 723 feet off Port Hueneme (Ventura County). Dendrodoris sp. Undescribed white and brown species. 30 feet, off Naples, Santa Barbara County. Dendronotus tris Cooper, 1862 15 to 702 feet, off Gaviota. Doto wara Marcus, 1961 Santa Barbara Yacht Harbor. First record for Santa Barbara County. Gastropteron pacificum Brercu, 1894 Intertidal to 804 feet. The first recorded specimen from the County was taken from the backwash of the filtration unit of the Santa Barbara Undersea Gar- dens, while the remaining records are based on speci- mens trawled at depths of 510 to 840 feet from Rincon Point and Gaviota (BerTscH, 1969). Hermaeina oliviae MAcFaRLAND, 1966 Holdfast, Santa Barbara Channel. Depth unknown. First record for Santa Barbara County. Petelodoris spongicola MAcFaRLAND, 1966 One specimen taken in 690 feet in a sunken kelp holdfast off Gaviota. Not previously recorded from Santa Barbara County. Phidiana pugnax Lance, 1962 Intertidal to 702 feet, off Gaviota, found in a sunken kelp holdfast. Philine bakeri Dau, 1919 510 to 572 feet, off Gaviota. Phyllaplysia taylori Dai, 1900 15 feet, Santa Cruz Island. Not previously recorded from Santa Barbara County. Pleurobranchaea californica MacFaRLAND, 1966 Subtidal to 714 feet, off Gaviota. Vol. 12; No. 2 In October and November of 1968, 3 female Opistho- teuthis californiana Berry, 1949 were trawled from off the Santa Barbara coast. The first was taken on October 24, 1968, at approximately 840 feet, off Gaviota; the second, gravid, was taken at the same depth off Santa Barbara Harbor. Both of these specimens were collected by the junior author. The third specimen was taken at a similar depth by Mr. Harold Durrah, a commercial fisherman, who kindly brought it to our attention. Berry (1949) originally described the species on the basis of 2 females taken off Eureka, Humboldt County, California, and then later (1955) described a male from the same area. A substantial range extension southwards to Monterey was noted by Puitups (1961). On the basis of these notes, we feel that the Santa Barbara speci- mens represent the southernmost records for this unusual webbed octopus. However, it is suspected that as commer- cial fishermen continue their deep water exploration of this coast, farther southern records will be established. ACKNOWLEDGMENTS We wish to thank Mrs. Thomas Rogers of the Santa Barbara Museum of Natural History for her aid in the identification of the opisthobranchs; Mr. Allyn G. Smith THE VELIGER Page 221 of the California Academy of Sciences for his encourage- ment and suggestions on this note; Mr. Harold Durrah, Mr. Shane Anderson, Mr. Samuel Spaulding of Santa Barbara for supplying specimens and data. LITERATURE CITED Berry, SAMUEL STILLMAN 1949. = — & =e (a) qc =) QA 1.45 ! 43 3.38 1.91 oD |e 0.63 3.05 2.14+0.082 0.475 0.0071 0.69+0.032 3.11+0.042 (1.71-2.43) | (0.442-0.496) (0.51-0.79) | (2.95-3.35) 1.92+0.105 0.519+0.0110 a 0.58 +0.058 3.33 +0.160 (1.68-2.19) (0.496-0.549) = 3 0.51-0.76 2.90-3.59) 3.96 + 0.058 0.92+0.040 | 4.31+0.130 3.82-4.08) | (0.546-0.568 (0.86-1.02) | _(4.21-4.57) 3.63 + 0.056 0.89+0.021 | 4.08+0.096 3,39-3.85 0.500-0.578 35 3.79-4.56 6.43+0.112 | 0.462+0.0069 Agu 187+0.051 | 3.450.059 (6.14-6.93) | (0.439-0.489) (44-44) (1.63-2.03) | (3.31-3.76) Page 246 THE VELIGER Vol. 12; No. 3 fied it in that genus despite the very small size, which corresponds more with the Bismarck-Solomon species. Pilsbrycharopa timorensis (B. Renscu, 1935) Charopa brunnescens timorensis B. Renscu, 1935, Sitz.-Ber. Ges. naturf. Freunde, Berlin, 1934: 323, fig. 7 — West Timor; Sotem, 1958, Arch f. Mol- lusk. 87 (1-3): 25. Description: Shell larger than average, with slightly less than 4 normally coiled whorls. Apex and spire slightly and evenly elevated, body whorl descending a little more rapidly, H/D ratio 0.541. Apical whorls 14, early sculp- ture eroded, last one-third whorl with very low radial ribs. In umbilicus a faint trace of spiral cording visible on first nuclear whorl. Remaining whorls with irregular, low, protractive radial ribs whose interstices are less than twice their width. Microsculpture almost totally eroded, occa- sionally traces of fine microradials and even finer micro- spirals visible, 3 to 4 microradials between each pair of major ribs. No trace of secondary spiral cording. Sutures moderately impressed, whorls flattened laterally above evenly rounded periphery and on basal margin.’ Umbili- cus widely open, cup-shaped, contained 2.16 times in the diameter, margins rounded. All color leached from shell. Aperture ovate, flattened basally and laterally above peri- phery, inclined about 30° from shell axis. Height of holo- type 2.01 mm, diameter 3.7 mm. Holotype: Timor: Nenas at 1000 m to 2000 m elevation. Zoologisches Museum der Humboldt Universitat, Berlin. Remarks: Unfortunately the holotype and only known specimen was damaged in an attempt at cleaning heavy incrustations. The shell is very worn and obviously collec- ted dead. It differs from the type lot of Pilsbrycharopa brunnescens in having a much wider umbilicus and in lacking secondary spiral cording, although unquestionably it is closely related. The difference in umbilical size is large enough to warrant specific separation following the pattern in similar situations found among Pacific Island species. Pilsbrycharopa brunnescens (MOLLENDoRFF, 1892) Patula (Discus) brunnescens MOLLENDORFF, 1892, Nachr.-Bl. dtsch. malak. Ges. 24: 87 — Tenimber Islands; Sotem, 1958, Arch. f. Mollusk. 87 (1-3): 2a, Diagnosis: Shell relatively large, diameter 3.82 - 4.08 mm (mean 3.95 mm), with 44 to 44 normally coiled whorls. Apex barely emergent or slightly elevated, lower whorls descending slightly, body whorl more rapidly, H/D ratio 0.546-0.568 (mean 0.559). Apical whorls 13 to 14, sculp- ture on early portion of narrow, somewhat wavy spiral ribs, 15 or 16 in number, with faint radial ribs and a development of strong, broadly rounded radial ribs on the last quarter to half whorl. Postnuclear whorls with promi- nent, lamellar, protractively sinuated radial ribs, 82-98 (mean 89.2) on the body whorl, whose interstices are 2 to 4 times their width. Ribs/mm 6.77-7.77 (mean 7.19). Microsculpture of fine, regularly spaced radial riblets, crossed by much finer, more crowded spiral riblets with a secondary sculpture of moderately prominent spiral cords whose interstices are about 3 to 4 times their width. Sutures deep, whorls strongly rounded above, somewhat flattened laterally above periphery and on basal margin. Umbilicus relatively narrow, “V-shaped, regularly de- coiling, contained 4.00-4.57 times (mean 4.31) in the dia- meter, margins rounded. Color light reddish yellow horn without darker flammulations. Aperture sub-circular, slightly flattened laterally above periphery, on basal, and on columellar margin, inclined about 25° from the shell axis. Pilsbrycharopa brunnescens is much smaller and has much less prominent radial elements in the apical sculp- ture than does P nigrofusca; P. kobelti is much smaller and has a wider umbilicus; PR timorensis is much more widely umbilicated.. Description: Shell large, with slightly more than 44 nor- mally coiled whorls. Apex and spire slightly and evenly el- evated, body whorl descending more rapidly, H/D ratio 0.556. Apical whorls 13, sculpture mainly eroded with prominent, broadly rounded radial ribs crossed by finer, more widely spaced spiral ribs visible on the last third. Post- nuclear whorls with prominent, lamellar, narrow, protrac- tively sinuated radial ribs, 86 on the body whorl, whose interstices are 2 to 4 times their width. Microsculpture mostly eroded, where visible consisting of regularly spaced radial riblets crossed by much finer and more crowded spiral riblets with a secondary sculpture of moderately prominent, fairly widely spaced spiral cords. Sutures deep, whorls strongly rounded above, slightly flattened laterally above periphery and on basal margin. Umbilicus rela- tively narrow, “V”-shaped, regularly decoiling, contained 4.00 times in the diameter. Color light reddish yellow horn. Aperture sub-circular, inclined about 25° from the shell axis. Height of lectotype 2.27 mm, diameter 4.08 mm. Lectotype: Tenimber Islands. Natur-Museum Sencken- berg, Frankfurt number 165692. Range: Tenimber Islands and New Guinea. Material: Tenimber Islands (4 specimens, SMF 165692- Vol. 12; No. 3 4). Papua:- Vikaiku, Angabunga River, inland of Hall Sound (30 specimens, MHNG, FMNH 159264). Remarks: The type set from Timor Laut and the shells from Vikaiku agree very well in shape, color and major sculptural features. Both average between 15 and 16 spiral apical cords and their rib counts are essentially identical. The slightly smaller size and lower whorl count of the Vikaiku shells may reflect either bias for large size in the type set remnant studied or, more probably, fewer gerontic individuals in the former set. A possibly signifi- cant difference is the complete absence of secondary spiral cording in the Vikaiku shells, while it is very prom- inent in the Tenimber sample. I consider the available evidence too fragmentary to warrant separation, but on the basis of variation patterns seen in other taxa I suspect that the two are distinct. Pilsbrycharopa brunnescens is intermediate between P kobelti and P. nigrofusca in size and sculpture, but differs from both in its narrower umbilicus and higher spire. The radial apical sculpture is almost exactly intermediate in character. Pilsbrycharopa nigrofusca (E. A. Situ, 1896) Charopa nigrofusca E. A. Smiru, 1896, Journ. of Ma- lac. 5 (2): 18; plt. 2. figs. 10-12 — German New Guinea. Pilsbrycharopa papuana SotEeM, 1958, Arch. f. Mol- lusk. 87 (1-3): 24-25; plt. 3, figs. 2-6 —Kon- stantinhafen, New Guinea. Pilsbrycharopa nigrofusca (E.A.SmrrH), SoLem, 1958, Arch. f. Mollusk. 87 (1-3): 25. Diagnosis: Shell very large, diameter 6.14 - 6.93 mm (mean 6.43 mm), with 44 to 44 relatively loosely coiled whorls. Apex barely emergent, spire flat, body whorl des- cending slightly, spire protrusion about one tenth body whorl width, H/D ratio 0.439 - 0.489 (mean 0.462). Api- cal whorls 1%, sculpture of fine, relatively crowded spiral ribs, crossing lower, quite broadly rounded, somewhat re- tractive radial ribs which are covered with very fine, closely spaced radial riblets occasionally visible on a well- preserved specimen. Postnuclear whorls with prominent, “V-shaped, strongly protractively sinuated radial ribs, 114-132 (mean 124.3) on the body whorl, whose inter- stices are 2 to 5 times their width. Microsculpture a lattice of coequal radial and spiral riblets, equally spaced, 7 to 15 microradials between each pair of major ribs. Sutures moderately impressed, whorls strongly rounded above, greatly flattened laterally above periphery and slightly below with rounded periphery and basal margin. Umbili- cus broadly “V”-shaped, regularly decoiling, contained THE VELIGER Page 247 3.31 - 3.76 times (mean 3.45) in the diameter. Color reddish yellow brown without darker maculations, apex lighter in tone. Aperture sub-circular, strongly flattened above periphery with slightly deflected lip and slightly flattened lower lateral margin and umbilical edge, inclined almost 25° from the shell axis. The flat spire, large size, wide umbilicus, loosely coiled whorls and microreticulated sculpture immediately sepa- rate Pilsbrycharopa nigrofusca from the other species of Pilsbrycharopa. Species of similar size, P. gressitti and P schneideri, have very small umbilici and reduced radial sculpture. Description: (nigrofusca) Shell very large, with slightly more than 44 relatively loosely coiled whorls. Apex and spire flat, last whorl descending slightly, H/D ratio 0.457. Apical whorls 13, sculpture of about 20 fine spiral ribs, crossing much lower, broadly rounded radial ribs with a fine secondary sculpture of radial riblets visible on lower portion. Postnuclear whorls with low but prominent, “U”- shaped, strongly protractively sinuated radial ribs, 114 on the body whorl, whose interstices are 2 to 5 times their width. Microsculpture a lattice of co-equal radial and spiral riblets. Sutures deep, whorls sharply rounded above, greatly flattened laterally above periphery and slightly flattened below. Color reddish yellow brown without darker maculations, apex lighter in color. Umbilicus broad- ly “V-shaped, regularly decoiling, contained 3.36 times in the diameter. Aperture subcircular, strongly flattened laterally above periphery, slightly flattened laterally be- low periphery and on columellar margin, inclined about 25° from the shell axis. Height of lectotype 2.81 mm, diameter 6.15 mm. (papuana) Shell very large, with 43 relatively loosely coiled whorls. Apex and spire flat, body whorl moderately descending, H/D ratio 0.443. Apical whorls 14, sculpture of fine spiral ribs, about 23 in number, reticulated by slightly finer radial ribs on the early portion with an intrusion of broadly rounded radial ribs on the last one- third whorl. Postnuclear whorls with rounded, prominent, protractively sinuated radial ribs, 116 on the body whorl, whose interstices are 2 to 3 times their width. Microsculp- ture a lattice of co-equal radial and spiral riblets in a somewhat waved pattern. Sutures deeply impressed, whorls evenly rounded at shoulder, strongly flattened lat- erally above periphery and on basal margin, with evenly rounded periphery. Color dark reddish yellow horn, apex somewhat lighter in tone. Umbilicus widely opened, “V”- shaped, regularly decoiling, contained 3.42 times in the diameter. Aperture large, ovate, flattened laterally above periphery and slightly on basal margin, inclined about 25° from the shell axis. Height of holotype 3.08 mm, diameter 6.93 mm. Page 248 Holotype of papuana: New Guinea: Constantinhaven. Natur-Museum Senckenberg, Frankfurt number 158151/1 ex-Mollendorff. Lectotype of nigrofusca: New Guinea: Konstantinhaven. British Museum (Natural History) number 96.6.1.21. Range: Known only from Konstantinhaven, New Guinea. Paratypes: B. M. (N.H.) 96.6.1.22 (nigrofusca) ; SMF 158182/3, FMNH 63527, UMMZ 141799 (papuana). Remarks: Inspection of the types of Charopa nigrofusca SmiTH, 1896, showed that Pilsbrycharopa papuana SOLEM, 1958, is a synonym, probably based upon material from the type lot of the former. The original figures of C. nigro- fusca are incorrect in proportions and led to the erroneous assumption that the two taxa were separable. The large size and flattened form of Pilsbrycharopa nigrofusca are the obvious features separating it from P brunnescens. This enlargement was not achieved by ad- ding whorls, but simply through overall increase. Rib spacing is slightly wider, but only to the extent propor- tional to size change. In having a slightly lower spire and proportionately wider umbilicus, P nigrofusca shows a characteristic linked change. In this instance, it is caused by depressing the plane of coiling and flattening of the whorls. Pilsbrycharopa brunnescens from Vikaiku has the spire protrusion/body whorl width index average 0.098, while in P nigrofusca it is 0.105 (see Table 2). The spire of P. brunnescens appears much higher, but the measured protrusion is only slightly less. Body whorl width averages 1.18 mm in P. brunnescens and is 1.88 mm in P. nigrofusca. There is thus an increase of 77% in mean diameter be- tween the species (3.63 in Vikaiku PR brunnescens to 6.43 in RP nigrofusca) but only a 59% increase in body whorl width. This is caused by more marked compression of the whorls in P. nigrofusca. Much more significance can be attached to the greater radial element in the apical sculpture of Pilsbrycharopa nigro fusca. Pilsbrycharopa densecostulata (THIELE, 1928) Charopa densecostulata TutELE, 1928, Zool. Jahrb., Syst. 55: 127; plt. 5, fig. 14 -—29km unterhalb Maeanderberg (Upper Sepik River), New Guinea. Pilsbrycharopa densecostulata (TuHrte), SoLe, 1958, Arch. f. Mollusk. 87 (1-3): 25. Remarks: I have not seen the single known example of this species, but the original description and figures leave no doubt as to its affinities. The apical sculpture, shape, umbilical form and radial sculpture all appear to be inter- THE VELIGER Vol. 12; No. 3 mediate between the features of species such as Pilsbry- charopa brunnescens and the very specialized PR renschi or P. schneideri. Maeanderberg is a classic collecting area on the Upper Sepik River, Sepik District, New Guinea located past the great bend of the Sepik quite near the border of West Irian at about 4°10’ S, 141°25’ E. Pilsbrycharopa gressitti SOLEM, spec. nov. (Figures 1d to 1f; 2f to 21) Diagnosis: Shell very large, diameter 6.27 mm - 7.32 mm (mean 6.76 mm), with 3 to 44 normally coiled whorls. Apex and spire slightly to moderately and evenly elevated, spire protrusion averaging one-ninth body whorl width, last whorl descending more rapidly, H/D ratio 0.559-0.642 (mean 0.585). Apical whorls slightly more than 14, sculpture of about 15 - 18 fine and widely spaced spiral cords crossing much higher and more widely spaced radial ribs that become more crowded near end of apex. Post- nuclear whorls with narrow, low rounded radial ribs, in fresh material with fine periostracal extensions, that be- come extremely crowded and indistinct by middle of body whorl. Microsculpture occasionally distinguishable as very fine and crowded radial riblets, much finer and more crowded spiral riblets, with a secondary sculpture of low, very broad spiral cords whose interstices are usually less than twice their width. Sutures moderately impressed, whorls strongly rounded above, compressed laterally above periphery and on basal margin, with evenly rounded peri- phery and columellar margins. Umbilicus very narrow, “V-shaped, slightly decoiling, partly covered in adults by rolled reflection of columellar lip, contained 9.27 - 12.47 times (mean 10.74) in the diameter. Aperture ovate, compressed laterally above periphery and on basal margin, inclined about 25° from shell axis. Pilsbrycharopa gressitti has only a slightly elevated spire, a narrow umbilicus, and is quite large. Species of similar size differ in having a minute or closed umbilicus and grossly elevated spire (P. schneideri) or a wide umbili- cus and regular ribbing (P nigrofusca). None of the other Pilsbrycharopa exceed 4mm in mean diameter. Description: Shell very large, with 3$ normally coiled whorls. Apex and spire very slightly and evenly elevated, last whorl descending much more rapidly, H/D ratio 0.563. Apical whorls more than 14, early portion wom, lower part with 16 narrow spiral cords, whose interstices are 5 to 6 times their width, with much higher, narrow, rounded, widely spaced radial ribs, whose interstices at first are 4 to 5 times their width, becoming more crowded near Vol. 12; No. 3 THE VELIGER Page 249 ES AALLLEL Biri abc -—— Figure 1 a-c: Holotype of Paryphantopsis dauloensis SoLEM, spec. nov. d-f: Holotype of Pilsbrycharopa gressitti SOLEM, spec. nov. Daulo Pass, Eastern Highlands, New Guinea, Bernice P Bishop Daulo Pass, Eastern Highlands, New Guinea, Bernice P. Bishop Museum Museum. Scale lines equal 1 mm Page 250 THE VELIGER ; Vol. 12; No. 3 Page a ——————————————a Figure 2 a-e: Paryphantopsis dauloensis SoLEM, spec. nov. Type lot. f-i: Pilsbrycharopa gressitti SoLEM, spec. nov. Type lot. Daulo Pass, Eastern Highlands, New Guinea. a - pallial region; Daulo Pass, Eastern Highlands, New Guinea. f - pallial region; b-genitalia; | c-d-detail of epiphallic diverticulum in two spe- g-h- terminal genitalia; i- interior of. penis cimens;_ e - interior of penis Scale lines equal 1 mm Dissections deposited in Bernice P. Bishop Museum Vol. 12; No. 3 end of apex. Postnuclear sculpture of low, rounded, radial ribs with slight periostracal extensions, becoming very crowded lower on spire, indistinguishable on body whorl. Microsculpture as in diagnosis. Sutures impressed, whorls strongly rounded above, compressed laterally above peri- phery and on basal margin, with evenly rounded peri- phery. Umbilicus very narrow, “V-shaped, slightly de- coiling, contained 12.44 times in the diameter, partly narrowed at aperture by columellar lip reflection. Aper- ture ovate, compressed laterally above periphery and slightly on basal margin, inclined about 30° from shell axis. Height of holotype 4.12 mm, diameter 7.32 mm. Holotype: New Guinea: Daulo Pass (ca. 6°03’S, 145°10’ W), Eastern Highlands, at about 8200 feet elevation. Collected on June 14, 1955 by J. Linsley Gressitt. Bernice P. Bishop Museum. Material: Daulo Pass (7 specimens, BPBM). Remarks: The very characteristic apical sculpture is per- fectly captured in Figure 1 d. In contrast to that of Pils- brycharopa nigrofusca (see SoLeM, 1958, plt. 3, fig. 2) the radial elements of the apical sculpture are narrow and distinctly higher than the spiral cords. Pilsbrycharopa schneider: has slightly greater accentuation of the radial elements. Great pleasure is taken in naming this species after its collector, J. Linsley Gressitt, whose work on the Pacific Island fauna has stimulated such interest in the Pacific biota. Description of soft parts: Foot broad, truncated anterior- ly, tail slightly tapering, bluntly rounded behind. Sole transversely corrugated in preservative, without longitu- dinal zonation. Pedal grooves deeply impressed, high on side of foot, suprapedal smaller than pedal, uniting above tail, no caudal horn or middorsal groove present. Slime network irregularly rectangular, units much smaller than lateral divisions below pedal grooves. Head and ommato- phores without marked peculiarities. Gonopore position not observed because of extreme retraction in available material. Body color light on sole and back of tail, an iridescent grey on sides of foot and neck, sole yellow-white. Mantle collar (MC) wide and thick, no glandular ex- tension onto mantle roof. Anus (A) opening just inside pneumostome, distinctly anterior of external ureteric pore (KX). Pallial region (Figure 2 f) measures 6.25 mm from edge of mantle collar to posterior end of kidney, distance from anterior edge of kidney to mantle collar about 2.6 mm. Lung roof clear of granulation. Kidney (K) bilobed, about 3.4mm long, slanting downward from _parietal- palatal margin after anterior third of rectal lobe, tapering posteriorly under intestinal loops. Ureter (KD) typical, THE VELIGER Page 251 narrow strip of lung roof visible between arms of ureter which are narrow at point of reflection. Heart (H) large, two thirds length of kidney. Principal pulmonary vein (HV) very inconspicuous, without major branching vis- ible. Hindgut (HG) departing from kidney about 3.65 mm behind edge of mantle collar. Apical genitalia not seen. Prostate (DG) of numerous slender acini opening into groove on inner surface of upper uterine chamber. Uterus (UT) bipartite, upper chamber very slender and thin walled, lower chamber swollen, biscuit-shaped, with thick glandular walls. Vas deferens (Figure 2, g-h) very large and glandular at first, narrowing to a slender tube before penioviducal angle, reflexing up to enter bulbous epiphallic head. Epiphallus (E) with swollen head nar- rowing after an anterior diverticulum (EL) followed by a slender tube with longitudinal pilasters leading to penis head. Penial retractor (PR) arising on diaphragm, rather long, inserting longitudinally on coiled shaft of epiphallus below epiphallic diverticulum. Penis (P) about 2mm long, elongately ovate, tapering from bulbous head down to slender atrium. Internally (Figure 21) with short lon- gitudinal pilasters clustering around epiphallic pore, main portion with modified stimulatory pad and accessory pil- asters, walls very dense and muscular. Atrium (Y) very short and slender. Free oviduct (UV) short, a narrow tube opening into very short vagina lateral to spermathe- cal insertion, without clearly defined internal structures other than longitudinal grooves. Spermatheca (S) with ovoid head lying just above prostate-uterus, slender shaft lightly bound to surface of prostate, approximately doub- ling in size just before inserting on penioviducal angle. Vagina (V) a short thick-walled, wide tube with heavy muscular walls. Free muscle system not studied, except to note typical passage of right ommatophoral retractor through penioviducal angle. Jaw fragmented in mounting, separate plates, about 3 times as long as wide on outer portions, central area fused. Radula with central about lu narrower than 1* lateral, mesocone extending slightly be- yond tip of basal plate. Laterals 12-13, 1* with basal plate about 13m wide and 16 long, mesocone extending up 6u beyond edge of basal plate. Ectocone and endocone equal in size on 1“ lateral, endocone increasing more rapidly than ectocone on outer laterals, basal plate be- coming shorter and wider. Shift to marginals in one or two teeth by sharp reduction in mesoconal length, less dram- atic size increase in ectocone and endocone, shift in basal plate from almost square to shorter than wide. Marginals 9 to 10, outer with basal plate width twice length, cusps becoming shorter, ectocone split by 8" marginal marginals often only with mesoconal remnant. (Based on 3 fragmentary specimens from the type set. They had been extracted previously with the apical parts remaining in the shells.) Page 252 Pilsbrycharopa renschi (Franc, 1952) Charopa vicina B.RENscH, 1930 (not PRESTON 1907), Zool. Anz. 89 (3-4): 87 — Batoe Doelang, Sumbawa and Rana Mésé, Flores, Lesser Sunda Islands; B. RenscuH, 1932, Zool. Jahrb., Syst. 63: 102; plt. 3, fig. 34; Sorem, 1958, Arch. f Mollusk., 87 (1-3): 25. Charopa renschi Franc, 1952, Bull. Soc. France 77 (1): 78 — New name for Charopa vicina RenscuH, 1930 not Preston, 1907. Description: Shell larger than average, with slightly more than 54 tightly coiled whorls. Apex and spire markedly and evenly elevated, spire protrusion about two fifths body whorl width, last whorl descending very slightly, H/D ratio 0.750. Entire shell encrusted and sculpture partly destroyed by fungal attack. Apex with both radial and spiral sculpture, details not detectable. Postnuclear whorls with fine, very crowded, vertical radial ribs, about 230 on the body whorl, that become retractive near umbil- ical closure. Microsculpture a lattice of radial and spiral el- ements, the latter weaker. All sculpture fainter below peri- phery of body whorl. Sutures not very deep, whorls strongly and evenly rounded above, becoming flatly rounded on outer margin. Umbilicus completely closed by reflection of lip. Color yellow horn with faint reddish tinge. Aperture crescentic, slightly more strongly rounded above and on umbilical margin. Columellar lip thickened and reflected. Height of holotype 2.86mm, diameter 3.82 mm. Holotype: Sumbawa, Batoe Doelang, west part of island, at 1000 to 2000 m elevation. Zoologisches Museum der Humboldt Universitat, Berlin. Paratype: Flores, Rana Mésé at 1 200 - 1 300 m elevation (SMF 5733). Additional Material: Sumbawa, Tamboka at 3000 feet elevation (BMNH 98.10.25.184). Remarks: The juvenile paratype is badly broken, has the apical whorls missing, and a narrowly open umbilicus. Although the juvenile (32 whorls) from Tamboka was somewhat worn, it showed that the apical sculpture con- sists of fine, very crowded spiral riblets with smaller, slightly lower radial riblets and an intrusion of low rounded radial ribs on the lower part of the apex. This serves to relate P renschi to Pilsbrycharopa despite the quite different shape. Differences from P baliana are given under that species. THE VELIGER Vol. 12; No. 3 Pilsbrycharopa baliana (B. RENscu, 1930) Charopa baliana B. ReNscH, 1930, Zool. Anz., 89 (3-4): 86; fig. 14 -— Gitgit and Batoeriti, Bali, Lesser Sunda Islands; B. ReENscu, 1932, Zool. Jahrb., Syst. 63: 102; Sorem, 1958, Arch. f. Mol- lusk., 87 (1-3): 25. Description: Shell larger than average, with 5} very tightly coiled whorls. Apex and spire markedly and evenly elevated, body whorl not descending more rapidly, spire protrusion a little less than two fifths body whorl width, H/D ratio 0.729. Apical and early postnuclear whorls with sculpture eroded. Lower whorls with thin, vertical, radial ribs, 151 on the body whorl, whose interstices are 3 to 5 times their width. Ribs become retractively sinuated upon basal umbilical area. Ribs/mm 12.39. Microsculp- ture a lattice of radial and spiral riblets, the latter dis- tinctly finer. Both macro- and microsculpture weaker be- low periphery of body whorl. Sutures deep, whorls strongly rounded above slightly angled periphery, compressed lat- erally, flatly rounded to basal margin, which is strongly rounded. Umbilicus a narrow crack, contained about 20 times in the diameter. Color reddish-yellow horn without flammulations. Aperture crescentic, strongly rounded on umbilical and upper palatal margins, parallel to shell axis. Columellar margin thickened. Height of holotype 2.83 mm, diameter 3.88 mm. Holotype: Bali, Gitgit at 500- 600m elevation. Zoolo- gisches Museum der Humboldt Universitat, Berlin. Paratype: Bali, Batoeriti at 800 m elevation (SMF 5734). Remarks: The paratype differed only in being slightly less elevated (H/D ratio 0.698) and a trifle smaller (dia- meter 3.82 mm). The whorl count was identical. Unfor- tunately, the apical sculpture was eroded. The very similar Pilsbrycharopa renschi (FRANG, 1952) differs in having a closed umbilicus when adult, finer and more crowded radial sculpture (ca. 230 ribs on the body whorl), a slightly less obtuse spire angle, and shallower sutures. Pilsbrycharopa schneideri (1. RENscu, 1937) Charopa schneideri 1. RENscH, 1937, Arch. f. Natur- gesch., N. FE, 6 (4): 587 - 588; figs. 29 - 31 (shell, genitalia, radula) — Malkong-Bach, Karlei, Ma- tong, Lomal, Patagun, Ulamona and Insel Lolo- bau, New Britain, Bismarck Archipelago. Vol. 12; No. 3 THE VELIGER Page 253 Table 3 Variation in Groups “B-E” Species of Pilsbrycharopa ° ° 6§3 | 4 2g eh E “ 3 e E Z E EB 8 3 & a 3 E ~ pane EY ae a Fe 5 Q P. densecostulata 0 = 23 3.75 0.613 32 0.67 5.60 (THIELE) P. gressitti SoLeM, GT RS 3.95+0.136 | 6.76+0.147 | 0.585+0.0131 44 0.60+0.030 | 10.74+0.518 spec. nov., Daulo Pass (3.53-4.44) | (6.27-7.32) | (0.559-0.642) | (33-44) (0.52-0.72) | (9.27-12.47) P. baliana (B. Renscw) | ALPS 2.75 3.85 0.714 5} 0.16 24.4 Bali P. renschi (FRANC) 1 230 19.17 3.82 0.750 54 closed - Sumbawa P. schneideri (I. ReNscH) 22 = 3.99+0.148 | 5.95+0.151 | 0.669+0.0113 4h crack to over Malkong (3.01-5.82) | (5.10-7.91) | (0.588-0.774) | (43-6) closed 20 Vikaiku 1 | - | 4.38 0.705 44 crack - Buja Kori a re s 3.36+0.084 | 5.52+0.108 | 0.608+0.0161 434 crack = (3.20-3.60) | (5.23-5.69) | (0.563-0.632) | (44-44) Diagnosis: Shell very large, diameter 5.10 to 7.91mm (mean 5.95mm), with 43 to 6 rather tightly coiled whorls. Apex and spire moderately to very strongly ele- vated, spire not rounded above, spire protrusion more than one third body whorl width, H/D ratio 0.588 - 0.774 (mean 0.669). Apical whorls 13 to 13, sculpture of curved, slightly retractive, close-set radial ribs, whose interstices are about equal to their width, plus distinctly smaller spiral ribs. In worn specimens this approximates a “pit- ted” sculpture. Postnuclear whorls with low, rather irreg- ular, strongly protractively sinuated radial ribs, about 145 on the body whorl, whose interstices are 3 to 6 times their width. Microsculpture of rather coarse radial riblets with exceedingly fine spiral reticulation and a secondary sculp- ture of broad, widely spaced spiral cords. Where the spiral cords cross the radial ribs and riblets, a “beaded” effect results. Suture impressed, whorls slightly shouldered above, outer and basal margins evenly rounded. Umbilicus completely closed, a slight crack, or a very narrow opening contained more than 20 times in the diameter. Color light yellow-white with frequent radial reddish flammulations that coalesce over much of the shell spire. Aperture sub- circular, slightly shouldered above, with evenly rounded outer margins, basal margin extended flatly to columella. Columellar lip thickened by white callus, reflected and twisted to close umbilicus, adults with a distinct columel- lar-basal angle. Aperture inclined about 15° from shell axis. Table 4 Size and Shape Variation in Paryphantopsis Specimens Examined N umber of P. platycephala 3.04 + 0.042 (2.94-3.14) 3.41 +0.074 (3.01-3.79) P. fultoni Diameter 4.93+0.188 | 0.618+0.0171 + (4.71-5.49) | (0.571-0.653) | (23-22) 8.52+0.127 | 0.401+0.0098 28 (7.97-9.28) | (0.354-0.434) (28-3) Page 254 THE VELIGER Vol. 12; No. 3 Pilsbrycharopa schneideri is very large, with a nearly closed or closed umbilicus, protruding spire, and altered radial sculpture. Pilsbrycharopa gressitti and P. nigrofusca have much finer sculpture, open umbilici and much less elevated spires. Other Pilsbrycharopa are much, much smaller in size. Paratypes: New Britain: (ZMB, FMNH 146031). Malkong Material: New Britain: Malkong (30 specimens, ZMB, FMNH 146031). Vikaiku, village on Angabunga or St. Joseph River, inland from Hall Sound (2 specimens, MH NG collected by Lamberto Loria in July 1892) ; Bujakori, village along Kemp Welch River, northeast of Rigo (9 specimens, MHNG, FMNH 159264, collected by Lam- berto Loria in August 1890). Remarks: Pilsbrycharopa schneideri differs from the other New Guinea species in its very elevated spire, having the radial apical sculpture primary, the flared baso-columellar lip, closed or cracked umbilicus, irregular radial ribbing, and very strong secondary spiral cording. The Indonesian P. renschi and P. baliana are very similar in general ap- pearance, but have typical endodontid radial ribs and a less specialized apical sculpture. Paratypes from Malkong came from river drift piles and showed considerable variation in size and shape (Table 3). Both the Vikaiku adult and 4 Bujakori examples fall within the range of variation shown by this set. I can see no sculptural differences between the shells and do not hesitate to consider them conspecific. Adult shells can be recognized by the angled baso-columellar margin and generally closed umbilicus. Juveniles have a rounded mar- gin and slightly open umbilicus. I. Renscu (loc. cit.) gave outline figures of the termi- nal genitalia and radular teeth. Apparently there is no epiphallic diverticulum as in Pilsbrycharopa gressitti, and the illustrated vas-deferens-epiphallic union seems pecul- iar. Without study of the penis interior and verification of the epiphallic diverticulum absence, I would hesitate to separate this species from Pilsbrycharopa. Paryphantopsis THIELE, 1928 Zool. Jahrb., Syst. 55: 125 - 126. Medium sized to very large Charopinae in which the apical sculpture varies from a lattice of co-equal radial and spiral riblets to distinctly pitted surface. Whorls very loosely coiled, generally about 3, rarely more. Spire nor- mally slightly raised, flat in many species. Umbilicus nor- mally closed, narrowly open laterally only in Paryphantop- sis dauloensis and P. sculpturata. Radial sculpture reduced to periostracal fringes in most taxa, remnants of major radials in P striata and P. louisiadarum. Whorls keeled in P elegans and P. fultoni, rounded in other species. Anato- my known only in one species. Pallial cavity shortened, hindgut and kidney separating early, arms of ureter widely spread, pulmonary vein markedly branched. Terminal genitalia with short penial retractor muscle, tapering short penis with vergic papilla and large corrugated pilasters, a long epiphallus and epiphallic diverticulum. Type species: Flammulina (Paryphantopsis) lamelligera THIELE, 1928 by OD. Except for the material of Paryphantopsis fultoni and P. platycephala reported on below, no species of this genus is known from more than 3 specimens. Variation in 4 adults of P platycephala and 9 P fultoni is summarized in Table 4. Obviously we have only the most rudimentary know- ledge of intra-populational variation. This makes it impos- sible to attempt a formal revision on the species level. I have examined the types of all but Paryphantopsis similis THIELE, 1928, P lamelligera Tueve, 1928 and P. globosa (HEDLEY, 1890). Type specimen descriptions are pre- sented for species described prior to the work of van BENTHEM JuTTING (1964, pp. 13-17), but her species are well defined and easily identifiable. Table 5 summarizes available data on species characters. The taxa show differing combinations of relatively few changes in character states. Paryphantopsis fultoni and P elegans are immediately recognizable because of their sharp peripheral keels; P lowisiadarum and P. striata by the lack of periostracal fringing on the ribs. Otherwise the differences are in size, spire and apex elevation, body whorl descension and presence or absence of an umbilical chink. These are comparatively minor changes and the general appearance of Paryphantopsis species is very similar. No specimens have been taken in the fairly well col- lected Vogelkop or Biak Island areas of Irian. All known species have been collected between about 139° E near the Idenburg River of Irian to Rossel Island, Louisiades, Papua. Specimens of Paryphantopsis fultont, P. platyceph- ala and a shell tentatively identified as P globosa have been taken near Moroka on the Laloki River, Papua; P. filosa and P. sculpturata above the Idenburg River; P Jatior and P. arcuata in the Star Mountains of Irian. Apparently there is some sympatry or near sympatry within the genus. Members of the last two species pairs were taken at dif- ferent elevations, but within a few miles of each other. Judgment of distribution and speciation patterns must Vol. 12; No. 3 THE VELIGER Page 255 Table 5 Type or Mean Adult Characters in Paryphantopsis S 3 $8 se] § A 3 mT: z Be Si | s = a oa $3 4 Se Sel | Ss oe ae 5 Paryphantopsis (P) filosa 2.7 0.750 Ton Raised Strongly Closed eed Pyamaca spon] Clas arcuata 8 | 0646 | 3 Raised || Closed sculpturata 3.3 0.705 Slightly Open Raised similis 0.700 Raised Closed platycephala Type 2.7 Flat Slight Closed Moroka 3.04 Flat Slight Closed dauloensis 3.26 Raised Yes uk Open eile elegans 2.55 Raised No Closed latior Flat | Rapid | Closed lamelligera Raised Yes Closed striata 5.40 Raised Rapid Closed fultoni 3.40 Slightly No Closed Raised loutsiadarum 6.50 Flat Yes Closed P. (Gallodema) globosa 4.44 | 5.95 Raised Raised Yes Crack (Moroka Juvenile) Original Description | 10.0 | 12.0 Raised Raised Yes Open await much larger and geographically more diverse samples. Recognition of species group is equally premature, with only the single species, Paryphantopsis dauloensis, dis- sected. An exception concerns the position of the shell described as Rhytida globosa Hepiey, 1899. IREDALE (1941, p. 92) proposed a generic name, Gallodema, and suggested it might be “an aberrant Zonitid” or a pary- phantid. He also described the genus Illonesta for Pary- phanta louisiadarum MOLLENDORFF, 1899, having over- looked the description of Paryphantopsis THIELE, 1928. As can be seen from Table 5, HEpLEy’s species differs greatly in size, whorl count and major sculpture from the typical Paryphantopsis. In apical sculpture, however, it is intermediate between Paryphantopsis and the more speci- alized Pilsbrycharopa, and the largest Paryphantopsis are nearer in size than the largest Pilsbrycharopa. Pending availability of further material for dissection, I prefer to classify HEpLEy’s species as a Paryphantopsis, but use Gallodema as a subgeneric name. No key to the species is attempted, since simple com- parison of the measurements and variable shell features with the data in Table 5 will indicate which are the most similar morphotypes. Species are listed in ascending order of size. Comments are restricted to addition of new or supplemental data. For most species I have included only references to pre- vious literature. Paryphantopsis (Paryphantopsis) filosa vAN BENT- HEM JuTTING, 1964 Paryphantopsis filosa VAN BENTHEM JUTTING, 1964, Nova Guinea, Zool., 26: 14-15; figs. Page 256 THE VELIGER Vol. 12; No. 3 16-19 — Araucariakamp at 800 m elevation, south of Idenburg River, near Vlakke Peak, north side Snow Mts., Irian (ca. 139°10’ E, 3°30’S). Paryphantopsis (Paryphantopsis) pygmaea (Bavay, 1908) Helicarion pygmaeus Bavay, 1908, Nova Gui- nea, Zool., 5: 286 - 287; plt. 14, figs. 14, a, b, c — Cyclopis montern Novae Guineae (= Cyclops Mts., near Hollandia, West Irian, ca. 140°35’ 1%, DBO So Paryphantopsis pygmaea (BAvAy), VAN BENT- HEM JutTTING, 1964, Nova Guinea, Zool., 26: 13 - 14. Paryphantopsis (Paryphantopsis) arcuata VAN BENT- HEM JuTTING, 1964. Paryphantopsis arcuata VAN BENTHEM JUT- TING, 1964, Nova Guinea, Zool., 26: 16; figs. 24-27 — Nimdol, bivak 36 at 1220 m eleva- tion, Star Mountains, Irian (ca. 140°48’ E, 4°54’S). Paryphantopsis (Paryphantopsis) sculpturata vAN BENTHEM JuTTING, 1964 Paryphantopsis sculpturata VAN BENTHEM Jurtinc, 1964, Nova Guinea, Zool., 26: 14; figs. 12-15 -— Rotankamp and Tussenkamp at 1100 - 1 200 m elevation, south of Idenburg River, near Vlakke Peak, north side Snow Mts., Irian (ca. 139°10’ E, 3°30’ S). Paryphantopsis (Paryphantopsis) similis (THIELE, 1928) Flammulina (Paryphantopsis) similis THiE.e, 1928, Zool. Jahrb., Syst., 55: 127; plt. 5, figs. 12, a — Maeanderberg, Upper Sepik River, Sepik District, New Guinea (ca. 147°40’ E, 6°30’S). Paryphantopsis (Paryphantopsis) platycephala vAN BENTHEM JUTTING, 1964 Paryphantopsis platycephala vAN BENTHEM Juttine, 1964, Nova Guinea, Zool., 26: 16-17; figs. 28-31 — Doormanpad bivak at 1410m elevation, above Doorman River, Upper Mam- beramo drainage, West Irian (ca. 138°30’ E, 3) es fS)))e Material: Papua, Moroka, headwaters of Laloki River, east of Port Moresby, Central District (10 specimens, MH NG, FMNH 159262). Remarks: Four adults and six juveniles from near Moro- ka, collected by Lamberto Loria in 1893, are tentatively referred to Paryphantopsis platycephala. They are nearest to this species, although showing some differences from the type in height and H/D ratio. Variation in the few adults is summarized in Table 4. Paryphantopsis (Paryphantopsis) dauloensis, SoLEM spec. nov. (Figures 1 a to 1c; 2a to 2e) Diagnosis: Shell slightly smaller than average, diameter 5.36mm to 5.59mm (mean 5.48mm), with 3 to 34 loosely coiled whorls. Apex and spire barely to moderately and evenly elevated, body whorl descending moderately to much more rapidly, H/D ratio 0.577-0.612 (mean 0.595). Apical whorls 14, rounded, sculpture of rather vague radi- al and spiral riblets producing a weakly pitted appearance by partial fusion and wear. Postnuclear whorls with irreg- ular growth wrinkles, many with prolonged periostracal extensions, frequency and prominence of extensions re- duced on shell base. Microsculpture mostly absent, occa- sionally visible under 96 magnification as fine radial and slightly finer spiral riblets. Sutures deep, whorls strongly rounded above, compressed laterally above and below rounded periphery. Umbilicus narrowly and later- ally open, rolled reflection of columellar lip partly con- stricting opening. Aperture very large, subcircular, com- pressed laterally above and below rounded periphery, inclined about 40° from shell axis. The open umbilicus, absence of spiral pitting on the - postnuclear whorls, reduced fringing and weak apical sculpture separate Paryphantopsis dauloensis from pre- viously described species. Paryphantopsis latior VAN BENT- HEM JUTTING has a flat apex and spire, closed umbilicus and is almost 1 mm larger in mean diameter; P similis has a closed umbilicus, is smaller, much higher and has the periostracal fringes much more prominent; P sculp- turata has an open umbilicus, prominent spiral pitting on the lower whorls, and is almost 1 mm smaller in mean diameter. Description: Shell smaller than average, with 3 loosely coiled whorls. Apex and spire slightly protruding, body whorl descending more rapidly, H/D ratio 0.577. Apical whorls 14, evenly rounded, surface cracked and partially obscured by fungus, sculpture of low radial and spiral riblets of equal size, tending towards a pitted appearance. Postnuclear whorls with irregular radial growth wrinkles, many with prominent periostracal extensions. Microsculp- ture occasionally visible as fine radial and slightly finer spiral riblets, surface usually smooth. Sutures deep, whorls strongly rounded above, compressed laterally above and below rounded periphery. Color reddish-brown, becoming Vol. 12; No. 3 yellow-brown near apex. Umbilicus narrowly and later- ally open, periostracal reflection of columellar lip covering opening in direct bottom view. Aperture very large, in- clined about 40° from shell axis, margin only weakly sinuated. Height of holotype 3.09 mm, diameter 5.36 mm. Holotype: New Guinea: Daulo Pass, Eastern Highlands at about 8200 feet elevation. Collected by J. Linsley Gressitt on June 13, 1955. Bernice P. Bishop Museum. Range: Known only from the type collection. Material: Daulo Pass (2 specimens, BPBM). Remarks: Of the previously described Paryphantopsis, only P sculpturata vaN BENTHEM JUTTING has a partly open umbilicus. It is smaller, higher and has prominent spiral sculpture on the lower whorls. Description of the soft parts: Foot and tail shorter than in Pilsbrycharopa. Sole broad and transversely corrugated. Pedal grooves high on foot, deeply impressed, suprapedal less conspicuous, both united over tail, no caudal horn or middorsal groove present. Slime network typical. Gono- pore position not observed. Body color iridescent yellow- white with a very faint reddish tint (caused by preserva- tive?). Mantle collar thick and with low lobes, but no glandular extension onto pallial roof. Pneumostome masked by swellings on mantle edge. Anus opening just inside pneumostome, external ureteric pore lying right beside anus. Pallial region (Figure 2 a) measures 2.96 mm from edge of mantle collar to peak of kidney, distance from anterior end of kidney to mantle collar about 1.50 mm. Lung roof clear of granulations. Kidney bilobed, lobes almost equal in length, high in center, slanting back- wards under intestinal looping beyond end of pallial ca- vity. Posterior portion of kidney sharply angled down from hindgut and parietal-palatal margin. Ureter reflexed, complete, lung roof visible between arms of ureter, tube not tapering, compressed at point of reflection. Heart large, more than two thirds length of pericardial kidney arm, slightly hidden posteriorly by margin of kidney. Principal pulmonary vein very inconspicuous, without major branch- ing after initial bifurcation. Hindgut departing from ure- ter 1.4mm behind anus. Apical genitalia not seen. Pros- tate and uterus as in Pilsbrycharopa. Vas deferens (Figure 2b, VD) large at first, becoming very slender, entering epiphallus at swollen head after being coiled once around penis at muscle sheath. Epiphallus (E) with swol- len head, long lateral diverticulum (EL), and long, coiled tube leading to penis head. Diverticulum equal in length to epiphallic head (Figures 2 c, 2d). Penial retractor (PR) arising from diaphragm, very short, inserting on epiphallic tube near entrance to penis. Penis (P) about 1.9mm THE VELIGER Page 257 long, club-shaped, gradually tapering, basal third a slender tube with muscular sheath. Internally (Figure 2 e) with short vergic papilla (PV) with central groove, sheath of verge attached to one wall of penis, other walls with cor- rugated longitudinal pilasters (PP) tapering into atrium. Atrium (Y) very short, rather broad. Free oviduct (UV) short, internally with longitudinal pilasters, opening into vagina. Spermatheca (S) with basal portion a muscular tube exceeding in diameter free oviduct, narrowing at base of prostate-uterus to slender tube passing up prostate sur- face, head club-shaped, gradually expanding, lying slight- ly above apex of prostate-uterus. Vagina (V) greatly ex- panded, with very thick glandular walls. Free muscle system without unusual features. Jaw of narrow plates, length 5 or 6 times width, fused centrally and tightly joined out to margins. Width about 0.10 mm to 0.11 mm, length not determined since jaw broken in mounting. Central slightly smaller than 1* lateral, mesocone cusp barely projecting beyond basal plate. Laterals 10 to 12, 1* about 10 wide, 13 w long, cusp projecting beyond end of basal plate. Ectocones and endocones all smaller than in Pilsbrycharopa. Marginals with square basal plates, 7 to 8 in number, single ectocone and endocone two thirds length of mesocone. (Based on two broken specimens extracted from shell and broken off in process). Paryphantopsis (Paryphantopsis) elegans (FuttoN, 1902) Paryphanta elegans Futon, 1902, Ann. Mag. Nat. Hist., (7). 9: 182 - 183 — Arva (=Aroa) River, New Guinea. Illonesta elegans (FULTON), IREDALE, 1941, Austral. Zool., 10 (1): 93. Paryphantopsis (Paryphantopsis) elegans (FuLToN), Sotem, 1958, Arch. f. Mollusk., 87 (1-3): 23; 1959, loc. cit., 88 (4-6): 156. Description: Shell of average size, with 3 very loosely coiled whorls. Apex and spire slightly and evenly elevated, last whorl not descending more rapidly, H/D ratio 0.438. Apical whorls 13, sculpture of crowded, minute, oval to circular pits caused by fusion of radial and spiral riblets, with a nearly medial keeled ridge that fades out after nuc- lear whorls. Postnuclear whorls with low, irregular, pro- tractively sinuated growth wrinkles, occasionally with la- mellar periostracal extensions. Peripheral keel possessing a serrated periostracal fringe. Occasional traces of minute, vague pits arranged in spiral patterns. Microsculpture of fine, rather widely spaced radial riblets with faint traces of very fine and crowded spiral riblets. Sutures deep, channeled, whorls flatly rounded with stronger spiral Page 258 THE VELIGER Vol. 12; No. 3 sculpturing yisible, particularly strongly pitted within a- perture. Color dark olive yellow brown with irregular lighter streaks. Apex light yellow orange in tone. Umbili- cus closed by reflection of lip. Aperture very large, subtri- angular, almost flat above periphery, gently and evenly rounded below, with very sinuated edge, inclined almost 50° from the shell axis. Height of holotype 2.55 mm, diameter 5.82 mm. Holotype: Papua: Arva (= Aroa) River at 6000 feet elevation. British Museum (Natural History) number 1907.5.28.11. Range: Known only from the type collection. Material: Arva River (3 specimens, BMNH 1907.5.28.11, SMF 161111, ANSP 109258). Remarks: The much larger Paryphantopsis fultoni has a flat spire and lacks any trace of postapical spiral puncta- tions. No other species have a sharp peripheral keel. Paryphantopsis (Paryphantopsis) latior VAN BENTHEM JuTTING, 1964 Paryphantopsis latior VAN BENTHEM JuTTING, 1964, Nova Guinea, Zool., 26: 15 - 16; figs. 20 - 23 — Ok Minan, beyond bivak 39A at 1450 to 1500m elevation, Star Mountains, Irian (ca. 140°48’43” E, 4°54’32”S). Paryphantopsis (Paryphantopsis) lamelligera (THIELE, 1928) Flammulina (Paryphantopsis) lamelligera THir.e, 1928, Zool. Jahrb., Syst., 55: 126; plt. 5, figs. 10, a — Maeanderberg, 670m elevation, Upper Sepik River, Sepik District, New Guinea (ca. 147°40’ E, 6°30’S). Paryphantopsis (Paryphantopsis) striata (Futon, 1902) Paryphanta striata Futton, 1902, Ann. Mag. Nat. Hist., (7), 9: 182 — Arva (=Aroa) River, New Guinea. Flammulina (Paryphantopsis) striata (Fuuton), Ture, 1928, Zool. Jahrb., Syst., 55: 126; plt. 5, fig. 11. Illonesta striata (FULTON), IREDALE, 1941, Austral. Zool., 10 (1): 93. Paryphantopsis (Paryphantopsis) striata (Futon), SoteM, 1958, Arch. f. Mollusk., 87 (1-3): 23. Description: Shell very large, with 34 loosely coiled, globosely swollen whorls. Apex and spire moderately and evenly elevated, body whorl descending only slightly more rapidly, H/D ratio 0.707. Apical whorls 13, sculpture of widely spaced, approximately equal radial and spiral rib- lets, forming a cross-hatch sculpture except in the sutural area where the spiral ribbing is absent. Secondary sculp- ture of very fine radial ribbing, barely visible. Postnuclear whorls with narrow to low, broadly rounded, vague growth wrinkles, occasionally prolonged into periostracal lamellae. Microsculpture of very fine, crowded, radial riblets crossed by slightly finer spiral riblets. Color reddish brown with irregular orange-yellow periostracal streaks, apex light yellow orange. Sutures deep, whorls strongly rounded above, flattened latcrally above periphery, with flattened and elongated basal margin. Umbilicus closed. Aperture very large, somewhat flattened laterally above periphery and on basal margin, inclined about 30° from the shell axis, with very sinuate lip edge. Height of holotype 5.69 mm, diameter 8.04 mm. Holotype: Papua: Arva (—Aroa) River at 6000 feet elevation. British Museum (Natural History) number 1902.5.28.10. Range: Known only from the type collection. Material: Arva River (2 specimens, BMNH 1902.5.28.10, SMF 161110). Remarks: The apical sculpture of widely spaced radial and spiral ribs which form a cross-hatch pattern, is an obvious forerunner of the minutely pitted sculpture of Paryphantopsis louisiadarum. In the latter the pattern of pitting carries over onto the postnuclear whorls, but is totally absent in the few specimens known of P striata. The lack of periostracal fringes is shared with P lowisia- darum, which differs in its larger size, pitted apical sculp- ture and less rapid body whorl descension. Paryphantopsis (Paryphantopsis) fultoni (Corn, 1922) Chronos fultont Corn, 1922, Ann. Mus. Civico Stor. Natur. Giacomo Doria, (3), 9: 361 - 363; figs. 3-4 — Moroka, New Guinea. Diagnosis: Shell very large, diameter 7.97 mm to 9.28 mm (mean 8.52 mm), with 23 to 3 very loosely coiled whorls. Apex distinctly elevated, spire flat, body whork not des- cending more rapidly, H/D ratio 0.354 to 0.434 (mean 0.401). Apical whorls 14, bi-keeled, flat above supraperi- pheral keel, a marked supraperipheral sulcus, followed by a rounded peripheral keel, sculpture of minute pits ar- ranged in spiral rows. Postnuclear whorls macroscopically smooth above periphery except for irregular malleations, growth wrinkles, and occasional periostracal extensions. Periphery with very large and irregular periostracal fringe, — Vol. 12; No. 3 lower palatal wall with regularly spaced, crowded, nar- row, prominent periostracal rib extensions. Under 96 magnification traces of micro-radial riblets and finer mi- crospiral riblets are visible on upper surface, clearly defined on lower surface of shell. Sutures deep on apex, becoming very shallow on spire, apical whorls bikeeled, lower whorls becoming strongly flattened laterally above sharply keeled periphery, with evenly rounded lower palatal margin. Columellar lip recurved over and closing very narrow umbilical chink even in juveniles. Aperture very large, flattened laterally above periphery, inclined more than 50° from shell axis. The keeled periphery, very prominent periostracal fring- ing, absence of spiral pitting below the apex, and large size identify Paryphantopsis fultoni; P elegans (FULTON) has the keeled periphery and fringes, but is much smaller (diameter 5.82mm), has spiral pitting on the lower whorls, and the sutures deep even to the aperture; P lamelligera (THIELE) has only a very weak peripheral keel, much stronger spire and apical elevation with marked descension of the body whorl. All other Paryphantopsis have rounded peripheries. Description: Shell very large, with 2% very loosely coiled whorls. Apex slightly protruding, spire flat, body whorl not descending, H/D ratio 0.424. Apical whorls slightly less than 14, flattened above mid-upper palatal keel, con- cave below to peripheral keel, sculpture of minute punc- tations formed by fusion of spiral and radial ribs. Post- nuclear whorls with irregular growth wrinkles, sometimes bearing periostracal fringe extensions, surface somewhat malleated with remnants of apical keels and sulci, peri- phery with roughly triangular, quite large periostracal fringes, lower palatal wall with narrow, high, rather crowded, regularly spaced radial periostracal rib exten- sions. Microsculpture visible on lower surface as fine radials crossed by finer spirals, barely visible on upper surface. Sutures deep on apex, becoming quite shallow on lower spire, postnuclear whorls flattened laterally above sharply angled periphery, evenly rounded below. Color reddish brown near aperture, becoming greenish yellow on upper spire, apex yellow-white. Umbilical chink closed by reflection and periostracal extension of columellar lip. Aperture very large, flattened laterally above periphery, inclined about 50° from shell axis. Height of lectotype 3.46 mm, diameter 8.11 mm. Lectotype: Moroka, Laloki River, headwaters, east of Port Moresby. Collected by Lamberto Loria in July 1893. Museo Civico di Storia Naturale “Giacomo Doria,” Genova. Material: Moroka (19 specimens, MHNG, FMNH 159265). THE VELIGER Page 259 Remarks: Differences from Paryphantopsis elegans are covered in the diagnosis above. Probably the most signifi- cant are the absence of spiral sculpture on the lower whorls and regular fringed sculpture on the shell base seen in P fultoni. Moroka is a classic ornithological col- lecting locality on the slopes of Mt. Wori-Wori about 25 miles inland of Tupuseleia and fairly near Port Moresby. Paryphantopsis (Paryphantopsis) louisiadarum (MG6LLENDorr®rF, 1899) Paryphanta louisiadarum MO.LLENDoRFF, 1899, Nachr.-Bl. dtsch. Malak. Gesell., 31: 89 — Louisiade Islands, New Guinea; MOLLENDorFF, 1902, Syst. Conch: ‘Cab:, I-12; B, p: 17; pit. 3 figs: 1-3; SoteM, 1959, Arch. f. Mollusk., 88 (4-6) : 156; plt. 12, figs. 10, 11; plt. 13, fig. 6. Illonesta louisiadarum (MO6OLLENDORFF), IREDALE, 1941, Austral. Zool., 10 (1): 93. Paryphantopsis (Paryphantopsis) louisiadarum (MOLLENDoRFF), SoLem, 1958, Arch. f. Mollusk., 87 (1-3): 23 — Rossel Island, Louisiades. Description: Shell very large, with 2% very loosely coiled, globosely swollen whorls. Apex nearly flat, lower whorls descending moderately, H/D ratio 0.704. Apical whorls 13, sculpture a network of spiral and radial ribs broadly joining each other, forming regular rows of small circular to oval pits, about 15 in number across the whorl. Pitted sculpture continuing on post nuclear whorls with radial ribbing gradually becoming more prominent and at the end of the second whorl a fine microsculpture of radial riblets crossed by much finer and more crowded spiral rib- lets becoming visible. On the body whorl the sculpture has become reduced to series of spiral grooves in which the small pits are visible with most of the surface showing irregular growth lines and microsculpture. Color olive yellow brown with occasional darker flammulations be- coming very dark in the sutures. Umbilicus closed by reflection of lip. Aperture very large, somewhat flattened laterally above periphery and on basal margin, inclined about 35° from the shell axis. Height of lectotype 6.54 mm, diameter 9.28 mm. Lectotype: New Guinea: Louisiade Islands. Natur-Mu- seum Senckenberg, Frankfurt number 137274. Range: Louisiade Islands. Material: Rossell Island (1 specimen, ANSP 109257) ; Louisiades (2 specimens, SMF 137274, SMF 165564). Remarks: Only the sharply keeled Paryphantopsis fultoni approaches the size of this species. No anatomical material Page 260 is available and apparently no specimens have been col- lected in this century. Paryphantopsis (Gallodema) globosa (HEDLEY, 1890) Rhytida globosa Hepiey, 1890, Ann. Rep. British New Guinea, 1888 - 89: 65 — Mt. Victoria, Owen Stanley Mts., Papua; Hepiey, 1891, Proc. Linn. Soc. New South Wales, (2), 6: 80; plt. 10, figs. 15, 16; Sorem, 1959, Arch. f. Mollusk. 88 (4-6): 156 tomlaye Gallodema globosa (Hepiry), IREpALE, 1941, Austral. Zool., 10 (1): 92. Paryphantopsis (Gallodema) globosa (HEDLEY), Sotem, 1958, Arch. f. Mollusk., 87 (1-3): 24 Remarks: I have not been able to examine the type of Rhytida globosa, which was deposited in the Queensland Museum, Brisbane. The original description mentioned the pitted apical sculpture and “bleached” early whorls. A single shell from Moroka (MHNG) collected by Lam- berto Loria in July, 1893, is referred to this species, al- though much smaller in size. It is 4.44 mm high, 5.95 mm in diameter, H/D ratio 0.747, with 33 whorls. HEDLEy’s original measurements of height 10 mm and diameter 17 mm give a calculated H/D ratio of 0.588, but the original figures give a height of 10.9mm, diameter 15.9 mm for a calculated H/D ratio of 0.686. I consider that the Moro- ka shell is closely related to HEDLEY’s species, if not merely a juvenile example. Apical sculpture of the Moroka shell consists of co- equal radial and spiral riblets that produce a lattice pat- tern with a few worn spots appearing “pitted” as in typical Paryphantopsis. IREDALE (loc. cit.) sketchily de- scribed a new genus, Gallodema, for this species. It is intermediate between Pilsbrycharopa and Paryphantopsis in shape and whorl count. The apical sculpture also ap- pears transitional. I question the desirability of generic separation and prefer to use Gallodema as a subgenus of Paryphantopsis. COMPARATIVE REMARKS Despite knowing only part of the visceral hump anatomy for one species in each genus, a comparison between the two yields significant information on patterns of pulmonate evolution. Pilsbrycharopa and Paryphantopsis belong to the same subfamily. They have quite different average patterns of shell structure. The two dissected species, Pilsbrycharopa gressitti and Paryphantopsis dauloensis, THE VELIGER Vol. 12; No. 3 are sympatric. Therefore existing genital differences may provide no information helpful in elucidating phylogeny. In the Pacific Island endodontid taxa, sympatric species in the same genus or closely related genera show marked character displacement in penial structures (unpublished data). One species of such a pair or group may be strikingly altered in penis structures, while the other(s) may be only very slightly modified, or they may diverge in different directions from the “‘average” structural pattern. I cannot state whether the Pilsbrycharopa or the Pary- phantopsis is greatly modified, since without dissection of many specics, determination of the average pattern is not possible. Pilsbrycharopa gressitti has an oval penis, lacks a vergic papilla, has a large stimulatory pad and large smooth pilasters near the base, while Paryphantopsis dau- loensis has a club-shaped penis with a vergic papilla, no stimulatory pad, and corrugated longitudinal pilasters. The existence of these differences may have phylogenetic sig- nificance or may reflect character displacement to enforce species isolation. A hint of possible ecological divergence is given by the body color, yellow-white in Paryphantopsis, greyish tones in Pilsbrycharopa. In the Pacific Island en- dodontids, yellow-white body color is associated with litter dwelling forms, greyish tones with semiarboreal taxa. No ecological data have been recorded concerning the habitat of either genus, but general affinities of both seem to be with the Pacific Island, rather than the New Zealand- Australian taxa. Correlation of ecological zonation and body color reasonably could be expected to hold for the New Guinea taxa. A combination of slight ecological di- vergence and exaggeration of species isolating mechanisms is the common pattern when closely related species become sympatric. A possible hint of dietary difference is given in the radular teeth. Those of Paryphantopsis have the basal plates of the laterals much narrower and the mar- ginal basal plates are square rather than rectangular. Mesoconal cusps are shorter in Paryphantopsis and there is no evidence of ectoconal cusp splitting on the outermost marginals. This shift in radular tooth shape and cusp size may indicate a scraping feeding action rather than the normal slicing action in more typical endodontid radulae. Ecological and life history observations in the Daulo Pass area on the two genera could yield very important data on the origin and maintenance of mating barriers in pulmonates. Both genera also have been collected at Moroka. While the above data concerning such factors of micro- evolution are interesting, differences between the two gen- era provide deeper insights into patterns of major change. A look at the shell illustrations of the two new species (Figure 1) and mean measurements (Tables 2, 3, 5) con- firms the existence of several consistent differences in Vol. 12; No. 3 THE VELIGER Page 261 Gf? ila Gy E ® ®) Figure 3 Visceral hump volume relationships and foot length-pallial cavity ratios in Pilsbrycharopa (a) and Paryphantopsis (b) Page 262 coiling pattern, shape and sculpture. Table 6 summarizes the major contrasting shell features between the two gen- era. There is some overlap in umbilical width and apical sculpture, plus considerable overlap in diameter, but the basic contrast in structure and form is obvious. Within the context of the Endodontidae, the characteristics of Paryphantopsis represent much greater departures from the typical structural pattern. “Cope’s Law” concerning the general tendency towards size increase during a phylo- genetic series is consistent with the greater size of Pary- phantopsis. Within the subfamily Charopinae, spiral apical cording is primitive. Addition of radial elements clearly is second- ary. The increase in radial apical sculptural elements in the species group of Pilsbrycharopa is correlated with larger size. The peculiar “pitted” apical sculpture of Pary- phantopsis (sce SoLeM, 1959, plt. 13, fig. 6) is most easily derived from partial height reduction of a radial and spiral rib network. It is a secondary derivation after radial clements are large enough to equal the spiral cording. Paryphantopsis is much more specialized in apical sculpture. The most significant alteration is the reduction in whorl count and correlated change in coiling pattern seen in Paryphantopsis. While accurate area measurements could not be made, casual inspection shows that the apertural cross-sectional area is much less in the 4- to 5-whorled Pilsbrycharopa (Figure 1, e) than the 3-whorled Pary- phantopsis (Figure 1, b). It is equally obvious that, in shells of equal diameter, lowering the whorl count will significantly lower the total linear distance from the lip edge to shell apex as measured along either the periphery or midwhorl line. Using the illustrations of Pilsbrycharopa gressitti and Paryphantopsis dauloensis as examples and adjusting for the size differences, the distance in the Paryphantopsis is only 73% of the measured midwhorl distance in the Pilsbrycharopa. The shell serves to encom- pass the visceral hump and provides space for withdrawal of the head, foot and tail, so that alterations in shell form cannot be segregated from a consideration of changes in the anatomy. Actually, since the shell is deposited by the mantle edge of the living snail, it is fallacious to think of the two separately. Practically speaking, however, chan- ges in the shell form are more easily perceived and docu- mented so that an initial explanation of the changing surface cover (=shell) of the visceral hump permits better understanding changes in organs of the latter. The net effect of a reduction in whorl count and loosen- ing of the coiling patterns is shown in Figure 3. If the two visceral humps could be decoiled and distorted into simple cones, the volume would change only slightly, but the spire angle would be enlarged, the height of the cone THE VELIGER Vol. 12; No. 3 shortened, and the aperture widened in Paryphantopsis. There is no doubt that Paryphantopsis has a shorter, wider area for the visceral hump organs. Since this pattern of reduction in whorl count and loosening of coiling pattern is repeated in family after family of land snails and is an initial step in the process by which snails evolve into slugs, examination of the anatomical changes in the vis- ceral hump region between Pilsbrycharopa and Paryphan- topsis is worthwhile. When combined with similar studies in other taxa, such work may provide criteria for evalu- ating the affinities of slugs. In this report I wish to focus on two organ complexes, the entire pallial region and the genitalia. Unfortunately I could not examine the apical genitalia of either genus, but changes in this area are fairly standard. Pallial regions of both genera are illustrated in Figures 2a and 2f. Since the mean diameter of Pilsbrycharopa gressittt is 6.76 mm and the mean diameter of Paryphan- topsis dauloensis is 5.48 mm, or 19% less, direct measure- ment comparisons are less meaningful than the use of ratios. Total length of the pallial cavity in Pilsbrycharopa is 6.25 mm (0.92 shell diameter); 2.96 mm (0.54 shell dia- meter) in Paryphantopsis. While in Pilsbrycharopa it occupies more than one-third of the body whorl, in Pary- phantopsis it is reduced to about one-sixth, or only half the proportionate amount. No accurate measure of pallial cavity width was possible, since the delicate roof tissue on the lower palatal wall is inevitably torn during dissection and further cut in pinning the cavity out for detailed study. It undoubtedly is greater, but the organs all occu- py the upper palatal portion and parietal-palatal margin, so that this dimension can be ignored. In most land snails with normally developed shells the hindgut follows the parietal-palatal angle from the anus past the pallial cavity apex. In the Charopinae, the kidney is bilobed, with a rectal lobe lying alongside the hindgut from anterior end to the curved base of the kid- ney and a pericardial lobe extending anterior of and posterior to the heart. Pilsbrycharopa departs from this pattern in that the kidney is partially rotated downwards, with only the anterior third of the rectal kidney arm in contact with the hindgut. This is carried further in Pary- phantopsis, where only the anterior eighth of the rectal kidney arm is along the hindgut. That this is *basically simple rotational change is shown by calculating the width to length ratios for the kidneys, which are 0.69 in Paryphantopsis and 0.65 in Pilsbrycharopa. The difference is within the probable range of measurement error and has no significance. Pilsbrycharopa represents an initial stage in pallial cavity shortening, which is carried further in Paryphantopsis. A more obvious change concerns the spatial relationships of the primary (ascending) and sec- Vol. 12; No. 3 THE VELIGER Page 263 ondary (descending) ureters (KD). In typical Charopi- nae the two branches are either compacted together between the kidney lobes or a narrow strip of lung roof is visible between and a very slight angle is developed. In Pilsbrycharopa the ureter arms are clearly divergent with about a 28° angle. In Paryphantopsis the angle is greatly increased, reaching about 60° in dissected speci- mens. Obviously, continuation of this trend would result in development of a primary ureter transversely oriented in the pallial cavity, essentially paralleling the mantle collar edge. Such an arrangement is present in the Suc- cineidae. The phylogenetic implications of this will be considered in another report. Two additional pallial alterations require comment. In Pilsbrycharopa the external ureteric pore (KX) is located distinctly behind the anal opening (A) ; in Paryphantop- ‘sis the two open side by side at the posterior pneumostomal margin. Pilsbrycharopa has the principal pulmonary vein (HV) simple and unbranched; Paryphantopsis has mul- tiple branches on the pallial roof. From a pallial cavity extending one-half to five-eighths of a whorl apically in most Charopinae, Pilsbrycharopa shows a reduction to one-third of a whorl and Paryphan- . topsis to one-sixth. The proportionate shortening of the pallial cavity reduced the length of the pulmonary vein and hence the surface for both water and gas exchange. Branching of the vein restores balance to the system. Ad- justment of the kidney and ureter to the “squeeze” was achieved by partial rotation of the kidney and opening of the angle between the primary and secondary ureter. This is only one of the many ways to compensate for the changed forms. The species described as Flammulina nigrescens VON MOLLENDoRFF (1900, pp. 107-109) from Ponape, Caroline Islands has a shell form very similar to that of Paryphantopsis, but the pallial region is very dif- ferent. In that species, the very elongated, bilobed kidney has become square in shape, very thick in the middle, the ureter arms right next to each, and the kidney does not deflect from the hindgut (unpublished data). Genital structures of the two genera agree in essentials and differ widely in details. I have dissected over 100 species of endodontids from the Pacific Islands. Pilsbry- charopa and Paryphantopsis differ sharply from all of these in having a diverticulum (EL) on the epiphallus and in having the penial retractor muscle insert on the epiphallus rather than on the head of the penis. Structures of the prostate-uterus, spermatheca and vas deferens agree with the typical Charopinae. The penial differences were out- lined above and are not discussed further. The most ob- .vious difference in the two genera is the length of the penial retractor muscle (PR) — long in Pilsbrycharopa, very short in Paryphantopsis. Since the muscle arises from the diaphragm near the pallial cavity apex, shortening of the cavity shortens the muscle. In Paryphantopsis the epiphallus and vagina are con- siderably longer than in Pilsbrycharopa. At first glance this appears anomalous, since shortening of the visceral hump in the former genus should tend to shorten the genital organs. Unfortunately the complete prostate-uter- ine areas of neither genus were available for study. From dissections of Pacific Island and Thailand taxa, I have learned that shortening of genital organs does not proceed uniformly, but is done on a zonal basis. Hence shortening may be restricted to the prostate-uterine section in this particular Paryphantopsis, but have proceeded in the lower area in the Pilsbrycharopa. The extent and varia- bility of such zonal compaction can be appreciated by comparing the genital anatomy of Durgella libas and Cryptaustenia gadinodromica (see SoteM, 1966, p. 54, fig. 9a; p. 62, fig. 12b). Both have shells of about 4 whorls and very large and elongated feet. In Durgella (loc. cit., p. 54) the prostate-uterus is very long and the free oviduct, spermatheca and penis obviously short; in Cryptaustenia, the prostate and uterus are only slightly longer than the spermatheca and penial complex. Megaustenia siamensis (Ibid., p. 83, fig. 19a) agrees more with Durgella, but has the penial complex convoluted and coiled. All three helicarionid genera represent about 14 whorls reduction from the normal helicarionid pattern. Compaction of genital structures has occurred, but different zones have been affected to different extents. This makes it exceedingly difficult to evaluate differ- ences betwen the genitalia of two species that show par- tial visceral hump reduction, unless considerable data are available concerning the “normal” or “‘typical” structural pattern in species that do not show such shell reduction. Since Pilsbrycharopa and Paryphantopsis show major dif- ferences from Pacific Island genera, 7. ¢., possession of the epiphallic diverticulum, insertion of the penial retractor on the epiphallus, adjustment of the pallial cavity to com- paction by kidney rotation, and internal penial configura- tions, we do not know what the typical pattern is in related genera. SUMMARY Pilsbrycharopa and Paryphantopsis present contrasting patterns of shell structure (Table 6), although they are very similar in anatomy. Changes from the normal charo- pinine pattern in the pallial complex of these genera indi- cate one method of coping with an early stage in visceral Page 264 THE VELIGER Vol. 12; No. 3 Table 6 Shell Differences Between Pilsbrycharopa and Paryphantopsis Pilsbrycharopa Paryphantopsis Whorl count 33 to5+ 23 to 34 Coiling pattern tighter much looser Umbilicus usually widely slight lateral crack or moderately or completely open closed Size of aperture smaller much larger reduced to periostracal fringes spiral and radial Radial sculpture usually typical Apical sculpture spiral cords to equal radials to pitted and spirals Calcification average to below average heavy to slight Diameter 1.9-7.3mm 3.6 - 17.0mm median 3.88 mm | median 5.8 mm hump reduction. If carried to a greater extent, evolution of slug-like forms becomes possible and interpretation of such patterns will aid in determining the affinities of slugs. Pilsbrycharopa contains nine species. When more species can be dissected, it may be broken up into several genera, but in the absence of such data, I prefer to use a single broadly defined generic taxon. Several of the species may be compound taxa. Paryphantopsis contains fourteen nominate units. They are known only from type material and the extent of intra- and inter-populational variation is unknown. LITERATURE CITED ARcHBOLD, Ricuarp, A. L. Rano «& L. J. Brass 1942. _—_ Results of the Archbold Expeditions. No. 41. Summary of the 1938-1939 New Guinea Expedition. Bull. Am. Mus. Nat. Hist. 79 (3): 197 - 288; 3 maps; plts. 1 - 35 BortrTcer, CAESAR R. 1908. Zur Fauna von Amboina (Mollukken). deutsch. Malakol. Gesell. 40 (4): 180 - 192; 6 figs. Corn, Giorcio Sitvio 1922. Nuove descrizione di specie di molluschi del Museo Civico di Genova. Ann. Mus. Civ. Genoa 9 (3) : 359 - 363; Nachr. Bl. 4 figs. Franc, A. 1952. | Remarques suivies de rectifications de nomenclature sur des coquilles Néo-Calédoniennes. Bull. Soc. Zool. France 77: 76-79 Futon, H. 1902. Descriptions of new species of Land-Mollusca from New Guinea. Ann. Mag. Nat. Hist. 9 (7): 182 - 184 HEDLEY, CHARLES 1890. Description of a new Rhytida from New Guinea. Ann. Rep. British New Guinea, 1888-1889: 65 1891. The land-molluscan fauna of British New Guinea. Proc. Lin. Soc. N. S. W, 6 (2): 67-116; plts, 9- 12 IREDALE, TOM 1941. A basic list of the land Mollusca of Papua. Zool. 10 (1): 51-94; plts. 3 - 4. MOLLENDoRFF, O. 1892. Die Landschneckenfauna der Tenimber-Inseln (Timor- laut). Nachr. Bl. deutsch. Malakol. Gesell. 24 (5-6): 81 - 120 plt. 1 Austral, 1899. Neue Arten aus der Strubell’schen Sammlung. _Nachr. Bl. deutsch. Malakol. Gesell. 31 (5): 89-92 1900. The land shells of the Caroline Islands. Journ, Malac. 7 (5): 101 - 126; 5 charts; 3 figs. MOo.venporrr, O. «& W. KoBELT 1902-1905. Die Raublungenschnecken (Agnatha). Erste Ab- theilung: Rhytididae & Enneidae. Syst. Conch. Cab. I, 12, B; 1 - 362; plts. 1-41 RENscH, BERNHARD 1930. | Neue Land-Pulmonaten von den Kleinen Sunda-Inseln. Zool. Anz. 89 (3/4): 73-88; 16 figs. 1932. Die Molluskenfauna der Kleinen Sunda-Inseln Bali, Lombok, Sumbawa, Flores, und Sumba. II. Zool, Jahrb. Syst. 63: 130 pp.; 3 plts.; 56 figs. 1935. Zur Landschneckenfauna von Timor. Sitz. Gesell. Naturf. Freunde Berlin 1935: 311 - 336; 19 figs, RenscuH, I. 1937. | Systematische und tiergeographische Untersuchungen uber die Landschneckenfauna des Bismarck-Archipels. II. Arch. f. Naturgesch., N. F 6 (4): 526 - 644; 54 figs. SmirH, Epcar ALBERT 1896. | On some land shells from New Guinea and other neigh- boring islands, with descriptions of new species. Journ. Malacol. 5 (2): 17-22; plt. 2 SoLtem, ALAN 1958. | Endodontide Landschnecken von Indonesien und Neu Guinea. Arch. Molluskenk. 87 (1-3): 19-26; 6 figs. 1959. On the family position of some Palau, New Guinea, and Queensland land snails. Arch. f. Molluskenk. 88 (4-6): 151 - 158; plts. 12, 13; 2 figs. 1964. A collection of non-marine mollusks from Sabah. Sabah Soc. Journ. II (1-2): 40 pp.; 5 figs. 1966. Some non-marine mollusks from Thailand, with notes on classification of the Helicarionidae. 24: 110 pp.; 3 plts. Soos, L. 1911. On a collection of land shells from New Guinea and adjacent Islands. | Ann. Mus. Hungar. IX: 345 - 356; 10 figs. Spolia Zool. Mus. Haun. THIELE, JOHANNES 1928. Mollusken vom Bismarck-Archipel, von Neu-Guinea und Nachbar-Inseln. Zool. Jahrb. 55: 119 - 146; 1 fig.; plt. 5 VAN BENTHEM JurtiNc, W.S. S. 1964. Non-marine molluscs of W. New Guinea. Part 3, Pul- monata, I. Nova Guinea, n.s. 10 (26): 1-74; 1 map; 62 figs.; plts. 1, 2 Vol. 12; No. 3. THE VELIGER Page 265 Reproductive Cycle of the Coot Clam, Mulinia lateralis (Say), in Long Island Sound *? BY ANTHONY CALABRESE Bureau of Commercial Fisheries, Biological Laboratory, Milford, Connecticut 06460 (Plates 37, 38; 1 Text figure) INTRODUCTION THE cooT cLAM, Mulinia lateralis (Say, 1822), a member of the family Mactridae, has received very little attention in spite of its abundance in favorable environments. This ecologically significant clam is a food of many bottom- dwelling and bottom-feeding animals, including black drum, Pogonias cromis (BREUER, 1957); scup, Stenotomus chrysops, other fishes (VERRILL, 1873) ; starfish, Asterias forbesi (Drsor, 1848), oyster drills, Eupleura caudata and Urosalpinx cinerea (Say, 1822) (C. L. MacKenzie, Jr., personal communication) ; and the greater scaup duck, Aythya marila, and lesser scaup duck, Aythya affinis (Cronan, 1957). Periodic histological examination of gonad tissues during several successive years has been valuable for determining the periodicity of gametogenesis in many marine inverte- brates (Grese, 1959). The reproductive cycle of many species of pelecypods has been described, but until Ropes (1968a) discussed the reproductive cycle of the surf clam, Spisula solidissima, gametogenesis had not been described for any of the Mactridae. The spawning season for Mulinia lateralis, as indicated by the presence of larvae in plankton samples, has been reported to be from mid-July to early September at Prince Edward Island, Canada (Sutuivan, 1948). Loosanorr, Davis & CHANLEy (1966) reported these larvae to be extremely numerous in plankton samples from Long Is- land Sound during late summer, but they did not attempt to define the spawning season. SHaw (1965) determined ' Part of a dissertation submitted to the Graduate Faculty of the University of Connecticut in partial fulfillment of the require- ments for the degree of Doctor of Philosophy. 2 Contribution No. 58 from the Marine Research Laboratory, University of Connecticut. from collections with Thorson bottles that M. lateralis spawns and sets in the Tred Avon River, Maryland, from May to November; peak setting is in September (Hanks, 1968). Knowledge of the reproductive cycle of this clam is essential to an understanding of larval production and, ultimately, to the abundance of this ecologically impor- tant bivalve. The duration of the spawning season of Mu- linia lateralis and the time of appearance of the larvae were determined by following gametogenic development in histological sections throughout the year and by making plankton studies during the spawning season. MATERIALS ann METHODS Mulinia lateralis were collected from several areas in the Bridgeport-Milford-New Haven, Connecticut, area of Long Island Sound. They were kept in boxes of sand placed on an underwater dock in Milford Harbor or in outdoor running water tanks at the laboratory and main- tained as specimens to be sacrificed for histological study. Ten clams were collected from this supply either weekly or in alternate weeks from August 2, 1965 to August 28, 1967, and placed in Lillie’s decalcifier fixative (HuMa- son, 1962) for 24 to 48 hours. The gonad was dissected out, dehydrated in alcohol, cleared in xylene, and embed- ded in paraffin by standard techniques. Gonad tissues were sectioned at 74 with a rotary microtome, stained with Delafield’s hematoxylin, and counterstained with eosin. The sections were examined under an AO Spencer light microscope at X 100 and Xx 430 magnification; the go- nad tissue was assigned to one of the stages of development described by Ropes & STICKNEY (1965), who categorized the seasonal cycle of gametogenesis in the soft-shell clam, Mya arenaria LINNAEUS, 1758, as follows: inactive, ac- Page 266 tive, ripe, partially spawned, and spent. Photomicrographs of the various stages of gametogenesis were taken by use of a standard Zeiss light microscope and camera at X 200 and < 500 magnification. To provide corroborative evidence on the beginning and duration of the spawning season of Mulinia lateralis, plank- ton samples were collected twice weekly at 5 stations in the Bridgeport-Milford-New Haven area from June 17 to October 3 and on October 8 and 24, 1968. By examining the samples I was able to determine when the larvae first appeared and to follow variations in their abundance. Samples were collected with the research vessel, Shang Wheeler, by pumping a 200-gallon water sample through a no. 10 bolting-silk net to screen off the larger, more easily identifiable larvae, and then through a no. 20 net to collect smaller larvae. A 12 2-inch iron suction head was lowered to mid-depth with a 1.5-inch rubber hose to collect samples. The opening of the suction head was covered with fine-mesh copper screening to prevent en- trance of extraneous debris. Two metal drums connected in tandem provided a system whereby water flowing through the first net was trapped in the first drum and passed through the second net through an overflow pipe. The samples were washed into 150-ml jars containing 1 ml of formalin as a preservative and later examined mi- croscopically for the presence of M. lateralis larvae. HISTOLOGICAL STUDY oF GAMETOGENESIS The gonad in ripe Mulinia lateralis is a large and clearly defined organ and easily distinguishes ripe individuals from those with undeveloped gonads or those that have discharged all or most of their gametes. The gonad of ripe animals is an almost uniform, continuous mass of tis- sue surrounding the digestive tract and the digestive di- verticula. During the spawning period the thickness of the gonad decreases as a result of the discharge of gametes. The gonad of spent animals is scarcely discernible by visual examination, but can be observed readily in histological sections. The data from two years of monthly sampling for histological study were combined since progress of game- togenesis was essentially the same both years (Text figure THE VELIGER Vol. 12; No. 3 Inactive Gametogenesis Ei Active Gametogenesis Partially Spawned BH Ripe [_] Spent Ea a se Jan Feb Mar Apr May Jun Jul Aug Sep Oct Nov Dec Month Figure 1 Gonad condition of Mulinia lateralis in Long Island Sound from August 1965 to August 1967. The length of each shaded area represents the percentage frequency of clams in each category. The numbers above each bar represent the total number of clams sampled that month. Data from the two years of observation are combined. 1). Histological examination of these samples indicates that spawning of Mulinia lateralis is completed by the end of September or early in October. No ripe unspawned indi- viduals were found in October; 39.5% were partially spawned and 36.8% were completely spent. The gonads of spent clams examined microscopically during this pe- riod showed large, distended follicles containing few or no spermatozoa or ova within the lumina (Plate 37, Figure 5; Plate 38, Figure 11), whereas the follicles of partially spawned animals contained small numbers of ripe gametes (Plate 37, Figures 3, 4; Plate 38, Figure 10). Sections of gonads fixed in late July and August re- vealed that several animals were beginning to undergo active gametogenesis. Whether this was preliminary to a second annual spawning was not determined. The gonad follicles at this time contained many spermatogenic and oogenic cells in various stages of development (Plate 37, Figure 1; Plate 38, Figure 7). The percentage of clams showing gametogenesis increased through November even though the water temperature decreased to 6° C, and by December about 80% of the animals examined: were un- dergoing gametogenesis (Text figure 1). This activity con- tinued at an increased level through January, February, Explanation of Plate 37 Section of Gonad Tissue of Male Mulinia lateralis Figure 1: Active phase of spermatogenesis. Figure 2: Fully mature. (XX 500) Figure 3: Partially spawned. (XX 200) (X 500) Figure 4: Partially spawned. (XX 500) Figure 5: Spent, with few sperm retained. Figure 6: Inactive phase. (XX 500) (X 200) Tue VELIcER, Vol. 12, No. 3 [CALABRESE] Plate 37 Wa : pee ; ait re « steed ! : « Figure 3 Vol. 12; No. 3 and March, and by April the gametes in 1 of 38 animals sectioned were morphologically ripe. Experiments with Mulinia lateralis made it evident that at least some gametes of this species were both morpho- logically and physiologically ripe at times other than during the normal spawning period. LoosanorF (1937) reported the possibility that the hard-shell clam, Merce- naria mercenaria (LINNAEUS, 1758), contained physio- logically and morphologically ripe gametes at times other than during the immediate prespawning or spawning pe- riod. In one experiment with Mulinia lateralis, animals that were collected on January 10 at a water temperature of -0.1° C were brought into the laboratory and both males and females were induced to spawn immediately when placed in water of 20° C. The eggs released were fertilizable, but larval development was poor. In another experiment, animals collected on January 23 at a water temperature of 4° C were immediately induced to spawn in the laboratory. They released eggs that developed into normal straight-hinge larvae within 24 hours after fertil- ization. By mid-April the water temperature in the outdoor tanks increased to about 7° C; gametogenic activity also increased and one ripe female was found. As stated pre- viously, however, some animals had follicles with at least a few morphologically ripe gametes throughout the win- ter. As the water temperature increased to about 10°C in mid-May, vigorous gametogenesis was resumed and 38.3% of the adult animals examined were ripe. This rapid proliferation and maturation of sex cells continued through June and July. Follicles of ripe males were crowded with spermatozoa whose tails filled the center of the lumina (Plate 37, Figure 2). Each follicle of ripe females contained many mature ova which appeared to be free in the lumen or attached to the follicle walls by slender stalks (Plate 38, Figures 8, 9). The first partially spawned individuals were in samples taken July 10 to 12, when the water temperature had reached approximately 20° C (Text figure 1). By the end of August 61.3% of the animals examined were partially spawned and a few were spent. Slight gametogenic activi- ty began again in late July and August, followed by rapid proliferation of sex cells in September. More ripe clams were found in September than in August, but it was not determined whether this gametogenic activity produced a second wave of spawning. During the colder months, from October through April, a few individuals appeared to be in the inactive stage (Plate 37, Figure 6; Plate 38, Figure 12). At this stage it was most difficult to distinguish between the sexes. The presence of one or two ova or spermatozoa in some follicles, however, enabled me to sex _ the animals. THE VELIGER Page 267 Of a total of 597 Mulinia lateralis examined, 302 (50.6 per cent) were females and 295 (49.4 per cent) were males. No hermaphrodites were found. Hermaphroditism is rare in the closely related surf clam, Spisula solidissima, and then is apparently a developmental accident (RopEs, 1966, 1968b). PLANKTON STUDIES It was possible to study the occurrence of Mulinia lateralis larvae in the plankton only during the summer of 1968 when about 350 samples were collected and examined. Larvae first appeared in the plankton on July 8, when the water temperature ranged from 16° to 20° C at the vari- ous stations sampled. Since it was impossible to identify positively all bivalve larvae in a sample, exact numbers of M. lateralis larvae were not recorded. However, 2000 to 3000 M. lateralis larvae per 200-gallon sample were con- sidered abundant and 10 to 20 larvae considered few.’ Larvae were abundant on July 23 at water temperatures of 19° to 21° C. Numbers were reduced drastically by July 29 and no larvae were found in samples collected August 1 to 8. Larvae were again present on August 12 and were abundant in samples of August 19 to 22. The number of larvae decreased again in late August and by September 3 only a few were in the plankton samples. Numbers con- tinued to be low through October 8, but even on October 24 (when the last samples were collected) the samples contained a few larvae. Water temperature by this time had decreased to about 17° C. MODE or REPRODUCTION AND PELAGIC EXISTENCE The examination of gonad sections suggests several gen- eralizations about the reproductive cycle of Mulinia la- teralis. Gametogenesis is essentially continuous throughout the year, i.e., there is no completely inactive period in winter or summer. Some individuals at each sampling pe- riod showed gametogenic activity, but gametogenesis was most active and more ripe gametes were present from mid- July through August. A spawning peak was reached in August and development of ripe cells again increased in September. It was not determined whether this September development indicates a second reproductive cycle because gametogenesis does not totally cease before this period. The abundance of larvae in plankton samples disclosed that two peaks of spawning occur; one is in late July, just after spawning begins (as determined from histological sections), and the second and greater one is in middle to Page 268 THE VELIGER Vol. 12; No. 3 late August, which coincides with the increased percent- age of partially spawned animals in my histological prep- arations (Text figure 1). This second peak of spawning appears to be the major one for the normal reproductive period, as noted by LoosanorF et al. (1966), who stated that Mulinia lateralis larvae were extremely numerous in plankton samples from Long Island Sound during the lat- ter part of the summer. Sutuvan (1948) found M. lateralis larvae from mid-July to September in plankton samples from Malpeque Bay, Prince Edward Island, Can- ada, a period comparable to that in the present study. Even though Malpeque Bay and Long Island Sound are widely separated geographically, their temperature re- gimes are similar. SULLIVAN first observed M. lateralis larvae in plankton samples about July 18, when the water temperature was about 21° C, and continued to take lar- vae until early September, after which time the water temperature had decreased to about 17°C. These dates and temperatures correspond closely with the data of the present study. This similarity tends to indicate that these two populations of M. lateralis, even though widely sep- arated geographically, are physiologically similar. The temperature requirements for gonad development and spawning of both groups appear to be the same. SHaw (1965) collected recently set Mulinia lateralis | larvae in modified Thorson bottle collectors in the Tred Avon River, Maryland, from May into November and re- ported that this clam appeared to have a continuous peri- od of setting with no apparent gaps during the spawning season. Although he did not report temperature data for this period, I determined from other sources that water temperatures in the Tred Avon River from May to No- vember approximated those in Long Island Sound from July to September. It appears, therefore, that M. lateralis from Long Island Sound and the Tred Avon River, Mary- land, may have similar temperature requirements for gonad development and spawning. Ropes & STICKNEY (1965) reviewed the information available on the reproductive cycle of Mya arenaria and indicated that two important phenomena occurred in this species: “(1) the tendency for these clams to develop gametes and spawn progressively earlier in the season northward and southward from northern Massachusetts, and (2) the bimodal nature of spawning south of Cape Cod.” They further indicated that the bimodality may not have resulted from two distinct reproductive cycles, but rather from an interruption in the spawning during a single cycle. Bimodality of spawning appears to occur with Mulinia lateralis also. Another possible reason for the appearance of high numbers of Mulinia lateralis lar- vae in late summer may be that some of the larvae which had set during the earlier peak had become sexually mature and spawned during the summer. I noted several times during this study that under laboratory or natural conditions little time was required for a new generation of M. lateralis to develop gametes. Under natural conditions I determined that these clams develop gametes within 6 weeks after setting. Some animals found in outdoor tanks in late August, which had entered the tanks as free- swimming larvae in early July and then metamorphosed, had grown to sexual maturity. These specimens appeared to be ripe and I was able to spawn them in the laboratory. They may also have been capable of spawning under natural conditions. The possibility, however, that populations of Mulinia lateralis from different areas belong to different physio- logical races is not excluded. NELson (1928a,. 1928b) was of the opinion that populations of American oysters, Crassostrea virginica (GMELIN, 1791), which inhabit the Atlantic Coast and the Gulf of Mexico were composed of individuals of the same physiological race, or variety, showing the same physiological requirements, such as the minimum temperature at which they could begin spawn- ing. Later studies by Coz (1934), LoosaANorF & ENGLE (1942), LoosanorF & Tomm_rs (1948), SrauBER (1950), and LoosanorF & NoMEjko (1951) suggested the existence of physiologically different groups within the general popu- lation of American oysters. LoosaNorF (1969) studied the gametogenesis of different groups of American oysters from Long Island Sound, New Jersey, Virginia, South Carolina, and Florida by keeping them in Milford Har- bor, Connecticut, for about 3 months and then subjecting them to a long conditioning period at temperatures of 12°, 15°, or 18°C. The sharp differences in the rate of development of their gonads caused him to conclude that there are physiologically distinct populations of oys- ters that require different temperature regimes for com- pletion of gametogenesis and spawning. Explanation of Plate 38 Section of Gonad Tissue of Female Mulinia lateralis Figure 7: Active phase of oogenesis. Figure 8: Fully mature. (XX 200) Figure 9: Fully mature. - (X 500) (X 500) Figure 10: Partially spawned. (XX 200) Figure 11: Spent, with few ova retained. Figure 12: Inactive phase. (XX 200) (X 200) THE VELIcGER, Vol. 12, No. 3 [CALABRESE] Plate 38 2 iPS O WI OYY YA Be ONY ae A aT fees © OD OOO OOF ig ee ade 0.0.9.0, "8 UE OF O07, 2s ities a Ong 9.998 0, 08 6 can Oa7l Lovke af BO 6 a9 cys ar 9 4 4 # on Sg oe # Lt w * O9 ‘ 6% 0° ve 4 9 of = ;: PO. “a vad 4 wy “99 %. tg Loge ¢ 5 y Dns p . : af0”.0,.04 OW Pe Co : a } a Fa ar 4 Ps 4 vey Z. ps x Se we Y ‘ 4% ile. 4 % a Pie. % é ¥ ae 5 t 4 { $3 <3 a ad fe ¢ &: «\e ts Z “* Sy i } ‘ 2m g a a ‘. Bit oe ee * 2s, z “— 5 Figure 9 Figure 12 ie oie —s Vol. 12; No. 3 SUMMARY 1. Gametogenesis of Mulinia lateralis proceeded through- out the year; the rate was low during October and Novem- ber, immediately after spawning had occurred, and then increased rapidly in December. 2. Of a total of 597 clams examined histologically, 302 (50.6% ) were females and 295 (49.4%) were males. No hermaphrodites were found. 3. It was determined from histological sections that spawning began in early July, when the water tempera- ture increased to approximately 20° C, and continued into September. 4, Larvae first appeared in plankton samples in early July at water temperatures of 16° to 20° C and continued to be in the plankton from early July to late October. Peak abundance was in middle to late August, which co- incided with the period when histological samples showed greatest abundance of mature gametes. 5. It is probable that more than one generation of Mulinia lateralis is produced in a single year. ACKNOWLEDGMENTS I thank the following members of the Milford laboratory for their assistance: Dr. James E. Hanks and Mr. Harry C. Davis for their many helpful suggestions throughout this study and for their constructive criticism of this manu- script; Mr. Manton L. Botsford for assistance in preparing the photographs; and Miss Rita S. Riccio for her editorial review. LITERATURE CITED BREUER, JOSEPH P. 1957. An ecological survey of Baffin and Alazan Bays, Texas. Publ. Inst. Mar. Sci. Univ. Texas 4 (2): 134-155 (June ’57) Cor, WesLEY RoswELL 1934. Alternation of sexuality in oysters. Amer. Natur. 68 (176): 236 - 251 Cronan, JoHN M., Jr. 1957. | Food and feeding habits of the scaups in Connecticut waters. The Auk 74: 459 - 468 GiesE, ARTHUR CHARLES 1959. Comparative physiology: annual reproductive cycles of marine invertebrates. In: Ann. Rev. Physiol. 21: 547 - 576. V. E. Hall, ed. Ann. Rev., Inc., Palo Alto, Calif. Hanxs, Rosert WILLIAM 1968. Benthic community formation in a “new” marine en- vironment. Chesapeake Sci. 9 (3): 163-172 (Sept. 68) THE VELIGER Page 269 Humason, GretcHen L. 1962. Animal tissue techniques. San Francisco. 468 pp. Loosanorr, Victor LYon 1937. | Development of the primary gonad and sexual phases in Venus mercenaria LINNAEUS. Biol. Bull. (Woods Hole) 72 (3): 389-405 (June 1937) 1969. Maturation of gonads of oysters, Crassostrea virginica, of different geographical areas subjected to relatively low tem- peratures. The Veliger 11 (3): 153 - 163; plts. 19 - 25 (1 January 1969) Loosanorr, Victor Lyon « James B. ENGLE 1942. Accumulation and discharge of spawn by oysters living at different depths. Biol. Bull. (Woods Hole) 82 (3): 413 - 422 (June 1942) LoosanorF, Victor Lyon & CHartes A. NomEj]Ko 1951. Existence of physiologically-different races of oysters, Crassostrea virginica. Biol. Bull. (Woods Hole) 101 (2): 151-156; 2 text figs.; 1 table (October 1951) LoosanorF, Victor L. « FRANCES D. ToMMERS 1948. Effect of suspended silt and other substances on rate of feeding of oysters. Science 107: 69 - 70 (16 Jan. ’48) Loosanorr, Victor Lyon, Harry Caru Davis & PAuL E. CHANLEY 1966. Dimensions and shapes of larvae of some marine bivalve mollusks. Malacologia 4 (2): 351 - 435; 61 text figs. Netson, THURLOW CHRISTIAN 1928a. On the distribution of critical temperatures for spawn- ing and for ciliary activity in bivalve molluscs. Science 67: 220 - 221 1928b. Relation of spawning of the oyster to temperature. Ecology 9: 145 - 154 Ropes, Joun W. 1966. | Hermaphroditism in the surf clam, Spisula solidissima. Ann. Reprt. Amer. Malacol. Union, p. 26 1968a. Reproductive cycle of the surf clam, Spisula solidissima, in offshore New Jersey. Biol. Bull. (Woods Hole) 135 (2) : 349 - 365 (October 1968) 1968b. Hermaphroditism in the surf clam, Spisula solidissima. Proc. Nat. Shellfish. Assoc. 58: 63 - 65 (June 1968) Ropes, JoHN W. & ALDEN P. STICKNEY 1965. Reproductive cycle of Mya arenaria in New England. Biol. Bull. (Woods Hole) 128 (2): 315 - 327 (April 1965) SHaw, WILLIAM N. 1965. Seasonal setting patterns of five species of bivalves in Tred Avon River, Maryland. Chesapeake Sci. 6 (1) : 33-37 (March 1965) W.H. Freeman and Co., StauBer, LESLrE A. 1950. The problem of physiological species with special ref- erence to oysters and oyster drills. | Ecology 31(1): 109-118 2 text figs.; 1 table (January 1950) SuLLivaN, CHarLotTEe M. 1948. _ Bivalve larvae of Malpeque Bay, PE. I. Res. Brd. Canada 77: 1 - 36 VERRILL, Appison E. 1873. | Report upon the invertebrate animals of Vineyard Sound and the adjacent waters, with an account of the physical characteristics of the region. Reprt. U.S. Fish Comm. on the condition of the sea fisheries of the South Coast of New England in 1871 and 1872: 295 - 747 Bull. Fish. Page 270 THE VELIGER Vol. 12; No. 3 Three New Species of Muricacean Gastropods from the Eastern Pacific WILLIAM K. EMERSON Department of Living Invertebrates, American Museum of Natural History Seventy-ninth Street and Central Park West, New York, New York 10024 AND ANTHONY D’ATTILIO Natural History Museum, San Diego, California 92112 (Plates 39, 40; 4 Text figures) AS A RESULT OF OUR LONG-TERM investigation of the west . American Muricacea, three new species, two referable to the Muricidae and one to the Coralliophilidae, recently came to our attention. We are indebted to Mr. and Mrs. André DeRoy of Santa Cruz Island, Galapagos Islands and Dr. James H. McLean of the Los Angeles County Museum of Natural History for making this material available for study. Dr. George E. Radwin of the Natural History Museum of San Diego, California and Professor Masao Azuma of Nishinomiya, Japan kindly provided data on the radulae. MoriciDAE Murexiella radwini EMERSON & D’ATTILIO, spec. nov. (Plate 39, Figures 1, 2; Text figure 2) Description: The holotypic shell is 33.5 mm in length, with 7 convex postnuclear whorls; 24 unsculptured nuc- lear whorls are preserved on the smallest of the two im- mature paratypes. The surface of the shell is richly imbri- cated, especially on the projecting spines; and it is colored a warm fleshy violet. The aperture is moderately small, ovate; the columellar edge is slightly erect below, and the outer lip is strongly crenulated by the exterior spiral sculpture. The axial sculpture consists of 5 varices which are obliquely descending to the right. Six spiral cords are present on the body whorl. The upper 3 are recurved; the lower 3 extend outwardly but are not recurved. There are 2 cords on the spire, which are spinose at the varices. The major spiral cords are composed of 1 major ridge and 2 to 3 minor continuous ridges on each side; their surfaces are overlaid by a continuous pattern of numerous tile-like flattened lamellae; at the outer edges of the ridges the lamellae develop into strong laterally projecting scales. In the area between the last two varices the spiral sculp- ture is much diminished. On the lower varices approaching the spiny extensions of the spiral cords, there are abrupt deep channels which strongly separate the major varical spines. On their apertural side the spines are open; be- tween the spines, except for their distal projections, there are numerous, undulating, erect, blade-like lamellae. ‘The narrowly opened siphonal canal is obliquely oriented to the left, is flattened for most of its length, and recurved only distally. The canal is ornamented on the right by 2 long spines and on the left by the ends of the previous siphonal canals; on the remaining area of the canal, there are present only growth striae. p The aperture within is colored lightly but richly violet. Exteriorly the shell is colored a fleshy violet except for the varices which are a pinkish tan. No periostracum is apparent. The operculum is muri- coid, with a basal nucleus. The radular dentition of the new species is illustrated (Text figure 2), and we are also illustrating (Text figure 1) the radular dentition of Mu- Vol. 12; No. 3 Figure 1 Murexiella hidalgoi (CrossE, 1869) Central tooth and a lateral tooth, “Blake” Station 272, off Barbados (U.S. N. M. No. 87081) ; greatly enlarged rexiella hidalgoi (Crosse, 1869; U.S. N. M. no. 87081), the type of the genus Murexiella CLENCH & FARFANTE, 1945. The radular slides of both species were kindly pre- pared by Dr. George E. Radwin, Curator, San Diego Natural History Museum. Types: The holotype (A. M.N.H.no. 155903), which measures 33.5 mm in length, was dredged by André and Jacqueline DeRoy in 100m at Tagus Cove, Isabella Is- land, Galapagos Islands, on January 29, 1968 (type local- Figure 2 Murexiella radwint EMERSON & D’ATTILIO, spec. nov. Central tooth and a lateral tooth from paratype (S. D. N. H. S. No. 51335); greatly enlarged ity). In addition, the following paratypic material was studied: One immature specimen, height 16.8 mm (S. D. N. H.S. no. 51335), from which the radula was extract- ed; and a smaller immature specimen, height 13.5 mm (A. D’Attilio collection). Both paratypes were dredged from the same locality and on the same date as the holo- type. Remarks: This distinctive species is as yet known only from the material at hand. It is related most closely to Murexiella hidalgoi: (Crosse, 1869), of the western At- THE VELIGER Page 271 lantic. Crosse’s species has a narrower shell with longer spines. Murexiella diomedaea (Dax, 1908), from the eastern Pacific, has a slender, more spinose shell. Large specimens of Murexiella humilis (Broperip, 1833), es- pecially those found in the Bay of Panama, have a more rebust, heavier shell and differ also in the short, blunt, more recurved spines, and in other sculptural details. “Murex” galapaganus EMERSON & J)’ATTILIO, spec. nov. (Plate 39, Figures 3 to 6; Text figures 3, 4) Description: Shell is dull white, of moderate size (at- taining 46+ mm in length). Whorls are 7, the early ones somewhat obscure through erosion, with 6 varices ornamented with long recurved spines. The whorls are subangulate, and, on the extended spire, there are 2 eee A ravi b Figure 3 Figure 4 Figures 3 and 4 “Murex” galapaganus EMERSON & D’ATTILIO, spec. nov. Figure 3: Central tooth and lateral tooth from a paratype (A. D’Attilio coll.) ; X 300 (drawing courtesy of Prof. Azuma) Figure 4: Operculum, outer and inner side; greatly enlarged Page 272 spiral cords, one on the shoulder and one above the im- pressed suture. On the body whorl there is a low rounded spiral cord on the shoulder, 2 low spiral cords appear below, and one additional, much weaker cord is just above the canal. The spines occur as extensions of the spiral cords at each axial varix. The axial varices extend over the shoulder diagonally as rounded, cord-like structures and are depressed midway, rising at their junction with the next whorl. The aperture is ovate, of moderate size and polished white; the edge of the apertural lip is ele- vated from the labial varix by a trough; the parietal lip is not free in the holotype due to immaturity. The largest, paratypic specimen (Plate 39, Figures 5, 6) has the pari- etal lip mostly erect and has 8 poorly developed apertural denticles on the outer lip. One immature paratype (A. M.N.H.no. 155907) possesses 24 smooth, nuclear whorls. Although not preserved on the holotype, possibly due to erosion, a thin outer layer of chalky matter occurs on the paratypes. This chalky material, which is microscop- ically striate, overlies the harder calcite surface. The operculum has a terminal nucleus, situated sub- laterally (Text figure 4). The radula is illustrated in Text figure 3. Types: Holotype (A. M.N.H.no. 155906), dredged in 150m, South Academy Bay, Santa Cruz Island, Gala- pagos Islands, June 11, 1968, collected by the DeRoys. Two paratypes (one in the DeRoy collection, length 43 mm; one in the D’Attilio collection, length 46mm) from the same depth and locality, collected by the DeRoys, June 10, 1968 (type locality). Other paratypic material: One immature specimen, A. M.N. H. no. 155907, dredged in 200 m, North Santa Cruz Island, collected by the DeRoys, December 9, 1968, 11.5 mm in length. One immature specimen, Los Angeles County Museum, Allan Hancock no. 816-38, north of Hood Island, Galapagos Islands, 15 mm in length. Remarks: On the basis of our present knowledge, we can not assign with certainty this distinctive new species to an existing genus. In shell morphology, it is similar to the THE VELIGER Vol. 12; No. 3 type species of Bathymurex CLENCH & TURNER, 1945, and Paziella JoussEAUME, 1880, the radular characters of which are not known. On the other hand, the radular dentition of the type species of Takia Kuropa, 1953 (p. 190; fig. 10 on p. 180) is morphologically close to that of the new species, but these taxa differ greatly in shell morphology, especially in the lack of spines on the shells of Takia. Both, however, have a chalky outer surface. Two species described from Japanese waters, ““Boreotrophon” gorgon Dau, 1913 and “B.” echinus Dati, 1918 have similar opercula and radulae (Azuma, in litt.), but the shells lack well-produced spines and an outer chalky layer. Dall’s taxa were placed in Trophonopsis Bucguoy, DauT- ZENBERG & DoLLFus, 1882, by Kuropa & HaBe (1952), and were assigned to Bathymurex as a subgenus of Tro- phonopsis by AzumMA (1960). These species were subse- quently assigned to Paziella, with Bathymurex as a syno- nym, by Voxes (1964). Thus, the new species could be placed in the Trophoninae, Muricinae, or with the aspella- like forms near Takia, depending on the generic assign- ment one would choose to select for it. Although the Gala- pagan specimens have a “trophonoid” appearance, we hesitate to place the new species generically until we have a better understanding of the taxonomic placement of these generic taxa. If the new species were to be referred to an existing genus on the basis of shell characters, Paziella would appear to be the most promising assign- ment. CoRALLIOPHILIDAE Latiaxis (Babelomurex) santacruzensis EMERSON & D’ATTILIO, spec. nov. (Plate 40, Figures 1 to 4) Description: Shell of medium size, light in structure; pale, ochre colored on its dorsum, aperture rosy pink: Nucleus in the holotype is lacking and the first and per- haps second whorl, in addition, are eroded. There follow 5 strongly carinated whorls each bearing on the carina Explanation of Plate 39 Figures 1 and 2: Murexiella radwint EMERSON & D’ATTILIO, new species, holotype; X 2 Figures 3 to 6: “Murex” galapaganus EMERSON & D’ATTILIO § g £4 > new species Figures 3, 4: Holotype (A. M. N. H. No. 155906); 2 Figures 5,6: Paratype (D’Attilio collection) from type locality; X 2 THE VELIGER, Vol. 12, No. 3 [Emerson & D’Arrtizio] Plate 39 Figure 1 i t H i Figure 4 Figure 5 Figure 6 Vol. 12; No. 3 THE VELIGER Page 273 extended, upturned, narrowly triangular spines; there are 10 of these long spines, some of which have been broken off the shoulder carina; the number of spines per whorl increases on each succeeding whorl. The whorls are deeply parted at the suture, added to which the spiny peripheral keel sharply emphasizes the angulated character of the spire. Spiral sculpture is further evident in the presence of weak threads on the spire which are axially overlaid by poorly developed scabrous lamellae. This spiral sculpture is present also on the convex surface of the body whorl above the shoulder to about midway on the slightly swollen body whorl. At the periphery of the body whorl (but in an apertural view, at the junction of outer lip and aperture), there are about 10 stronger spiral cords intercalated with weaker cords extending anteriorly. Scab- rous ornamentation overlies the spiral sculpture. Except for 2 or 3 strong axial plicae nearer the outer lip, there are only weak axial undulations on the body whorl. The aperture is comparatively large, ovate, somewhat angled at the juncture with the body; the lip is thin, crenulated by reason of the exterior sculpture; a pro- nounced groove is formed by the hollow edge of the spiral keel. A small portion of the inner lip is adherent above but erect below. The canal is strongly recurved with a coarsely sculptured siphonal fasciole formed by the presence of 5 previous, preserved canals; a narrow but deep umbilical chink is present. Types: The holotype (A. M.N.H.no. 155901) is an adult, 33.8 mm in length, greatest width 33.5 mm includ- ing spines, dredged alive by the DeRoys, in 150 m, south of Academy Bay, Santa Cruz Island, Galapagos Islands, May 29, 1968 (type locality). Paratypes: Anthony D’Attilio collection, one adult speci- men; one immature specimen, 7.8 mm in length, A. M. N. H. no. 155902; one immature specimen; all dredged with the holotype. Jacqueline DeRoy collection, 1 mature spe- cimen, 28 mm in length, dredged with the holotype (Plate 40, Figures 3, 4). One immature specimen, Los Angeles County Museum, Allan Hancock no. 810-38, off Barring- ton Island, Galapagos Islands, in 134 m. Remarks: An unfigured paratype, no. 155902, A. M.N. H. collection, retains the nucleus and protoconch in a well-preserved condition. In this specimen there are 14 smooth nepionic whorls followed by 34 post-nepionic whorls which have numerous erect lamellae. Each whorl has a strong spiral shoulder ridge, above which the whorl is slightly and convexly sloping toward the suture; it is sculptured with the above mentioned blade-like lamel- lae; below the shoulder ridge there is a second ridge close to the suture; the area between the two ridges is convex; the lamellae in this area continue from above but are diagonally placed with respect to those above the shoulder. There are present in the eastern Pacific a few represent- atives of this genus. Only one of these, Latiaxis oldroydi (Oxproyp, 1929) is of comparable size. Latiaxis oldroydi is known to occur off southern California. The shell is more robust, is white throughout, with coarser sculpture; its spire is higher and with a narrower peripheral spiny keel. Of more common occurrence in the Galapagos Is- lands is Latiaxis hinds (CarPENTER, 1857) (= Tro- phon muricatus Hinps, 1843). This species is collected in shallow water and it has a shell of smaller size. Compari- son may be made with one other species, Latiaxis dalli EMERSON & D’Arttiio, 1963, from the western Atlantic. Latiaxis dalli is nearest to L. santacruzensis, spec. nov., in general form and size, differing in being entirely white and in having well-developed, evenly dispersed spiral cords over the entire shell. LITERATURE CITED Azuma, Masao 1960. A catalogue of the shell-bearing Mollusca of Okinoshimna, Kashiwajima and the adjacent area (Tosa province) Shikoku, Osaka, Japan. pp. 1-102; 1-17; plts.1-5 (20 March) BropDERIP, WILLIAM JOHN 1833. | Characters of new species of Mollusca and Conchifera collected by Mr. Cuming. Proc. Zool. Soc. London for 1832 (prt. 2): 173-179 (14 January 1833) Bucguoy, E., PH. DauTzENBERG & G. F DotiFus 1882. | Les mollusques du Roussillon. Paris, vol. 1, fasc. 1: 1-40; plts. 1-6 CarPENTER, PHILIP PEARSALL 1857. | Report on the present state of our knowledge with regard to the Mollusca of the west coast of North America. Rep. Brit. Assoc. Adv. Sci. for 1856: 159 - 368; plts. 6-9 CiencH, WituiaM James « I. Pérez FaRFANTE 1945. The genus Murex in the western Atlantic. Johnsonia 1 (17): 1-58; plts. 1-29 (29 May 1945) Crosse, H. 1869. Diagnoses molluscorum novorum. Paris, ser. 3, 9 (17) : 408 - 410 Dati, WILLIAM HEALEY 1908. Reports on the dredging operations off the west coast of Central America to the Galapagos, to the west coast of Mexico, and in the Gulf of California XIV. The Mollusca and Brachiopoda. Bull. Mus. Comp. Zool., Har- vard; 43 (6): 205 - 487; plts. 1-22 (October 1908) 1913. | Diagnoses of new shells from the Pacific Ocean. Proc. U.S. Nat. Mus. 45 (2002) : 587 - 597 (11 June 1913) 1918. Notes on Chrysodomus and other mollusks from the North Pacific Ocean. Proc. U.S. Nat. Mus. 54 (2234): 207 - 234 (5 April 1918) Journ. Conchy]l. Page 274 THE VELIGER Vol. 12; No. 3 Emerson, WILLIAM KeitH & ANTHONY D’ATTILIO 1963. A new species of Latiaxis from the western Atlantic. Amer. Mus. Novitates no. 2149: 1 - 9; 6 text figs. (25 July 1963) JoussEAuME, FELIx PIERRE 1880. Division méthodique de la famille des purpuridés. Le Naturaliste 2 (42) : 335 - 336 Kuropa, TOKUBEI 1953. On the Japanese species of “Trophon.” (4): 186 - 202; text figs. 1-8 Venus 17 Kuropa, ToKuBEI & TADASHIGE HABE 1952. Checklist and bibliography of the Recent marine Mol- lusca of. Japan. 210 pp.; 2 maps. Tokyo, Japan (4 April 1952) Otproyp, IpaA SHEPARD 1929. Description of a new Coralliophila. 42 (3): 98, 99; plt. 5 Vokes, Emity Hoskins 1964. Supraspecific groups in the subfamilies Muricinae and Tritonaliinae (Gastropoda: Muricidae). Malacologia 2 (1): 1-41; plts. 1-3 (September 1964) The Nautilus (January 1929) Explanation of Plate 40 Latiaxis (Babelomurex) santacruzensis EMERSON & D’ATTILIO, new species Figures 1,2: Holotype (A. M. N. H. No. 155901); X 2 Figures 3,4: Paratype (J. DeRoy collection) , from type locality; X 2 THE VELIGER, Vol. 12, No. 3 [EMERSON & D’ArrTiLio] Plate 40 Figure 1 Figure 2 Figure 3 Vol. 12; No. 3 THE VELIGER Page 275 A New Species of Helminthoglypta from the Mojave Desert WALTER B. MILLER Department of Biological Sciences, University of Arizona, Tucson, Arizona 85721 (Plate 41; 2 Text figures) In 1930, S.S. BERRY DESCRIBED a new species of desert snail from the El Paso Mountains of the northern Mojave desert of California. With only shell characters for dia- gnosis, he named it Micrarionta (Eremarionta) microme- talleus S.S. Berry, 1930. Subsequently he dissected adult specimens and determined that the anatomical characters were those of Sonorella. The shell characters, however, were different from those of other known Sonorella, and in 1943 he established a new subgenus Mohavelix to ac- commodate species of Sonorella with small, thin, subdis- coid, and widely umbilicated shells. Accordingly, M. (E.) micrometalleus became Sonorella (Mohavelix) microme- talleus (BERRY), the type and only species of Mohavelix. Since 1964 I have been intensively studying Sonorella and in 1967 I submitted a revision of the genus to the University of Arizona as my doctoral dissertation. I be- came increasingly convinced that Sonorella (Mohavelix) micrometalleus did not share a close phylogeny with other Sonorella, i. e., they did not evolve from the same immedi- ate pre-Sonorella ancestor, and eventually proposed (Mit- LER, 1968) that Mohavelix should be raised to generic rank. The phylogeny of Mohavelix has remained obscure, however, with the most credible hypothesis being its deri- vation from some ancestral Eremarionta, possibly close to Eremarionta aquaealbae Berry, 1922. While attempting to obtain live specimens of Mohavelix micrometalleus from the arid southern slopes of the El Paso Mountains (the type locality is in the southern part of Last Chance Canyon) in early January 1969, I decided to search for more suitable rockslides on the more humid northern slopes of the range. I was rewarded by finding a gigantic north-facing slide which yielded 95 dead shells and 10 live specimens, of which 3 were adult. They looked in all respects like M. micrometalleus. Jubilant over this new find in a prolific locality, I was totally astonished to find that the anatomy revealed these snails to be a new species of Helminthoglypta, described below. The discov- ery of this population of Helminthoglypta in the El Paso Mountains, with shell and certain anatomical characters remarkably similar to those of M. micrometalleus, has now afforded a more credible hypothesis for the derivation of this species. This hypothesis is also discussed below. Helminthoglypta micrometalleoides W. B. Mitirr, spec. nov. (Plate 41, Figures 1 and 2; Text figure 1) Description of Holotype: Shell very small for the genus, depressed, discoid, thin, light-brown, with a darker brown spiral band on the well-rounded shoulder; widely umbili- cate, the umbilicus contained about 6 times in the diame- ter of the shell. Embryonic shell of about 13 whorls, with faint, microscopic wrinkles. Post-embryonic whorls with minute granular wrinkles and papillae. Body whorl with spirally-descending, long, hyphen-like papillae occasion- ally confluent to form long threads, superimposed over the radial ridges, persisting into the umbilicus; periostra- cum thin, silky-lustrous. The last whorl descends slightly to the scarcely expanded, thin peristome; aperture oblique, relatively large. Shell Measurements: Height 5.6 mm, maximum diame- ter 10.9 mm, umbilicus 1.7 mm. Number of whorls 44. The animal: The animal, when extended, has a dark-grey to black body wall, with scattered white glandular papil- lae. The mantle collar shows a thick mat of white mucus glands, giving the collar an overall whitish appearance; the area around the pneumostome is chalk-white. The mantle above the lung is pigmented with small, black, closely-spaced spots. The Genitalia: The genitalia (Text figure 1) are typical for the genus. The penis is strongly swollen in the middle where the internal tube, detached from the external wall, becomes thickened and forms a papilla which can be likened to a very short verge. Anteriorly, it consists of a hollow, eversible sac. Distally, it merges into the epiphal- Page 276 THE VELIGER Vol. 12; No. 3 lus where the internal tube becomes completely adnate to the external wall. The epiphallus is of uniform diame- ter and is equipped with a moderately long epiphallic caecum at its distal end. The penial retractor muscle originates on the floor of the lung and is inserted on the epiphallus near the penial end. The vagina is short, equal hd ag) 5.0 mm in length to the saccular proximal end of the penis. The free oviduct is longer than the vagina. The long sperma- thecal duct gives rise to a diverticulum about halfway along its length; the diverticulum is about equal in length to that part of the spermathecal duct posterior to their junction. The globular spermatheca is bound by connec- tive tissue to the posterior end of the uterus. The muscu- lar dart sac is small, globular, and situated at the summit of a longer atrial sac; it contains a short, conical dart. The two side-by-side mucus bulbs join proximally into a single duct which enters the atrial sac at its junction with the dart sac; distally, each mucus bulb connects with a thin, glandular, U-shaped duct which passes into a broad, thin membrane enveloping the entire dart apparatus and much of the lower genitalia. Dimensions, in millimeters, of dis- tinctive structures follow: Penis 5.0 mm Epiphallus 7.0 mm Epiphallic caecum 8.0 mm Penial retractor 3.5mm Spermathecal duct 14.5 mm Spermathecal diverticulum 8.5 mm Vagina 2.0 mm Free oviduct 3.0 mm Type Locality: El Paso Mountains, Kern County, Califor- nia, in north-facing, high rockslide of small rocks, between crag outcroppings on south side of Iron Canyon Road, at a point 3 miles up the canyon from the junction of the road with the Garlock-Goler highway (W.B. Miller, 5 January 1969). Disposition of Specimens: Holotype: deposited in the California Academy of Sciences, Geology Type Collection, no. 13169. Figure 1 (<— adjacent column) Helminthoglypta micrometalleoides W. B. MiLuEr, spec. nov. Lower genitalia of holotype; drawing made from projection of stained whole mount. Scale in millimeters > ag albumen gland ats atrial sac da dart dp distal part of penis ds_ dart sac ec epiphallic caecum ep epiphallus fo free oviduct hd hermaphroditic duct itp internal tube of penis mb mucus bulb pp proximal part of penis prm penial retractor muscle prs prostate sp spermatheca spd spermathecal duct spdv spermathecal diverticulum ut uterus va vagina vd vas deferens go genital orifice Tue VELIGER, Vol. 12, No. 3 [MiLiER] Plate 41 Figure 1 Figure 2 esl ne ll Figure 3 Figure 4 Figures 1, 2: Helminthoglypta micrometalleoides W. B. Mier, spec. nov. Holotype. California Academy of Sciences, Geology Type collection no. 13169. El Paso Mountains, Kern County, California. Scale in millimeters Figures 3, 4: Mohavelix micrometalleus (BERRY, 1930). El Paso Mountains, Kern County, California. Scale in millimeters Vol. 12; No. 3 Paratypes: in the Invertebrate Museum, Department of Biological Sciences, University of Arizona, and in the private collection of the author. Remarks: Helminthoglypta micrometalleoides is the smallest species of Helminthoglypta described to date. Examination of approximately 100 paratypes (not all adults) reveals a remarkable constancy of characters. The maximum diameter of the shell varies only from 9.3 mm in the smallest adult to 11.3 mm in the largest. Shell sculp- ture depends on the age of the shell; older shells have worn embryonic whorls and papillae. The umbilical di- ameter varies from as large as to slightly larger than that of the holotype. The genitalia from three dissected speci- mens do not appear to provide diagnostic characters to distinguish this species from other desert helminthoglypts. The peculiarly shaped penis is a characteristic of all known and dissected desert helminthoglypts, as reported by W. O. Gregg (in litt.). Helminthoglypta micrometalleoides appears to be most closely related to H. fishert (BartscuH, 1904) of the Pan- amint Mountains and to H. greggi WILLeTT, 1931, of Soledad Mountain. It can be readily distinguished from these other species by the much smaller shell diameter. The El Paso Mountains are situated geographically be- tween the above localities. In field diagnosis, H. micro- metalleoides can be easily mistaken for Mohavelix micro- metalleus. The size, shape, color, texture, and general ap- pearance of the shell are the same for both species (Plate 41, Figures 3 and 4). Microscopic examination of fresh shells reveals that M/. micrometalleus has an embryonic sculpture of thickly-set, spirally arranged, hyphen-like papillae similar to Eremarionta. The post-embryonic sculpture is more papillose and radially wrinkled than that of H. micrometalleoides and the periostracum is less glossy. The adult genitalia provide the major diagnostic difference between Helminthoglypta and Mohavelix. Mo- havelix (Text figure 2) has simplified genitalia similar to Sonorella. The atrial sac, dart sac mucus glands, and spermathecal diverticulum are all missing, while the epi- phallic caecum is reduced to a vestige; the penis has a short verge at its distal end. It is most interesting to note, however, that the remaining structures, such as penis, epiphallus, spermathecal duct, vagina, free oviduct, and uterus have the same relative dimensions as in H. micro- metalleoides. Concerning the phylogeny of Helminthoglypta micro- metalleordes, it appears most likely that this species evolved from a common ancestor of the desert helminthoglypts. It is debatable that all described species of desert hel- minthoglypts are good biological species, with fully estab- lished reproductive isolation; hybridizing experiments be- THE VELIGER Page 277 hd ag 2 4 : | = 2 Be spd i prs 42: ut Hf = V it Gr ae fo ve NS bf er cc, = pe go 5.0 mm Figure 2 Mohavelix micrometalleus (BERRY, 1930) Lower genitalia; drawing made from projection of stained whole mount. Scale in millimeters ag albumen gland ec epiphallic caecum ep epiphallus fo free oviduct go genital orifice hd hermaphroditic duct pe penis prm penial retractor muscle prs prostate sp spermatheca spd spermathecal duct ut uterus va vagina vd vas deferens ve verge Page 278 tween H. micrometalleoides, H. greggi, and H. fishert would be desirable. The large difference in size of H. micrometalleoides from all other known species of Hel- minthoglypta would suggest reproductive isolation from sheer mechanical incompatibility, even if other physio- logical, genetic, or chromosomal barriers did not exist. What appears to be most interesting and significant, however, is the possible evolutionary relationship of Helminthoglypta micrometalleoides to Mohavelix micro- metalleus. The nearest relative of M. micrometalleus is not known, although, as stated earlier, a descent from an ancestral Eremarionta would be plausible; a possible de- scent from an ancestral Sonorella is too difficult to support. It is now suggested that M. micrometalleus evolved direct- ly from an isolated population of H. micrometalleoides. The close similarities of shell characteristics of H. micro- metalleoides and M. micrometalleus, as well as the simi- larities in relative size and shape of the significant ana- tomical structures common to both species suggest a close relationship. The evolution of the Helminthoglyptidae is replete with instances of secondary simplification of ana- tomical structures, as in the case of Sonorelix, Sonorella, Tryonigens, Micrarionta, Eremarionta, as well as Mohav- elix. The mechanism of this simplification has not been determined. Populations of different genera and species are often in similar ecological niches, sometimes sympatric, THE VELIGER Vol. 12; No. 3 and the adaptive advantages of a simplified reproductive system are not apparent. Genetic drift is the most likely mechanism in desert populations where marginal isolates are periodically and frequently subjected to prolonged drought to the point where individual numbers become critically low. Chromosomal breakage, inversion, reduc- tion, or translocation could account for large losses of structures, which, fortunately, are not fatal. It is hoped that studies of the chromosomes of Hel- minthoglypta micrometalleoides and Mohavelix micro- metalleus can be undertaken in the near future. Also, gross comparison of proteins by chromatography or elect- rophoresis might yield data on the extent of relationship between the two species. The specific name is chosen to indicate the close resem- blance between the two species. LITERATURE CITED BErry, SAMUEL STILLMAN 1930. New helicoid snails from the Mohave Desert. Ann. Mag. Nat. Hist. 10 (6): 187 - 193 1943. | On the generic relationships of certain Californian xero- phile snails. Trans. San Diego Soc. Nat. Hist. 10 (1): 1 - 24 MILLER, WALTER BERNARD 1968. New Sonorella from Arizona. 30 - 63 The Nautilus 82 (2) : Vol. 12; No. 3 THE VELIGER Page 279 Two New Species of the Genus Caldukia Burn & MILLER, 1969 (Mollusca : Gastropoda : Opisthobranchia ) from New Zealand Waters MICHAEL C. MILLER Department of Zoology, University of Auckland, Private Bag, Auckland, New Zealand (21 Text figures) INTRODUCTION THE GENUS Caldukia BURN & MILLER, 1969 was estab- lished to embrace 3 species of janolid nudibranch, one Australian and two from New Zealand, which could not be placed in any of the known genera. Caldukia is distin- guished from the other genera of the family JANOLIDAE (Zephyrina QuaTREFAGES, 1844; Janolus Bercu, 1884; Antiopella Hoye, 1902; a new genus (MILLER, in press) by the shape of the rhinophoral club (short and stout witha small series of primary lamellae, each with regularly dis- posed rows of secondaries), the lack of an inter-rhino- phoral crest, a radula of the formula 6-1-6 with the lateral teeth strongly cuspidate, and very strong unequal jaws with a few large horny teeth. A fairly complete comparison of the genera has already been made (Mar- cus, 1955, 1958; BurN & MILter, 1969; MILter, in press). The Australian species, which is the type of the genus, was first described a little over a decade ago and at that time was provisionally assigned to the genus Proctonotus ALDER & Hancock, 1844 (Burn, 1958) ; although the two New Zealand species were first discovered in 1961, original descriptions of them are only now being presented. ACKNOWLEDGMENTS I wish to thank Professor J. E. Morton for advice and encouragement, Mr Robert Burn for discussing arminid systematics and nomenclature and for letting me examine his colour photograph of a living specimen of Caldukia affinis, Dr E. J. Batham for permitting me to use the Portobello Marine Biological Station and the University Grants Committee (New Zealand) for financing much of my field work. CLASSIFICATION NUDIBRANCHIA Arminacea PACHYGNATHA JANOLIDAE DESCRIPTIONS Caldukia albolineata MitteR, spec. nov. Morphology: Length, extended, 11 mm (only one speci- men collected). Body soft, lanceolate in outline (anterior end blunt) ; low, back slightly arched with a large ellip- tical swelling, the pericardium, in the centre, which is confluent posteriorly with a prominent longitudinal ridge (the dorsal sinus) which runs part way to the anus (Figure 1). Rhinophores one-sixth to one-seventh of the length of the body; peduncle very short; club stout with 6 sloping primary lamellae (lamellae of the two sides of the rhinophore widely separate anteriorly, but approxi- mate posteriorly), each with an upper and lower row of small plates arranged alternately, and the rachis is pro- duced apically as a cylindrical truncate process about one-third of the height of the rhinophore (Figure 2). Oral tentacles are short, blunt triangular lobes. Cerata linear, apices pointed, non-caducous and very mobile (Figure 3) ; the largest, when extended, roughly one-fifth of the length of the body; inserted in 3 staggered longi- tudinal rows, cerata smallest at the edge of the notum, increase in size centripetally (Figure 4). Foot rounded at the front; tail short, tapers to a fine point. Anus at the tip of a large papilla situated in the mid-line near the Page 280 Figure 1 Caldukia albolineata Dorsal view of the living animal posterior end of the notum. Reproductive apertures on the right side, just below the edge of the notum at a level midway between the rhinophores and the front of the peri- cardium. Renal pore on the right side, just below the edge of the notum and at a little distance from the rear end of the pericardium (Figure 4). THE VELIGER Vol. 12; No. 3 Colour: Body translucent, pale dull yellow; hermaphrodite and female accessory glands show through as a central opaque mass. Rhinophores pale dull yellow, apical process covered with opaque white. Each ceras with a dark brown diverticulum, centre of inner surface with a narrow lumpy stripe of opaque white running from the base to the tip, flanked by fairly large spots of the same pigment (Figure 3). Dorsal surface of tail with a wedge-shaped patch of opaque white. Alimentary System: Figure 5. Oral tube short and wide, leads to the massive, ovate (when viewed from above), Figure 2 Caldukia albolineata Side view of a rhinophore Figure 3 Caldukia albolineata Cerata of the living animal: left — view of inner surface, right — view of lateral surface Vol. 12; No. 3 THE VELIGER Page 281 Figure 4 Caldukia albolineata View of the right side of the body showing the insertions of the cerata and the apertures an = anus dorso-ventrally flattened buccal bulb. Salivary glands huge, folliculose, lie closely applied to the sides of the oesophagus and ventro-lateral walls of the stomach (in the one specimen examined the condition of the salivary glands was probably abnormal, the left gland extended behind the stomach along the main posterior duct of the digestive gland and ended at the origin of the second left lateral duct — the right gland was very small and barely reached the stomach). Oesophagus short, wide and muscular, runs from the centre of the upper surface of the buccal bulb to the fairly large banana-shaped muscular stomach which lies to the left of the mid-line. There are 3 main stomachal ducts of the digestive gland; the right and left anterior ducts are short and each opens into a wide longitudinal duct which extends along the edge of the anterior half of the notum on the left side and two- thirds on the right. Short lateral branches, simple and divided, arise along the sides of the longitudinal duct, a few on the inner side and many on the outer. The poste- rior duct, which shares a common opening into the stom- ach with the left anterior duct, is long; it runs along the left side of the gonad and then, just before the hind end of the pericardium, starts to bend over to the mid-line of the body, giving off as it does so, two lateral ducts to the left side. On reaching the mid-line, the main duct bends sharply, giving off as it does the first right lateral duct, to run posteriorly above the intestine, sending branches to the left side. It veers gradually to the left side of the anus and then curves to the right around the posterior end of the notum sending off short branches; all but the most posterior of the lateral ducts branch. Diverticula arise singly from the longitudinal ducts and side branches. rp = renal pore ra = reproductive apertures Each diverticulum is simple and extends almost to the tip of the ceras (Figure 6). The intestine arises on the left side from the posterior end of the stomach; it bends im- mediately through 180° and then describes a half circle around the front of the pericardium as it passes to the right side. On the right side the intestine continues to bend and passes below the posterior end of the pericardi- um to return to the left; it then bends again to run to the anus. Buccal Armature: Radula (Figure 7). Formula 6-1-6; the one specimen examined had a radula of 28 (including 6 developing) rows. Central tooth smallish, roughly tra- pezoidal; posterior face concave, upper edge notched to form a broad semilunar median cusp with a small apical denticle; the notched edge is serrulate and there is a denticle on each of the corners. The lateral teeth are peg-like; the inner 5 (2 and 3 are the largest) are fairly similar in shape with a broad cuspidate crown, the middle cusp being very large, and a somewhat sinuous and slightly tapered base (short in 5) bent towards the margin of the radula; the sixth (the outermost) is very small, almost rectangular with a single (median) cusp. Jaws (Figure 8). Strong, unequal, united dorsally by a thick band of chitin. Right jaw long, fairly narrow and curved with 4 large horny teeth at the anterior end. Left slightly shorter than the right, but broader and angular, with 2 large teeth. Nervous System: Although worked out in some detail it is not described here: the most important features are the long optic nerves and the fused cerebral and pleural ganglia. Page 282 THE VELIGER . Vol. 12; No. 3 2) LY BORK hort oe vd = Kon V, San BA Figure 6 Caldukia albolineata Preserved ceras (stained with borax carmine and cleared with cedar-wood oil) showing diverticulum of digestive gland Kidney: Figure 5. This organ lies dorsally between the front end of the pericardium and the anus: it is thin walled and consists of a long central sac and a number of lateral diverticula, some reaching almost to the edge of the notum; the anterior diverticula are long and irregularly lobed, those to the posterior are short and simple. The renopericardial duct (organ) is small and Figure 5 (<— adjacent column) Caldukia albolineata Dorsal view of the general anatomy an = anus bb = buccalbulb cns = central nervous system he = heart in = intestine ki = kidney Idg = left digestive gland ot = oraltube pc = pericardium pe = penis rd = renopericardial duct rdg = right digestive gland rp = renal pore sg = salivary gland st = stomach Wolw 12: No. 3 THE VELIGER Page 283 AS | Figure 7 Caldukia albolineata Radular teeth, half row C = central (rhachidian) Li = innermost lateral L6 = outermost lateral links the pericardium with the first large right diverticu- lum. The renal pore opens at the tip of the last large right diverticulum. Reproductive System: Figure 9. Hermaphrodite gland of 4 follicles, each joins separately, by a long ductule, to the common hermaphroditic duct which runs forward to the ampulla. The ampulla is ovoidal with a small chamber (or pouch) on the right side into which opens the herm- aphrodite duct and, by a short narrow duct, a small vesicle (the fertilization chamber). The vas deferens and oviduct arise separately, the former from the front end of the ampulla, the latter from the front end of the side chamber. The first third of the vas deferens is a narrow duct, the remainder is a very wide glandular portion (the prostate) ; the penis is conical and unarmed (Figure 10). The oviduct runs to the right, constricts and then forks, one of the branches leads to the albumen gland, the other to the female atrium. The bursa copulatrix is ovoid and is connected to the atrium by a long narrow duct, the vagina. Figure 8 Locality and Habitat: New Zealand, the South Island: Caldukia albolineata Otago Harbour, Aquarium Point, one specimen on the Jaws, view of inner surface under surface of a rock in the sublittoral fringe, 20 upper — right Jaw lower — left jaw January 1961. Page 284 THE VELIGER Vol. 12; No. 3 Figure 9 Caldukia albolineata Reproductive system, unravelled am = ampulla be = bursa copulatrix fa = female atrium fe = fertilization chamber fgm = female gland mass hd = hermaphrodite duct hg = hermaphrodite gland ov = oviduct po = pouch pr = prostate ps = penial sheath va = vagina vd = vas deferens Type: Holotype — a microscope slide of the radula and a colour photograph (35 mm Kodachrome transparency) of the one living animal collected at Aquarium Point, deposited in the Dominion Museum, Wellington (M. PATA) Caldukia rubiginosa Mi.tEr, spec. nov. Morphology: Figure 11. Extended length up to 12 mm. As the previous species except for the following details: rhinophores with up to 7 lamellae, lowest very small (Fig- ure 12) ; cerata fusiform (Figures 13, 14), in up to 4 rows. Colour: Dorsal part of the body, rhinophores, distal por- tion of cerata, opaque reddish brown; cerata transparent (except at base), upper half yellow, lower half colourless, latter divided by a band of opaque white (with blue iri- descence) which is broad to the centre of the body and narrow to the outside, diverticula apricot or pale brown; upper region of the side of the foot speckled with reddish brown, lower region, tail and sole transparent yellow or apricot — hermaphrodite gland visible as opaque pink bodies. Vol. 12; No. 3 THE VELIGER Page 285 Figure 10 Caldukia albolineata Penis, preserved (stained with borax carmine, cleared in cedar-wood oil) pe = penis ps = penial sheath pr = prostate Alimentary System: As Caldukia albolineata spec. nov. There is, however, a right post-anal branch of the digestive gland. Buccal Armature: Radula (Figure 15). A 9mm animal had a radular formula of 23 (including 5 developing rows) x 6:1-6. Teeth very similar to those of C. albolineata: central with weak serrulations, central cusp without an apical denticle, no denticles at the corners; laterals rather uneven in outline, inner 4 teeth with a small flange de- veloped on both the inner and outer sides of the central cusp. Jaws (Figure 16): as in C. albolineata, but the right jaw is slightly more angular. Kidney: Large, filling the dorsal region of the body cavity from the middle of the pericardium to the anus. More branched than in C. albolineata and the branches are so compacted as to give the organ an alveolate appearance. Reproductive System: Figures 17, 18. Very similar in plan to that of Caldukia albolineata. However, the ampulla is oblong, the hermaphrodite duct does not enter by way of a lateral swelling and there is no vesicle (fertilization chamber) at the side; also, a short, narrow, common duct leaves the front end of the ampulla and this bifurcates into vas deferens and oviduct. Locality and Habitat: New Zealand, the North Island: Goat Island Bay, near Leigh; on the under surfaces of rocks in the sublittoral fringe, feeding on the polyzoan a Figure 11 Caldukia rubiginosa Dorsal view of a living animal Beania magellanica (Busk) ; six specimens, one spawn band, 28 August 1961; two specimens, several spawn bands, 26 October 1961; two specimens, 26 February 1963. Page 286 THE VELIGER ) Vol. 12; No. 3 Type: Holotype: a specimen collected at Goat Island Bay, near Leigh, deposited in the Dominion Museum, Welling- ton, New Zealand (M. 22178). Food and Feeding Habits:' Caldukia rubiginosa feeds on the polyzoan Beania magellanica (BusK) which it tears apart with its large, strong dentate jaws. A single zooid is attacked — this and adjacent zooids are first smothered with mucus. When feeding, the mouth is opened wide and the buccal bulb thrust forward so that the jaws and radula are protruded (Figure 20). Jaw and radular movements are synchronized with those of the buccal bulb; when the latter is thrust forward the jaws and the two halves of the radula open, when withdrawn, they close. The polyzoan zocecium, which is usually grasped Figure 12 about the middle, is fractured by the large horny teeth Caldukia rubiginosa Side view of a rhinophore ™ Mentioned briefly in Morton « MILLER (1968) on p. 412 but the species is not named Figure 13 Figure 14 Caldukia rubiginosa Caldukia rubiginosa Cerata of a living animal; left drawing shows pigmentation and Preserved ceras (stained with borax carmine and cleared with diverticulum of the digestive gland cedar-wood oil) showing diverticulum of the digestive gland C Li _eenee re Figure 15 Caldukia rubiginosa Radular teeth, half row C = central (rhachidian) Li = innermost lateral L6 = outermost lateral Vol. 12; No. 3 THE VELIGER Imm Figure 16 Caldukia rubiginosa Jaws, view of inner surface upper — right jaw lower — left jaw of the jaws closing upon it and drawing it into the buccal cavity, assisted by a sharp contraction of the head on the firmly fixed foot. This is repeated many times until the zooid, or part of it, is torn from the colony (Figure 21). The polypide is completely macerated during the tearing process. The radula acts as a conveyor belt and transports the detached zooid, or fragment, to the oesophagus. The whole action is very rhythmical, there being an active phase of 10 - 25 seconds during which the animal makes 4 to 8 thrusts with its buccal mass, followed by a resting phase of 60 - 70 seconds. The nudibranch may take up to 35 minutes to detach a single zooid. The zocecia of the zooids ingested are not altered as they pass through the Figure 17 Caldukia rubiginosa Page 287 Reproductive system, unravelled be = bursa copulatrix ampulla fgm = female gland mass hg = hermaphrodite gland ov = oviduct ps = penial sheath pe va = vagina Figure 18 Caldukia rubiginosa hd = hermaphrodite duct pr = prostate vd = vas deferens Penis, preserved (stained with borax carmine, cleared in pe = penis cedar-wood oil) ps = penial sheath pr = prostate Page 288 THE VELIGER Vol. 12; No. 3 a Figure 19 Caldukia rubiginosa Drawing of an animal feeding on the polyzoan Beania magellanica (Busx) Figure 20 Caldukia rubiginosa Ventral view of the head of a living animal showing the buccal bulb thrust through the dilated mouth and the jaws and two halves of radula opened gut; they are, however, compacted into a firm string before being defaecated. Figure 21 Caldukia rubiginosa DISCUSSION Series of sketches showing an animal (head only shown) biting off a single zooid of Beania magellanica (Busk). é We ; Bottom — a ventral view of head with an avicularium (bitten off Colour and colour pattern clearly distinguish the two with the zooid) protruding from the mouth. A, B, C — letters species of Caldukia, described here, from each other and identifying the zooids Vol. 12; No. 3 THE VELIGER Page 289 from the type species, C. affinis (Burn). Briefly stated: C. rubiginosa has a reddish brown body and cerata with colourless, yellow and opaque white (blue iridescence) zones; C’. albolineata has a dull yellow body and a single opaque white line down each ceras; and C. affinis has a reddish fawn body marked mid-dorsally with yellow and fawn cerata speckled with minute red spots. The colours and patterns appear to be constant in C. rubiginosa and C. affinis. There are only minor morphological and ana- tomical differences between the three species. Most im- portant of these is the shape of the radular teeth, par- ticularly the central and the first and sixth laterals. In C. albolineata the central is broad with a wide median cusp, which, like the corners, is apiculate and serrulate. This tooth in C. rubiginosa differs in being longer (when viewed from above) and without the denticles on the cusp and the corners (though these may have been worn off in the animal examined). Caldukia affinis has a central tooth with a narrow blunt cusp and no denticles or serrulations. The first lateral tooth of C. affinis is almost rectangular, but in the other two species it has a comma-shaped base (like lateral teeth 2 to 5 of all 3 species); the median cusps of the first to fourth lateral teeth of C’. rubiginosa have small side flanges. The sixth tooth of C. affinis has a fairly long, pointed and bent base, whereas in the other 2 species it is very short and blunt. The jaws differ only slightly in outline. In the few specimens examined there were minor variations in the branching of the digestive gland, but these did not appear to be constant enough to be used to separate the species. The reproductive system is fundamentally similar in the 3 species; however, that of C. albolineata differs from the systems of the other 2 species in the following 2 respects: (1) the male and female ducts leave the ampulla separately, i.e., there is no anterior common duct, and (2) the fertilization cham- ber is a vesicle at the side of the ampulla. SUMMARY Two new species of the janolid nudibranch genus Caldukia Burn & MILLER are described, viz. C. albolineata and C. rubiginosa. The anatomy of C’.. albolineata is given in some detail and the feeding habits of C’. rwbiginosa, which preys on the polyzoan Beania magellanica (Busk), are briefly described. The two new species and the type of the genus, C. affinis (BURN) are compared; colour and pattern are the principal distinguishing characteristics; small differ- ences in the radular teeth and reproductive system are of secondary importance. LITERATURE CITED Burn, RoBERT 1958. Further Victorian Opisthobranchia. Soc. Australia 2: 20 - 36 Burn, Ropert & MicHAEL CHARLES MILLER 1969. A new genus, Caldukia, and an extended description of the type species, Proctonotus ? affinis Burn, 1958 (Mollus- ca: Gastropoda: Arminacea, Antiopellidae). Journ. malacol. Soc. Australia 12: 23 - 31 Marcus, ERNST 1955. | Opisthobranchia from Brazil. Bol. Fac. Fil. Univ. Sao Paulo, Zoologia 20: 89 - 200; plts. 1 - 30 1958. | On Western Atlantic opisthobranchiate gastropods. American Mus. Novitates no. 1906: 1 - 82 Miter, MicHAEL CHARLES in press, A new genus and species of the nudibranch family Ja- nolidae (Mollusca; Gastropoda, Opisthobranchia) from New Zealand waters. Journ. nat. hist. London Morton, JoHN Epwarp & MicHAEL CHARLES MILLER 1968. The New Zealand sea shore. Collins, London and Auckland; 638 pp. Journ. malacol. Page 290 THE VELIGER Vol. 12; No. 3 Occurrence of a Rare Squid, Chaunoteuthis mollis APPELLOF (Family Onychoteuthidae) in the Indian Ocean BY K. N. NESIS Institute of Oceanology, USSR Academy of Sciences, Moscow, USSR (Plate 42; 1 Text figure) THE CEPHALOPOD FAUNA of the Indian Ocean is by far not as well investigated as that of the Pacific and Atlantic Oceans. At present there are nearly half as many species of oceanic squids (Oegopsida) known in the Indian Ocean as in the Atlantic. From the general zoogeographic con- ception of the richness and diversity of the Indo-West-Pa- cific fauna a contrary relation might be supposed. The number of species of neritic squids (Myopsida) for instance, which can be caught easier than Oegopsida and so could » be better studied, is by a third as large in the Indian Ocean as in the Atlantic. Now the investigations of the Indian Ocean are intensified and so our knowledge of its fauna, and its cephalopods in particular, has increased. Two specimens of the rare squid Chaunoteuthis mollis ApPELLOF, 1891, both in excellent condition, have been found in a small collection of pelagic cephalopods from stomachs of handsawfishes (Alepisaurus spp.), captured by Mr. V. G. Osipov of the Pacific Research Institute of Fisheries and Oceanography, Vladivostok, in the tropical eastern Indian Ocean aboard the R/V Orlik. So far, this species has been found only in the Atlantic Ocean and the Mediterranean Sea. A review of the collection and some considerations about the feeding of Alepisaurus and the importance of cephalopods in their food are given in an- other article (Parin, Nesis & Vinocrapov, 1969). The present paper will deal only with the description of the Chaunoteuthis mollis found. I owe thanks to Dr. N. V. Parin for making the material available, and to Dr. Johanne Kjennerud of the Zoologi- cal Museum, Bergen, for the re-investigation of Appellof’s type specimen in that Museum and for sending me valu- able information. TEUTHIDA Oegopsida ONYCHOTEUTHDAE Chaunoteuthis mollis APPELLOF, 1891 From the stomach of an Alepisaurus sp.: 13°00’S, 101°26’ E, November 25, 1963, two specimens, both females. Dor- sal mantle length (DML) of no, 1: 121 mm, of no. 2: 125 mm; total length 194mm and 204 mm, respectively. Weight of both specimens together: 40.4 g (Plate 42, Fig- ure 1). The body is very soft, flabby, the skin thin, but rather firm. The mantle muscles are of gelatinous consistency. The mantle form is conical; it is widest at the anterior margin: mantle width = 45 to 46% DML. The anterior margin of the mantle shows a small blunt projection on the dorsal side and hardly visible lateral projections. The ventral margin is very slightly emarginated, nearly straight. The ventral mantle length is 96 to 98% DML. The gladius is not visible through the mantle, but there is a narrow dorsal groove over the gladius between the fins. The fins are transversely-rhombic; their length is 46 to 49% DML, the width is 96% DML. The head is a little narrower than the mantle, flattened dorsally; its width is 17 to 19% DML. There are some 8 nuchal folds on either side. The eyes are big; their length is 114 to 12% DML; the width is 10 to 104% DML. The eyelid is circular, with a shallow sinus anteriorly. One luminous organ, long and band-like, with slightly widened edges and a narrowed middle part is situated on the ventral periphery of the THE VELIGER, Vol. 12, No. 3 [Nests] Plate 42 Figure 1 Figure 2 Figure 1: Chaunoteuthis mollis APPELLOF. Specimen no I Two-thirds natural size. Figure 2: Chaunoteuthis mollis AppeLOr. Eye. An ocular photo- phore is seen. Three times natural size. Vol. 12; No. 3 THE VELIGER Page 291 eye-ball. The organ’s colour is brightly orange. Its dimen- Sions in) no! — 1/2) <3)mm) in) no! 27—" 14<3)mm (Plate 42, Figure 2). The funnel extends almost to the vertical of the anterior eye margin. The funnel groove is triangular, posteriorly restricted by a softly arched skin ridge. The funnel cartilages are simple, lengthened, slightly broader posteriorly, with a narrow, deep, very slightly S-shaped groove. The mantle cartilages are simple thin ridges nearly twice as long as the grooves of the funnel cartilages. The arms are nearly equal in length, their order is 2°3°4-1. The length of the dorsal arms is 31 to 36% DML, of the dorso-lateral it is 403 to 464%; that of the ventro-lateral arms is 38 to 45% and that of the ventral arms is 34 to 40% DML. All arms have swimming mem- branes, which are narrow at the dorsal arms, wider at the dorso-lateral ones and rather wide at the ventro-lateral and ventral arms. Protective membranes are nearly in- conspicuous. The suckers are small, their horny rings without dentition, and callose distally. The ring callus is so great that the space of the ring looks excentric or like the pupil of an octopus or a cuttlefish, and sometimes is even closed totally. The tentacles are reduced to only short scraps of stems; their length is 5 to 64% DML. The gladius is of a deep brown colour, narrow, strongly convex, especially in its posterior half; the vane is slightly widened, the lateral edges are not thickened, transparent. The colour of the animal is a pale brown above and an even more pale brown below. Large and small brown chromatophores are dispersed so that a characteristic eye- spot pattern arises, especially in the posterior part of the mantle and on the dorsal side of the fins. The ventral side of the fins (except for the edges) and of the first 3 pairs of the arms, and the dorsal side of the ventral arms are not coloured at all. No “very fine scales,” that have been seen in this species by CLarKE & Maui (1962) were found in the present specimens. The stripes of spermatophores — typical for this spe- cies and almost unique among cephalopods — are found in both females. They are located at one side of the vent- ral mantle surface, in the area of the mantle-locking cartilages. Both females have only one such stripe: no. 1 at the left and no. 2 at the right. The length of the stripes is 35 mm and 27 mm, respectively; they start 4mm from the anterior edge of the mantle. The number of spermato- phores is 26 and 36, respectively; the spermatophores are attached to the outer surface of the mantle in a narrow and shallow groove that looks like a closed cicatrice. The shape of the spermatophores is similar to that of a sipun- culid worm of the genus Golfingia, the “bodies” of the spermatophores, that is the sperm reservoirs, are firmly immersed in the tissues of the mantle, the “heads” and “necks” protrude outward. The eggs of both females are not much developed; their size is 0.35 to 0.40 mm. DISCUSSION At present there are 7 specimens of Chaunoteuthis mollis known: 6 adults (ApPELLOF, 1891; LONNBERG, 1896; PrerFer, 1912; Jousrn, 1920; Grimpz, 1921, and Torcuio, 1967) and one young with a mantle length of 1.25 cm (Nasr, 1923). All the adults were found on the surface of the Mediterranean Sea and in the Eastern Atlantic Ocean (Text figure 1). The only young specimen was caught also in the Mediterranean Sea at a depth of 150 m. The specimens investigated are in accord with the de- scriptions of preceding authors except for the eye photo- phores, the absence of which is mentioned even in the generic diagnosis (PFEFFER, 1912). At my request Dr. Johanne Kjennerud re-investigated Appelof’s type speci- men kept in the Bergen Museum and was so kind to inform me that on the only eye-ball of this specimen there is a structure which may be a luminous organ. It consists of a band of very fine dark chromatophores with a layer behind, which seems to be iridescent. As for their shape and position the luminous organs of Chaunoteuthis mollis are very like the organs of Ctenop- teryx siculus (family CTENOPTERYGIDAE). All 8 now known adult specimens of Chaunoteuthis mol- lis are females, and 7 of them have had stripes of sperma- tophores on the outer surface of the mantle: 4 on both sides of the median line, 3 on one side only. The number of spermatophores in one female may reach 100 (Tor- cHIo, 1967). The stripes of spermatophores start always a little off the anterior edge of the mantle and extend nearly parallel to the median axis of the body. But their length may differ; they may diverge or fork. Probably they are produced at copulation, once in the life, perhaps even in the youth of the female. Grimpr (1921) and Torcuio (1967) speculated that the male cuts the skin of the female with his beak and places the spermatophores along the cut. Then the edges of the wound close and the spermatophores remain firmly fixed in the tissues of the female. This speculation seems to be correct. Chaunoteuthis mollis was considered a deep-water species (GrimpE, 1921). Probably this is not so. The hooks of the long line, by which the Alepisaurus that had swallowed the Ch. mollis were caught, were at a depth Page 292 THE VELIGER Vol. 12; No. 3 Figure 1 Distribution of Chaunoteuthis mollis (@ = known records; © = new record) of 80-90 to 120-150 meters. The main habitat of Alepi- Saurus is in the lower epipelagic and upper mesopelagic (Parin, 1968; Parin, Nests « ViNocRADOV, 1969). It is most probable that Ch. mollis inhabit the lower part of the surface zone (epipelagic) and the transitional zone (mesopelagic). SUMMARY An onychoteuthid squid, Chaunoteuthis mollis, is recorded for the first time in the tropical eastern Indian Ocean: 2 females were found in the stomach of an Alepisaurus sp. An ocular photophore, previously unknown, is described. It is supposed that Ch. mollis inhabit the lower epipelagic and mesopelagic zones. LITERATURE CITED APPELLOF, A. 1891. Teuthologische Beitrage, II. Chaunoteuthis n. g. Oegop- sidarum. Bergens Mus. Aarsber. for 1890, no. 1: 1-29 Ciarxe, M. R. « G. E. Maur 1962. _A description of the “scaled” squid, Lepidoteuthis grim- aldi Jounin, 1895. Proc. Zool. Soc. London 139 (1): 97 - 118 GrimPE, GEorc 1921. Teuthologische Mitteilungen, VI. Das Leipziger Stiick von Chaunoteuthis mollis ApPpELLOF. Zool. Anz. 52 (12/13): 289 - 296 Jousin, Lours 1920. Céphalopodes provenant des campagnes de la “Prin- cesse Alice” (1893-1910). (3° série). Rés. Camp. Sci. Monaco 54: 1-113; 14 plts. LONNBERG, E. 1896. Notes on some rare cephalopods. skaps-Akad. Férhandl. 8: 603 - 612 Narr, ADOLF 1923. Die Cephalopoden. Systematik. Fauna u. Flora Neapel Monogr. 35, 1 (1), no. 2: i-xiv+149 - 863; 473 figs. Parin, N. V. 1968. Ichthyofauna of the oceanic epipelagial. Moscow: 1 - 186 (in Russian) Parin, N. V, K. N. Nests « M. E. Vinocrapov 1969. Materials on the feeding of the Alepisaurus in the Indian Ocean. Voprosy Ikhthiologii 9 (3/561) : 526 - 538 (in Rus- sian) PFEFFER, GEorc J. 1912. Die Cephalopoden der Plankton-Expedition. Zugleich eine monographische Ubersicht der Oegopsiden Cephalopoden. Ergsb. Plankton-Exped. Humboldt Stift. 2: i-xxi+1-815; Atlas 48 plts. Torcuio, M. 1967. Eccezionale reperto di Chaunoteuthis mollis (ApPEL- LOF) nello Stretto di Messina. Natura (Milano) 58 (3): 193 - 207 Ofv. Kgl. Veten- “Nauka”, Vol. 12; No. 3 THE VELIGER Page 293 A Note on the Chromosome Number and Interrelationships in the Marine Gastropod Genus Thais of the United States Pacific Coast ' BY MUZAMMIL AHMED’ AND ALBERT K. SPARKS College of Fisheries, University of Washington, Seattle, Washington 98105 (Plate 43) SEVERAL SPECIES OF MARINE SNAILS belonging to the family Muricidae (Gastropoda : Streptoneura) inhabit the Pacific Coast of North America. The genus Thais is represented by 4 species, namely, T: lamellosa (GMELIN, 1791), T. lima (GmeEttn, 1791), T: emarginata (DESHAYES, 1839), and T: canaliculata (Ductos, 1832). Although these are customarily recognized as four distinct species, K1n- carp (1957, 1964) considers the last three as only “morphs” of a single polytypic species, T: lima. Thais lamellosa and T. canaliculata are easily distinguished but specimens of T. lima and T. emarginata show intergradation in shell morphology and are difficult to tell apart. The West Coast species and morphs of Thais are ex- tremely abundant on exposed and sheltered rocky coasts. They display a wide variety of form, sculpture and color. A pelagic larval stage is absent and the young animals emerge from egg capsules which are deposited in large numbers by the snails almost throughout the year. The dispersal of these snails would seem to be restricted to the immediate vicinity where they emerge from egg capsules. The presence of mud or sand around rocks and increasing depths constitute barriers for their migration. As a conse- quence “microgeographical” populations are established on different islands and even on isolated stretches of * Contribution No. 313 from the College of Fisheries, University of Washington, Seattle, Washington 98105 2 Permanent address: Department of Zoology, University of Kar- achi, Karachi, Pakistan land on the same beach. The conditions for genetical differentiation are highly favorable in such populations. We have undertaken an investigation of the chromo- somes of the above named species of Thais from the West Coast of the United States in order to elucidate the cyto- genetic structure of their microgeographical populations. A previous study of similar populations of the European T. lapillus (Linnakzus, 1758) by Statcer (1954, 1957) indicated the existence of numerical and structural chro- mosome polymorphism. The extreme forms of this species occurring on exposed and sheltered beaches possessed haploid numbers of 13 and 18 respectively and forms present on intermediate wave exposed beaches had inter- mediate numbers. Centric fusions due to reciprocal trans- locations were shown to be responsible for the Robertsonian nature of the chromosome polymorphism. NisHrKAWA (1962) examined 3 species of Thais, T: bronni (DUNKER, 1860), T: clavigera (Kiister, 1858), and T: luteostoma (Hotten, 1802) from Japan and found 30 to be the common haploid number. He did not find any numerical chromosome polymorphism. We have examined chromosomes from oocytes obtained from egg capsules. The egg capsules of the 4 species were collected from the coastline of the States of Washington, Oregon and California. The standard aceto-orcein squash technique of chromosome preparations was routinely used. Although Thais lima and T. emarginata capsules contain nurse eggs, 7: lamellosa does not and the shape and size of its egg capsules and the number and size of its oocytes Page 294 also differ from the other two. We found that T: canalicu- lata egg capsules and oocytes possess a greater resemblance to those of T: Jamellosa rather than to those of T: lima and T: emarginata. A haploid chromosome number of 35 is common to the 4 species. Three other marine gastropod species, Ceratostoma (Purpura) foliatum (Gmeuin, 1791), Oci- nebra japonica (DUNKER, 1860) and Fusitriton oregon- ensis (REDFIELD, 1848), which were examined by us also share this number. In prometaphase and metaphase-I plates 35 bivalents were counted with clarity. In all cases a definite prometaphase stretching of bivalents was ob- servable (Plate 43, Figures 1 and 2) as in Thais lapillus (StaicEr, 1954). In the 4 species of Thais, the prometa- phase bivalents may stretch as long as 40m or more. Bivalents were generally rod-like, formed by acrocentric (subterminal) or telocentric (terminal) chromosomes and possessed a single chiasma at prometaphase or metaphase- I. Associations of meiotic bivalents, such as quadrivalents and, in some cases, linear trivalents, were observed so that meiotic plates were polymorphic for interchanges or translocations. In a total of 100 animals or more the chromosome number was usually N = 35. In mitotic plates of the 4 species 70 chromosomes were usually seen. The majority of chromosomes were acrocent- ric or telocentric but metacentrics were present. The chromosome number is very large and difficult to work with. A detailed study of the meiotic and mitotic chromo- somes of several populations is being made despite this difficulty. This study of egg capsules, oocytes, and chromosomes of several populations of 'Thais forms and species throws THE VELIGER Vol. 12; No. 3 some light on the confused status of their taxonomy and interrelationships. We are inclined to conclude tentatively that while T: lima and T. emarginata may be the morphs or forms of the same species, T: lamellosa and T. canalt- culata are distinct species and perhaps closer to each other than to T. lima and T. emarginata. Kincam’s suggestion (1964) that T: lima, T: emarginata and T: canaliculata be consolidated under one species may be valid only for the first two of this series. Thais canaliculata shows consider- able differences in shell morphology, shape of egg capsules and number and size of oocytes. LITERATURE CITED Kincaip, TREVOR 1957. Local races and clines in the marine gastropod Thais lamellosa (GmEuIN). A population study. Calliostoma Press 1964. Notes on Thais (Nucella) lima (GMELIN), a marine gastropod inhabiting areas in the North Pacific Ocean. Calliostoma Company, Seattle. NISHIKAWA, SHYOHEI 1962. A comparative study of chromosomes in marine gastro- pods with some remarks on cytotaxonomy and phylogeny. Journ. Shimonoskei Coll. Fish. 11 (3): 149 - 186 STAIGER, HANSRUDOLF 1954. | Der Chromosomendimorphismus beim Prosobranchier Purpura lapillus in Beziehung zur Okologie der Art. Chro- mosoma 6: 419 - 478 1957. | Genetical and morphological variation in P lapillus with respect to local and regional differentiation of population groups. Coll. Intern. Biol. Mar. St., Roscoff; L’Année Biol. 3: 33; fasc. 5-6: 252 - 258 THE VELIGER, Vol. 12, No. 3 [AHMED & Sparks] Plate 43 Figure 1 Meiotic bivalents in a prometaphase plate of Thais emarginata. Approximately X 1000. Phase contrast. Figure 2 Camera lucida drawing of prometaphase meiotic bivalents of Thais emarginata. vi 0h Vol. 12; No. 3 THE VELIGER Page 295 Five New Species of Terebra from the Eastern Pacific BY TWILA BRATCHER 8121 Mullholland Terrace, Hollywood, California 90046 AND R. D. BURCH P.O. Box 133, Downey, California 90241 (Plate 44) IN EXAMINING the numerous specimens of West American Shy — Laura Shy Collection, Westminster, Terebridae made available to us during the past two years, California we have encountered several species which have not been SU — The Conchological Collection of Stanford previously described. These species have been seen with University some frequency in several of the larger institutional col- Thomas -—- Lawrence Thomas Collection, Morro Bay, lections as well as in private collections. California Terebra species from West America, in several instances, .USNM -— United States National Museum exhibit variations in shell characteristics which make iden- YPM — Yale University Peabody Museum of tification very difficult unless a long series of comparison specimens is available, and good protoconchs are a desir- able aid in separating species which have somewhat simi- lar shell characteristics. Abbreviations have been used for a number of the institutional collections cited here; these, along with the location of the private collections cited, are as follows: AHF — Allan Hancock Foundation (Material on loan to the Los Angeles County Muse- um of Natural History) AMNH~ - American Museum of Natural History ANSP — Academy of Natural Sciences of Philadelphia B&B — Bratcher and Burch Collection, Los Angeles, California BM(NH) -— British Museum (Natural History) CAS — California Academy of Sciences DMNH_ -— Delaware Museum of Natural History Frisbey | — Jeanne Frisbey Collection, Port Isabell, Texas LACM __— Los Angeles County Museum of Natural History SBMNH - Santa Barbara Museum of Natural History SDMNH - San Diego Museum of Natural History Natural History Terebra shyana BRATCHER & BURCH, spec. nov. (Plate 44, Figures 9, 10) Description: Size medium, slender; color dark buff with darker fulvous blotches; whorls slightly convex with noded subsutural band set off by well marked suture and sub- sutural groove; nucleus of 3 glassy slender whorls; early sculpture of numerous slightly curved axial ribs which are equal to their interspaces and of evenly spaced spiral cords (4 on 3™ postnuclear whorl) which cross the ribs faintly; ribs continuous from suture to suture with sub- sutural groove forming elongate nodes on band; in later whorls axial ribs become slightly narrower than inter- spaces, spiral cords crossing ribs form slight nodes giving a cancellate appearance, and spiral cords are more nu- merous (6 on penultimate whorl) and less evenly spaced; body whorl of average length with noded axial ribs continuing to periphery and fading out posterior to keel of siphonal fasciole; aperture semi-elongate; outer lip thin with color blotches showing through; columella curved with a slight plication, moderately laminated; siphonal fasciole striate with sharp posterior keel; anterior Page 296 canal broad and long; length 26.0 mm; diameter 5.6 mm; 14 whorls plus nucleus. Holotype: LACM, Type Collection no. 1249. Type locality: All specimens of the type material were collected at Manzanillo, Colima, Mexico, 19°02’ N Lat., 104°21’W Long.; 17-40 fathoms; by Laura Shy and Jeanne Frisbey. Paratypes: Paratypes are deposited in the following col- lections: CAS, Department of Geology, Type Collection no. 13280; SU Conchological Collection no. 9992; USNM no. 679481; Shy; Frisbey;B & B no. 742. Other material examined: In addition to two lots of type material, we have examined 9 lots of this species: CAS no. 27581 from near Santa Isabel Island, Gulf of California; AHF no. 1031-40 from Santa Maria Bay, outer coast of Baja California; AHF no. 765-38 from Chacaua Bay, Mexico, at 5 - 10 fathoms; AHF no. 1753-49 from north of Coyote Point, Gulf of California; AHF no. 273-34 from Tenacatita Bay, Mexico, at 45 fathoms; AMNH no. 88725 from the Gorda Banks, Gulf of California; AMNH nos. 77796 and 77826 from Coronados Islands, Gulf of California, Mexico. Largest specimen examined: length 36.1 mm; diameter 7.5 mm. Discussion: Specimens vary in the number of axial ribs and spiral cords. One of the largest specimens examined has ribs much narrower than the interspaces and only 4 rows of unevenly spaced spiral cords which cross the ribs without producing a cancellate appearance. The largest specimen appears cancellate from the first postnuclear whorl through the body whorl. Terebra shyana resembles several other Terebra species which occur in the Indo-Pacific and Panamic regions. It can be separated from T: panamensis Datu, 1908, by the latter’s heavier, more cancellate sculpture and less conspic- uous subsutural band, while T: turrita E. A. Smiru, 1873, of Australia, T. serotina Apams & ReeEve, from Ja- pan and the Philippine Islands, and T. textilis Hinps, 1844, of the Indo-Pacific, may be distinguished from T. shyana by their more cancellate sculpture, flatter whorls, protoconchs and style of columella. Another Panamic Terebra, the description of which is presently in press, has a rather close superficial resemblance to T: shyana, there- fore a close examination of this species is desirable, espe- cially of the protoconch and of the spiral sculpture anterior to the periphery of the body whorl. This species is named in honor of Mr. and Mrs. Carl Shy of Westminster, California, for their having collected the first specimens of this species which came to our atten- THE VELIGER Vol. 12; No. 3 tion and for their generosity in having made their large collection of specimens available for study. Terebra brandi BRATCHER & BURCH, spec. nov. (Plate 44, Figures 5, 6) Description: Size medium small, slender; color bluish gray; whorls slightly convex with moderately convex sub- sutural band marked by impressed suture and subsutural groove which crosses axial ribs after the 4° postnuclear whorl; nucleus of 4 dark brown, shiny, smooth whorls; sculpture consistent throughout except that subsutural band becomes discernible after 4 postnuclear whorl; axial sculpture of slightly curved ribs narrower than interspaces on both whorl and band; spiral sculpture of rows of evenly spaced spiral grooves which do not cross axial ribs, 6 on penultimate whorl, 3 on subsutural band; body whorl of medium length with axial ribs ending at periphery and interspaces divided by 7 rows of spiral grooves; anterior to periphery 7 unevenly spaced spiral grooves extend to siphonal fasciole; aperture moderately elongate; outer lip thin; columella brown with slight curve, very faint plication, light lamination; siphonal fas- ciole striated with posterior keel; anterior canal moder- ately long, curved, medium width; length 16.9 mm, di- ameter 3.9 mm; 10 whorls plus nucleus. Holotype: LACM —- AHF, Type Collection no. 1252. Type locality: Petatlan Bay, Mexico, 17°31’N Lat., 101°27’ W Long.; Allan Hancock Pacific Expedition col- lecting station 265-34; 5-10 fathoms on hard sand and shell bottom. Paratypes: One paratype; LACM - AHF, Type Collec- tion no. 1253; very poor conditicn. Other material examined: In addition to the type lot, AHF 702-37 from Angeles Bay, Baja California, Mexico, at 18 fathoms; Shy Collection from Manzanillo, Mexico, 7-8 fathoms; AHF 584-26 from Conception Bay, Baja California, Mexico, intertidal; Frisbey Collection from Manzanillo, Mexico, 15-40 fathoms; LACM Hill Collec- tion from Bay of Dulce, Mexico; AHF 763-38 from Cape Corrientos, Mexico, 5 - 10 fathoms; LACM no. B-16 from Taboga Island, Panama, 5 fathoms; USNM 566896 from Mazatlan, Mexico; USNM 426749 from Peru; B « B no. 273 from Panama Bay, Panama, intertidal. Except for the type lot and one other, each of which contains 2 specimens, all lots examined were of one speci- men each. Largest specimen examined: USNM 566896; length 24.1 mm; diameter 4.6 mm. Vol. 12; No. 3 Discussion: The variation exhibited among the specimens examined is confined to the color, which may be lavender gray, bluish gray or beige gray. Several species of Panamic Terebra somewhat resemble T. brandi in sculpture. Terebra berryi CAMPBELL, 1961, has a larger apical angle, more convex whorls with a depressed subsutural band, a more pronounced and num- erous spiral sculpture and different style of color and color pattern; while 7: churea CAMPBELL, 1964, has a shorter protoconch, more pronounced subsutural band and more numerous spiral sculpture than T: brandi. The western Atlantic Ocean and Gulf of Mexico species, T. protexta (Conrap, 1848), and T: glossema SCHWENGEL, 1940 and 1942, have some sculptural resemblance but may be separated by their axial ribs which continue anterior to the periphery of the body whorl and by their columellas which are more curved or twisted than the slightly curved columella of T: brandi. This species is named for Dr. Louis M. Brand of Houston, Texas, in recognition of his generous assistance and early encouragement of our study of the Terebridae. Terebra dorothyae BRATCHER & BURCH, spec. nov. (Plate 44, Figures 7, 8) Description: Size medium; color brown, with portions of subsutural band and nodes slightly lighter; early whorls somewhat convex and later whorls almost flat, with mod- erately convex subsutural band marked by impressed suture and broad shallow subsutural groove; nucleus partially missing; first postnuclear whorl glassy with slightly curved axial ribs narrower than interspaces; next 4 postnuclear whorls with ribs extending from node on subsutural band to following suture; in later whorls, nodes on band become elongate with ribs on remainder of whorl broken into nodes by spiral grooves, 5 on penulti- mate whorl; body whorl long, with 2 rows of spiral nodes wide-set and 3 rows, smaller and closer together, posterior to periphery; anterior to lighter band of color at peri- phery, 3 rows of cords form small nodes where they cross axial ribs, followed by 3 rows of cords which do not form nodes; aperture elongate; outer lip thin with light peri- pheral band and pattern of nodes showing through; co- lumella slightly curved with no plication; siphonal fasciole heavy, striated, with exceptionally large posterior keel; anterior canal broad; length 29.9 mm; diameter 6.5 mm; 11 whorls plus portion of nucleus. Holotype: LACM - AHF, Type Collection no. 1250. Type locality: AHF Pacific Expedition collecting stations THE VELIGER Page 297 770-38 and 929-39; near San Jose, Guatemala; 13°53’ N Lat., 91°09’ W Long. Paratypes: LACM - AHF, Type Collection no. 1251; CAS, Department of Geology, Type Collection no. 13281; SU Conchological Collection no. 9993; SBMNH, Type Collection no. 27141; SDMNH, Type Collection no. 51249; AMNH no. 154674; USNM no. 679482; YPM no. 12- 15635; BM(NH) ; DMNH no. 22421; ANSP no. 316223. Other material examined: AHF 762-28 from inner Gorda Bank, Gulf of California, Mexico, 60 fathoms; CAS 35006 from coast of Michoacan, Mexico; Shy Collection from Santiago Bay, Manzanillo, Mexico, 7 - 8 fathoms; Frisbey Collection from Manzanillo, Mexico, 15-40 fathoms; LA CM Hill Collection from Panama Bay, Panama; LACM no. A5498 from the Galapagos Islands. Largest specimen examined: LACM no. A5498; length 36.0 mm, diameter 7.7 mm; nucleus missing. Discussion: This species exhibits little variation among the specimens examined. In some specimens the light color band at the periphery of the body whorl and the lighter subsutural band are very distinct while in other specimens these features are almost non-existent. In occasional spe- cimens the axial ribs and spiral cords crossing them are conspicuous, while in others only the nodes are evident. Terebra dorothyae has little resemblance to other spe- cies of Terebra; however, some variations of other species should be considered in making identifications. The Japan- ese species, T: pustulosa E. A. Smitu, 1879 (= T. granu- losa E. A. Smiru, 1873, not Lamarck, 1822) has a weak- ly but broadly impressed subsutural groove and fewer rows of nodes than are found in T: dorothyae. Of the Pan- amic species which exhibit rows of spiral nodes, T: tuber- culosa Hinps, 1844, is a broader and heavier shell with more conspicuous subsutural band and fewer rows of spiral nodes, while T: cracilenta Li, 1930, also has a broader apical angle and heavier shell with more pro- nounced subsutural band and nodulous sculpture than T. dorothyae. Both T: ropert Prtspry & Lowe, 1932, and T. adairensis CAMPBELL, 1964, are slender species, as is T. dorothyae, but each of these has only 2 rows of nodes on each whorl, one posterior and one anterior to the suture. Terebra glauca Hinps, 1844, might also be com- pared, although this species is consistently broader, less uniformly noded or colored, and the columella more slan- ted than is found in specimens of T: dorothyae. This species is named in honor of Mrs. Dorothy Brown of San Diego, California, in recognition of her generosity in making specimens available for study and of her inter- est in conchology. Page 298 Terebra allyni BraTCHER & BURCH, spec. nov. (Plate 44, Figures 1, 2, 3, 4) Description: Size medium; color beige mottled with rust brown; whorls flat with slightly convex subsutural band set off by suture and shallow subsutural groove; nucleus of 14 dome shaped glassy whorls; first 2 postnuclear whorls translucent with almost straight ribs about equal to interspaces and no noticeable subsutural band or spiral sculpture; in next 6 whorls ribs become more widely spaced, starting as small elongate nodes on subsutural band, and wide but feeble spiral cords develop which do not cross ribs; after 6 postnuclear whorl wide spiral cords, though inconspicuous, cross ribs forming rounded nodes, 4 rows on penultimate whorl; fine axial striae form between rows of nodes and cross subsutural band; body whorl of average length with 4 rows of nodes, the anterior being at the periphery, followed anteriorly by a broad shallow groove and 4 rows of smaller nodes; anterior to periphery spiral sculpture becomes finer, more numerous, and continues to keel of siphonal fasciole as do axial striae; aperture elongate; outer lip sturdy; colu- mella straight with no plication, thinly laminated; siphon- al fasciole striated with posterior keel lacking in strength; — outer canal straight, broad; length 25.8mm; diameter 6.3 mm; 12 whorls plus nucleus. Holotype: CAS, Department of Geology, Type Collection no. 13278. Type locality: CAS station 23779, east shore of Maria Madre Island, Tres Marias Group, 21°35’ N Lat., 106°26’ W Long.; 5 to 10 fathoms. Paratypes: CAS Type Collection no. 13279; LACM Type Collection no. 1254; SBMNH Type Collection no. 27142; SU Conchological Collection no. 9995; SDMNH Type Collection no. 51248; USNM no. 679534; AMNH no. 154675; ANSP no. 316224; DMNH Type Collection no. 22421; BM(NH) ; B&B Collection no. 743. THE VELIGER Vol. 12; No. 3 Other material examined: In addition to the type lot of 61 specimens, many of which are immature, we have examined 2 specimens, CAS 29894, Margarita Island, Lower California, Mexico; 3 specimens, CAS 23810, Es- piritu Santo Island, Gulf of California; 1 specimen AM NH 74171, Maria Madre Island, Tres Marias Group, Pu- ritan Expedition; 1 specimen, AMNH, San Juanito Is- land, Tres Marias Group, Puritan Expedition; 1 specimen, LACM 66-8, Santa Margarita Island, intertidal to 6 feet; 15 specimens, LACM 65-16, Banderas Bay, Jalisco, Mexico, 10 - 15 fathoms; USNM 564817, Santa Inez Bay, Gulf of California. Largest specimen examined: LACM 65-16; length 39.1 mm; diameter 8.8 mm. Discussion: The smaller lots of specimens examined, which contain 1 or 2 specimens each, have only 1 row of spiral nodes at the periphery of the body whorl (Plate 44, Figures 3 and 4). These sharply rounded nodes are formed on axial ribs which fade completely at the poster- ior as well as the anterior portion of the whorl. This variation in sculpture is the only form we have seen from several of the collecting stations, although occasionally it is found among specimens which contain more sculpture. The rows of spiral nodes vary from 0 in some specimens to 4 in others examined. Occasional individual specimens are more slender than others, and some have a more convex subsutural band with larger nodes. The color varies little among specimens examined, with the exception of lot LA CM 65-16 which is light grayish brown with rust colored blotches between the nodes of the subsutural band. Several species of Indo-Pacific and Panamic Terebra have a superficial resemblance to T: allyni with T: specil- lata Hinps, 1844, resembling the more sculptured form. Terebra specillata has a more cancellate sculpture with more prominent subsutural band and consistent heavy sculpture through all whorls than T: allyni. The less sculp- tured forms of T. allyni resemble T: conspersa Hinps, 1844, but the latter has numerous incised interstitial spiral Explanation of Plate 44 Figure 1: Terebra allyni BRATCHER & BurRcH, spec. nov. Holotype CAS no. 13278 X 34 Figure 2: Terebra allyni. Hypotype, CAS no. 13279; nucleus Figure 3: Terebra allyni. Hypotype, CAS no. 13279; variation of sculpture xX 3 Figure 4: Terebra allyni, dorsal view of same shell as in Figure 3 Figure 5: Terebra brandi BratcHER & Burcu, spec. nov. Holotype LACM - AHF no. 1252 : X 34 Figure 6: Yerebra brandi, nucleus of same shell as in Figure 5 Figure 7: Terebra dorothyae BRATCHER & Burcu, spec. noy. Holo- type LACM - AHF no. 1250 X 3 Figure 8: Terebra dorothyae. Paratype LACM - AHF no. 1251 Nucleus Figure 9: Terebra shyana BraTCcHER & BurcH, spec. nov. Holotype LACM - AHF no. 1249 XK 3 Figure 10: Terebra shyana, nucleus of same shell as in Figure 9 Figure 11: Terebra hancocki BRATCHER & BuRcH, spec. nov. Holo- type LACM - AHF no. 1255 X14 Figure 12: Terebra hancocki. Hypotype LACM no. 65-23; nucleus st tn st i . { e | 3 s | \—— | x i} 4 i BS ~~ = : 2 Eo & ix cI oO 3 ook Si v =>} 00 iz [o) _ Oo = = Of i nD Bp iz Cc L t=} teYa) S lop) ) Z ov ) > ne a g a > a q fH Vol. 12; No. 3 striations instead of a spiral sculpture of raised cords. Terebra interstincta Hinps, 1844, has a more slanted columella, quadrate aperture, enlarged nodes on subsu- tural band and small nodes posterior to the suture. Tereb- ra dorothyae, new species, is a more slender shell with smaller and sharper nodes and a more twisted columella than T: allyni. This species is named for Mr. Allyn G. Smith of San Francisco, California, in recognition of his work in Mala- cology and for his encouragement of and assistance to workers in this field. Terebra hancocki BRATCHER & BURCH, spec. nov. (Plate 44, Figures 11, 12) Description: Size large; color shiny pale beige back- ground with irregular blotches of reddish brown; whorls moderately convex with convex subsutural band marked by impressed suture and broad, deep subsutural groove; nucleus missing; early sculpture of almost straight axial ribs narrower than interspaces and of 3 rows of spiral grooves which faintly cross ribs; in later sculpture spiral grooves become unevenly spaced and broad, with strap- like raised cords betwen, crossing axial ribs to produce small nodes and give sculpture a file-like appearance; subsutural band has rounded nodes on early whorls, elon- gate nodes on later whorls; body whorl of medium length with lighter stripe and groove at periphery; anterior to periphery spiral grooves continue to cross now obsolete axial ribs with somewhat nodose effect; aperture semi- quadrate; outer lip sturdy, white within; columella white, twisted, broad, with 2 heavy plications; siphonal fasciole heavy, striate, with a sharp posterior keel which continues to posterior plication of columella; anterior canal broad, very twisted; length 75.3mm; diameter 15.3mm; 15 whorls, apex missing. Holotype: LACM -—— AHF Type Collection no. 1255. Type locality: All type material was collected off La Libertad, Ecuador 2°08’ S Lat., 81°00’ W Long. Paratypes: LACM — AHF, Type Collection no. 1256; CAS, Department of Geology, Type Collection no. 13282; SU Conchological Collection no. 9995; SBMNH, Type Collection no. 27143; AMNH no. 155886; USNM no. 678614; ANSP no. 316418; DMNH no. 51367; BM(NH). Other material examined: AMNH 74:75642; AMNH 51:74585 and LACM A875 from the Tres Marias Islands, Mexico; USNM 590706, Shy Collection and Thomas Collection from Manzanillo, Colima, Mexico; AHF 265- THE VELIGER Page 299 35 from Petatlan Bay, Mexico; USNM A5498 from Gulf of Tehuantepec, Mexico; LACM A2777 from Corinto Bay, Nicaragua; AHF 257-34 and 256-34 from Port Cu- lebra, Costa Rica; AHF 940-39 and 941-39 from the Gulf of Dulce, Costa Rica; LACM B-12 from Taboga area, Panama; AHF 239-23 and 413-25 from Port Utria, Colombia; AHF 399-35 from Salango Island, Ecuador. Largest specimen examined: The holotype. Discussion: The colored areas on the pale beige back- ground may be purplish-gray, gold, reddish-brown or a combination of all 3 colors. Though we have examined many specimens of this species, only 1 has been seen with nucleus intact. The nucleus is of 34 slender, slightly con- vex whorls. The first 14 whorls of the nucleus are gray in color and the remaining 2 whorls are light brown. The 2 plications on the columella of Terebra hancocki are the most prominent of any west American species we have examined. Several Panamic species resemble Terebra hancocki in general appearance. Terebra variegata Gray, 1834, is a broader species which does not become as noded or file- like in appearance and has a protoconch of 24 whorls. The more cancellate or noded form of T: glauca Hinps, 1844, has a superficial resemblance, but the latter is a smaller and more slender species with less heavy plications on the columella and a protoconch of 24 whorls. Some of the sculptural variations of T. albocincta CARPENTER, 1857, very closely approach T. hancocki in appearance, but the former is a smaller and more slender species with a different color pattern, less prominent columellar plica- tions and different sculpture in the early whorls. Terebra dislocata (Say, 1822), which occurs on both coasts of the Americas, is also a smaller and more slender species with less heavy columellar plications. This species is named in honor of Captain G. Allan Hancock for his contributions to Malacology during the Hancock Pacific Expeditions. ACKNOWLEDGMENT We wish to acknowledge with gratitude the assistance generously given us by a number of individuals and insti- tutions by having made comparison specimens available, providing locality information and other data and for locating or making available needed reference materials. In addition to Mr. and Mrs. Carl Shy, Mrs. Dorothy Brown, Mrs. Jeanne Frisbey and Mr. Lawrence Thomas, whose collections have been cited here, we wish to express our appreciation for the loan of pertinent comparison Page 300 specimens to Mr. and Mrs. Ben Purdy of San Diego, California, and Mr. and Mrs. John Q. Burch of Seal Beach, California. A number of institutional collections were also made available, providing large numbers of comparison speci- mens with accurate collection and locality information. We wish to express our appreciation to Dr. John S. Garth of the Allan Hancock Foundation, Dr. William K. Emerson and Mr. William Old, Jr., of the American Mu- seum of Natural History, Dr. Leo G. Hertlein of the California Academy of Sciences, Dr. James H. McLean and Mr. Gale Sphon of the Los Angeles County Museum of Natural History, Dr. Copeland McClintock and Mrs. Diane Ryerson of the Peabody Museum of Yale Univer- sity, and Drs. Harald Rehder and Joseph Rosewater of the United States National Museum for the loan of speci- mens from their respective institutions. We are especially appreciative of the patient assistance given by Mrs. Dorothy Halmos and Miss Mary Ellen Pippin of the Hancock Library of the University of South- ern California and of Mrs. Dorothy Martin, Miss Betty Begun and Mrs. Azile Kokos of the Los Angeles County Museum Library for locating much of the reference mate- rial needed for this study. Other reference material has . generously been made available by Dr. S. Stillman Berry and Mr. and Mrs. John Q. Burch from their personal libraries. LITERATURE CITED ApaMs, ARTHUR & Lovett Aucustus REEVE 1848-1850. The zoology of the voyage of H. M.S. Samarang, under the command of Captain Sir Edward Belcher, during the years 1843-1846. Mollusca, prt. 2: 25 - 44; plts. 10 - 17. London CampBELL, G. Bruce 1951. Four new Panamic gastropods. 25 - 28; plt. 5 The Veliger 4 (1): (1 July 1961) THE VELIGER Vol. 12; No. 3 1964. New terebrid species from the eastern Pacific (Mollusca: Gastropoda). The Veliger 6 (3): 132 - 138; plt. 17 (1 January 1964) CarPENTER, Puitip PEARSALL 1857. Catalogue of the collection of Mazatlan shells in the British Museum collected by Frederick Reigen. London: Brit- ish Mus. i - vit+ix - vxi+552 pp. (with preface by J. E. Gray) (post June 1857). [Warrington ed. with author's preface, pp. V - viii, publ. simultaneously for distribution with duplicate col- lections] Conrab, TrmotHy AsBBotTr 1848. Tertiary fossil shells. Proc. Acad. Nat. Sci. Philadel- phia 3 (for 1846 and 1847): 19-27; plts. 1, 2 Gray, Joun Epwarp 1834. [Untitled. Terebra] Proc. Zool. Soc. London, prt. 2: 50 - 63 [pp. 50 - 56 — 26 Sept.; 57 - 63 — Nov. 1834] Hinps, RicHarp BrinsLey 1844. Descriptions of new shells collected during the voyage of the Sulphur, and in Mr. Cuming’s late visit to the Philip- pines. Proc. Zool. Soc. London for 1843, pt. 11: 149 - 168 (June 1844) Li, Coty CHANG 1930. The Miocene and Recent Mollusca of Panama Bay. Bull. Geol. Soc. China 9 (3): 249-296; plts. 1-8; 1 map (October 1930) Pitspry, Henry Aucustus « Hersert N. Lowe 1932. | West Mexican and Central American mollusks collec- ted by H. N. Lowe 1929-31. Proc. Acad. Nat. Sci. Philadel- phia 84: 33 - 144; 6 figs.; plts. 1-17; 2 photographs (21 May 1932) Say, THoMAS : 1822. An account of some marine shells of the United States. Journ. Acad. Nat. Sci. Phila. 2 (2): 221-248 (June 1822) ScHWENGEL, JEAN SANDERSON 1940. [Untitled]. The Nautilus 53 (3): plt. 12 (Jan. ’40) 1942. | New Florida marine mollusks. The Nautilus 56 (2): 62 - 66; pit. 6 (October 1942) Smrrn, Epcar ALBERT 1873. | Remarks on a few species belonging to the family Tere- bridae, and descriptions of several new forms in the collection of the British Museum. Ann. Mag. Nat. Hist., (ser. 4), 1879. Mollusca from Japan. Proc. Zool. Soc. London 11: 262 - 271 (Terebra: pp. 183 - 186; plt. 19) (August 1879) Vol. 12; No. 3 THE VELIGER Page 301 Observations on the Anatomy and Biology of Two California Vermetid Gastropods BY MICHAEL G. HADFIELD Pacific Biomedical Research Center, University of Hawaii, Honolulu, Hawaii 96822 (Plate 45; 4 Text figures) INTRODUCTION THE MARINE GASTROPODS included in the family Vermeti- dae form a morphologically distinct group characterized by shells which are uncoiled and cemented to a substra- tum. This feature is shared with the prosobranchs of the family Siliquariidae to which the Vermetidae are closely related. The siliquariids are distinct from the vermetids in having a long slit through the mantle wall and shell on the right side beneath the rectum, and in retaining a spiral corkscrew shape in their shell (Morton, 1951, 1955). Both families are placed in the mesogastropod super-family Cerithiacea, which contains, in addition, such well known temperate forms as Turritella, Cerithium, and Bittium (THIELE, 1931; Morton, 1958). There have been very few comprehensive treatments of the vermetids. Between 1900 and 1940 only 3 papers appeared which were devoted to aspects of the biology of vermetids (though taxonomic citations occur in other works) ; these were BortTcerR (1930), Yonce (1932), and Yonce & ItEs (1939). BoETTGER was concerned with nutritional physiology, while YoncE & ILES compared cer- tain points of the anatomy of Serpulorbis gigas (Brvona- Bernarpi, 1832) of the Mediterranean with that of Dendropoma maximum (SoweErsy, 1835) from Australia. Since 1940 the vermetids have received considerable attention at the hands of Professor J. E. Morton of Auck- land (1950; 1951, a, b, c; 1955; 1965). It was Morton who separated the vermetids and siliquariids into two taxa (1951) and attempted to establish sound anatomical criteria for the generic groupings within the Vermetidae (1965). Keen (1961) had already performed the ex- ceedingly difficult task of reducing the more than 45 nominal genera to a realistic 5. Morton has been particularly interested in mechanisms of feeding in the vermetids and in the evolution of the group. While he did have access to preserved material of Petaloconchus montereyensis (Dati, 1919) and Ser- pulorbis squamigerus (CARPENTER, 1857), the species studied here, Morton’s discussion of function in these species is based upon inferences from anatomy. Morton’s descriptions of the digestive system are complete, but he has only briefly described the reproductive system and has omitted reference to the nervous system altogether. Compared with that for most other large prosobranch families, our knowledge of the biology of living ver- metids is slight, and concerns only a small number of spe- cies. Of some 250 nominal species of Vermetidae, only 8 or 9 have been examined alive. Morton (1965) dis- cussed most of the literature on this topic and the only subsequent work is a study by Urret Sarriet (1966) on the “vermetid formations” of the Israeli shore of the Mediterranean Sea in which he presents an interesting description of the geological effects of vermetid intertidal zonation. The following discussion of anatomy and biology of the two California vermetid species, Petaloconchus monterey- ensis and Serpulorbis squamigerus, provides a background for detailed information on reproduction to be discussed in subsequent papers, and presents certain new information on systems in these species for which published accounts are lacking. MATERIALS ann METHODS Serpulorbis squamigerus (CARPENTER, 1857) While a few specimens of this species were collected on the Monterey Peninsula, most of the animals used were taken at Malibu and Newport Beach, California. For the sake of comparison, animals were also collected at San Diego, La Jolla, Newport Bay, and Santa Barbara, Cali- Page 302 THE VELIGER Vol. 12; No. 3 fornia. The animals collected at these localities, though differing in their habitats, were all clearly of one species. Petaloconchus montereyensis (DAL, 1919) Most of the animals utilized in this study were collected from two restricted populations on Mussel Point adjacent to the Hopkins Marine Station, Pacific Grove, Califor- nia. Other specimens, taken for comparative purposes, were collected at Point Pinos and Pescadero Point, on the Monterey Peninsula. Both species were kept for periods of up to more than one year at 12° to 16° C in aquaria at Hopkins Marine Station. The aquaria were provided with a continuous flow of fresh seawater pumped from Monterey Bay. While the animals survived well in the laboratory, they usually ceased reproductivity within one to two weeks after their confinement in aquaria. Except in feeding experiments, no attempt was made to provide food for the animals other than the plankton which passes through the filters at the seawater intake. The living animals were examined both grossly and microscopically in small dishes of seawater under a dis- secting microscope. It was necessary to anesthetize ani- mals before removing them from their shells for obser- vation and dissection. Anesthetization was brought about by immersing the animals in an aqueous solution of mag- nesium chloride isotonic to sea water (75 g per 1 1 of tap water). The animals were usually completely immobilized by this treatment in 3 to 4 hours. ANATOMY Serpulorbis squamigerus and Petaloconchus monterey- ensis, like all the members of the family Vermetidae, con- struct calcareous shells which are securely cemented to a substratum. While the configuration of these shells (see KEEN, 1961) is unlike that of most gastropods, the animals themselves possess fairly typical gastropodan bodies which may be divided into head-foot, pallial, and abdominal regions (Text figure 1; Plate 45, Figures 3, 4). The foot is cylindrical, naked in Serpulorbis but covered by an operculum in Petaloconchus (Text figure 4A; Plate 45, Figure 2). The muscular mass of the foot is directly connected with the well-developed columellar muscle which runs up the ventral side of the pallial region. Since the major portion of the adult foot bears the operculum in most vermetids, this part of the foot is considered to correspond to the metapodium of the foot of the vermetid juvenile and other free-living snails (see Morton, 1955). The mesopodium is represented in the adult vermetid by a small shield-shaped pad of tissue below the mouth, Os Ct Figure 1 Female Serpulorbis squamigerus with the mantle wall opened along the dorsal mid-line and deflected to show pallial structures. Ct - ctenidium; K - kidney; G - ovary; Os - osphradium ; POd - pallial oviduct R - rectum V - ventricle while the orifices of the large pedal mucus glands and the pedal tentacles together represent the propodium. The two pedal tentacles, which originate in depressions ventro- lateral to the mouth, are very extensible, and each has a groove running up its mesial margin. Vol. 12; No. 3 THE VELIGER Page 303 The snout, with the horizontal slit-shaped mouth at its terminus, is directly above the propodium. Slightly poste- rior to the snout, on each side of the dorsal surface of the head, a cephalic tentacle arises; each bears an eye on its posterior lateral margin. The head narrows behind the eyes to form a “neck” region at the entrance to the mantle cavity. In life, the head and foot of both species are mostly black with small amounts of orange pigmentation around the foot and the lateral ridges of the head. However, the color pattern of Petaloconchus montereyensis is quite vari- able, and in some populations the predominant ground color of the head is brownish-orange. The thickened edge of the mantle which encircles the head and foot is brown- ish-orange with flecks of dense white. The mantle cavity is relatively deep, extending for 50% of the total length of the animal in Serpulorbis and 40% in Petaloconchus. The roof of the cavity displays the only strongly sexually dimorphic character in Serpulorbis. Here, in reproductively active females, a long slit in the median dorsal mantle wall provides contact between the mantle cavity and the shell over the pallial region (Plate 45, Figure 4). The egg capsules are attached to the ex- posed shell in this region. No such slit occurs in the females of Petaloconchus. A ridge of muscular tissue arises on the posterior dor- sal surface of the head and runs posteriorly, dividing the ventral portion of the mantle cavity into right and left halves (Text figure 2A). The ridge flattens out only in the most posterior portion of the pallial cavity. The organs lying within the mantle cavity are those of a typical prosobranch mesogastropod (Text figure 1). They in- clude an elongate ctenidium on the left wall composed of triangular lamellae, a long osphradium lying beneath the gill, a hypobranchial gland on the mantle cavity roof, the rectum on the right dorsal portion of the roof, pallial re- productive structures in the posterior right ventral region, Figure 2 (adjacent column —>) Diagrammatic cross-sections through Serpulorbis squamigerus A: through the anterior portion of the mantle cavity of a female; B: through the posterior portion of the mantle cavity; C: through the abdominal region of a sexually mature male. DD - digestive gland duct; COL - columellar muscle; Cp-capsule gland; Ct-ctenidium; Dg - digestive gland; E -esophagus; G - gonad; Hy - hypobranchial gland; K - glandular portion of kidney; MC - mantle cavity; MG - pedal mucous gland; Pc - pericardium R - rectum N- right pleuro-visceral nervous connective; VD - vas deferens Page 304 and the kidney orifice in the posterior wall (Text figures 1, 2A, 2B). The kidney consists of a large sac placed directly behind the mantle cavity on the right half of the body, and a large amount of excretory tissue which extends out into the posterior roof of the mantle cavity (Text figure 2B). On the left side the pericardium extends dor- sally and anteriorly over the more posterior part of the pallial cavity (Text figure 2B). It contains the large ven- tricle and the smaller auricle of the heart. The mouth opens into a buccal cavity surrounded by a massive buccal muscular apparatus which manipulates the jaws and radula. The buccal cavity opens dorsally into the esophagus which is provided with a pair of salivary glands borne on the posterior dorsal surface of the buccal mass. The-esophagus is very long and runs from the buccal mass directly posteriorly beneath the mantle cavity, the heart, and the kidney, to the stomach. The large pedal mucous glands lie parallel to the esophagus along half its length (Text figure 2A). Behind the heart and kidney lies the abdominal region of the body. The anterior portion of this region contains several coils of the intestine, the stomach, and the style sac. Behind the stomach is a tail-like region of variable length which contains the digestive gland on the left and | the gonad on the right (Text figure 2C.). The major chan- nel of the digestive gland is ventral in position, as are the major blood lacunae, the abdominal nervous extensions, and the gonoduct. The elongate columellar muscle originates in the foot, forms the ventral portion of the body mass in the pallial region, emerges from the body at the level of the posterior end of the pallial cavity, and continues backward as a long free strap to its insertion far back inside the shell. The nervous system of vermetid gastropods has been examined only in Vermetus triqueter (BIvoNA-BERNARDI, 1832) by Lacaze-Dutuirrs, 1860. The ganglia and ma- jor nerves of Serpulorbis squamigerus are easily examined after anesthetization and formalin fixation of the animal. The details of the nervous system of this species are pre- sented in Text figure 3. All major ganglia are paired, a condition generally accepted as primitive in gastropods (FRETTER & GRAHAM, 1962), and all except the parietal (or supra- and sub-esophageal) ganglia lie in their ex- pected complementary bilateral positions. The sub-eso- phageal ganglion is located next to the posterior face of the left pleural ganglion. The supra-esophageal ganglion is well removed from the circumesophageal nervous com- plex; it lies more posteriorly and to the left, near the osphradium. The cerebral ganglia lie on the esophagus posterior to the buccal mass. They are provided with thick connectives to the pleural and pedal ganglia and are linked across the THE VELIGER Vol. 12; No. 3 esophagus by a thick cerebral commissure. Three large nerve trunks leave each cerebral ganglion anteriorly. The most lateral of these bifurcates, one nerve going to the region of the mouth and the other recurving and pene- trating the buccal mass to connect with the buccal gang- lion on that side. The buccal ganglia lie on the posterior dorsal face of the buccal mass, and innervate the complex musculature of the buccal apparatus. The middle nerve arising from each cerebral ganglion runs to the lips and the innermost nerve innervates the eye and cephalic tentacle on its side. The pleural ganglia lie ventrally to the cerebral ganglia with which they are connected by thick commissures. A commissure also links each pleural with the pedal ganglion of the same side. The left pleural ganglion is closely associated with the sub-esophageal ganglion. A nerve a- rises from the dorsal face of each pleural ganglion to innervate the neck musculature on each side. From the postero-lateral face of each pleural ganglion a large nerve arises which receives a zygoneuric connection from the pleuro-visceral loop. Proximal to the point of zygoneury, the nerve arising from the left pleural ganglion sends one branch to innervate the mantle edge on the same side; distal to the zygoneuric connection from the supra-eso- phageal ganglion, the nerve runs on to innervate the os- phradium and ctenidium. The corresponding nerve orig- inating from the right pleural ganglion receives the zygo- neuric connection from the sub-esophageal ganglion and extends toward the right side; it soon bifurcates, the larger anterior branch innervating the mantle edge, while the smaller branch runs posteriorly to the mantle wall in the region of the anus. A third large nerve, the left segment of the pleuro- visceral loop, arises from the right pleural ganglion, runs diagonally posteriorly dorsal to the esophagus, and enters the supra-esophageal ganglion on the left side. From this ganglion arise the left zygoneury, a large osphradiobran- chial nerve, and the remaining posteriorly directed left part of the pleuro-visceral loop. The right segment of the pleuro-visceral loop originates anteriorly from the sub- esophageal ganglion and runs diagonally posteriorly, beneath the esophagus. The pedal ganglia are connected with each other by a sub-esophageal commissure and with the cerebral and pleural ganglia on their respective sides by thick connec- tives. From the anterior face of each pedal ganglion 3 large nerves and one slender nerve arise. The latter, which has a slightly dorsal origin, and the most lateral of the thicker nerves innervate the muscles of the basal wall of the head. The middle of the larger nerves arising from each pedal ganglion runs directly anteriorly to innervate Vol. 12; No. 3 Figure 3 The nervous system of Serpulorbis squamigerus A: lateral view of the cerebral complex B: dorsal view, pleuro-visceral connectives foreshortened BG - buccal ganglion COG - ctenidial-osphradial ganglion; PIG - pleural ganglion; SbG - sug-esophageal ganglion; SpG - supra-esophageal ganglion; VGL - left visceral ganglion; VGR - right visceral ganglion; E - esophagus; cbc - cerebro-buccal connective; cn - cardiac nerve; con - ctenidial-osphradial nerves; _ cpc - cerebro-pleural connective; 1- labial nerves; m- mantle nerves; op - optic nerve; pe - pedal commissure; pd - pedal nerve; plpc - pleuro-pedal connective; pt- pedal tentacle nerve; pvcl - left pleuro-visceral connective; pver - right pleuro-visceral connective; t-tentacular nerve; vis - visceral nerves; zl- left zygoneury; zr - right zygoneury CG - cerebral ganglion PG - pedal ganglion; ESV EIGER Page 305 the foot. The medial large nerve on each side innervates the respective pedal tentacle. The remaining portion of the nervous system consists of the posterior segment of the pleuro-visceral loop and its branches. The right side of this loop runs beneath the mantle cavity and extends small branches to the mantle wall and floor. It passes beneath the posterior wall of the mantle cavity (adjoining the anterior wall of the kidney sac) and continues posteriorly in close association with the gonoduct. Below the kidney, where the coelomic gono- duct turns dorsally to join the pallial gonoduct, the right pleuro-visceral connective branches, one branch continu- ing posteriorly, the other running dorsally in the kidney wall to the right visceral ganglion which lies in the ante- rior kidney wall directly above the origin of the pallial gonoduct. From the right visceral ganglion two nerves arise. One runs to the pericardial region; the other, forming the posterior portion of the pleuro-visceral loop, extends to the left to join the left visceral ganglion near the posterior end of the ctenidium. From the left visceral ganglion a nerve arises which runs posteriorly along the ventral surface of the animal into the abdominal region. A similar nerve, the continuation of the right pleuro-vis- ceral connective, runs into the abdomen on the right ventral side of the animal in conjunction with the gono- duct; it appears to innervate the gonad. The pattern of the nervous system shown here is typical for members of the super-family Cerithiacea (see Bouvier, 1887, for numerous other examples). The major variations here are the retention of unfused visceral ganglia and the absence of statocysts which occur on the pedal ganglia of most other gastropods. Considering the sessile habit of the vermetids, the absence of statocysts is not surprising. The nervous system of Serpulorbis squamigerus is nearly identical to that shown for Vermetus triqueter by LacaZzE- Dutuiers (1860), except that S. squamigerus has a left visceral ganglion while V. triqueter does not. BIOLOGY Serpulorbis squamigerus MacGinitie & MacGinitie (1968) discussed the habitat, the gregarious nature, and the mucous-net mode of food collecting of these snails. Further details from the present study are added below. The mucous nets are a product of the extensive paired pedal mucous glands. These glands are capable of secret- ing a net as large as 50 cm? in 3 to 4 minutes. The mucus flows out of the median aperture between the bases of the pedal tentacles and is carried distally by ciliary cur- Page 306 THE VELIGER Vol. 12; No. 3 rents in the grooves on the pedal tentacles. The pedal tentacles thus spread the single string of mucus issuing from the aperture of the gland into a triangular sheet (Plate 45, Figure 1). Some hardening of the mucus ap- parently occurs on contact with seawater. The density of the mucus is close to that of seawater since the net is buoyed upward by very slight turbulence or by only a few tiny trapped bubbles. The mucous net remains suspended in the water for 10 to 30 minutes and is then retrieved by the action of the radula and jaws. The radula is extended far out of the widely-opened mouth; it grasps the mucous net and pulls it a short distance down and into the mouth. The jaws then close on the mucus, holding it during swallowing and disengagement of the radula. The esophagus of Serpul- orbis squamigerus is very long and extensible, a modifica- tion which provides a large storage area for the rapidly ingested mucous net before its slower passage into the stomach. In laboratory aquaria individuals of Serpulorbis squa- migerus may be stimulated to produce mucous nets by either strong water currents or agitation of the water. The addition of dried and ground algae or dried animal mat- ter (commercial pet fish food) to unagitated water in the aquaria did not elicit feeding, nor did the addition of live copepods (Tigriopus californicus BAKER, 1912). It would thus appear that the usual stimulus for feeding in this species is water turbulence (the incoming tide?) and not the presence of food, as BoETTcER (1930) found to be the case for S. gigas. Individuals of Serpulorbis squamigerus are predomi- nantly gregarious, but not exclusively so. They are often found widely separated from one another on floats in southern California yacht basins. In these instances the “communal mess table” emphasized by Morton (1965) does not occur, but the animals are apparently successful in their enforced solitary feeding, for isolated individuals are often of much greater size than aggregated ones. While the mucous-net method is the predominant meth- od of feeding in Serpulorbis squamigerus it may not be the only one; examination of the ciliary currents of the mantle cavity clearly shows that material filtered out of seawater by the gills is passed to the oral region. Actual ingestion of this material was not observed. Just what constitutes the major food of Serpulorbis in the field is still uncertain. Laboratory aquaria undoubtedly present an anomalous situation. However, examination of nets extended in the aquaria shows them invariably to contain numerous diatoms, skeletons of small crustaceans, and unidentifiable debris. In paraffin sections through the stomach region of S. sqguamigerus taken in the field I have seen diatoms and occasional small crustaceans and worms. Whether or not the snails are capable of digesting animal matter remains open to investigation. The presence of a crystalline style would appear to argue against such a possibility (YonceE, 1930, 1932). MacGiniTigE & MacGinitie (1968) state that Serpul- orbis squamigerus is preyed upon by the carnivorous pro- sobranchs Ceratostoma foliatum (GmeEtIn, 1791) and Shaskyus festivus (Hinps, 1844). In the present study no predators have been seen, but the presence of trematode cercariae in the abdomen of S. squamigerus has been noted frequently. These cercariae appear to feed exclusive- ly on the gonad of the snail and may cause nearly total castration. An occasional commensal of S$. squamigerus is a pinnotherid crab, tentatively identified as Opisthopus transversus RATHBUN, 1893. These crabs occur in the mantle cavity, and when removed from one snail have been observed to re-enter the mantle cavity of another host quite readily. The snails exhibit little response to the ent- rance of the crab. Curiously, this association has only been noted in snails collected from the Malibu region of Cali- fornia and never from animals collected to the north or south of this area. The pinnotherids were noted in indi- viduals of S. squamigerus collected in March and May 1966. As might be expected, the numerous spaces between the tubes of large masses of Serpulorbis provide refuge for great numbers of other invertebrates. Among these are calyptraeid gastropods, nemerteans, sipunculids, poly- chaetes, and the ubiquitous nematodes. The tips of the vermetid tubes are frequently encrusted by bryozoans, sponges, and compound ascidians. Explanation of Plate 45 Figure 1: Serpulorbis squamigerus feeding (1) Figure 2: Petaloconchus montereyensis: mass of living individuals (X 2.5) Figure 3: Preserved specimen of Serpulorbis squamigerus seen from the right side (X 1.5) Figure 4: Preserved specimens of Serpulorbis squamigerus, male and female, seen in dorsal view (X 1.5) C - columellar muscle; F - foot; H - head; MM - mantle margin; Mn - mucous net; PS - pallial slit of female; Pt - pedal tentacle; 1, 2, and 3 represent gross body regions: 1, mantle cavity; 2, region of heart, kidney and stomach; 3, region of digestive gland and gonad THE VELIGER, Vol. 12, No. 3 [HapFIELp] Plate 45 Figure 3 Figure 4 Vol. 12; No. 3 THE VELIGER Page 307 Just how dense the populations of Serpulorbis squami- gerus may be in some localities was illustrated by PEQUE- GNAT (1964) who reported concentrations of this species of 650 per m’. The greatest concentrations of S. squami- gerus seen in the present study are on a small sandstone outcropping adjacent to the beach at the Kerkhoff Marine Laboratory, Newport Bay, California. The stone is sur- rounded by muddy sand which limits the spread of S. squamigerus, but nearly every square inch of exposed rock is covered by them. Sponges and bryozoans are also abun- dant on and around the vermetid tubes. KEEN (1961, p. 203) gives the range for Serpulorbis squamigerus “from Monterey, California, to southern Baja California.” This is undoubtedly more accurate than the listing by R. T: Appott (1954), “Forrester Island, Alaska to Peru,” since many of the reports on which ABBorTtT’s range is based are by authors who confused S. squamigerus with other vermetids, some not even of this genus (OLD- ROYD, 1924, describes “Aletes squamigerus” as a species bearing an operculum!). Nowhere north of Point Con- ception, California have large numbers of S. squamigerus been seen, and on the Monterey Peninsula they are rare. Within the range given by KEEN (1961), the vertical distribution of Serpulorbis squamigerus is poorly known. Studies on the biota around sewer outfalls and off-shore oil wells (TURNER et al, 1962, 1965a, 1965b) include records of S. squamigerus from the intertidal zone to depths of 80 feet. A more reliable maximum depth is prob- ably 50 feet, since the 80 foot record was of a single specimen (a shell?) found on a sandy bottom, an unlikely habitat for a vermetid. In the area studied by PEQUEGNAT (1964), which consisted of two sandstone reefs offshore from Corona Del Mar, California, S$. squamigerus was noted to occur on the reef tops, average depth 11 m, in areas of greatest turbulence. Petaloconchus montereyensis Petaloconchus montereyensis is known only from concho- logical faunal lists and Morton’s (1965) partial descrip- tion of the animal based on preserved material. Specimens used in this study were collected from the type locality, “Monterey, California” (Dat, 1919), and the surround- ing coast. Morton (op. cit.) has suggested that Petaloconchus montereyensis should be capable of both ciliary filter feeding and feeding with mucous nets (his judgments were based on relative size of the ctenidium and pedal mucous glands). This is indeed the case. The ciliary and glandular tracts of the gill and mantle walls carry par- ticles from the gills forward over the mantle floor to the mesopodial pad in front of the mouth where they are mixed with mucus and then ingested. However, the pre- dominant method of feeding is by means of mucous nets as in Serpulorbis squamigerus. The nets of Petaloconchus are fragile, and in aggregates of these snails they are fused in a thin veil which overlies a whole portion of the colony. The nets are so thin as to be barely discernible unless they are laden with detritus particles. The nets are produced and retrieved in a manner precisely like that described for Serpulorbis. Petaloconchus montereyensis, while predominantly gre- garious (Plate 45, Figure 2), is represented occasionally by isolated individuals. As these individuals have been found in reproductive condition and equal in size to in- dividuals occurring in gregarious masses, it appears there is no great dependence on communal feeding nets. Petaloconchus montereyensis serves as host to parasites and commensals. A high rate of infection by trematode cercariae occurs in populations at Mussel Point, Pacific Grove, California. The cercariae live on the tissue of the gonad and may effectively castrate the host. Petaloconchus is also the host for a pyramidellid snail of the genus Odo- stomia (Chrysallida). This small parasite has been observed frequently on masses of Petaloconchus montereyensis tubes. Odostomia feeds by creeping up to the mouth of a ver- metid tube and piercing the fleshy edge of the mantle tissue with its proboscis. Amongst the masses of Petaloconchus tubes numerous other small invertebrates find refuge. Phascolosoma agas- sizit KEFERSTEIN, 1866 is common here; a small clam, Kellia, occurs frequently, and many other marine snails are encountered in this habitat. An almost invariable asso- ciate of P montereyensis is the polychaete Dodecaceria fistulicola Exuters, 1901. The calcareous tubes of this worm are generally found in a band above the zone of Petaloconchus ; no clear-cut demarcation between the pop- ulations of the two species exists, and often there is a horizontal band a few centimeters wide where their tubes are intermixed. Finally, a small ostracod is often found crawling in and around the tubes of P montereyensis. It lays its small, lens-shaped egg capsules on the center of the operculum of Petaloconchus. Petaloconchus montereyensis may be unique among the Gastropoda in its habit of periodically producing a new operculum and moulting the old one. While marine snails have been found capable of regenerating the operculum (Hanxo, 1913), I know of no other instance where total operculum replacement represents a regular activity on the part of a snail. In Petaloconchus montereyensis gross appearances suggest that most of the pedal surface has the capacity to produce opercular material. The opercu- lum of a fully grown animal is only slightly smaller in diameter than the tube aperture. It is a flat plate with a central nucleus and bears a high, raised flange which spirals outward from the nucleus in a counter-clockwise Page 308 THE VELIGER Vol. 12; No. 3 Figure 4 The operculum of Petaloconchus montereyensis A: the complete operculum B and C: two successive stages in operculum replacement Op - operculum direction (Text figure 4). The fully developed operculum has a flange which completes three whorls from the nuc- leus to the outer edge. Marginally the thin outermost whorl of the flange overlaps the lateral edges of the foot. Small and intermediate sized individuals of Petalocon- chus montereyensis are often found in the process of re- placing a perfectly formed operculum with one only slight- ly larger. This observation suggests that opercular replace- ment (rather than simple marginal increment) repre- sents a natural part of growth in this species. After the individuals have achieved full growth, the stimulus for formation of a new operculum may be related to deterior- ation of the old one. The worn operculum is ragged and reduced at the edges and along the flanges, and overgrown by a crust of diatoms and even small red or brown algae. The process of replacement is first detectable when the opercular nucleus is displaced to the left on the face of the foot and the right hand edge of the operculum be- comes free from the surface of the foot. On lifting the edge one can observe, lying beneath the old operculum, the small transparent nucleus of a new one. As the new oper- culum grows, increasing in size by additions along the periphery of the spiral, the old operculum becomes pro- gressively freed from the surface of the foot until its only attachment is along the extreme left edge. In this stage the animals often appear to have two functioning oper- cula. Finally the snail sheds its old operculum by repeat- edly hooking its edge over the lip of the shell and then retracting the foot until the operculum is free. New oper- cula are always recognizable by their smooth glossy sur- faces, their transparency, and their lack of encrustation (Text figure 4). While Petaloconchus montereyensis is known only from the Monterey Peninsula, California, I have collected animals from San Juan Island, Washington which are, in all external aspects, identical to those from Monterey. Its vertical distribution has never been studied. The species is most abundant slightly below the zero tide level in areas of heavy, but broken wave turbulence. Shells of Petalo- conchus have been collected by Dr. J. H. McLean from as deep as 90 feet in the Carmel Submarine Canyon, but I hesitate to assign these to the species P montereyensis on the basis of the presently available material. In certain localities (Mussel Point, Pescadero Point, and Mission Point, Monterey County, California) aggregates of Petaloconchus montereyensis may completely cover rock surfaces for areas of two or more square meters. I have attempted to obtain a rough approximation of the density of Petaloconchus in such masses by breaking off a small piece of a large mass, decalcifying the whole piece and counting all the animals in it regardless of size. The figure obtained is 12 Petaloconchus per square centimeter, about half of which are large enough to be sexually mature. An extrapolation of this figure suggests an aggre- gation of Petaloconchus covering 2 m’ might easily contain over 200000 snails. ACKNOWLEDGMENTS I am indebted to Dr. Donald P. Abbott for numerous en- lightening discussions and his editorial helping hand. Dr. Myra Keen kindly gave of her time and knowledge in discussions of the taxonomy of the Vermetidae. Mrs. Dana B. Pearse prepared the line drawings. This work was supported by PHS grant number 5-F1- GM-18,937. Vol. 12; No. 3 LITERATURE CITED AxsBoTT, ROBERT TUCKER 1954. American seashells. Princeton, New Jersey, D. van Nostrand Co., Inc.; xiv+541 pp.; 100 text figs.; 40 plts. BoETTGER, CAEsAR R. 1930. Studien zur Physiologie der Nahrungsaufnahme festge- wachsener Schnecken. Die Ermahrung der Wurmschnecke Vermetus. Biol. Zentralbl. 50: 581 - 598 Bouvier, EucENnE Louis 1887. | Systéme nerveux, morphologie générale et classification des gastéropodes prosobranches. Ann. Sci. Nat. (Fac. Sci., Paris), ser. 7; 3: 1-510 Dai, WILLIAM HEALEY 1919. | New shells from the northwest coast. Soc. Washington 32: 249 - 252 FRETTER, VERA, & ALASTAIR GRAHAM 1962. British prosobranch molluscs, their functional anatomy and ecology. London, Ray Soc. xvi + 755 pp.; 316 figs. Hanko, BELA 1913. Uber die Regeneration des Operkulums bei Murex brandaris. Arch. Entw. Mech. Org. 35: 740 - 747 Hoimes, SAMUEL JACKSON 1900. The early cleavage and formation of the mesoderm of Serpulorbis squamigerus CARPENTER. Biol. Bull. 1: 115-121 Keen, A, Myra 1961. A proposed reclassification of the gastropod family Vermetidae. Bull. Brit. Mus. (Nat. Hist.) Zool. 7 (3): 183 - 213; plts. 53-54; 33 text figs. (February 1961) LacazE-Dutuiers, FELIX Jos—EpH HENRI DE 1860. Mémoire sur l’anatomie et l’embryogénie des vermets (Vermetus triqueter et V. semisurrectus Putt.) Ann. Sci. Nat., ser. 4, Zool. 13: 209 - 296 MacGiniTlE, Grorce Esper & Nettie MacGInITIE 1968. Natural history of marine animals. 2° ed. xii+523 pp.; 286 text figs. McGraw-Hill Book Co., New York Morton, JoHN Epwarp 1950. Feeding mechanisms in the Vermetidae (Order Meso- gastropoda) . Nature 165: 923 - 924 1951. ‘The structure and adaptations of the New Zealand Ver- metidae. Parts I - III. Trans. Proc. Roy. Soc. New Zealand 79: 1-51 1955. The evolution of vermetid gastropods. 9; 3-15 Proc. Biol. Pacif. Sci. THE VELIGER Page 309 Morton, Joun Epwarp 1958. Mollusca. Hutchinson Univ. Libr., London, 232 pp. 1965. Form and function in the evolution of the Vermetidae. Bull. Brit. Mus. (Nat. Hist.), Zool. 11: 585 - 630 Oxproyp, Ipa SHEPARD 1924. Marine shells of Puget Sound and vicinity. Publ. Puget Sound Biol. Sta. 4: 1 - 272 PEguecnaT, WiLus E. 1964. The epifauna of a California siltstone reef. 45: 272 - 283 SAFRIEL, URIEL 1966. Recent vermetid formation on the Mediterranean shore Ecology of Israel. Proc. Malacol. Soc. London 37: 27 - 34 SALENSKY, VLADIMIR 1887. Etudes sur le développement du vermet. Arch. Biol. 6: 655 - 759 THIELE, JOHANNES 1931-1935. Handbuch der systematischen Weichtierkunde. Jena, pp. 1- 1154; 893 text figs. Turner, Cuarzes H., J.G. Cariiste & Earu E. EBert 1962. Offshore oil drilling, its effect upon the marine environ- ment. Final report to Western Oil and Gas Assoc. under terms of the Coop. Agreement between the Assoc. and the Calif. Dept. of Fish and Game: 53 pp. (mimeographed) Turner, Cuares H., Earu E. Esert & RoBertT R. Given 1965a. Survey of the marine environment offshore of San Elijo Lagoon, San Diego County. Calif. Fish and Game 51: 81-112 1956b. The marine environment in the vicinity of the Orange County Sanitation District’s ocean outfall. Reprt. to Santa Ana River Basin Regional Water Pollution Control Board, no. 8, by Calif. Fish and Game Dept. 11 pp. (mimeographed) YonGE, CHARLES MaurIcE 1930. The crystalline style of the molluscs and a carnivorous habit cannot normally coexist. Nature, 125: 444 - 445 1932. Notes on feeding and digestion in Pterocera and Ver- metus, with a discussion on the occurrence of the crystalline style in the Gastropoda. Sci. Reprt. Grt. Barr. Rf. Exped. [Brit. Mus. (Nat. Hist.)] 1: 259 - 281 YonceE, Cuarvtes Maurice & E. J. ILEs 1939. On the mantle cavity, pedal gland, and evolution of mucous feeding in the Vermetidae. Ann. Mag. Nat. Hist Ser. 11, 3: 536 - 556 Page 310 THE VELIGER Vol. 12; No. 3 New Species of Panamic Gastropods BY JAMES H. McLEAN Los Angeles County Museum of Natural History goo Exposition Boulevard, Los Angeles, California 90007 (Plate 46) DurING RECENT YEARS Collecting of mollusks in the Pan- amic Province has greatly increased, due chiefly to the interest generated by the appearance in 1958 of “Seashells of Tropical West America” by Dr. Myra Keen. Now that this book will soon appear in a revised edition, I offer descriptions of the following new species. Several of the species are part of the Allan Hancock Foundation collec- tion now on loan to the Los Angeles County Museum of Natural History, several have resulted from field work of the Museum, while others result from the recent collecting _ in the Galapagos Islands by André and Jacqueline DeRoy, of Isla Santa Cruz, Galapagos Islands. Repositories of type material for species described here- in include the following institutions: AHF — Allan Hancock Foundation (on loan to LACM) AMNH_ - American Museum of Natural History, New York CAS — California Academy of Sciences, San Francisco LACM - Los Angeles County Museum of Natural History SDNHM - San Diego Natural History Museum SU — Stanford University, Stanford, California USNM_ - United States National Museum, Washington, D. C. Arene guttata McLran, spec. nov. (Plate 46, Figures 1, 2) Description of Holotype: Shell small for the genus, solid, umbilicate, turbinate, suture deeply channeled; nuclear whorls 1}, smooth, rounded, the nuclear tip not raised; postnuclear whorls 34. Spiral sculpture on the early whorls consisting of 3 carinations that gradually take shape on emerging from the undelimited nuclear whorls. On the body whorl the peripheral carination projects slightly; this is the 3" of the early spiral cords, above are 2 strongly beaded cords, between which arises a less prominent beaded cord, developed only on the final whorl; below the peripheral cord another strong cord projects almost as far. The suture is laid above this cord until the 3" whorl, at which point the suture exposes it; the base of the cord is not exposed by the suture except at the upper edge of the mature lip. Base with 6 promi- nent beaded cords, 2 of which enter the umbilicus. Axial sculpture of fine lamellae over entire surface, beading on the spiral cords produced by the thickening and overlapping of 5 to 8 layers of lamellae in the direction of growth. Aperture circular, nacreous within, a trace of denticles within the outer lip. Lip thickened, spiral cords reflected inward at lip, when seen in basal view. Color whitish, with random dotting of pink on the spiral cords. Operculum multispiral, concave, of about 10 whorls, beaded in a radiating pattern. Height, 4.5 mm, diameter, 5.0 mm. Type Material: Holotype, LACM 1275; 50 paratypes, LACM 1276; 3 paratypes, AMNH 154685; 3 paratypes, CAS 13273; 3 paratypes, SDNHM 51302; 3 paratypes, SU 9986; 3 paratypes, USNM 679554. Additional paratypes are available for distribution to other institutions. Type Locality: Academy Bay, Santa Cruz Island, Gala- pagos Islands, Ecuador, 0°45’ S, 90°20’ W, in tidal pool under rocks. The type lot, consisting of 119 specimens, was collected by Jacqueline DeRoy, 30 May, 1969. Referred Material: AHF bottom sample 432, Tagus Cove, Albemarle (Isabela) Island, 80-100 fathoms, 1 dead specimen, probably of shallow water origin. Al- though the species is evidently abundant at the type locality, its absence in collections made at shore stations by the Hancock Expeditions suggests that its distribution in the Galapagos Islands is highly localized. Vol. 12; No. 3 THE VELIGER Page 311 Discussion: Arene guttata is evidently one of the species of Arene having a consistent color pattern and on this distinction alone may be separated from other eastern Pacific and western Atlantic species known to me. In addition, other eastern Pacific species having the rounded periphery are considerably larger and have more numer- ous spiral cords. The name is taken from the Latin, guttatus, spotted, with reference to its spotted color pattern of pink dots. Arene echinata McLean, spec. nov. (Plate 46, Figures 3, 4) Description of Holotype: Shell large for the genus, sturdy but not massive, rounded-turbinate, umbilicate, suture deeply channeled. Nucleus of 1 whorl, postnuclear whorls 5, spiral sculpture on the early whorls consisting of 3 strong cords with sharply projecting scales. A 4" strong spiral cord emerges above the suture on the penultimate whorl and 2 secondary cords emerge in the channels ad- jacent to the middle primary cord. On the last whorl just behind the lip all cords are of nearly the same size and counting from the suture to umbilicus there are 12 cords, including 2 that spiral deep within the umbilicus. Axial sculpture of fine growth lamellae, about 7 layers occur between each 2 projecting scales on the spiral cords. Aperture circular, nacreous within, outer lip having weak denticles within. Lip mature but not thickened, abruptly dipping downward at the suture. Color pinkish brown, with irregular lighter mottling. Operculum unknown. Height, 8.5 mm, diameter, 8.0 mm. Type Material: Holotype, AMNH 154626; 1 paratype, AMNH 154627; 2 paratypes, LACM 1277. Type Locality: Espinosa Point, Fernandina Island, Gal- apagos Islands, Ecuador, 0°16’ S, 91°27’ W. The type lot of 4 specimens (hermit crab shells) was collected at low tide by Jacqueline DeRoy, 30 January 1968. Two speci- mens were originally forwarded to Dr. William K. Emer- son of the American Museum of Natural History, who kindly granted me permission to describe the species; 2 additional specimens from the same lot were later received from Mrs. DeRoy. Referred Material: AHF bottom sample station 418, Darwin Bay, Tower Island, Galapagos, 17 fathoms, 1 dead specimen. In addition, dead juvenile specimens are represented from AHF bottom sample stations in the Gal- apagos Islands as follows: 438, San Cristobal (Chatham) ; 441, San Salvador (James); and 452, Santa Maria (Charles), at depths ranging from 24 - 65 fathoms. Discussion: Avene echinata, another species endemic to the Galapagos Islands as far as is known, is the largest east- ern Pacific species of the genus. In this species the usual beaded sculpture of Arene is spinose to a greater extent than observed in other species. Mature specimens may live offshore or may eventually prove to be living at low tide. The name is taken from the Latin, echinatus, spiny, prickly, with reference to the characteristic sculpture. Vermicularia frisbeyae McLean, spec. nov. (Plate 46, Figures 5, 6) Description of Holotype (Turritella-stage): Whorls 12, overall slope of shell slightly convex on the sides, nuclear tip lost, first remaining whorl sculptured by 2 strong raised keels that are equally spaced between the sutures; by the 9" whorl the posterior of the 2 keels is diminished in size and prominence; fine spiral threading appears at about the 10" whorl and the posterior of the 2 keels is barely perceptible, the lowermost or peripheral keel re- mains strong at about 4 the distance from the anterior suture. The base is defined by a strongly projecting keel, the summit of which is left exposed by the growing edge of the lip; base nearly flat, sculptured with fine spiral striae; lip thin (broken on holotype), its growth line trace slanting backward, forming a broad sinus slightly above the main carination; inner lip thin, reflected across a narrow umbilicus. Color whitish with brown maculations along the lines of growth on the body whorl and base. Height, 26.8 mm, diameter, 10.8 mm. Description of Adult Stage: Shell having 3 whorls with relaxed coil beyond the Turritella-stage; the first of these whorls in an open spiral, the last 2 with the axis of coiling at a 45° angle. The basal and the peripheral keels remain strong and there are 5 less prominent spiral cords on the outermost side of the whorl; all surfaces bear fine spiral striae. Height, 61.2 mm, maximum diameter of aperture, 11.0 mm. Type Material: Holotype, LACM 1278; 1 paratype, LA CM 1279 (poor condition) ; 1 paratype, USNM 679555; 1 paratype, SU 9988; 2 paratypes, Frisbey collection (1 in poor condition). Type Locality: Off the lighthouse, Manzanillo, Colima, Mexico, 19°03’ N, 104°20’ W, 30 - 40 fathoms. The type lot, consisting of 6 specimens (Turritella-stage), was dredged by Mrs. Jeanne Frisbey of Port Isabel, Texas, February, 1969. Page 312 THE VELIGER Vol. 12; No. 3 Referred Material: AHF 274-34, Tenacatita Bay, Jalisco, Mexico, 50 fathoms, 2 specimens ( Turritella-stage) ; AHF 863-38, Bahia Honda, Panama, 30-50 fathoms, 1 specimen ( Turritella-stage); 4 lots, Donald Shasky collection, Red- lands, California: Gulf of Tehuantepec, Mexico, 45 fath- oms, 4 specimens ( Turritella-stage) ; La Libertad, El Sal- vador, 18 fathoms, 1 specimen ( Turritella-stage) ; Gulf of Fonseca, El Salvador, 38-60 fathoms, 1 specimen (1 free whorl) ; El Salvador, exact locality unknown, 1 spe- cimen (3 free whorls, described above). Specimens of the adult stage were examined after the plate had been pre- pared, too late for illustration in this paper. Discussion: Vermicularia frisbeyae has a wide distribu- tion in the Panamic province. It has escaped detection until now evidently because it lives at depths less frequent- ly collected by dredging. The only eastern Pacific or western Atlantic species of Vermicularia having the large Turritella-stage is V. fargoi Ousson, 1951, from the Gulf of Mexico, which occurs at low tide on mud-flats. Vermicularia fargoi is a variable species but generally has 3 prominent spiral cords per whorl rather than 2 as in V. frisbeyae. Turritella willetti McLean, spec. nov. (Plate 46, Figures 7, 8) “Turritella sanguinea Reeve, 1849.” -—SwHasxy, 1961, p. 23; pit. 4, fig. 15. Description of Holotype: Shell moderately large, taper- ing, whorls 21, with thin periostracal remnants, nuclear whorls lost; earliest whorls highly convex with deep su- tures, under magnification the spiral sculpture on about the 6" whorl consisting of about 16 narrow, raised threads with slightly broader interspaces; at about the 9" whorl 5 of the threads become more prominent and the area below the 3"¢ thread from the base bevels in toward the suture, the cording above tending to become flat sided, rather than convex as in the early whorls. On the pen- ultimate whorl 5 strong cords remain, the general effect is of flat sided whorls, beveling in above and below the suture. The base is rounded and there are faintly indicated spiral cords. Aperture nearly circular, lip thin; growth-line trace slanting backwards, forming a broad, shallow sinus close to the anterior suture. Color whitish with brown maculations, stronger cords with alternating light and dark markings. Height, 73.0 mm, diameter, 13.7 mm. Type Material: Holotype, LACM 1280; 2 paratypes, LA CM 1281; 1 paratype, AMNH 154686; 1 paratype, CAS 13274; 1 paratype, SDNHM 51303; 1 paratype, SU 9989, 1 paratype, USNM 679556. Additional paratypes are in the Shy collection. Type Locality: Santiago Bay, Manzanillo, Colima, Mexi- co, 19°06’ N, 104°23’ W, 7-12 fathoms. The type lot was dredged by Laura and Carl Shy of Westminster, Cali- fornia, November and December, 1968. Referred Material: AHF 1087-40, Ensenada de San Francisco, Sonora, 15-18 fathoms; AHF 947-39, Isabel Island, Mexico, 15-25 fathoms; LACM A.375, Chamela Bay, Jalisco, Mexico, 15-40 fathoms; LACM A.375, Tena- catita Bay, Jalisco, 20-40 fathoms; LACM A.375, Zihu- Explanation of Plate 46 Figures 1, 2: Arene guttata McLEan, spec. nov. Holotype, LACM 1275. Santa Cruz Island, Galapagos Islands. Height 4.5 mm, dia- meter 5.0mm x 6 Figures 3, 4: Arene echinata McLean, spec. nov. Holotype, AMNH 154626. Fernandina Island, Galapagos Islands. Height 8.5 mm, dia- meter 8.0mm x4 Figure 5: Vermicularia frisbeyae McLean, spec. nov. Holotype, LACM 1278. Manzanillo, Mexico. Height 26.8mm, diameter 10.8 mm X15 Figure 6: Vermiculania frisbeyae, holotype, detail of early whorls XK 3 Figure 7: Turritella willetti McLEan, spec. nov. Holotype, LACM 1280. Manzanillo, Mexico. Height 73 mm, diameter 13.7mm XX 1 Figure 8: Turritella willetti, holotype, detail of early whorls X 3 Figure 9: Natica brunneolinea McLean, spec. nov. Holotype. LA CM 1282. Santa Cruz Island, Galapagos Islands. Height 10.8 mm, diameter 10.5 mm xX 3 Figure 10: Natica brunneolinea. Paratype, LACM 1283. Height 45.8mm, diameter 42.3 mm XI Figure 11: Natica sigillata McLeEan, spec. nov. Holotype. LACM 1284. Isabella Island, Galapagos Islands. Height 10.0mm, dia- meter 10.5 mm X3 Figure 12: Natica sigillata. SU 49428. Carmen Island, Mexico. Height 19.5 mm, diameter 19.2 mm X 2 Figure 13: Cantharus (Gemophos) berryi McLEAN, spec. nov. Holotype, LACM1286. Banderas Bay, Mexico. Height 21.1 mm, diameter 11.7 mm XK 1.5 Figure 14: Cantharus (Gemophos) berryi. Paratype, LACM 1286. Showing egg capsules attached to the shell. Height 20.8 mm, dia- meter 12.7 mm X 1.5 Figure 15: Fusinus allyni McLean, spec. nov. Holotype, LACM- AHF 1290. Daphne Minor Island, Galapagos Islands. Height 88.4 mm, diameter 34.2 mm XI Figure 16: Fusinus allyni. Paratype, LACM-AHF 1291. Height 70.6 mm, diameter 34.6 mm XI Figure 17: Fusinus allyni. Paratype, LACM-AHF 1291. Height 40.0 mm, diameter 14.3 mm X15 Tue VELIcER, Vol. 12, No. 3 Figure 12 Figure 13 Figure 14 Figure 15 [McLean] Plate 46 Vol. 12; No. 3 atanejo, Guerrero, Mexico, 20-40 fathoms. The last 3 lots were dredged by the late George Willett in 1938. Discussion: Turritella willetti is a species familiar to collectors having dredged along the Mexican coast. SHAS- Ky (1961) attempted to equate the species with REEVE’s Turritella sanguinea (REEveE, 1849, p. 6, fig. 27), which was said to be from “California.” In REEve’s illustration the final whorls are also convex and other details of sculpture and color pattern do not correspond. REEVE’s taxon is most likely not West American. Turritella willetti, with its strongly convex early whorls, cannot be confused with other eastern Pacific species, all of which have fewer spiral cords on the early whorls. The cording of the mature whorls is variable and is similar to the pattern observed in T: mariana Dati, 1908. The largest specimen observed measures 81 mm in length. Turritella willetti is named for the late George Willett of the Los Angeles County Museum of Natural History, first person to collect specimens of the material at hand. Willett’s collecting in Mexico in 1938 greatly enriched the Museum’s collections. Natica brunneolinea McLEan, spec. nov. (Plate 46, Figures 9, 10) Description of Holotype: Shell thin, umbilicate, spire low, whorls rounded, surface of final whorl with thin yellowish periostracum. Nuclear whorls 3, glossy, first nuclear whorl dark brown; postnuclear whorls 24, sculp- tured with fine retractive axial grooves strongest just be- low the suture and extending only halfway to the peri- phery. Outer lip thin, umbilicus narrow, partially ob- structed within by thick spiral ridge terminating on the inner lip; parietal callus extending slightly forward near the umbilicus. Color yellowish on upper portion of whorl, base below the periphery whitish, marked with irregular brown pencilled lines on the peripheral area only. Operc- ulum calcareous, white, with 2 deep grooves at the outer edge. Height, 10.8 mm, diameter, 10.5 mm. The largest paratype (LACM), which lacks the operc- ulum, has 4 postnuclear whorls and measures: height, 45.8mm, diameter, 42.3 mm. Type Material: Holotype, LACM 1282; 1 paratype, LA CM 1283; 1 paratype, SDNHM 51304; 1 paratype, US NM 679557; 1 paratype, AMNH 154687. Type Locality: Academy Bay, Santa Cruz Island, Gala- pagos Islands, Ecuador, 0°45’ S, 90°20’ W, 50-100 fath- oms, dredged by André and Jacqueline DeRoy, 26 April 1967 (3 specimens), 27 May 1968 (1 specimen), 9 December 1968 (1 specimen). THE VELIGER Page 313 Referred Material: Galapagos Islands, Ecuador: AHF 190-34, S end Albemarle Island, 58-60 fathoms, 3 speci- mens; AHF 810-38, Barrington Island, 48-73 fathoms, 2 specimens; AHF 814-38, N of Hood Island, 20-40 fath- oms, 3 specimens; AHF 816-38, N of Hood Island, 50-100 fathoms, 1 specimen with operculum; AHF 817-38, N of Hood Island, 140-160 fathoms, 1 specimen. Discussion: Natica brunneolinea reaches a large size; the paratype measuring 45.8 mm in height is larger than spe- cimens of other Panamic species examined. It is the only eastern Pacific species having the color pattern of vertical brown lines on the upper part of the whorl, hence the name. The doubly grooved operculum is known in Natica grayt Puiwippi, 1852, and N. scethra Datu, 1908, but these species are smaller and have spiral rather than axial color patterns. Natica sigillata McLzaun, spec. nov. (Plate 46, Figures 11, 12) Description of Holotype: Shell globose, narrowly umbili- cate, spire low, whorls rounded, surface of final whorl with thin yellowish periostracum. Nuclear whorls 14, glossy, yellow brown; postnuclear whorls 34, smooth ex- cept for fine lines of growth. Outer lip thin, umbilicus narrow, columellar wall not greatly thickened, spiral um- bilical cord lacking, a short tongue of white callus extends slightly across the whorl, but not obstructing the umbili- cus; parietal callus between this tongue and the upper edge of the lip not developed, resulting in an uncalloused band on the parietal wall extending within the aperture. Color chestnut brown with tent shaped markings of white, area immediately adjacent to umbilicus white. Operculum calcareous, white, with 4 raised ridges at the outer edge, the 2 inner ridges broader than the outer 2. Height, 10.0 mm, diameter, 10.5 mm. The largest paratype (LACM 1285), which lacks the operculum, measures: height, 14.9mm, diameter, 13.3 mm. Type Material: Holotype, LACM 1284; 1 paratype, LA CM 1285; 1 paratype, SDNHM 51305; 1 paratype, US NM 679558; 1 paratype, AMNH 154688. Type Locality: Tagus Cove, Isabella Island, Galapagos Islands, Ecuador, 0°16’ S, 91°22’ W, 50 fathoms, 4 spe- cimens, dredged by André and Jacqueline DeRoy, 25 and 29 January 1968. The LACM paratype was dredged at South Academy Bay, Santa Cruz Island, by the DeRoys, 11 June 1968. Referred Material: SU 49428, between Carmen Island and Loreto, Baja California, 20-45 fathoms, Ariel Expedi- Page 314 tion, 1960, 1 specimen lacking the operculum (Plate 46, Figure 12), height, 19.5 mm, diameter, 19.2 mm. Discussion: Natica sigillata is the only eastern Pacific species having a pattern of tent shaped markings. It differs from most eastern Pacific species in lacking the axial grooves below the suture and in lacking a thickened umbilical ridge. This species must evidently have a wide distribution although it is presently known only from the Galapagos Islands and from one specimen from the Gulf of Califor- nia. The latter specimen shows the large tent markings only near the suture and on the base, and the general coloration is yellowish brown rather than dark brown, but the color may have faded. The name is a Latin adjective meaning adorned with little figures or marks, with reference to the color pattern. Cantharus (Gemophos) berryi McLean, spec. nov. (Plate 46, Figures 13, 14) Description of Holotype: Shell of rather small size, sturdy, spire elevated, whorls rounded, subangulate at the - periphery. Nucleus of 14 whorls, rounded, brown. Post- nuclear whorls 6, axial sculpture of approximately 10 low costae per whorl, weakly developed below the suture and along the canal; spiral sculpture over-riding the axial sculpture, consisting on the penultimate whorl of 5 nar- row cords at the crests of broader spiral ridges, with about 5 thin raised spiral lirae between each crest of the spiral cords. On the final whorl there are approximately 14 cords below the suture, with 6-8 spiral lirae between each 2 cords. Aperture ovate, canal oblique and broadly open, aperture and canal extending more than 4 the length of the shell, outer lip thick, 14 white spiral lirae within, edge of lip finely crenulate; inner lip well defined with callus; anal notch slightly constricted, bordered on parietal wall with a low ridge of callus; siphonal fasciole ridged around a slight umbilical chink. Periostracum thin, yellowish, closely adherent. Color yellowish white, axial ribs dark brown near the crests of the spiral ribs, axial color missing on the shoulder. Operculum with api- cal nucleus, dark brown, outer margin yellowish. Height, 21.1 mm, diameter, 11.7 mm. Type Material: Holotype, LACM 1286; 50 paratypes, LACM 1287; 25 paratypes, SU 9990; 3 paratypes, AM NH 154689; 3 paratypes, CAS 13275; 3 paratypes, SD NHM 51306; 3 paratypes, USNM. Additional paratypes are available for distribution to other institutions. THE VELIGER Vol. 12; No. 3 Type Locality: Off La Cruz, Banderas Bay, Jalisco, Mexico, 20°45’ N, 105°30’ W, 10-15 fathoms. The type lot, consisting of approximately 135 specimens, was dredged by James H. McLean and Myra Keen aboard the Sea Quest, 20 to 24 March 1965, guests of Mr. and Mrs. Richard FE Dwyer, of Corona del Mar, California. Referred Material: LACM, Banderas Bay, 45 speci- mens, dredged April 1963, by Cornelius Willis; LACM 65-17, La Cruz, Banderas Bay, 20 specimens collected by diving on sand bottom, 12 feet depth, James H. McLean, 25 March 1965; LACM A.5498, Chamela Bay, Jalisco, Capt. Fred E. Lewis, 8 specimens; LACM A.375, Tena- catita Bay, Jalisco, Mexico, 20-40 fathoms, George apes lett, 18 February 1938, 9 specimens. Cantharus berryi is known from a rather restricted area in the state of Jalisco, Mexico. In recent years it has been found only along the north side of Banderas Bay, where it is evidently fairly common on sand and mud bottoms offshore. I have a specimen on hand reputed to have been taken by shrimp fishery operations between La Paz and Mulege on the southeastern side of Baja California, but the record needs further verification in view of the limited distribution along the Mexican mainland. Discussion: Cantharus berryi is the smallest of the east- ern Pacific species of Cantharus. It is related to C. lautus (Reeve, 1846) and C. vibex (Broperip, 1833), two other species having yellowish or whitish shells with darker coloration along the axial ribs. The egg capsules of this species are evidently attached directly to the shell (Plate 46, Figure 14). Egg capsules were found on two of the approximately 200 specimens on hand. ‘To my knowledge, this has not been observed in other species of Cantharus (Gemophos). It is characteristic of most if not all species of Solenosteira Dati, 1890. The eastern Pacific Soleno- steiras differ in having larger, whitish shells having a coarse periostracum. The species is named for Dr. S. Stillman Berry, of Redlands, California, who has described a number of species of Solenosteira, among his numerous contributions to our knowledge of eastern Pacific mollusks. Fusinus allyni McLean, spec. nov. (Plate 46, Figures 15 to 17) Description of Holotype: Shell large, thin, light in weight, covered with a fine, yellowish periostracum; whorls in- flated, rounded, except for a sharply projecting periphery, suture deeply impressed. Apex missing, 9 whorls remain. Axial sculpture on the 4" whorl of 9, on the final whorl Vol. 12; No. 3 of 10 low ribs with broader interspaces, crossed on the 4 whorl by 4 and on the penultimate whorl by 6 major spiral ribs and numerous spiral threads of varying size, the peripheral spiral cord the most prominent, forming a keel with rounded projections on the last 3 whorls. Aper- ture ovate, outer lip thin, simple, but reflecting the spiral sculpture; columella with a thin white callus. Canal long, straight, siphonal fasciole lacking, length of aperture and canal greater than length of the shell. Color whitish, with reddish brown on the axial ribs between the major spiral cords. Operculum of holotype withdrawn. Height, 88.4 mm, diameter, 34.2 mm. A paratype specimen (Plate 46, Figure 16), with broken apex and canal, but with body whorls of similar proportions, has a projecting inner lip and a slightly in- flated outer lip, suggesting that 90 mm is about the maxi- mum size expected in this species. A paratype specimen (Plate 46, Figure 17), 40 mm in length, has an intact apex with 3 smooth nuclear whorls. Type Material: Holotype, LACM-AHF 1290; 3 para- types, LACM-AHF 1291; 1 paratype, CAS 13277; 1 paratype, USNM 679560. Type Locality: Off Daphne Minor Island, Galapagos Islands, Ecuador, 0°24’30” S, 90°22’40” W, 70-80 fath- oms, on mud, Velero III station 792 38, 20 January 1938, 6 specimens. Four of the 6 specimens were live-collected, inci tanty ° all va wy) THE VELIGER Page 315 2 are subadult and 2 are immature; the smallest of these is illustrated. Referred Material: Galapagos Islands: AHF 788-34, SE of Daphne Major Island, 55 fathoms, 1 broken juvenile; AHF 201-34, Gardner Bay, Hood Island, 25-35 fathoms, 1 immature specimen 56 mm in length. Discussion: As far as is known, Fusinus allyni is endemic to the Galapagos Islands. It differs from all other large offshore species in the Eastern Pacific in having a more inflated body whorl but thinner shell and thinner peri- ostracum. Fusinus allyni is named for Mr. Allyn G. Smith of the California Academy of Sciences, in recognition of his continuing work with the eastern Pacific species of Fusinus. LITERATURE CITED Keen, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford, Calif. (Stanford Univ. Press) Reeve, Lovett Aucustus 1849. | Monograph of the genus Turritella. 5: 11 pits. Suasxy, Donatp R. 1961. Notes on rare and little known Panamic mollusks. The Veliger 4 (1): 22-24; plt. 4, figs. 11- 16 (1 July 1961) Conch. Icon. (May-June 1849) Page 316 THE VELIGER Vol. 12; No. 3 Correlation of Radula Tooth Structure and Food Habits of Three Vermivorous Species of Conus BY JAMES NYBAKKEN ' Moss Landing Laboratories, Box 223, Moss Landing, California 95039 and Department of Zoology, University of Washington, Seattle, Washington 98105 (Plate 47) MEMBERS OF THE GENUS Conus have the most complex individual radula teeth of any mollusk. Each tooth is formed of a single sheet of chitin which is rolled as a sheet of paper is rolled, and is variously ornamented ex- ternally. The teeth are asymmetrical and difficult to rep- resent completely in line drawings (Plate 47, Figures 1, 2, 3). For more detailed descriptions of these teeth and for figures of the variations the papers of Corton (1945), Prete (1939), WarMKE (1960), and CLENcH & Konpo (1946) should be consulted. Apparently the rolled chitin sheet has a considerable amount of plasticity for the individual teeth of the various Conus species vary greatly in shape and in type of and arrangement of ornamentation such that individual species may, in some cases, be dis- tinguished from congeners on the basis of tooth structure alone. PIELE (op. cit.) gives an appreciation of the range of variation found in the genus in his illustrations. This variation in shape and structure among species was noted by several workers, but it was not until 1939 that PreLe arranged the teeth into groups of species with similar structure. Since then many workers have figured Conus teeth including, in addition to those mentioned above, BarNnarp (1958), Hanna (1963), ENDEAN & Rup- KIN (1965), and Von Mot, TurscH & Kempr (1967), but only ENpEAN & RupkKIN have attempted to relate a type of tooth structure to a specific prey utilized by the species. They describe the general shape of the teeth of fish-eating, mollusk-eating and worm-eating species, using PIELE’s categories. While they describe in some detail the structural features common to the teeth of the first two groups, by far the greatest number of Conus species feed on polychaetes and other worm-like invertebrates such * T should like to acknowledge support from NSF grant GB5942X as enteropneusts (KoHN, 1959; 1968). ENDEAN & Rup- KIN do not attempt to relate the features of radula structure of the few vermivorous species they studied to particular types of prey. They merely note that all vermi- vorous species seem to have a spur or cone on the base of the tooth, and that the teeth are rather short and squat in appearance. Since the great majority of Conus species are vermi- vorous and since the teeth of these species have a con- siderably wider range of interspecific variation in structure than those in either the known fish-eaters or mollusk- eaters, it is of interest to ask if in fact it is possible to correlate certain structural features of teeth or entire tooth structure with particular types of prey organisms. During the course of an investigation of the food habits of Conus species from Indonesian waters and from West American waters, I dissected 6 specimens of Conus zonatus Hwass, 1792, 2 C. imperialis LinNAgEus, 1758, and 3 C’. brunneus Woop, 1828 (Plate 47, Figures 4, 5, 6). The only remains found in the digestive tracts of C. zon- atus and C. brunneus were the setae of members of the polychate family Amphinomidae, a rather unusual family for Conus to prey upon (Koun, 1959). I found nothing in the 2 C. imperialis, but KoHN (of. cit.) has shown them to feed primarily upon amphinomids. Since the radula teeth of C’. brunneus were known to me to be quite distinctive, I was stimulated to ask if the radula teeth of C. zonatus and C. imperialis were also similar. I subsequently checked the radula teeth of Conus zona- tus and C. imperialis, and they also proved to be highly distinctive and very similar to those of C’. brunneus (Plate 47, Figures 1, 2, 3). It thus seems reasonable to assume that this particular type of tooth structure is somehow useful in predation on amphinomids. Since this Vol. 12; No. 3 THE VELIGER Page 317 tooth structure is unique among the various Conus tooth types, I would suggest that other Conus species showing a similar type of tooth can also be expected to feed on amphinomids. For example, Von Mot, TurscH & KEMPF (1967) figure the radula tooth of C. regius GMELIN, 1791 which has a structure similar to those of the 3 species discussed here, and thus I would expect it to be a predator on amphinomids. The fact that Conus species prey on amphinomids at all is quite remarkable. The family Amphinomidae is a relatively small one distributed primarily circumtropically. The species are commonly known as “fire worms” (Day, 1967). This name derives from the fact that they have large, long, hollow setae which break easily upon touch and release contained poison into the lesions. This causes severe itching-burning sensations in man (CLELAND & SoutHcott, 1965). Day (1967) gives a concise discussion of the family and good illustrations of setae and worms. Why these few Conus species should choose to specialize in eating such formidable prey remains unknown as do the mechanisms which allow the Conus to consume the amphinomid without damage to itself. Amphinomids usually live under coral rock or other rock or in crevices in rocks in shallow water. They are usually fairly large worms which feed on sponges, ascidi- ans and hydroids (Day, op. cit.). Amphinomids are rarely, if ever, taken by other Conus species. KoHn (1959, 1968) does not report amphinomid remains from any other Conus species and dissection of 1300 Conus of 39 vermivorous species from Indonesia turned up only a single instance of amphinomid remains in a Conus outside of the described amphinomid eaters. This was in a specimen of Conus eburneus Hwass, 1792. However, the amphinomid eaters occasionally take other polychaetes. In a sample of 13 C. imperialis from the Seychelle Islands, one specimen was found to have eaten an unidentified species of the polychaete family Eunicidae. Thus far, the few specimens of C. zonatus and C. brun- neus which have had food in them had only setae of amphinomids, but the number of specimens examined re- mains too small to make meaningful statements about the amount of the diet composed of amphinomids. Figures 1 to 3 of Plate 47 show that in all 3 amphinomid predators each tooth has a small barb just back from the tip, followed by a very distinctive series of two large barbs about a third of the distance down the tooth shaft. Conus brunneus has 3 such barbs, C. imperialis and C. zonatus have but 2. The third barb of C. brunneus appears to be an accessory barb of one of the 2 large barbs. One of the latter protrudes at a slight angle from the long axis of the tooth and bears a set of denticles on its upper surface (Plate 47, Figures 1, 2, 3). The presence of these 2 barbs and of the denticles on the ridge of one of the barbs distinguishes the teeth of these amphinomid pred- ators. The remainder of the tooth is unornamented, but the base of the tooth is large with 1 (Conus brunneus) or 2 (C. imperialis, C. zonatus) protruding prominent bumps which can be termed spurs. The teeth of these 3 species are also very thick and massive when contrasted to most other species of Conus, and the radula sheaths each contain fewer teeth than are normally found in other vermivorous Conus species (usu- ally 4 to 6 immediately usable teeth in that part of the radula sheath adjacent to the esophagus as opposed to 8 to 15 in other vermivorous species that I have investi- gated). The teeth are large as indicated by a low shell length to tooth length ratio. This ratio averaged 25.1 for 13 teeth from 3 specimens of C. brunneus, 20.3 for 10 teeth from 2 C. imperialis, and 30.4 for 10 teeth from C. zonatus. Most vermivorous Conus species have shell/ tooth ratios of from 30 to 70 indicating small teeth (Koun, 1963). It is worth noting that the similarity in radula struc- ture and food habits is not reflected in shell morphology (Plate 47, Figures 4, 5, 6). Whereas Conus imperialis and C. zonatus have similar tapering shells with straight sides, C. brunneus has a convex outline to the body whorl and is a shorter and more obese shell. It also lacks the striking color patterns seen in C’. imperialis and C. zonatus. The aperture is wide in C. brunneus as contrasted with the other 2 species, and the interior is not partially obstructed by an internal ridge as is the case in C. zonatus. These differences in shell morphology would seem to disallow the use of any shell characters in predicting food in this group whereas this does not seem to be the case in the fish eating Conus species, all of which seem to be charac- terized by a wide aperture. It should be noted that C. imperialis and C.. zonatus are considered to be closely re- lated, and the color patterns are often more similar than the present figures suggest. This paper is but the first attempt to correlate specific types of radula teeth with particular prey organisms among the vermivorous Conus species. The teeth of the species described here are very distinctive and have been shown to correlate with a distinctive prey type. However, the great majority of radula tooth types found in the vermivorous Conus species have not as yet been related to specific prey types and other such correlations should be looked for among these types. It is hoped that this paper will stimulate this work. Page 318 LITERATURE CITED BaRNaRD, KEPPEL Harcourt 1958. Contributions to the knowledge of South African marine Mollusca. Part I. Gastropoda : Prosobranchia : Toxoglossa. Ann. So. African Mus. 44 (4): 73 - 163 CLELAND, JoHN B. & R. V. SoutrHcott 1965. Injuries to man from marine invertebrates in the Aus- tralian region. Canberra: Nat. Health & Med. Res. Coun- cil Rept. no. 12: 282 pp. CLENCH, WILLIAM JAMES & YOSHIO Konpo 1946. The poison cone shell. Occ. papers Moll. 1 (7): 52 - 80 Corton, BERNARD CHARLES 1945. A catalogue of the cone shells (Conidae) in the South Australian Museum. Rec. South Austral. Mus. 8 (2): 229 to 280; 5 plts.; 1 text fig. Day, J. H. 1967. A monograph on the Polychaeta of Southern Africa. Brit. Mus. (Nat. Hist.) Publ. no. 656; 878 pp. London ENDEAN, RoBERT & CLARE RUDKIN 1965. Further studies of the venom of Conidae. Toxicon 2: 225 - 249 THE VELIGER Vol. 12; No. 3 Hanna, G Datias 1963. | West American mollusks of the genus Conus; II. Calif. Acad. Sci. Occ. Papers 35:1- 103; plts 1-11 (28 Jan. 1963) Kon, ALAN Jacogs 1959. The ecology of Conus in Hawaii. Ecol. Monogr. 29: 47 - 90. 1963. | Venomous marine snails of the genus Conus; in: Ven- omous and poisonous animals and noxious plants of the Pa- cific area. Pergamon Press, New York; 456 pp. 1968. Microhabitats, abundance and food of Conus on atoll reefs in the Maldive and Chagos Islands. Ecology 49 (6) : 1046 - 1062 PIELE, A. J. 1939. Radula notes, VIII. Conus. London 23 (6): 348 - 355 Von Mot, JEAN-JAcQUES, BERNARD TurRScH & M. KEMPF 1967. | Campagne de la Calypso au large des cétes atlantiques de l’Amerique du Sud (1961-1962) 16. Mollusques proso- branches: Les Conidae du Bresil. Res. Scient. Camp. Ca- Proc. Malacol. Soc. lypso 8. Ann. Inst. Oceanogr. 45 (2): 233 - 254 WarMKE, GERMAINE L. 1960. Seven Puerto Rico cones: notes and radulae. The Nautilus 73 (4): 119-124 Explanation of Plate 47 Figure 1: Radula tooth of Conus zonatus Figure 2: Radula tooth of Conus imperialis Figure 3: Radula tooth of Conus brunneus (scale = 0.5mm) Figure 4: Conus zonatus; length 58.3 mm, A. J. Kohn coll. no. 4384 Figure 5: Conus imperialis; length 72.2 mm, A.J.Kohn coll. no. 1728 Figure 6: Conus brunneus; length 46.1 mm, J. Nybakken collection THE VELIGER, Vol. 12, No. 3 [NyBAKKEN] Plate 47 Vol. 12; No. 3 THE VELIGER Page 319 Observations on the Reproductive Biology of the Kellet’s Whelk, Kelletia kelletiu (Gastropoda : Neptuneidae) RICHARD J. ROSENTHAL Westinghouse Ocean Research Laboratory, San Diego, California 92121 (Plates 48 and 49; 4 Text figures) INTRODUCTION THe KeELiet’s WHELK, Kelletia kelletu (Forses, 1850) (Plate 48) has been reported along the eastern Pacific Ocean from Santa Barbara, California, to San Quentin Bay, Baja California (Appott, 1954, p. 231). Kelletia kelletu is commonly found off southern California in kelp beds and on nearshore reefs. Its vertical distribution is typically subtidal, extending from 2 to about 70m in depth. Kelletia kelletu has a relatively large spindle-shaped dextrally spiralled shell. It is one of the larger gastropods found in southern California waters. During this study the largest individual had a shell length of 148 mm. Although K. kelleti is one of the more abundant species of the Neptuneidae found in southern California, it has not been studied extensively and the literature contains only brief discussions on the biology of this gastropod (Mac- Ginitie, 1949; LimpaucH, 1955). This paper is concerned with the reproductive biology of Kelletia kelletu. Observations were made during 1968 and 1969 both in the experimental tanks of the U.S. Bu- reau of Commercial Fisheries at La Jolla, California and while diving on nearshore reefs off San Diego County. MATING BEHAVIOR The sexes are separate in Kelletia kelletu, and mature males can be identified by the presence of a penis located in the head region back of the right tentacle within the mantle cavity. During the reproductive season the mature testis is usually reddish-brown, and the mature ovary is yellow-orange. Paired individuals have been sighted as early as January during 1968 and 1969. Fertilization is internal and the copulatory act was observed frequently during March, April and May of both years. During copu- lation, the male grasps the female’s shell with his foot and the outer lips of both shells are usually brought close together. The male then extends his penis over the outer lip of the female’s shell between the foot and the mantle cavity (Plate 49). Mating appears to be somewhat size-selective, since the female was generally the larger member of the copulating pair (Text figure 1). The female had a mean shell length 13 mm larger than the male partner in the 124 copulating pairs observed. The shell lengths in these mating pairs ranged between 62 - 120 mm for the males and between 71 - 121 mm for the females. Sexually active males greater than 80 mm in shell length were available to the spawning population; yet in only 11 out of the 124 copulating pairs was the male larger than the female. The shell length (siphonal canal to the apex) was determined by measuring each individual to the nearest mm with plastic calipers either underwater or in the laboratory. Males seem to attain sexual maturity at a smaller size (earlier age) than do the females. Whether this is the result of sexual differences in growth rate or due to a delay in spawning by females until larger size is obtained has not yet been determined. PEarcE & THORSON (1967) believe that female Neptunea antigua (LINNAEUS, 1758) postpone spawning until they have attained full size, and that males become sexually active at a smaller shell size than females. Sexual dimorphism in prosobranch mol- lusks has been observed in various species with the female generally larger than the male (Hyman, 1967). E>warps (1968) observed, however, that male Olivella biplicata (Sowersy, 1825) were significantly larger and grow more rapidly than the females. Page 320 120 100 ie}e) Length of female (mm) 80 70 60 70 80 THE VELIGER Vol. 12; No. 3 go 100 110 120 Length of male (mm) Figure 1 A comparison between the lengths of females and males in 124 copulating pairs. These pairs were measured underwater (in depths of from 18m to 25m) between 11 April and 16 May, 1969. - = I pair The size differential in a mating pair may be of benefit to the female Kelletia kelleti, since she has the ability to move around more easily with a smaller size male at- tached to her shell during mating or egg deposition or both. Distinguishing sexes in the field is usually relatively easy since the anterior ends of both members are generally Four locations off San Diego county were investigated: Point Loma (32°43’N Lat.); Bird Rock (32°49’N Lat.); Point La Jolla (32°51’30” N Lat.) ; and Del Mar (32°57’ N Lat.). + = 2 pairs pointed in the same direction, with the male on the right side or on top of the larger female. Copulation has been observed prior to and during ovi- position. One female (102 mm) was observed in the labo- ratory to copulate 6 times with 5 different male partners over a 30-day period. In each instance, egg laying either followed or took place simultaneously during copulation. [RosENTHAL] Plate 48 THE VELIGER, Vol. 12, No. 3 JoyeMiopun UL OG 2179]]94 D1J2]]9 SJ g[euof surumeds V Te é oe . se! = a, F « -—* Vol. 12; No. 3 THE VELIGER Page 321 SPAWNING BEHAVIOR Spawning commenced during April both in the labora- tory and in the subtidal areas examined during 1968 and 1969. The water temperatures at 20 - 25 m for April 1969 in the vicinity of La Jolla, California ranged from approximately 10.5° C to 13.8° C, compared to 14.5° C to 16.9° C in the experimental tanks at the U.S. Bureau of Commercial Fisheries Laboratory. Orton (1920) pointed out that the temperature gen- erally controls the process of gonadal ripening in marine invertebrates, and that to spawn most invertebrates seem to require much higher temperatures than are necessary at other periods. The data collected on Kelletia kelletu suggest that factors other than just temperature are in- volved in the inducement of spawning. Oviposition in the laboratory has coincided with spawning in subtidal regions even though it occurred on the same day at sig- nificantly different water temperatures — such as 10.5° C at a depth of 20 m off Point Loma, California, compared to 16.5° C in the laboratory water table. Five spawning females which were tagged underwater (RosENTHAL, 1969) in April 1968 were located in April or May. of the following year and found to be either copulating or depositing egg capsules for the second year in a row. It is believed that spawning takes place annu- ally in mature females (> 70 mm), and that the greatest reproductive success is reached when the female is be- tween 80 - 90 mm in shell length (Text figure 2). The females deposit their egg capsules on almost any available hard substrate such as rocks, discarded mollusk 50 eo o -» a oa [e} Number of females go 100 110 ‘120 Shell length (mm) Figure 2 The shell lengths of egg laying females. A total of 170 ovipositing individuals were measured between 11 April and 16 May, 1969 shells, or even on the shells of living Kelletia kelletit. Oviposition in the aquaria generally was confined to the vertical sides of the tanks. In subtidal regions the animals usually favor low relief rocky substrates which are rela- tively free of sessile macro-organisms. Egg-laying females have not been observed depositing capsules on substrates occupied by large numbers of sea urchins. During the height of the egg-laying period (April to May) extensive aggregations oi both male and female Kelletia kelletu have been seen repeatedly in a kelp bed off Del Mar, California. On 30 April 1968, between 200 and 300 individuals were observed in a spawning aggre- gation contained within a 20 m? area at a depth of 19 m. Aggregations of 15 to 20 individuals are quite common within this kelp bed during the spawning season. Aggregations of spawning gastropods have been ob- served in Strombus gigas LinnaEus, 1758 by D’Asaro (1965), and in Urosalpinx cinerea (Say, 1822) by Car- RIKER (1955). It has been indicated by Pearce & THor- son (1967) that adult Neptunea antigua aggregate during the spawning season. Kelletia helletw is generally found in an aggregated distribution pattern throughout the year, but large numbered groups have been observed only dur- ing communal feeding and spawning activities. It is felt that mass aggregations of K. kelleti during the spawning season may be the result of chemoreceptive detection of the egg capsules or mucous trails of sexually active snails. Spawned egg capsules may act as additional stimuli to other mature females which encounter these capsules. Spawning females seem to favor ovipositing on substrates which already contain K. kelleti: egg capsules. Spawning inducement of this sort was observed by D’Asaro (1966) in the gastropod Thais haemastoma floridana Conrab, 1837. Aside from chemoreception, the egg depositing stimulus may be influenced by tactile responses in the foot and head region of mature females encountering egg cap- sules on the substrate. It seems likely that a series of factors, such as gonadal ripeness, fluctuating temperatures, proper substrate, and the presence of other spawning females may trigger egg deposition in K. kelletit. In the laboratory a female Kelletia kelletu (104 mm) was known to spawn on 4 different occasions over a period of 30 days, depositing a total of 85 egg capsules during this period. Another spawning female (78 mm) laid 22 capsules over a 24-hour period for a mean per hour rate of 0.92 capsules. If the female was disturbed in the aquari- um while egg laying, the spawning act might halt and be resumed again at some later time. In subtidal areas tagged female K. kelletit have been observed depositing egg clusters one day, and on subsequent days these same individuals were found laying additional egg capsules in new locations. CARRIKER (1955) observed that spawning Urosalpinx cinerea females did not always deposit their Page 322 egg capsules at one time, but may lay a number of egg clutches throughout the spawning season. Following ovi- position, the K. kelletii move away from their egg capsules and there is no attempt to guard or brood these capsules. EGG CAPSULES, EGGS, anp DEVELOPMENT The egg capsule, or ootheca, is the protective enclosure housing the eggs during the developmental period up to the time of hatching. The ventral pedal gland in the middle of the foot manipulates and hardens the capsule into a definite shape, and secretions are added to cement each capsule firmly to the substrate by an adhesive gela- tinous base. Formation and secretion of the stenoglossan egg capsule has been extensively reviewed by FRETTER (1941). The egg capsules are ovoid and somewhat deflated in shape, one face of the capsule is slightly convex (Plates 48, 49), When first deposited they appear translucent THE VELIGER Vol. 12; No. 3 white but darken with the passage of time due to the development and pigmentation of the larvae within the egg capsules. The capsules are attached to the substrate by one end and are usually deposited in groups or clusters, seemingly without any definite pattern or order. The free end of the capsule is closed with a proteinaceous plug that weakens and dissolves as the embryos reach the hatching stage. The height of the egg capsule is dependent upon the size of the spawning female Kelletia kelleti. During labo- ratory observations a female 78 mm in shell length depos- ited egg capsules with a mean height of 7.5 mm compared to a 120mm female which laid capsules 12.3 mm in height. Individual egg capsules obtained from different females contained between 400 and 1022 eggs, although occasionally a few egg capsules in a cluster are empty. MacGiniTiz (1949) reported counting 2182 eggs in one K, kelletit capsule. The newly spawned eggs are yellow in color, each one between 200 and 300u in diameter. The egg undergoes a typical spiral determinate cleavage pattern with the Figure 3 Trochophore stage of Kelletia kelletii after 13 daysin the egg capsule THE VELIGER, Vol. 12, No. 3 [RosENTHAL] Plate 49 A copulating pair of Kelletia kelletu E = egg capsules F = female M = male P = penis 5 ih i i EY P { z = ! : / | 1 a Vol. 12; No. 3 THE VELIGER Page 323 Figure 4 Kelletia kelletti veliger larva, 1 day prior to hatching embryo passing into a trochophore (Text figure 3) and then a veliger stage (Text figure 4) prior to emergence from the capsule. The incubation time seems to be dependent on the water temperature, although the hatching rate can be highly variable in different egg capsules developing under similar water conditions. SCHELTEMA (1967) has demon- strated the relationship of temperature to the time re- quired between spawning and emergence of veligers from their egg capsules in the gastropod Nassarius obsoletus (Say, 1822). In the laboratory the hatching period for Kelletia kelletw was 30 to 34 days for capsules developing in water temperatures between 14.5°C and 17.5° C. The early embryonic stages are extremely sensitive to changes in the water temperature — early cleavage stages were killed when taken from water 16.8° C and placed into water temperatures between 22.5° C and 24.0° C. In comparison, egg capsules containing late stage veligers, when taken from these same water conditions, hatched after only one day in the elevated water temperatures. The newly hatched Kelletia kelletii larvae emerge as free swimming veligers from the opening created by the dissolving of the gelatinous plug in the free end of the capsule. From this point they are carried into the water column to begin a planktonic existence until settlement is achieved. ACKNOWLEDGMENTS I would like to thank the following individuals for assist- ance with this study: R.E. Bower, J. R. Chess, W.D. Clarke, R. Lasker, G. Mead and G. Theilacker. I am also grateful to the U.S. Bureau of Commercial Fisheries Laboratory, La Jolla, California, for providing laboratory facilities without which this study could not have been completed. LITERATURE CITED Assott, RoBERT TUCKER 1954. | American seashells. Princeton, New Jersey, D. van Nostrand Co., Inc.; xiv+541 pp.; 100 text figs.; 40 plts. CarrikER, MELBOURNE ROMAINE 1955. Critical review of biology and control of oyster drills Urosalpinx and Eupleura. Special Sci. Rep. U.S. Fish & Wildl. Serv.: Fisheries no. 148: 1 - 150 D’Asaro, CHartes N. 1965. | Organogenesis, development, and metamorphosis in the queen conch, Strombus gigas, with notes on the breeding habits. Bull. Mar. Sci. 15 (2): 359 - 416 1966. The egg capsules, embryogenesis, and early organogen- esis of a common oyster predator, Thais haemastoma floridana (Gastropoda: Prosobranchia). Bull. Mar. Sci. 16 (4): 884 - 914 Epwarps, DaLLas CRAIG 1968. Reproduction in Olivella biplicata. 10 (4) : 297 - 304; plt. 44; 3 text figs. FRETTER, VERA 1941. The genital ducts of some British stenoglossan proso- branchs. Journ. Mar. Biol. Assoc. U. K. 25: 173 - 211 Hyman, Lippy HENRIETTA 1967. The invertebrates: Mollusca I. New York; viit+792 pp.; 249 figs. Koun, ALAN JAcoBs 1961. | Chemoreception in gastropod molluscs. 1: 291 - 308. LimBAUGH, CONRAD 1955. Fish life in the kelp beds and the effects of kelp har- vesting. Univ. Calif. Inst. Mar. Res. ref. 55-9; 158 pp. MacGinirtieE, Georce Eser & Nettie MacGIniriz 1949. Natural history of marine animals. McGraw-Hill, New York. The Veliger (1 April 1968) McGraw Hill Book Co., Am. Zool. 473 pp.; illus. Page 324 THE VELIGER Macauass, Hutpa 1948. An ecological study of snails of the genus Busycon at Beaufort, North Carolina. Ecol. Monogr. 18: 378 - 409 Orton, Joun H. 1920. Sea temperature, breeding and distribution of marine animals. Journ. Marine Biol. Assoc. U.K. 12: 339 - 366 Pearce, Jack B. « GUNNAR THORSON 1967. The feeding and reproductive biology of the red whelk, Neptunea antigua (L.) (Gastropoda, Prosobranchia). Ophelia 4: 277 - 314 ROSENTHAL, RicHarp J. 1969. A method of tagging mollusks underwater. The Veliger 11 (3) : 288 - 289; 1 text fig. (1 January 1969) ScHELTEMA, Rupo-r S. 1967. The relationship of temperature to the larval develop- ment of Nassarius obsoletus (Gastropoda). Bio]. Bull. 132: 253 - 265 TuHorson, GUNNAR 1950. Reproductive and larval ecology of marine bottom in- vertebrates. Biol. Rev. 25 (1): 1-45. Vol. 12; No. 3 Vol. 12; No. 3 THE VELIGER Page 325 The West American Species of Murexiella, (Gastropoda : Muricidae) Including Two New Species EMILY H. VOKES Department of Geology, Tulane University, New Orleans, Louisiana 70118 (Plate 50) ON A RECENT COLLECTING TRIP to Panama I was delighted to be presented with what I thought must be a new species of Murexiella. To be certain, I checked with Dr. Myra Keen, Stanford University, the acknowledged expert on Panamic Muricidae and discovered that this was the spe- cies she had figured in her Sea Shells of Tropical West America as “Maxwellia (?) humilis (Broperip, 1833)” (1958, p. 354, fig. 342). As I had considered a somewhat different species to be “Murex” humilis Broperip, this led to further correspondence with Dr. Keen and the ultimate conclusion that her figured specimen was, in fact, not “Murex” humilis but the new species described below as Murexiella keenae. Although KEEN (op. cit,) referred this shell to the genus Maxwellia, subsequent work by EMERSON (in prep- aration) has shown that the type of this group should no longer be placed in the Muricinae. Both the new species and “Murex” humilis are more correctly referred to the genus Murexiella CLENCH & PEREZ FARFANTE, 1945 (type species: Murex hidalgot Crossr, 1869). This genus is characterized by having an almost circular aperture with no anal notch and from 4 to 10 foliaceous varices, which have the fronds connected by a complex laminated web- bing. Study of the new species of Murexiella led to an investi- gation of the entire West American group of species that belong to the genus. The group is separable into two divisions: the Murexiella humilis complex and the Mur- extella lappa (BropEriP) complex with 7 nominal species in the first’ and 6 in the second. The members of the “humilis” complex have a globose body whorl, sharply constricted into an elongate siphonal canal. The varices bear elaborate frondose spines. The members of the “lap- * Another new species described by Emerson « D?Artizio in the present number of The Veliger brings the total to 8. pa” group have a biconic outline, with almost no notice- able break between body whorl and canal. The spines are short, stubby, and only slightly fimbriated. The species included in this division are most like Murexiella glypta (M. SmirH) of the western Atlantic Pliocene to Recent and all are probably descended from an as-yet unknown common ancestor. In a recent paper describing a new species of Murexsul from the Galapagos Islands, EMEr- son & D’Attitio (1969, p. 325) placed the “lappa” spe- cies in the genus Murexsul (type species: “Murex” octogonus Quoy & GarmarD, 1833). Although I agree completely with these authors that their new species is a Murexsul, I cannot place the other species in that group. There is considerable similarity of morphology between the two, but the intervarical webbing, although greatly reduced, is still present in the species under discussion. Also, the coloration and the nature of the aperture with its small, circular opening and raised peristome indicate that the West American species are closer to Murexiella than to Murexsul. As I have said before, and will continue to say, we must never forget that all supraspecific groups are completely artificial and the boundaries between the ar- bitrarily separated “natural groups” must be gradational. For this reason there will always be those intermediate species that might be just as well placed in either of two adjacent groups. The species of the “lappa” complex are in that position. “Murex” humilis was originally described from Santa Elena, Ecuador (Broperip, 1833, p. 175), and was first figured by G. B. Sowersy, Jr. (1834, plt. 65, figs. 46, 47). These figures show a shell with a marked brown spiral band circling the body whorl at the shoulder. The tips of the spines and the siphonal canal are brown, with a white band at the base of the body whorl. The specimen figured here (Plate 50, Figures 1 - 3) is from off Guaymas, Mexi- co, and has slightly different coloration. In it the brown Page 326 shoulder band is confined to the area immediately adja- cent to the suture, not extending as far as the row of spines at the shoulder. A second narrow band encircles the body whorl just at the juncture with the siphonal canal. Thus what is white or brown in the Ecuadorian shell is reversed in the Mexican one. The tips of the spines are brown in some Mexican specimens, although not in the one figured. The possession of some sort of spiral brown stripes is almost characteristic of Murexiella. Most of the West American species have these stripes developed to a greater or lesser degree. Some specimens of a species may occur in an all brown variant, but other specimens of the same species will be banded. The nature of the coloration, while consistent in its general appearance, is variable in partic- ulars. Murexiella hidalgoi, the western Atlantic type of the genus, has only a faint brown stripe, if any, in the adult stage, but the juvenile specimens often have a strong brown marking. Murexiella macginty: (M. Smrru, 1938) the western Atlantic “analog” of M. humilis, also has these stripes, which are most clearly indicated on the shoulder of the shell, appearing as brown blotches between the varices. This tendency toward brown and white stripes is found in other muricine genera, including Hexaplex s. s. and Phyllonotus, and suggests an original common ances- tor for the three groups. “Murex” norrisii REEvE, 1845 (Conch. Icon.: Murex, pit. 28, fig. 129), described without locality data and not discovered since, is very much like Murexiella humilis. Murexiella norrisii is a more elongate shell than M. hu- milis, with 3 small spines in the area between the base of the body whorl and the first large spine on the siphonal canal. Some specimens of M. humilis show a trace of these 3 small spines so that M. norrisii may prove to be only an extreme variant of M. humilis. However, until a specimen is found that more nearly matches the original material figured by Reeve, M. norrisii will be retained as a valid species. There are two specimens of this form in the col- lections of the British Museum (Natural History), which may or may not be the types, but they are consistent in their appearance so that the type cannot be dismissed as just a pathologic specimen of M. humilis. Another species of Murexiella described from the Gulf of California, “Murex” taeniatus SowErsy, 1860 (Proc. Zool. Soc. London, prt. 27, p. 428; plt. 49, fig. 3), may well also be a synonym of M. humilis. Kren (1958, p. 361, fig. 362) figured a large specimen of what seems to be Murexiella vittata as this species, noting the similarity to M. vittata at the time. Sowersy’s illustration shows a much more inflated shell than M. vittata, with 3 broad, dark brown spiral bands. In his original description he described the species as “fusco bifasciata,” but changed THE VELIGER Vol. 12; No. 3 this to “castaneo trifasciata” in the Thesaurus Conchyli- orum (1879, p. 29). His illustration shows a shell more akin to M. humilis than to M. vittata, to my eye, but as the type was not to be located in the British Museum in 1964, this species must remain a question mark for now. In fact, SowersBy’s illustration looks so much like the Atlantic species Murexiella macgintyi, I suspect there may be an error in the locality. The fourth species of the Murexiella humilis complex is “Murex” santarosana Datt, 1905 (Nautilus, vol. 19, p. 14). This species has been placed in the genus Max- wellia, but “Murex” gemma Sowersy, the type of _ Maxwellia, seems more closely related to the genus Aspel- la. The recently described species Aspella angermeyerae Emerson & D’Artiuio, 1965, from the Galapagos Is- lands, clearly demonstrates the link between the 2 groups. However, “Murex” santarosana is more like the other West Coast species of Murexiella, as I. discussed in a previous paper (E. H. Voxes, 1964, p. 14) without ap- preciating the true implications of the resemblance. The radula of M. santarosana is identical, however, as well as several points of shell morphology, to that of Maxwellia gemma and so it would seem that Murexiella santarosana is another of those intermediate species. As KEEN (1958, p. 354) noted, Murex fimbriatus A. Apams, 1853, non Murex fimbriatus Broccut, 1814, is a synonym of Murexi- ella santarosana. The fifth species of the Murexiella humilis group is “Murex” diomedaeus Dat, 1908 (Bull. Harvard Mus. Comp. Zool., vol. 43, p. 313; plt. 12, figs. 4, 5), described from 85 fathoms in the Gulf of Panama. Murexiella diomedaea * is the West American “analog” of Murexiella hidalgoi. As a photograph of this specimen has never been published, it seems desirable to include an up-to-date il- lustration of this lovely species (Plate 50, Figures 6, 7). In the collections of the American Museum of Natural History there is a specimen (no. 92435) of M. diomedaea taken by shrimpers off Cedros Island, Mexico, extending the range considerably to the north. The sixth member of the group is the new species from Panama mentioned above. It is the largest and most 2 The spelling of this name is somewhat dubious. In, the original description Datu spelled it diomedaeus; however, on the plate ex- planation he spelled it diomedae and on the labels with the holo- type it is spelled the same. The name is derived from Diomedea, the generic name for the Albatross, after the U.S. Fish Commis- sion Steamer “Albatross.” According to the ICZN Code the origi- nal spelling is considered to be correct unless a typographical error or a lapsus calami is obvious. Incorrect latinization is not considered as an “inadvertent error’ and is not to be emended. Therefore, whatever DaLu’s intention may have been, it seems best to retain the name as originally published, changing to a feminine termination to agree with the generic name Murexiella. Vol. 12; No. 3 massive of the group. Both it and the seventh, which is another new species discovered while I was engaged in this study, have been confused with Murexiella humilis in collections, but both represent valid forms. They are de- scribed at the conclusion of this paper. The members of the Murexiella lappa complex are all very much alike and considering the inherent variability of the genus Murexiella it is probable that not all of the named species are valid. All originally described as Murex, in chronological order of description they are: 1. Murexiella exigua (Broperip, 1833) [Proc. Zool. Soc. London, prt. 2, p. 174, described from Salango, “Co- lombia” (i. e., Ecuador) ; Sowersy, 1834, Conch. IIl., plt. 60, fig. 17.] This tiny shell, measuring % inch in height, is undoubtedly the juvenile of one of the species of Murexiella found on the West Coast, probably M. lappa. In the original description it is stated to have 5 varices and be of a “dirty-white” color but nothing more is known of the form. 2. Murexiella vittata (BropErip, 1833) [Proc. Zool. Soc. London, prt. 2, p. 176, from Guayaquil, Ecuador; Sowersy, 1834, Conch. Ill., plt. 60, fig. 19.] This spe- cies, while morphologically similar to M. lappa, is con- stant in the development of an almost black spiral stripe around the middle of the body whorl, which is visible on the inside of the shell as well as the outside. There are also other additional stripes at the shoulder and the base of the body whorl but they are not seen on the inside of the shell. This stripe, which gives the species its name (vittata means striped), can be seen even in very small individuals. I have one specimen 8 mm in height that has this stripe well developed. 3. Murexiella lappa (Broperip, 1833) [Proc. Zool. Soc. London, prt. 2, p. 177, from Santa Elena Bay, Ecuador; Sowersy, 1834, Conch. IIl., plt. 60, fig. 15.] This species has a broad, diffuse light brown band circling the body whorl. As is typical of all species of Murexiella the num- ber of varices is variable, from 5 to 7 in this case, in general decreasing with larger size. 4. Murexiella dipsacus (BropErip, 1833) [Proc. Zool. Soc. London, prt. 2, p. 194, also from Santa Elena Bay; Sowersy, 1834, Conch. Ill., plt. 60, fig. 20. It is well to note that the word dipsacus, meaning a teasel or thistle, is a noun and does not become dipsaca to agree with Murexiella.] This species is very close to M. lappa, but is a somewhat more elongate shell and was de- scribed as having 8 varices. It may be that the apparent elongation is a result of the extra varix and not a valid distinction. The color is identical with that of M. lappa, as is the number and arrangement of varical spines. THE VELIGER Page 327 I have never seen a specimen of M. dipsacus, nor have I ever seen a specimen of M. lappa with 8 varices, and the two species may well be the same. 5. Murexiella radicata (Hinps, 1844) [Proc. Zool. Soc. London, prt. 11, p. 128, from San Blas, Mexico; REEvE, 1845, Conch. Icon.: Murex, plt. 30, fig. 148.] The type specimen of this species differs only in having somewhat shorter spines than is shown in the illustra- tion given by Sowersy for M. lappa (the type of M. lappa is no longer to be found), and is actually the normal condition for the species. It is unquestionably a synonym of M. lappa. 6. Murexiella minuscula (M. Soir, 1947) [Nautilus, vol. 61, p. 54; plt. 2, fig. 8, from the Pearl Islands, Panama.] Named as a subspecies of M. vittata, this form was stated by SmirH to differ from M. vittata s. s. by its “much smaller size,” the holotype measuring 18.5 mm in height. The usual size of M. vittata is about 23 to 25 mm. He did not note that the coloration is com- pletely different, the shell being dark brown over most of the body whorl, with a white stripe where M. vittata has a black stripe. He did not compare his species with M. lappa, but it may well be the same. There is one other species of Murexiella to be found in the eastern Pacific. This is Murexiella perita (Hinps, 1844) [Proc. Zool. Soc. London, prt. 11, p. 129; REEvE, 1845, Conch. Icon.: Murex, plt. 29, fig. 139], which is unlike either of the groups discussed above. It is most like Murexiella levicula (Dat, 1889), from the Gulf of Mexico, but lacks the marked median groove seen on the spiral ribs of that species. There is no other similar West Coast shell. One final species, originally named from “Pacosmayo, Peru,” which has been synonymized with Murexiella dip- sacus, is “Murex” peruvianus SowErRBY, 1841 [Proc. Zool. Soc. London, prt. 8, p. 147; Conch. IIl., plt. 195, fig. 103]. REEVE (1845) placed SowerBy’s species in synonymy with the neozealandic “Murex” octogonus Quoy & GaIMARD, 1833 (type of Murexsul), but this was refuted by SUTER (1918, p. 401). According to PonpErR (1968, p. 31) Mur- exsul octogonus is extremely variable, and if this is the case, then SowErRBy’s species probably is a synonym of M. octogonus. In any case, SowERBY’s shell certainly came from New Zealand and not from Peru for I have seen several New Zealand specimens that match his illustration exactly, complete with brown topped spiral ribs. If it is not the same as Murexsul octogonus then another name is necessary for there is an older Murex peruvianus, of Lamarck, 1816, a Trophon. Murexsul cuvierensts FINLAY, 1927, is probably the next available name. Page 328 Murexiella (Murexiella) keenae E. H. Vokes, spec. nov. (Plate 50, Figures 8 to 10) Shell large for the group, nature of protoconch unknown but probably 14 smooth, somewhat bulbous whorls; 6 whorls in adult teleoconch. Axial ornamentation on neanic whorls of 7 small varices, becoming from 5 to 7 heavy, ramose varices on body whorl. Spiral ornamentation of 2 strong cords on all whorls except the last, which has 6 and an additional 2 on the siphonal canal. Where spiral cords cross varices small recurved, fimbriate spines pro- duced, those on the canal slightly larger than on the remainder of the shell. Aperture circular, with a project- ing, almost entire peristome, broken only at the juncture of the siphonal canal. Outer lip strongly recurved, and marked by a series of laminae connecting the spines. Entire shell covered with minute scabrous growth lines and small spiral threads between the major cords giving a granulated appearance to the surface. Siphonal canal elongated, open, recurved at distal end, terminations of previous canals projecting as a series of spurs along a diagonal line to one side of the channel. Color ranging from peach to light brown, with dark brown blotches between the varices at the shoulder of the shell only; aper- ture white. In some specimens the tips of the varical spines a slightly darker color than the intervarical areas. Oper- culum muricoid with a basal (abapical) nucleus. Dimensions of holotype: height 34.3 mm; maximum dia- meter 22.5 mm. Holotype: Los Angeles County Museum of Natural His- tory no. 1259. Type locality: Venado Beach, Canal Zone (Venado Beach is just at the western boundary of the Canal Zone, ap- proximately 5 miles from the entrance to the Canal) ; Bay of Panama. Discussion: This species is more massive than any other species of Murexiella, either Pacific or Atlantic. Murexi- ella humilis may attain the same dimensions but has a much lighter appearance at the same size. The spines are shorter and more ramose in the new species than in M. humilis or M. norristi and the coloration is different, M. keenae having only a series of brown markings in the intervarical areas at the shoulder of the shell. These are easily seen in Plate 50, Figure 9. So far as is known the range of M. keenae is from the Bay of Panama north to Mexico. Dr. Keen informs me she has seen specimens taken by the shrimp fishermen in Mexican waters and in the collections of the American Museum of Natural His- THE VELIGER Vol. 12; No. 3 tory there is a specimen (no. 154654) dredged by the Puritan in 6 to 10 fathoms off the Tres Marias Islands, Nayarit. As was mentioned above, this is the species that was figured by KEEN (1958, figure 342) as “Maxwellia” hu- milis. It was also figured by Reeve (1845, plt. 13, fig. 50) as “Murex” humilis and that author noted: “This species has been but imperfectly described and figured hitherto for want of a good specimen. It is a species of very peculiar character, its pyriform growth, the curiously recurved bi-squamate structure of the varices, and its orange-red coloring are features of considerable specific interest.” However, the original illustrations of “Murex” humilis given by Sowersy (1834, plt. 65, figures 46, 47) are actually very well done and easily identified when compared with specimens. It gives me great pleasure to name this species in honor of Dr. Myra Keen, who has done so much for the study of West American Mollusca in general and the writer in particular. In addition, I would like to express my grati- tude to Mrs. Robert H. Stewart of Balboa Heights, Canal Zone, who collected the type specimen, and Mrs. Ben H. Purdy of San Diego, California, who provided the com- parative specimens of Murexiella humilis (including the one figured) for this study. There is another very fine specimen of M. keenae, from Venado Island, near Venado Beach, in her collection. Murexiella (Murexiella) laurae E. H. VoKEs, spec. nov. (Plate 50, Figures 4, 5) Shell small for the group; protoconch of 34 somewhat bulbous whorls, ending at a small varix; 6 whorls in adult teleoconch. Axial sculpture of 8 small varices on early whorls, gradually decreasing to 5 on later whorls of all specimens seen. Spiral ornamentation of 2 strong, square- topped cords on all whorls except last; on that whorl there are 5 cords on the body and 2 more on the siphonal canal. In the adult shells spiral cords completely obsolete in intervarical areas, visible only on abapertural side of varices. Where each spiral crosses the varices short, foli- aceous, recurved spines developed, and one additional spine between the suture and the shoulder spine, where no spiral is present. Spines connected by a complex web- bing formed by multiple laminae giving a fretted ap- pearance to the abapertural face of the varices. Aperture almost circular, slightly crenulated into the varical spines; no anal notch, columellar lip smooth, free-standing. Si- phonal canal moderately long, open by a narrow slit, Tue VE.IcER, Vol. 12, No. 3 [E. H. Voxgs] Plate 50 Figure 2 Figure 7 Figure 8 Figure g Figure to Vol. 12; No. 3 recurved at the distal end, bearing a series of spurs, which mark the previous terminations of the canal. Color a rich chestnut brown over entire shell, subsutural area only slightly darker. Operculum muricoid, with a basal nucleus. Dimensions of holotype: height 20.5 mm, maximum dia- meter 13.5 mm. Holotype: Los Angeles County Museum of Natural His- tory no. 1260. Type locality: Punta de Juluapan, Manzanillo, Colima, Mexico, 17 fathoms. Discussion: There are 8 specimens in the type lot of this new species, all collected by Mr. and Mrs. Carl Shy of Westminster, California. The species most nearly resem- bles the other new Murexiella described above but may be distinguished by its smaller size (both holotypes have 6 teleoconch whorls) and by the fact that the intervarical areas of M. laurae are completely smooth in contrast to the ribbed intervarical areas of M. keenae. The details of surface ornamentation are also different in the two species, M. keenae being covered with a microscopic gran- ular type of ornamentation while M. laurae is marked by a very fine pattern of crossed spiral and axial lines of equal strength, giving a woven cloth-like texture to the shell surface. Murexiella laurae differs from M. humilis in having more foliaceous varices, a smaller size, and again in the smooth intervarical areas. This new species is named in honor of Laura (Mrs. Carl) Shy, who so kindly contributed the type specimen. Five of the paratypes, the largest of which measures 23 mm in height, remain in her collection. One paratype is in the collection of Mrs. Ben H. Purdy, and one is in my collection, both through the courtesy of Mrs. Shy. I would also like to express my appreciation to Dr. William K. Emerson of the American Museum of Natural THE VELIGER Page 329 History who provided additional material for study and made several useful suggestions for the improvement of the manuscript. LITERATURE CITED BroperiP, WILLIAM JOHN 1833. Characters of new species of Mollusca and Conchifera collected by Mr. Cuming. Proc. Zool. Soc. London for 1832: 173 - 179 (14 January 1833) Emerson, WituiaM KeiTH « ANTHONY D?’ATTILIO 1969. A new species of Murexsul (Gastropoda) from the Gala- pagos Islands. The Veliger 11 (4): 324-325; plt. 50 (1 April 1969) Kren, A. MyRA 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Ponper, W. E 1968. | Nomenclatural notes on some New Zealand rachiglos- san gastropods with descriptions of five new species. Rec. Domin. Mus. 6 (4): 29 - 47; plts. 1-5 Reeve, Lovet, Aucustus 1845-1846. Conchologia Iconica; or Illustrations of the shells of molluscous animals. Monograph of the genus Murex. Lon- don, plts. 1 - 36 (April 1845 to April 1846) SoweErBy, GEorGE BRETTINGHAM (2%? of name) 1834-1841. Conchological illustrations. Murex. London, plts. 58-67 (30 May to 1 October 1834) ; plts. 187-199 (1 Janu- ary to February 1841), together with Murex: a catalogue of Recent species, 9 pp., London 1879. Thesaurus Conchyliorum: Monograph of the genus Murex. London, 4: plts. 380 - 403 Suter, HENRY 1913. Manual of New Zealand Mollusca. MacKay, Wellington, New Zealand, 1 - 1129; atlas of plates (1915) VoxEs, Emity Hoskins 1964. Supraspecific groups in the subfamilies Muricinae and Tritonaliinae (Gastropoda: Muricidae). Malacologia 2 (1): 1-41; plts. 1-3 (September 1964) Explanation of Plate 50 Figures 1, 2, 3: Murexiella (Murexiella) humilis (BRopERIP, 1833) Height 31.5 mm; maximum diameter 22.5 mm. Off Guaymas, Sono- ra, Mexico Figures 4,5: Murexiella (Murexiella) laurae E.H. Voxes, spec. nov. Holotype: Los Angeles County Museum of Natural History no. 1260. Height 20.5 mm; maximum diameter 13.5 mm. Punta de Juluapan, Colima, Mexico, 17 fathoms Figures 6, 7: Murexiella (Murexiella) diomedaea (Dat, 1908) Holotype: U.S.N.M. no. 123020. Height 29mm; diameter (ex- cluding spines) 16.0 mm. Gulf of Panama, 85 fathoms Figures 8, 9, 10: Murextella (Murexiella) keenae E. H. VoxEs, spec. nov. Holotype: Los Angeles County Museum of Natural History, no. 1259. Height 34.5mm; maximum diameter 24.0mm. Venado Beach, Canal Zone, Bay of Panama Note: In all figures (except nos. 2 and g) the specimens are whitened to show details of ornamentation (all figures X 2) Page 330 THE VELIGER Vol. 12; No. 3 Two New Epitoniidae from the Galapagos Islands (Mollusca : Gastropoda ) HELEN DUSHANE 15012 El Soneto Drive, Whittier, California 90605 (Plate 51) SPECIES OF Amaea are uncommon in the eastern Pacific Ocean with but three species having been described: Amaea brunneopicta (Datu, 1908), A. ferminiana (DALL, 1908) and A. tehuanarum DuSHANE & McLean, 1968. During the past months specimens of a fourth species of Amaea from the eastern Pacific have been sent to the author for identification. Comparison of these shells with photographs of Amaea (Scalina) retifera (DAL, 1889) in CLENCH & TuRNER, 1950, from the western Atlantic and with the holotpe (USNM 83733) of Da.u’s taxon sug- gests analogous affinity with the specimens from the east- ern Pacific; this taxon is here described. Amaea (Scalina) deroyae DUSHANE, spec. nov. (Plate 51, Figure 2) Description of Holotype: Shell medium in size, thin, pale brown, nuclear whorls missing in holotype; remain- ing 13 whorls strongly convex, with a round shoulder; suture deeply impressed, aperture subcircular; axial sculp- ture foliaceous with about 31 costae on the body whorl; costae scalloped, with high areas at the intersections of the spiral sculpture; 6 to 8 spiral ridges on the body whorl; this reticulate pattern is found on all whorls; within the reticulations are minute axial and spiral threads; basal area set off by a strongly projecting ridge and characterized by low but well-defined reticulate sculp- ture; columella short, terminating in a shallow sinus; outer lip thin, with about 7 crenulations, umbilicus. lack- ing; operculum missing in holotype. Dimensions: length 22.8 mm, width 7.3 mm (holotype). Type Material: Holotype: Los Angeles County Museum of Natural History; LACM-AHF 147-34, Invertebrate Zoology Type Collection, catalog number 1236 Paratypes (5): Los Angeles County Museum of Natu- ral History; LACM-AHF 147-34, Invertebrate Zoology Type Collection, catalog numbers 1239, 1240, 1241, 1242, 1243 Paratypes (2): The American Museum of Natural His- tory; AMNH number 152604 Paratypes (2) : The American Museum of Natural His- tory; AMNH number 152605 Paratype (1): Mrs. Jacqueline DeRoy collection Type Locality: Tagus Cove, Isla Isabela (Albemarle Is- land), Galapagos Islands, Ecuador, 0°16’S Lat., 91°22’ W Long., 6 specimens dredged by the Velero III at sta- tion AHF 147-34, in 30 fathoms, rock and coral bottom, 13 January 1934. Five additional specimens were dredged by Mrs. Jacqueline DeRoy at the same locality in 35 to 60 fathoms, 27 January 1968. Additional Localities: Five specimens in the Santa Bar- bara Museum of Natural History Collection and one in the DuShane Collection, referable to this taxon, were trawled off Cabo Haro, Guaymas, Sonora, Mexico, 27°52’ N Lat., 110°52’ W Long., in 45 to 90 fathoms, 2 Sep- tember 1960. Two additional specimens in the Shasky Collection were trawled off the west side of Isla Monser- rate, Gulf of California, Mexico, in 20 to 40 fathoms, 1 September 1960. One worn specimen in the Shasky Col- lection was dredged off Punta Final, Gulf of California, Mexico, in 20 fathoms, January 1961. Two specimens in the American Museum of Natural History Collection were dredged off Maria Magdalena Island in the Tres Marias Islands group on the Puritan-American Museum Expedi- tion, in 28 fathoms, March 1967. A third specimen in the American Museum of Natural History Collection was dredged off the southwest side of Isla San Diego, Gulf of California, 25°11’30” N Lat., 110°42’40” W Long., on the Puritan-American Museum Expedition, in 25 to 40 fathoms, 30 April 1957. This specimen appears to be freshly dead. THE VELIcER, Vol. 12, No. 3 [DuSuane_E] Plate 51 Figure 1 Figure 2 Figure 1 Epitonium (Nitidiscala) hancocki DUSHANE, spec. nov. Holotype: Hood Island, Galapagos Islands, Ecuador. Length 13 mm Photograph X 4; courtesy Los Angeles County Museum of Natural History Figure 2 Amaea (Scalina) deroyae DUSHANE, spec. nov. Holotype: Tagus Cove, Albemarle Island, Galapagos Islands, Ecuador. Length 22.8mm. Photograph X 1.2; courtesy Los Angeles County Museum of Natural History Vol. 12; No. 3 THE VELIGER Page 331 Table 1 Shell Measurements of Amaea (Scalina) deroyae spec. nov. 6 q § 8 gf 4: fas rr g god FS Locality Zan AAS S) Los Angeles County 6 22.8 X 7.3 14 Isla Isabela, Galapagos Islands, Ecuador Museum - Allan 14 x5 13 Hancock Foundation 13 xX 4 13 specimens 8 X3 10 6 X2 10 Sieowe 9 American Museum 2 16.5 X 5.5 16 Isla Isabela, Galapagos Islands, Ecuador of Natural History 13. X 4.5 14 (152604) American Museum 2 5 X2 6.5 Maria Magdalena Island, Tres Marias of Natural History 3.8 X 1.5 8 Islands, Mexico ((67 : 75204) Puritan-American Museum Expedition American Museum 1 14 xX4 13 Isla San Diego, Gulf of California, of Natural History Mexico (76220) Puritan-American Museum Expedition Santa Barbara 5 20 X75 14 Cabo Haro, Gulf of California, Museum of Natural 13 xX 4 13 Mexico History 12 x3 13 2.5 X 1.3 6 2 X08 5 Dr. Donald Shasky 2 10 x3 13 Isla Monserrate, Gulf of California, Collection 9 X25 10 Mexico Dr. Donald Shasky 1 45 X 1.5 9 Punta Final, Gulf of California, Collection Mexico DuShane Collection 1 19 X65 14 Cabo Haro, Gulf of California, Mexico Discussion: Amaea deroyae appears to be an analogue of the Caribbean species A. retifera (Dai, 1889) (CLENCH & TURNER, 1950; p. 243; plts. 96, 106, figs. 1 to 4). Dax, 1902; plt. 30, fig. 9, and Datz, 1903; plt. 76, fig. 9 present good drawings of the holotype of A. retifera. Amaea deroyae has the same sculptural charac- ters, but its shell is apparently consistently smaller than that of the Atlantic species. The Atlantic specimens attain a maximum height of about 30 mm, although the holo- type is 13mm; whereas the largest Pacific specimen measures 22 mm. None of the Pacific shells seen were taken alive. CLENcH & TuRNER (1950, p. 245) describe the opercu- lum of the Atlantic species; they give the range for A. retifera as North Carolina to Florida, the Gulf of Mexico and south to the Barbados, in from 13 to 120 fathoms, with 50 fathoms being the median. It is a relatively abundant species as indicated by the records presented by CLENCH & TuRNER (I. c.) They compare Amaea reti- fera with A. decussata (LaMaRcK) from the East Indies, suggesting the relationship to be very close. Amaea deroyae is known to range throughout the Gulf of California, and to occur off the Tres Marias Islands and the Galapagos Islands. The name honors Mrs. Jacqueline DeRoy of Isla Santa Cruz, Galapagos Islands, Ecuador, an avid collector, who continues to contribute to our knowledge of the Galapagan fauna. The other epitoniid is a remarkable new species that is referable to the subgenus Nitzdiscala. Page 332 Epitonium (Nitidiscala) hancocki DUSHANE, spec. nov. (Plate 51, Figure 1) Description of Holotype: Shell white, glossy, axial costae 21, continuous from whorl to whorl, with a sharp spine at the shoulder of each whorl; nuclear whorls 3, smooth, convex, brown, glassy; post nuclear whorls 9; suture deeply impressed ; umbilicus small, not hidden by parietal lip; surface area between costae lacking spiral threads, whorls rounded; basal cord lacking; aperture oval; outer lip reflected and formed by the last costae; operculum thin, paucispiral, yellowish brown in color. Dimensions: length 13.0mm, width 5.2 mm (holotype). Type Material: Holotype: Los Angeles County Museum of Natural History; LACM-AHF 814-38, Invertebrate Zoology Type Collection, catalog number 1235 Paratype (1): Los Angeles County Museum of Natural History; LACM-AHF 802-38, Invertebrate Zoology Type Collection, catalog number 1238 Paratype (1): Mrs. Jacqueline DeRoy Collection Paratypes (2) : DuShane Collection Type Locality: North of Hood Island (Isla Espamola), Galapagos Islands, Ecuador, 1°21’S Lat., 90°40’ W Long., one live-taken specimen dredged by the Velero III at sta- tion AHF 814-38, in 20 to 40 fathoms, shell bottom, 28 January 1938. One additional specimen dredged north- west of Isla Santa Maria (Charles Island), Galapagos Islands, Ecuador, 1°09’S Lat., 90°35’ W Long., by the Velero III at station AHF 802-38 in 250 fathoms, sand and shell bottom appears to be the same species although badly broken; 4 whorls remain. One live-taken specimen was dredged in 55 fathoms off the north end of Isla Santa Cruz (Indefatigable Island) , Galapagos Islands, Ecuador, 25 November 1967 and two specimens were dredged in 112 fathoms off the north end of the island in 1969 by Mrs. Jacqueline DeRoy. Discussion: Epitonium hancocki differs from all: other epitoniids known from the west coast of the Americas by having a tabulate outline, many costae and a glassy ex- terior. From Epitonium (Asperiscala) kelseyi BaKer, Hanna & Stronc (1930), which it most resembles, it differs by having no spiral sculpture and by having a thinner shell. From E. implicatum Dati «& OcHSNER (1928) (fossil, probably Pliocene) it differs by having THE VELIGER Vol. 12; No. 3 more costae, a sharp spine at the shoulder of each whorl and a small umbilicus. This Epitonium is named in honor of the late Captain G. Allan Hancock who, with his oceanographic research vessel, Velero III, undertook numerous expeditions to the tropical eastern Pacific, including the Galapagos Islands, where specimens of this new species were obtained. ACKNOWLEDGMENTS I am indebted to Dr. William K. Emerson for critical evaluation of the manuscript and to the Los Angeles County Museum of Natural History for photographs. For the loan of the holotype of Amaea (Scalina) retifera I am grateful to the United States National Museum. LITERATURE CITED Baker, FREDERICK, G DaLLas HANNA & ARCHIBALD M. STRONG 1930. | Some Mollusca of the family Epitoniidae from the Gulf of California. Proc. Calif. Acad. Sci., ser. 4, 19 (5): 41 - 56; plts. 2, 3 (15 July 1930) CiencH, WILLIAM JAMES & RuTH Dixon TURNER 1950. The genera Sthenorytis, Cirsotrema, ... in the West- erm Atlantic. Johnsonia 2 (29): 221-248; plts. 96 - 107 Mus. Comp. Zool., Harvard Univ. (30 September 1950) Dati, WILLIAM HEALEY 1889. Reports on the results of dredging, .. . in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U. S. Coast Survey Steamer “Blake”, .. . Report on the Mollusca, pt. 2, Gastropoda and Scaphopoda. _ Bull. Mus. Comp. Zool. 18 (2): 1 - 492; plts. 1 - 40 1902. _ Illustrations and descriptions of new, unfigured, or im- perfectly known shells, chiefly American, in the U.S. National Museum. Proc. U.S. Nat. Mus. 24: 499 - 566; plts. 27 - 40 1903. A preliminary catalogue of the shell-bearing marine mol- lusks and brachiopods of the southeastern coast of the United States, with illustrations of many of the species. Reprint, to which are added 21 plates not in the edition of 1889. Bull. U.S. N. M. 37, new ed.: 232 pp., 95 plts. (3 April 1903) Dati, WILLIAM HEALEY & WASHINGTON HENRY OCHSNER 1928. Tertiary and Pleistocene Mollusca from the Galapagos Islands. Proc. Calif. Acad. Sci. ser. 4, 17 (4) : 89 - 140; plts. 2-7; 5 text figs. (22 June 1928) Fraser, C. McLean 5 ; 1943. General account of the scientific work of the Véelero III in the eastern Pacific, 1931-41. Part III. A ten-year list of the Velero III collecting stations (charts 1 - 115). Allan Hancock Pac. Exped. 1 (3): 259-431. Univ. South. Calif. Press, Los Angeles, Calif. Vol. 12; No. 3 THE VELIGER Page 333 An Ecological Study of Valley-Forest Gastropods in a Mixed Mesophytic Situation in Northern Kentucky ' BRANLEY A. BRANSON DONALD L. BATCH Eastern Kentucky University, Richmond, Kentucky 40475 (7 Text figures; 3 Tables) INTRODUCTION THE MOLLUSCAN FAUNA of Kentucky is poorly understood (BickEL, 1967), practically nothing having been written concerning the ecology of terrestrial species. Aquatic forms are even more poorly known. The objects of this report, then, are to present the findings of an ecological study carried out in a rather typical Cumberland Plateau val- ley system, attempt a correlation between mollusks present and Horton’s (1945) valley classification as modified by KueuHne (1962), record data which will be useful in determining the changes that occur as habitat disruption proceeds, and to compare the faunas of disturbed versus undisturbed areas. A possible criticism of a portion of the study, i. e., that each station was only visited one time and hence during cold periods snails would be in hibernation whereas during warm months they would be active, is negated by the randomness and intensiveness of our collecting method. Furthermore, the authors do not confuse the concept of habitat and niche. Historical Review of Studies on Kentucky Gastropods As indicated by BickEt (1967), almost all of the knowledge extant concerning Kentucky mollusks has been gleaned by workers outside the state. This is especially true in the case of snails. During the nineteenth century, Thomas Say and ' Supported by Eastern Kentucky University Faculty Grant 5-3- 372-6 Rafinesque contributed periodic lists and descriptions, mostly from the Ohio River Drainage. A few other wor- kers, notably Lea, described new species. During this cen- tury, very little has been accomplished. BickEL (1965, 1966) conducted some brief ecological studies on some aquatic species. CLENCH (1926, 1962a, 1962b) and CLencH & TuRNER (1955) have presented significant findings in aquatic species, as have RosEwaTER (1959) and Price (1900). The latter paper also contained infor- mation on terrestrial species. Because of the extensive studies of GoopricH (1921, 1929, 1934a, 1934b, 1934c, 1937, 1938, 1940, 1941), no fauna is better understood than the aquatic pleurocerids. However, in terrestrial species, excluding the assorted records appearing in PrtsBry’s monograph (1939 - 1948), only Conkuin (1957), Husricut (1950, 1958a, 1958b, 1960, 1962a, 1962b, 1963a, 1963b, 1963c, 1964a, 1964b) and KapLan & MINCKLEyY (1960) have made any attempt to study the diverse fauna of Kentucky. None of these works bears directly upon ecology. History and Description of the Area The deeply dissected, highly dendritic canyon system chosen for the study lies in the Cumberland Plateau of Wolfe and Powell Counties, Kentucky (Figure 1). The valley floors are mostly underlaid by undifferentiated Mississippian rocks, whereas the dissections themselves are through much-interdigitated Lee Sandstone under- laid by Breathitt formation. The latter formation is ex- posed on the floors, and it consists mostly of gray mica- careous siltstones, subgraywacke sandstone, dark and light claystones containing ironstone concretions, some lime- stone (very sparse), chert, and coal (BRANSON & BatcH, Page 334 Byartee sequre 7 sea roa Sy PTO recat eas ay Figure 1 Map showing the Position of Wolfe and Powell Counties, Kentucky. 1968). The rugged, narrow valley with steep cliffs is supported by this formation. The overlying Lee Formation produces even more massive cliffs, 200 to 300 feet high (flat-faced and vertical), consisting mostly of resistant sandstone and siltstone, relatively little clay, ironstone, and limestone being in evidence. The canyon system heads approximately 4/5 of a mile northwest of Pine Ridge, Wolfe County (Figure 2). The three main canyons were sampled, but the numerous side systems were not. The Tight Hollow system, consisting of first, second, and third order canyons, drains 0.558 square mile, and it is three-pronged, roughly Y-shaped. The south arm, which receives a short, deep bifurcation, heads at 1040 feet mean sea level (msl), and extends 2.4 miles to its confluence with the north arm. The head- water cliffs average slightly more than 200 feet in vertical height. Below this point, the cliffs are of variable height, THE VELIGER Vol. 12; No. 3 but always steep, and the enclosed valley is narrow and rocky. The northern arm heads at 1240 msl, then extends two miles to its confluence with the southern or lower one at 1030 feet. From this point, the lower arm extends 2225 feet to make contact with the Mill Creek system at 900 feet msl. Mill Creek meanders between steep walls for slightly in excess of 12000 feet to open into the much wider canyon of the Middle Fork of Red River, picking up Doe Branch, Black John Creek, and Doublecave Branch en route. The floor of these canyons is occupied by spring-fed perennial streams (see “collecting station” notes). Table 1 presents the physical and chemical characteristics of the streams. In Tight Hollow, the creek is small, ranging from 4 to 6 feet in width and from 1 to 6 inches (excluding a few pools) in depth at the headwaters. In the second order stretch, the creek widens to about 15 feet and ranges from 8 inches to 3 feet in depth. Below station 4, the creek runs in a bed averaging 30 feet in width, but the actual water course ranges from 30 inches to 15 feet, mostly very shal- low, clear water. At the point where stations 4 and 5 join, there is a large pool of approximately 30 feet in diameter, 14 feet in depth. In the third order canyon, the stream averages 20 feet in width, 3 to 4 inches in depth, with pools up to 3 feet deep. Numerous small springs join the stream in this stretch, and the stream bed drops rapidly, about 12 feet in 30 linear feet. At the lower end of this station, there is a pool approximately 40 feet in diameter, and about 44 feet deep, above which is a small waterfall. Below station 6, the stream is about 20 feet wide and varies from 6 to 12 inches in depth. The portion of Mill Creek occupied by station 8 aver- ages 12 feet in width and about 2 feet in depth. In the stretch designated as station 9, the stream has a tendency to become braided in places, but in general the channel averages about 17 feet in width and ranges from 3 inches to 3 feet in depth. Station 10 contains a rapidly dropping bed, and Mill Creek widens to about 30 feet, alternating between 2-foot pools and shallow riffles. Most of station 11 is occupied by Mill Lake (Figure 2). Above the lake, the stream is 25 to 30 feet wide and 14 inches deep, where- as at the earth-fill dam it is 65 feet deep. The remaining 3 stations are in the fourth order canyon of Middle Fork of Red River. Here, the stream ranges from 30 to 50 feet in width and from 6 inches to 4 feet in depth. The stream bottom in Tight Hollow consists of flat sandstone, deposits of sand, some organic debris, and sandstone boulders. In the Mill Creek canyon, the bottom Vol. 12; No. 3 THE VELIGER Page 335 >) N Natural /, 4 Bridge f vis 13 II RS NS) a o% cy 5 9% & 4,4, : : Vy * Ill 12 ” , 7 10 IV 8 I _ a 0.5 mile Figure 2 Map showing the Position of Collecting Stations in Tight Hollow, Mill Creek, and Red River Canyons, Wolfe and Powell Counties, Kentucky. Arabic numerals demark stations; Roman numerals indi- cate canyon-stream order (Horton System). Collections made midway between arrows (see text). is primarily flat sandstone, small boulders, and large amounts of sand. The Red River bottom consists primarily of sand, gravel, and medium to small rocks, except at station 14, where large quantities of mud have accumu- lated. Some of the general biotic conditions of these canyons were indicated by BRANSON & BatcH (1968, 1969, and in press). The upper part of the system has never been occupied by man, notwithstanding a few abortive at- tempts to locate silver there at the tum of the century. Conditions are essentially relict and unmodified from, and including stations 1 through 5. The dominant trees are beech, eastern hemlock, tulip tree, red maple, northern dogwood, and umbrella magnolia on the south ridge; American holly is abundant from station 6 upgrade. From station 1 through 5, Rhododendron is exceedingly dense, _up to 2117 main stalks per acre. Below station 5, the lat- ter form is progressively replaced by mountain laurel. A similar relationship exists between hemlock and tulip trees, and hemlock versus pines (White and Virginia). These conditions reflect the effect of commercial logging some 20 years ago. Below station 5, the valley has been logged, and at the junction of stations 7 and 8 the remains of an old farm are visible. Ecological conditions on this point are best described as old field. Below Mill Lake, which is a trout-stocked fishing lake, Red River stations 12, 13, and 14, lie in the much-dis- turbed Natural Bridge State Park. Thousands of fishermen, campers, hikers and picnickers visit the area annually. Of the ground vegetation, various species of Polypodi- aceae, Sedum, Lygodium, Lycopodium, and numerous mosses are the most important in the undisturbed upper stations, with some dense stands of Equisetum along the creek, and thick growths of Mitchella repens LINNAEUS, 1756, on the drier slopes. Downstream, several grasses have invaded the clearings, and Salix grows luxuriantly along Page 336 the stream margin. In the undisturbed areas, there is a thick litter of leaves and needles, in addition to many logs and limbs in various stages of decomposition. Other than a little encrusting algae, there is no aquatic vegetation in the stream until Mill Lake is formed. There, a meagre growth of Nitella occurs in deep water, and sparse accu- mulations of Spirogyra elsewhere. Below the lake in Red River, the bottom is without rooted plants until station 14 is reached. As indicated above, the bottom at this station has considerable mud, and in backwaters considerable growths of Typha angustifolia LINNAEUS, 1756, and Pota- mogeton crispus LINNAEUS, 1756 occur. METHODS Field sheets and notes were prepared for each station, which included general descriptions, field numbers, and the material included in Table 1. The latter data were secured by means of tests included in “Standard Methods for the Examination of Water and Wastewater” (ORLAND, 1965). Turbidity was determined by means of a Hellige Turbidimeter, and water color was assayed by the plat- inum-cobalt method (Lamar, 1949). At each of the collecting stations delineated in Figure 2, a 12-foot wide swath, located at the center of each station, was hand-collected from one rim of the valley to the other. Fine-pointed forceps were utilized to secure small to THE VELIGER Vol. 12; No. 3 minute specimens, and in some areas a set of graduated brass sieves were used to sift litter. Information on plant associations was obtained by means of random swaths. COLLECTING STATIONS Collections were secured from 14 sites. In the text follow- ing, specimens are referred to proper stations by numbers in parentheses. All specimens, unless otherwise indicated, are deposited in the Eastern Kentucky University Museum of Zoology. Station 1. 26 February 1966. Valley narrow, V-shaped, between vertical, concave cliffs which rise over 200 feet; several old talus slides present; all boulders and rocks are sandstone with some small nodules of iron- stone. Numerous fallen logs present. Vegetation dense, including mosses, liverworts, ferns; heavy shade by Tsuga, Magnolia, Rhododendron, and Ilex. Much ground seepage. Creek 4 to 6 feet wide, clear, running over bedrock, rubble, boulders, and sand, 1 to 14 inches in depth, with a few shallow pools up to 2 feet in depth. Modest current. Station 2. 5 March 1966. Valley narrow, V-shaped, the floor heavily littered with massive boulders, flat sand- stones, and some topsoil washed in from above; forest litter deep and humid. Other conditions and vegetation approximately as at station 1. Creek varies from 6 to 15 Table 1 Physical and Chemical Data for Tight Hollow Creek, Mill Creek, and Middle Branch of Red River, Wolfe and Powell Counties, Kentucky (all temperatures in degrees Centigrade) Station Number 1 2 3 4 5 Hydrogen Ion conc. (pH) 6.98 7.05 7.08 6.85 7.10 O, (ppm) 10.74 11.46 1085 10.93 11.12 % Saturation of O, 80 88 87 97 91 Free CO, (ppm) 0.85 0.50 Phenolphthalein 0 0 0 0 0 Methyl Orange 1720) 16:83) eli, 111883) 7275 Hydroxide 0 0 0 0 0 Carbonate 0 0 0 0 0 Bicarbonates VLOGS Siilel/eem eS Smee Hardness (Total: Ca & Mg) 52.97 41.54 2669 36.32 19.57 Air Temperature (°C) 2 a) lk 10.05 10.0 Water Temperature (°C) 1.8 3.7 5 9.0 5.8 Soil Temp. (6” depth, °C) 3.0 5.0 6.0 7.5 6.0 Turbidity (ppm) se — 4:25) 43.3) 7.33 Color (ppm) — — — — 15.5 6 7 8 9 10 11 12 13 14 6.91 7.16 698 7.01 656 7.09 7.51 7.27 7.52 10.78 10.97 872 878 818 9.02 878 9.25 8.37 92 91 90 — aS} IG) 0.37 043 0.75 033 030 047 0.00 020 0.57 0 0 0 0 0 0 1.83 0 0 9.75 25.17 11.75 17.83 24.17 42.83 57.33 65.33 43.0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 0 3.67 0 0 9.75 25.17 11.75 17.83 24.17 42.83 55.50 65.33 43.0 14.93 23.68 18.97 26.49 31.23 46.15 259.42 254.14 158.27 10.75 78 197 — Pils) a) BA YAO) af) 2 7.0 60 16.0 — 19.0 285 27.0 285 285 7.0 60 160 — 11.5 — 17.0 225 — 10) 3H} ee) AO) 0.77 036 O41 1.23 1.53 15.5 100 250 <5.0 <50 <5.0 <50 <50 <5.0 Vol. 12; No. 3 feet in width, with several small cataracts over boulders (lacking in late summer) and a few pools up to 20 feet in diameter and 2 feet in depth; bottom of sand, boul- ders, and flat rock impregnated here and there with small white nodules; heavily overhung by Rhododend- ron, and several dead Tsuga logs have fallen into the stream from the steep sides. Station 3. 12 March 1966. Cliffs less declivitous; valley U-shaped, now with a narrow flood plain containing much organic debris. Vegetation and other conditions similar to those of previous two stations. Creek, slightly meandering over bed of sandstone, rubble, small boul- ders, logs and debris, undercuts the cliffs in places, and some of the banks have fallen into the stream; alter- nation of shallow riffles with pools (2 to 3 feet in depth; one 50 feet in length), and a 4-foot fall is located near the center of the station. At lower end of the station, the valley again assumes its narrow char- acter; stream bed inclines at a steeper angle, and widens to approximately 30 feet. Two small springs join the main stream at this point. Station 4. 19 March 1966. Slope of valley walls less steep than at station 3. A modest flood plain of gravel, mud, sand, large and small sandstones, and deep organic litter, from 50 to 100 feet in width attends the stream. Stream bed about 30 feet wide, the flowing water from 24 to 5 feet in width, alternating between riffles (some 100 feet long) and pools, flowing over slightly terraced bedrock; much bank undercutting; a 10-foot fall in lower 4 of station. Vegetation much the same as at previous stations. Station 5. 26 March 1966. Nearly identical with station 4. Rhododendron forms canopy above water. Small amounts of algae in the stream. At the point where stations 4 and 5 meet, a pool 30 feet wide, 14 feet deep, and 150 feet long is produced. Station 6. 2 April 1966. Valley wider at this point, and the slope of its walls more gentle; Tsuga partially re- placed by white pine, and Rhododendron by Kalmia; forest floor more open with less litter. Stream averages 20 feet in width; bottom of bedrock roughed by numer- ous terraces, set at right angles to long axis, 2 to 12 in- ches in height; there is an alternation of sandbottomed pools and riffles; numerous springs fall into the stream. Below the middle of the station the stream bed declines rapidly, about 12 feet in a 30-foot stretch, and the bed- rock contains many washed-out holes; near the lower end, the drop is about 17 feet in 100. At the point denoted by the lower arrow in Figure 2, a nearly circular pool has been gouged out. It is about 40 feet in diameter, has a sloping sand bottom, and is 44 feet THE VELIGER Page 337 in depth. The pool discharges via a short, straight chan- nel over a 5-foot fall. Station 7. April 1966. Similar to station 6, but valley reverts to the V-shaped configuration with vertical walls. Much dead wood, logs, and sandstone rubble and boulders. Considerable ironwood, beech, black alder, and red maple present; practically no Rhododendron. In the lower 4 of the station, the stream goes under- ground for approximately 30 feet before emerging. Near the end of the station, the stream again submerges, runs underground for nearly 200 feet, and finally percolates up through sand and gravel to form a pool 4 feet deep, 55 feet long, and 12 feet wide. At the end of the station (confluence with Mill Creek), the valley widens ab- ruptly, and a substantial flood margin is produced. On the left bank, and also partially adjoining Mill Creek, there is an old field sere, bearing numerous weedy plants, sumac, willow, young pine, cedar, Lobelia, and some other flowering plants. Station 8. 23 April 1966. Mill Creek Valley. Valley wide, the slope of its walls moderate, with a flood plain of 200 to 300 yards in width gently inclined towards the creek; it is covered by grasses, sedges, sumac, various weedy species, dogwood, and a few maples. There are some boulders, small stones, rubble and organic silt. The creek, averaging 12 feet in width, runs in a bed of bedrock, rubble, sand, and gravel. Near the upper end of the stream, there are several oxbows, 2 to 5 feet in depth, with mud bottoms and weedy banks with numerous willows. Station 9. 14 May 1966. Valley continues to widen, its walls to become lower. Evidence of an old silver mine on the left, about 100 yards downstream from the sta- tion’s upper end. Flood plain similar to that of station 8. Stream about 7 feet wide, 3 or 4 inches deep, flowing over bedrock, gravel, sand, and small boulders. About 200 yards downstream, a large spring wells into the channel from the south bank. Below this, there are some large sandstone deposits along the south bank, and the channel tends to become braided. Station 10. 22 May 1966. Essentially similar to station 9, but valley wider. In places, there are deposits of dead leaves and soil beneath 50-foot cliffs. Stream 20-foot wide, 3 to 18 inches deep, running over bedrock, sand, and gravel, alternating between pools and riffles at lower end. Station 11. 25 June 1966. Valley impounded, mostly filled by Mill Lake. Around the margins of the lake are many dead trees, standing and fallen, and the early stages of succession are visible. Otherwise, the condi- tions are similar to those at station 9, although the Page 338 valley is somewhat deeper and narrower. Above the lake, the stream bottom is of sand, and the water is about 25 to 30 feet in depth. At the point where the stream widens out into the lake, the bottom possesses much dead organic matter, and methane gas continu- ously bubbles up from the bottom. The lake is 65 feet deep at the dam. Living trees around the dam are mostly tulip trees, sycamores, sumac, and hawthorne. Station 12. 11 June 1966. Middle Fork of Red River Valley. Valley much wider and, in places, the flood plain is nearly a mile wide. Agriculture practiced (mostly corn and tobacco), with numerous examples of old field succession: grasses, sedges, mullein, and weedy species. Dominant trees are willow, sycamore, tulip, hawthorne, some White and Virginia pine, and a few young Tsuga. The area is much disturbed. The river varies from 20 to 30 feet in width, with pools 3 feet in depth, and long stretches of six-inch water running over gravel, sand, small rocks, and beer cans. Station 13. 2 July 1966. Valley approximately 1 mile in width, with a flood plain of approximately 80 feet on each side of the stream. General vegetation like that at station 12, but with large accumulations of dead leaves and drift-deposited twigs and limbs. Stream 20 to 40 feet in width, 2 to 7 feet deep; side pools contain mud, dead leaves. and organic ooze. The station ends in a sand-bottomed pool about 3 feet in depth, 45 in width, and 200 feet in length. Station 14. 9 July 1966. Valley conditions similar to those at station 13, but trees more numerous: black walnut, willow, white pine, ash, box elder, dogwood, redbud, hawthorn. River banks heavily overgrown by Kudzu. Stream 30 to 50 feet wide, 24 to 4 feet deep, running over sand, mud, and gravel. A low-water dam is placed at the upper end of the station (Figure 2), below which is a pool about 50 feet in diameter; its bottom is mostly muck, and along the sides are good growths of Potamogeton, Carex, Spirogyra, and narrow-leafed cattail. Accounts of Species A total of 1703 specimens was secured from the 14 sites delineated above. Represented in the collections were 12 families, 26 genera, and 52 species; two species are ap- parently new. These are described (not named) below. In the list which follows, the first numeral presented is the station designator; the numbers in parentheses repre- sent the number of specimens collected at each site. THE VELIGER Vol. 12; No. 3 PoLyYGYRIDAE Members of this family, represented by 3 genera and 14 species, accounted for 47.26% of the total collections, and it is thus the dominant molluscan taxon in the area, being approached only by the Zonitidae. Of the total collection, Stenotrema comprised 15.03%, Mesodon 23.67 %, and Triodopsis 8.57%. These data are broken down further in Table 2, and additional analysis is presented in the discussion. This pattern is adhered to throughout the paper. Table 2 Percentage-Composition by Polygyrid Species in a Northern Kentucky Faunule % of total Species fauna Stenotrema evardsi (BLAND, 1856) 4.34 Stenotrema stenotrema (PFEIFFER, 1842) 5.46 Stenotrema angellum Husricut, 1958 0.05 Stenotrema barbatum (Cxapp, 1904) 3.75 Stenotrema leat (BINNEY, 1840) 1.17 Mesodon thyroidus (Say, 1816) 1.52 Mesodon zaletus (BINNEY, 1837) 0.05 Mesodon appressus (Say, 1821) 5.81 Mesodon sayanus (Pirssry, 1906) — 5.51 Mesodon ruglei (SHUTTLEWoRTH, 1852) 10.74 Triodopsts tridentata (Say, 1816) 3.69 Triodopsis fraudulenta (Pitssry, 1894) 1.93 Triodopsis denotata (Férrusac, 1821) 0.82 Triodopsis albilabris (Say, 1816) 2.11 Stenotrema evardsi (BLAND, 1856) Collecting sites: 1(1), 2(3), 3(1), 4(2), 5(24), 6(6), 7(5), 8(6), 9(15), 10(6), 12(1), 14(4) This Appalachian snail characteristically occupies habi- tats along stream margins, valley slopes and mountains, mostly at elevations greater than 750 feet (ARCHER, 1948). Most of our specimens were found under decaying wood and in leaf litter. The species was more abundant in the middle and lower valleys than in the narrow portions above station 5 (0.9% to 2.56% from station I through station 4; 4.81% to 15.38% from station 5 through station 11). Below station 11 there was a sharp drop in numbers (1.78% to 3.33%). These latter stations have been grossly disturbed, so this may not be a valid observation. On the other hand, the altitude at the lower end of the study area is approaching the lower limits of Stenotrema evard- s?s altitudinal distribution. Vol. 12; No. 3 Stenotrema stenotrema (PFEIFFER, 1842) Collecting sites: 1(3), 2(6), 4(7), 5(7), 6(5), 7(10), 8(3), 9(27), 10(5), 11(7), 12(2), 13(2), 14(9) Stenotrema stenotrema is a rather plastic species as regards habitat. We secured it in all sorts of places — beneath decaying hardwood and softwood logs, under bark, in leaf litter, beneath rocks — and at all altitudes. In the upper (excluding station 2) and middle stations, the population varied between 2.91% and 6.79%, reaching a higher percentage at and below station 9, 7.29% to 9.63%. Stenotrema angellum Husricut, 1958 Collecting site: 12(1) The single specimen was found beneath a pile of dead bark near a tulip tree on a bluff above the stream. This is essentially the same type of habitat from which Hus- RICHT (1958) removed the holotype. He (loc. cit.) indi- cated that the species was often found with S. stenotrema. However, in collections from other localities, we have found S. angellum only on the lower slopes, whereas S. stenotrema is often found at higher elevations as well. Stenotrema barbatum (Ciapp, 1904) Collecting sites: 1(1), 2(1), 3(5), 4(2), 5(3), 6(11), 7(24), 9(7), 10(3), 11(6), 12(1) This species was entirely restricted to the lower sides of the slopes, where it was found under leaf litter, decaying wood, and to a less extent, under loose talus. It is difficult to compare our findings in this area with those secured elsewhere because of taxonomic confusion between this form and Stenotrema hirsutum (Say, 1817). This latter is a smaller species, usually between 6.3 and 6.8mm in diameter, lacking a buttress on the shell. All our speci- mens are larger than 6.9 mm (6.9 - 9.0 mm) in diameter, and all possess a buttress. From station | through station 5, except at station 3, Stenotrema barbatum comprised only 9.97% to 1.92% of the molluscan fauna. At station 5, where the valley immediately re-assumes its narrow character, the popu- lation percentage drops to 1.92%. At the middle stations, 6 through 11, the percentage composition ranged from 4.68% to 9.64% (average 7.49% ). In the lower 3 stations, more or less disturbed, the species represented less than 2% of the total population, or was replaced by the next species. Stenotrema leai (BINNEY, 1840) Collecting sites: 4(3), 6(1), 7(8), 9(6), 11(2), 13(1), 14(3) Essentially a species of lowland hardwood forests, al- though sometimes found in coniferous situations, this species has a rather high moisture requirement and is THE VELIGER Page 339 thus limited to stream margins up to around 800 feet elevation. Bascu, BaINER & WitHM (1961) and others have found the snail in similar situations. The lowlands affinities of Stenotrema leai are well-illustrated by these findings. With the exception of station 4, where a small- pocket population exists, the snail is completely lacking in the upper stations (elevations above 1000 feet). From stations 7 through 14, S. leai comprised from 2% to 3% of the total terrestrial gastropod population. Mesodon thyroidus (Say, 1816) Collecting sites: 9(7), 11(16), 13(7), 14(6) Pitssry (1940) indicated that Mesodon thyroidus was a lowland species, usually occupying humid habitats below 650 to 700 feet (occasionally up to 900 feet), and the ob- servations presented here bear out the premise. Our spe- cimens were either removed from leaf litter or found beneath decaying logs. In the lower valleys, M. thyroidus makes up between 3.5% and 6.25% of the fauna. Mesodon zaletus (BINNEY, 1837) Collecting site: 14(1) Although station 14 is a lowland site, this probably does not reflect an altitudinal preference. Prtspry (1940) found Mesodon zaletus up to 2000 feet above sea level in the southern Appalachians. Since the Lee Formation is very deficient in calcium, the absence of M. zaletus in most of this region probably reflects the lack of shell-building materials, The species is more or less abundant in regions to the south and west of the Upper Red River Drainage, and in the lower part of the drainage itself. Mesodon appressus (Say, 1821) Collecting sites: 1(2), 2(7), 3(5), 4(12), 5(6), 6(10), 7(9), 8(3), 9(21), 10(5), 11(11), 12(2), 14(6) According to Pitssry (1940), who quoted a personal communication from Archer, Mesodon appressus is never abundant on non-calcareous soils; however, in the upper valleys, this species was more abundant percentage-wise than its 2 closest contenders, M. ruglei and M. sayanus, comprising on the average 8.55% of the fauna (1.94% to 12.82%). Below and including station 7, the popula- tion seldom exceeds 5% of the total, and when it does (11.45% at station 11, for example), the population is nearly always exceeded by M. ruglei or M. sayanus (see below). Most specimens were found burrowing beneath dead leaves or under stones and logs. Mesodon sayanus (Pitssry, 1906) Collecting sites: 1(2), 2(1), 4(3), 5(8), 6(4), 7(17), 8(1), 9(9), 10(15), 11(9), 12(1), 13(15), 14(9) This species develops its largest populations, compared Page 340 with competitors, in the middle to lower slopes, down to around 100 feet. From the upper stations to the lower, there is a steady increase percentage-wise, ranging from 1.63% to 6.20% from stations 1 through 9. Below station 9, except for station 12 (which has been nearly denuded of trees by agriculture), the percentage composition ranges from 7.50% through 23.45%. At stations where the per- centage ran low, the populations of Mesodon ruglet were larger. Mesodon sayanus is distinctly a forest-floor species. All of our specimens were found near the bases of hard- wood trees, along the edges of logs and large boulders where considerable quantities of leaves had accumulated. Mesodon ruglei (SHUTTLEWoRTH, 1852) Collecting sites: 1(5), 2(8), 3(4), 4(3), 5(10), 6(6), 7(53), 8(4), 9(42), 10(1), 11(18), 12(5), 13(10), 14(14) Mesodon ruglei is the dominant polygyrid in the study area, and, indeed, one of the most abundant mollusks present. It seems to have no definite altitudinal preference. Pitspry (1940) reported it to ascend up to 5000 feet in other regions. Only at 3 stations (1 (4.85%), 4 (2.91%), and 10 (1.56%), did its population fall below 5% of the total, averaging 11.83% (5.26% to 19.87%). The species likewise was found in various microhabitats: beneath large and small stones, in dry talus, burrowing in leaves, under decaying logs, and at the base of clumped grasses on the flood plains. Triodopsis tridentata (Say, 1816) Collecting sites: 1(7), 2(5), 3(6), 4(3), 5(7), 6(2), 7(19), 9(9), 10(1), 11(4) This Appalachian species was said by Pirssry (1940) to prefer limestone soils in hilly, shaded terrain and to avoid plains. However, ARCHER (1942) found Triodopsis tridentata abundant in sandstone uplands of low relief with pinewoods cover. These latter findings are essentially similar to ours, with the exception of differences in sylvan conditions. From our findings it is apparent that T.- tridentata produces the largest populations in the uplands (6.79%, 8.77%, and 15.38% at stations 1, 2, and 3, re- spectively), becoming much less abundant in the lower ends of the valleys, except in isolated situations at middle altitudes (station 7: 6.93%), 1.53% to 4.16% of the total population. Below station 11 it is replaced by the following species. Triodopsis fraudulenta (Pitssry, 1894) Collecting sites: 12(3), 13(15), 14(15) Very little is known concerning the habitat requirements and ecology of this species. It is the dominant Triodopsis in the lower valleys (5.45%, 13.39%, and 12.50% at the 3 stations), where we found it primarily on afternoon- THE VELIGER Vol. 12; No. 3 shaded slopes under leaves and decaying wood. KAHN & Kemp (1930) reported the species as more common on lower slopes than in the highlands. Triodopsis denotata (Férussac, 1821) Collecting sites: 7(4), 9(8), 10(1), 13(1) This is is another distinctly lowlands species, as shown by our records. In fact, it was found only on the flood plains beneath water-deposited debris and logs. At the 4 stations listed above, it was never abundant (1.45%, 3.70%, 1.56%, and 0.89%, respectively), and these find- ings coincide with the senior author’s observations at other Kentucky localities. As shown in Table 2, Triodopsis denotata comprised only 0.82% of the total molluscan fauna, only slightly more abundant than Stenotrema an- gellum and Mesodon zaletus. Triodopsis albolabris (Say, 1816) Collecting sites: 1(1), 4(9), 5(2), 6(3), 7(8), 8(2), 9(5), 10(2), 11(3), 12(1) With the exception of station 4, where the population amounted to 8.73% of the total, Triodopsis albolabris is not abundant at any sampled locality in the valley system (0.97% to 3.27%). Pitspry (1940) found the species to be scarce on sandstone substrate in the Catskills. Our specimens were found beneath accumulations of leaves in rock crevices, at the bases of trees, and beneath logs. HAPLOTREMATIDAE Haplotrema concavum (Say, 1821) Collecting sites: 2(1), 4(1), 6(3), 7(20), 8(7), 9(11), 10(1), 11(9), 12(10), 13(7), 14(11) This is a common species of bluffs overlooking streams, especially on the lower slopes where leaf mold and woody debris abound. It is heavily preyed upon by shrews and Peromyscus, and in turn preys upon polygyrids. The pop- ulations were relatively small in upland situations, ranging from 0.97% to 2.63% from station 1 through station 7. From station 8 downward, the populations were much larger, sometimes attaining dominant numbers, such as those at 8 and 12 (11.47% and 18.18%, respectively), averaging 6.19%. Haplotrema accounted for 4.75% of the total fauna. ZONITIDAE The 8 genera in our collections accounted for 38.52% of the total fauna. Two genera, Mesomphix (13.44%) and Ventridens (12.74%), are responsible for most of the population, with Retinella (6.04%), Gastrodonta (3.52%), and Striatura (1.40%) ranking third, fourth, Vol. 12; No. 3 and fifth. The remaining 3 genera produced the following relationships: Paravitrea (0.99%), Zonitoides (9.35%), and Euconulus (0.17%). Similar data are presented for individual species in Table 3. Table 3 Percentage-Composition by Zonitid Species in a Northern Kentucky Faunule % of total Species fauna Euconulus chersinus (Say, 1821) 0.17 Retinella wheatleyi (BLAND, 1883) 1.64 Retinella indentata (Say, 1823) 0.05 Retinella carolinensis (CocKERELL, 1890) 0.88 Retinella cryptomphala (Cxapp, 1915) 3.46 Mesomphix inornatus (Say, 1821) 3.99 Mesomphix perlaevis (Pirssry, 1900) 6.92 Mesomphix vulgatus (H. B. Baker, 1933) 0.29 Mesomphix cupreus (RAFINESQUE, 1831) 1.93 Mesomphix capnodes (BINNEY, 1857) 0.29 Paravitrea species 0.05 Paravitrea multidentata (BINNEY, 1840) 0.11 Paravitrea placentula Prtspry, 1946 0.05 Paravitrea capsella (Goutp, 1851) 0.64 Paravitrea species a 0.05 Paravitrea species b 0.05 Gastrodonta interna (Say, 1822) S52. Ventridens demissus (BINNEY, 1843) 12.74 Zonitoides nitidus (MULLER, 1774) 0.17 Zonitoides arboreus (Say, 1816) 0.17 Striatura ferrea Morse, 1864 1.40 Euconulus chersinus (Say, 1821) Collecting sites: 7(2), 12(1) Euconulus is not, according to our studies, a snail of the dense forests. Our specimens were secured from clumps of grass in clearings. ARCHER (1939) described the species as being characteristic of the grassy slopes of old gullies in Michigan. Retinella wheatleyi (BLAND, 1883) Collecting sites: 4(4), 5(6), 6(2), 7(10), 9(4), 10(1), 11(1) Although widespread in the upland and middle stations, Retinella wheatley: was not found to be the dominant member of its genus. The snail was relatively more abun- dant from station 4 through 7 (1.75% to 3.88% of the total fauna) than from station 9, 10, and 11 (1.04% to 1.56%). The species lives primarily on the lower slopes just above the stream, and on the flood plain, beneath THE VELIGER Page 341 leaves, logs, rocks, and other moisture-conserving struc- tures. Retinella indentata (Say, 1823) Collecting site: 1(1) A single dead shell was collected at this site, and it probably washed into the canyon from above. Retinella carolinensis (CocKERELL, 1890) Collecting sites: 7(1), 8(5), 9(6), 12(3) Pirspry (1946) related that the type locality for this species was the lower slopes of Roan Mountain (Great Smokies), and he further stated that the species was prob- ably found only on the lower slopes of protected valleys. In this we concur. We did not secure specimens until station 7, where the population was meagre (0.36% of the total). The percentages at stations 8, 9, and 12 were 8.19, 4.44, and 5.46, respectively. An additional interesting observation is, when Retinella carolinensis occurs sym- patrically with R. cryptomphala, the former species tends to replace the latter. At stations 8, 9, and 12, the popula- tion percentages for R. cryptomphala were 3.27, 3.70, and 3.63, respectively. Retinella cryptomphala (Capp, 1915) Collecting sites: 1(2), 2(4), 3(5), 4(1), 5(2), 6(6), 7(14), 8(2), 9(9), 10(1), 11(4), 12(2), 13(7) Not only did this species occupy varying habitats — leaf litter, decaying logs, clumps of grass, the undersides of rocks — but it was found at all elevations, and from a percentage comparison there seemed to be no differential regarding preferences, other than the relationship men- tioned above. The densest population, in relation to the total fauna, occurred at station 3. However, this reflects the decreased numbers of other species present rather than an absolute increase in Retinella cryptomphala. Such local variations are common in land snails, and are probably responses to edaphic conditions. Mesomphix inornatus (Say, 1821) Collecting sites: 8(3), 9(14), 10(6), 11(14), 12(3), 13(8), 14(8) Pi_spry’s statement concerning the habitat of this spe- cies, 1. €., “moist, shaded slopes and ravines among leaves and dead wood,” is supported by our findings. Moreover, the absence of the species from the uplands and head-valleys is striking. After its first appearance at station 8, the species was present in dominant to co-dom- inant numbers (4.91% to 14.58%), often sharing its po- sition with the next species. We did not secure specimens from the valley rim or upper slopes; all specimens were found at the lower levels. Page 342 Mesomphix perlaevis (Pirssry, 1900) Collecting sites: 1(4), 2(6), 3(3), 4(3), 5(5), 6(13), 7(27), 8(10), 9(9), 10(1), 11(3), 12(5), 13(10), 14(12) Found under dead leaves and decaying wood in the middle to lower slopes at every station, and ranging from 1.56% to 16.39% of the fauna, this species has the widest ecological distribution of any Mesomphix in the area. As indicated above, in some areas it occupies co-dominant status with M. inornatus. There did not appear to be pref- erence for the small, heavily shaded valleys over the wider, less heavily shaded ones, although the average percentage of the total fauna from station 1 through 7 was 7.06 contrasted with 7.75 for stations 8 through 14. Mesomphix vulgatus (H. B. Baker, 1933) Collecting site: 9(5) Because of the close-set spiral rows of microscopic pa- pillae on the upper and lower surface of the last whorl, these 5 specimens were tentatively identified as this spe- cies. However, as HusricHt (1962b) pointed out, -diag- noses based solely on shell characteristics in this group are always open to question. Nevertheless, the shells are nearly identical with ones from which the soft anatomy was dissected. Mesomphix vulgatus is, with the next two species, a member of third-order valley faunas, seldom being found in the smaller, drier first and second order systems. Wherever we have found the species accompanied by M. perlaevis or M. inornatus, or both, it has always been slightly to greatly outnumbered by them. Mesomphix cupreus (RAFINESQUE, 1831) Collecting sites: 2(5), 9(2), 10(5), 11(2), 12(2), 13(9), 14(8) Regardless of the fair-sized sub-colony at station 2 (living in a pocket of deep humus against a fallen tulip tree), Mesomphix cupreus characteristically is a middle to lowland species, as evidenced by our percentage array from stations 9 through 14: 1.48, 7.81, 2.08, 3.63, 8.03, 6.65, respectively. Pitspry’s (1946) habitat observations coincide essentially with ours: “usually found partially buried in damp humus, under a layer of dead leaves.” Mesomphix capnodes (BinNEyY, 1857) Collecting sites: 13(2), 14(3) Our 5 specimens were removed from deep piles of dead hardwood leaves on the west slope of the valley; both sites were well shaded. Although we did not carry our observations on into the lower Red River System, we have collected the species from several loci since, always in subordinate numbers. Mesomphix capnodes appears to be another species of valleys of at least third-order - magnitude. THE VELIGER Vol. 12; No. 3 All of the Paravitrea specimens listed below were se- cured from similar situations, i. e., from the interstices of moist, deeply placed talus near the point where the slopes leveled out into the floor of the valley. With the exception of P. capsella (8.14%), none of the species was secured in large numbers. The following percentages were ob- tained: P multidentata (0.60% and 1.04%), P. placentula (0.60%), P species a (0.60%) and P species b (1.75%). Although too few specimens were found to allow deriva- tion of ecological generalizations, the records are impor- tant from the standpoint of succession (discussed below). Paravitrea species Collecting site: 4(1) A single specimen, too immature to identify. Paravitrea multidentata (BINNEY, 1840) Collecting sites: 9(1), 11(1) Paravitrea placentula lithodora Pitspry, 1946 Collecting site: 9(1) Heretofore known only from Pine Mountain in Harlan County, this form probably merits specific recognition. Paravitrea capsella (Goutp, 1851) Collecting site: 9(1) The exact relationship of this species to its western counterpart in the Ozarkian-Ouachitan region, Paravitrea significans (BLAND, 1866), is quite hazy and in need of detailed study. Paravitrea new species? a Collecting site: 2(1) Shell small, pale yellowish, sub-shining; spire nearly flat, with very shallow sutures minutely rebordered by transparent shell material; 54 whorls, rather flat-sided, curving gently to the sutures, the last slightly but defi- nitely expanded; umbilicus deep, slightly lunate, nar- row, the central portion about 9 times in diameter, but expanding in the last whorl to about 5 times in diameter; aperture deeper than wide, lunate; lip thin, simple; first whorl smooth, on remaining ones growth striae raised, irregular, becoming nearly regular on last two whorls; spiral, incised sculpture minute above, more or less ob- vious on otherwise smooth base; about one-third the way in from aperture there is a transverse band of 5 very low, contiguous tubercles. Diameter 2.7 mm; height 1.3 mm; umbilical diameter 0.5 mm. Deposited in the Field Museum of Natural History, Chicago; No. FMNH 155477. Vol. 12; No. 3 THE VELIGER Page 343 This form is most closely related to Paravitrea metallica Husricut, 1963 (Husricut, 1963 c), being similar in size, whorl configuration, and in possessing an expanded last whorl. It differs from it in possessing a larger umbili- cus, more regular sculpture, in having its aperture higher than wide, and in having more and differently arranged shell teeth. The teeth are arranged in one or two pairs in P metallica, and the aperture is wider than high in that species. Paravitrea new species? b Collecting site: 9(1) Shell small, very pale tan, glistening; spire barely con- vex, with shallow sutures, not re-bordered; whorls 534, slowly expanding; upper periphery of body whorl slightly angular, base well-rounded; umbilicus deep, well-like, displaying all whorls, the central hole about 84 times in diameter, expanding to about 4 times in the last whorl; aperture only slightly wider than high, simple, toothless ; nucleus of 14 whorls, smooth; sculpture of nearly regular growth striae and radial grooves, crowded. Diameter 2.5 mm; height 0.9mm; umbilical diameter 0.4 mm, This species appears to be most nearly related to Para- vitrea tantilla Husricut, 1963 (Husricut, 1963c) by way of the shallow sutures, slowly increasing whorls, and apertural and lip characters, but differs from that species in possessing more regular sculpture, a larger umbilicus, much smaller size (this form has nearly the same number of whorls as P tantilla but is 1.2mm smaller), and by lacking shell teeth. Gastrodonta interna (Say, 1822) Collecting sites: 1(11), 2(1), 4(2), 5(13), 6(2), 7(4), 9(10), 10(1), 12(1), 13(5) Practically nothing has been published concerning the ecology of this, one of the most distinctive genera of North American snails. It lives on shaded slopes beneath dead leaves, although it seems to avoid Rhododendron and mountain laurel. At station 1 we found it abundantly beneath white pine needles. ARCHER (1942) also found the species associated with pine woods. There may be a slight preference for smaller valleys over the larger ones. The average composition-percentage in the upper valleys (stations 1 through 7) was 4.35% (1.45% to 10.67%), whereas in the lower ones (stations 9, 10, 12, 13) it was 3.46% (1.56% to 6.02%). However, sampling error could account for this small difference. Ventridens demissus (BINNEY, 1843) Collecting sites: 1(28), 3(4), 4(30), 5(56), 6(33), 7(31), 8(24), 9(5), 10(4), 12(1) Ventridens was absolutely the single most-abundant species present in the study area from station 8 upward, and is mainly responsible for placing the Zonitidae as the second most abundant family. By station, the relative percentages were (station numbers in parentheses) : (DR 27e18i (3). 10:2551(4:)) 2951255 (5))) 35:89), (6) 28:94; (7) 11.31, (8) 39.34, (9) 3.01, (10) 6.25, and (12) 1.81. A sharp decrease in abundance was noted from station 9 downward, a trend we have also noted elsewhere. Our specimens were collected mostly from the upper and middle slopes, beneath dead leaves and logs. Such large populations are common in the genus. Mayer (1965), for example, reported one specimen of V. suppressus (Say, 1829) per square inch of log surface in Pennsylvania. Zomitoides nitidus (Mu.ErR, 1774) Collecting sites: 1(1), 2(2) These specimens, representing 0.97% and 3.50% of the total populations at the 2 stations respectively, were found beneath dead leaves just above the stream margin. Pirs- BRY (1946) indicated that the species was generally found near water in lowland situations, never in upland woods, and ARCHER’s (1939) observations were essentially the same in Michigan. Zonitoides arboreus (Say, 1816) Collecting sites: 4(1), 7(2) The specimen from station 4 was found under a dead log on the flood plain, and those from station 7 under slabs of sandstone about half-way up the slope. Although Zoni- toides enjoys a much wider ecological range, up to at least 10000 feet in the west, and down to sea level in the south, it is never found far from moist situations. Usually, the species is found in or around decaying wood. At these 2 stations, the small numbers represented only 0.97% and 1.14% of the population, but in other locali- ties we have it to constitute as much as 20%. The species has a very erratic distribution within a given area. Striatura ferrea Morse, 1864 Collecting sites: 1(8), 3(4), 4(2), 5(2), 8(2), 11(3), 13(3) Following the same sequence as above, the composition percentages at each station were: 7.76, 10.25, 1.94, 1.28, 3.27, 6.25, and 2.67. There does not appear to be definite correlation between valley magnitude and the presence of this small mollusk. Since the specimens all came from the valley floors, under wet to damp leaves and decaying wood, conditions near to or at dew point perhaps limit the species’ distribution. Page 344 THE VELIGER Vol. 12; No. 3 LIMACIDAE Only a single species in this family was collected, repre- senting only 0.70% of the total collection. Deroceras reticulatum (MU.uer, 1774) Collecting sites: 1(1), 4(10), 8(1) All specimens of this widespread exotic species (GETZ, 1959) were found near the stream beneath decaying wood ; the 10 at station 4 were collected from an old U.S. For- estry marker. The percentages at the 3 stations were: 0.97, 9.70, and 1.63. ENDODONTIDAE Sixty-two specimens, or 3.61% of the total, were col- lected. The genus Discus was most abundant, 2.75%, with Anguispira (0.58%), Helicodiscus (0.17%), and Punctum (0.11%) in less quantities. Since each genus, except Discus, was represented by single species, the per- centages were the same at the specific level. In Discus, D. patulus represented 2.70% of the population, and D. bry- anti only 0.05%. Anguispira alternata (Say, 1816) Collecting sites: 11(6), 12(2), 13(1), 14(1) Our specimens are very definitely the lowland form termed angulata by Pitspry (1948). They were collected on the south slopes just above the stream, from beneath decaying logs. This propensity for wood was also noted by MacMiiian (1940). Percentage-wise, the species was most abundant at station 11 (6.25%), and decreased in abundance below that point, 3.63%, 0.89%, and 0.83%, respectively. This possibly reflects the more open nature of the last 3 stations. Discus patulus (DeEsHAyYEs, 1830) Collecting sites: 1(41), 2(1), 4(1), 5(3), 8(1), 9(11) Another species with distinct decaying-woods affinity (Husricut, 1963; Pirspry, 1948). There was a distinct preference for the heavily shaded portions of the upper valleys, especially the lower, moist slopes thereof. The percentages by stations were: 22.33, 1.25, 0.97, 1.92, 1.63, and 8.14, respectively. The presence of the relatively large population at station 9 probably was in response to the dense shade and abundance of moist, decaying wood. Discus bryanti (Harper, 1881) Collecting site: 9(1) Although this is characteristically a woodland species, our siftings of forest floor debris did not disclose its pres- ence at any of the upper stations. At the 2 lower stations, where the population percentages ran 1.63 and 1.20, the specimens were associated with decaying wood. From past observations, the senior author feels that this and other Helicodiscus and related species tend to avoid Rhodo- dendron. Consequently, since H. parallelus has been found at 5000 feet elevation in Tennessee (Pmssry, 1948), the apparent restriction to the lower valleys may be correlated with the marked decrease in Rhododendron at those sta- tions. Bascu et al. (1961), however, found the species more common on flood plains. Punctum minutissimum (Lr, 1841) Collecting site: 7(2) Our specimens were found beneath a deep pile of de- caying hardwood leaves. According to Morse (in Pits- BRY, 1948), this minute species prefers the “rotten bark of beech trees,” a common tree in the study area, although somewhat scattered. Our scanty records, of course, did not allow us to corroborate Morse’s statement. PHILOMYCIDAE The two genera and 4 species of these rather typical eastern slugs made up 2.16% of the total collection, with Pallifera accounting for 1.40%, and Philomycus for 0.76%. By species, the following data were obtained: Philomycus carolinianus 0.17%, P. flexuolaris 0.58%, Pallifera dorsalis 1.18%, and Pallifera fosteri 0.23%. Philomycus carolinianus (Bosc, 1802) Collecting sites: 1(1), 10(2) Only collected from the space between the bark and trunk of decaying hardwood logs on the flood plains and lower slopes, our records corroborate BRANSON’s (1962) conclusion that this is a flood plains species. It probably occurs throughout the system. At the 2 localities, Philo- mycus carolinianus accounted for 0.97% and 3.12% of the fauna. INcram (1949) found this slug in New York beech-hemlock associations, but observed that it avoided hemlock logs. Philomycus flexuolaris (RAFINESQUE, 1820) Collecting sites: 4(4), 8(2), 9(3), 12(1) Long considered a subspecies of Philomycus carolini- anus (Pitspry, 1948, and others), Husricut (1951) demonstrated the distinctness of this large brownish slug. Ecologically it is also distinct, since the preferred habitat is beneath stones and in rock fissures in the upland slopes. All of our specimens were found beneath logs, lying on sand, stone, or under rocks. In the station order shown above, the percentages ran 3.88, 3.27, 2.22, and 1.81. Vol. 12; No. 3 THE VELIGER Page 345 Pallifera dorsalis (BINNEY, 1842) Collecting sites: 3(1), 6(3), 7(2), 10(1), 12(6), 13(4), 14(3) Although widespread in the valley system, this form had a rather decided preference for the lower stations. It was found on the lower slopes and on the flood plains beneath decaying leaves, along the edges of logs, and beneath stones. DimELow (1962) found Pallifera dorsalis common in Nova Scotian deciduous leaf litter. The per- centages were: 2.56, 2.63, 1,14, 1.56, 10.90, 3.57, and 2.50. Pallifera fosteri F.C. Baker, 1939 Collecting sites: 3(1), 7(2), 10(1) The external and internal anatomy of these specimens was in essential agreement with the findings of Grimm (1961) and Wess (1952). From past observations (BRAN- SON, 1962), it is apparent that this form is strictly a species of very moist flood plains. All of our specimens were removed from decaying logs in mud flats. PUPILLIDAE Only 2 specimens of one species were collected. Gastro- copta is not in general a well-adapted mountain genus, although certain sections of the genus are. The species dis- cussed below, for example, seems to be absent from the higher parts of the Allegheny Mountains (Pitspry, 1948), and Cuan & Kemp (1930) reported the species as only locally abundant in an Indiana locality. At lower eleva- tions, G. contracta prefers mesic situations under dead woods and leaf mold (Bascu e¢ al., 1961). In our study, Gastrocopta comprised only 0.11% of the total fauna. Gastrocopta contracta (Say, 1822) Collecting sites: 2(1), 9(1) The percentage composition at station 2 was 1.75, at station 9 it was 0.74. CIONELLIDAE This family is represented in North America by a single widespread species, Cionella lubrica (MULLER). In this study it represented 1.05% of the fauna, all of our speci- mens being secured from the moist, heavily-shaded spots at each station, beneath thick layers of damp to wet decaying leaves. Cionella lubrica morseana DoHERTY, 1878 Collecting sites: 1(1), 2(4), 7(2), 8(1), 9(5), 10(1), 12(1) _ The following percentages were calculated for the above Stations O:9/ee/Oly Ll4 63.0 370 leo On lol. AQUATIC SPECIES It has often been observed that slightly alkaline waters are more productive of mollusks than soft ones. However, very few reports present chemical characteristics of the water from which gastropods were collected. SHoup (1943), studying various streams in the Obey River Drainage, Tennessee, found that streams flowing over sandstones of the Lee Formation were in general poor in bicarbonates, some of them as low as 2 to 6 parts per million. According to his findings, streams with bicarbon- ates below 20 ppm possessed depauperate mollusk faunas. In the discussion which follows, it will be noted that mollusks were entirely lacking at all of the upland stream stations, not appearing before station 11. A glance at Table 1 will reveal very low bicarbonate in the crystal clear water until station 11, where the stream leaves the Lee Formation, and where the bicarbonate reaches a level above 40 ppm. There are, of course, other considerations. Many aquatic snails are invariably associated with rooted vegetation, such as Campeloma (A.uson, 1942; Bovpyerc, 1952), Lioplax, and certain species of Physa (BickeL, 1965). Since the water in our study area is subject to much fluctuation in depth, and probably also because of low carbonate content, rooted plants are very scarce to ab- sent. In other words, the type of marginal habitat re- quired by amnicolid and physid snails is lacking in the headwater situations, but becomes progressively more available downstream. In our study 4 families of aquatic snails were encoun- tered, although the first form discussed is actually amphi- bious. LYMNAEIDAE Lymnaea humilis Say, 1822 (= L. dalli F C. Baker), the single species (7 specimens) collected by us at station 11, comprised 0.41% of the total fauna, and 7.29% of the fauna at the collecting site. As indicated above, this is an amphibious form; our specimens were found crawling on vertical sandstone some 5 feet above the water. This is apparently common, as Baker (1911) indicated that the species was “generally out of water on sticks and stones or mud flats.” PHYSIDAE Only a single species in this nearly ubiquitous family was secured, representing 0.76% of the total collection. Page 346 THE VELIGER Vol. 12; No. 3 Physa integra HALDEMAN, 1843 Collecting sites: 13(5), 14(8) The local percentages were 4.46 and 6.67, respectively. As already mentioned, BickeL (1965) has demonstrated this species’ dependency upon rooted vegetation. Since the upper stations had little vegetation, its absence there could be expected. Our specimens were secured in back- water situations on decaying leaves and Potamogeton. Outside the study area, downstream in Red River, the species becomes abundant on Dianthera, where it is associated also with Campeloma. ANCYLIDAE The ecology of this very interesting family, which ac- counted for 0.52% of the mollusks found by us, remains sketchy. Two species, in separate genera, were secured. Laevapex fuscus (C. B. Apams, 1840) Collecting site: 14(1) Characteristically a species of lakes and slow-flowing rivers, our single specimen (0.83% of the local fauna) was removed from a dead leaf in a side-pool. Rhodachmea elatior (ANTHONY, 1855) Collecting site: 14(8) These specimens, comprising 6.67% of the local fauna and 0.40% of the total collection, are the first collected in Kentucky since ANTHONY described the species from Green River. This is a rather important discovery, since Bascu (1963) indicated that the species was known def- initely only from the Cahaba River in Alabama. Our spe- cimens were found on stones in a swift riffle. AMNICOLIDAE Somatogyrus subglobosus (Say, 1825) The single specimen of Somatogyrus subglobosus (Say, 1825) found at station 14 constituted 0.05% of the total collection and 0.83% of the local fauna. It was associated with the Rhodachmea. DISCUSSION anp CONCLUSIONS Longitudinal succession in stream organisms, from head- waters downward, is a well-known principle (Opum, 1959), one which KuEHNE (1962) has correlated with Horton’s (1945) drainage classification as modified by STRAHLER (1954, 1957). Horton’s system is based on stream branching, and intermittent or permanent head- water streams are classified as Order 1. The union of 2 equal-ranked streams forms one of the next highest order, but the rank of the stream is not increased by the entrance of one of lower order than itself, KuEHNE’s (op. cit.) work showed a progressive increase in the average number of fish species present with an increase in stream order, and he suggested this relationship reflected adaptations to local conditions. With these studies in mind, we decided to sample mol- lusk populations to test the hypothesis that valleys them- selves could be ranked by order, which in turn would be reflected in the terrestrial fauna. The correlation with stream order is obvious in the aquatic forms (see above). In terrestrial species there also seems to be a definite correlation between valley order and number of species present (Figure 3). The average number of species at the Station 123 4 5 6 7 8 9 10 11 12 13 14 Number of Species oO Figure 3 Graph showing Species Abundance per Station. Average for upper 7 stations: 17.3; average for lower 7 stations: 20.6. upper 7 stations was 17.3, contrasted with 20.6 at the lower 7. Figure 4 shows the distribution of all species collected, thereby demonstrating longitudinal succession. None of the species was restricted to order 1 or order 2 valleys, but 4 species, Mesodon thyroidus, Mesomphix inornatus, Mesomphix cupreus, and Retinella carolin- ensis, were found only in order 3 and 4 valleys. Several of the other species, such as some Paravitrea, may also be restricted to the larger systems. Another aspect of longitudinal succession observed was that of relative abundance. Roughly, 4 main patterns were observed (Figure 5): most abundant in order 1 and 2 valleys with decreasing abundance downgrade (Ventri- Vol. 12; No. 3 THE VELIGER Page 347 n OO OO|~s ° i=] a — Oo — — Stenotrema evardsi il 2 © © Stenotrema stenotrema ©) © OQ © OO] & OO OO} = Stenotrema angellum Stenotrema barbatum Stenotrema leat OOOO} O OO OO} OO OQ OO!|© O Mesodon thyroidus Mesodon zaletus Mesodon appressus Mesodon sayanus OOO OOlIO OOO] COOO|OO © |©CO OClO©O OCjOO© OO)|& Mesodon ruglet O|OOO O|OO0O ClOOQ CO\OO© © O|O O;|OO0O Triodopsis tridentata Triodopsis fraudulenta Triodopsis denotata Triodopsis albolabris Haplotrema O ©m|COCOO||© O OO O OO OO O|\OO O© |OO© O Euconulus Retinella wheatleyi CO. O © Retinella indentata Retinella carolinensis Retinella cryptomphala © |©OOO C|OO© @) e) O O O © Mesomphix inornatus Mesomphix perlaevis CoO O OO © ©O Mesomphix vulgatus Mesomphix cupreus Mesomphix capnodes © OCG COOLO OClOOO© OO/|OO QO OO|© OQ CO \W© © OO|O© OO OO|© COO O© O Paravitrea placentula Paravitrea multidentata Paravitrea capsella Paravitrea lafuzi Paravitrea sceada O Gastrodonta Ventridens Zonitoides nitidus Zonitoides arboreus Striatura OO O}] © O OO OO OO OO O OO OO O|O Derocerus Anguispira Discus patulus Discus bryanti Punctum O Philomycus carolinianus Philomycus flexuolaris O @e@® Pallifera dorsalis Pallifera fosteri Gastrocopta Cionella Lymnaea O Physa @ Laevapex Rhodachmea Somatogyrus © ClOOOOl O O O CO OO OO O O;O OO O O OC! COOO O O O OOOO Figure 4 Graph showing Occurrence.of Mollusks at Collecting Stations. Station 3G fy I 2 Ventridens 25 Number of Specimens Mesodon evardst Mesodon Sayanus Figure 5 Graph showing Distribution by Numbers in Four Molluscan Species. dens), most abundant in order 2 and order 3 valleys (Ste- notrema evardsi), most abundant in order 4 valleys (Me- sodon sayanus), and more or less abundant throughout the system (Mesodon appressus). Other species could have been selected, but these are representative. Some of the sporadic variation may be the result of local differ- ences in edaphic conditions (BurcH, 1955) and, indirect- ly, the occurrence of favorable plant associations (BURCH, 19577) A final, and perhaps more important, observation is illustrated by Figures 6 and 7. It appears that when 2 snail species with similar habitat requirements occur to- gether sympathically one or the other’s population is held in abeyance, probably according to which species is favored by the particular environment. In the case of Mesodon appressus, which we have already indicated _ produces its largest populations in the uplands, versus M. sayanus (Figure 6), it can be seen that M. sayanus is THE VELIGER 7 8 9 TO Re oe Ue} wi Vol. 12; No. 3 Station 1 2 3 4 5 6 7 8 g 10 11 12 13 14 30 ew ° Te 3 % 20 Mesodon o — sayanus 8 3 | Hi § Mesodon 5 10 — appressus a 5 Figure 6 Graph showing Station Percentages for Mesodon appressus and Mesodon sayanus. held to relatively small populations in the uplands, where- as there is a tendency to reversal in order 3 and order 4 valleys. In Mesomphix perlaevis versus M. inornatus the contrast is even more striking (Figure 7). These compe- titive relationships need intensive study. Comparisons of disturbed versus undisturbed areas showed no positive correlations. 8 9 10 11 12 13 14 20 ~ ao Mesomphix inornatus Mesomphix perlaevis o Percen Station Collection C) Figure 7 Graph showing Station Percentages for Mesomphix perlaevis and Mesomphix inornatus. ——————————————————— a i ea ee Vol. 12; No. 3 THE VELIGER Page 349 SUMMARY 1. Fourteen randomly selected stations, located in Wolfe and Powell Counties, Northern Kentucky, were sys- tematically searched for terrestrial and aquatic mol- lusks, the habitat conditions at each station were detailed, and information on plant associations and water chemistry secured. 2. Twelve families, 26 genera, and 52 species, two ap- parently new, were collected. 3. The family Polygyridae is the dominant taxon present in the study area, 47.26% of the total fauna. It is followed by the Zonitidae, 38.52%. The remaining 14.22% of the fauna is unequally divided between the other 10 families. 4. The percentage-composition of the total fauna was calculated for each genus, showing Mesodon (23.67%), Stenotrema (15.03%), Mesomphix (13.44%), and Ventridens (12.74%) to be the dominant ones. 5. The number of each species collected per station is presented; percentages were calculated as regards the total fauna and the faunas at each station. Mesodon ruglei (10.74%) and Ventridens demissus (12.74%) are the two dominant species in this region. 6. Observations on habitat and ecology are presented in discussions of individual species. 7. Analysis of ecological distribution demonstrates a positive correlation between the number of species present and valley magnitude. No species were restric- ted to valleys of first or second order, but several were found only in order 3 or order 4 valleys. 8. Correlated with low concentrations of calcium car- bonate in order 1, 2, and 3 streams, aquatic mollusks are restricted to order 4 streams in the study area. 9. Relative abundance observations disclosed 4 main patterns: (a) greatest abundance in order 1 and 2 valleys, decreasing in abundance downgrade; (b) great- est abundance in order 2 and 3 valleys, decreasing up- and downgrade; (c) greatest abundance in order 4 valleys, decrease upgrade; and (d) abundant through- out the system. Examples of each type of distribution are included. 10. Sympatric species with similar ecological require- ments, according to local environmental conditions, mutually affect populations, either by suppressing an associated species or being suppressed by it. LITERATURE CITED Auuson, L. N. 1942. Trapping snails of the genus Campeloma. 95: 131 - 132 Science AnTHoNny, J. G. 1855. Descriptions of new species of Ancylus and Anculosa, from the western states of North America. Ann. Lyc. Nat. Hist. New York 6: 158 - 160 ARCHER, ALLAN Frost 1939. The ecology of the Mollusca of the Edwin S. George Reserve, Livingston County, Michigan. Occ. Pap. Mus. Zool. Univ. Michigan 398; 1 - 24 1942. Pine woods as adequate habitat types for land Mollusca. The Nautilus 55 (3): 94-97 1948. Land snails of the genus Stenotrema in the Alabama region. Geol. Surv. Alabama Mus. Pap. 28: 1 - 85 BAKER, FRANK COLLINS 1911. |The Lymnaeidae of North and Middle America. Chicago Acad. Sci. Spec. Publ. 13: i- xvit1 - 539; plts. 1-58 Bascu, Pau. FE 1963. A review of the Recent freshwater limpet snails of North America (Mollusca : Pulmonata). Bull. Mus. Comp. Zool. Harvard 129: 400 - 461 Bascu, Paut F, PHiturp BaIneR & JERRY WILHM 1961. Some ecological characteristics of the molluscan fauna of a typical grassland situation in east-central Kansas. Am. Midl. Nat. 66: 178 - 199 BickEL, Davip 1965. The role of aquatic plants and submerged structures in the ecology of a freshwater pulmonate snail, Physa integra Ha tp. Sterkiana 23: 19 - 24 1966. Stranded Campeloma. The Nautilus 79: 106 - 107 1967. Preliminary checklist of Recent and Pleistocene Mol- lusca of Kentucky. Sterkiana 28: 7 - 20 Bovpyerc, RicHarp V. 952% Ecological aspects of the dispersal of the snail Campe- loma decisum. Ecology 33: 169 - 176 BRANSON, BRANLEY ALLAN 1962. The slugs (Gastropoda : Pulmonata) of Oklahoma and Kansas with new records. Trans. Kansas Acad. Sci. 65: 110-119 BRANSON, BRANLEY ALLAN & DoNALD LEE BaTcH 1968. Ecological study on valley-forest spiders from Northern Kentucky. Proc. Biol. Soc. Wash. 81: 197 - 208 1969. Valley centipedes (Chilopoda : Symphyla) from North- erm Kentucky. Trans. Kentucky Acad. Sci. 28: 77 - 90 in press Spiders (Arachnida : Araneida) from Northern Ken- tucky, with notes on phalangids and some other localities. Trans. Kentucky Acad. Sci. Burcu, JoHN BayArp 1955. Some ecological factors of the soil affecting the distribu- tion and abundance of land snails in Eastern Virginia. The Nautilus 69 (2) : 62 - 69; 2 figs.; 1 table [1956-.] 1957. Distribution of land snails in plant associations in Eastern Virginia. The Nautilus 70 (2): 60-64; 2 tables; (3): 102-105; 1 fig. Caun, Arvin Ropert & Jack T. Kemp 1930. The terrestrial mollusks of Turkey Run State Park, In- diana. Trans. Illinois State Acad. Sci. 22: 250 - 262 CLENCH, WILLIAM JAMES 1962a. A catalogue of the Viviparidae of North America with notes on the distribution of Viviparus georgianus LEA. Occ. Pap. Mollusca, Mus. Comp. Zool. Harvard 2: 261 - 287 1926b. New records for the genus Lioplax. Occ.Pap. Mol- lusca, Mus. Comp. Zool. Harvard 2: 288 Page 350 THE VELIGER Vol. 12; No. 3 1926. Some notes and a list of shells of Rio, Kentucky. The Nautilus 40 (1): 7-12; (2): 65-67 CLENcH, WILLIAM JAMES & RuTH Drxon TuRNER 1955. The North American genus Lioplax in the family Vivi- paridae. Occ. Pap. Mollusca, Mus. Comp. Zool. Harvard 2: 1-20 Conkuin, James ELWIN 1957. ‘The larger land snails of Sleepy Hollow, Kentucky. The Nautilus 71 (1): 10-11 DimeELow, E. J. 1962. On the biology of some mollusks from a Nova Scotian deciduous wood. The Nautilus 76: 49 - 51 Getz, LowE tu L. 1959. Notes on the ecology of slugs: Arion circumscriptus, Deroceras reticulatum and D. laeve. Am. Midl. Nat. 61: 485 - 498 GoopricH, CALVIN 1921. Three new species of Pleuroceridae. Occ. Pap. Mus. Zool. Univ. Michigan 91: 1-5 1929. The pleurocerid fauna of the Ohio. The Nautilus 43(1):1-17 1934a. Studies of the gastropod family Pleuroceridae. I Occ. Pap. Mus. Zool. Univ. Michigan 286: 1 - 17 1934b. Studies of the gastropod family Pleuroceridae. ITI Occ. Pap. Mus. Zool. Univ. Michigan 295: 1-6 1934c. Studies of the gastropod family Pleuroceridae. III Occ. PapersMus. Zool. Univ. Michigan 300: 1 - 11 1937. Studies of the gastropod family Pleuroceridae. VI Occ. Pap. Mus. Zool. Univ. Michigan 347; 1 - 12 1938. Studies of the gastropod family Pleuroceridae. VII Occ. Pap. Mus. Zool. Univ. Michigan 376: 1 - 12 1940. The Pleuroceridae of the Ohio River drainage system. Occ. Pap. Mus. Zool. Univ. Michigan 417: 1 - 21 1941. Studies of the gastropod family Pleuroceridae. VIII Occ. Pap. Mus. Zool. Univ. Michigan 447: 1 - 13 Grimm, FE Wayne 1961. Pallifera fosteri, with P. megaphallica, new. The Nautilus 74 (3): 102-105; 2 text figs. Horton, Rosert E, 1945. _Erosional development of streams and their drainage basins; hydrophysical approach to quantitative morphology. Bull. Geogr. Soc. Amer. 56: 275 - 370 Hupricut, LESLIE 1950. Mesodon andrewsae normalis (Pits.) in Kentucky. The Nautilus 63 (3): 106 1951. The Limacidae and Philomycidae of Pittsylvania Coun- ty, Virginia. The Nautilus 65 (1): 20-21 1958a. New species of land snails from the Eastern United States. Trans. Kentucky Acad. Sci. 19: 70 - 76 1958b. Quickella vermeta and Succinea indiana. The Nautilus 72 (2): 60-61 1958c. New species of land snails from the Eastern United States. Trans. Kentucky Acad. Sci. 19: 70 - 76 1960. The cave snail, Carychium stygium CAL. Kentucky Acad. Sci. 21: 35 - 38 Trans. 1962a. New species of Helicodiscus from the Eastern United States. The Nautilus 75 (3): 102-107; plts. 7-9; 2 text figs. - 1962b. Mesomphix vulgatus and its allies. The Nautilus 76 (1): 1-3 1963a. Carychium exile and Carychium exiguum. The Nautilus 76: 108 1963b. New species of Hydrobiidae. Nautilus 76: 138 - 140 1963c. Four new species of Paravitrea. The Nautilus 76: 140 - 142 1964a. The bidentate species of Ventridens (Stylommatophora: Zonitidae) . Malacologia 1: 417 - 426 1964b. Land snails from the caves of Kentucky, Tennessee, and Alabama. Bull. Nat. Speleol. Soc. 26: 33 - 34 INGRAM, WILLIAM Marcus 1949. Natural history observations on Philomycus carolinianus (Bosc). The Nautilus 62 (3): 86-90 Kaptan, MicHatEL F « W. L. MIncKLEY 1960. Land snails from the Doe Creek area, Meade County, Kentucky. The Nautilus 74 (2): 62-65 KuEHNE, RoseErt A. 1962. A classification of streams, illustrated by fish distribu- tion in an eastern Kentucky creek. Ecology 43: 608 - 614 Lamar, WILLIAM L. 1949. Determination of color of turbid waters. Anal. Chem. 21: 276 MacMiLian, Gorpon KuTcHKA 1940. A monographic study of the snails of the genera Angui- spira and Discus of North America, exclusive of Mexico. Ann. Carnegie Mus. 27: 371 - 427 Moyer, W. W. ? 1965. Brief census of log-associated snails in Berks county, Pennsylvania. The Nautilus 78: 107 - 108 Opum, EucEene P. 1959. Fundamentals of Ecology. Philadelphia, 546 pp. Or.AND, HERBERT P. (ed.) 1965. Standard methods for the examination of water and wastewater, including bottom sediments and sludges. Am. Public Health Assoc., Inc., New York, 769 pp. Pitspry. Henry AUGUSTUS 1939. Land Mollusca of North America, North of Mexico. Acad. Nat. Sci. Philadelphia Monogr. 3, 1 (2): 574- 994 1946. Land Mollusca of North America, North of Mexico. Acad. Nat. Sci. Philadelphia Monogr. 3, 2 (1): 1-520 1948. Land Mollusca of North America (north of Mexico). Acad. Nat. Sci. Philadelphia Monogr. 3, 2 (2): i-xlvii + 521-1113; figs. 282 - 585 (19 March 1948) Pricr, SADIE F W. B. Saunders Co., 1900. Mollusca of southern Kentucky. The Nautilus 14 (7): 75-79 RosEWATER, JOSEPH 1959. + Mollusks of the Salt River, Kentucky. The Nautilus 73 (3): 57-63 SHoup, CHARLES SAMUEL 1943. Distribution of fresh-water gastropods in relation to total alkalinity of streams. The Nautilus 56 (4) : 130 - 134 STRAHLER, A. N. 1957. Quantitative geomorphology of erosional landscapes. C. R. 19 Intern. Geol. Congr. 13: 341 - 354 Wess, GLENN R. 1952. Pulmonata, Philomycidae: anatomical data on the slugs Pallifera dorsalis, P. fosteri, and a new subspecies. Gastro- podia 1: 6-7 Vol. 12; No. 3 THE VELIGER Page 351 A New Species of Muricopsis from West Mexico BY GEORGE E. RADWIN AND ANTHONY D’ATTILIO San Diego Natural History Museum, San Diego, California 92112 (Plate 52; 4 Text figures) IN THE COURSE OF our continuing study of the Muricidae of the Panamic province of the eastern Pacific we have frequently encountered an apparently undescribed species of Muricopsis from Jalisco state, West Mexico. Almost two years ago the junior author was first shown specimens of this species by Mrs. Ruth Purdy of San Diego, California. Since then, many specimens have been generously made available to us for examination. The number of specimens in private and museum collections is surprisingly large and is indicative that the species is at least moderately com- mon at certain points in the region between Banderas Bay (Puerto Vallarta) and Manzanillo. ABBREVIATIONS USED SDNHS - San Diego Natural History Society LACM - Los Angeles County Museum of Natural History AMNH - American Museum of Natural History Muricopsis Bucquoy & DAUTZENBERG, 1882 Muricidea Morcu, 1852, p. 95, non Swainson, 1840; type species: Murex magellanicus GMELIN, 1791 (=M. geversianus Patuas, 1774) by OD Muricopsis Bucguoy & DAUTZENBERG, in Buc- guoy, DAUTZENBERG & Do.tiFus, 1882, p. 19; type species: Murex blainvillet PAYRAUDEAU, 1862, by OD Remarks: The genus Muricopsis was originally erected for mollusks with small to moderate-sized, spinose or tu- berculate shells, znd with strong denticulation on the inner surface of the apertural lip. Color and degree of sculp- ture vary even within a single species as is noted by Bucqguoy & DAUTZENBERG. The following nominal species from the eastern Pacific are apparently referable to Muricopsis. 1. Murex armatus A. Apams, 1854, p. 71, Gulf of Cali- fornia, Mus. Cuming, (= Muricidea squamulata Car- PENTER, 1865), holotype, BM(NH) no. 1954-4.15.10-12 (see Keen, 1958, fig. 367). 2. Muricopsis zeteki HERTLEIN & STRONG, 1951, p. 85, Panama City, Panama, (== Murex aculeatus Woop, 1828, non Lamarck, 1822) (= Murex dubius Sowersy, 1841, non Dittwyn, i817), holotype (of M. aculeatus): ?>BM (NH), see Dance, 1966, p. 305. 3. Murex pauxillus A. ApaMs, 1854, p. 71, Gulf of Cali- fornia, Mus. Cuming, holotype: BM(NH). 4. Muricopsis jaliscoensis, new species, described below, from Jalisco, West Mexico. The genus Muricopsis has an apparently long and wide- spread fossil distribution. According to WENz (1941), fossil species are known from most world areas; the ear- liest, reported from the Paleocene of Europe. These in- clude: Europe (M. multistriatus DESHAvES), Indo-Paci- fic, North America (M. spinulosa Hettrrin, M. aldrichi CossMANN) and Australia (M. alveolatus TATE). Muricops’s blainvillei (PAYRAUDEAU, 1826) (Plate 52, Figure 3) Murex blainvillii PayRAUDEAU, 1826, p. 149; plt. 7, figs. 17, 18; L’fle de Corse (Corsica). Murex cristatus Broccut; Risso, 1826, vol. 4, p. 191. Cancellaria blainvillt PayRAUDEAU; BLAINVILLE, 1826, p. 139; plt. 5, fig. 4. Page 352 THE VELIGER Vol. 12; No. 3 Figure 1 Muricopsis blainville: (PAYRAUDEAU, 1826) one lateral and one central tooth from the radula (SDNHS no. 51308) Murex pliciferus Brvona-BERNARDI, 1832, p. 22; plt. 3, fig. 10. Murex (Muricidea) blainvillit, PayrAUDEAU; H. & A. Apams, vol. 1, p. 75. Murex (Ocinebra) blainvillii PayrAuDEAU; MonrTE- ROSATO, 1878, p. 40. Murex (Muricopsis) blainvillei PAyRAUDEAU; Buc- Quoy & DAUTZENBERG, 1882, vol. 1, p. 19; Roussillon, France. Distribution: Mediterranean Sea, Atlantic coast of Por- tugal, Spain and North Africa, as well as the Island of Madeira. Also reported, under the name of Murex crista- tus Broccut, 1814 from the Pliocene of Italy. Description of the radula: Each transverse radular row has a single rachidian tooth, flanked on each side by a simple, sickle-shaped lateral tooth (Text figure 1). The base of the rachidian tooth is roughly rectangular with very prominent, downward pointing projections on each end of the rectangle, and 5 sharp cusps. The lateral cusps are quite long and sharp, the intermediate cusps are as sharp, about % as long, and are positioned closer to the lateral cusps than to the central cusp. The central cusp is the longest and strongest of the 5, with a prominent, blade-like highlight along its leading edge. It is borne on a cowl-like structure and projects far in advance of the remainder of the tooth. It is not as down-hooked as is the case in Muzicopsis jaliscoensis and in some other species of Muricopsis. As a result of this great forward extension of the central cusp, it is virtually impossible, under high magnification, to bring it into focus simulta- neously with the remainder of the cusps. Remarks: The type locality of Muricopsis blainvillei is Corsica in the northwestern Mediterranean. For many years, another name has persistently competed with M. blainvillet for primary recognition. Murex cristatus was first described by Broccut (1814) for a fossil species from Explanation of Plate 52 Figure 1: Muricopsis zeteki HERTLEIN & STRONG, 1951, SDNHS no. 50821, Bahia Coastocomate, Jalisco, Mexico; length 21.2 mm; width 13mm Figure 2: Muricopsis armatus (A. Apams, 1854), SDNHS no. 22740, La Paz, Baja California del Sur, Mexico; length 32 mm; width 18 mm : - Figure 3: Muricopsis blainvillei (PayRAUDEAU, 1826), SDNHS no. 51308, Livorno, Mare Tirreno, Italy; length 24 mm; width 12mm Figure 4: Muricopsis jaliscoensis RADWIN & D’ATTILIO, spec. nov. holotype, SDNHS no. 51251, Bahia Coastocomate, Jalisco, Mexico; length 26.5 mm; width 13.8 mm Figure 5: Muricopsis jaliscoensis RADwIN & D’ATTILIO, spec. nov. paratype, SDNHS no. 51250, Bahia Coastocomate, Jalisco, Mexico; length 23.3 mm; width 13mm Figure 6: Muricopsis jaliscoensis RADWIN & D’ArTILIO, spec. nov. protoconch, greatly enlarged THE VELIGER, Vol. 12, No. 3 [Rapwin & D’Artixio] Plate 52 Figure 1 Figure 2 Figure 3 Figure 4 Figure 5 Figure 6 Vol. 12; No. 3 the Pliocene of Italy. Although this name has often been used for M. blainvillei, we have been unable to come to a firm conclusion concerning its status. We have never seen a bona fide Recent specimen of Murex cristatus and, there- fore, any statement on this matter would enter the realm of conjecture. If Murex cristatus were to be shown to be the same as Muricopsis blainvillei, the former name would, of course, have priority and the latter would be considered a junior synonym. We have not seen the type of Murex blainvillei, said by Dance (1966, p. 297) to be in the Paris Museum, but there is little doubt about the identity of this species, figured many times in the literature (PAYRAUDEAU, 1826; GrancER, 1884; Locarp, 1892). Muricopsis jaliscoensis Rapwin & D’ATTILIO, spec. nov. (Plate 52, Figures 4, 5) Description: Shell light brown; length 26.5 mm; 6 whorls excluding the nucleus; spire high, with 5 spinose varices and sculptured with finely scabrous striae throughout. The nucleus of an immature paratype has 2 whorls; the first whorl is somewhat flat and slightly depressed; the second nuclear whorl is distinctly tabulate (Plate 52, Figure 6). Axial sculpture on the spire consists of conical tubercles at the shoulder, extending axially to preceding whorls as low ridges; areas between these low ridges equal in width and concave; suture very shallow and undulate. Spiral sculpture on the body whorl consists of primary, secondary, and tertiary elements. There are 5 primary cords, 4 equidistant cords and a fifth, more distant one on the canal. Each of these ends in a short varical spine; spines increase in length toward the final varix. The vari- cal edge is obliterated except on the last 3 or 4 varices. Between the primary cords are 1 or 2 secondary cords, also ending in tiny spines. Interspersed between the primary and secondary elements are numerous fine tertiary threads, imbricated with close-set scales, present also on the vari- cal spines. In addition, the shoulder has about 10 spiral cords of secondary strength. The spiral cords on the spire are the same size and development as those on the body whorl. The color of the entire skell is an even tone of yellow-brown. The aperture is of moderate size; situated below the median area of the shell; is white to bluish white; ovate; with a posterior anal groove; the inner sur- face of the apertural lip has 7 denticles, arranged as follows: a large knob-like one near the anal groove; be- low this, occupying the remainder of the lip are 6 den- ticles; the center 4 set more closely together, the remaining 2 somewhat more distant, 1 on each side of the central 4. The columellar edge is slightly erect anteriorly. On the THE VELIGER Page 353 columella, directly above the siphonal canal are 3 conti- guous denticles in a posterior-anterior orientation, the posterior one most prominent. The siphonal canal is mod- erately long, narrowly open and recurved; the siphonal fasciole bears the short distal portions of 3 previous canals. Description of the radula: Each transverse radular row has a single rachidian tooth, flanked on each side by a simple, sickle-like lateral tooth (Text figure 2). The base of the rachidian tooth is roughly rectangular with a prom- inent, downward pointing projection at each end of the rectangle and 5 sharp cusps. The lateral cusps are moder- ately long and sharp. The intermediate cusps are as sharp but only half as long and are positioned closer to the lateral cusp than to the central. The central cusp is un- usually large and strong and is borne on a cowl-like structure. This structure enables it to project further out- ward and downward than any of the other cusps. Because of the great distance that this cusp projects in advance of the others, it is impossible, at the desired high magni- fication, to bring it into focus simultaneously with the remainder of the cusps. Measurements: holotype — length, 26.5 mm; width, 13.8 mm; largest paratype — length 27.3 mm; width, 16.5 mm (lacking protoconch) ; smallest mature paratype — length, 22.2 mm; width, 12.0 mm. Type locality: Bahia Coastocomate, Jalisco, Mexico, in 20 - 70 feet, Lawrence E. Thomas, January, 1969 (holo- type, see Plate 52, Figure 4; and 4 paratypes). Type depositories: holotype, SDNHS no. 51251; 4 para- types, SDNHS no. 51250, January, 1969 (Plate 52, Figure 5), both from type locality; 3 paratypes, SDNHS no. 51015, March 1, 1969 (specimen from which figured radula was extracted), Puerto Vallarta, Jalisco, Mexico, 2 mature, 1 immature; 1 paratype, SDNHS no. 51285, October 19, 1968, Coastocomate, Jalisco, Mexico, mature; 22 paratypes, 5 mature, 17 immature, LACM no. 65-15, March 22, 1965, Los Arcos, Banderas Bay, Jalisco, Mexi- co; 30 paratypes, 18 mature, 12 immature, LACM no. 65-14, March 21, 1965, Tres Marietas Islands, Banderas Bay, Jalisco, Mexico; 5 paratypes, all mature, AMNH no. 153349, February 1, 1969, Barra de Navidad, Jalisco, Mexico (dead specimens) . Remarks: The holotype is a fresh, live-taken specimen, as are all but 5 of the paratypes (see above). The 5 para- types deposited at the American Musuem of Natural His- tory are dead-collected but rather fresh. From a zoogeographic viewpoint the distribution of this species is narrowly restricted, on the basis of our present knowledge. It is found mainly in the area between Ban- deras Bay (Puerto Vallarta) and Manzanillo. This portion Page 354 THE VELIGER Vol. 12; No. 3 a ee es, So ey Figure 2 Muricopsis jaliscoensis Rapwin & D’ATTILIO, spec. nov. one lateral and one central tooth from the radula of a paratype (SDNHS no. 51015) of Mexico has not, apparently, been sufficiently explored for its molluscan species. Although the new species is not rare, and found in fairly shallow water, the lack of collect- ing in this relatively small area of the West Mexican coast may account for its not being discovered until the last few years. It is most closely allied in size and form to Muricopsis zeteki HERTLEIN & STRONG, 1951 (Plate 52, Figure 1), a widespread species occurring from the Gulf of California to Ecuador and Galapagos. Muricopsis ze- teki differs, however, in its more slender overall appear- ance and its more spinose character. In the area in which both species occur, the spines and primary spiral cords of M. zeteki are whitish, the interspaces between the spines are dark brown to black, and the remainder of the shell is yellow-tan. One other species, M. armatus (A. ApaMS, 1854) (Plate 52, Figure 2) needs to be considered in this context. The distribution of M. armatus is from the upper portion of the Gulf of California to Mazatlan, Mexico, with dubious records from Nicaragua and Pana- ma. Its distribution does not seem to overlap that of M. jaliscoensis. Muricopsis armatus is whitish to pale yellow - or brown in color; it is larger (18 - 47 mm) and in areas of optimal conditions the spines are long and sharp. The shoulder is well defined. The inner surface of the apertural lip has 5 to 7 denticles, depending on the size of the indi- vidual. On the anterior columellar edge there are 2 denticles; 1 at the mouth of the aperture and 1 recessed more deeply. In the aperture of all these species, one may find a quick diagnostic feature for their separation. Muricopsis zeteki has 5 denticles within the apertural lip, a posterior knob-like denticle near the anal groove, a second large denticle below this, followed by 3 smaller denticles. In addition, on the anterior end of the columella are 2 con- tiguous, elongate denticles. The first is the larger, and with the second one, situated more deeply within the aperture, forms a continuous ridge extending into the aperture for a considerable distance. Anterior to this structure there is a strong groove followed by a raised, rounded ridge at the end of the columella. In Muricopsis armatus the inner surface of the apertural lip bears 5 to 7 equidistant denticles and on the columellar edge are 2 denticles, 1 at the mouth and the second re- cessed more deeply into the aperture. Vol. 12; No. 3 THE VELIGER Page 355 Figure 3 Muricopsis blainvillei (PAYRAUDEAU, 1826) operculum, interior and exterior In Muricopsis jaliscoensis, as noted earlier, there are, consistently, 7 denticles on the inner surface of the aper- tural lip; a large, knob-like one near the anal groove, at some distance from this another denticle of moderate strength, after another space a series of 4 closely spaced denticles, and the final, anterior-most denticle after an- other gap. On the columella, directly above the siphonal canal, are 3 contiguous denticles in a posterior-anterior orientation; the posterior one most prominent. ACKNOWLEDGMENTS We gratefully acknowledge our debt to the following friends and colleagues for courtesies of various kinds in the preparation of this paper: Dr. William K. Emerson, Dr. James H. McLean, Mr. Lawrence E. Thomas, Mrs. Twila Bratcher, Dr. Donald R. Shasky, Mrs. Ruth Purdy, and Mr. and Mrs. Carl Shy. We especially wish to thank Mr. Dallas Clites for his outstanding photographic work. LITERATURE CITED ApaAMSs, ARTHUR 1854. Descriptions of new shells from the collection of H. Cuming, Esq. Proc. Zool. Soc. London for 1853 (prt. XXI) : 69 - 74 (25 July 1854) Apams, Henry, & ARTHUR ADAMS 1853-1858. The genera of Recent Mollusca, arranged according to their organization. London; 1: vi-xl, 1-484; 2: 1-661: 3: pits. 1 - 138 Bivona-BERNARDI, ANTONIO 1882. Caratteri di un nuovo genere di conchiglie della famig- Figure 4 Muricopsis jaliscoensis Rapwin & D’ArTILIO, spec. nov. operculum, interior and exterior lia delle Columellarie del Signor Lamarck. Effem. Scient. Lett. Sicilia 2: 8- 12 {not seen] Broccui, GIovANNI BaTTISTA 1814. Conchologia fossile subapennina ... vol. 2; Milan, Silvestro; 556 pp. Bucqguoy, EucENE & PHILippE DAUTZENBERG 1882. in: Bucguoy, DauTZENBERG « DottFrus, Mollusques marins du Roussillon. Paris, vol. 1. fasc. 1. Genres: Murex, Pisania, Ranella, Triton, Cancellaria, Hadriania, Fusus, Euthria, and Trophon, pp. 1 - 40; atlas plts. 1-5 CarPENTER, PHILIP PEARSALL 1865. | Diagnoses of new species of mollusks, from the west tropical region of North America, principally collected by the Rev. J. Rowell, of San Francisco. Proc. Zool. Soc. London (for 1865) (1): 278-282 (June) [reprinted in CaRPENTER, 1872 (I): 269-275] CossMANN, ALEXANDRE EpouARD MAURICE 1903. Essais de paléoconchyliologie comparée, vol. 5 (Paris) (chez l’auteur): 215 pp.; 9 plts.; 16 text figs. Dance, STANLEY PETER 1966. Shell collecting: an illustrated history. Press, Berkeley & Los Angeles, 344 pp.; 35 plts. Dittwyn, LEwis WESTON 1817. A descriptive catalogue of Recent shells arranged according to the Linnaean method, with particular attention to the synonymy. London, 1: 1 - 580; 2: 581 - 1092; index GMELIN, JOHANN FRIEDRICH 1791. Caroli Linnaei systema naturae per regna tria naturae. Ed. 13, aucta, reformata, Vermes Testacea Lipsiae 1 (6). pp. 3021 - 3910 GRANGER, A. 1885. Histoire naturelle de France. pt. 6, Mollusques (Cephal- opodes, Gasteropodes). Paris. [not seen] HEILPRIN, ANGELO 1887. Explorations on the west coast of Florida and in the Okeechobee wilderness. Trans. Wagner Free Inst. 1: 1 to 134; 19 plts. Univ. Calif. THE VELIGER Page 356 HErTLeEIN, LEo GeorcE & ARCHIBALD McCLureE STRONG 1951. | Eastern Pacific expeditions of the New York Zoological Society. XLIII. Mollusks from the west coast of Mexico and Central America; PartsI-X. Zoologica, prt. 10; 36: 67 - 120; pits. 1-11 (20 August 1951) KEEN, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford Univ. Press, Stanford, Calif. (5 December 1958) LAMARCK, JEAN-BAPTISTE PIERRE ANTOINE DE MONET DE 1822. Histoire naturelle des animaux sans vertébres, 7 [Mol- lusques]. Paris (“‘chez l’auteur, au jardin du Roi”) pp. 1-711 (August 1822) Locarp, ARNOULD 1892. Les coquilles marines des cétes de France, descriptions des familles, genres et espéces. Paris; 384 pp. MonTEROSATO, Tommaso pi Maria ALLERI 1878. | Enumerazione e sinonimia delle conchiglie Mediterranee . pt. 1, Palermo [not seen] Mé6rcu, Orro ANpREAs Lowson 1852-1853. Catalogus conchyliorum quae reliquit D. Alphonso d’Aguirra et Gadea, Comes de Yoldi. Hafniae, fasc. 1: 1-170 WENZ, WILHELM 1941. Gastropoda Vol. 12; No. 3 Patias, PETER SIMON 1774. Specilegia zoologica .. PaYRAUDEAU, B. C. 1826. Catalogue descriptif et méthodique des annelides et mollusques de I’Ile de Corse. 218 pp.; 8 plts. [not seen] Risso, ANTOINE 1826. Histoire naturelle des principales productions de l’Europe méridionale et particuliérement de celles des environs de Nice et des Alpes maritimes; ... 4. Paris (R-G. Levrault) pp. i- vii+1 - 439; plts. 1-12 Sowersy, GeorcE BRETTINGHAM (2%? of name) 1834. The conchological illustrations, Murex catalogue, prt. 61, p. 8; plt. 61, spec. 23 Swainson, WILLIAM 1840. A treatise on malacology; or the natural classification of shells and shell-fish. London, i - viiit1-419; 130 text figs. (May 1840) ., fasc. 10, Berolino [not seen] TaTE, RALPH 1888. The gastropods of the older Tertiary of Australia. (Part 1). Trans. and Proc. and Report, Roy. Soc. South Aus- tralia, for 1886 - 1887, 10: 91-176; plts. i - xiii. [not seen] in O. H. Schindewolf (ed.): Handbuch der Paldozoologie. Berlin, vol. 6, prt. 5: 961 - 1200 Woop, WILLIAM 1828. Supplement to the Index Testaceologicus or a catalogue of shells, British and foreign. London, W. Wood. 59 pp.; 8 plts. index to plates: 34 pp. s Vol. 12; No. 3 THE VELIGER Page 357 Two New Species of Deepwater Bivalves from the Caribbean Sea H. E. VOKES Department of Geology, Tulane University, New Orleans, Louisiana 70118 (Plate 53; 2 Text figures) AMONG THE SEVERAL INTERESTING species of bivalve mol- lusca secured by the U. S. Fish and Wildlife M/V Oregon II during a recent program of fisheries investigations in the Caribbean Sea were a pair of fresh valves of Solemya (Acharax) and a complete specimen, with animal, plus a worn right valve of a large species of Lima (Acesta). Both proved to be undescribed species, and both represent the second species of their respective subgenera to be recorded from the waters of the western Atlantic Ocean. All were secured in one shrimp net trawl from Oregon II station 10288, at latitude 11°27’ N, longitude 73°42’ W, about 20 miles off the coast of Colombia, South America, at a depth of 220 fathoms. Judging from small amounts of adhering matrix, the bottom sediment was composed of greenish-grey mud. The writer is greatly indebted to Mr. Harvey R. Bullis, Base Director of the Pascagoula, Mississippi Station of the Fish and Wildlife Service for permission to study and describe these specimens. SOLEMYIDAE Gray, 1840 Solemya Lamarck, 1818 Type species, by SD (Cuitpren, 1823) ““Solenomya” [= Solemya] Mediterranea LaMarck = Tellina to- gata Pout, 1791 + solen (Von Saus, 1793). Recent, Mediterranean and Adriatic Seas. For synonymy and a discussion of the problem of fixing the type species of Solemya, see Vokes, 1955, which also includes a list of known Tertiary and Recent species. (Acharax) Dax, 1908 Type species, by OD, Solemya johnsoni Datt, 1891. Recent, Eastern Pacific. The subgenus Acharax Datu includes those large, usu- ally deep water species of Solemya with a wholly external, opisthodetic ligament. Solemya (Acharax) caribbaea H. E. VoKEs, spec. nov. (Plate 53, Figures 1, 2; Text figure 1) The shell is heavy for the genus, large, elongate, strongly inequilateral, widely gaping anteriorly, with the anterior end much longer than the posterior and with broad, low and inconspicuous umbones located slightly behind the posterior third of the total length. It is covered by a strong, blackish-brown periostracum that is produced beyond the margins of the shell, especially anteriorly and ventrally, and is continuous dorsally over the gap between the two valves which do not contact each other except in the area immediately between the umbos. This periostracum is translucent and of a dark amber tint in the portions that project beyond the shell; in the posterior and postero- ventral areas it is produced into ragged finger-like proces- ses that are prolongations of that portion of the structure covering the wide inter-rib areas of the valve surface, with the re-entrants between the processes making the areas where the periostracum lies over the broad primary ribs on the valve. In the median areas of the valve, where the rib and interspace ornamentation is not strongly devel- oped, the periostracal projection is not divided. The ante- rior dorsal margin of the valve is long, slightly convex, almost straight, sharply rounded into the anterior end, the upper half of which is straight, the ventral half broadly and regularly rounded into the very slightly concave vent- ral margin which, posteriorly, curves gently into the arcu- ate posterior margin. The posterior dorsal margin is marked by a low narrow ridge that rises vertically above the adjacent outer valve surface, straight in the area behind the nymph plate, slightly arcuate laterally around Page 358 THE VELIGER Vol. 12; No. 3 that plate to leave a groove for the reception of the liga- ment, then curving upward to terminate immediately behind the umbo. The dorsal margin is the thickest area of the valve, there being a buttress-like thickening under the anterior half of the nymph plate that extends forward and under the low umbone to fill the sub-umbonal cavity; anterior to this the margin is thickened externally to form a low, round-topped, rib-like structure that extends to the most anterior extremity of the margin. The surface of the valve below this dorsal ridge is ornamented by low broad radial ribs separated by relatively wider interspaces. Three such ribs extend to the anterior end of the valve, while a fourth marks the antero-ventral junction. The tops of these ribs are relatively flat in the younger stages of growth, but in the later stages one or more (usually one) very shallow and broad grooves tend to develop on the rib surface; these are not as sharp nor as well marked as are the interspaces between the ribs. These interspaces are set off from the ribs by relatively narrow and deep round- bottomed channels with the area between the channels slightly convex upward, suggesting low rounded secondary ribs and these, in turn, bear on their upper surface narrow grooves, usually 2 or 3 in number, that serve to delimit narrow, rounded, tertiary rib-like structures. Posterior to the fourth primary rib the median surface of the valve shows a tendency to have broad ribs and interspaces, but there is no marked distinction in the relative height of these structures though the rounded margining grooves persist as do, to a lesser extent, the shallower, less well marked ridges on the central parts of the rib and inter- space area. The postero-ventral margin is marked by 3 relatively wide and flat-topped radial ribs separated from each other by 2 broad interspaces that are approximately of the same width as the adjacent ribs, and like the inter- spaces on the anterior end of the valve are somewhat convex upward in their medial areas. These 3 postero- ventral ribs tend to project very slightly along the valve Figure 1 Solemya (Acharax) caribbaea H. E. Voxss, spec. nov. A: Interior of right valve of holotype. B: Same, but valve tilted to show muscle scars that lie under the dorsal margin aa-c anterior adductor muscle scar, “catch”segment aa-f anterior adductor muscle scar, “fast” segment pa-f and pa-c posterior adductor muscle scar, “fast” and “catch” segments, respectively apr anterior pedal retractor muscle scar ppr posterior pedal retractor muscle scar pe? scar of pedal elevator muscle? (approximately X 1) margin with the interspaces forming slight re-entrants between them. The surface of the valve above the most posterior of the 3 ribs is smooth, marked only by growth lines. Explanation of Plate 53 Solemya (Acharax) caribbaea H.E. VoxEs, spec. nov. Figure 1: Exterior of left valve covered by the ragged, dark brown periostracum Figure 2: Exterior of left valve with periostracum removed (ob- liquely lighted to emphasize radial ornamentation) Holotype USNM 679377 Lima (Acesta) colombiana H.E. Voxes, spec. nov. Figure 3: Anterior view of conjoined valves Figure 4: Exterior of right valve. Holotype USNM 679378 (all figures X 1) THE VELIGER, Vol. 12, No. 3 [H. E. VoxEs] Plate 53 Figure 1 Figure 3 , Heures Vol. 12; No. 3 The paravincular ligament is opisthodetic, with the fibrous resilium seated on a relatively strong nymph plate that rises from the inner side of the thickened margin of the valve and curves upward so that its straight dorsal margin is essentially parallel with the anterior dorsal margin of the valve, though topographically a little lower than the latter. The resilium is attached to the outer sur- face of the nymph and arches over its dorsal side to its attachment in the other valve. The outer lamellar tensil- ium is longer than the resilium projecting posteriorly to it, thick and heavy, set in a distinct groove between the nymph plate and the raised posterior dorsal margin of the valve, and somewhat darker in color than the peri- ostracum to which it is firmly cemented. The interior of the valve is chalky white in color, with the interrib areas of the anterior and the posterio-ventral areas weakly reflected on its surface. The weak ribbing on the external median surface is evidenced only along the ventral margin where the deeper grooves margining the interspaces are represented by low rounded riblets. Anterior adductor scar relatively large, subquadrate in outline, not impressed; posterior adductor smaller, slight- ly impressed. Both scars show differentiation into 2 areas, a smaller outer and a larger inner one that probably re- flect the areas occupied by the “quick” or “fast” muscle segment comprised of striated fibers and those with the “slow” or “catch” muscle segment comprised of smooth muscle fibers. Analogy with other bivalve species sug- gests that the smaller, outer portions of the scars were the seat of the “slow” muscle segments. A narrow, linear series of muscle attachment impressions follows the under side of the thickened dorsal margin extending posteriorly from a point immediately posterior to the anterior adduc- tor scar to approximately the mid-length of the thickened nymph. Small areas set off from the others by a shallow groove, one at the anterior end of this series, the other at the posterior end located upon the edge of the nymph, are, by analogy with the illustrations of the anatomy of Solemya “mediterranea LAMARCK” given by DESHAYES (1845, plate 19, figure 5) attachment areas for the pedal retractor muscles, while the elongate, median scar prob- ably marks the site of the pedal elevator muscle (Text figure 1B). Pallial line not well delimited, but appears to have been entire, non-sinuated. Holotype: U.S. N.M.no. 679377; length (with peri- ostracum) 95mm; (without periostracum) 78.3 mm; height (with periostracum) 47 mm, (without periostra- cum) 32.3 mm; diameter (paired valves) 22 mm. Solemya (Acharax) caribbaea, spec. nov., differs from S. (A.) grandis VERRILL & BusH (1898, p. 885; plt. 86, figs. 1,2), the only other west Atlantic species of Acharax, THE VELIGER Page 359 described from material from 4 dredging localities off the eastern coast of the United States between Maryland and Massachusetts in depths of 300 to 1200 fathoms, in being a larger species, with more posteriorly situated umbones, and with fewer (4) radial ribs on the anterior end, as compared with 6 to 8 on S. grandis. Solemya (Acharax) johnsoni Datu (1891, p. 189; 1895, p. 712; plt. 35, fig. 1) and its probable synonym (see Woonrine, 1938, p. 27), S. (A.) agassizii (DALL, 1908, p. 365; plt. 16, fig. 10) have more numerous radial ribs both anteriorly and on the postero-ventral area, and um- bones that are slightly more anteriorly situated than are those of the present species. Both are apparently larger species. There is, however, some uncertainty as to the dimensions of the type of S. (A.) agassizii; DALL gives the dimensions of the species in his description as: “Length . excluding periostracum, about 95; height 30; and diameter, 25 mm. The species reaches a length of more than 150 mm.” But his figured specimen (plate 16, figure 10), lacking periostracum, is said to be “lon. 145.0 mm.” Wooprine (1938, p. 27) states that “The type of agas- sizi is a large shell ... that has a length exclusive of the periostracum of about 143 millimeters.” Accepting these larger figures, the type of S. (A.) agassizii is almost twice the size of S. (A.) caribbaea. LimméE RaFINESQUE, 1815 Lima Brucutkre, 1797 Type species, by subsequent tautonomy (LAMaRCK, 1801) Ostrea lima Linnarus, 1758 = Lima squa- mosa LAMARCK, 1801. Recent. The writer has discussed in some detail the problems of the authorship and fixation of the type species in an earlier paper (VoKEs, 1963). (Acesta) H. & A. Apams, 1858 Type species, by M, Lima “excavata (CHEMNITZ)” = Ostrea excavata Fasricius. Recent, 150 to 1450 fath- oms, Greenland to the Canary Islands. A few years ago the writer described (VoKEs, 1963, p. 77) under the name Lima (Acesta) bullisi a large species that had been trawled by the Fish and Wildlife Service M/V Oregon from localities 70 miles south-southeast, and 75 miles due south of the entrance to Mobile Bay, Ala- bama, at depths ranging from 300 to 600 fathoms. Subse- quently he has seen, in the private collection of Mrs. Page 360 Mildred Tate of Lake Jackson, Texas, a very fine pair of valves that had been trawled by a shrimp boat from below 226 fathoms off the Mississippi River delta. This species, the first recorded from western Atlantic waters, has, to date, been recorded only from the fauna of the northern part of the Gulf of Mexico. Lima (Acesta) colombiana H. E. VokEs, spec. nov. (Plate 50, Figures 3, 4; Text figure 2) Shell large, elongate ovate in outline, very inequilateral, almost equivalved, with the right valve slightly more in- flated than the left; umbones low, almost terminal ante- riorly, but slightly prosogyrate; anterior ear small, poste- rior elongate, not delimited from rest of valve; hinge line straight, relatively short (approximately 31 mm in length), with a strongly curved ligamental pit that is 11.8mm wide where it intersects the hinge line; elongate lunular area excavate, its outer portion marked by fine, irregular radial ribs, its inner side strongly corrugated by growth lamellae; the anterior margin is broadly concave in the lunular area, but the anterior-dorsal slope of the valve, including the area above the lunule, is almost straight, anterior end rather sharply rounded, ventral and posterior ends broadly and regularly rounded, posterior dorsal slope Figure 2 Outline of right valve of Lima (Acesta) colombiana H. E. VoxEs, spec. nov. (continuous line) compared with that of Lima (Acesta) bullist H. E. Voxes, 1963 (broken line). Both approximately one-half natural size THE VELIGER Vol. 12; No. 3 slightly convex, almost straight, subangulate at the junc- tion with the short, relatively straight dorsal margin. Surface ornamentation characteristic of the subgenus, with, on the median surface of the valve, numerous fine, irregular, round-topped radial riblets of variable width separated by exceedingly narrow irregular grooves; the ribs on the dorsal area so fine as to be visible only under oblique light and magnification, increasing in relative width and strength as the shell becomes larger; number of ribs increases by development of median groove on the rib surface which later assumes the strength of a narrow interspace; laterally the ribs become relatively narrower with progressively wider, rounded interspaces, until near the margin they are best described as low, rounded radial threads with interspaces 3 to 4 times as wide as the ribs. Interior of valve with smooth margins, adductor scar situated relatively high in the valve, rounded to sub-tri- gonal in outline, not impressed, its anterior margin at the mid-width of the valve. Holotype: U.S. N. M. no. 679378, height 124 mm, length 94.8 mm, diameter (paired valves) 60.3 mm. Paratype: U.S.N,M. no. 679378a, height 120mm, length (incomplete) 91.4mm, diameter (right valve) 32.6 mm. Lima (Acesta) colombiana spec. nov. differs from L. (A.) bullisi Voxes in having a shell that is much higher in proportion to its length (see Text figure 2), with a longer and straighter antero-dorsal margin and more sharply rounded anterior end. The surface ornamentation, while characteristic of the subgenus in both forms, is more weakly developed and finer in the new species than in the Gulf of Mexico form, there being 13 to 14 ribs per centimeter on the median area of the valve as compared with 8 to 9 per centimeter in L. (A.) bullist. The Oligocene Lima (Acesta) goajira Otsson & RicH- Arps (1961, p. 6; plt. 1, fig. 1), described from the adja- cent Goajira Peninsula of Colombia, judging from the growth lines, appears to have had a somewhat comparable outline, although the anterior end may have been more broadly and regularly rounded. This form is described, however, as being smooth and devoid of radial omamenta- tion except for a “narrow area of wavy, radial threads along the posterior dorsal margin.” Of the Recent Eastern Pacific species, Lima (Acesta) agassizi DauL, 1902, dredged from 322 fathoms in the Gulf of Panama, has, judging from the illustrations (DALL, 1908, p. 47; plt. 16, fig. 1), a shorter antero-dorsal margin, longer and more broadly rounded anterior end, and coarser radial ornamentation; L. (A.) mori HERTLEIN (1952, p. 379; plt. 20, figs. 12, 13), described from Mul- berry Seamount, off San Mateo County, California, is Vol. 12; No. 3 much more rounded in outline, with very low and ap- parently inflated umbone, and so far as can be judged from the illustration, coarser radial ornamentation. The recently described mid-Pacific Acesta virgo HaBE & OxuTant (1968, p. 51; plt. 3, fig. 8) from 480 meters off Midway Island, has an outline that is quite like that of L. (A.) colombiana with a similarly long and relatively straight antero-dorsal slope and broadly rounded ventral and posterior margins. It differs, however, in its shorter, more obliquely sloping postero-dorsal and shorter dorsal margins. The ornamentation, not well shown in the illus- tration, is described as consisting of regularly spaced radial riblets, a condition that would differ greatly from the irregularity of the ribbing on the present species. LITERATURE CITED Dati, WILLIAM HEALEY 1891. Scientific results of explorations by the U.S. Fish Com- mission steamer Albatross. XX. — On some new or interesting West American shells obtained from the dredgings of the U.S. Fish Commission steamer Albatross in 1888 and from other sources. Proc. U.S. Nat. Mus. 14 (849): 173-191; plts. 5-7 (24 July 1891) 1908. Reports on the dredging operations off the west coast of Central America to the Galapagos, to the west coast of Mexico, and in the Gulf of California. . XIV. The Mollusca and Brachiopoda. Harvard 43 (6): 205 - 487; 22 plts. Bull. Mus. Comp. Zool., (October 1908) THE VELIGER Page 361 DesHAyYEs, GzrRaRD PAuL 1844 [1845] - 1849. Explorations scientifiques de l’Algérie pendant . 1840-1842. ... Zoologie. I. Histoire naturelle des Mol- lusques. Atlas: 160 pp.; 155 col. plts. Paris, France Hase, TADASHIGE & TAKASHI OKUTANI 1968. Some new and interesting shells from the sea around Midway Island. Venus, Japan. Journ. Malacol. 27 (2) : 47 - 56; pit. 3 (October 1968) HERTLEIN, LEO GEORGE 1952. Description of a new pelecypod of the genus Lima from deep water off Central California. Proc. Calif. Acad. Sci. (4) 27 (12): 377 - 381; plt. 20 (11 July 1952) Oxsson, AxEL ADOLF & Horace GARDINER RICHARDS 1961. Some Tertiary fossils from the Goajira Peninsula, Co- lombia. Notulae Naturae no. 350: 1-16; 2 plts. (10 November 1961) VeRRILL, AppISON E. &« KATHARINE J. BusH 1898. Revision of the deep-water Mollusca of the Atlantic Coast of North America, with descriptions of new genera and species. Part I. — Bivalvia. Proc. U.S. Nat. Mus. 20: 775 - 901; plts. 71 - 97 (15 June 1898) VoKEs, Haro_p ERNEST 1955. Notes on Tertiary and Recent Solemyacidae. Paleont. 29 (3): 534 - 545 1963. Studies on Tertiary and Recent giant Limidae. I. A new species of Acesta from the Gulf of Mexico. II. A catalogue of the described and Recent and Tertiary species of Acesta. III. Plicacesta, a new subgenus of Lima. Tulane Stud. Geol. 1 (2): 73-92; 2 plts. (18 January 1963) Wooprinc, WENDELL PHILLIPS 1938. | Lower Pliocene mollusks and echinoids from the Los Angeles Basin, California. U.S. Geol. Survey, Prof. Paper 190: i-ii+ 1-67; 9 plts.; 2 figs. Journ. Page 362 THE VELIGER Vol. 12; No. 3 Descriptions of a New Genus and Eight New Species of Eastern Pacific Fissurellidae, with Notes on Other Species JAMES H. McLEAN Los Angeles County Museum of Natural History goo Exposition Boulevard, Los Angeles, California 90007 (Plate 54; 1 Text figure) THE EASTERN PACIFIC FISSURELLDAE are known chiefly through Pirssry’s monograph in the Manual of Con- chology (1890). More recently the species of the Panamic province were treated by Keen (1958) and those of the northeastern Pacific in a dissertation by McLEan (1966). A comprehensive review of the entire family similar to that for the western Atlantic by FARFANTE (1943a, 1943b, 1947) is not available. Most of the genera discussed by FaRFANTE are represented in the eastern Pacific and these papers are of considerable value for comparison. In assisting with the treatment of Fissurellidae for the forthcoming revised edition of “Seashells of Tropical West America,” by Dr. Myra Keen, I have realized that there is a need for the description of a new genus and several new species. These descriptions are presented here. Five of the new species are from the tropical Panamic faunal province, while 3 are from the south temperate Peruvian province. Two of the Panamic species are from the Galapagos Islands, approximately 600 miles west of Ecuador. The 3 species from the Peruvian province are from the offshore Chilean island groups Juan Fernandez and San Felix. These islands bear much the same relation- ship to the Peruvian province as do the Galapagos Islands to the Panamic province. Many of the species are en- demic. ODHNER (1922) listed 39 species from shallow water at the Juan Fernandez Islands, 50% of which were endemic. Very little is known of the offshore mollusks of the Chilean islands. The 3 species described herein result from collecting on the Anton Bruun Cruise 17 that visited these islands in July 1966. Institutions mentioned in the text and their abbrevia- tions are as follows: AHF - Allan Hancock Foundation (gastropod collec- tion on loan to LACM) CAS - California Academy of Sciences, San Francisco LACM -— Los Angeles County Museum of Natural History SU — Stanford University, Stanford, California USNM - United States National Museum, Washington, D. C. Tugalt chilensis McLean, spec. nov. (Plate 54, Figures 8, 9) Description of Holotype: Shell small, elongate ovate, with nearly parallel sides, moderately elevated. Apex blunt, nucleus worn smooth, directed posteriorly, + the length of the shell from the posterior margin. Anterior slope convex, posterior slope concave, sides nearly flat. On a level surface the sides of the shell are slightly raised relative to the ends. Sculpture consists of radial and con- centric ribbing of nearly equal strength, beaded at inter- sections and producing indistinct square cancellations. Concentric growth irregularities are also apparent. Ap- proximately 30 primary ribs diverge from the apex and secondary ribs appear at half its final size, resulting in about 60 ribs of identical size and strength that wrap around the thick margin of the shell. No selenizone or crenulation apparent at the anterior margin. Interior of holotype encrusted, characters of muscle scar not discern- ible. Length, 10.4mm, width 6.5mm, height 3.8mm (holotype) . Type Material: Holotype, LACM 1306. Type Locality: Carvajal Bay, south end of Isla Mas a Tierra, Juan Fernandez Islands, Chile, 34°50’S, 79°00’ W. A single dead specimen was collected at low tide by Mr. Roger Seapy of the University of Southern California, 17 July 1966, Anton Bruun, Cruise 17. Discussion: Although represented by but a single shell in poor condition, it is adequate for subsequent recognition and its description emphasizes the presence of this Austral- asian genus in the Eastern Pacific fauna. Tugali chilensis Vol. 12; No. 3 is a species closely related to T: suteri THEE, 1916, of the New Zealand fauna. Specimens of the latter species on hand are slightly larger, have more numerous ribs and the apex at 3 the distance from.the posterior margin. The Juan Fernandez Islands are approximately 400 miles west of the mainland of Chile at the latitude of Valparaiso. Nesta galapagensis McLean, spec. nov. (Plate 54, Figures 18, 19) Description of Holotype: Shell small, white, base elongate ovate. Nucleus extremely minute, at the posterior end of the shell just above the margin, twisted to the right (in apertural view). The anterior face of the shell forms the entire dorsal surface, the posterior face represented by a narrow shelf, as in the hinge area of a bivalve. A fairly broad selenizone extends from the nucleus to the anterior margin, bounded by raised ridges and provided with U- shaped incremental lines. Sculpture consists of numerous radial and concentric ribs of equal strength, forming squarish cancellations. The radial ribs on crossing the concentric ribs are drawn out in blunt lamellar points, visible only in lighting from the direction of the apex. Entire anterior margin broken in holotype. Interior glossy, with heavy callus deposition along the line of the seleni- zone. Length, 5.5mm, width, 3.3mm, height 1.7mm (holotype). Type Material: Holotype, LACM - AHF 1307. Type Locality: Tagus Cove, Albemarle (Isabella) Island, Galapagos Islands, Ecuador, 0°16’S, 91°22’30” W, 80-100 fathoms, Velero III bottom sample station 432, 15 Janu- ary 1934, 1 specimen. Discussion: Nesta galapagensis is the first reported spe- cies of Nesta H. Apams, 1870, in the Eastern Pacific. According to FARFANTE (1947, p. 98) there are two other species of Nesta, the strongly sculptured type species, N. candida H. Apams, 1870, from the Red Sea, and the nearly smooth sculptured N. atlantica FARFANTE, 1947, from Florida. Having concentric sculpture, N. galapag- ensis is therefore closer to the type species, but the apex in that species curves below the posterior margin. Emarginula Lamarck, 1801 The genus Emarginula was unknown in the Eastern Pacif- ic until the description of E. velascoensis SHasxy, 1961, from the Gulf of California (SHasxy, 1961, p. 18). THE VELIGER Page 363 A second tropical west American species represented by 4 specimens from the Galapagos Islands and Colombia taken at depths of 45 to 100 fathoms answers the descrip- tion of E. tuberculosa Ligassi, 1859, given by FARFANTE (1947, p. 100; plt. 44, figs. 1-7). This is a relatively large species, the largest specimen from 45 fathoms, off Octavia Rocks, Colombia, measures 13.4 mm in length and 7.2 mm in height (Plate 54, Figures 10, 11). Sculp- ture consists of numerous fine radial and concentric ribs producing beaded intersections and deep square pits. Every 4" rib at the margin, each of which represents an original primary rib diverging from the apex, is slightly more prominent than adjacent secondary ribs, as in FARFANTE’S illustrations. No essential points of difference can be de- tected. Emarginula tuberculosa is also represented in the eastern Atlantic off Portugal and the Azores and its type locality is the Sicilian Miocene. It is therefore a species of considerable antiquity and broad distribution else- where; its presence in the Eastern Pacific is not unex- pected. Descriptions of two additional eastern Pacific species follow. These two species were taken in the same dredge haul at a depth of about 90 fathoms at San Felix Island, approximately 550 miles off the coast of central Chile, and therefore are members of the south temperate or Peruvian faunal province. An anatomical observation pertaining to at least two species of Emarginula may be made here. Cowan (1969) observed that in Fissurisepta pacifica Cowan, 1969, the ctenidium is monopectinate and attached to the roof of the mantle cavity, a condition not previously reported in Fissurellidae. One specimen of E. tuberculosa from Tagus Cove, Isabella Island, Galapagos has a dried animal and the holotype of E. angusta, new species, also has the animal dried in place. Both specimens have monopectin- ate ctenidia resembling those illustrated by Cowan, suggesting that this structure of the ctenidium may be more widespread in the emarginuline fissurellids than has been supposed. Emarginula angusta McLEAN, spec. nov. (Plate 54, Figures 14, 15) Description of Holotype: Shell small, sturdy, yellowish white, base elongate-oval, with nearly parallel sides; height about 3/5 the length, apex posterior, directly above the posterior margin of the shell. Anterior slope broadly convex, posterior slope convex below the apex, sides of shell nearly straight. Nucleus minute, turned under the succeeding part of the shell. Sculpture consists of 16 strong primary cords diverging from the apex; secondary Page 364 THE VELIGER Vol. 12; No. 3 cords develop on the anterior and lateral slopes and reach nearly the strength of the primary cords at the margin; concentric sculpture consists of raised ridges that reach only half the thickness of the primary ribs but form beads at intersections and deep squarish pits. Margin crenulated by rib extensions. The slit is long and narrow, about 1/5 the length of the anterior slope; the lamellae along the fasciole are thickened, equal in number and thickness to the concentric ridges. Interior glossy, dried animal re- maining in the shell. Length, 6.8mm, width, 4.6 mm, height, 4.1 mm (holotype). Type Material: Holotype, LACM 1308. Type Locality: Off San Felix Island, Chile, 26°20’ S, 80°02’ W, 170-160 meters (93-87 fathoms), Anton Bruun, Cruise 17 station 676B, Menzies trawl, 12 July, 1966, 1 specimen. Discussion: Emarginula angusta differs from other East- ern Pacific and Western Atlantic species in having an elongate and narrow basal outline, hence the name, mean- ing narrow. Other species have a more oval basal outline. In addition, the lamellae of the fasciole in E. angusta are broad and thick, unlike the other species that have thin lamellae. Emarginula dictya McLEan, spec. nov. (Plate 54, Figures 16, 17) Description of Holotype: Shell small, fragile, white, base ovate, height about 4 the length, apex posterior, directly above the posterior margin of the shell. Anterior slope convex, posterior slope flat sided below the apex. Nuc- leus minute, greatly overhung by the succeeding part of the shell. Sculpture consists of 20 primary cords diverg- ing from the apex; secondary cords develop on the anterior and lateral faces but do not reach the strength of the primary cords at the margin; concentric sculp- ture consists of narrow raised ridges that do not cross the primary ribs. Margin crenulated by rib extensions. The slit is long and narrow, almost 4 the length of the anterior slope; the lamellae along the fasciole are thin, raised nearly to the margins of the fasciole. Interior glossy, thickened near the slit, anal fasciole marked by thickened callus. Length, 4.6mm, width, 3.6mm, height, 2.3 mm (holotype). Type Material: Holotype, LACM 1309; 1 paratype LA CM 1310. Type Locality: Off San Felix Island, Chile, 26°20’S, 80°02’ W, 170-160 meters (93-87 fathoms), Anton Bruun, Cruise 17 station 676B, Menzies trawl, 12 July, 1966, 2 dead and slightly broken specimens. Discussion: Emarginula dictya differs from the 3 other eastern Pacific species of Emarginula in having weak concentric ribbing and consequently lacking the beaded sculpture at intersections of the ribs. It resembles E. sicula Gray, 1825, of the Western Atlantic and Mediterranean. Emarginula sicula, however, is larger, more elevated, and the apex is near the summit rather than below the mid-height position as in E. dictya. The name is derived from the Greek noun, dictyon, net, with reference to the fine reticulate sculpture. Rimula DrEFrRance, 1827 The genus Rimula was established in the Eastern Pacific with the description of R. californiana Berry, 1964 from Catalina Island. As this species has not been illustrated, the holotype is figured here (Plate 54, Figure 3). Addi- tional specimens are known from Guadalupe Island (LA CM 65-42) and San Martin Island, Baja California (CAS 24041), at depths of 10-20 fathoms on gravel bottoms. KEEN (1968, p. 403) showed that Rimula mazatlanica CaRPENTER, 1857, represents a juvenile Diodora. A second eastern Pacific Rimula may now be added. Explanation of Plate 54 Figures 1, 2: Fissurella (Cremides) decemcostata McLean, spec. nov. Holotype LACM no. 1313. Acapulco, Mexico XK 14 Figure 3: Rimula californiana Berry, 1964. Holotype, SU 9500. Catalina Island, California X6 Figure 4: Rimula astricta McLEan, spec. nov. Holotype USNM no. 267019. San Esteban Island, Mexico x6 Figures 5, 6, 7: Diodora punctifissa McLean, spec. nov. Holotype LACM - AHF no. 1311. Wenman Island, Galapagos Islands X 4 Figures 8, 9: Tugali chilensis McLzan, spec. nov. Holotype LACM no. 1306. Juan Fernandez Islands, Chile. x4 Figures 10, 11: Emarginula tuberculosa Lrpassi, 1859. AHF no. 431-35. Octavia Rocks, Colombia X2 Figures 12, 13: Leurolepas roseola McLEan, spec. nov. Holotype LACM - AHF no. 1315. Tres Marias Islands, Mexico X 3 Figures 14, 15: Emarginula angusta McLEan, spec. nov. Holotype LACM no. 1308. San Felix Island, Chile x5 Figures 16, 17: Emarginula dictya McLean, spec. nov. Holotype LACM no. 1309. San Felix Island, Chile X5 Figures 18, 19: Nesta galapagensis McLEan, spec. nov. Holotype LACM no. 1307. Isabella Island, Galapagos Islands x5 Tue VELIGER, Vol. 12, No. 3 [McLean] Plate 54 Figure 2 Figure 13 Figure 14 Figure 15 Figure 16 Figure 17 Figure 18 Figure 19 . ry = u ‘ a oa = =e ae on == z if foe. SES koe ee x a Es. - - = e . mas ipa) : i x ¥ Baw < cr ii 3 ae i. - “ me = 2 = > vay = a ey a be ‘7 y 7 we : oe e \ Vol. 12; No. 3 Rimula astricta McLean, spec. nov. (Plate 54, Figure 4) Description of Holotype: Shell small, fragile, white, base elongate-ovate, with nearly parallel sides; height less than 4 the length. Anterior slope convex, posterior slope con- cave. Nucleus of one small whorl, placed 1/6 the length of the shell from the posterior margin. Fissure small, its squared off posterior extremity at mid position on the anterior slope, its anterior extremity drawn out into a long tapered slit. Fasciole extending from apex to fissure, provided with lamellae, fissure and fasciole bordered by raised ridges which coalesce anterior to the fissure. Sculp- ture consists of approximately 32 primary ribs, crossed by concentric ridges of nearly equal strength, weakly beaded at intersections and forming deep squarish pits; a few secondary ribs arise but do not reach the strength of the primary ribs at the margin. Margin finely crenulated by rib extensions. Interior lustrous, translucent, the concent- ric sculpture and fasciole of the outer surface visible from within, Length. 5.3 mm, width, 3.3 mm, height, 1.9 mm (holotype). Type Material: Holotype, USNM 267019. Type Locality: East side of San Esteban Island, Gulf of California, 28°41’ N; 112°34’ W. The single specimen was collected by Paul Bartsch, 13-14 April, 1911. Referred Material: LeRoy Poorman Collection, Pasa- dena, California, 1 specimen dredged at 17 fathoms off San Carlos Bay, Guaymas, Sonora, April, 1965. This spe- cimen has a large hole in the shell but the margin is intact. It measures: length, 6.4mm, width, 3.9mm, height, 2.0 mm. Discussion: Rimula astricta differs from R. californiana in having a sharp rather than blunt anterior termination of the fissure. This is the most distinctive feature of R. astricta, upon which the name, meaning drawn together, tight, or narrow, is based. Rimula astricta also has a more elongate basal outline. The only elongate western Atlantic species is R. frenulata Dati, 1889, but this spe- cies does not have the pointed fissure nor the coalesced ribs anterior to the fissure. Diodora punctifissa McLEaN, spec. nov. (Plate 54, Figures 5 to 7) Description of Holotype: Shell small, sturdy, white, base oval, sides of shell raised relative to the ends, height about 2 of the length. Apex intact, blunt pointed, erect, THE VELIGER Page 365 about 4 the length of the shell from the front margin. Fissure small, just anterior to the apex, anterior end of fissure rounded, posterior end broader. Sculpture consists of about 30 primary ribs originating on the apex; second- ary ribs emerge close to the apex and assume nearly equal strength at the margin. Concentric sculpture of weak ridges, somewhat irregular ; cancellate pitting strong- ly developed only on the early growth stage of the shell. Interior callus broad, extending more than + the length of the shell, markedly truncate posteriorly. Length, 9.5 mm, width, 7.0 mm, height, 6.0 mm (holotype). Type Material: LACM -—AHF 1311; 5 paratypes, LA CM —- AHF 1312; 1 paratype, CAS 13276; 1 paratype, USNM 679561. Type Locality: Off Wenman Island, Galapagos Islands, Ecuador, 1°23’10”N, 91°48’45” W, 100-150 fathoms, Velero III station 143-34, 11 January 1934, 8 dead speci- mens. The paratype specimens are immature, the largest measures 7.6mm in length. The species may live at a lesser depth. Discussion: Diodora punctifissa differs from all species of Diodora known to me in having a fully intact apex, not absorbed by the fissure. The fissure is extremely small and is located on the anterior slope of the shell as in the genus Puncturella. The posteriorly truncate internal cal- lus possessed by D. punctifissa is the main diagnostic feature of Diodora. Other species of Diodora having partially intact apices are known. The name meaning small cleft calls attention to the smallness of the fissure. Fissurella (Cremides) decemcostata McLEAN, spec. nov. (Plate 54, Figures 1, 2) Description of Holotype: Shell of medium size, sturdy, depressed. Fissure just forward of center, oblong, faintly tripartite, about 1/9 the length of the shell. Sculpture of 10 broad, raised, nodular ribs, the 2 anterior ribs closely adjacent. The ribs project at the margin, lines connecting their terminations are slightly concave. Fine irregular striae are present on the rib surfaces and interspaces. Concentric sculpture limited to growth irregularities, re- sulting in broad nodules on the ribs. Color whitish, the channels separating the fine riblets dark brown where the surface is not worn smooth. Interior glossy, greenish white, callus area blue gray, bordered with reddish brown, inte- rior with reddish brown stains extending anteriorly and posteriorly from the callus to the edge of the muscle im- pression scar. Length, 28.2 mm, width, 18.5 mm, height, 5.8mm (holotype). Page 366 Type Material: Holotype, LACM 1313; 1 paratype, LA CM 1314; 1 paratype, USNM 679562. Type Locality: Playa Caleta, Acapulco, Guerrero, Mexi- co, 16°51’ N, 99°55’ W. The type lot consisting of 3 speci- mens was collected by the late Earl C. Huffman, 18 December, 1937. Referred Material: Numerous lots are in museum collec- tions from the Tres Marias Islands, Mexico (LACM 65-13), to Oaxaca, Mexico. The species occurs on flat, exposed reefs in the intertidal zone. The upper surface is frequently abraded and usually covered with dense tufts of red algae. Discussion: Fissurella decemcostata is the only eastern Pacific species having primary sculpture of 10 broad ribs. Fissurella microtrema SowErRByY, 1835, is a closely related species sharing the same habitat but this species typically has 3 strong anterior ribs and irregular strong ribbing throughout. The only other species having the irregular purple staining in the interior is F rubropicta Pitssry, 1890, but it differs in having a more elevated shell with strong ribbing throughout. The irregular purple staining of F decemcostata is invariably present and immediately serves to separate shells from F microtrema. Leurolepas McLean, gen. nov. Type Species: Leurolepas roseola McLEan, spec. nov. Diagnosis: Shell small, moderately elevated, basal outline oblong, sides nearly parallel; margin in one plane, aper- ture large, oval, just anterior to center, radial sculpture lacking, concentric sculpture of thin, raised lamellae; col- or reddish brown with darker rays; margin thick, rounded, smooth; apertural callus narrow, encircled by a distinct suture; muscle attachment area close to internal margin. Animal not capable of retracting within the shell, 14 times the length of the shell (preserved), mantle envelop- ing the shell margin on all sides, covering } the area of the shell, extending down to cover the head and foot, surface of mantle with minute pustules, pigmentation pattern matching that of the shell; snout 4 the length of the tentacles, sides of foot weakly pigmented, with an epipodial row of tongue-shaped papillae. Radula fissurelline, rachidian tooth similar in size and shape to the adjacent lateral teeth, outermost lateral large, bicuspid. Discussion: The small rachidian tooth of Leurolepas ’ serves to place it in the subfamily Fissurellinae as delim- ited by THIELE, 1929, in company only with the genus THE VELIGER Vol. 12; No. 3 Fissurella BrucuttrE, 1789, and such Australasian genera as Amblychilepas Pitspry, 1890, and Macrochisma G. B. Sowersy, 1839, in which the animals are also not capable of retraction within the shell. The other eastern Pacific and western Atlantic genera with large animals such as Fissurellidea Orsicny, 1841, Lucapina G. B. SowERsy, 1835, Lucapinella Prtspry, 1890, Megathura Pissry, 1890, and Megatebennus Puspry, 1890, all have an extremely broad rachidian tooth and are thereby relegated to the subfamily Fissurellidinae as delimited by McLEAN (1966). The presence of a member of this otherwise Australasi- an group of genera in the Eastern Pacific is noteworthy. Leurolepas differs from Amblychilepas and Macrochisma and subgenera thereof treated by Moore (1960) in having the margin of the shell not greatly thickened internally and in having a margin resting entirely in one plane, rather than raised at both ends. On shell characters it differs from all other eastern Pacific fissurellid genera in lacking radial ribbing. The name is derived from the Greek words leuros, smooth, and lepas, limpet, suggested by the lack of radial sculpture. Leurolepas roseola McLean, spec. nov. (Plate 54, Figures 12, 13) Description of Holotype: Shell small, moderately ele- vated, thin but sturdy. Anterior and lateral slopes nearly straight sided, posterior slope convex. Fissure large, + the length of the shell, forward of center, its posterior end at approximately the midpoint, sides of fissure not raised. Radial sculpture lacking except for minute striae visible under magnification; concentric sculpture of thin, raised growth lamellae. Surface translucent pink, with fine white flecking and broad lateral bands of tan. Margin smooth, rounded, slightly thickened but not offset on the inner side, a narrow muscle impression area borders the margin on the lateral and posterior sides. Internal callus around fissure narrow, rounded, separated from the interior by a distinct suture. Length, 11.2 mm, width, 6.7 mm, height, 2.7mm (holotype). : Radula (Text figure 1): Rachidian and 3 adjacent lat- erals of nearly the same size with simple cutting edges, 4* lateral lacking cutting edge, 5™ lateral large, bicuspid, marginal teeth numerous, finely serrate at tips (AHF 132-34). Type Material: Holotype, LACM-AHF 1315 (intact animal preserved separately). Vol. 12; No. 3 THE VELIGER Page 367 Figure 1 Radula of Leurolepas roseola McLEan, spec. nov. Type Locality: Magdalena Island, Tres Marias Islands, Mexico, 21°25’40” N, 106°21’10” W, 13 fathoms, Velero III station 970-39, 9 May, 1939, 1 specimen. Referred Material: SU 50755, Espiritu Santo Island, Gulf of California, 14-25 fathoms, 3 specimens; CAS 27525, Clarion Island, Revillagigedo Islands, Mexico, 1 specimen; LACM A375, Clarion Island, 20 - 40 fath- oms, 1 specimen; AHF 129-34, Socorro Island, Revilla- gigedo Islands, 14-18 fathoms, 3 specimens; AHF 132-34, Socorro Island, 40 fathoms, 1 specimen; US NM _ 567722, Mazatlan, 1 specimen; LACM 65-15, Banderas Bay, Mexico, 1 specimen; LACM 68-41, Barra de Navidad, Jalisco, Mexico, 1 preserved specimen diving at 30 feet; CAS 17832, Port Guatulco, Mexico, 5 specimens; LACM 65-21, Isla Otoque, Panama Bay, 5 - 15 fathoms, 1 specimen; AHF 213-34, La Plata, Ecua- dor, 7 - 10 fathoms, 3 specimens; AHF 221-34, Gorgona Island, Colombia, 20 fathoms, 1 specimen. Discussion: Leurolepas roseola is evidently not uncom- mon throughout the Panamic province on rocky bottoms in relatively shallow sublittoral depths. It is the only eastern Pacific fissurellid lacking radial ribbing and is easily recognized by its large foramen and pink coloration, which its name emphasizes. LITERATURE CITED BERRY, SAMUEL STILLMAN 1964. Notices of new eastern Pacific Mollusca. — VI. Leafl. Malacol. 1 (24): 147 - 154 (29 July 1964) Cowan, Ian McTaccartT 1969. A new species of gastropod (Fissurellidae, Fissurisepta) from the eastern North Pacific Ocean. The Veliger 12 (1) : 24 - 26; 3 text figs. (1 July 1969) FarFANTE, ISABEL PEREZ 1943a. The genera Fissurella, Lucapina, and Lucapinella in the Western Atlantic. Johnsonia 1 (10): 1-20; plts. 1-5 (7 August 1943) 1943b. The genus Diodora in the Western Atlantic. John- sonia 1 (11): 1-20; plts. 1-6 (29 December 1943) 1947. The genera Zeidora, Nesta, Emarginula, Rimula, and Puncturella in the Western Atlantic. Johnsonia 2 (24): 93 - 148; plts 41 - 64 (7 July 1947) KEEN, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus, Stanford, Calif. (Stanford Univ. Press) 1968. | West American mollusk types at the British Museum (Natural History). - IV. Carpenters Mazatlan collection. The Veliger 10 (4): 389-439; plts. 55-59; 171 text figs. (1 April 1968) McLzan, James HamILTON 1966. | West American prosobranch Gastropoda: superfamilies Patellacea, Pleurotomariacea, and Fissurellacea. PhD! thesis, Biology, Stanford Univ., Stanford, Calif. pp. i-x+1- 255; plts. 1-7 Moore, RaymMonp Cecit (editor and director) 1960. ‘Treatise on invertebrate paleontology. Part I (Mollus- ca 1): xiii + 351 pp.; figs. 1 - 216 Opune_er, Nits HyaLmar 1922. Mollusca from Juan Fernandez and Easter Island. pp. 219 - 254; plts. 8,9 In The natural history of Juan Fernan- dez and Easter Island, ed. Carl Skottsberg, vol. 3. Uppsala Pitspry, Henry Aucustus 1890. Manual of conchology. 12: v-xii, 1-323 ;plts. 1-65. Suasky, Donatp R. 1961. | New deep water mollusks from the Gulf of California. The Veliger 4 (1): 18-21; plt. 4, figs. 1-10 (1 July 1961) (June 1966) Page 368 THE VELIGER Vol. 12; No. 3 On Crrnouorsky’s Designation of a Lectotype - for Murex mancinella LINNAEUS BY H. E. VOKES Department of Geology, Tulane University, New Orleans, Louisiana 70118 Member, International Commission on Zoological Nomenclature THE WRITER WAS MUCH DISTURBED to note that Dr. W. O. Cernohorsky (1969, p. 297) had designated as lectotype of Murex mancinella Linnaeus, 1758 a specimen in the Linnaean collection of the Linnean Society of London which, on the basis of all evidence is not part of the original type material and hence is not available for such designation. Under the provisions of the Code of Zoological Nomenclature [Article 74(a) (i) ] CERNOHORS- Ky’s designation is, accordingly, invalid. This, added to the fact that the problem of the identity of the type species of the genus Mancinella Linx, 1807, is presently being considered by the International Commission on Zoologic- al Nomenclature, makes his action peculiarly unfortunate at this time. It has long been known that the Linnaean collection contained three specimens identified as this species. Ac- cording to SmirH (1913, p. 287) “They were mounted upon wooden tablets by Mr. Hanley when he wrote his work I psa Linnaei Conchylia, and two of them are marked in Linné’s handwriting [emphasis mine] with the number 544 of the twelfth edition of the Systema Naturae.”’ These two are the specimens of Drupa cornus R6pine, 1798 that CERNOHORSKY States: “‘are excluded [apparently by him] from the type series; they were either added by Linnaeus after 1758 or were erroneously selected by Hanley as types of Murex mancinella.” It should be noted in passing that Hanley did not select these specimens as types of the species, he simply stated that they were “marked” by Linnaeus as examples of M. mancinella, although it is clear from his introduction to his work (cited later in the present paper) that he considered those specimens marked with the numbers of the tenth edition as representing the Linnaean types of the species described in that edition. It is to be noted, however, that DopcE (1957, p. 136) states that these two specimens are to be taken as syn- types of Murex mancinella, saying: ““The systematists who - follow the current practice of retaining well-known names whenever possible must, in the present case, base their opinion on the presence in the collection of a single undoc- umented specimen of the mancinella of Lamarck and au- thors and thus retain the name mancinella, selecting that specimen out of the syntypic lot as the lectotype of M. mancinella Linné. This is not only a violation of the Rule of Priority, but is the choice of a type unsupported by any evidence whatsoever, except its possible adventitious pre- sence in the tray, and is a disregard of specimens that Linnaeus himself documented as type. I ... see no reason for denying to the specimens of Drupa cornus ROpING their status as syntypes.” This restriction of the type lot to the two specimens “marked” by Linnaeus, if accepted, further serves to in- validate Cernohorsky’s lectotype designation, and at the same time would fix the Linnaean name upon the species now known as Drupa cornus R6pinc, a form that is generically distinct from the species that are today referred to the genus Mancinella Link, to which genus the manci- nella of LAMaRCcK and authors, not of LinnagEus, has long been referred. It was this consideration that led Dr. Keen to request the International Commission on Zoological Nomenclature to declare that the M. mancinella of Lin- NAEUS, 1758, be considered a species dubium and that the type be designated as the M. mancinella of authors. The oldest valid name for the latter appears to be “Vole- ma’ alouina Répine (1798, p. 58; sp. 728) based upon the figure in Martini & CHEMNITZ, Conchylien Cabinet, vol. 3, Tafel 101, figs. 967, 968. The Roding name is older than Purpura gemmulata of Lamarck, 1816, based upon the same illustration, which was listed by Dr. Keen as the valid name (see Bulletin of Zoological Nomenclature, vol. 21, prt. 6, p. 422). The third specimen in the Linnaean collection, which is completely unmarked by Linnaeus, is that which has been selected by Cernohorsky as the lectotype. There is abso- lutely no evidence that it was ever seen by Linnaeus, and in fact, it seems most probable that it was subsequently added during the interval between Linnaeus’ death in 1778 and the time of the Linnean Society’s acquisition of the collection in 1828. Vol. 12; No. 3 THE VELIGER Page 369 It is pertinent to cite the history of the collection as given by DopceE (1959, p. 179): “At the death of Lin- naeus in 1778 his natural history collections, manuscripts and library descended to his son who was himself a com- petent naturalist and who had accumulated a collection of his own. Based upon what we know of his abilities and his conscientious and useful annotations in his own copy of the twelfth edition of the Systema it is probable that the elder Linnaeus’s Collections came to no harm during the time they were in his son’s custody. Certainly there is no evidence that any transfers of specimens were made between the two collections. At the son’s death in 1783, his mother, as his executrix, sold the elder Linnaeus’s Collections and literary material to James Edward Smith of London, then a young medical student. Smith was knighted in 1814. The purchased material arrived in London in 1784, and remained in Smith’s possession until his death in 1828, when it was acquired by The Linnean Society of London of which Sir James Smith was the first President at its foundation in 1788 and re- mained in that office until his death, All of the Linnaean material is still in the possession and custody of the Society. “Smith was primarily a botanist and, as might be ex- pected, was less interested in the zoological portions of the Linnaean Collections. It is admitted that during the many years he held the collections the cabinet of molluscs, at least, was mishandled through the inadvertent replace- ment of specimens in the wrong receptacles as well as by the integration of Smith’s own specimens. Many of the equivocal situations now encountered in connection with the undocumented specimens are the result of these un- fortunate accessions ... .” With respect to the mishandling of the collection while in the possession of Sir James Smith, HANLEy states (1855, p. 2): “Had the cabinet ... passed direct from the hands of Linnaeus to the Museum of the Linnean Society, ... , without any intermediate possession by a third party, the sole additions to the typical examples coeval with the date of his publications would have been those he had acquired subsequently to the appearance of the last edi- ion of his ‘Systema;’ and as these were almost invariably found packed in separate papers or pill-boxes (often in- deed indicated as undescribed), and not distributed like the original types, in metallic receptacles, their presence would have caused but little impediment to any deter- mined search. The collection, however, did not reach the Society direct, but was held for a while by the noted bot- anist Sir James Smith, during whose custody numerous other specimens were mingled with the ancient ones. This ill-advised admixture has not merely augmented to an - almost inconceivable degree the difficulties of investiga- tion, but has too frequently been fatal to any accurate decision.”” HaNLEy also adds (p. 3) “The original speci- mens, when large enough to permit it, had been inscribed by Linnaeus either with their names or with numerals cor- responding to their position in his ‘Systema;’ the smaller ones had been deposited in tin boxes, marked in like manner; oftentimes, indeed the numerals were written on both shell and boxes.” Thus all authors (HANLEY, SmitH, DopcE) who have worked carefully with the Linnaean collection agree that the original Linnean specimens were marked by Linnaeus. In the present case the only specimens thus recognized were the two examples of Drupa cornus Répinc; the third specimen, unmarked, was thus either added sub- sequent to the publication of the twelfth edition or, more probably, by Sir James Smith as a typical example of the “Murex” mancinella of Lamarck and other authors a- mong his contemporaries, It may be significant that the number on the two marked specimens in question is that of the position of the species in the twelfth edition, although the species itself was described, under the number 469, in the tenth edition. According to Haney (p. 3), “It is worthy of remark, that these numerals more frequently correspond to the series of the tenth than of the twelfth edition, a fair ground for believing that these shells were not merely his erroneous after-impressions of his own species, but were admitted and recognized types when the final edi- tion was printed.” Dopcr (1952, p. 8) more specifically states that: “Where the number is of the tenth edition it indicates that the specimen was a recognized and accepted type when the twelfth edition was published.” The fact that the number on the specimens of Murex mancinella is that of the twelfth edition is grounds for the suggestion that Linnaeus did not himself possess a speci- men of this species at the time of the original description in the tenth. It is known that some species which Linnaeus did not himself possess were described from specimens borrowed from the collections of Spengler, Count Tessin, De Geer, Gyllenborg, and others (Dopce, 1959, p. 173), and it may well be that the true “type specimen” of M. mancinella was from one of these other sources. The original description of Murex mancinella in the tenth edition (1758, p. 751) is as follows: “M. testa ecau- data ovata spinis obsoletis, apertura edentula, columella transversim striata.” While CerNonHorsky correctly points out that the spe- cimens of Drupa cornus do not agree with this description in that the aperture is not edentulous but is marked by “5 - 6 prominent labial denticles”, he fails to note that the M. mancinella of LAMaRcK and subsequent authors also does not agree with the description for the columella is smooth, not transversely striated, and the phrase “spinis Page 370 obsoletis” does not conform to the sharp and prominent spines seen in that shell. The first of these differences was noted by HANLey (1855, pp. 295 - 296) and commented upon in some detail by SmMrru (1913, p. 287) in the paper cited by CerNoHorsky. SMITH stated: “The Purpura mancinella of authors does not agree with Linné’s descrip- tion in the tenth edition of the Systema, for the columella is not ‘transversim striata’, and nothing, moreover, is said as regards colour. The ‘apertura edentula’ is fairly descriptive, for the red thread-like lines within the mouth could hardly be termed teeth, yet one would expect such a conspicuous feature to have been referred to if Linné had the shell before him at the time.” The latter italics are those of SmitH, who clearly did not believe that the third, unmarked specimen was a part of the original Lin- nean collection. Smiru also noted, as did HANLEy, that the Murex mancinella of the Museum Ulricae of Linnae- us, published in 1764, is “certainly, in part, the mancinel- la auctorum, for this is shown by the ‘spinae brevissimae purpurascentes’, which is a characteristic feature of that species. The ‘fauce lutea, transversim striata’ [throat saff- ron-yellow, transversely striated] also seems to indicate this species” (SmiTH, 1913, p. 287). The fact that Linnaeus returned to the original tenth edition description of Murex mancinella in the twelfth edition of the Systema without any additions or altera- tions based upon the specimens in the Museum Ulricae which he had studied in the interim, coupled with his acceptance of the specimens of Drupa cornus as repre- senting his species seems to the writer to be rather com- pelling evidence that his concept was of a broad and variable form that probably would include a majority of the presently known species of Thaidinae, and hence, as originally suggested by Smrru, the species should be considered as a species dubium, an action that has been requested of the International Commission by Miss Keen. To summarize: The writer is of the opinion that all available evidence strongly suggests (1) that none of the specimens in the Linnaean collection can properly be taken as representing the types of the Murex mancinella Linnaeus, 1758, the two “marked” specimens bearing the number of the species in the twelfth edition probably having been added to his collection subsequent to 1758, as suggested by CerNoHorRSKy, and the third unmarked specimen probably having been inserted by Sir James Smith in the interval between 1784 and 1828. Hence THE VELIGER Vol. 12; No. 3 neither the DopcE (1957) designation of the two marked specimens as “syntypes” nor the CeRNoHoRSKY (1969) designation of the third, unmarked one as the “lectotype” can be considered as valid actions under the Code. (2) Neither the Murex mancinella of authors nor the “marked” specimens of Drupa cornus fit the original de- scription, which, on the other hand, is too inadequate to permit its restriction to any of the known species of Thai- dinae and the name Murex mancinella of LINNAEUS, 1758, should be considered a nomen dubium. (3) The correct name for the M. mancinella of Lamarck, 1822, and subsequent authors must be taken as Mancinella alouina (RO6pinc, 1798). LITERATURE CITED CERNOHORSKY, WALTER OLIVER 1969. The Muricidae of Fiji — Part II. Subfamily Thaidinae. The Veliger 11 (4): 293-315; plts. 47-49; 21 text figs.; 1 map (1 April 1969) Dopce, HENRY 1952. _A historical review of the mollusks of Linnaeus. Part 1. The classes Loricata and Pelecypoda. Bull. Americ. Mus. Nat. Hist. 100: 1 - 263 1957. _ A historical review of the mollusks of Linnaeus. Part 5. The genus Murex of the class Gastropoda. _ Bull. Amer. Mus. Nat. Hist. 113 (2): 77 - 224 (30 September 1957) 1959. _ Evidential factors in the identification of the Linnaean molluscs. Journ. Linn. Soc. London, Zoology 44 (296) : 170 - 179 (April 1959) HANLEy, SYLVANUS 1855. Ipsa Linnaei Conchylia; the shells of Linnaeus, deter- mined from his manuscripts and collections. London, 556 pp.; 6 plts. LINNAEus, CAROLUS 1758. Systema naturae per regna tria naturae ... editio decima, reformata 1 [Regnum animale]. Stockholm (Laurentii Salvii) pp. 1 - 824+1- iii 1767. | Systema naturae per regna tria naturae ... editio duodecima, reformata 1 [Regnum animale] (2): 533 - 1327. Stockholm (Laurentii Salvii) Ropinc, PETER FRIEDRICH 1798. Museum Boltenianum sive catalogus cimeliorum pars secunda continens Conchylia Hamburg, viii+ 199 pp. (10 September 1798) SmirH, Epcar ALBERT 1913. Note on Murex mancinella Linn. Proc. Malacol. Soc. London 10 (4): 287 - 289 (28 March 1913) Vol. 12; No. 3 THE VELIGER Page 371 A List of Recommended Nomenclatural Changes for MAcFARLAND’S “Studies of Opisthobranchiate Mollusks of the Pacific Coast of North America’’ BY RICHARD A. ROLLER 1127 Seaward Street, San Luis Obispo, California 93401 MANY WORKERS IN THE FIELD of opisthobranchiate mol- lusks have felt the need for a review of the nomenclature of the species treated in MacFarLanp’s posthumously published monograph. Because of restrictions relating to the MacFarland estate, the editors were prevented from making changes at the time of publication by the Califor- nia Academy of Sciences, and the monograph was pub- lished using MacFar.anp’s original names. Some of this needed work has been done already in various publications (see: STEINBERG, 1961, 1963; Opx- cus, 1967; Burn, 1968; SpHon «& Lance, 1968; and Rotter, 1969). The present list, prepared at the sugges- tion of the Department of Invertebrate Zoology of the California Academy of Sciences, brings together all of the recommended nomenclatural changes, old and new. The animals treated in the following list are in the order of their appearance in the monograph. The names used by MacFar.anp appear in the left column (those pro- posed as new in the monograph without author), while the recommended name changes are presented in the right NER, 1963; Lance, 1966; Franz, 1967; Marcus « Mar- MacFartanp Names Aglaja diomedea (plate 2, figure 4) Aclesia rickettsi Il I Hermaea ornata (BErcH) Phyllobranchopsis enteromorphea [sic] CocKERELL & Extot, 1905 Elysia bedeckta Pleurobranchus californicus DALL Acanthodoris columbina MacF ar anb, 1926 Corambella bolini Glossodoris macfarlandi (CocKERELL) Chromodoris californiensis BERGH Chromodoris porterae COCKERELL Austrodoris odhneri Petelodoris spongicola Dendrodoris fulua (MacFaruanp, 1905) column. New Names Aglaja ocelligera (BERGH, 1894) Stylocheilus longicauda (Quoy & Gatmarp, 1824) (see BEEMAN, 1968) Placida dentritica (ALDER & Hancock, 1843) (see Lone, 1969 Hermaeina smitht Marcus, 1961 Elysia hedgpethi Marcus, 1961 (s.SpHON & LANcE, 1968) Berthella californica (Dati, 1900) (see Lance, 1966) Acanthodoris nanaimoensis O’DonocHuE, 1921 (see STEINBERG, 1963) Doridella steinbergae (LANCE, 1962) (see FRANz, 1967) Chromodoris macfarlandi CockERELL, 1902 Hypselodoris californiensis (BERGH, 1879) Hypselodoris porterae (CocKERELL, 1902) Archidoris odhneri (MacFar.anp, 1966) (s. Burn, 1968) Atagema quadrimaculata CoLuiER, 1963 Doriopsilla albopunctata (Cooper, 1863) (see STEINBERG, 1961) Page 372 Dendrodoris albopunctata (CoorER) Duvaucelia tetraquetra (PALLAS) Duvaucelia festiva (STEARNS) ll Il Duvaucelia exsulans (BERGH) Duvaucelia gilberti | Dendronotus venustus Doto varians (C. group of dark- colored specimens) Antiopella aureocincta Coryphella fisher Eubranchus occidentalis Cuthona rosea Wl ll Cratena rutila Cratena flavovulta Cratena fulgens Cratena albocrusta Cratena virens Cratena abronia = Cratena spadix Phidiana nigra Aeolidiella oliviae In treating Aglaja, MacFarLanp described several lots of specimens. Most of these appear to be assigned to the correct species, A. diomedea (Brercu, 1894), according to the shell figures shown (plt. 6, fig. 8; plt. 7, figs. 11-14). However, a specimen received by him from M. W. Willi- ams in 1950 (described on pp. 8-9) was incorrectly as- signed to A. diomedea. The caudal lobes of that specimen were described as having “The left lobe, triangular, of about the same size as the right one but is prolonged far beyond it as a delicate filament (flagellum) ... The filament is 2.5 to 3mm in length, extending beyond the posterior foot margin.” No description of the shell was given. MacFar.anb states that “The specimen matched the colored figure (pl. 2, fig. 4) of the original specimen _ taken from Monterey Bay-in 1894.” The plate descrip- tion on page 396 describes the animal as having the left caudal lobe lengthened into a slender flagellum, and the colored figure on plate 2 shows this flagellum clearly. THE VELIGER Vol. 12; No. 3 Doriopsilla albopunctata (Coorrr, 1863) Tochuina tetraquetra (Pautas, 1788) (s. ODHNER, 1963) Tritonia festiva (STEARNS, 1873) (s. Marcus & Marcus, 1967) Tritonia exsulans BercH, 1894 (see Marcus & Marcus, 1967) Tritonia gilberti (MacFarLanp, 1966) (see Marcus & Marcus, 1967) Dendronotus frondosus (AscANIuS, 1744) Doto kya Marcus, 1961 Antiopella barbarensis (Cooper, 1863) Lance, 1968) Coryphella trilineata O’DoNocHUE, 1921 Capellinia rustya Marcus, 1961 Precuthona divae Marcus, 1961 (see SPHON & LANCE, (see SPHON & 1968) Trinchesia lagunae (O’DonocHuE, 1926) (see ROLLER, 1969) Trinchesia flavovulta (MacFartanp, 1966) (see ROLLER, 1969) Trinchesia fulgens (MacFartanp, 1966) (see ROLLER, 1969) Trinchesia albocrusta (MacFar.anp, 1966) (see ROLLER, 1969) Trinchesia virens (MacFartanp, 1966) (see ROLLER, 1969) Trinchesia abronia (MacFar.anpD, 1966) (see ROLLER, 1969) Catriona alpha (Basa & Hamartant, 1963) (see ROLLER, 1969) Phidiana pugnax Lance, 1961 (s. SpHoN & Lance, 1968) Spurilla oliviae (MacFartanp, 1966)( s. SPHON & LANCE, 1968) BERGH (op. cit., pp. 211, 213) described Aglaja diome- dea as having the left lobe without flagellum; and A. ocelligera as having the left lobe extended intoa 1 mm long flagellum. The text description of the Williams specimen and the plate description and figure of the 1894 Monte- rey specimen indicate a flagellum. Therefore these 2 spe- cimens should have been identified as Aglaja ocelligera (Bercu, 1894). The naming of a new subspecies, Pleurobranchus cali- fornicus denticulatus by MacFaruanp presents a difficult nomenclatural problem. Lance (1966) transferred Pleu- robranchus californicus Dati, 1900 to Berthella califor- nica (Dax, 1900) on the basis of the modern separation of the genera of the family Pleurobranchidae according to the configuration of the gill rhachis. In Berthella BLaIn- VILLE, 1825, the gill rhachis is smooth; while in Pleuro- branchus Cuvier, 1805, the gill rhachis bears a series of tubercles at the junction of the gill plumules with the Vol. 12; No. 3 THE VELIGER Page 373 rhachis. If Datt’s original description of the species “The gill short, its stem finely granular, not tuberculate ...” is accurate, then BercH’s (1902) anatomical account of the same specimen, wherein he states “... the plume made up of alternating tubules at the base of the pinnules, owing to the dilation of the branchial veinules as they join the branchial vein ...,” is somewhat contradictory. If, in fact, DALL’s species has a smooth gill rhachis, then it most properly belongs in Berthella, as suggested by LANCE (op. cit.). However, since the gill rhachis of P californicus denticulatus is described as tuberculate, MAcFARLAND’s species must be placed in Pleurobranchus, and cannot re- main a subspecies. The proper status of Pleurobranchus californicus denti- culatus depends upon a better understanding of the ana- tomy of P californicus s.s. Further study of live material from the type localities of both taxa will be required be- fore this problem can be satisfactorily solved. MacFar.anp also named another pleurobranchid in his monograph, Pleurobranchus strongi. This species was described as having the “ rachis smooth, without tubercles ... ,” and on this basis should be placed in Berthella. However, he also observed a pedal gland and a prostate gland in his material of P strongi; and these characteristics should not be present in members of the genus Berthella, according to BurN’s synoptic key to the Pleurobranchacea (1962). Macnae (1962) does not con- sider these characteristics to be of value for generic sep- aration. The proper generic placement of this species is dependent upon further study of live material from the type locality and a much needed revision of the family Pleurobranchidae. Another nomenclatural problem exists due to the naming of Doto varians. MAcFaRLAND stated that of the many specimens collected by him over a period of years, “An effort has been made to isolate these into groups based largely upon coloration. Three distinct groups are recorded.” He listed the three groups as: A. The speci- mens of lightest colorings; B. The yellow specimens; and C. Group of dark-colored specimens, and stated that “Intermediate forms between the light and dark varieties of coloration are rare, and a complete graduation has never been found.” OpHNER (1936), in his discussion of the nomenclature of the genus Doto OxEN, 1815, stated that “The classifi- cation of the about 20 species which prove valid, offers great difficulties, since only slight differences exist and these are above all to be found in the colouration, ... A classification of Doto must base upon this character, at least for the present.” He rejected as useful character- istics for species separation the use of radular teeth and gills on the inside of the cerata. Marcus (1961) named 4 species of Doto from the Monterey Bay area, namely D. amyra, D. ganda, D. kya, and D. wara. Of these species, only D. kya has any dark pigment mentioned, while the 3 remaining species are all described as light-colored. The group of Doto specimens which MacFar.Lanp de- scribed as “dark-colored” and figured on plate 42 (figures 2, 4, 8) are similar in coloration to D. kya, and should be considered as belonging to that species. However, the “lightest coloring” and “yellow” specimens of MAcFar- LAND are not well enough described to allow allocating them to any of the 3 light-colored species of Marcus (1961). There is much work needed to be done on the members of this: genus before this species (D. varians) can be properly named. There is a typographical error on page 51 in the de- scription of Elysia bedeckta. In the last paragraph on that page, the second sentence states that “The cusp has a length from its anterior basal projection to the tip, of 0.33 mm ...” This figure should be 0.033 mm, according to the original descriptive notes of MacFarland. I wish to thank Mr. Allyn G. Smith, of the California Academy of Sciences, for suggestions and critical com- ments made during the preparation of the manuscript. LITERATURE CITED BEEMAN, RosBErRT Davip 1968. Order Anaspidea. prt. 2) :87- 102; plt. 11; 12 text figs. Bercy, Lupwic SopHus RupoLtpH 1894. Reports on the dredging operations off the west coast of central America to the Galapagos, to the west coast of Mexico and in the Gulf of California, in charge of Alexander Agassiz, carried on by the U. S. Fish Commission steamer “Alba- tross’, during 1891. XIII. Die Opisthobranchien. _—_ Bull. Mus. Comp. Zool., Harvard Univ. 25 (10): 125 - 233; plts. 1-12 (October 1894) 1902. Malakologische Untersuchungen in Semper’s Rei- sen im Archipel der Philippinen. Vol. 7, Abt. 4, Abs. 4: 313 - 382; plts. 25 - 29. The Veliger 3 (Supplement, (1 May 1968) {not seen} 1904. | Nudibranchiata, Tectibranchiata-Pectibranchiata. In: Semper, Reisen im Archipel der Philippinen. 9 (6), Lief. 1: 1-55; plts. 1-4 {not seen} Burn, RoBERT 1962. On the new pleurobranch subfamily Berthellinae (Mol- lusca: Gastropoda) ; a revision and new classification of the species of New South Wales and Victoria. Mem. Nat. Mus. Melbourne, no. 25: 129-148; plts. 1, 2; figs. 1-5 (1 May 1962) 1968. Archidoris odhneri (MacFartanp, 1966) comb. nov., with some comments on the species of the genus on the Pacific Coast of North America. The Veliger 11 (2): 90 - 92 (1 October 1968) Page 374 THE VELIGER Dati, Witt1amM HEALey 1900. A new species of Pleurobranchus from California. Nautilus 14 (11): 125-126 Franz, Davp R. 1967. On the taxonomy and biology of the dorid nudibranch Doridella obscura. The Nautilus 80 (3): 73-79; 1 fig. Lance, JAMES ROBERT 1966. New distributional records of some northeastern Pacific Opisthobranchiata (Mollusca: Gastropoda) with descriptions of two new species. The Veliger 9(1): 69-81; 12 figs. (1 July 1966) Lone, STEVEN J. 1969. Records of Trinchesia virens, Trinchesia fulgens, and Placida dentritica from San Luis Obispo County, California. The Tabulata 2 (4): 9-12; 2 figs. (1 October 1969) MacFaruanp, Frank Mace 1966. Studies of opisthobranchiate mollusks of the Pacific Coast of North America. Mem. Calif. Acad. Sci. 6: xvi + 546 pp.; 72 plts. (8 April 1966) Macnag, WILLIAM 1962. Notaspidean opisthobranchiate molluscs from South Afri- cas Ann. Natal Mus. 15 (15): 167-181; 7 figs. Marcus, ERNST 1961. | Opisthobranch mollusks from California. The Veli- ger 3 (Supplement, pt. 1): 1-85; plts. 1 - 10. (1 February 1961) Marcus, EvELINE & ERNsT Marcus 1967. American opisthobranch mollusks. Studies in tropical Oceanography no. 6. Inst. Marine Sci., Univ. Miami, Florida; viiit+ 256 pp.; 1 plt.; 155+495 text figs. | (December) Opune_rR, Nits HyjALMar 1936. | Nudibranchia Dendronotacea. A revision of the System. Mélanges Paul Pelseneer. Mém. Mus. Roy. d’Hist. Nat. de Belgique, Ser. II, Fasc. 3: 1057-1128; 1 plt.; text figs. 1-47. 1963. On the taxonomy of the family Tritoniidae (Mollusca: Opisthobranchia). The Veliger 6 (1): 48-52 (1 July ’63) Ro ier, RicHarp A. 1969. | Nomenclatural changes for the new species assigned to Cratena by MacFartanp (1966). The Veliger 11 (4): 421-423; 2 figs. (1 April 1969) Rotier, RicHArD A. & STEVEN J. Lone 1969. An annotated list of opisthobranchs from San Luis Obis- po County, California. The Veliger 11 (4) : 424-430; 1 map (1 April 1969) SPHON, Gate G., Jr., x JAMES RoBerT LANCE 1968. An annotated list of nudibranchs and their allies from Santa Barbara County, California. Proc. Calif. Acad. Sci. (4) 36 (3): 73-84; 1 fig. (25 September 1968) STEINBERG, JOAN EMILY 1961. Notes on the opisthobranchs of the west coast of North America. — I. Nomenclatural changes in the order Nudi- branchia (Southern California). | The Veliger 4 (2) : 57 - 63. (1 October 1961) 1963. Notes on the opisthobranchs of the west coast of North America. III. Further nomenclatural changes in the order Nudibranchia. The Veliger 6 (2): 63-67 (1 Oct. 1963) Vol. 12; No. 3 Vol. 12; No. 3 NOTES & NEWS Range Extensions for Acanthodoris hudson’ MACFARLAND, 1905, and Onchidoris bilamellata (LINNAEUS, 1767) BY GARY R. McDONALD 310 Graves Street, San Luis Obispo, California 93401 On May 31, 1969, a single specimen of Acanthodoris hudsoni MacFarxanp, 1905 which measured 11 mm in length and 84 mm in width was collected by Mr. Hans Bertsch from the boat docks at Morro Bay, California. On June 3, 1969, a second specimen, measuring 24 mm in length and 9 mm in width was collected by the author in the low tide zone just south of Spooner’s Cove, Montana de Oro State Park, San Luis Obispo County, California. On July 11, 1969, a third specimen (16 mm long, 11 mm wide) was collected from a depth of 20 feet at Shell Beach, also in San Luis Obispo County. To the author’s knowledge these are the first recorded collections of this species south of Monterey Bay, California, a range ex- tension of about 125 miles. On May 16, 1969, a single specimen of Onchidoris bi- lamellata (Linnagus, 1767), measuring 9 mm in length, was collected by the author from the boat docks at Morro Bay, California. On June 26, 1969, 4 more specimens which measured 20, 20, 22, and 25 mm in length were collected from buoy no. 7 in Morro Bay. On July 24, 1969, 2 more specimens (11 mm and 16 mm long) were collec- ted from a depth of 20 feet in Morro Bay. To the author’s knowledge these are the first recorded collections of this species south of Monterey Bay, California, a range ex- tension of 110 miles. All identifications were made or verified or both by Mr. Richard A. Roller of San Luis Obispo, California. REFERENCES CONSULTED Lance, JAMES ROBERT 1961. A distributional list of Southern California Opistho- branchs. The Veliger 4 (2): 64-69 (1 October 1961) THE VELIGER Page 375 MacFar.anb, Frank Mace 1905. A preliminary account of the Dorididae of Monterey Bay, California. Proc. Biol. Soc. Washington, 18: 35 - 54 Marcus, Ernst 1961. | Opisthobranch mollusks from California. The Veliger 3 (Supplement, pt. I): 1-85; plts. 1-10. (Feb. 1, 1961) Rotter, RicHarp A. & STEVEN J. Lone 1969. An annotated list of opisthobranchs from San Luis Obis- po County, California. The Veliger 11 (4): 424-430; 1 map (1 April 1969) SpHon, Gate G., Jr., « JamES RoBERT LANCE 1968. An annotated list of nudibranchs and their allies from Santa Barbara County, California. Proc. Calif: Acad. Sci. (4) 36 (3): 73-84; 1 fig. (25 September 1968) STEINBERG, JoAN EmILy 1963. Notes on the opisthobranchs of the West Coast of North America - IV. A distributional list of opisthobranchs from Point Conception to Vancouver Island. The Veliger 6 (2): 68 to 73 (1 October 1963) Spawning Notes V. Acanthina angelica 1. OLDROYD, 1918 and Acanthina lugubris (SOWERBY, 1821) BY FAY HENRY WOLFSON Associate Curator of Marine Invertebrates San Diego Natural History Museum, San Diego California 92112 (6 Text figures) FROM MID-WINTER THROUGH late spring, the egg capsules of Acanthina angelica 1. OtpRoyp, 1918 are frequently found in the high intertidal zone throughout the northem Gulf of California. I have observed the spawning process at Bahia de los Angeles from January through April in 1968 and 1969, at Puerto Refugio in Isla Angel de la Guarda in December 1967, and on Isla Cardonosa in April 1969. Fresh capsules were seen by Carol Skoglund (personal communication) at Cholla Bay in March and April 1969 and by me at Bahia San Luis Gonzaga in May 1968. In January 1969, I collected a cluster of capsules and two spawning females at Playa Alicia, south of San Felipe. Page 376 THE VELIGER Vol. 12; No. 3 Table 1 Acanthina angelica Acanthina lugubris Capsule Average maximum dimensions 6.66 X 2.49 mm 8.64 X 3.94 mm Color (relative) Pale yellow Bright yellow Relative thickness of walls Thin Thick Stalk Cylindrical Flattened cylinder Eggs Average number per capsule more than 200 less than 200 Average diameter 119 p 157 p Position of egg mass! Above the stalk at base of capsule, occu- Loosely filling entire length of capsule, but pying up to 4 of the interior space not touching the inner capsule walls Egg mass! Enclosed in a thin, transparent membrane, The eggs form 2 or more irregular columns, attached in one or more areas to capsule each column several eggs deep at the cen- walls ter. The underlying eggs are embedded in a spongy matrix, which also forms a flat sheet separating the columns. This sheet appears to consist of a single layer of cells which resemble flattened eggs. The whole mass lies free within the capsule 1 see schematic section Figure 3 Acanthina lugubris (SowERBy, 1821) Schematic section through an egg capsule Figure 1 Acanthina lugubris (SowERBy, 1821) Egg cluster. Line indicates where section was made for Figure 3 5mm Figure 2 Figure 4 Acanthina lugubris (SowErsy, 1821) Acanthina angelica 1. OtpRoyp, 1918 A single egg capsule seen from the top Egg cluster. Line indicates where section was made for Figure 6 The capsules present an interesting comparison with 1821). One of these is with SDNHM lot no. 22722, col- two clusters of the spawn of Acanthina lugubris (SowErRBy, lected by Henry Hemphill on Isla Cedros and presented to Vol. 12; No. 3 the museum by Herbert Lowe. The other is a cluster which I collected on 12 March 1968 on the westernmost island of the San Benito trio. Figure 5 Acanthina angelica I. OtpRoyp, 1918 A single egg capsule seen from the top Figure 6 Acanthina angelica I. OtpRoyp, 1918 Schematic section through an egg capsule The Acanthina lugubris capsules I collected were being deposited by 2 females in a crevice of a rocky cliff, high above the low-tide line. In contrast, A. angelica typically spawns on the undersides of rocks in groups of a dozen or more individuals. Both the Gulf and coastal capsules are of the characteristic muricid vase type, cemented to the substrate by a fused basal membrane. Other compara- tive data are presented in Table 1. The drawings are by Anne Acevedo of the SDNHM. ERRATA The figures on Plate 27 of our October issue were, through an error, numbered wrongly. Instead of Figures 8 to 13, the numbers should be Figures 1 to 6. We apologize. The Editor. ABOUT SUPPLEMENTS Many of our members desire to receive all supplements published by the Society. Since heretofore we have sent _ supplements only on separate order, some members have missed the chance of obtaining their copies through over- THE VELIGER Page 377 sight or because of absence from home. It has been sug- gested to us that we should accept “standing orders” from individuals to include all supplements published in the future. After careful consideration we have agreed to the proposal. We will accept written requests from individuals to place their names on our list to receive all future sup- plements upon publication; we will enclose our invoice at the same time. The members’ only obligation will be to pay promptly upon receipt of the invoice. Requests to be placed on this special mailing list should be sent to the Manager, Mrs. Jean M. Cate, 12719 San Vicente Boulevard, Los Angeles, California 90049. THE CauirorniA MAtacozootocicat Society, Inc. announces Backnumbers of THE VELIGER and other publications Volumes 1 through 8: out of print {We are pleased to announce that we have completed arrangements with Kraus Reprint Co. to reprint those of our publications that are out of print. Inquiries regarding the availability and price(s) of desired items should be addressed to: Kraus Reprint Co. 16 East 46" Street, New York, N. Y. 10017 We shall publish in this place additional information as it becomes available. } Volume 9: $22.- Volume 10: $24.- Volume 11: $24.- Supplement to Volume 3: $6.-* plus $-.50 handling charge [Part 1: Opisthobranch Mollusks of California by Prof. Ernst Marcus; Part 2: The Anaspidea of California by Prof.. R. Beeman and The Thecosomata and Gymnosomata of the Cali- fornia Current by Prof. John A. McGowan] [The two parts are available separately at $3.- each plus a handling charge of $-.40 or as indicated above. If purchased separately, each part is subject to the Califor- nia State sales tax if mailed to California addresses. ] Supplement to Volume 7: $2.-* plus $-.40 handling charge [Glossary of A Thousand-and-One Terms used in Conchology, compiled by Wintrrep H. ArNnoxp] Page 378 Supplement to Volume 11: $5.-* plus $-.40 handling charge [The Biology of Acmaea by Prof. D. P. Aszorr et al., ed.] Items marked with * are subject to sales tax in the State of California; residents of that State please add the appropriate amount to their remittances. Prices subject to change without notice. Send orders with remittance to: Mrs. Jean M. Cate, Manager, 12719 San Vicente Boule- vard, Los Angeles, Calif. 90049. Please, make checks payable to C. M.S., Inc. Shipments of material ordered are generally made within two weeks after receipt of remittance. Subscription to Volume 12: $18.- domestic; $19.- in Canada, Mexico, Central and South America; $19.50 in all other foreign countries. 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At a Regular Membership meeting of the Society in No- vember 1968 a policy was adopted which, it is hoped, will assist in building up the Endowment Fund of the Society. An issue of the journal will be designated as a Memorial Issue in honor of a person from whose estate the sum of $5000.- or more has been paid to the Veliger Endowment Fund. If the bequest is $25 000.- or more, an entire volume will be dedicated to the memory of the decedent. Moving? If your address is changed it will be important to notify us of the new address at least six weeks before the effective date, and not less than six weeks before our regular mailing dates. Because of a number of drastic changes in the regulations affecting second class mailing, there is now a sizeable charge to us on the returned copies as well as for our remailing to the new address. 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Affiliate Membership for the fiscal year July 1, 1970 to June 30, 1971 has been set at $8.-. Postage for members in Canada, Mexico, Central and South America $1.-, for members in any other foreign country $1.50 additional. THE VELIGER Page 379 METHODS & TECHNIQUES A Mechanical Shell Washer BY JACQUELIN N. MILLER Department of Oceanography, University of Hawaii AND CARL L. HUBBS Scripps Institution of Oceanography University of California, San Diego, California MOLLUSCAN MATERIAL Collected from archeological sites typically requires major cleaning before it can be identi- fied to species or analyzed by weight. Frequently the extraneous coating is particularly tenacious, apparently be- cause the charcoal and soil fuse to the shell during heating in midden fires and/or the encrusting caliche becomes firmly cemented to the shells. During the course of studies on the molluscan fauna from ancient archeological sites (MILLER « Husss, MS in preparation) need arose to devise a method more rapid and thorough than the usual hand scrubbing technique for cleaning the rapidly accumulating, voluminous quan- tities of heavily soiled shells. To meet this need, the me- chanical shell washer described below was developed (see Figure 1). Basically, the device is similar to the standard labora- tory rock tumbler or jar mill, with certain modifications to better adapt it to our purposes. The shell containers are polyethylene cylinders 23 & 15cm with removable in- ternal baffles constructed from 4-inch stock sheets of lucite. The snap-on polyethylene lids are kept secure and watertight by turned aluminum caps connected by screw ‘ Contribution from Scripps Institution of Oceanography, Uni- versity of California, San Diego, California 92037 Page 380 THE VELIGER Vol. 12; No. 3 Figure 1 rods and wing nuts. ‘These cylinders, tightly sealed by the GALL, caps, ride freely on two sets of rollers driven by a 1/15 hp. |<—— 15 cm ——>| electric motor. A simple frame of stainless steel rods and laboratory clamps attached to a heavy wooden base keeps the cylinders centered on the rollers (Figure 2). To wash a sample, the cylinders are filled approximately 3 full of shell. Hot water and 6 cc of a non-foaming de- (: if Loreen ff i tergent are added to within 3 cm of the top. For shells =: | heavily encrusted with caliche a few drops of hydrochloric acid may be added. The polyethylene lids are then sealed with the aluminum caps and the cylinders are placed on the rollers to wash for 15 to 45 minutes, depending on the size and condition of the sample. When a sufficient time has elapsed, the cylinders are removed and the sample is rinsed into a 4mm sieve. The soil passing through the sieve is collected in a tray where it is available for further examination. The cleaned shells remaining in the sieve are oven-dried preparatory to sorting for species and analysis by weight. We feel that this particular machine has several ad- vantages over the commercially available models. Use of polyethylene in place of metal or glass cylinders assures virtually no breakage of even the more fragile species. Fewer problems of leakage are encountered with the free-riding cylinders than with direct-drive cylinders. The polyethylene cylinders are much lighter and more easily handled in loading and unloading than comparable sized metal, porcelain, or glass cylinders, and there is no corrosion problem. The entire assembly, complete with cylinders and labor, may be reproduced for about two- thirds the cost of commercially available tumblers. 6 Polyethylene Cylinder R ble Lucite Baffle Ey) yy ertetee c 8 with Baffle inserted i LLL Aluminum Caps Complete Assembly Figure 2 Vol. 12; No. 3 THE VELIGER Page 381 BOOKS, PERIODICALS, PAMPHLETS Superfamilia UNIONACEA by Dr. Fritz Haas, Chicago, Illinois. x-+663 pp., 5 text figs. Part 88 of “Das Tierreich,” publ. Walter de Gruyter & Co. Berlin (in German). 380.- DM (= approximately US$ 105.- at present exchange rates). Dr. Haas has produced an exceedingly thorough sys- tematic study of the pearly fresh-water mussels of the world, which no doubt will serve as a basic reference for many years to come. He is eminently qualified to under- take such an extensive work, having already published on the Bivalvia in Bronn’s well-known “Klassen und Ord- nungen des Tierreichs” covering more than 1900 pages of text. The statistically minded will be interested to learn that the Unionacea is divided into 4 families, broken down into 6 subfamilies, 142 genera, 111 subgenera, and 826 species (the considerable number of subspecies not de- termined for this review). Dr. Haas’ treatment includes several features that the systematist will find very useful. Dichotomous keys to the various subfamily, genus, subgenus, and species groups are provided; type localities as well as geographic ranges are given for each species in addition to brief diagnoses. Syn- onymies are arranged chronologically along with complete original references, making an over-all terminal biblio- graphy unnecessary. Names in synonymy include the orig- inal references only. No one can accuse the author of not being a thorough bibliographer as indicated, for example, by the 526 entries for Anodonta cygnea Linnaeus for the period 1758 to 1945, occupying 21 text pages! There is a good index. According to Haas only 6 species of the Unionacea occur in western North America. These are Margaritifera margaritifera (LINNAEUS, 1758), Gonidea angulata (LEa, 1838), Anodonta (Anodonta) beringiana MippENDORFF, 1851, A. (A.) oregonensis Lea, 1838, A. (Arnoldina) dejec- ta Lewis, 1875, and A. (Brachyanodon) impura Say, 1829. If this arrangement is adopted some name changes will be necessary for certain well-known Pacific Coast species. Anodonta wahlametensis Lea, 1838, A. nuttalliana Lea, 1838, and A. nuttalliana idahoensis HEMPHILL, 1891, are listed as synonyms of A. oregonensis; similarly, A. californiensis Lea, 1852 becomes a synonym of A. impura. The extent to which these taxonomic changes should be accepted is left to specialists in the group. __ The price of the volume, quoted at 380 Mark, is the equivalent of over $100.- at the re-valued exchange rate. This, unfortunately, is far beyond the means of many scientists and scientific libraries and is extremely high for a splendid scientific work that should be readily available to all systematic biologists, especially the malacologists. At current rates of 3 cents for Xerox copies per page, the entire book could be reproduced for $20.19. Thus the unusually high initial cost will no doubt lead to a clandes- tine and frequent violation of the copyright restriction placed on this book. AGS Pleistocene Molluscs from the Namaqualand Coast by A. J. Carrincton &« B. F Kens ey. Ann. South African Mus., Vol. 52, part 9, pp. 189 - 223; plts. 18 - 29; 11 text figs. July 1969. Twenty species of mollusks of Pleistocene age are re- ported and discussed from raised beaches on the Nama- qualand coast of South Africa. Of these, 17 species and subspecies are described for the first time. A new genus, Namamurex, type by M, N. odontostoma, spec. nov. (p. 198; plts. 20, 21), is compared with Acanthina, Cerato- stoma, Pterorytis and Jaton. The shell of this new taxon has 4 or 5 whorls, 3 varices per whorl but no sculpture between the varices. The aperture is longer than the spire. There are about 8 nodules on the inner margin of the outer lip and just below these a prominent tooth. The anterior canal is open. A species of interest to west American workers is Hes- pererato oppenheimeri, spec. nov. (p. 199; plt. 19, fig. C), which is compared with H. vitellina (Hinps, 1844), orig- inally described from Magdalena Bay, Lower California, Mexico. The authors state that the generic affinities of the new species and the geographic ranges of previously recorded species in this assemblage suggest that during early Pleis- tocene time, at least, the water along the adjacent coast was considerably warmer than today. LGH Catalogo de los Moluscos Marinhos del Uruguay by ALFREDO FicuEmRAS & Omar E. Sicarpi. = Communic. Soc. Malacolég. Uruguay, Vol. 2, no. 15, pp. 255 - 275, laminas 1 and 2 (pp. 274 - 275). October 1968. This (the second) part of a catalog of the marine mol- lusks of Uruguay includes 12 species of Scaphopoda and 36 species of Pelecypoda. Geographic distribution only is reported for the Scaphopoda; descriptions, synonymy, Page 382 THE VELIGER Vol. 12; No. 3 comments and geographic distribution are given for the bivalves, and all except 3 are illustrated by line drawings. In addition, a line drawing of a single valve of each of 3 species of Amphineura is included. LGH Systematics, Ecology, and Distribution of the Mollusks of Los Roques, Venezuela Bull. Mar. Sci. (Univ. Miami Sept. 1969. by Ropert C. Work. Press), Vol. 19, no. 3, pp. 614 - 711; 4 figs. One hundred and twenty five species of marine mol- lusks from San Roque, Venezuela, are distributed in 4 Classes: Amphineura (3), Gastropoda (87), Pelecypoda (34), Cephalopoda (1). An historical summary is given, and the zoogeography and ecology are discussed as well as the feeding habits of some of the gastropods. Records of the occurrences of the species are reported and a special effort is made to establish accurate geographic ranges. LGH Contributions to the Knowledge of South African Mollusca. Part VI. Supplement. by K. H. Barnarp. prt. 4, pp. 595 - 661, plts. 1, 2, 30 text figs. Ann. South Afr. Museum, Vol. 47, July, 1969. This posthumous paper by KeppELL Harcourt Bar- NARD was prepared for publication by B. EF Kens.ey. About 156 species and 2 varietal forms are reported and discussed, including notes on many other species. All are gastropods, except 2 pelecypods. Of the total number, 10 forms are identified only as to genus. The radulae of many of the gastropods are described or illustrated. Illustrations include 22 species previously described or mentioned by BaRNARD in earlier parts of a series of papers dealing with the marine mollusks of South Africa. Families especially well represented in the present paper are the Turritidae (34 species, 1 variety, 5 others identified only as to genus) and the Marginellidae (14 species). The following 16 species are described for the first time: Surcula aditus, Drillia dovyalis, D. pecus, D. erepta, Pleurotoma curricula, Persicula nigrocrocea, P. alborubida, Nassa rhysonepia, Trophon beatum, Tritonalia juritzi, T. aedicularum, Fossarus translucens, Scala munda, ?Retro- tortina cuniculus, Turbo boswellae, Calliostoma circus. An extensive bibliography is included. LGH A Monograph of the Cephalopoda of the North Atlantic: The Family Joubiniteuthidae by Ricrarp E. Younc & CiypE F E. Roper. Smithson. Contrib. Zoolog. no. 15: pp. 1 - 10; 6 text figs. U.S. Govt. Printing Off., Washington, D.C. 20402, 25 cents. 1969. In this beautifully illustrated paper the authors syn- onymize Valdemaria danae Jounin, 1931 with Joubini- teuthis portieri (Jounin, 1912) ; they confirm the validity of the family Joubiniteuthidae as established by NaEF in 922% RS An Illustrated Key to the Families of the Order Teuthoidea (Cephalopoda) by Ciype E E. Roper, RicHarp E. Youne & Giipert L. Voss. Smithson. Contrib. Zoolog. no. 13: pp. 1 - 32; 16 text figs. U. S. Govt. Printing Off., Washington, D. C, 20402, 45 cents. 1969. A dichotomous key leads to the 25 families of the order Teuthoidea; illustrations include representatives of each family; and the current state of systematics within each family is discussed briefly. RS The Tertiary Non-Marine Mollusca of South America by Juan J. Paropiz. Ann. Carnegie Mus., vol. 40 etc. This excellent work was discussed in our October issue (vol. 12, p. 236) ; we indicated at that time that we were not able to inform our readers how this work might be acquired. We are delighted to be able to rectify this now: this scholarly work can be obtained by writing to Carnegie Museum, 4400 Forbes Avenue, Pittsburgh, PA 15213 The book is priced at $7.- plus a 25 cent shipping charge. Editor. THE VELIGER is open to original papers pertaining to any problem concerned with mollusks. This is meant to make facilities available for publication of original articles from a wide field of endeavor. Papers dealing with anatomical, cytological, distri- butional, ecological, histological, morphological, physiological, taxonomic, etc., aspects of marine, freshwater or terrestrial mollusks from any region, will be considered. Even topics only indirectly concerned with mollusks may be acceptable. It is the editorial policy to preserve the individualistic writing style of the author; therefore any editorial changes in a manuscript will be submitted to the author for his approval, before going to press. Short articles containing descriptions of new species or other taxa will be given preferential treatment in the speed of publication provided that arrangements have been made by the author for depositing the holotype with a recognized public Museum. Museum numbers of the type specimens must be included in the manuscript. Type localities must be defined as accurately as possible, with geo- graphical longitudes and latitudes added. Short original papers, not exceeding 500 words, may be published in the column “NOTES and NEWS’; in this column will also appear notices of meetings of regional, national and international malacological organizations, such as A.M. U., U. M.E., W.S.M., etc., as well as news items which are deemed of interest to our Members and subscribers in general. Articles on “METHODS and TECH- NIQUES” will be considered for publication in another column, provided that the information is complete and techniques and methods are capable of duplication by anyone carefully following the description given. Such articles should be mainly original and deal with collecting, preparing, maintaining, studying, photographing, etc., of mollusks or other invertebrates. A third column, entitled “INFORMA- TION DESK,” will contain articles dealing with any problem pertaining to collecting, identifying, etc., in short, problems encountered by our readers. In contrast to other contributions, articles in this column do not necessarily contain new and original materials. Questions to the editor, which can be answered in this column, are invited. The column “BOOKS, PERIODICALS, and PAMPHLETS” will attempt to bring reviews of new publications to the attention of our readers. Also, new timely articles may be listed by title only, if this is deemed expedient. Manuscripts should be typed in final form on a high grade white paper, not exceeding 81,” by 11”, at least double spaced and accompanied by a clear carbon or photo copy. A pamphlet with detailed suggestions for preparing manuscripts intended for publication in THE VELIGER is available to authors upon request. A self-addressed envelope, sufficiently large to accommodate the pamphlet (which measures 51,” by 81”’), with double first class postage, should be sent with the request to the Editor. EDITORIAL BOARD Dr. Donatp P. Asgort, Professor of Biology Hopkins Marine Station of Stanford University Dr. Jerry DonouuE, Professor of Chemistry University of Pennsylvania, Philadelphia, and Research Associate in the Allan Hancock Foundation University of Southern California, Los Angeles Dr. J. Wyatr Duruam, Professor of Paleontclogy University of California, Berkeley Dr. E. W. Facer, Professor of Biology Scripps Institution of Oceanography, La Jolla University of California at San Diego Dr. Caner Hanp, Professor of Zoology and Director, Bodega Marine Laboratory University of California, Berkeley Dr. G Datias Hanna, Curator Department of Geology California Academy of Sciences, San Francisco Dr. Jorn W. Hepcretu, Resident Director Marine Science Laboratory, Oregon State University Newport, Oregon Dr. Leo G. HERTLEIN, Curator of Invertebrate Paleontology California Academy of Sciences, San Francisco EDITOR-IN-CHIEF Dr. RupoLF STOHLER, Research Zoologist University of California, Berkeley Dr. A. Myra KEEN, Professor of Paleontology and Curator of Malacology Stanford University, Stanford, California Dr. Victor LoosanorF, Professor of Marine Biology Pacific Marine Station of the University of the Pacific Dr. Joun McGowan, Associate Professor of Oceanography Scripps Institution of Oceanography, La Jolla University of California at San Diego Dr. Franx A. Pirevxa, Professor of Zoology University of California, Berkeley Mr. Attyn G. Situ, Associate Curator Department of Invertebrate Zoology California Academy of Sciences, San Francisco Dr. Ratpu I. Smiru, Professor of Zoology University of California, Berkeley Dr. Cuar.es R. Stasex, Associate Professor of Zoology Florida State University, Tallahassee, Florida Dr. Donatp M. Witson, Professor of Biology Department of Biological Sciences Stanford University, Stanford, California ASSOCIATE EDITOR Mrs. JEAN M. Cate Los Angeles, California A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, INC. Berkeley, California VOLUME 12 April 1, 1970 ConTENTS A Report on the Feeding of Dendronotus iris on the Anthozoan Cerianthus sp. from Monterey Bay, California (Plates 55 to 57) Don R. Wosser . Rarity eh vcvel ob sate anne Cargoa cupella, New Genus and New Species of Nudibranch from Chesapeake Bay and the Generic Status of Okenia MENxKeE, Idalia LEucKarT, and Idalla ORSTED (5 Text figures) RosauizE M. VocEL & Leonarp P ScHULTz . Malacological Applications of Scanning Electron Microscopy. I. Introduction and Shell Surface Features (Plates 58 to 60) ALAN SOLEM ay rey ry Ween aera en The Effect of Wave Impact on some Aspects of the Biology of Sea Mussels (9 Text figures) J. R. E. Harcer . Supplementary Comments on Deep Water Volutidae from the South China Sea and South Africa (Plate 61) Haratp A. REHDER . owe Uptake of Sea Water into the Fluid Spaces of the Prosobranch Gastropod, Acmaea scutum H. H. WEBBER Notes on the Deep Water Calliostomas of the Panamic Province, with Descriptions of Six New Species (Plate 62) James H. McLean . RNS os ls An Annotated Bibliography of References to Marine Mollusca from the Northern State of Sonora, Mexico Caro, SKOGLUND [Continued on Inside Front Cover] - 383 . 388 - 394 - 415 - 417 . 421 EEE Distributed free to Members of the California Malacozoological Society, Inc. Subscriptions (by Volume only) payable in advance to Calif. Malacozool. Soc., Inc. Volume 13: $18.- Domestic; $19.- in the Americas; $19.50 in all other Foreign Countries Single copies this issue $14.-. Postage extra. Send subscription orders to Mrs. JEAN M. Care, 12719 San Vicente Boulevard, Los Angeles, California 90049. Address all other correspondence to Dr. R. STOHLER, Editor, Department of Zoology, University of California, Berkeley, California 94720 Second Class Postage paid at Berkeley, California Contents — Continued The Systematics and Some Aspects of the Ecology of the Genus Dendronotus (Gastropoda : Nudibranchia) (Plates 63 and 64; 28 Text figures) Gorpvon A. RoBILLIARD . Na ee PE CU NLn ee ics cy 0G. |e) aod! - 433 Notes on the Egg Capsules and Larval Development of Conus purpurascens BRODERIP (10 Text figures) James NYBAKKEN 10160225000. Bop.) Ie al ene e ee to oO A Supplement to the Annotated List of Opisthobranchs from San Luis Obispo County, California RIGHARD’ A.) ROLLER of. 7. ss, ese cout on non at om OS NOTES & NEWS... 88) (5 20) cA eee ree 484 Concerning the Validity of the New Species of Paravitrea Proposed by BRANSON & BATCH, 1970. Lanpon T. Ross & LAwRENCE G. ABELE BOOKS, PERIODICALS & PAMPHLETS............. . 487 Xs) we, eee Note: The various taxa above species are indicated by the use of different type styles as shown by the following examples, and by increasing indentation. ORDER, Suborder, DIVISION, Subdivision, SECTION, SUPERFAMILY, FamiLy, Subfamily, Genus, (Subgenus) New Taxa Vol. 12; No. 4 THE VELIGER Page 383 A Report on the Feeding of Dendronotus iris on the Anthozoan Cerianthus sp. from Monterey Bay, California BY DON R. WOBBER San Francisco State College, San Francisco, California (Plates 55 to 57) INTRODUCTION Dendronotus iris Cooprr, 1863, 1s FOUND subtidally throughout the year in Monterey Bay, California, feeding on the anthozoan Cerianthus sp. The association which has evolved between the two animals has not been pre- viously described and might be viewed as a simple preda- tor-prey relationship, were it not for the fact that D. iris crops but does not, or perhaps can not, destroy the Cerianthus. After consuming only a very limited part of this prey, the nudibranch moves to other Cerianthus in- dividuals for further feeding. It is rare in nature to find different species of similar size where this type of “conservation” exists. This and other factors point to a delicate interrelationship which could be said to approach parasitism. The present study is a description of some of the behavioral aspects of this association. METHODS ano MATERIALS Observations and experiments, using SCUBA gear, were made off the seaward side of the United States Coast Guard Breakwater (hereafter referred to as the ‘Break- water’) at the southwest end of Cannery Row, Monterey, California, from 1965 to 1969, at depths of 50 to 60 feet. A rectangular quadrant area of 3m < 33m _ was marked off on the flat mud bottom running parallel to the base of the Breakwater. The protected edge of the study area was bordered by large boulders which form the Breakwater. The study area contained 193 Cerianthus individuals. Notes were kept on this population, which remained stable, from October 5, 1968 to December 31, 1968. Cerianthus grow densely the length of the Break- water, concentrated in a narrow strip close to its base. An equal area directly to the seaward of the study area supported only 11 animals. Cerianthus were isolated on the bottom in cages made of aluminum frame and screening, held in place by alu- minum stakes pounded into the soft substrate. Specimens of Dendronotus iris were of 2 distinct color phases. Most had salmon-red bodies, and cerata and branchial processes with orange ends, the tips of which were white. In others the bodies were much lighter in color, light milky purple with light orange processes, tipped with white. The cerata and branchial processes of both color phases sometimes had smaller purple side branches. The largest specimen was 20cm long. There seemed to be no relationship between color and size. OBSERVATIONS Feeding Dendronotus iris feeds on Cerianthus tentacles. Over a period of 2 months, 2 to 6 nudibranchs were found on each dive in the study area. These were generally in various attitudes of feeding. Because the average Ceri- anthus tube projects above the substrate about 15cm (larger specimens to 21 cm), the nudibranch must climb the tube to reach the tentacles. Two methods of feeding were recorded. The first approach is used mainly by smaller (5 cm or less) Dendronotus iris. The nudibranch climbs the tube and slowly enters the rim of marginal tentacles. At this point Cerianthus reacts by: a. retracting swiftly and directly down its tube, D. iris often climbing into the tube after the tentacles, or b. allowing the nudibranch to crawl in among its partially withdrawn tentacles and feed (Plate 55, Figure 1), or Page 384 c. curling the ends of its marginal tentacles into tightly coiled “pigtails,” in which case the nudibranch crawls back down the outside of the tube and leaves. This is uncommon and has only been seen twice (Plate 57, Figures 5 and 6). The second approach, in which the nudibranch is pulled into the Cerianthus tube, is common among larger nudibranchs. The nudibranch crawls up the outside of the tube to within 35 mm of the lip. When one of its spreading crown papillae, which form branched sheaths surrounding retractile rhinophores, touches a tentacle, an immediate and obvious stimulation of the nudibranch takes place. The nudibranch raises the front part of its body from the surface of the tube, arching the head back as though peering up at the tentacles spread out above. At the same time the mouth is thrust out baring large, fleshy lips, and elongating the otherwise rather thick and snubbed anterior end. Thus extended, the nudibranch makes a sudden upward thrust with the anterior part of its body, almost always catching one or more of the marginal tentacles in its mouth (Plate 55, Figure 2). The lips of D. iris form a vertical groove in which the tentacle is aligned. As well as aligning the tentacle for the jaws to close on, the lips seem to orient the nudi- branch in relation to the position of Cerianthus. Some- times after brief lip contact with the distal end of a tentacle, the strike is made at the tentacle base. Dendro- notus iris then gives a violent tug backwards, causing Cerianthus to retreat quickly into its tube. The nudi- branch hangs onto the tentacles with its jaws. In most instances the force of the retreating tentacle(s) pulls the nudibranch from its hold on the outside of the tube over the lip, head first, down into the interior where it dis- appears completely from sight (Plate 56, Figure 3). The nudibranch stays inside the tube to complete feeding. Time spent inside tubes varied from 20 minutes to over 24 hours. Large Dendronotus iris sometimes miss in the attempt to bite Cerianthus tentacles. The Cerianthus retract and the top of the tube often collapses by folding, or the end pinches closed. If this happens, most D. iris do not, or can not, enter. If the tube remains open, the nudibranch climbs in and feeds. To isolate the effect of Cerianthus tentacles on D. iris, marginal tentacles were cut from live THE VELIGER Vol. 12; No. 4 Cerianthus. Three or 4 of these tentacles were held with a test-tube holder so that the distal ends were free. A D. iris was found crawling across the substrate (not on Cerianthus). Cerata touched by anemone tentacles showed no reaction. The tentacles were touched to the crown papillae. As soon as contact was made, the Dendronotus began extruding the mouth area (as described above) and arched back the head exactly as it does when on a Ceri- anthus tube. It extended its anterior end and made a lunge forward, biting with its jaws as though biting at tentacles. A Dendronotus iris was placed on the tube of a retracted Cerianthus. No tentacles projected from the tube. When the crown papillae of D. iris were touched briefly with the testing tentacles, D. iris reacted exactly as above, this time making lunges toward the top of the tube, striking several times with its jaws. During one observation period 3 Dendronotus iris struck at, but did not successfully hold onto Cerzanthus tentacles. All 3 Cerianthus retracted and the nudibranchs left. Two of the Cerianthus came out again within 2 hours. The third remained within its tube for over 8 hours. None of the 3 had its tentacles damaged by the D. iris encounter. Sightings of such retractions and the re-emergence of Ceri- anthus varied from 1 hour and 20 minutes to over 84 hours. Quiescent Posture Dendronotus iris is sometimes seen in a “sleeping” or quiescent posture. In this posture a nudibranch clings to the outside of a tube near the top, attached by the poste- rior end of its foot. The anterior part of the foot is unattached, and the back is arched. The head is held in an upright position, and the nudibranch does not move, except to sway back and forth with the currents. When taken off the tube in this state, a nudibranch took a few seconds to become active again. One D. iris maintained the quiescent posture for over 8 hours. Whether the quiescent posture represents a digestive period, a recovery period, or otherwise, I cannot say. Some nudibranchs crawl off the Cerianthus immediately after feeding, some remain on the tube to lay eggs, and others assume the quiescent posture. Explanation of Plate 55 Figure 1: Dendronotus iris feeding among extended Ceranthus sp. tentacles. Figure 2: Dendronotus iris on Cerianthus sp. tube. Dendronotus iris has just made a sudden upward thrust, baring large fleshy lips which make contact with a Cerianthus sp. tentacle. Tue VELIGER, Vol. 12, No. 4 [WopBeER] Plate 55 Figure 2 photographs by Don Woszer Vol. 12; No. 4 THE VELIGER Page 385 Escape When Dendronotus iris is handled, it often swims by means of heavy side-to-side gyrations of the body (Plate 56, Figure 4). This motion in light surge conditions, nor- mal off the Breakwater, does not appear to orient the nudibranch in a positive direction, but seems to be an escape response to take it off the substrate. I did not test this swimming reaction in the laboratory or under controlled conditions. AGERsBorG (1922) states that swim- ming is Dendronotus giganteus’ most common mode of locomotion and assumes that it is pelagic in habit (D. giganteus O’DonocHUuE, 1921 is synonymized with D. iris by MAcFartanp, 1966). Dendronotus iris’ swimming activities in Monterey seem restricted to escape reactions only. Once off the bottom, D. iris is at the mercy of water movement until it comes in contact with something solid for a new foothold. The active reef predator, Pycnopodia helianthoides (BranpT, 1835), is often seen on the floor of the bay. This sea star is able to excite Dendronotus iris into a violent type of swimming escape response. In one obser- vation, the anterior end of D. iris was inside the tube of Cerianthus with only the posterior end visible. Pycnopo- dia helianthoides was placed 15cm from the base of Cerianthus. The sea star approached, one ray slowly ex- tending towards the nudibranch. As soon as contact was made, the nudibranch backed out of the Cerianthus tube, released itself from the tube, and started gyrating. Water currents carried it away. Twenty similar experiments with P. helianthoides and different D. iris resulted in the same immediate escape reaction. The bat star, Patiria miniata (BRANDT, 1835), often seen on Cerianthus tubes, will cause a slower and not so violent swimming reaction of shorter duration. I have never seen a sea star of any kind attack Dendronotus iris in the field under natural conditions. It is of interest that when a ray of Pycnopodia helianthoides is touched to the Cerianthus, the sea star withdraws its ray. Dendronotus iris is affected adversely when it comes in contact with the anemone Tealia sp. which is found among the Cerianthus beds. I have guided several swim- ming D. iris onto Tealia. The tentacles immediately ad- here to the D. iris and pull it toward the mouth where it disappears into the gullet. Usually a slight escape response is seen, but the response is weak and ineffective, as though the nudibranch were partially paralyzed. When a single Tealia tentacle was touched to D. iris, the nudibranch turned aside and crawled in the other direction. Reproduction Dendronotus iris lays ringlets of white eggs on the outside of Cerianthus tubes, attaching them at a point high off the muddy bottom. This position may help in avoiding predators, and additional protection may be gained by proximity to the anthozoans’ tentacles. Eggs have been seen during most of the months of the year and at one time adults of all sizes are found. Copulation takes place on the Cerianthus tube or on the mud bottom. Copulation between the two color phases of D. iris is common. Locomotion The expansive foot of Dendronotus iris is elongate, flattened, and muscular. It is highly ciliated and has good adhesive qualities (AGERsBorG, 1922). The foot is adapted for travel on sand or mud bottom, and for clinging to Cerianthus tubes in surge conditions. Movements of crawling Dendronotus iris were traced. Animals were seen to crawl past Cerianthus in what seemed to be random directions. However, when crawling away from Cerianthus beds, nudibranchs were seen to reverse their direction. Whether or not a specific chemical attractant or other signal is involved needs to be explored. Tentacle Damage The foraging habits of Dendronotus iris are such that it goes from one Cerianthus to another. After being at- tacked, the anthozoan stays within its tube. Cerianthus near feeding D. iris are often retracted, as though having been recently disturbed, even though 90 to 95% of the Cerianthus outside the immediate area may be in the expanded state. Repeated examinations of Cerianthus tentacles after D. iris has fed on them, have shown only minor damage with but 2 to 10 tentacles missing. To get an indication of damage a single nudibranch might do to a Cerianthus if both were confined, 2 nudi- branchs over 16cm in length were kept in the field without food for 48 hours. Cylindrical screen cages 48 cm high by 30 cm diameter were placed over separate Ceri- anthus. One “starved” nudibranch was placed in each of the 2 containers. Within 15 minutes, both nudibranchs had climbed the Cerianthus tubes, attacked the tentacles, and were pulled inside the tubes, where they remained. Four days later both nudibranchs were on the bottom of the cages. When the cages were removed the nudibranchs crawled away to feed on other Cerianthus. The 2 test Page 386 THE VELIGER Vol. 12; No. 4 Cerianthus remained retracted. Three days after the cages were removed, only one test Cerianthus was out and feeding. Only 20 to 30 tentacles appeared normal. Others were eaten off at various lengths, more than half left quite long. The top 6 cm of the tube of this Cerianthus was tapered, white and smooth on its outside as though newly secreted. Within one week it had darkened, thick- ened and looked normal. The second Cerianthus was in its tube, which was bent in an arc, and seemed lifeless. Eleven days after the removal of the Dendronotus iris, the first Certanthus tentacles had regenerated back to normal, and the second had finally emerged from its tube, the damage to its tentacles only slight. Tentacle Curling The tight end-curling of the marginal tentacles of Cerz- anthus mentioned earlier has been observed on numerous occasions. The exact function of this reaction is not known. Usually, when disturbed, the tentacles are pulled inside the tube with a single, swift motion. End-curling can be induced artificially by lightly touching some of the ten- tacles. As soon as contact is made all tentacles jerk in unison about halfway in, then quiver and curl into the typical “pigtail” shapes. It is possible that tentacle end-curling is defensive, that coiled tentacles expose a more concentrated mass of nematocysts to predators. Whether a heavier concentra- tion of nematocysts would affect Dendronotus iris is not known. The curling could be a form of retreat, a method of pulling in tentacles so they cover less area. Curling could also be a reaction preparatory to withdrawal. ‘Tentacle end-curling has not previously been described, and may not be a universal trait. Cerzanthus in Baja Cali- fornia, Mexico, will curl the tentacles; however, the anemones’ reflexes are much slower and show no prelim- inary quivering. G. Robilliard reports seeing tentacle end- curling in the Puget Sound area (personal communica- tion). Dr. G. A. Horridge states that he has not observed these curling reactions in the Naples species (personal communication). DISCUSSION THompson (1962) remarks “nudibranchs preying on organisms which form stable, abundant populations in certain types of locality have annual life cycles; usually a single breeding period each year.” A single breeding peri- od coupled with a possible change of diet at maturity would allow sedentary prey a respite from heavy cropping: a period to grow and reproduce before the next mature generation’s onslaught. Dendronotus iris reproduces the year round. Nudi- branchs of all sizes afford no relief to a standing crop of Cerianthus, whose life span may cover a period of 10 to 40 years (Hyman, 1940, p. 632). While large nudi- branchs and a constant harvest are a condition of exist- ence, the continuing harvest of Cerianthus seems well ordered and light, and the subtleties of the predator-prey interrelationships contribute to what appears to be a well balanced and stable ecosystem. Dendronotus iris’ extensive branched crown papillae are sensitive to Cerianthus tentacles. Stimulation of these, regardless of the particular substrate the nudibranch is on or its physical orientation, triggers a chain of predictable responses which culminate in the biting action. The fleshy mouth is well adapted for positioning tentacles and the large prominent jaws for grasping and holding on. Nematocyst cells in the Cerzanthus tentacles keep other predators away. What actual effect they have on Dendro- notus iris is uncertain. The curling response of the ten- tacles and the fact that the tentacles are often curled within the tube when the anemone is retracted are of interest. Quick, complete withdrawal of tentacles might be viewed as a way of escape, often causing the biting D. iris to miss. This, combined with a closing or collapsing tube, serves to frustrate attack. On the other hand, it seems more than a drastic outcome for the anemone to pull the nudibranch into its tube. Once the nudibranch is in the tube, its feeding may be restricted. Perhaps a nematocyst threshold, mucus emission, low oxygen level, the nudibranchs’ limited digestive capacity for Ceran- Explanation of Plate 56 Figure 3: Dendronotus iris in the process of being pulled into the tube of the anthozoan, Cerianthus sp. Figure 4: Dendronotus iris “swims” by means of heavy side to side gyrations of the body. This appears to be an escape reaction. Explanation of Plate 57 Figure 5: Dendronotus iris among Cerianthus sp. tentacles. Note that the tentacles close to the anterior end of the nudibranch are in the tightly coiled “pigtail” configuration. Figure 6: Detail of the Cerianthus sp. tentacle end-curling. THE VELIGER, Vol. 12, No. 4 [WopBerR] Plate 56 Figure 3 Figure 4 photographs by Don WosBER = oe eel ese Gone any en a +4 mA - eit re y i —— t THE VELIGER, Vol. 12, No. 4 [WopepeER] Plate 57 Figure 6 photographs by Don WosBER dhe 4 h , ‘: a oe it Phiaiea ceitt Maeg ls ; ieee : tt Ri . ‘ irons : i , ta ath a i - i Oh i re engl) inion ‘i : 7 j Kis i / “ it on 0 y a 0 p i OF a - ‘ 7 en i I Tey ay i tl i As fs é i jee ims itt a ( = A oy eh : a on 5 we » , H ' Bt 1 , : in 5 ‘ y i ‘ : ; } i j ow i 7 a, ; ve d ; ) of the Cambridge Mark Ila Stereoscan instrument at standard working distance, for example, any cylindrical shell whose length is less than 7mm can be photographed in a single exposure and the image fills a 34x34 inch negative. Specimens of up to 12 mm in length can be photographed in two shots with a montage print producing one continuous image for reproduction. All portions of such a shell will be in focus. The lighting effect will approximate that of natural sun- light on a cloudy day. Details will be visible in all areas and proper contrast control will prevent heavy shadow effects. Heliciform shells of 5 mm diameter can be photo- THE VELIGER Page 395 graphed in one shot. Even all parts of the apertural view will be completely in focus and details can be seen far inside the aperture. Montage photographs of 5 - 10mm heliciform specimens would be possible with 3 to 4 ex- posures. Since the specimen position can be altered under fine control, after the first photograph is taken, tilting of a few degrees and taking a second photograph will yield a stereo pair. Standard photogrammetric equipment such as the Wild ST-4 Mirror Stereoscope with parallax bar will enable relative depth measurements of surface topo- graphy and three-dimensional viewing of the specimen. At the lowest magnifications, the SEM can produce whole specimen illustrations of 5 to 7 mm shells. A magni- fication dial permits parfocal switching between 20, 50, 100, 300, 1 000, 3.000, 10 000, 30 000, and 50 000%: in order to inspect structural details. Figures 3 to 11 present part of such a series. At each step the specimen can be moved and adjusted, changing the angle of view or shifting to a different area. It is visible at all times unless moved out of the scanning field by too enthusiastic spinning of controls! If “lost”, returning to a lower magni- fication will relocate and enable retrieval of the strayed item. SEM OPERATION A series of electromagnetic lenses in a vacuum chamber focus a beam of electrons into an electron probe of 50 to Table 1 Comparative Instrument Performance Stereoscopic Compound Scanning Binocular Light Electron Microscope Microscope Microscope Resolution 20000 A 2500 A 200 A Field of view at: 20 X 12.5 mm circle not normally used 5 X 5mm 9.4 mm square 50 X 4mm circle 2.1mm circle 2X 2mm 3 mm square 500 — 0.21 mm circle 0.2 X 0.2 mm 5 000 X — — 0.02 X 0.02 mm 50 000 X = — 0.002 X 0.002 mm Depth of field at: 20 X 0.5 mm 50 X 0.2 mm 500 X —- 5 000 X — 50 000 x == not normally used + 20mm 0.02 mm 10mm 0.002 mm 1mm — 0.1 mm — 0.01 mm Page 396 THE VELIGER Vol. 12; No. 4 75A diameter. When this beam hits a surface, a few electrons are reflected, but a much greater number of low energy secondary electrons are emitted from the sur- face. These electrons are caught by a detector, the signal amplified several thousand times, and displayed as a spot on a long persistence phosphor cathode ray tube. Image brightness is determined by the intensity of secondary electron emission, with a low emission rate producing a dim spot and a high emission rate producing a bright spot. Use of a sawtooth generator scans the focused electron beam across the specimen. By making a quick scan, it is possible to build and maintain a complete visual image on the long persistence phosphor cathode ray tube. It is this electronic image that one watches. Movements of the specimen produce a few seconds of distorted image until the previous scan spots fade and a new image builds up. Producing a photograph requires use of a second cath- ode ray tube. In 100 seconds a single slow scan sweep is made onto a low persistence phosphor cathode ray tube. During this sweep the tube image is exposed to Polaroid Type 55 positive-negative film. After 20 seconds develop- ing time, a Polaroid black and white print plus a negative are available for inspection. If brightness, contrast, or ex- posure was miscalculated, then a second picture can be taken immediately. About 5 minutes are required for each exposure, including control adjustments after magni- fication and specimen positioning have been selected. About 10 publishable exposures can be made per hour. Since the image was scanned onto the cathode ray tube, attempts to enlarge a photograph more than 3 or 4 soon reveal the raster lines familiar to all TV watchers. En- largement of the upper right hand corner in Figure 1 to full picture size (Figure 2) illustrates this problem. Huge enlargements can be made by “fuzzing” the enlarger focus, but this results in significant detail loss. SPECIMEN PREPARATION AND SIZE LIMITS For dissipation of any electron charge that builds up on non-conductive surfaces, a conductive surface is de- sirable. Metallic substances can be examined directly, but biological specimens and fossils either must be given a conductive coating or else have the electron beam reduced to between 1 to 3 kV. Great loss of resolution in the image results from the latter option. Gold, palladium, aluminum, platinum and carbon are commonly used coat- ing materials. For effective viewing, a clean surface is essential. The specimens illustrated in this report were first cleaned of most dirt and incrustations by soaking overnight in water and then immersion for a few seconds into a water- filled tank of an ultrasonic cleaner. They were attached to a SEM stub with ordinary rubber cement and then placed in a vacuum evaporator. After pressure had been reduced to 10° torr, a 200 - 300 A layer of gold or alumin- um was vaporized electrically in a tungsten filament while the specimen was rotated slowly beneath the fila- ment. This allowed relatively even coating of complex surface topography. The gilded stub was taken from the vacuum evaporator and transferred into the SEM speci- men chamber. After pumping the electron column and chamber down to 10° torr, study was undertaken. Special equipment permits insertion of specimens up to 36 mm in size, but movements are greatly restricted and there is no increase in the field of vision. A specimen 12 mm square and 3 mm high can be handled with no restrictions on adjustments. MATERIALS Figures 1 and 2 are of a Moorea, Society Island species formerly known as “Charopa” modicella (Férussac, Explanation of Plate 58 “Charopa” modicella (FERUSSAG, 1840) Figures 1, 2: Faatoai Valley, Moorea, Society Islands. Bernice P Bishop Museum number 150377. Figure 1: diagonal view onto apex and early postnuclear whorls at 335 X magnification. Figure 2: enlargement of upper right area from negative of Figure-1 to dem- onstrate presence of raster lines. Ptychodon microundulata (SuTER, 1890) Figures 3-6: Turanganui River, Haurangi Range, Wellington, New Zealand. Dominion Museum, Wellington. Figure 3: General view of shell at 110 X. Figure 4: Suture between nuclear and postnuc- lear region at 1 100 X showing apical (upper left) and post-apical (lower right) sculpture types. Surface debris on right side can be used, to locate area photographed slightly above and to the left of center in Figure 3. Figure 5: Sutural area at end of nuclear whorls, 1 100 X, showing tentative start of microradial sculpture and chan- neled suture. Photograph taken at 18 whorl mark and showing post-apical sculpture at the end of the first complete postnuclear whorl. Figure 6: Detail of early apical sculpture at 3 350 X showing irregularly folded periostracum between two radial ribs. Folds can be matched with upper left portion of Figure 4 to establish size change. Plate 58 THE VELIGER, Vol. 12, No. 4 [Sotem] Plate 5 Figure 5 Figure 6 Vol. 12; No. 4 1840). It is an endodontid land snail belonging to the subfamily Charopinae, but is classified in a currently un- described genus. The specimen is from Faatoai Valley and is Bernice P. Bishop Museum number 150377. Remaining figures are of the New Zealand endodontid Ptychodon microundulata (SuTER, 1890). Specimens were collected by A.C. O’Connor in June 1949 from the Turanganui River, Haurangi Range, Wellington and preserved as dry specimens at the Dominion Museum, Wellington. I am deeply indebted to the authorities of the Bishop Museum and Dominion Museum for permission to study this material. RESULTS Dissections of Pacific Island endodontid land snails had revealed anatomically quite distinctive subfamilies whose shell sculpture appeared to be virtually identical under optical microscope examination. Initial use of the SEM was in search of conchological features that would serve as subfamily or generic identification criteria. Expansion of this work into studies of functional aspects of shell sculp- ture and investigation of endodontid shells from other areas soon followed. The Moorean specimen is tilted at about a 45° angle from a horizontal view. Figure 1 shows the apex and part of the first two postnuclear whorls in a shell measuring 3.25 mm in diameter with 44+ whorls. Actual width of the first nuclear whorl, which is not completely shown in Figure 1, is about 0.38 mm. Both apical and postnuclear sculpture are typical for the Pacific Island Charopinae. Ptychodon microundulata has a relatively complex and highly photogenic surface sculpture (Figures 3 to 11). All these photographs involve portions of a juvenile shell measuring 1.38 mm in diameter with 33+ whorls. Photo- graphs of the parietal lamella (Figures 12-15) were taken from a slightly larger individual by breaking away the palatal wall so that a direct view could be obtained of the entire lamella. Optical examination at 100 had shown that the juvenile showed essentially no worn spots on the apex and postnuclear whorls. More information could be obtained from this specimen than from larger examples with obvious surface wear. Adult size for this species is 1.71 - 1.97 mm, X is 1.86 mm, S. E. M. is 0.024 mm with 10 specimens measured. Figures 4 - 6 and 8 - 10 were taken during one visit to Alpha Research. Figures 3 and 7 were taken about two months later. Despite the specimen having been kept in a closed snap-lock plastic box, the concentration of par- ticulate matter in Chicago air is obvious. More than half of this debris accumulated after the initial study. THE VELIGER Payers 3)3)/| Figure 3 at 110 indicates essentially what can be seen under optical examination, although only a small part of the shell would be in focus at any one time. Major shell sculpture consists of prominent radial ribs on both the apex (first 13 whorls) and postnuclear whorls. The radial ribs are more widely spaced on the early apex, become much more crowded on the last portion and then change in appearance at the start of postnuclear growth. While the presence of some kind of microseulpture between the radial ribs can be seen, its frequency and nature cannot be determined. Although the texture of the interstices between the apical radial ribs looks different from the texture between the postnuclear radial ribs, no information is retrievable at 110><. Under optical examination, data gathering would stop. By switching the SEM to 1 100 and focus- ing on a suture between the first apical whorl and first postnuclear whorl (Figure 4), both microsculptures are displayed. The postnuclear portion (right and lower half) has a series of complex microradial riblets with enlarged “beads” that are arranged in spiral rows. Apical sculpture consists of irregular wrinkles and ridges with a “glassy” or “greasy” surface appearance. At 3350 (Figure 6) this apical sculpture is confirmed as consisting of a smooth film (= periostracum) that is irregularly folded. Rota- tion of the specimen to the point of demarcation between apical and postnuclear whorls (Figure 5) and examination at 1100 shows that tentative formation of the post- nuclear micro-radial ridges begins a short distance before the end of the periostracal film. Regular production of the micro-radial ridges starts at the end of this folded film and coincides with the increase in rib spacing noticeable in the early postnuclear section of Figure 3. Several other New Zealand endodontids and the Indo- nesian-Pacific Island Discocharopa have the same type of apical periostracum. An essentially equivalent type is seen in several European taxa that were photographed in co- operation with Dr. Gittenberger of Leiden. Interpretation of this structure is somewhat difficult. In physical char- acteristics, John A. Brown of Alpha Research informs me, this is the same pattern seen in many dried paint or var- nish films at equivalent magnifications. With this know- ledge, a hypothesis of origin can be suggested. Both the periostracum and calcified layer of the apical whorls are formed during a late embryonic stage. This takes place in liquid and the embryonic shell with firm calcification can be removed from unhatched eggs. Thus solidification of the calcium layer may occur while the periostracum is still bathed in liquid. If hardening of the periostracal layer was delayed until after hatching, then air drying of the periostracal film could result in the irregular folding Page 398 seen in the apical film. Differential frictional adherence of the film at the start of drying would result in the devel- opment of “tension folds” as it settled or shrank: into position on top of the calcium layer. Possibly the initial movement of the snail from the ruptured egg shell or brushes against minute particles in the environment could shift or distort the wet and pliable film, thus producing the irregularities. Even rotational movements of the em- bryo within the egg capsule might be enough to produce the distortions. Determination of what is the time rela- tionship between end of the apical sculpture and hatching will require study of young that were preserved minutes after hatching. While logic would suggest that hatching would coincide with the start of postnuclear sculpture formation, it is quite possible that it may precede hatching for a few ridges during the period when the embryo is actively moving but has not yet broken through the egg shell. This could be determined very easily with the SEM through study of pre-hatched, hatching, and recently hatched shells. Returning to the postnuclear sculpture, at 335 x (Figure 7) it is seen to consist of high major ribs that stop on the suture edge. From 3 to 7 micro-radial riblets lie in the trough between each pair of major ribs on the early sections. They also are present on both the sides and tops of the major ribs. Major ribs are 4 to + as wide as the interval between each pair and the spacing varies slightly from rib to rib. There are fewer micro-riblets between crowded than between widely spaced ribs. This leads to the conclusion that depositional timing of the micro-rib- lets and major ribs is independent. That is, production of a major rib is not started after “x” number of micro-rib- lets, but that control of these two sculptures is separate. Data on this aspect will be presented elsewhere. Optical examination of the shell had permitted counting the major ribs on the body whorl with an accuracy of +1. Knowing that the shell diameter was 1.38mm, simple multiplication by 7 produced the shell circumference' of THE VELIGER Vol. 12; No. 4 4.34 mm. Division of the 124 ribs on the body whorl by the circumference in mm established there are an average of 28.6 major ribs per mm on the body whorl periphery. By shifting to the body whorl periphery about 4 whorl behind the aperture (Figures 8 to 11), it was possible to examine structural details of the postnuclear microsculp- ture. The basic orientation is looking down onto the body whorl top and curvature of the periphery with a slight angling towards the aperture. Whenever repetitive surface sculpture is present, viewing around a curve permits simul- taneous inspection of the sculpture elements from various angles. This greatly aids interpretation and allows mental stereoscopic reconstruction of complex topography. In Figure 8 the magnification of 1 100 shows about 0.15 mm of body whorl periphery. Each major rib is seen to have a single, high, posteriorly recurved, slightly sinuated lamellar extension. Inspection at 3350 in Figure 9 shows that this structure arises from the top of a micro- radial and that its surface shows traces of very irregular grooving. As the snail moves through leaf litter, this lamellar extension would brush against fine particles in the environment. Minute grains of rock and soil would rub against this reflected edge. As the snail moved forward, sharp edges on the miniature boulders would score or abrade the surface, producing the irregular grooves seen on its outer edge. This lamellar extension is not present during the first postnuclear whorl (Figures 3 to 5) and only weakly developed on the second postnuclear whorl (Figure 7). Most major ribs show partial evidence of minor extensions on the microradials just before and just after the major extension (Figures 8 to 10). An under- ' Although the actual measurement should have been one volution of the logarithmic growth curve to establish periphery length, this simple calculation is an adequate approximation. Rib counts are the same at the suture and periphery of a whorl although the linear distance is not the same. Bias is essentially the same for every specimen and is not considered significant. Explanation of Plate 59 Ptychodon microundulata (SuTER, 1890) Figures 7-11: Turanganui River, Haurangi Range, Wellington, New Zealand. Same specimen used in Figures 3 - 6. Figure 7: Early apical and two whorls of post-apical sculpture at 335 %. Note suture and “beaded” appearance of microradials except at curve into suture. Figure 8: Periphery of body whorl, one-quarter whorl behind aperture, at 1 100 X. Note change in appearance of microradials as the curvature increases. Figure 9: Peripheral view between two major ribs at 3 350 X showing change in microradial buttress form and structure of microsculpture. Figure 10: Detail of microsculp- ture on periphery at 11 100 X. Note change in buttress height and shape on ascending side of major ridge at right margin of photo- graph. Figure 11: Two “beads” on a microradial ridge at 33 500 X showing the ascending buttress structure (apical direction to left of figure, apertural direction to right). Figures 9 to 11 are enlarged details from the area shown in Figure 8. Tue VELIGER, Vol. 12, No. 4 [Ss ] 7 oLEM] Plate 59 Figure 11 Vol. 12; No. 4 THE VELIGER Page 399 standing of this becomes possible after analysis of the microsculpture. At magnifications of 1 100 or less, particularly when viewing at essentially a vertical angle (Figures 4, 5, 7) the microelements appear as thin radial ridges with a series of “beads” arranged in spiral rows. Part of this is an artifact of electronic scanning. In Figure 8 at 1 100, the lower left part of the photograph shows essentially a vertical view. Note the beaded appearance of the sculp- ture. Since the intensity of a scanned spot depends upon both the angle at which the electron probe hits the sur- face and the distance secondary electrons must travel to the detector, a higher spot in direct path of the electron probe will register much brighter than a lower surface that is hit at an extreme angle by the probe. The elevated “beads” thus register very brightly, while the sides and significantly lower “trough” areas appear as dark spots. As the angle of the electron probe increases towards the center of Figure 8, the complexity of this sculpture is revealed. At the higher magnifications of 3 350 (Figure 9), 11 100 (Figure 10), and 33 500 (Figure 11) this can be interpreted. A network of spiral and radial ele- ments comprise the microsculpture. The elevated beads are connected radially (bottom to top in Figure 10) by a narrower (Figure 11) buttress with rounded upper mar- gin that gradually rises up on one side of the elevated point and descends on the other. As these radial rows approach the upsurge on the apical side of a major ridge (right part of Figure 10), the radial buttress narrows and becomes elevated above the rounded beads. Finally the uppermost row on the major rib surface extends into the reflected lamellar extension. Spiral elements (left to right) in this sculpture consist of a low ridge that sweeps up on the apical side in an accelerating curve to meet the radial buttress and extends above it as a “bead”. Generally it drops off extremely rapidly on the apertural side of the bead, but Figures 9 and 11 show that a more gradual drop is possible. At the bottom of the trough between each pair of spiral butt- resses are a few irregular folds. Figure 11 shows that these are sometimes present on the elevated buttresses. A pos- sible explanation is that these are periostracal tension folds. Growth proceeds from left side to right side in these photographs, so that the less elevated portion of the microradial sculpture is deposited first. With subsequent extreme elevation of the radial buttress, even slight de- parture from the exact template relationship of the peri- ostracum and underlying calcium deposition would create stress in the periostracal layer. Hence the folds in this region could be analogous to the apical folds, although at a much lower level of visibility. Obviously the use of 300 to 30000 SEM magnifica- tions permits gathering infinitely more data concerning the composition and growth patterns of shell sculpture than is available using optical instruments. The previous standard of description might refer to such a species as “radiately costulate” or “major growth riblets about 21 per mm on body whorl with a few finer riblets between”. Now it is possible not only to study the exact physical structure of such sculpture, but to pose questions con- cerning its mode of formation, to measure its relative prominence, and to compare functioning effectiveness of this sculpture in different taxa. Equally important data can be obtained concerning the structure of apertural barriers in small land snails. These occur in many different land snail families, sometimes in adults and sometimes in juveniles, but are particularly common in endodontid land snails. Figures 12 to 15 illus- trate details on the posterior half of the major parietal lamella in Ptychodon microundulata. Previous illustrations (Surer, 1890, plt. XIV, fig. 4c; Surer, 1915, plt. 27, fig. 8c; and Ciro, 1969, p. 197, fig. 12) show very little detail, either portraying the lamella as smooth or with serrated edges. There are 3 rows of large denticles on the expanded margins of the lamella, with the denticle points directed towards the aperture (Figure 12). Two rows are on the lower margin, one on the upper. Even at 335 (Figure 12), but particularly at higher magnifications (Figures 13 to 15), one can see that a thin transparent film connects the points. This is dried mucus. Frequently such mucous sheets are found on the shell surface or partly covering apertural denticles in specimens that were col- lected alive, but then simply air dried and kept in a collec- tion tray. Under these circumstances, the mucous traces caused by snails crawling over each other in the collecting vial, or the patch of mucus left as the snail retreats into the shell before dying of desiccation, hardens into a sheet that is almost impossible to loosen by soaking or ultrasonic cleaning. Specimens that were drowned and preserved in alcohol have loose mucous coatings that are readily cleaned. Since this shell was a live collected, air dried spe- cimen, the mucous sheet was present and could not be removed. Irregularity in angulation, size and position of the den- ticles is evident. At 1100, study of the lower two rows (Figure 13) shows that the interstitial area contains mi- Page 400 nute crystalline structures. This is particularly clear in the lower left portion. In the central area of this photograph, the overlapping mucous sheet obscures details. Shifting study to a lateral view of the upper denticle row in Figure 14 at 1100 and Figure 15 at 3350 indicates the na- ture of the growth pattern. The denticles are simply elongated prismatic aragonite rods. Figure 15 shows that the low crystalline structures in Figure 13 are shorter crystals that parallel the growth of major denticles. In the upper left part of Figure 15 the surface texture is the same as prismatic growth area surfaces figured by WISE & Hay (1968b, p. 422, fig. 8). This is the smooth interdenticle row area shown in Figure 12. Note the slight discontinuity between this prismatic growth surface section and the aragonite rods. This is typical of such an interface and has no special significance. Other lamellae on the columellar and palatal walls differ in having smooth surfaces, even at 3000 magnification. SUMMARY Scanning electron microscopy permits whole specimen photography of mollusks up to 7 mm in size, with the image filling a 3534 inch negative. Since the depth of field obtainable is several times greater than the height or width of the picture, all areas will be in sharp focus. Parfocal changing of magnification between 20 and 50 000>, combined with the ability to tilt, shift and rotate the specimen being observed, permit examination of suc- cessively finer detail, stereoscopic photograph preparation and examination of the same structure from different angles. As a result, questions that previously could not be asked, now may be answered quickly. Molluscan shells present a frozen record of growth during the life of that individual. Details of this past are readily visible by electronic anal- ysis. Ptychodon microundulata is presented as a partic- ularly fine example of complex sculpture, together with some of the questions and hypotheses that result from examining this species. THE VELIGER Vol. 12; No. 4 LITERATURE CITED BLAKER, ALFRED A. 1961. Basic lighting for shell photography. 3 (3): 69-72; plt. 12; 3 text figs. Cumo, Frank M. 1969. Classification of the New Zealand Arionacea (Mollusca: Pulmonata). II. A revision of Charopa subgenus Ptychodon. AncEy, 1888. Records Domin. Mus. 6 (14): 175 - 258; 11 plts.; 34 text figs. (23 May 1969) Ersen, H.K., G. Fiays « A. SIEHL 1968. Uber die Schalenstruktur von Monoplacophoren. Akad. Wiss. Lit. Abhandl. Math.-Naturwiss. K]., Mainz 1968 (1): 1-24; plts. 1-17 Hay, WiLiiAM W. & Puiuie A. SANDBERG 1967. The scanning electron microscope, a major break-through for micropaleontology. Micropal. 13 (4): 407 - 418; plts. The Veliger (1 January 1961) il, 2 (October 1967) SoLem, ALAN 1969. ... in his dim, uncertain sight. Bull. Field Mus. Nat. Hist. 40 (3): 7-9; 12 figs. SuTER, HENRY 1890. Descriptions of new species of New Zealand land and fresh-water shells. Trans. Proc. New Zealand Inst. for 1889, 22: 221 - 230; pits. 14, 15 (May, 1890) 1915. Manual of the New Zealand Mollusca. Atlas of Plates, 72 plts. Wellington (John Mackay) . Taytor, Joun D., W. J. Kennepy « A. Hatu 1969. The shell structure and mineralogy of the Bivalvia. In- troduction. Nuculacea- Trigonacea. _ Bull. British Mus. (Nat. Hist.), Zool. Suppl. 3: 1-125; 77 figs.; 29 plts. THompson, Tuomas E. « H. E. Hinton 1968. Stereoscan electron microscope observations on opistho- branch radulae and shell-sculpture. Bijdr. Dierk. 38: 91 to 92; plts. 1-4 WIsE, SHERWOOD W. 1969. Study of molluscan shell ultrastructures. In: Scanning Electron Microscopy/1969, Proc. 2.4 Ann. Scanning Electr. Microsc. Symposium, pp. 205-216; 23 figs. Chicago, Illinois (IIT Research Inst.) (April 1969) Wist, SHERWoop W. & WILLIAM W. Hay 1968a. Scanning electron microscopy of molluscan shell ultra- structures. I. Techniques for polished and etched sections. Trans. Amer. Micros. Soc. 87 (4): 411-418; 8 figs. 1968b. Scanning electron microscopy of molluscan shell ultra- structures. II. Observations of growth surfaces. Trans. Amer. Micros. Soc. 87 (4) : 419 - 430; 17 figs. (1 April 1969) Explanation of Plate 60 Ptychodon microundulata (SutTER, 1890) Figures 12-15: Parietal lamella from adult specimen in same set as juvenile photographed in Figures 3 to 11. Figure 12: Posterior portion of parietal at 335 X, viewed slightly from below. Figure 13: Double rows on lower edge of lamella at 1 1000 X. Note fine crys- talline rods visible between major denticles. Figure 14: Lateral view of upper row at 1 100 X. Figure 15: Lateral view of upper row at 3 350 X. Note mucous film and aragonite rods. TuHeE VELIcER, Vol. 12, No. 4 [Sorem] Plate 60 Figure 14 Figure 15 eh if ie Vol. 12; No. 4 THE VELIGER Page 401 The Effect of Wave Impact on Some Aspects of the Biology of Sea Mussels J. R. E. HARGER - Department of Biological Sciences, University of California at Santa Barbara ' (9 Text figures; 15 Tables) INTRODUCTION THE ABSENCE OF a simple wave impact measuring device has hampered the efforts of ecologists in comparing con- ditions among different intertidal habitats for some time. Moore (1935) has made use of the percentage of the year’s winds blowing into the angular aperture of a locality; SourHwarp (1958) used the occurrence of waves washing over the breakwater at Plymouth, coupled with known wind records, to generate a wave index; BALLANTINE (1961) has outlined a biologically defined exposure scale for the comparative description of rocky shores; and finally Erion Jones & DOoMETROPOULOS (1965) have used an apparatus consisting of a drogue at- tached to a spring dynamometer to record drag produced by passing waves. (I) MEASUREMENT or WAVE IMPACT In investigating the effects of wave action on the biology of two species of mussels (Mytilus edulis Linnagus, 1758 and M. californianus Conrap, 1837) on the coast of Southern California, I made use of a device for measur- ing wave impact. This consisted of a smooth 6 inch long nail, a spring steel “c” clip, and a metal plate of 1/16 inch gauge steel. A 4+ inch diameter hole was drilled in the center of the plate which was then passed up the nail shaft until it rested against the head. A “‘c” clip was then threaded up the shaft of the nail to the bottom of the plate so preventing the plate, when released, from falling down the nail (Figure 1). 'The nail was then fixed into an “intertidal” rock or pier piling so that the head, and metal plate supported by the “c”clip, projected into ' Present address: Department of Zoology, University of British Columbia, Vancouver 8, British Columbia. the prevailing wave motion. Wave action, during one tidal period, then forced the metal plate and “‘c” clip down the shaft of the nail. The distance through which the plate is moved depends on 3 factors: size of the plate, frictional resistance afforded by the “‘c” clip, and strength and frequency of wave impact. The first 2 factors can be controlled; all that is necessary is to insure that such a combination of plate size and clip strength is used, at a particular geographic location, that the plate will not be forced completely down the nail during one tidal period. The force exerted by heavy storms can be estimated with this device, simply by making the plate very small. metal — Z? plate 6” nail Figure 1 Wave impact measuring device Page 402 The force of wave impact for one (or more) tidal cycles is calculated in the following manner: a = area of the plate in cm’ f— force required to overcome the friction of the “c” clip, measured by pulling it down the nail with a spring balance (in kg) d= distance the plate is moved (in cm) Wave force = (f/a)d. kg-cm/cm? If the wave force is to be compared at several locations, nails must be set out at each place within the same tidal period. (I found that an individual “c” clip could be used only 2 or 3 times and that the nail shafts must be kept free of burrs and nicks.) Table 1 lists values ob- tained for wave impact, over three 24-hour periods, from 5 locations. These areas are all situated within a few miles of the City of Santa Barbara, on the coast of Southern Califor- nia (Figure 2). Stearns Wharf is located at the entrance ‘San Francisco se UCSB Santa Barbara Figure 2 Location map showing Santa Barbara and study areas 1. Ellwood Rocks 2. Ellwood Pier 3. Goleta Point 4. Stearns Wharf 5. Carpinteria of the Santa Barbara harbor and is quite sheltered. Ell- wood Pier (property of Signal Oil and Gas Co.) is a large pier, almost $ mile in length, situated some 14 miles west of Santa Barbara, on open sandy shore. The steel pilings of this pier extend from the intertidal surf zone out to a depth of about 40 feet. These pilings sup- port large intertidal clumps of mussels which are com- prised of both Mytilus californianus and M. edulis. Ell- wood Rocks are part of the shore line immediately adjacent to Ellwood Pier, and Goleta Point is an out- cropping of rock just below the campus of the University THE VELIGER Vol. 12; No. 4 of California at Santa Barbara (10 miles west of the City of Santa Barbara). These points were chosen for easy access and because a series of exposures ranging from sheltered (Stearns Wharf) to exposed (Goleta Point) were obtained. oa During the recording period, winds were light (5-8 knots on-shore) but a heavy swell was running producing breakers between 4 and 5 feet in height on the local sand beaches. From Table 1, it appears that the force of wave impact suffered by Ellwood shore is 4-5 times that in- curred by the outer end of the adjacent Ellwood Pier. Within the pier itself, a particular sheltered position (in- take pipe) received less than 4 as much force as nearby open pilings and Goleta Point experienced some 13 to 18 times more wave impact than the Ellwood shore. The recorders at Ellwood Shore were driven into the front face of a 3 foot high hemispherical boulder (8 feet in diameter) which projects from the relatively gently sloping lower mid-littoral (the recorders in all locations were placed in the lower mid-littoral). The recording site at Goleta Point was a 5 foot high vertical rock face situ- ated in the lower mid-littoral region. This rock face is so placed that a swell hitting it at half tide may throw spray to a height of 12 to 15 feet. These measurements indicate that the impact force ex- perienced by any group of organisms on an exposed shore line depends on the strength of the waves, on the aspect of the rock face to which they are attached, and on whether there is a beach, or other rocks, to seaward which can absorb some of the force before the waves reach the or- ganisms. There is a large difference between the exposure value obtained from Stearns Wharf (sheltered) and that from Ellwood Shore (exposed) (see Table 1). However, on the open shore, rocks in different positions (Ellwood Rocks and Goleta Point), are exposed to wave impact forces which differ from each other by as much as the difference between the sheltered harbor (Stearns Wharf) and the stretch of exposed coast (Ellwood Rocks) impact values. Taking into account the difference between the front (seaward) and rear (landward) faces of intertidal rocks, it is clear that the intensity of wave impact on an exposed intertidal shore must vary greatly. Wharf pilings projecting from natural intertidal regions suffer more frora wave impact than deep water pilings. This difference between deep and shallow water pilings has also been reported by Bascom (1964). On pilings, in general, wave impact is greatest at the mid-tidal level and less at higher and lower levels. A method similar to that reported here of recording the pressure exerted by waves against structures was used by Thomas Stevenson in 1842. Bascom (op. cit.) reports Vol. 12; No. 4 THE VELIGER Page 403 Table 1 Mean wave impact values obtained on three days from four different sites (The unit of measurement is kg—cm/cm?) 12 Dec. 1966 13 Dec. 1966 15 Dec. 1966 Mean Mean Mean Wave Wave Wave Place Impact Sample Impact Sample Impact Sample Values Size Values Size Values Size Stearns Wharf, Santa Barbara Harbor 0.012 3 0.014 3 0.022 3 Ellwood Pier (Intake Pipe) 0.048 4 0.055 1 0.060 1 Ellwood Pier (Outer Pilings) 0.105 2 0.152 5 0.199 4 Goleta Point <3.769 6 9.160 3 9.187 3 Ellwood Rocks 0.495 5 0.590 5 0.766 6 that the instrument used “... consisted of a plate six inches in diameter facing into the waves, mounted on a stiff horizontal spring. Behind the spring was a rod held by a friction grip in such a fashion that it would move as the plate moved but remain at the maximum distance which the plate pushed it. As each increasingly large wave impacted against the plate, the rod would be pushed to a new position. The distance moved times the spring constant gave the maximum wave (single) force exerted on the plate ...” The modern “professional” pressure gauge which is now used by engineers to measure the force exerted by waves on pilings, piers and shoreline structures is described by Bascom (op. cit.) as “consisting of a stack of thin plates of tourmaline crystal set in a strong metal case. When subject to pressure, this gage produces a small charge of electricity which can be amplified ...” In the same book, data which indicate that there is a substantial increase in the force exerted on a piling as waves change from swell into breakers and then foam- lines are presented. Bascom also comments that “measure- ment of wave forces on pilings is complicated by the con- tinual reversal of direction of the water as the crest moves in one direction and the trough moves in the UNS, goo Table 2 Comparison of growth increment data: Mytilus californianus and Mytilus edulis from exposed and sheltered cages set at the mid-tide level on the outer end of Ellwood Pier. The mussels used in the experiment were all originally between 3 and 4cm long. Growth period was from December 1966 to March 1967 All measurements are in centimeters Note: one asterisk (*) indicates significance at the 5% level, two asterisks (**) significance at the 1% level and three asterisks (***) significance at the 0.1% level. Abbreviations of statistical terms are those used by J. C. R. Li (1964). § E S 2 2 form.) © 12} EN F a Group a as A 3,155 1. Mytilus edulis from plastic cage 0.94 0.57 33 49.01% 2. Mytilus edulis from wire cage 0.34 0.27 44 3. Mytilus californianus from plastic cage 1.53 0.72 42 4. Mytilus californianus from wire cage 1.44 0.56 40 F 1,155 Individual D. FE Tests 1.2/3.4 108.56*** 3/4 0.55N.S. 1/2 20 Dee Page 404 THE VELIGER Vol. 12; No. 4 The advantages of the wave impact measuring device described in this paper lie chiefly in its simplicity and low cost. By using several instruments at several locations an ecologist can get a quick (although perhaps somewhat rough) estimate of the wave impact force acting on dif- ferent parts of the intertidal region. (II) EFFECTS or WAVE IMPACT on THE BIOLOGY oF Mytilus edulis ann Mytilus californianus (A) Growth The effect of wave impact was investigated by placing equal numbers of each species of mussel (individuals 3 - 4 cm in length) in open mesh wire cages (exposed treat- ment) and in cages of partly occluded sheet plastic (pro- tected treatment) and recording subsequent growth. The first type of cage was constructed from 4 inch mesh (1.27 cm) galvanized hardware cloth and was cylindrical in shape (diameter 7 inches {17.78 cm}) with a height of 8.5 inches (21.5 cm). The various components (wire sec- tions, etc) used in construction were laced together with braided nylon cord and the entire structure then coated with epoxy resin. This treatment served to give rigidity to the nylon binding and at the same time to cut down any leaching of zinc ions which might affect the enclosed mussels. The second cage was made of plastic kitchen colanders (10 inches {25.4cm}) in diameter placed face to face and lashed together at the edges (the maxi- mum diameter of the holes in a colander was } inch {0.963 cm}). The cages were suspended at the mid-tide level on the extreme outer edge of Ellwood Pier. After 4 months (De- cember, 1966 to March, 1967), the growth increment Table 3 Comparison of growth increment data: Submerged Mytilus edulis from a plastic cage, a wire cage and a naturally occurring clump of mussels growing on an electrode cable Original shell length has been used as the independent variable and growth increment as the dependent variable. All measurements were made in centimeters. 2 Fh BSS 2 ag a, 2 th ASS Group on Regression Equation z a} = 3 ti OS 7) aX 1. Mussels from 27 Y=0.005+0.15X 3.04N.S. 1.011 1.96N.S. clump on cable 2. Mussels from 33 Y =0.045+0.17X 1.153 wire cage 3. Mussels from 42 Y=0.491 + 0.08X 1.046 plastic cage Table 4 Comparison of growth increment data: Submerged Mytilus californianus from a plastic cage, a wire cage and from a naturally occurring clump of mussels growing on an electrode cable Original shell length has been used as the independent variable and growth increment as the dependent variable. All measurements were made in centimeters. ay oat B hgh: rege Mae Group a & Regression Equation i) ies 2 g i ae <2x 1. Mussels from 11 Y =0.74+0.023K 0.37N.S. 0.879 1.08N.S. clump on cable 2. Mussels from 28 Y =0.64+0.072X 1.092 wire cage 3. Mussels from 43 Y=0.52+0.089X 1.072 plastic cage a —————0———_—_—_—_—_—_—_—_— Vol. 12; No. 4 THE VELIGER Page 405 for each mussel was recorded. It was found that the Mytilus californianus populations grew much faster than those of M. edulis (Table 2). There was no significant difference in the growth rate of M. californianus from the different cages, but M. edulis from the wire cages grew 4 the amount shown by the animals in the plastic colander. This difference was attributed to the effect of wave impact which presumably acted more severely on the mussels in the wire cage (the openings in the wire mesh account for approximately 92% of the cage surface) whereas the walls of the colanders, because they were constructed of sheet plastic containing relatively small holes (the holes account for approximately 15% of the cage surface) would diminish the impact of breaking waves. The fact that no significant difference in growth can be detected between M. californianus from the shel- tered and the open cages would seem to indicate that this species is not sensitive to the exposure differences between the two cages. A further test was conducted at the same time to determine the effect these two cages might have on the growth of both species of mussels when placed below low water where the effects of wave impact are absent. An additional comparison was made in this case between the two treatments using caged mussels and mussels growing naturally within submerged clumps at- tached to insulated cables suspended from the pier. Growth for each species was not detectably different for any of these treatments (Tables 3, 4), which indicates that caging itself does not hinder growth under these conditions. (B) Size Figure 3 illustrates the relationship between the maxi- mum size of Mytilus edulis occurring naturally at several localities and the corresponding wave impact values. It can be seen that small mussels are associated with high, and large mussels with low values. This relationship is consistent with what one might predict from knowledge of the force required to remove different sized individuals of M. edulis from a rock surface. This force was recorded by fastening either a battery clip to, or looping a piece of cord around a mussel and then hooking a spring scale through the clip or a loop on the cord and noting the force required to dislodge the mussel as the scales were pulled firmly away from the rock. Analysis reveals (Fig- ure 4, Table 5) that the force necessary to tear loose the two species of mussels was significantly different, with M. californianus requiring more force when similar sized mussels are compared. Data relating to a third species of mussel, Septifer bifurcatus (Conrap, 1837) are also included with the analysis given in Table 5 and illustrated in Figure 4. These mussels occur intertidally on the Santa Barbara coast but are physically quite small — the maxi- mum length attained being about 3.5 - 4.5m long. The (cm) Maximum Size of Mytilus edulis 0.0 0.10 1.00 10.00 Wave Force (kg — cm/cm?) Figure 3 Relationship between wave impact values and the maximum size of Mytilus edulis occurring at the measurement sites 1. Stearns Wharf 2. water intake pipe at Ellwood Pier 3. outer end of Ellwood Pier 4. Ellwood Shore 5. Goleta Point force required to remove an individual from a rock face is greater than that required to remove a similarly sized M. californianus individual. (Populations of Septifer are found intertidally only in exposed conditions. ) The relationship indicated for Mytilus californianus (Figure 4) is strictly linear, even for the largest mussel tested (10 cm long), but the curve obtained for M. edulis flattens out once a length of 4-5 cm is reached, so that the force required to remove a 10 cm individuai is the same as that required to remove a 5cm mussel. The larger mussels used to provide points on this curve all came from various positions on Ellwood Pier, some from pilings and some from large subtidal mussel clumps which had formed on zinc electrode cables hung from the pier. Since these cables do not touch the bottom, starfish are unable to find and attack the mussel clumps, so, in Page 406 26.0 Force (kg) Shell area (cm?) Figure 4 The force to remove mussels from the open shore plotted against a correlate of shell area (length X breadth). [Shell measurements in centimeters] Septifer bifurcatus represented by solid triangles, Mytilus californi- anus by solid circles and Mytilus edulis by dashes. Crosses indicate values for both M. californianus and M. edulis. Regression lines are fitted by least squares (see Table 5) the absence of predation these mussels may reach an extremely large size in the relatively quiet water (M. californianus up to 30cm and M. edulis up to 15cm long). Only mussels unencumbered by the byssal threads of others were used in the tests; even so, it might be argued that since the large mussels came from a complete- ly different environment from that of the shore mussels then the relationship in Figure 6 is not representative of a shore population and that it is therefore invalid to draw inferences from it reflecting the disposition of such populations. It was however impossible to find large in- dividuals of M. edulis on the shore, therefore, sub-tidal specimens were used. In an attempt to counteract the THE VELIGER Vol. 12; No. 4 above objection a laboratory test was performed, the results of which are presented in Table 6 and Figure 5. Individuals of both species were placed for 3 weeks on the bottom of tanks containing running sea water. The force required to remove them at the end of this time was then recorded. The relationship is essentially the same _as that obtained by using the naturally set animals, how- ever, since these mussels established fewer byssal threads the dislodging force was generally lower. Since small Mytilus edulis survive wave impact with apparent success, a comparison of the two species involv- ing animals of up to 4.cm in length was also made, The results show clearly that even at this size M. californianus holds on more strongly than does M. edulis (Table 7). From these results one might predict that only small individuals of Mytilus edulis could survive in “exposed” situations and that conversely large specimens (5 cm and over) would be likely to occur in sheltered places such as harbors, etc. This is borne out by observations along the coast of Southern California. Mytilus californianus on the other hand is able to attach itself such that a relatively constant force (in proportion to its shell area) Shell Area (cm?) Figure 5 Force to remove mussels from laboratory tanks (constructed from resined fibre glass) plotted against a shell area correlate (length < breadth). @ — Mytilus californianus; O-—M. edulis. Shell measurements in centimeters Vol. 12; No. 4 THE VELIGER Page 407 Table 5 Comparison of the force required to remove different sized, naturally set, individuals of Mytilus californianus, Septifer bifurcatus and Mytilus edulis A measurement correlated with shell area (length X breadth) has the shell valves (from the dorsal to the ventral edges) : length was been used as the independent variable and force required to remove measured as the maximum distance between the anterior and pos- mussels (measured in kilograms) the dependent variable. terior edges of the valves, i. e., from hinge(umbo) to siphon regions. The breadth measurement was made across the broadest part of All measurements were recorded in centimeters. Bao 4 OG sy ee x e ee uae eer | Oa! Terk rou 3 egression Equation wWeWN oh av 2) w g q n z S 4 1. Septifer bifurcatus 32 Y=1.71+1.14X% 134.28*** 14.513 138.01*** 2. Mytilus californianus 111 Y=2.14+0.58X 8.768 3. Mytilus edulis 125 Y=3.00+0.10X 4.171 F Individual D. F Test on B 1,262 1/2 2.50N.S. 2/3 262.46*** Individual D. F. Tests on Adjusted Means 1/2 4.03* 2/3 267.95*** Table 6 Comparisons between the forces required to remove A correlate of shell area (length breadth) has been used as the different sized individuals of Mytilus edulis and Mytilus independent variable and force required to remove the mussels B . Frontech : ll Alsip En (measured in kilograms) as the dependent variable. Length meas- californianus a ter pt SPECIES WERE. OWE ESO aUae urements made on the mussels were in centimeters. the inside of laboratory tanks Pid a) n 3 S a £8 Bet BEX wh Group Fie Regression Equation = a Saat | = 2 breadth) has been used as the independent variable and force required to remove the mussels individuals of Mytilus edulis and Mytilus californianus ee : Senn dhe ouan drone when bath are less dhan 997 Gan (measured in kilograms) the dependent variable. Length measure- P ; : ments made on the mussels were in centimeters. in length Means at Slopes F 1,58 Adjusted & a Group Fie Regression Equation 1. Mytilus edulis 20 Y =0.26 + 0.604X 3.75N.S. 2.064 HOO Re 2. Mytilus californianus 42 Y =0.28 + 1.183% 3.253 Page 408 THE VELIGER Vol. 12; No. 4 is necessary to detach it, consequently all sizes (at least those up to 10cm long and probably longer) are able to withstand wave impact equally well and thus no size limitation seems to be imposed on this species by wave action. (C) Body Weight Body weight is a further characteristic of mussels which varies with the force of wave impact. This was demon- strated by collecting a group of mussels from each area in which wave impact data were recorded. After recording individual dry body weights, an adjusted (for shell length) mean dry body weight for each group was determined. Figure 6 shows that the body weight of Mytilus edulis varies inversely with the amount of wave impact to which it is exposed. 0.8 0.7 0.6 0.5 Adjusted Mean Dry Body Weight (gm) 5 Io 20 Wave Force (kg — cm/cm?X 10?) 3o40 Figure 6 Plot of the square root of dry body weight of Mytilus edulis (adjusted to a shell length of 4.037 cm) against wave force values. The latter values were obtained from four geographical positions (Positions 1 to 4 in Figure 3). Values obtained on three different days (vy, mw, @ ) are plotted for each position. The bar repre- senting variation of body weight is proportional to twice the standard error of the mean on each side It was not possible to obtain such a precise relation- ship for Mytilus californianus — it seems that in spite of the amount of wave impact experienced, this species maintains a relatively constant body weight. This is not to say that the body weight of M. californianus from different areas is constant, because this is not so. A large amount of variation exists here and the closest thing to a general statement which can be made with regard to this (based on numerous separate samplings from a num- 60 80 ber of areas) is that the body weight of M. californianus from an exposed area (Ellwood Shores) is likely to be less than that from a relatively sheltered area (Ellwood Pier pilings) (Table 8), but this is not always the case. (D) Production of Check Rings Both species develop “check rings” the number of which is directly related to the length of the shell. This may be a structural modification conferring additional strength to the shells. In Mytilus californianus these rings are numerous and prominent throughout the length of the shell, and give it an appearance much like finely corrugated iron. The shells of M. edulis on the other hand, usually have few rings and appear quite smooth in com- parison to those of M. californianus. For M. californianus the number of check-rings per unit length of shell varies 51.0 44.0 37.0 isc) S ° Number of Check Rings e) 16.0 0.00 0.80 1.60 2.40 3.20 4.00 4.80 5.60 Shell Length (cm) Figure 7 Plot of the number of check rings against shell length for Mytilus californianus taken from a clump of mussels at Carpinteria reef. Solid squares represent mussels from the inside of the clump and hollow squares, mussels from outside the clump. Regression lines are fitted by least squares (see Table 9) Vol. 12; No. 4 THE VELIGER Page 409 Table 8 Comparison of dry body weight data: Mytilus californianus from two “exposed” positions, Ellwood Shore and Carpinteria Reef and from two “sheltered” positions, Stearns Wharf and Ellwood Pier The independent variable is shell length (measured in centimeters) and the dependent variable is body weight (in grams). All body weight measurements have been transformed by taking the square root of the variable. #19 a o ih & g < = S EN ; GaN BR mA Group 3 Regression Equation a Ge = S N oa) 1. Ellwood Shore 67 Y=-0.17+0.179X 6.34* 0.816 40.75*** . 2. Carpinteria Reef 74 Y =-0.27 + 0.233% 1.008 3. Ellwood Pier 37) Y =-0.21 + 0.238X 1.097 4. Stearns Wharf 30 Y =-0.26 + 0.226% 0.979 F Individual D. FE. Test on B 1,220 1.2/3.4 6.37* Individual D. F Tests on Adjusted Means 1.2/3.4 51.94%** Table 9 Check ring comparison: Mytilus californianus from inside and outside a clump at Carpinteria Reef The independent variable is shell length (centimeters) and the dependent variable is the number of check rings. Group Sample Size 1. Outside 64 2. Inside 60 Regression Equation Y =-2.05+ 7.05% Y= 0.87+9.00X% no =) 4 © Gas o Sen a a — o = 2 Zsx 22.24*** 19.087 290.79*** 27.884 Table 10 Comparison of the growth increase shown by two groups of mussels growing inside a plastic colander placed below low water at Ellwood Pier Members of the first group were originally growing inside a clump of mussels at Carpinteria Reef, those of the second group were outside the same clump. The recorded independent variable was growth increment (in centimeters). Zs © S Ries! a a P= for, v (=) Group S a = Ba oer nQ Z 1. Mussels from 0.59 0.33 38 0.05N.S. inside clump 2. Mussels from 0.57 0.29 44 outside clump with geographical location and even from different situ- ations within a clump of mussels. It seemed that this variation in check-ring frequency was in some way related to the degree of disturbance, harassment or interference that a particular animal had experienced during its growth period. The first step in testing this hypothesis was to obtain mussels from inside and outside a clump from a moder- ately exposed shore at Carpinteria Reef (a large flat out-cropping of rock 10 miles east of Santa Barbara). The analysis in Table 9 and Figure 7 shows that mussels on the inside of this clump had more rings per unit length than those on the outside. Mussels from the two samples were then placed in separate plastic colanders which were then lashed together face to face with a plastic divider separating the two resulting compartments. This Page 410 container was then suspended 3 feet below extreme low water at Ellwood Pier. After 4 months growth in this sheltered situation the two groups were again examined. The analyses given in Tables 10, 11, and 12 show that: a) Growth rates of the two groups did not differ from each other. b) An apparent “basal” frequency of check ring formation was established (i. e., rings within new growth) which was the same for both groups (but differed from the previous frequency established at Carpinteria Reef). c) This new frequency of ring formation (sheltered position) was much lower than that of either of the original groups (exposed position). A further experiment at Ellwood Pier designed to com- pare check ring frequency throughout the intertidal range was established by shaving down a series of large mussel clumps growing on the pier pilings until a single layer of Table Check ring comparison between two groups of mussels growing inside a plastic colander placed below low water at Ellwood Pier THE VELIGER Vol. 12; No. 4 mussels remained attached to each piling. This layer ex- tended from the top to the bottom of the removed clumps (approximately 6 feet or 1.9m). The mussels comprising this layer were then allowed to grow for 5 months (February to July, 1966). A comparison was then made between the frequency of rings laid down by the mussels when they were confined to the insides of these clumps (before I had removed the outer mussels) and those laid down after they had been exposed. Results indicate that, during the period of exposure, rings devel- oped at a lower frequency per unit length than previous- ly. Mussels higher up the pilings showed higher frequen- cies than those lower down (both before and after being exposed) (Tables 13, 14, 15). Since mussels from the highest intertidal positions have the lowest growth rates (Harcer, 1967) it seems reasonable to assume that they are developing in positions in which “disturbance” fac- tors (exposure, solar radiation, etc) act with greater intensity and frequency than they would on subtidal 11 Members of the first group were originally growing on the outside of a clump of mussels at Carpinteria Reef, while those of the second group were inside that same clump. The independent variable is growth increment (in centimeters) and the dependent variable is number of check rings within the new growth. 8 A oR Sur 38 i] ae Group Regression Equation wa sh 3 A a 1. Mussels from 44 Y=1.72+3.53X 0.86N.S 3.485 3.63N.S. outside clump 2. Mussels from 38 Y= 1.264 3.92X 3.222 inside clump Table 12 Comparison of the frequency of check rings laid down by Mytilus californianus when growing outside a clump of mussels at Carpinteria Reef with that frequency shown by the same mussels growing within a colander suspended below low water at Ellwood Pier The independent variable is shell length of the first group and length of new growth for the second (in centimeters). The dependent variable is number of check rings. ae Group Eu 7) 1 Mussels outside 64 clump Carpinteria . 2. Mussels growing 44 in colander at Ellwood Pier 3 a e+ Il Regression Equation pd =-2.050+7.047X 2.395*** Y= 1.172+43.528X Vol. 12; No. 4 THE VELIGER Page 411 Table 13 Comparison of the frequency of check rings laid down by Mytilus californianus when growing inside clumps at Ellwood Pier with that frequency shown by the same mussels growing freely on the outside of those clumps The independent variable is shell length for the first group and length of new growth for the second group (in centimeters). The dependent variable is number of check rings. Group 1. Original growth 240 within clumps 2. Final “free” growth 240 outside clumps Regression Equation Y=8.61+4.65X 1,476 2.972 1,476 Adjusted Means at n vo Bp wn x<— 14:09*** 21:97 205.73*** Y=1.7543.02X 10.42 Table 14 Comparison of the frequency of check rings laid down by Mytilus californianus when growing inside mussel clumps high up in the intertidal zone: (Top of mussel clumps at Ellwood Pier, two samples), with that frequency shown by mussels growing low in the intertidal (Inside bottom of mussel clumps at Ellwood Pier, three samples) The independent variable is shell length and the dependent variable is the number of check rings. #19 & 2 g 2 = Be BES mR Group Regression Equation nw g S v te 1. Top Pile 27 53 Y=3.2+6.7X 2505 33.468 IS) fe pdaratas 2. Top Pile 26 51 Y=1.5+6.8X 32.217 3. Bottom Pile 27 42 Y=9.8+3.9X 27.452 4. Bottom Pile 26 62 Y=7.9+4.7X 28.960 5. Bottom Pile 31 32 WS IIa FSep.< 27.393 F Individual D. E Test on B 1,230 1.2./3.4.5 45.99*** Individual D. F. Tests on Adjusted Means 1.2./3.4.5 50.55*** mussels. Further to this, a positive correlation may be said to exist between high check ring frequencies and the action of any factor tending to disturb and inhibit growth, i. e., such as found in mussels growing on exposed shores, high up in the intertidal, or in the center of clumps. Mussels in such situations show much higher check ring frequencies than those taken from quiet areas (Ellwood Pier), low positions within the intertidal or on the outside of mussel clumps. It would seem that 3 separate factors are involved in the formation of check rings on Mytilus californianus: 1. There is some inherent ring-laying pattern which oper- ates even in extreme shelter. 2. A mussel growing freely on the outside of a clump may increase its frequency of ring formation in response to periodic disturbances such as heavy waves, unduly low tides, hot weather, etc. 3. Perhaps a mussel confined within a clump, and there- fore growing extremely slowly (Harcer, 1967), may occasionally experience “favorable” periods in which it is able to grow a little. Such a period might be established by movement of the mussel clump by wave action, so allowing a particular mussel within the clump to be relieved of pressure imposed on it by its neighbors for a short time. Subsequent growth would then give rise to an interval between rings. In this case the rings themselves Page 412 THE VELIGER Vol. 12; No. 4 60 50 40 30 a i 0.2 0.3 0.4 0.5 1.0 10.0 AA a a Wave Force (kg — cm/cm?) Adjusted Mean Check Rings Figure 8 Log log plot of wave force against the mean number of check rings on Mytilus californianus shells (adjusted to a shell length of 5 cm) The © represents the mean ring frequency for a sample of mussels taken from the outer pilings of a pier at Cayucos Beach, San Luis Obispo County, California. The [_] represents the mean check ring frequency for a sample taken from a mid tide rock platform at Monterey Peninsula, Monterey County, California. Both these points have been projected onto a line connecting the points indicating check ring frequency obtained from mussels growing at known wave impact values. The bar representing variation of check rings is proportional to twice the standard error of the mean (on each side). 1. Stearns Wharf 2. outside end of Ellwood Pier 3. Ellwood Shore 4. Goleta Point The line has been eye-fitted to the points would probably be established during the time in which longitudinal growth was prevented. In this connection it should be noted that large mussel clumps, attached to Ellwood Pier pilings, move visibly as waves thrust against them; intermittent movement of this kind might allow streams of water to pass through the clumps at some times, but prevent this flow at others. At least two causal mechanisms seem to be responsible for high frequency ring formation: increased wave im- pact etc (such as would be experienced by a mussel on the outside of a clump) is one such process; the other seems to be instigated as the result of confinement of animals and the consequent uncertain growth within the matrix of a clump. Such a mussel, so placed within the clump, may experience little growth at infrequent inter- vals (with each favorable interval providing the small space between the previous ring and that established when conditions favoring elongation are terminated). Mussels establish rings in response to both factors, but it is possible to distinguish individuals which have developed inside a clump at a glance from those develop- ing on the exterior. The projecting ridges of the rings in the case of the former group tend to be sharply defined, inverted V’s, in cross section, whereas the latter group yield rings that tend to resemble inverted U’s, in cross section. Adjusted Mean Check Rings 20.30 40 .50 aa © @ A Wave Force (kg — cm/cm?) Figure 9 Log log plot of wave force against mean number of check rings on Mytilus edulis shells (adjusted to a shell length of 5 cm) The bar representing check ring variation is proportional to twice the standard error (on each side). Station 1 is a submerged electrode cable at Ellwood Pier, 2 is Stearns Wharf, 3 is outside end of Ellwood Pier, 4 the outer end of Cayucos Pier and 5 the inner region (surf zone) of Cayucos Pier, San Louis Obispo County, California. The exposure rating for the outer end of Cayucos Pier (Point A) was obtained from the Mytilus californianus exposure plot (Figure 8). The exposure value for the point labeled “inner end Cayucos (Point 5) was obtained by doubling the exposure value for the outer end of this same pier, since the inner regions of Ellwood Pier are about twice as exposed as the outer regions The straight line was fitted by eye to the points Vol. 12; No. 4 THE VELIGER Page 413 Table 15 Comparison of the frequency of check rings laid down by Mytilus californianus when growing freely high up in the intertidal one (outside top of mussel clumps at Ellwood Pier, two samples), with that frequency shown by mussels growing low in the intertidal on the outside of mussel clumps at Ellwood Pier (Three samples) The independent variable is growth increment (from February 1966 to 22 June 1966) measured in centimeters and the dependent vari- able is number of check rings. 1 © 2 be =) N 5 q Sh A 395— we Group Regression Equation ) oo || a Lax 1. Top Pile 26 51 Y=2.942.5X 3.73N.S. 6.018 Wea heretes 2. Top Pile 27 53 NYG IP 2A axe 6.357 3. Bottom Pile 26 62 Y=2.342.7% 5.739 4. Bottom Pile 27. 42 Wess ipa 4.496 5. Bottom Pile 31 32 Y=1.04+3.5x 5.336 F Individual D. F. Tests on Adjusted Means 1,230 1.2./3.4.5 23.0 2a It seemed possible that the number of rings per unit shell length could be used as an indication of the amount of harassment mussels had been exposed to during their growth, providing that consideration was lent only to mussels from similar positions within the clumps. The following observations lend further weight to this hypo- thesis. If mussels are taken from the outside of the clumps from a fixed intertidal level, a correlation can be estab- lished between the wave impact value (measured as re- ported) to which they have been exposed and the fre- quency of check rings per 5 cm individual (Figures 8, 9). Such a relationship indicates that the check rings can be used to estimate exposure at a particular place or, more important, to provide an objective method for comparing the exposure between geographical locations. A log log scale was used to plot ring frequency against wave im- pact value in Figures 8 and 9 because, as shown, the points then fell on a straight line. As mentioned previously, a lower limit was found to exist for the frequency of check rings a mussel may lay down, and it would seem that an upper limit might also exist. This would be imposed by the width of the rings themselves, i. e., only a fixed number could exist between two points (if one assumes a minimum thickness for a ring). To determine whether the frequency of check rings on mussels can be used to estimate the wave impact experienced by a particular region of shore line, I have plotted in Figure 8 two points representing check ring frequencies obtained from samples of mussels taken from two places where I had not previously obtained wave impact values. The locations were: 1. The outer pilings of a pier belonging to the Standard Oil Company at Cayucos Beach, San Luis Obispo County, California. 2. An intertidal rock platform at Monterey Peninsula, California. The first point, when projected onto the line connecting the points indicating check ring frequency obtained from mussel populations at known wave impact values, indi- cates that this pier, located on a section of unprotected coast line, experiences far greater exposure than that experienced by Ellwood Pier. The second point, I think, probably represents the max- imum frequency of growth rings which can occur on a 5 cm mussel growing on the outside of a clump in ex- posed conditions. By this I mean that, even if mussels were grown in areas which received twice the wave shock experienced by the Monterey mussels, they would be physically incapable of laying down many more rings. In both cases the check ring frequency yields values for the exposure which these populations of mussels experi- ence which is matched by subjective estimates. A similar relationship between exposure and shell ring frequency exists for Mytilus edulis (Figure 9), although this is far less clear than the M. californianus example. Although Barker (1964) has suggested that a positive correlation exists between mean annual temperature and the thickness of growth layers in 3 species of bivalves, Mercenaria mercenaria, Mactra solidissima and Anadara Page 414 ovalis, his data do not exclude the possibility that turbu- lence or wave impact have played some part. However, if this correlation reflects the action of temperature as a causative modifying factor in the formation of growth layers then one might expect that mussels growing in colder waters would have more check rings than those growing in warmer waters, all other things being equal. SUMMARY anp CONCLUSIONS The wave impact measuring device described provides the intertidal ecologist with a simple method of estimat- ing wave impact at various places. A biological recorder in the form of mussel check ring frequency may also be used where 2 or 3 comparisons are to be made within one particular area. Since several factors are known to affect the frequency of ring production, i.e., height on shore, position within mussel clump, etc, great care must be used when selecting the samples for analysis to ensure that they are taken from comparable positions. I regard a sample of around 50 individuals to be the minimum necessary to establish the mean check ring frequency for any one place. Furthermore, all sizes of mussels directly exposed to wave impact should be equally represented within this sample. I have indicated that several trends in the morpholog- ical characteristics of sea mussels can be linked with changes in wave impact. In a later paper I will show that an understanding of these trends was important in investigating the nature of the competitive interaction between Mytilus edulis and M. californianus on the coasts of Southern California. THE VELIGER Vol. 12; No. 4 ACKNOWLEDGMENTS This work forms part of a Ph. D. dissertation presented at the University of California at Santa Barbara. I wish to thank Dr. J. H. Connel, Dr. D. E. Landerberger and Dr. J. Stimson for considerable advice and support. I wish also to thank the Signal Oil and Gas Company for making their premises at Ellwood available for ecological re- search. LITERATURE CITED BALLANTINE, WILLIAM 1961. _A biologically defined exposure scale for the comparative description of rocky shores. Field Studies 1 (3): 1-19 Barker, RicHarp M. 1964. Microtextural variation in pelecypod shells. logia 2: 69 - 86 Bascom, WILLARD 1964. | Waves and beaches, the dynamics of the ocean surface. Anchor Books, Doubleday « Co., Inc. Garden City, N. Y. 267 pp. E1rion Jones, W. & ANDREAS DEMETROPOULOS 1965. A quantitative approach to the exposure problem. Br. phycol. Bull. 2 (6): 516-517 Harcer, JoHN R. E. 1967. Population studies on Mytilus communities. dissertation, Univ. Calif. at Santa Barbara Li, Jerome C. R. 1964. Statistical inference (I). Arbor, Mich., 658 pp. Moore, Hitary Brooke 1935. The biology of Balanus balanoides. Part IV - Relation to environmental factors. Journ. Marine Biol. Assoc. U. K. 20: 279 - 307 SouTHWappD, A. J. & J. H. Orton 1954. The effects of wave action on the distribution and numbers of the commoner plants and animals living on the Plymouth breakwater. Journ. Marine Biol. Assoc. U.K. 33: 1-19 Malaco- Ph. D. Edwards Bros., Inc., Ann Vol. 12; No. 4 PERVEWIGER Page 415 Supplementary Comments on Deep Water Volutidae from the South China Sea and South Africa BY HARALD A. REHDER Division of Mollusks, Smithsonian Institution, Washington, D. C. 20560 (Plate 61) ADDITIONAL MATERIAL and new information kindly fur- nished me by correspondents have impelled me to publish this paper as a supplement to two earlier papers of mine (ReHveER, 1967; 1969) dealing with deep-water members of the family Volutidae from the South China Sea and South Africa. For cooperation in making this contribution possible I thank the following individuals: Mr. & Mrs. Francis S. Harmon of New York City, Mr. William E. Old of the American Museum of Natural History, Mr. John E. duPont, Director of the Delaware Museum of Natural History, and Mr. Clifton S. Weaver of Honolulu, Hawaii. As in my earlier papers I have used the initials DMNH for the Delaware Museum of Natural History and USNM for United States National Museum (now more properly known as the National Museum of Natural History). Sigaluta pratasensis REHDER, 1967 (Plate 61, Figure 2) 1967. Sigaluta pratasensis REHDER, Pacific Science 21: 182; figs. 1 - 4 The receipt for examination of a large example of this species has induced me to place a note concerning it on record. This specimen was obtained by Mr. and Mrs. Francis S. Harmon from a fisherman in Kaohsiung, Tai- wan, who is said to have obtained it from moderately deep water southwest of Taiwan. It was collected, therefore, somewhere in the South China Sea, probably between Taiwan and the Pratas Reef, which is the type locality of the species. The specimen, now in the collection of Mr. and Mrs. Francis S. Harmon, consists of 44 whorls and has the fol- lowing measurements: length 103.5mm, width 53 mm, length of aperture 73.5 mm. The surface is dull, not glossy as in the young specimens on which the original descrip- tion was based, and shows considerable etching by marine organisms (probably cleaned off by the collector). The color of the shell has a more grayish tone than in the holotype and paratype, being a light grayish yellowish brown (no. 79) to brownish pink (no. 33) (ISCC-NBS color names, KELLY & Jupp, 1965). The columella is brownish with two spirally ascending plaits which are of a pale pinkish white color. It is hoped that further examples of this species, which we now know reaches a length of at least 4 inches, will be found in the area between Taiwan, South China and the northern Philippines, and that the fishermen may be encouraged to preserve the soft parts so that its anatomy may be studied. Fuswoluta capensis (THIELE, 1925) (Plate 61, Figures 4, 6) 1925. Glypteuthria (?) capensis THEE, Wiss. Ergebn. deutsch. Tiefsee-Exp. “Valdivia”, 1898-99, 17 (2): 179; plt. 19, fig. 27 1959. Fusivoluta capensis (THIELE), BARNARD, Ann. South Afr. Mus. 45: 30 - 31 (in part) I have been able to examine two color transparencies of the type of THIELE’s species, taken by Mr. Hans Lehman of Black Star. From these slides, which are reproduced in black and white on Plate 61, Figures 4 and 6, I have con- structed a description of this species to supplement the brief four-line description given by THIELE. Description: Shell small, ivory-white in color, obovately fusiform in shape, suture deeply impressed, almost chan- neled, whorls of spire rather flattened, body whorl slightly convex. Protoconch of about 2+ (?) nuclear whorls, smooth, bulbous. Postnuclear whorls strongly axially ribbed, the ribs retractively curved, about 22 - 23 on last whorl. The ribs are crossed by fine spiral cords, about 10 in number on penultimate whorl, the subsutural cord pro- nounced, giving the suture an almost channeled appear- ance. Aperture narrowly ovate, the anterior canal rather broad at the slightly constricted base. Measurements (from THIELE): Height, 11 mm; width, 4.5 mm. Remarks: In my paper on South African deepwater vo- lutes (REHDER, 1969, p. 205) I followed BaRNarp (1959, p. 30) in synonymizing Glypeuthria capensis TOMLIN Page 416 THE VELIGER Vol. 12; No. 4 (1932, p. 165) with THreLe’s species. An examination of a photograph of the type of THIELE’s species, however, leads me to believe that TomMLin’s species, renamed sculp- turata Tomun (1945, p. 135), should, at least for the time being, be considered a distinct species. From Fusivoluta sculpturata (Tomun) FE capensis dif- fers notably in its size. The type, consisting of 6 whorls (THIELE says 53 whorls, but the photograph shows 6 or even slightly more whorls), measures only 11 mm, while the type of FE sculpturata, which ToMuIn states consisted of 7 whorls (though here again the photograph seems to show a shell of 64 whorls), measures 29 mm, almost 3 times as large; other specimens of F sculpturata that are even somewhat larger have only 6 to 64 whorls. Thus, specimens of F sculpturata with approximately the same number of whorls possessed by the type of F capensis are almost 3 times as large as the latter. The spire of F cap- ensis THIELE is not as slender as in F sculpturata, the whorls appear to be channeled, the axial ribs are more numerous (22 - 23 on the last whorl, instead of 16 - 18 as in EF sculpturata), the spiral cords are subequal rather than unequal, and there is a strong subsutural cord present instead of the series of 5 fine cords below the suture. Fusivoluta sculpturata (TOMLIN, 1945) (Plate 61, Figures 1, 3, and 5) 1932. Glypteuthria capensis Tomuin, Ann. South Afr. Mus. 30: 165; fig. 6 (not THIELE, 1925) 1945. Glypteuthria sculpturata ToMLIN, Journ. Conch. 22: 135 1957. Fusivoluta capensis (THIELE), BARNARD, Journ. Conch. 24: 210 (not Tuer, 1925) 1959. Fusivoluta capensis (THIELE), BARNARD, Ann. South Afr. Mus. 45: 30 - 31 (in part) 1965. Fusivoluta capensis (THIELE), WEAVER, Hawai. Shell News 13 (3): 7; figs. 5, 6 1969. Fusivoluta capensis (TuHtELe), REHDER, The Veliger 11: 205; plt. 42, fig. 32 (in part) Description: Shell elongate, obovate, with rather attenu- ate spire, grayish white, whorls moderately convex, ap- pressed at suture. Protoconch consisting of probably 2 (corroded) nuclear whorls; postnuclear whorls slightly shouldered and gently convex, bearing arcuate axial ribs numbering 16 to 18 on last whorl. The ribs are crossed by spiral cords sometimes varying in strength and crowded, or subequal and more or less separated; between the slight shoulder and the appressed suture the spiral cords are noticeably finer. Aperture ovate, last whorl usually not constricted at the short broad anterior canal. Operculum ovate-unguiculate, nucleus terminal. Measurements (in mm) Height Width Holotype (from Tomtin) 29.0 12.0 S.A. M. (from Barnarp, 1959) 38.0 15.0 DMNH 10668 30.0 13.0 DMNH 10123 742) ff 11.9 Remarks: The differences between this species and F capensis THIELE have already been noted above. I am as- signing with some doubt the specimens in the Delaware Museum of Natural History, which I have examined, to ToMLIn’s species, which I know only from the original figure and the descriptions by Tomuin and Barnarp (1959, p. 31). The outer lip on both the Delaware specimens is imperfect, and they seem to have suffered injury of some kind; neither shows the evenly and broadly arcuate out- line and lack of constriction at the anterior canal shown in ToMLin’s original figure. In sculptural characters, however, the specimens in the Delaware Museum of Natural History agree with Tom- LIN’s type, with the exception that the nature of the spiral cords on the body whorl is variable; in one specimen (DM NH 10123) the cords are crowded and rather unequal as in the holotype; in the other (DMNH 10668) the cords are distant and equal. However, until further material is available and the types can be reexamined, it is better to unite all these specimens under one name. LITERATURE CITED BarNARD, KEPPEL Harcourt 1957. Glypteuthria capensis: a generic correction. Conch. 24: 210 1959. Contributions to the knowledge of South African marine Mollusca, Part II :Gastropoda: Prosobranchiata: Rhachiglossa. Ann. South Afric. Mus. 45 (1): 1-237; 52 figs. (June) Ketty, KENNETH Low & DEANE BREWSTER JUDD 1965. The ISCC-NBS method of designating colors and a dictionary of color names. Nat. Bur. Standards Circ. 553 (reprint ed.) v+158 pp. ISCC-NBS color-name charts illus- trated with centroid colors (Suppl. to NBS Circ. 553) REHDER, HarALD ALFRED 1967. A new genus and two new species in the families Voluti- dae and Turbinellidae (Mollusca: Gastropoda) from the West- ern Pacific. Pacif. Sci. 21: 182 - 187; 11 figs. 1969. Volutocorbis and Fusivoluta, two genera of deepwater Volutidae from South Africa. The Veliger 11 (3): 200 to 209; plts. 40 - 43 (1 January 1969) THIELE, JOHANNES 1925. | Gastropoda der deutschen Tiefsee-Expedition. II. Teil. Wiss. Ergebn. Deutsch. Tiefsee-Exped. “Valdivia,’ 1898-1899. 17 (2): 35-382; plts. 13-46; 31 text figs. ToMLIN, JoHN Reap LE BRocKTON : 1932. Reports of the marine Mollusca in the collection of the South African Museum. VI - VIII. Ann. South. Afr. Mus. 30: 157 - 169; 10 text figs. 1945. ‘Two South African species renamed. 22: 135 WEAVER, CLIFTON STOKES 1965. _ Volute problems. 8 text figs. Journ. Journ. Conch. Hawaiian Shell News 13 (3): 7; lo THE VELIGER, Vol. 12, No. 4 [REHDER] Plate 61 Figure 1 X a —_ Figure 3 Figure 4 Figure 5 Figure 6 Figures, 1 and 3: Fusivoluta sculpturata (ToMLIN) DMNH 10668 (xX 2-) Figure 2: Sigaluta pratasensis REHDER ES. Harmon Coll. (X 1-) Figures 4 and 6: Fusivoluta capensis (THIELE) Holotype, Zool. Mus. Berlin (X 6) Figure 5: Fuswoluta sculpturata (Tomuin) DMNH 10123 (X ‘1.5-) Vol. 12; No. 4 THE VELIGER Page 417 Uptake of Sea Water into the Fluid Spaces of the Prosobranch Gastropod, Acmaea scutum ' BY H. H. WEBBER’ Department of Zoology, University of British Columbia, Vancouver 8, Canada INTRODUCTION THE CIRCULATORY SYSTEM of most gastropod mollusks functions in part as a hydrostatic skeleton. In the past it was believed that gastropods could incorporate sea water into the blood space to facilitate the expansion of the foot. However, the current view is that, with one excep- tion (the family Naticidae) a constant blood volume in the circulatory system is sufficient to cause the expansion of the foot of gastropods (Morris, 1950; CHapMaN, 1958; Brown & TuRNER, 1962; Brown, 1964; BERNARD, 1968; RusseELt-HunNTER & ApLey, 1969). For the Nati- cidae Morris, op. cit., BERNARD, op. cit., and RUSSELL- HunTER & APLEy, op. cit., have described a system of aquiferous ducts that are separate from the blood system and fill with sea water during foot expansion. This study shows that the limpet Acmaea scutum RaTHKE, 1833, which does not use the hydrostatic skele- ton to expand the foot in the manner of most gastropods, does however, demonstrate large changes in total volume. Evidence is presented showing that this change in vol- ume results in part from the incorporation of large quan- tities of sea water directly into the blood space. MATERIAL ann METHODS Most limpets used were collected from Jordon River, British Columbia. Laboratory maintenance is described in WEBBER & DEHNEL (1968). Acmaea scutum used in methylene blue experiments were collected at Stillwater Cove, Monterey, California. 1 This study was aided by grants from the National Research Council of Canada and the National Science Foundation of the United States to Dr. Paul A. Dehnel. I thank Dr. J. H. Phillips, Director of Hopkins Marine Station for generously providing equipment and facilities for part of this study. 2 Present address: Department of Biology, Wake Forest Univer- sity, Winston-Salem, North Carolina 27109 Measurements of Volume Change Animals were maintained in sea water for 24 hours before use. The method of volume measurements was as follows. The animal was taken from the experimental salinity and the foot was compressed gently with absorbent tissue. Volume was determined by removing the limpet from sea water, compressing the foot gently with absor- bent tissue, and weighing the volume of sea water dis- placed by the animal. The method was accurate to +0.1 ml. ‘To measure changes in volume, limpets were returned to sea water with the dorsal surface of the shell against substrate so the animal could not attach with the foot. Animals were maintained in this position for the desired time period. The volume of the animal was again deter- mined after gently shaking to remove water from the nuchal cavity and space between the foot and shell. The increase in volume was determined by subtraction. The volume of the soft body parts alone was determined by estimating the volume of the shell separately and sub- tracting this value from the total volume. Blood Amaranth Samples Samples for the determination of blood amaranth values were taken from the visceral sinus through an incision in the foot muscle. Approximately 100m liter samples were measured colorimetrically without dilution at 520 mpl, using sea water as a blank. Blood Inulin Samples Blood samples for the measurement of inulin were taken from an incision through the foot into the visceral sinus. Fifty microliter aliquots of blood were assayed for inulin by the anthrone method of Younc & Ratsz (1952). RESULTS When Acmaea scutum is removed from the substrate and placed in sea water upside down so it cannot right itself, Page 418 THE VELIGER Vol. 12; No. 4 over a period of time the soft parts of the limpet appear to swell. The results recorded below document and char- acterize this change in size. In measuring the volume increase, it was important that limpets at the start of an experiment had the same relative water content. Before measuring the starting volume the animal was blotted with absorbent tissue to remove excess water. A test using regression slopes (Table 1) showed that all limpets had the same relative water content when the starting volume was measured. Table 1 Regression equations of initial water content plotted against dry weight for Acmaea scutum used in experiments on uptake of water at constant salinity. The p value indicates the probability level at which the regression slope is significant average water regression equation P content NC = eS SP Ds. 0.01 83.7% (n = 60) Y = 0.81 + 4.32X 0.01 Y = 0.68 + 4.50X 0.01 The change in volume with time is given in Table 2. The volume of the animals increased even though the salinity of the water was constant. By 6-12 hours in this inverted position, limpets increased the volume of the soft parts by approximately 100%. The variation indi- cated that only large differences could be considered sig- nificant. The purpose of the experiment was to demon- strate that Acmaea scutum could show an increase in volume of the soft body parts when held at a constant salinity. Nature of the Volume Change The blood and urine of Acmaea scutum are essentially sea water. The blood and urine concentrations of the major ions (Na*, Cl, Mg**, and Ca‘) are the same as the corresponding concentrations in sea water (WEBBER & DEHNEL, 1968). Ion values for blood and urine samples taken at all stages during increase in volume remained constant, i. e., were the same as sea water. The observed increase in volume, then, must have been achieved by taking in both ions and water. Uptake of Amaranth To determine if the water uptake response involved all fluid spaces of the limpet, the red dye amaranth was Table 2 Increase in volume of soft body parts of Acmaea scutum in 100% sea water. Part A is the number of animals of a sample of 10 showing an increase in soft body parts of 5%. Part B is the mean increase in volume (per cent) for those animals showing an increase of 5%. Part C is the blood concentration of amaranth (mg/l) at a concentration of 0.025 mg/l Part A number of animals out of 10 showing increase in volume Time in hours [pe SPO Ge ee ES 2 0. 50, 50 10 Part B means of increase in volume (per cent) Time in hours 14 3 6 12 24 48 70.7 71.7 86.2 98.2 100.3 100.5 Part C Blood concentration of amaranth Time in hours 14 3 6 12 24 48 dye conc. 0.013 0.012 0.012 0.011 0.014 0.010 n 4 7 7 8 7 9 added to the sea water to act as a tracer. Comparison (t-tests) of results of volume changes in sea water with and without amaranth showed the presence of the dye did not significantly (p=0.01) alter the increase in volume. When limpets increased in volume in “amaranth sea water” the dye became distributed throughout the tissues. All parts of the animal “blushed” — including the gill and mantle fringe. After volume changes, the values of amaranth in the blood were determined. There is a relationship between blood amaranth values and volume increase (Table 2). The average volume increase was around 100%, indicat- ing the volume of water taken up was equal to the starting volume of the soft parts. The average blood dye value for these animals (0.012g/) was around $ that of sea water (0.025g/1). It appears the increase in volume of soft parts was facilitated by bulk movement of sea water Vol. 12; No. 4 THE VELIGER Page 419 with the dissolved dye into the fluid spaces of the limpet. The final blood dye concentration (4 that of sea water) would then be due to the diluting effect of the fluid of the starting volume. It is not possible to analyze more critically the relationship between water and dye uptake because (1) the intracellular distribution of amaranth, if any, was not known, and (2) the extent of the blood space at any given time was not known. Amaranth did enter the kidney space as well as the blood space. Animals stimulated to contract after volume increase in amaranth sea water would evacuate urine that was red from the dye. Uptake of Inulin Inulin is generally believed not to enter cells (WHITE et al. 1959), although Scorr et al. (1964) report the ab- sorption of inulin from the proximal tubule of Necturus kidney. To determine if Acmaea scutum could also take up inulin during volume increases limpets were placed in sea water solutions of inulin. Table 3 gives the results. Again limpets increased in volume around 100%. The average blood inulin value was 2.8g/1 compared with 4¢/] in the surrounding sea water. If the starting volume was considered as a water space the doubling of volume by uptake of water and 4¢g/1 inulin would result in a final blood inulin value of 2.0g/1. However, since inulin prob- ably did not penetrate intracellularly, the fluid available for dilution would be less and the observed blood inulin value of 2.8g/1 would be expected. As with amaranth, the inulin data support the hypothesis that the increase in volume occurred by a bulk movement of sea water into the blood space. Table 3 Blood inulin concentration (g/l) after Acmaea scutum had shown an increase in volume of soft body parts by taking up sea water. Each experimental salinity contained an inulin concentration of 4g/I1 average average % increase n inulin conc. n 113.8 30 2.85 29 Mechanism of Volume Increase Histological sectioning showed no pores leading into the blood space. ‘To determine if water was passing into the radula sac or intestine the volume increase was followed in a sea water solution of the vital dye methylene blue. During the volume increase the gut but not the radula sac stained blue. To insure that it was not a case of selective staining, 1 cc of 0.1% methylene blue was injected into the blood space of each of 5 limpets. After 2 hours, the gut and radula sac were ex- amined. Both were equally but lightly stained (2 out of a scale of 4). Moreover, when the radula and radula sac were removed from 5 limpets and stained in vitro in 0.1% methylene blue for 15 minutes, the radula sac was stained (3 out of a scale of 4). These data support the idea that sea water was passed into the gut. No direct evidence is available, however, that sea water passes from the gut into the blood space. DISCUSSION In this study it is shown that the limpet Acmaea scutum was capable of taking large quantities of sea water into both the blood and urine spaces. Limpets could take up a volume of sea water approximately equal to the starting volume of the soft parts. It was not possible to separately measure the extent of the increase of blood and urine spaces. Data using the vital dye methylene blue suggest that sea water passes into the blood space through the gut. This response of Acmaea scutum differs from the in- crease in volume shown by the Naticidae (moonsnails). There, the large volume increase is due to uptake of sea water into “aquiferous ducts” that are separate from the blood space (Morris, 1950; BERNARD, 1968; RussELt- Hunter & ApLey, 1969). In A. scutum the sea water taken in during volume increase, in part at least, mixes directly with the blood. It is difficult to explain how the change of volume of Acmaea scutum is connected to the function of the hydro- static skeletons. Limpets cannot withdraw into their shell, so the uptake of sea water is probably not normally used for foot expansion. These experiments were performed with the limpets turned upside down. However, it is unlikely that the uptake of sea water into the fluid spaces is unique to the animal being in this position. Possibly, sea water uptake is an adaptation to intertidal exposure. The importance of free water in the mantle cavity and pallial groove (extravisceral water) of limpets in decreasing desiccation effects have been shown by SEGAL & DEHNEL (1962). When they removed the extravisceral water from Acmaea limatula CARPENTER, 1864, the limpet showed a more rapid increase in the total osmotic pressure of the blood when desiccated. As well, SHotwett (1950) Page 420 showed that animals having the greatest exposure time have the largest extravisceral water space. In Acmaea scutum the ability to take sea water into the circulatory system could be an important adaptation to desiccation stress in that it results in a larger fluid volume to act as an osmotic buffer. SUMMARY 1. Evidence is presented to show that Acmaea scutum could increase the water content of the soft body parts at a constant salinity. The increase in water content resulted from sea water entering the fluid spaces from the external environment. 2. While taking up sea water from the external environ- ment, the molecules inulin and amaranth could also pass into the blood space from the external sea water when these molecules were dissolved in experimental salinities. 3. Using methylene blue as a tracer, it appears that sea water enters the fluid spaces of the limpet through the gut. LITERATURE CITED BERNARD, E.R. 1968. The aquiferous system of Polinices lewisi (Gastropoda, Prosobranchiata) . Journ. Fish. Res. Brd. Canada 25: 541 - 546 THE VELIGER Vol. 12; No. 4 Brown, A.C. 1964. Blood volumes, blood distribution and sea-water spaces in relation to expansion and retraction of the foot in Bullia (Gastropoda). Journ. Exp. Biol. 41: 837 - 854 Brown, A.C. « L. G. W. TuRNER 1962. | Expansion of the foot in Bullia (Gastropoda) . Na- ture 195: 98 - 99 CHAPMAN, GaRTH 1958. The hydrostatic skeleton in the invertebrates. Biol. Rev. 33: 338 - 371 Morris, Murret C. 1950. Dilation of the foot in Uber (Polinices) strangei (Mol- luscs, class Gastropoda) . Proc. Linn. Soc. New South Wales 75: 70 - 80 RussELL-Hunter, W. D. & M. L. APLEY 1969. Pedal expansion in the naticid snails. II. Labelling ex- periments using inulin. Biol. Bull. 135: 553 - 573 Scott, W. N., D. L. Maune, I. SHEHADEH « A. K. SoLoMON 1964. Inulin and albumin absorption from the proximal tub- ule in Necturus kidney. Science 146: 1588 - 1590 SecaL, Eart & Pau, Aucustus DEHNEL 1962. Osmotic behavior in an intertidal limpet, Acmaea lima- tula. Biol. Bull. 122 (3) : 417 - 430; 5 figs.; 1 table SHOTWELL, JESSE ARNOLD 1950. Distribution of volume and relative linear measurement changes in Acmaea, the limpet. Ecology 31: 51 - 61 WEBBER, HERBERT H. « PauL Aucustus DEHNEL 1968. Ion balance in the prosobranch gastropod Acmaea scutum. Comp. Biochem. Physiol. 25: 49 - 64 Wulire, A., P Hanpier & E. L. Smiru 1959. _— Principles of Biochemistry. 1106 pp. Youn, M. « L. Ratsz 1952. Anthrone procedure for determination of inulin in bio- logical fluids. Proc. Soc. Exp. Biol. Med. 80: 771 - 774 McGraw-Hill, New York, Vol. 12; No. 4 THE VELIGER Page 421 Notes on the Deep Water Calliostomas of the Panamic Province with Descriptions of Six New Species JAMES H. McLEAN Los Angeles County Museum of Natural History goo Exposition Boulevard, Los Angeles, California 90007 (Plate 62) Tue PaNnamic specigs of the trochid genus Calliostoma may be grouped by depth of occurrence: one group of species occurs at low tide in rocky sublittoral zones, and on shallow offshore bottoms to depths of 20 fathoms, while another group of species is dredged only at depths of 30 fathoms and deeper. Only 2 deep water species have previously been known in the Panamic province. A third species known from the Peruvian province is added to the list and 6 new species are here described, based on a relatively small amount of material. In comparison to the numerous species of Calliostoma in the tropical west- ern Atlantic (CLENcH & TurRNER, 1960), the number of species in the eastern Pacific is relatively sparse. The comparative lack of extensive deep dredging in the east- ern Pacific may account for the paucity of known species. A more nearly equivalent number of species may even- tually be known. Sources of the new species described herein are as fol- lows: ‘The Templeton Crocker Expedition of 1936 pro- duced one of the species. Three result from the Allan Hancock Pacific Expeditions and are part of the Allan Hancock Pacific Foundation Collection, now on loan to the Los Angeles County Museum of Natural History. Two result from recent dredging at Santa Cruz Island, Gala- pagos Islands, by André and Jacqueline DeRoy, the orig- inal specimens of which were kindly forwarded to me by Mr. Anthony D’Attilio of the San Diego Natural History Museum. I am grateful to the institutions and collectors mentioned for the opportunity to work with this material. Abbreviations for institutions cited in the text are as follows: AHF Allan Hancock Foundation (collection on loan to LACM) CAS California Academy of Sciences, San Fran- cisco LACM Los Angeles County Museum of Natural History SDNHM_ San Diego Natural History Museum SSB S. Stillman Berry Collection, Redlands, California SU Stanford University Collection, Stanford, California USNM United States National Museum No attempt has been made at this time to assign any of the eastern Pacific species of Calliostoma to subgenera. CLENCH & TuRNER (1960) recognized three subgeneric groups based on radular and jaw morphology. In estab- lishing new subgeneric taxa they failed to consider other generic units in the subfamily Calliostomatinae, many of which have been used in a full generic sense by workers in other parts of the world. My own radular studies on the easern Pacific species are in progress. Three of the 8 species treated here are recorded from San Jaime Bank off Cape San Lucas and a 4" from the Gorda Banks in the same vicinity. Further dredging at these banks should prove productive. Calliostoma iridium Daut, 1896 (Plate 62, Figure 1) Calliostoma iridium Dat, 1896, p. 7; — 1902 p. 552, plt. 39, fig. 3; — 1908, p. 348, plt. 19, fig. 5 Diagnosis: Whorls flat sided, spiral cording consisting of 2 strong, beaded cords at the periphery and one below the suture, the area between these nearly smooth on the early whorls but with 7 finely beaded cords increasing in promi- nence on later whorls; base imperforate, sculptured with numerous, weakly beaded spiral threads. Color, yellowish pink with radiating flammules, with bronze pink irides- Page 422 cence strongest on the early whorls. Height, 21.5, diameter, 19.2 mm (holotype). Type Material: Holotype, USNM 122957; 7 paratypes, USNM 122957a; 1 paratype, SSB 16962. Type locality: USFC station 3387, Gulf of Panama, 127 fms. Distribution: Gulf of Panama. In addition to the type lot consisting of 9 specimens, there is 1 specimen, USNM 122956, USFC sta. 3391, Gulf of Panama, 153 fms. Discussion: Calliostoma iridium may be distinguished from other eastern Pacific species by the near absence of sculpture between the subsutural and the 2 peripheral cords on the early whorls. Calliostoma nepheloide DALL, 1913 (Plate 62, Figures 2 to 5) Calliostoma nepheloide Daur, 1913, p. 592; — 1925, p. 9, pit. 24, figs. 2-3; — Keen, 1958, p. 256, fig. 46 (upper figure only, copy DALL) ; — Par- KER, 1964, p. 151 Diagnosis: Whorls flat sided, final whorl slightly con- vex, spiral cording consisting of a strong, projecting, beaded peripheral cord and about 12 fine beaded cords between it and the suture on the final whorl. Base imper- forate, defined by a broad, unbeaded cord below the peri- pheral cord, base with about 18 weakly beaded cords, more broadly spaced near the columella. Color, olive green with darker flammules, basal cords with alternating light and dark markings. Height, 25, diameter, 22 mm (holotype). Type Material: Holotype, USNM 96637. Type locali- ty: USFC sta. 2804, Panama Bay, 47 fms. The holotype has the lip broken back about 4 of a whorl. Dati’s 1925 illustration reconstructed the position of the lip. Distribution: Point Abreojos to Cape San Lucas, Baja California; Mazatlan, Sinaloa, Mexico to Gulf of Pana- ma. Records: AHF 1711-49, 30 mi. S. Pt. Abreojos, Baja California, 52 fms.; AHF 618-37, San Jaime Bank, off Cape San Lucas, 75 fms. (Plate 62, Figure 5) ; off Mazat- lan, Sinaloa, Mexico, 88 - 92 fms. (ParKER, 1964) ; AHF 273-34, Tenacatita Bay, Jalisco, Mexico, 45 fms.; SDN HM 39799, off Manzanillo, Colima, Mexico, 52 fms. (Plate 62, Figures 3, 4); LACM, Gulf of Tehuantepec, Chiapas, Mexico, leg. D. Shasky, 45 fms.; CAS 17986, Gulf of Chirqui, Panama, 35-40 fms. The species is as yet unknown from the Gulf of California. Remarks: The 2 immature specimens from San Jaime Bank off Cape San Lucas differ from the others in having THE VELIGER Vol. 12; No. 4 the immediate subsutural cord more strongly beaded than the others. This is the only significant feature of varia- tion in the material examined. The olive coloration of the species is distinctive. Calliostoma fonku (PxHiuiprt, 1860) (Plate 62, Figures 6, 7) Trochus fonkit Puruiprt, 1860, p. 185, plt. 7, fig. 22 Calliostoma fonkii (Putt.) — Pirssry, 1889, vol. 11, p. 371, plt. 57, fig. 48 (copy Puitiprr). — DALL, 1909, p. 240. Diagnosis: Whorls flat sided, final whorl slightly con- vex; spiral cording consisting of a smooth peripheral cord, the lower part of which is covered by succeeding whorls, and 3 prominent cords per whorl, the 2 uppermost coarse- ly beaded, narrow raised ridges between major cords ap- pearing on the final whorls; base imperforate, with up to 11 evenly spaced unbeaded cords. Color tan, with darker cording. Height, 17.5, diameter, 16.2 mm (AHF 802-38). Type Material: Holotype, not located. Type locality uncertain: “Between Chiloé and the mainland of Peru” (Pitssry, 1889). Distribution: Galapagos Islands; Peru south to Chiloé Island, Chile (43° S). Records: AHF 802-38, NW of Charles (Santa Maria) Island, Galapagos Islands, Ecua- dor (1°09’ S, 90°35’ W), 250 fms. (Plate 62, Figure 6) ; AHF 371-35, Independencia Bay, Peru (14°15’S), 5 fms. (Plate 62, Figure 7). The two specimens here re- ported are believed to be the first specimens known since the original description. Remarks: Although the 2 specimens are from widely separated localities and vastly different depths, no essen- tial points of difference are apparent. The Galapagan specimen is colorless and the nacre is slightly leached, while the smaller Peruvian specimen was live-taken and is tan with brownish ribs. Little can be said of the distribution and occurrence of this species until more material is known. It may perhaps not be a characteristically deep water species, judging at least from its shallow occurrence in Peru. Calliostoma gordanum McLean, spec. nov. (Plate 62, Figures 8 to 10) “Calliostoma nepheloide Datu.” — Kren, 1958, fig. 46 (lower figure only). Diagnosis: Whorls slightly convex, spiral cording con- Vol. 12; No. 4 THE VELIGER Page 423 sisting of 2 peripheral cords with a finer intercalary cord between; 7-8 strong beaded cords between sutures on final whorl, secondary threading between cords on final whorl; base imperforate, with 17 - 20 beaded cords. Col- or whitish, with radiating light tan maculations, base un- marked. Height, 19.6, diameter, 20.0 mm (holotype). Description of Holotype: Shell of moderate size for the genus, light, rather fragile. Postnuclear whorls 7, slightly convex. Periphery rounded but defined by 2 somewhat stronger spiral cords with a finer intercalary cord be- tween. Fifth postnuclear whorl with a strongly beaded subsutural cord and 6 thin, raised, unbeaded cords be- tween it and the upper peripheral cord. By the 5" whorl the intermediate cords are finely beaded and fine inter- calary threads have appeared. By the 7" and final whorl the intercalary threads have increased in size and are beaded as are the primary cords. Base imperforate with 17 cords, intercalary threads between the outermost cords, those nearer the columella more broadly spaced and bead- ed in a radiating pattern. Color whitish tan with brownish flammules, aperture iridescent with pink and green, base unmarked. Type Material: Holotype, CAS 13271; 3 paratypes, CAS 13272; 1 paratype, LACM 1268; 1 paratype, USNM 679551; 3 paratypes, SDNHM 40041; 1 paratype, SU 9985. Type locality: Gorda Banks, off southeastern Baja California, CAS locality 17752. According to Dr. Leo G. Hertlein, this station represented 26 hauls made by Croc- ker and Beebe on the Templeton Crocker Expedition of 1936 in the vicinity of the Gorda Banks, approximately 23°02’ N, 109°31’ W, probable depth, 70 fms. Seven spe- cimens, originally identified by A. M. Strong as Callio- stoma nepheloide, were in this lot. Three additional spe- cimens, evidently from the same lot, were found in the Strong collection at the San Diego Museum. Referred Material: One additional lot is known: AHF 531-36, San Francisquito Bay, Baja California (28°26’ N, 112°53’30” W), 10 fms., 2 specimens (Plate 62, Figure 10). The illustrated specimen from this lot is 13 mm in height and has slightly more prominent spiral cording but is otherwise typical. The relatively shallow depth record of 10 fathoms for this lot may be anomalous. Dredging off the tip of Baja California should produce additional material of this species. Discussion: Calliostoma gordanum may be separated from C. nepheloide by its light color, its near absence of spiral markings on the basal cords, and in having 2 rather than 1 major peripheral cords. Calliostoma sanjaimense McLean, spec. nov. (Plate 62, Figure 11) Diagnosis: Whorls flat sided, spiral cording consisting of 2 strong, beaded peripheral cords, a strong subsutural cord, and 5 strongly beaded intermediate cords; base imperforate, with 11 broad, nearly smooth spiral cords. Color yellow brown with light and darker markings par- ticularly on the peripheral cords. Height, 20.0, diameter, 18.4mm (holotype). Description of Holotype: Shell of moderate size, sturdy, flat sided. Postnuclear whorls 7. Periphery angulate, de- fined by 2 prominent beaded cords with a narrow inter- calary cord between. A strong, beaded subsutural cord is prominent on later whorls. On the 3 whorl there are 3 cords of equal strength; other cords arise as intercalary threads that eventually become beaded and assume full size, until in the final whorl there are 5 beaded cords and 4 intercalary threads between the subsutural and the uppermost peripheral cord. Base imperforate, with 17 broad, low cords, interspaces of nearly equal width, the 3 cords close to the columella faintly beaded. Color yellow brown with light and darker maculations especially on the peripheral cords. Type Material: Holotype, LACM-AHF 1269; 2 para- types, LACM-AHF 1270, 1 paratype, USNM 679552. Type Locality: San Jaime Bank, west of Cape San Lucas, Baja California, Mexico, 22°50’30” N, 110°15’ W, 75 fms., Velero III station 618-37, 3 March 1937. The 3 paratypes are all immature, the largest specimen meas- uring 10.3 mm in height. No additional material is known. Discussion: Calliostoma sanjaimense is most closely related to C’. iridium but has a sturdier shell, has strongly beaded cords on the early whorls, which are lacking in C. iridium, and has fewer and more prominent basal cords. The immature paratype specimens show brilliant metallic iridescence of green and yellow on the smooth narrow interspaces between the spiral cords of the early whorls, but this luster has evidently faded in the holotype. Calliostoma veleroae McLEan, spec. nov. (Plate 62, Figure 12) Diagnosis: Whorls concave, spiral cording consisting of a projecting peripheral cord and 6 evenly beaded cords on the last whorl; base imperforate, but with a shallow depression, base with about 18 low cords, beaded near the columella. Color yellowish with brown flammules, basal Page 424 cords with alternating light and dark markings. Height, 15.9, diameter, 17.0 mm (holotype). Description: Shell of moderate size, sturdy, sides of whorls concave, imparting a concave slope to the sides of the shell. Postnuclear whorls 8, periphery sharply angu- late, projecting, actually composed of 3 finely beaded cords, 2 at the edge of the periphery and 1 just above. Strong subsutural cord lacking. There are 3 beaded inter- mediate cords on the 3 whorl, increasing by the addition of intercalary threads that gradually increase in size and become beaded until there are 6 cords and an equal number of intercalary threads on the final whorl. Base slightly convex, imperforate but with a hollow excavation near the columella; base with 18 low spiral cords, the interspaces of nearly equal width; innermost cords faint- ly beaded in a radial pattern of growth. Color yellowish with brown flammules, basal cords with alternating light and dark markings. Type Material: Holotype, LACM-AHF 1271. Type Locality: Three miles south of Isla Ladrones, Pana- ma, 7°49’ N, 82°23’30” W, 54 fms., Velero III station 943-39, 27 March 1939. The holotype, the only known specimen, has a broken lip and a hole in the base of the shell; the color is evidently somewhat faded. Discussion: Calliostoma veleroae stands alone among west American species in having a concave outline and a sharply carinate periphery. It also differs from most of the species discussed here in lacking a relatively strong sub- THE VELIGER Vol. 12; No. 4 sutural cord. A species of somewhat similar proportions in the Caribbean fauna is Calliostoma aurora Daut, 1888, but that species has a smooth, nearly concave base. Calliostoma veleroae is named in honor of the Velero III, the vessel of the late Captain G. Allan Hancock, whose collecting expeditions formed the basis of the rich molluscan material in the Allan Hancock Foundation collection. Calliostoma keenae McLean, spec. nov. (Plate 62, Figures 13 to 16) Diagnosis: Whorls and periphery rounded, spiral cording unbeaded until the 4" whorl, final whorl with numerous raised, finely beaded spiral cords, interspaces of equal width; base imperforate, with about 12 low, weakly beaded cords. Color, drab green or yellow brown with brown flammules. Height, 14.9, diameter, 15.5 mm (holo- type). Description of Holotype: Shell of medium size, whorls markedly convex, base of shell delimited by a thicker spiral rib, postnuclear whorls 7. Sculpture of first to 3" postnuclear whorls consisting of 3 raised cords, a trace of beading appearing on the uppermost cord on the 4% whorl; the middle of the 3 original cords persists as a slightly more prominent cord on all succeeding whorls. Additional cords arise from intercalary threads until, on the final whorl, there are 15 cords between the basal cord and the suture; interspaces are about as wide as the cords and the uppermost cords are the more strongly Explanation of Plate 62 Figure 1: Calliostoma iridium Dat, 1896. Holotype, USNM 122957. Gulf of Panama. Height, 21.5, diameter, 19.2mm. X 1.5 Figure 2: Calliostoma nepheloide Dati, 1913. Holotype, USNM 96637. Panama Bay. Height, 25, diameter, 22 mm. X 1.5 Figures 3 and 4: Calliostoma nepheloide. SODNHM 39799. Man- zanillo, Mexico. Height, 20, diameter, 20 mm. XxX 1.5 Figure 5: Calliostoma nepheloide. AHF 618-37. San Jaime Bank, Mexico. Height, 11.7, diameter, 11.6 mm. xX 15 Figure 6: Calliostoma fonki (Putrpri1, 1860). AHF 802-38. Charles Island, Galapagos. Height, 17.5, diameter, 16.2mm X 2 Figure 7: Calliostoma fonkii. AHF 371-35. Independencia Bay, Peru. Height, 9.1, diameter, 8.0 mm. X 4 Figures 8 and g: Calliostoma gordanum McLean, spec. nov. Holo- type, CAS 13271. Gorda Banks, Mexico. Height, 19.6, diameter, 20.0 mm. XK 15 Figure 10: Calliostoma gordanum. AHF 531-36. San Francisquito Bay, Mexico. Height, 13.2, diameter, 13.3 mm. X 1.5 Figure 11: Calliostoma sanjaimense McLEan, spec. nov. Holotype, LACM-AHF 1269. San Jaime Bank, Mexico. Height, 20.0, dia- meter, 18.4 mm. X 2 Figure 12: Calliostoma veleroae McLEan, spec. nov. Holotype, LACM-AHF1271. Isla Ladrones, Panama. Height, 15.9, diameter, 17.0 mm. X 2 Figures 13 and 14: Calliostoma keenae McLean, spec. nov. Holo- type, LACM-AHF 1272. Off Laguna Beach, California. Height, 14.9, diameter. 15.5 mm. X 3 Figure 15: Calliostoma keenae. AHF 618-37. San Jaime Bank, Mexico. Height, 8.7, diameter, 8.9 mm. X 3 Figure 16: Calliostoma keenae. AHF 921-39. Clarion Island, Mexi- co. Height, 10.5, diameter, 10.1 mm. X 3 Figure 17: Calliostoma jacquelinae McLean, spec. nov. Holotype, SDNHM 51299. Santa Cruz Island, Galapagos. Height, 11.3, dia- meter, 10.0 mm. XK 3 Figures 18 and 19: Calliostoma santacruzanum McL&an, spec. nov. Holotype, SDNHM 51301. Santa Cruz Island, Galapagos. Height, 7.0, diameter, 6.9 mm. xX 5 Tue VELIcER, Vol. 12, No. 4 [McLean] Plate 62 Figure 6 Mgue Ue Figure 14 Figure 16 Figure 18 i Vol. 12; No. 4 THE VELIGER Page 425 beaded. Base imperforate, basal cords about 12, inter- spaces slightly wider than cords, particularly near the columella where the cords are broader and more widely spaced. Color, yellow brown with slightly darker flam- mules, more pronounced darker and lighter areas at the basal cord, base uniform yellow brown. Type Material: Holotype, LACM-AHF 1272. Type Locality: 58 Fathom Bank. 12 miles off Laguna Beach, Orange County, California, 33°23’47” N, 117° 59’47” W, 58-60 fms., Velero IV station 1680-49, 12 February 1949. Referred Material: Seven lots as follows: AHF 1254-41, 8 miles SW of Cedros Island, Baja California, 65 fms.; AHF 1253-41, 8 miles W of Cedros Island, 65 fms.; AHF 1261-41, 4 miles N of Dewey Channel (Cedros Island), 24 - 25 fms.; AHF 618-37, San Jaime Bank, off Cape San Lucas, Baja California (Plate 62, Figure 15); LACM A375, Clarion Island, Revillagigedo Islands, Mexico, 30 fms.; AHF 918-39, Sulphur Bay, Clarion Island, 45 - 60 fms.; AHF 921-39, N of Clarion Island, 35-56 fms. (Plate 62, Figure 16). Two specimens are in the lot from San Jaime Bank, but the other lots consist of a single speci- men each. The holotype is the largest specimen. Only the holotype and the 2 specimens from San Jaime Bank were live-collected. Calliostoma keenae ranges from Laguna Beach, California (33°12’N) to the Revillagigedo Is- lands, Mexico (18°18’ N). It is chiefly a species of the Californian province since its distribution encompasses the entire outer coast of Baja California. Discussion: Calliostoma keenae differs chiefly from east- ern Pacific Calliostoma species of similar proportion in having strong spiral cords on the early whorls that are nearly devoid of beading. Calliostoma supragranosum CarPENTER, 1864, a shallow water species of the Califor- nia province, differs in having a greater number of ribs that are strongly beaded on the early whorls. Calliostoma leanum (C.B. Apams, 1852) has thicker, more strongly beaded spiral cording. Calliostoma turbinum Datu, 1896, an offshore species of southern California, has fewer spiral cords and has a brassy metallic luster not shown in C. keenae. Calliostoma keenae is dedicated to Dr. Myra Keen of Stanford University, whose warm and friendly manner has been an inspiration to all workers in malacology. Calliostoma jacquelinae McLEan, spec. nov. (Plate 62, Figure 17) Diagnosis: Whorls flat sided, spiral cording consisting of 2 strong peripheral cords, a strong subsutural cord and about 8 intermediate cords of varying strength, base im- perforate, with numerous fine cords, the 4 cords near the columella more prominent. Color light tan, all surfaces highly opalescent with lavender and green. Height, 11.3, diameter, 10.0 mm (holotype). Description of Holotype: Shell relatively small for the genus, thin, whorls flat sided, showing numerous growth scars. Postnuclear whorls 7; periphery defined by 2 strongly projecting, heavily beaded cords with a thin intercalary thread between; immediate subsutural cord stronger than other cords of the body whorl; on the 2"4 and 3 postnuclear whorls there are 3 spiral cords and faint axial sculpture producing a cancellate pattern, the axial cords become obsolete by the 4 whorl and inter- calary cords arise so that there is a total of 7 cords between the subsutural cord and the 1* peripheral cord; these cords are of varying strength and spacing, some are weakly beaded and others are nearly smooth. On the imperforate base there are 4 prominent, slightly beaded cords near the columella and about 15 fine irregular unbeaded cords between these 4 cords and the lower peripheral cord defining the base. Type Material: Holotype, SDNHM 51299, 1 paratype, SDNHM 51300, 1 paratype, LACM 1274, 1 paratype, USNM 679553. Type Locality: South Academy Bay, Santa Cruz Island, Galapagos Islands, Ecuador, 0°45’S, 90°20’ W, 150m [82 fms.], dredged by André and Jacqueline DeRoy, 39 May and 10 June, 1969. Discussion: Calliostoma jacquelinae with its opalescent surface devoid of color pattern and its 2 strong peri- pheral cords is distinct from all other eastern Pacific species. Calliostoma schroedert CLENCH & Acuayo, 1938, in the Caribbean province, resembles this species but lacks sculpture other than the 2 peripheral cords. The species is dedicated to Mrs. Jacqueline DeRoy whose collecting has done much to increase our knowledge of Galapagos Islands mollusks. Page 426 Calliostoma santacruzanum McLEan, spec. nov. (Plate 62, Figures 18, 19) Diagnosis: Whorls flat sided, final whorl! slightly convex, base narrowly umbilicate, spiral cording consisting of 8 beaded intermediate cords, a strong peripheral cord and numerous unbeaded basal cords. Height, 7.0, diameter 6.9 mm (holotype). Description of Holotype: Shell relatively small, post- nuclear whorls 7, base narrowly umbilicate, base defined by a single peripheral cord. On the first 3 postnuclear whorls there are 3 strongly beaded spiral cords. Inter- calary cords arise between these cords resuiting in 8 beaded cords of slightly variable size on the final whorl; the immediate subsutural cord is slightly more prominent. On the base only the cord bordering the umbilicus is beaded, adjacent to it are 3 broad cords, followed by 12 narrow cords, separated by incised grooves. Color light tan with broad brownish maculations, strongly marked along the peripheral cord, green and yellow iridescence showing on the smooth areas between the cords on the early whorls. Whorls flat sided, although a slight concavity is evident at the third whorl and the final whorl shows a slight convexity. Type Material: Holotype, SDNHM 51301. Type Locality: South Academy Bay, Santa Cruz Is- land, Galapagos Islands, Ecuador, 0°45’S, 90°20’ W, 25 fms., dredged by André and Jacqueline DeRoy, 10 June 1968. Efforts to obtain additional material have so far been unsuccessful. Discussion: Although only one specimen is known, which is probably immature, Calliostoma santacruzanum is easily distinguished from other eastern Pacific species. It is the only umbilicate species other than the low-spired, broadly umbilicate C. rema Stronc, Hanna & HERTLEIN, 1933. THE VELIGER Vol. 12; No. 4 LITERATURE CITED Ciencu, WiLuiaM James & RutH Drxon TURNER 1960. The genus Calliostoma in the Western Atlantic. Johnsonia 4 (40) : 1 - 80; plts- 1 - 56 (25 November 1960) Dai, WILLIAM HEALEY 1896. Diagnoses of new species of mollusks from the west coast of America. Proc. U.S. Nat. Mus. 18: 7-20 (April 1896) 1902. _ Illustrations and descriptions of new, unfigured, or im- perfectly known shells, chiefly American, in the U.S. National Museum. Proc. U.S. Nat. Mus. 24: 499 - 566; plts. 27 - 40 (March 1902) 1908. Reports on the dredging operations off the west coast of Central America to the Galapagos, to the west coast of Mexico, and in the Gulf of California. . XIV. The Mollusca and Brachiopoda. Bull. Mus. Comp. Zool., Harvard 43 (6): 205 - 487; 22 plts. (October 1908) 1909. | Report on a collection of shells from Peru, with a sum- mary of the littoral marine Mollusca of the Peruvian zoological province. Proc. U.S. Nat.Mus. 37 (1704): 147 - 294; plts. 20 - 28 (24 November 1909) 1925. Illustrations of unfigured types of shells in the collection of the United States National Museum. Proc. U.S. Nat. Mus. 66 (2554) : 1-41; plts. 1 - 36 (22 September 1925) Keen, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i-xi + 624 pp.; illus. Stanford, Calif. (Stanford Univ. Press) ParKER, Rospert H. 1964. | Zoogeography and ecology of some macro-invertebrates, particularly molluscs, in the Gulf of California and the conti- nental slope off Mexico. Vidensk. Medd. Dansk naturh. Foren. 126: 1 - 178; 15 plts.; 29 text figs.; 7 tables (17 Febr. ’64) Puteri, RupoLF AMANDUS 1860. Reise durch die Wiiste Atacama auf Befehl der chileni- schen Regierung im Sommer 1853-54. Halle, Eduard An- ton; 192+62 pp.; 27 plts. Pitspry, HENRY AuGuUSTUS 1888-1898. Manual of Conchology. Philadelphia, 10 - 17 Vol. 12; No. 4 THE VELIGER Page 427 An Annotated Bibliography of References to Marine Mollusca of the Northern State of Sonora, Mexico ° BY CAROL SKOGLUND Department of Zoology, Arizona State University, Tempe, Arizona 85281 THE FOLLOWING LIST covers references to Mollusca along the coast of the Mexican State of Sonora from Cape Tepoca (Puerto Lobos) to the upper reaches of tidal water in the estuary of the Colorado River. Six separate places have been visited along this coastline since 1869 (see Table 1). Dr. Edward Palmer, a botanist, was the first collector in the area. In 1869 he traveled by boat from Yuma to Guaymas, Mexico, collecting as he went (McVaucu, 1956). The first malacologist was H. N. Lowe (1934, 1935) who collected extensively in the Puerto Penasco area in 1934. Starting in 1948, Dr. S. S. Berry (1953) made several trips to Puerto Penasco and Choya Bay. Both men described new species as a result of their find- ings. Dr. P. Pickens collected opisthobranchs intensively in the same area from 1963 to 1966. His work resulted in descriptions of 19 new taxa by Marcus (1967). The Hancock and Albatross Expeditions were the only ones by sea to reach the eastern shore of the head of the Gulf. Some of the material gathered by dredging was later included in articles by specialists in certain families (Rost, 1955))e Since most references have been to Cholla Bay, this was used. Government maps now show this as Choya Bay, which apparently was the original name. Other names of places have been updated in so far as possible. Where doubt of actual location exists, the original text is given. The references have been grouped as follows: Descriptions of new taxa Range extensions Lists of species Locality descriptions General references Ancillary references Later citations of these same works have been omitted from the list. The author wishes to thank Dr. Dwight W. Taylor, for- merly of the Department of Zoology, Arizona State Uni- versity (and now at the San Diego Natural History Collectors and Expeditions with Areas Visited m Collector ES 1869 Palmer 1889 Albatross 1890 Orcutt 1897! Boundary Comm. 1905 Rhoads 1907 Sykes 1909 Lumholtz 1915 Murphy 1931 Ives 1934 Lowe 1937 Huffman Hancock Exped. 1940 Hancock Exped. 1941 Stanford Exped. 1944 Gifford 1945 Gifford 1947 Baker 1948 Berry 1949 Berry 1950! Bessom 1951 Thurlow 1952 Berry 1954 Mousley Emerson Turver 1955 French Chace 1956 Rogers Wright Berry Moore 1957 Chace DuShane Shasky Colorado river Table 1 XOX ew xX X mouth area El Golfo de Santa Clara Adair Bay x Cholla Bay x X X xX XXX KK XK XK KK XK XK XK XK XK XK XK XK OX OX Puerto Penasco xX XK KK XK XK KK XK XK x (Puerto Lobos) Cape Tepoca x Page 428 Colorado river mouth area El Golfo de Santa Clara Puerto Penasco Cape Tepoca (Puerto Lobos) Adair Bay q Collector P 1958 Chace 1959 Chace 1959: Hall 1963 Pickens 1964 Brown x 1964 Donohue Hanselman Johnson, M. Pickens Paine Rice 1965 Pickens 1966 Pickens Farmer Skoglund x 1967 DuShane x 1968 Johnson, W. S. X X | Cholla Bay x X xX XX XXxXXXXXXXK & x ' publication date Museum, San Diego, California) for many suggestions and for reading the manuscript. DESCRIPTIONS or NEW TAXA Berry, SAMUEL STILLMAN 1945. Two new chitons from the Gulf of California. Amer. Midld. Nat. 34 (2): 491 - 495; 18 figs. (23 August 1945) Chaetopleura (Pallochiton) euryplax, new species, taken under stones at Adair Bay by E. C. Huffman in 1937. A new West Mexican prosobranch mollusk parasitic on Amer. Midld. Nat. 56 (2): 355-357; 2 figs. (October 1956) Turveria encopendema, new genus and species, taken on Encope grandis on outer strand of Cholla Bay by Mr. and Mrs. Harry R. Turver, 1 May 1954, and by S.S. Berry in March 1949 and on May 13, 1952. 1956. echinoids. 1956. Diagnoses of new eastern Pacific chitons. Leafl. in Malacol. 1 (13): 71-74 (19 July 1956) Nuttallina crossota, Lepidozona subtilis, new species, and Stenoplax (Maugerella) conspicua sonorana, new subspecies, taken at Norse Beach near Cholla Bay by S.S. Berry in March 1948 and March 1949. 1957. Notices of new eastern Pacific Mollusca. I. Leafl. in Malacol. 1 (14): 75 - 82 (19 July 1957) Lithophaga (Labis) attenuata rogersi, new subspecies, taken by Mark Rogers and Fred Wright in December 1956 at Cholla Bay, and THE VELIGER Vol. 12; No. 4 Acmaea stanfordiana, new species, taken at nearby Pelican Point by S.S. Berry in March 1948. 1958. Notices of new Eastern Pacific Mollusca. — II. Leaflets in Malacol. 1 (15): 83-90 (28 March 1958) Tiphyocerma preposterum, new genus and species, taken by S.S. Berry at Norse Beach in May 1952, and Olivella fletcherae, new spe- cies, taken in March 1948, 1960. Notices of new eastern Pacific Mollusca — IV. Leafl. in Malacol. 1 (19): 115 - 122 (31 December 1960) Acmaea acutapex, new species, taken at “Punta Cholla, W. of Puerto Pefiasco ...” by S.S. Berry in March 1948; Neosimnia vid- leri tyrianthina, new subspecies, Berry and Moore, Cholla Bay, 1956; Mitra (Tiara) lindsayi, new species, off Puerto Pefasco, 10 fms., H. N. Lowe, February 1934. 1964. Notices of new eastern Pacific Mollusca. — VI. Leafi. Malacol. 1 (24): 147 - 154 (29 July 1964) Melampus mousleyi, new species, found in the upper estero of Cholla Bay by S.S. Berry in March 1948. CamMPBELL, G. Bruce 1964. New terebrid species from the eastern Pacific (Mollusca: Gastropoda). The Veliger 6 (3): 132 - 138; plt. 17 (1 January 1964) Terebra (Strioterebrum) adairensis, new species, found at Adair Bay by Dorothy Brown. Dati, WituiamM HEaLey 1891. Scientific results of explorations by the U.S. Fish Com- mission steamer Albatross. XX. -— On some new or interesting West American shells obtained from the dredgings of the U. S. Fish Commission steamer Albatross in 1888 and from other sources. Proc. U.S. Nat. Mus. 14 (849): 173-191; plts. 5-7 (24 July 1891) Eupleura var. limata, described from the head of the Gulf of Cali- fornia near the estuary of the Colorado River. 1894. On some species of Mulinia from the Pacific Coast. The Nautilus 8 (1): 5-6; plt. 1 (2 May 1894) Mulinia coloradoensis, new species, head of the Gulf of California in the estuary of the Colorado River, found by Dr. E. Palmer. 1910. New shells from the Gulf of California. The Nauti- lus 24 (3): 32 - 34 (2 August 1910) Cymatium adairense, new species, found off Adair Bay. 1913. Proc. U.S. Nat. Mus. 45 (2002) : 587 - 597 Amphissa (Cosmioconcha) palmeri and Erycina colpoica, new spe- cies, from the head of the Gulf of California, found by Dr. E. Palmer. Diagnoses of new shells from the Pacific Ocean. (11 June 1913) Notes on the Semelidae of the West Coast of America, including some new species. Proc. Acad. Nat. Sci. Phila- delphia 67; 25 - 28 (2 March 1915) Abra tepocana, new species, taken “off Cape Tepoca, Lower Cali- fornia.” 1915. Vol. 12; No. 4 THE VELIGER Page 429 DuSuaneg, HELEN & James Hamitton McLEAN 1968. Three new epitoniid gastropods from the Panamic prov- ince. Los Angeles County Mus. Contr. Sci. 145: 6 pp.; 6 figs. (14 June 1968) Epitonium (Asperiscala) huffmani, new species, found at Cholla Bay by Al Huffman in April 1937. Lowe, HERBERT NELSON 1935. | New marine Mollusca from West Mexico, together with a list of shells collected at Punta Penasco, Sonora, Mexico. Trans. San Diego Soc. Nat. Hist. 8 (6): 15 - 34; plts. 1-4 (21 March 1935) A list of 299 species, including 3 new species: Leda (Adrana) penas- coensis, Turbonilla (Ptycheulimella) penascoensis, and Clathrodrillia pilsbryi, which were dredged at 10 fms. by Lowe in 1934. Marcus, EvELINE DU Bors-REYMOND & ErRNsT Marcus 1967. American opisthobranch mollusks. Studies in tropical oceanography (Univ. Miami Inst. Marine Sci., Miami, Flori- da), no. 6, 256 pp. An excellent account of material collected by Peter Pickens and his associates from November 1963 to April 1966. This work includes descriptions of 2 new genera and species, 14 new species, and 3 new subspecies. Thirty-nine species are reported from Puerto Pefiasco, 5 from Cholla Bay, and 9 from Puerto Lobos. Pitspry, Henry AuGcusTus 1910. A new species of Marinula from the head of the Gulf of California. Proc. Acad. Nat. Sci. Philadelphia 62: 148 - 149; 1 fig. (23 May 1910) Marinula rhoadsi, new species, from “Hardie River, Lower Califor- nia,” found by S. N. Rhodes in February 1905. Pitspry, Henry Aucustus « AxEL ADoLF OLssoNn 1945. _ Vitrinellidae and similar gastropods of the Panamic prov- ince. Part I. Proc. Acad. Nat. Sci. Philadelphia 97: 249 to 277; pits. 22 - 30 (27 December 1945) Teinostoma politum ultimum, new subspecies, from ‘Rocky Bluff, Bahia de Adair, Sonora ...,” collected by Earl C. Huffman. SHasky, Donatp R. 1961. | New deep water mollusks from the Gulf of California. The Veliger 4 (1): 18-21; plt. 4, figs. 1-10 (1 July 1961) Trigonostoma campbelli, new species, from off Puerto Penasco in 10 fms., collected by H.N. Lowe in February 1934. STEARNS, ROBERT EDWARDS CARTER 1893. Description of a new species of Nassa from the Gulf of California. The Nautilus 7 (1): 10-11 (7 June 1893) Nassa brunneostoma, new species, from the Gulf of California near the mouth of the Colorado River, collected by Dr. E. Palmer. RANGE EXTENSIONS Cate, Crawrorp NEILL 1969. A revision of the eastern Pacific Ovulidae. ger 12 (1): 95-102; plts. 7- 10; 3 maps The Veli- (1 July 1969) The type locality for Jenneria pustulata (Licutroot, 1786) is designated as Cholla Bay, Punta Pefiasco, Sonora, Mexico. Florence Thurlow found the species at Cholla Bay in sand in April 1951 (personal communication). Simnia rufa (Sowersy, 1832) and S. aequalis aequalis (SowERBY, 1832) are reported from Adair Bay. Neosimnia quaylei Lowe, 1935 and N. vidleri tyrianthina Berry, 1960, become synonyms of S. a. aequalis. 1969. The eastern Pacific cowries. The Veliger 12 (1): 103 - 119; plts. 11-15; 3 maps (1 July 1969) Erosaria albuginosa (Gray, 1825) is reported from Puerto Pefiasco. Dai, WiLutiAM HEaLey 1897. | Report on the mollusks collected by the international boundary commission of the United States and Mexico, 1892- 1894. Proc. U.S. Nat. Mus. 19 (1111): 333-379; plts. 31 - 33 (27 January 1897) Tivela crassatelloides found near the mouth of the Colorado River at the mouth of Rio Hardy. DALL, WILLIAM HEALEY, & PAUL BARTSCH 1909. A monograph of the West American pyramidellid mol- lusks. U.S. Nat. Mus. Bull. 68: 1 - 258; 30 plts. (13 December 1909) Pyramidella mazatlanica dredged off Cape Tepoca at the U.S. Bureau of Fisheries station 3019 in March 1889 by the Albatross (Townsend, 1901). DonoHUuE, JERRY 1966. The range of Trivia myrae CAMPBELL. The Veliger 9 (1): 35-36; 1 map (1 July 1966) Found at Puerto Pefiasco by Nora Donohue in April 1964. FarMER, WESLEY MERRILL 1967. Notes on the Opisthobranchia of Baja California, Mexi- co, with range extensions - II. The Veliger 9 (3) : 340 - 342; 1 text fig. (1 January 1967) Chromodoris banksi and Dirona picta were found one mile south of Puerto Pefiasco in February 1966. Husss, Cary Leavitt « RoBERT RusH MILLER 1948. The Great Basin with emphasis on glacial and _post- glacial times. IT. The zoological evidence. Bull. Univ. Utah 38 (20) : 17 - 166; 1 map (30 June 1948) Cerithidea albonodosa found above the present tide level near the lower Rio Hardy (p. 111). McLean, James HamMILTON 1967. | West American species of Lucapinella. The Veliger 9 (3): 349-352; plt. 49; 3 text figs. (1 January 1967) Lucapinella milleri reported from Puerto Penasco. A. Huffman. Murpny, Ropert CUSHMAN 1917. Natural history observations from the Mexican portion of the Colorado Desert. Proc. Linn. Soc. New York (28-29): 43 - 114 (11 December 1917) Cerithidea sacrata Goutp found in the area of Laguna Salada, Baja California in March 1915 by Murphy. Page 430 Suasky, Donatp R. 1959. Range extensions for gastropods of tropical West Amer- ica. Minutes Conch. Club South. Calif. (186): 15-18 Mitrella millepunctata range extension to Cholla Bay. 1961. Notes on rare and little known Panamic mollusks. The Veliger 4 (1): 22-24; plt. 4, figs. 11-16 (1 July 1961) Tenaturris nereis taken at Puerto Penasco by Shasky. STEARNS, Ropert Epwarps CarTER 1894. The shells of the Tres Marias and other localities along the shores of Lower California and the Gulf of California. Proc. U.S. Nat. Mus. 17 (996): 139 - 204. Cardium elatum found at Pinacate Bay [Adair Bay?] by Dr. E. Palmer (p. 151). Stronc, ArcuipaLp McCuiure « Hersert NeEtson Lowe 1936. | West American species of the genus Phos. Trans. San Diego Soc. Nat. Hist. 8 (22): 305 - 320; plt. 22 Phos gaudens taken by H.N. Lowe in 10 fms. off Puerto Penasco. LISTS or SPECIES BErry, SAMUEL STILLMAN 1956. See locality descriptions Burcu, Beatrice LaRue 1967. | Murex shells. Cholla Chatter (Cholla Bay Sports- men’s Club, Phoenix, Arizona) 10 (5): 8-10 (May 1967) A list of Muricidae to be found in the Cholla Bay area with infor- mation on life cycles of some species. Burcu, JoHN Quincy 1967. The olive shells of Cholla Bay. Cholla Chatter (Cholla Bay Sportsmen’s Club, Phoenix, Arizona) 11 (10): 8-9; 1 plt. (November 1967) A review of the seven members of the Olividae found at Cholla Bay. DuSuHane, HELEN « ELLEN BRENNAN 1969. _A preliminary survey of mollusks for Consag Rock and adjacent areas, Gulf of California, Mexico. The Veliger 11 (4): 351 - 363; 1 map (1 April 1969) Seven species collected by DuShane at El Golfo de Santa Clara in November 1967 are listed. Girrorp, Epwarp WINsSLow 1945. Archaeology in the Punta Pefiasco region, Sonora. Amer. Antiq. 11: 215-221; fig. 29 (May 1945) A list of shells found at old camp sites and on nearby dunes. HErTLEIN, LEo Georce & WILLIAM KerirH EMERSON 1956. Marine Pleistocene invertebrates from near Puerto Pen- asco, Sonora, Mexico. Trans. San Diego Soc. Nat. Hist. 12 (8): 154-176; plt. 12; 2 maps (7 June 1956) A list of fossil shells taken at Puerto Penasco and Pelican Point (Cholla Bay) with comparisons to present day fauna. THE VELIGER Vol. 12; No. 4 Hornapay, WILLIAM T. 1909. Camp-fires on desert and lava. Sons, New York, 366 pp. Five species found on the shores of Adair Bay by Godfrey Sykes in 1907 (p. 240). Charles Scribner’s Jounson, MyrtLe EvANGELINE 1968. The cone shells of Cholla Bay. Cholla Chatter (Cholla Bay Sportsmen’s Club, Phoenix, Arizona) 11 (12): 4-7; figs. 1-4 (December 1968) Lists cones found in the Penasco-Cholla Bay area. Keen, A. Myra 1947. Species of mollusks collected by the Stanford Expedition, 1941, to be added to the list published by H.N. Lowe, 1935 (Trans. San Diego Soc. Nat. Hist., vol. 8, no. 6, pp. 27 - 34). Min. Conch. Club South. Calif. (75): 3-4 (Decemb. 1947) [published anonymously but actually by A. Myra Keen as per personal communication April 20, 1969.] Sixty-one species to be added to the Puerto Pefiasco area list. Lowe, H.N. 1934. See locality descriptions. Marcus, E. « E. Marcus 1967. See descriptions of new taxa. Rice, THomas C. 1964. Mexican shelling. Pacif. Northwest Shell News 4 (3, 4): 29-34 (Fall 1964) A trip to Puerto Penasco and Cholla Bay in February 1964 with George and Virginia Hanselman results in a preliminary list of 67 species. 1966. H & R expedition species check list. Pacif. North- west Shell News 6 (1): 4, 13 - 22 (January 1966) Lists 84 species from Puerto Penasco and 52 species from the Cholla Bay area taken by Tom Rice in February 1964. Suasky, Donatp R. 1958. See locality descriptions. LOCALITY DESCRIPTIONS Berry, SAMUEL STILLMAN 1956. _A tidal flat on the Vermilion Sea. Journ. Conchol. 24 (3): 81 - 84 (February 1956) An excellent description of Cholla Bay; it includes the major species to be found in each habitat from the back estuary to the low tide line. DuSHANE, HELEN 1957. Marine treasures from the beach at Punta Penasco. Desert 20 (10): 17-20; 2 figs.; 2 maps (October 1957) Collecting in Cholla Bay, with a photograph of 28 species found by the DuShanes in April 1957 (personal communication) . Vol. 12; No. 4 THE VELIGER Page 431 Lowe, HERBERT NELSON 1934. On the Sonoran side of the Gulf. The Nautilus 48 (1): 1-4 (10 July 1934) ; 48 (2): 43-48 (15 Oct. 1934) General account of a trip to Puerto Penasco in February 1934 with information on habitats of mollusks seen. Suasxy, DonaLp R. 1958. Collecting stations — Puerto Penasco, Son., Mexico. Min. Conch. Club South. Calif. (176): 6 - 8; 1 fig. (April 1958) Information on types of habitats and species to be found, from a trip in March 1957. GENERAL REFERENCES FaRMER, WESLEY MERRILL 1968. _Tidepool animals from the Gulf of California. Wes- word Co., San Diego, Calif.; 69 pp.; 170 figs.; 23 plts. Drawings of many common mollusks of both El Golfo de Santa Clara and Puerto Penasco. Keen, A. Myra 1958. Sea shells of tropical West America; marine mollusks from Lower California to Colombia. i- xi + 624 pp.; illus. Stanford Univ. Press, Stanford, Calif. (5 December 1958) A comprehensive work with references to ranges of many species to the head of the Gulf of California and to Puerto Penasco. ANCILLARY REFERENCES Baker, Epwarp P 1947. The Bakers take a trip to Mexico. Min. Conch. Club South. Calif. 72: 14-19 (August 1947) An account of a shell collecting trip to Puerto Penasco and Cholla Bay in January 1947 Berry, SAMUEL STILLMAN 1953. Molluscan notes from the Puerto Pefiasco region, Sonora (abstract). Min. Conch. Club South. Calif. 131: 3 (Sept.) Trips to the area by S.S. Berry in 1948, 1949, and 1952 resulted in 704 species being taken, many of which were undescribed. 1963. Diagnoses of new eastern Pacific chitons. II. Leafl. in Malacol. 1 (22): 135-138 (29 March 1963) Lepidozona pella, new species, from San Felipe, Baja California, is compared with L. subtilis Berry, 1956 from Puerto Penasco. Burcu, JoHN Quincy (ed.) 1949. _ Extracts from the Minutes of Conch. Club South. Calif. 92: 7 H. Turver spoke of collecting 300 species at Cholla Bay. The short account mentions some of the species, and states that sizes are larger than in the Guaymas area. 1950. Extracts from the Minutes of Conch. Club South. Calif. 104: 4 (September 1950) L. Bessom gave an account of a trip to Puerto Pefiasco and Cholla Bay. 1953. Extracts from the Minutes of Conch. Club South. Calif. 125: 6 (January/February 1953) S. S. Berry spoke on “Molluscan notes from Puerto Penasco region.” He stated that he has material from the region from Lowe, Keen, Turver, Mousley, and the Fletchers. 1954. Extracts from the Minutes of Conch. Club South. Calif. 138: 40 (May 1954) Louis B. Mousley found a large group of Cancellaria acuminata live in Adair Bay in January 1954. 1954. Extracts from the Minutes Conch. Club South. Calif. 139: 60 (June 1954) The Harry Turvers report good collecting at Puerto Pefiasco. 1955. Extracts from the Minutes of Conch. Club South. Calif. 152: 12 (November 1955) Mr. and Mrs. Mead French gave a report on a recent trip to Cholla Bay. 1959. Extracts from the Minutes Conch. Club South. Calif. 190: 14 (July/August 1959) S. Ralph Hall found 2 dead Spondylus shells at Cholla Bay. Burcu, THomas Apams (ed.) 1969. Cone shells of Cholla Bay. Cholla Chatter (Cholla Bay Sportsmen’s Club, Phoenix, Arizona) 12 (1) :9; 1 fig. Conus regularis found by Carol Skoglund at Cholla Bay boat landing in August 1966. 1969. | Wormfish search. Cholla Chatter (Cholla Bay Sportsmen’s Club, Phoenix, Arizona) 12 (6): 24-25 (June) Cyclinella sp. found in the Cholla Bay estuary in May 1969. Cuace, EMERY Perkins & Erste Marcaret Herpst CHACE 1967. | Conchological reminiscences. Recollections of Emery P. Chace and Elsie M. Chace with the help of our notebooks. San Diego Soc. Nat. Hist. 38 pp. Collecting trips to Cholla Bay were made by the Chaces in 1955, 1957, 1958, and 1959. GaRDNER, ERLE STANLEY 1969. Clamming at El Gulfo. Desert 32 (7): 12-15, 33 (July 1969) Clam digging for food; no species names given. Ives, RonaLp LorENz 1951. High sea levels of the Sonoran shore. Amer. Journ. Sci. 249: 215 - 223; plts. 1-2; 2 figs. (March 1951) Deposits of Chione cancellata and Turritella above present shoreline used as indicators of past changes. 1959. = Shell dunes of the Sonoran shore. Amer. Journ. Sci. 257: 449-457; plts. 1-2; 3 figs. (June 1959) Chione cancellata a component of the shell dunes. 1963. The problem of the Sonoran littoral cultures. Kiva 28: 28 - 32; 1 fig. Page 432 THE VELIGER Vol. 12; No. 4 Turritella leucostoma and Chione cancellata used to identify old shorelines. Jounson, MyrtLe EvANGELINE 1964. | My hobby — shell collecting. Cholla Chatter (Cholla Bay Sportsmen’s Club, Phoenix, Arizona) 8(3): 14 to 15 (March 1964) Collecting at Cholla Bay. JoHNson, WILLIAM Scott 1968. Ecology and seasonal fluctuations of an intertidal Sar- gassum-Hyale-Barleeia association at Punto Penasco, Mexico (abstract) . Southwest. and Rocky Mt. Div., Amer. Assoc. Adv. Sci. 44t* ann. meet. 28 April - 1 May 1968 LuMHOLTz Cari 1912. New trails jn Mexico. York Dosinia ponderosa seen at la Salada, near the mouth of the Colo- rado in 1909 by Lumholtz (p. 256). Charles Scribner’s Sons, New Rost, HELEN MacGrniTiz, GeorcE Esper & Nettie MacGIniTIEz 1949. Natural history of marine animals. McGraw-Hill, New York. 473 pp.; illus. Lamellaria orbiculata seen on white encrusting sponge at Puerto Penasco (p. 372). Orcutt, CHARLES RUSSELL 1891. A visit to Lake Maquata. West. Amer. Scient. 7 (59) : 158 - 164 (April 1891) Cerithidea and clams of the genus Venus were found to the west- ward of Lake Maquata. PaInE, Rosert T. 1966. Function of labial spines, composition of diet, and size of certain marine gastropods. The Veliger 9(1): 17-24; 2 text figs. (1 July 1966) Observations on Acanthina angelica made at Puerto Penasco in March 1964. 1955. A report on the family Arcidae (Pelecypods) . Allan Hancock Pacif. Exped. 20 (2) : 17 text figs. 177 - 249; plts. 11 - 16; (10 November 1955) Offshore work in 1937 and 1940 at Puerto Penasco and at Cape Tepoca. Anadara multicostata and A. alternata reported from Penasco, and A. alternata from Tepoca. LITERATURE CITED McVaucu, RocEers 1956. | Edward Palmer, plant explorer of the American West. Univ. Oklahoma Press, Norman, Okla. 430 pp. TowNnsEND, C. H. (compiler) 1901. Dredging and other records by the U.S. Fish Commis- sion steamer Albatross with the bibliography relative to the work of the vessel. Extr. U.S. Fish. Commiss. Rep. of 1900; Washington, D.C., pp. 387 - 562; plts. 1-7 Vol. 12; No. 4 THE VELIGER Page 433 The Systematics and Some Aspects of the Ecology of the Genus Dendronotus (Gastropoda : Nudibranchia ) BY GORDON A. ROBILLIARD Department of Zoology and Friday Harbor Laboratories, University of Washington, Seattle, Washington 98105 \ (Plates 63 and 64; 28 Text figures) INTRODUCTION Tue cGENuS Dendronotus has had a long and chaotic literary history, beginning in 1774 when Ascanius de- scribed the type species under the name of Amphitrite frondosa. MULLER (1776) incorporated this species into his rather all-inclusive genus Doris as Doris arborescens. Cuvier (1797) established the genus Tritonia and he included A. frondosa as Tritonia arborescens in 1817. AL- DER & Hancock (1845), on morphological bases, estab- lished the genus Dendronotus as separate from Tritonia with Doris arborescens Murr, 1776 as the type species. Subsequently, the genus has been referred to as Dendro- notus with the name of the type species D. frondosus (Ascanius, 1774) being used for the first time in the 1904 edition of the Plymouth Marine Invertebrate Fauna (Eutot, 1910). During the late 18", 19 and early 20" centuries, the species of Dendronotus, especially D. frondosus, were, with only a few exceptions (ALDER & Hancock, 1845; VeErR- RILL, 1870; MAcFarLanp, 1966), based on sketchy, in- adequate descriptions and diagrams of one or a few animals. Consequently, there are no reports on the range of intraspecific variation of the various taxonomically important characters, the radula excluded, for any species. OpHNER (1934), in an effort to point out some of the pitfalls facing opisthobranch taxonomists and what they might do to avoid the same, states: “... I think it is necessary to give good figures of the whole animal, and not of details only ... as external shape and features provide not only an immediate means of recognition, but often also important systematic characteristics .... The literature on nudibranchs is full of detailed descriptions but too little of comparisons, which, however, are specially desirable in this group, because of the difficulty of finding representative characters in these soft-bodied animals ...” During a comparative study of the nudibranch genus Dendronotus from the San Juan-Puget Sound area, Wash- ington, I found that there were apparently 3 more species than were presently accepted names. In this paper I have redescribed the 6 known and accepted species {D. fron- dosus (AscaAntus, 1774), D. iris Cooper, 1863, D. robus- tus VERRILL, 1870, D. gracilis Bapa, 1949, D. albus Mac- FaRLAND, 1966, and D. subramosus MacFaranp, 1966}. I have reinstated as well as redescribed two species, D. dali Bercy, 1879 and D. rufus O’DonocHuE, 1921, synonymized with D. frondosus by OpHNER (1936). I consider D. venustus MacFarLanD, 1966 a synonym of D. frondosus. Finally, I have described a new species of Dendronotus. For the sake of completeness, a diagnosis of the order, family, and genus, drawn from the literature, is included. I have included a definition or a figure or both of each taxonomically significant character referred to in this paper. Brief mention is made of a number of aspects of the nudibranchs’ ecology and life history. MATERIALS anp METHODS Because of the distinct ecological differences of the local species of Dendronotus, the animals were collected from a number of different areas from August 1966 to June 1967 (see Appendix I for longitude and latitude of the collection sites). Dendronotus frondosus was collected from the moorage floats in Friday Harbor and Mitchell Bay during August, September, and early October of 1966 and again in April and May of 1967. During late October and throughout November, 1966, they were often found in the seawater tables at the Friday Harbor Laboratories. They have been Page 434 collected in February, 1967 and 1968, at Cantilever Pier in 35 m of water. From June, 1965 to May, 1967, Dendronotus iris was collected incidentally while the research vessel, M. V. “Hydah,” was otter trawling for flat fish in East Sound and Bellingham Bay. Occasionally, it was dredged in West Sound and Harney Channel. During June, 1967, I collected 15 animals while SCUBA diving at Departure Bay and Clarke Rock, Nanaimo, B. C. Dendronotus subramosus was collected at Peavine Pass, Edwards Reef, Lonesome Cove, and Low Island during late August through to December, 1966 and in July, 1967. Dendronotus rufus was obtained from the outlet of the storm and sewer drain at Alki Point, Seattle during November through February of 1966 to 1967 and 1967 to 1968, respectively. Dendronotus dalli was collected on August 20, 1966; from October, 1966 to January, 1967, and from January 1 to 4, 1968, on the Victoria Break- water, Victoria. Dendonotus albus was collected at Lone- some Cove, Brown Island, Collins Cove, and Edwards Reef from September to December, 1966. The new species of Dendronotus was obtained from Lonesome Cove, Brown Island, the Cantilever Pier, and the Victoria Breakwater from July, 1966 to January, 1967, although seldom in abundance. All of the species were collected less commonly in places other than those mentioned above. The last 5 species I collected while SCUBA diving because survival is about 5 per cent when dredged and about 95% when collected while diving. Each animal plus its substratum, usually a hydroid, was placed in a plastic bag which could be tied shut and put in a canvas collecting bag. Ecological data, such as location, depths, currents, substratum, bottom type, possible food items, and reproductive activity were recorded on a sheet of 1.5 mm white matte plastic with a soft lead pencil. Each nudibranch was kept in an individual container on the seawater table for about 2 days during which time the fecal pellets were examined to determine what the animal was eating prior to collection. A detailed descrip- tion of each individual was then recorded on a prepared worksheet, special attention being paid to body propor- tions and dimensions, cerata, rhinophores, lip and veil papillae, color, and the ecological data mentioned above. A total of 15 Dendronotus rufus, 23 D. subramosus, 81 D. albus, 26 Dendronotus spec. nov., 28 D. iris, 32 D. frondosus, and 53 D. dalh were thus described. Many more specimens of each species were collected from May to September, 1967 and from January to March, 1968. They were checked to see if the above-mentioned charac- ters fell within the range of variation described for the species. THE VELIGER Vol. 12; No. 4 To study the reproductive system, jaws and radula, each animal was relaxed with succinylcholine (BEEMAN, 1968), killed with 5% seawater formalin, and stored in 5% seawater formalin with 0.25% Ionol C. P-40 (Rosi- LIARD, 1969). The ducts of the isolated genital system were separated to facilitate study of the relative position and size of component parts. The “female gland mass,” consisting of the fertilization chamber, “albumin” gland, membrane gland, and mucous gland (GuisE.in, 1965) was not drawn because the component parts are very fragile and cannot be easily separated. Furthermore, the size and shape of this organ depend very much on the reproductive activity of the genital system and are of minor taxonomic signifi- cance. The excised buccal mass, placed in a petri dish, was left until all the tissue had decomposed. The radula was easily extracted from jaws, cleaned, and mounted in a non- resinous mounting medium (Turtox CMC-10). The jaws were washed and preserved in 5% seawater formalin. Both the radulae and the jaws were drawn using a camera lucida and the drawings were supplemented by reconstructions based on photographs. Specimens of all the species studied have been depos- ited in the California Academy of Sciences, the Smith- sonian Institution, and the Canadian National Museum. SPECIES Introduction to Species Descriptions I have tried to use large samples of each species, consisting of animals from different localities, in order to account for the considerable intraspecific variation that occurs in the nudibranchs. Only living or well-relaxed, freshly pre- served adult (or near-adult) animals have been described because of the paucity of very young specimens. The described animals are from a relatively limited area and there may be even more variation throughout their whole geographical range. ’ I have tried to compare and contrast each species with the other species by describing quantitatively (or quali- tatively, if more appropriate) the same structure in each species. Where the description is quantitative, the first number(s) represents the mode of the measurements or counts, determined from all the animals used, followed by the range of variation enclosed in parentheses (2 g., body length, 5.0-6.0 (3.0-9.0) cm-L). Within the description of each species, I have tried to include the useful and accurate portions of earlier ac- counts. Because earlier authors generally have not em- Vol. 12; No. 4 THE VELIGER Page 435 \ ployed a consistent nomenclature when referring to the anatomy and morphology of Dendronotus, I have applied distinct terms to each taxonomically significant structure and have defined and figured them. Although a few of the terms are original, most have been used before; syno- nyms and their references are included in Appendix II. Except for the jaws, radula, and genital organs, the internal organs are not described as they appear to be very similar in all the species examined. For relatively complete descriptions and accurate diagrams of the inter- nal organs, the reader is referred to ALDER & HANCocK (1845), Bercu (1894), OpHNnER (1936), and MacFar- LAND (1966). The ganglia and nerves of the central ner- vous system, although slightly different in each species, are not described because they are difficult to isolate and the differences do not appear to be significant on the species level. BERcH (1879, 1894) and MacFarianp (op. cit.) gave good descriptions and figures of the central nervous system. The choice of important taxonomic characters is neces- sarily arbitrary (Mayr, 1965) but familiarity with a taxon prepares one, potentially at least, to choose those charac- teristics which will be most enlightening. After examining 7 species of Dendronotus, I have chosen several external and internal characters, listed below, on which I have based the species descriptions. These characters show the greatest intraspecific consistency while being demonstrably different interspecifically. Six of the 9 named species of Dendronotus plus a new species were found in the study area. The other species, D. robustus and D. gracilis, are included for completeness, the description being based on a compilation of the avail- able literature. This latter type of description is relatively unsatisfactory and should be used with some caution because of differences of opinion between biologists con- cerning the taxonomic significance of particular characters. Synonymy and Taxonomic Remarks Each synonymy cites only the first reference to a name or new combination of names that were already in use. To insure accuracy in the fairly exhaustive search for all the names used for a species of Dendronotus, I have tried to examine the original descriptions. When this has not been feasible, all other references concerning the elusive de- scription were utilized. Where it is appropriate, I have made some remarks concerning the literary history of the species in an effort to indicate why certain authors felt new species should be established while others felt that lumping of certain species would be more realistic. Body Form, Dimensions, and Texture The body of Dendronotus is limaciform or “sluglike,” but differences in body proportions determine whether or not the species is “delicate” or “heavy.” The length (L) of the nudibranch is measured from the tip of the tail to the anterior edge of the veil between the two medial veil papillae when the animal is actively crawling (Figure 1). CL 1.0cm Figure 1 Ventral view of Dendronotus dalli, showing lip and veil papillae, position of the mouth, and the foot CE = cerata CL = clavus CP = crown papillae = foot LI = lip papillae LP = lateral papilla MGA = male genital aperture RST = rhinophore stalk VP = veil papillae The width (W) and height (H) are measured halfway between the first and second pair of cerata over the cardiac prominence, again when the animal is actively crawling (Figures 2, 3). The height is the distance from the sub- stratum to the top of the cardiac prominence. The width is taken at the widest part of the body, exclusive of the edge of the foot, at the same point. These dimensions may vary more than 10% in a single animal because of its plasticity. Texture refers to the surface of the epidermis. In most species, the epidermis is quite smooth, but in Dendronotus frondosus, D. subramosus, and a few D. albus, there are few to many conical (or subconical) papillae of various sizes scattered over the dorsum, particularly the cardiac prominence (Figure 3). They are usually capped with a yellow to cream colored pigment. In all the specimens examined, the anus and genital orifice opened at approximately the same place. The anus, often on a raised papilla, is located about halfway along an imaginary line joining the bases of the 1* and Page 436 \t g AP CE Ay Z VP SS yRst \ \ fe Ze Fe WibxS 2g : é. S aL ES (Fav Le Wsy NARS —% Y V ile a ANS CP 1.0cm Figure 2 Dorsal view of Dendronotus albus, showing the external features of the body and appendages AP = anal papilla CE = cerata CP = crown papillae IL]? = RSH = rhinophore sheath VL = veil CL = clavus lateral papilla RST = rhinophore stalk VP = veil papillae 2-4 cerata on the right side. The genital openings are located just anterior to the base of the 1* ceras on the right side, usually from 4 to ? of the way up the side (Figure 3). 3 ‘\ i ee Wee Gf RW RST RSH FGA = MGA Z SS s a CL Zi aa CP 1.0cm VP VL Figure 3 Lateral view of Dendronotus subramosus, showing the genital apertures and the cardiac prominence and papillae AP = anal papilla BP = body papillae CE = cerata CL = clavus CP = crown papillae CPR = cardiac prominence - FGA = female genital aperture MGA = male genital aperture RSH = rhinophore sheath RST = rhinophore stalk VL = veil VP = veil papillae THE VELIGER Vol. 12; No. 4 Foot The foot (Figure 1) is briefly described, emphasis being placed on the length, width, shape, and functional aspects. The length (L) is the distance from the tip of the tail to the most anterior edge of the foot, while the width (W) is measured as the widest part of the foot. Both measure- ments are taken while the animal is crawling. The discus- sion of the functional aspects of the foot, particularly in relation to the animal’s feeding habits, is based partly on field and laboratory observations and partly on specu- lation. Further studies are being made to determine the relationship between the morphology of the foot and the animal’s feeding habits. Color Color is one of the most variable characters in Dendro- notus. However, if the variations are recognized and some caution is exercised, color can be used as a guide in identi- fying the species. In many cases, there are distinct patterns (cf. D. subramosus) that occur consistently and allow one to identify the animal even though the ground color is different. As a final guide, color plates are presented (Plates 63 and 64). Cerata The term cerata (Figures 2,3) should probably be reserved for the dorsal appendages of the Aeolidiacea (Morton, 1958), but, because the term has been more or less ac- cepted, and because it distinguishes between dorsal pro- cesses (rhinophores and “cerata’”’), I have used it in this paper. The possible function of the cerata as respiratory organs is evident from the nomenclature that has been applied by previous authors (see Appendix II) although there has been no experimental work done to prove this. Some aeolids have cerata with cnidosacs which presum- ably are for protection (EpMuNps, 1966), but there appear to be no cnidosacs in Dendronotus (PRuvot-Fot, 1954; THompson, 1960a). Other aeolids are able to autotomize the cerata as a possible protective mechanism (Epmunps, op. cit.; Garstanc, 1889; Stasek, 1967; Tuompson, 1964), but the dendronotids appear unable to accomplish this feat (unpublished observations). I have, however, examined a number of specimens which have lost parts of or whole cerata, rhinophores, or veil papillae, probably from attacks by predators such as fish. The branching patterns (Figure 4) and the size of the cerata are relatively distinct and consistent within a spe- cies. Each ceras has 1 - 5 main branches, defined as those large branches arising directly from the body or from very Vol. 12; No. 4 THE VELIGER Page 437 Figure 4 Branching patterns of cerata A. “Fan-shaped” pattern with the left ceras showing all 3 branches arising from a single stalk while the right ceras shows the lateral branch arising first and the medial 2 arising above this. B. “Rosette” pattern. C. Primary (1°), secondary (2°), and tertiary (3°) branching of a single ceras. near the base of the ceras. From these main branches arise a few to many secondary and tertiary branches (Figure 4c). Normally the medial main branch is the longest, the others becoming progressively shorter with the lateral branch being the shortest. In some species, e. g., Dendronotus iris, it is difficult to distinguish the main branches from large secondary branches and the choice becomes arbitrary. There are two basic patterns which I have called the “fan-shaped” pattern (Figure 4a) and the “rosette” pattern (Figure 4b). The “fan-shaped” ceras is oriented with the “fan” at right angles to the long axis of the body. The “rosette” pattern consists of the branches radiating from the top of a stout stalk. In a few specimens, particularly of D. rufus, there are small tufts called “accessory” cerata appearing in irregular groups between the main cerata, especially over the cardiac prominence. The first pair of cerata usually is the largest with suc- cessive posterior pairs becoming smaller and less branched. The distance between successive pairs usually decreases posteriorly. The reduction in the number of main branches appears to be due to the loss of the lateral branches. Rhinophore and Clavus It has been generally thought that the rhinophores, par- ticularly the clavus, “‘on the basis of their position, struc- ture and innervation” (Koun, 1961, p. 300) are used as chemoreceptors, especially for the detection of food. Most of the experimental work with food extracts has failed to show conclusively that the rhinophore is any more sensi- tive to chemosensory stimulation than any other part of the cephalic region (KoHn, 1961). However, WoLTER (1967) has shown that the rhinophore is a chemosensory structure, stimulated by food, in Archidoris tuberculata, Polycera quadrilineata, Aeolidia papillosa, and Facelina drummondt. The 3 important components of the rhinophore are the lateral papilla, the crown papillae, and the clavus (Fig- ures 2, 3) (see Appendix II for synonyms). The presence or absence, size, pattern of branching, and point of origin on the rhinophore stalk are important in describing the lateral papilla, the function of which is unknown. The crown papillae, vertical prolongations of the rhinophore sheath, vary in length, number, degree of branching and arrangement on the sheath. The leaves of the clavus vary in size, shape, number, and color. The overall shape of the clavus is also important. In some cases, the position at which the rhinophores are held while the animal is crawling is distinctive. Head, Lips, and Veil The cephalic region of Dendronotus is very sensitive and there is a strong indication that the veil papillae, and possibly the lip papillae, serve as contact chemoreceptors (unpublished observation) as do the oral tentacles of some aeolids (Kon, 1961). As well as indicating the existence of food, the veil papillae may warn the nudibranch of a potential predator. When the animal crawls, the veil papil- lae are held upward and forward. As soon as they con- tact anything unfamiliar or different from the immediate surroundings, the animal retracts and then cautiously extends itself, exploring the area with the veil papillae. If it is unpleasant, the nudibranch will turn away. If, however, it is food, Dendronotus advances immediately and begins to feed. In all the local species which feed on hydroids, there are some indications that the lip papillae Page 438 are used to orient the mouth and lips parallel to the long axis of the hydroid stalk. The jaws may then be effectively employed in holding the stalk while the radula rasps through the perisarc, and the animal can withdraw the coenosarc easily. The most important taxonomic features of the head region (Figures 1 to 3) are the number, degree of branching, and arrangement of the veil and lip papillae. The color of the lips is also distinctive in some cases. No attempt was made to describe the inner labial ring and other mouth armature described by MacFar.Lanp (1966). The veil papillae have been arbitrarily defined as those papillae which originate in a single row from the most distal edge of the more or less distinct, horseshoe-shaped veil. The lip papillae are all those papillae in the ventral cephalic region not included in the above. In some species, such as Dendronotus rufus, the lip papillae may be as long as the shorter veil papillae and more branched, but their position establishes their relationship. The lip pa- pillae may be arranged in vaguely regular rows. It must be emphasized that this definition of the papillae may be artificial as it is based on position, not function. To facilitate identification of any particular pair of veil papillae they are numbered from medial to lateral, the medial pair being pair no. 1 (Figures 2, 3). Jaws The jaws of Dendronotus, enclosing most of the buccal mass, provide attachment for the jaw and radula muscles. The functional portion of the jaw is the masticatory pro- cess which is responsible for holding the prey and possibly chops off pieces of the prey as it is pulled into the mouth by the radula. Inferences about the species’ feeding habits may be made from the structure of the jaw and its size relative to the size of the animal. The descriptions and diagrams (Figures 5, 7, 10, 13, 16, 19, 22, 25) attempt to point out differences in shape and relative proportions of the jaw components. With the ex- ception of Dendronotus iris, the jaws are fairly uniform morphologically within the genus and one must exercise caution in attempting to identify the species of Dendro- notus from the jaws alone. For a fairly complete description and excellent drawings of the jaws of some species of Dendronotus, the reader is referred to MacFarLanp (1966). He includes a detailed description of the denticulation on the masticatory border of the jaw, but I feel that this is not a particularly useful taxonomic character, partly because of the difficulty in examining the denticles, and partly because of the con- siderable intraspecific variation and interspecific overlap in number and shape. THE VELIGER Vol. 12; No. 4 Figure 5 Measurements and components of a Dendronotus jaw A. Inside lateral view B. Dorsal view ANT=anterior BJ=body of jaw © DP=dorsal process of jaw H = height HI = hinge of jaw L = length MB = masticatory border MP = masticatory process POST = posterior W = width Radula The radula of nudibranchs (Figures 8, 11, 14, 17, 20, 23, 26), as in most other mollusks, serves as a rasping organ which, operated by a complicated series of muscles, moves back and forth over the odontophore pulling food into the pharynx. However, descriptions of the radular muscula- ture and other functional considerations of the buccal mass are left for future work. ; Because the basic shape of the median and lateral teeth is essentially the same in all the species, the reader is referred to MacFarianp (1966) for a relatively detailed descripion of these teeth in 4 species. The width-height ratio for the median tooth (see Figure 6 for measurements) referred to in this paper is not the same as that of Gar- sTanc (1890), MacFartanp (1966) or O’DoNnocHUE (1921); it was used because of the ease with which it could be measured. This ratio usually decreases, some- Vol. 12; No. 4 times markedly, from the anterior, well-worn teeth to the posterior, unused teeth. The denticulation and number of the median and later- al teeth of the radula are taxonomically important. For purposes of this paper, the lateral teeth in a transverse row are numbered from medial to lateral, number 1 being Figure 6 Measurements and components of a generalized Dendronotus radula H = height LTC = lateral tooth cusp LTD = lateral tooth denticle MTD = median tooth denticle W = width adjacent to the median tooth. The rows are numbered from oldest to newest, number 1 row being the oldest. The denticulation is a striking feature of the radula of Dendronotus. Along the cutting edge of the triangular cusp of the median tooth, there may be: a few relatively large, sharp denticles; many small denticles giving a serrulated appearance; no denticles at all; or any combi- nation of these three. These denticles may be limited to the proximal half of the cusp or they may extend along its whole length, in which case the denticles generally decrease in size towards the apex of the cusp. The denticles of the lateral teeth are limited to the outer margin of the sharp, curved cusp although they and the cusp are usually absent from the innermost teeth. These denticles vary in size, number, and shape, but there is an intraspecific con- sistency and interspecific dissimilarity which aids in classi- fying these nudibranchs. Reproductive System Dendronotus has a triaulic genital system (Figures 9, 12. 15, 18, 21, 24, 27, 28) with the penis completely separate and the “female portion split longitudinally in an uterine and a vaginal portion which communicate proximally and distally’ (OpHNER, 1936, p. 1071; see also Exior, 1910; THE VELIGER Page 439 GHISELIN, 1965). No attempt was made to determine the exact relationships and functions of the various struc- tures in this triaulic system, but the following scheme, based on reports on related genera and families (GHISELIN, op. cit.; ODHNER, op. cit.; THompson, 1961) is probably reasonably accurate. The hermaphrodite gland or ovotestis, composed of numerous tightly packed round to pyriform lobules, pro- duces both ova and sperm. The central rounded follicle contains developing spermatogonia and mature sperm, while the developing ova surround these male follicles (MacFar.anp, 1966). A thin tube arises from this lobule to join others, eventually forming the hermaprodite duct through which gametes course to the ampulla where the sperm are stored prior to copulation (GHISELIN, 1965, p. 331). There is some evidence that the sperm are produced first and, after copulation, are stored in the seminal receptacle of the partner until the ova ripen (GHISELIN, op. cit., p. 343; but see also THompson, 1961, p. 10). There is a short spermoviduct joining the am- pulla to the bifurcation that leads to the vas deferens and the oviduct. Possibly there is a valve at this bifur- cation that functions much the same way as it does in Tritonta hombergi to separate endogenous gametes and send them along the proper ducts (THompson, op. cit.). The sperm travel along a short duct, the proximal portion of the vas deferens, leading to the prostate por- tion of the vas deferens. The function of the prostate, composed of varying numbers of large or small glandular alveoli, or both, is poorly known (GHISELIN, op. cit., p. 331). ODHNER’s suggestion (1936, p. 1070) that the extern- al appearance of the prostate may be species specific has been verified in this study. The distal portion of the vas deferens, which probably secretes some of the prostatic secretions, continues from the prostate to the penis. This distal portion may be short and thick (Dendronotus dalli, Figure 15) or it may be long and tortuous (D. rufus, Fig- ure 18). It continues to the penis tip as the convoluted, ta- pered ejaculatory duct. The unarmed penis, enclosed within a preputium opening to the outside, varies con- siderably in size and shape. The female system begins at the bifurcation of the spermoviduct as the oviduct. This leads to the fertiliza- tion chamber and_ subsequent parts; “albumin gland,’ membrane gland, and mucous gland (GHISELIN, op. cit., p. 334). Just before the oviduct enters the fertilization chamber, an insemination duct, which subsequently dilates to form the seminal receptacle, arises. From the seminal receptacle, the vagina courses to the common female cavity or vestibule into which the “female gland mass” also opens. Near the opening of the vagina, there is a small bursa copulatrix which may Page 440 not be functional (GHISELIN, op. cit., p. 334; ODHNER, op. cit., p. 1107). Copulation in Dendronotus seems to be reciprocal, the penis of each partner being inserted into the vagina of the other. At present, the exact place where the sperm is deposited is an enigma, but the length of that portion of the penis that is inserted into the partner suggests that it is in the seminal receptacle. The exogenous sperm is prob- ably stored in the seminal receptacle (as indicated above) where it may be rendered physiologically active by secre- tions from the epithelium (THompson, op. cit.). From here, it travels to the fertilization chamber, via the insem- ination duct, to fertilize the endogenous ova. The zygote follows a predetermined path through the “female gland mass” where the primary egg capsules, nidamental layers, and other necessary mucus coats are added prior to ovipo- sition (GuiseLIn, 1965; THompson, 1961). The egg masses are Type B (Hurst, 1967). Geographical Distribution At present, the distribution records for the species of Dendronotus suggest that the genus is restricted to the north temperate and arctic seas. With the exception of one record of D. albus from Islas Los Coronados, Mexico (Lance, pers. comm.), none have been described from the sub-tropical or tropical seas. So far, the only record from the seas of the southern hemisphere is 2 small specimens of D. gracilis (Miller, pers. comm.). This type of distribution is possibly directly related to the collection effort, but it may represent an actual biological phenomenon caused by so far unknown causes. Further investigations would be desirable to clarify this situation. As far as possible, all geographical areas where a species of Dendronotus has been found are recorded. The records for D. frondosus are extensive and have been condensed. Ecology No species description should be considered complete un- less some indication of the species’ life history and ecology is given. Yet, very little has been published concerning the ecology of Dendronotus. The food preference of D. fron- dosus has been briefly mentioned by a few authors (MIL- LER, 1961; SWENNEN, 1961; THompson, 1964; Waters, 1966). Hurst (1967), MacFartanp (1966), MILLER (1962), Swennen (1961), and others report briefly on various aspects of the reproductive biology of D. frondos- us. There are numerous rather extensive reports on the geographical distribution of Dendronotus (Brercu, 1894; Marcus, 1961; Opuner, 1926) giving collection sites and occasionally depth. However, no description is given THE VELIGER Vol. 12; No. 4 of the hydrography or of the substratum, and both are important in understanding the ecology of the nudibranch. More complete ecological studies will be the subject of another paper, but the data presented here indicate trends and are useful both for taxonomic purposes and as a guide for further ecological studies. The physical data collected include depth, current action, and composition of the bottom (rock, mud, shell-gravel, etc.). The imme- diate substratum (hydroid, rock, etc.) of the animal at the time of collection plus the presence (or absence) and abundance of potential food items is noted. Some aspects of the reproductive biology such as copu- lation in the field and laboratory, and degree of gonadal development are recorded. In some cases, a description of the egg string, its location in the field, and length of time from oviposition to hatching of the veliger is presented. Brief descriptions are made of the feeding processes where seen or where reported. A more detailed report of these processes will be the subject of a future publication. Comments concerning the possibility of cryptic or warn- ing coloration as well as some methods of defense against, or escape from, predators are made where appropriate. Dendronotacea This name was first used by OpHNER (1934) to include a number of families and genera (OpHNER, 1936). This suborder is characterized partly by the structure of the liver but, more importantly, by the fact that the clavus of the rhinophore is retractable into the rhinophore sheath (Extot, 1910; Opuner, 1934, 1936) and by the branched cerata on the notum. The latter are found in all the species of the Dendronotacea to a greater or lesser degree. DENDRONOTIDAE Dendronotus ALDER & HANcock, 1845 At present, the family has only one genus, Dendronotus. On the basis of a reduced branching of the cerata, crown papillae, and veil papillae compared to Dendronotus (EI- ot, 1910), Bercu (1863) established the genus Campaspe to include the species C. pusilla and later, C. major BeRGH, 1886. Evior (1910) and OpHNeER (1936) conclude that BrErGH was actually describing juvenile specimens of D. frondosus. ODHNER (op. cit., p. 1105) states that: “Since the genus Campaspe BERcH 1863, to which BErcH referred two species established by himself; cannot be sepa- rated from Dendronotus and is based on juvenile specimens of D. frondosus ..., the family includes [a] single member the genus Dendronotus.” Vol. 12; No. 4 Those features characterizing the genus also necessarily apply to the monotypic family. The following compendium of characters has been compiled from the family or genus diagnoses of Exior (1910), OpHNER (1936), PRruvor- Fou (1954), Turere (1929-35). Body limaciform; 4 - 8 pairs of arborescent cerata, one of each pair on either side of the dorsum; cerata lacking cnidosacs and any special gill (present in the Dotonidae) ; relatively distinct veil supporting 2-5 pairs of more or less branched veil papillae; clavus of rhinophore perfoli- ate with 8 - 30 leaves; top of rhinophore sheath extended as 4-6 more or less branched crown papillae; a lateral papilla originating from the lateral border of the rhino- phore stalk; anal papilla between first and second cerata on the right side; genital openings anterior and ventral to base of the first ceras on the right side; liver in 3 parts, one large posterior portion and 2 smaller anterior portions; hepatic diverticula may extend into some or all of the cerata and rhinophores; no stomachal plates; salivary gland long; relatively strong jaws; radula narrow to moderately wide (6-1-6 to 21-1-21); median teeth with smooth or denticulated cusp; lateral teeth narrow, point- ed, usually denticulated; triaulic genital system; prostate present; bursa copulatrix small; penis unarmed. Dendronotus frondosus (ASCANIUS, 1774) (Plate 63, Figure 29; Text figures 4, 7, 8, 9) Amphitrite frondosa Ascantus, 1774, K. Norske Vidensk. Sels- skabs Skrifter, Deel 5: 155; plt. 5, fig. 2 Doris arborescens MULLER, 1776, Zoologiae Danicae Prodro- mus, p. 229 Doris cervina GMeEuin, 1791, Syst. Nat. per Regna Tria Nat., 13" ed., 1 (6): 3105, no. 12 Tritonia arborescens Cuvier, 1817, Ann. Mus. 6: 434; plt. 6, figs. 8- 10 Tritonia reynoldsii CourHouy, 1838, Boston Journ. Nat. Hist. 2 (1): 74; plt. 2, figs. 1-4 Tritonia lactea THompson, 1840, Ann. Nat. Hist. 5: 88; plt. 2, fig. 3 Tritonia pulchella ALDER & Hancock, 1842, Ann. Mag. Nat. Hist. 9: 33 Dendronotus arborescens (MULLER, 1776). ALDER « Hancock, 1845, Ray Soc. Monogr., Fam. 3, plt. 3, prt. 1 Am phitritidea fabricti “Beck 1847.” Morcu, Grénland (Rink) (Prodr. Fauna Moll. Gronl., p. 6), 1857; in synonymy [this reference has been taken directly from TREDALE & O’DonocHuE, 1923] Dendronotus luteolus LaFont, 1871, Act. Soc. Linn. Bor- deaux, 28: 287; plt. 17, fig. 1 Dendronotus purpureus BercH, 1879, Proc. Acad. Nat. Sci. Philadelphia, art. 5: 145 - 150; pit. 1, figs. 18 - 20; plt. 3, figs. 7 - 12 THE VELIGER Page 441 Dendronotus purpureus var. aurantiaca FriELE, 1879, Jahrb. Deutsch. Malakozool. Gesellsch. 6: (page unknown) [reference unavailable] Campaspe pusilla Bercu, 1863, Naturh. Tidsskr., 3 R., 1: 471-478; plt. 12, figs. 28 - 35 Campaspe major Bercu, 1886, Bidjr. Dierk. 13: 21 - 24; plt. 1, figs. 23 - 26; plt. 2, figs. 1 - 11 Dendronotus frondosus (Ascantus, 1774). Plymouth Marine Invert. Fauna 1904. Journ. Marine Biol. Assoc. U. K. 7: 282 Dendronotus lacteus (THompson, 1840). Extor, 1910, Ray Soc. Monogr. Suppl., Fam. 2, genus 1, p. 161 Dendronotus venustus MacFarLanp, 1966, Mem. Calif. Acad. Sci. 6: 271 - 275; plt. 40, fig. 2; plt. 46, figs. 9 - 12; plt. 47, figs. 1-2; plt. 49, fig. 6; plt. 50, fig. 3; plt. 52, figs. 3-6 Taxonomic Remarks The above references are only part of a fairly extensive, and often conflicting, literature concerned mainly with taxonomy, morphology, and geographical distribution of Dendronotus frondosus. The description by Ascanius (1774) is sufficient to establish that Amphitrite frondosa is the same animal as Doris arborescens Mi.iER, 1776. Thus the name Amphi- trite frondosa takes priority. However, the generic name is unavailable because it is used by O. F MUxier in 1771 for a genus of polychaetes. Because A. frondosa is not the type species for either the genus Doris or Tritonia, nor is it a member of either of these genera, the species must be placed in the next available genus, Dendronotus, estab- lished by ALDER & Hancock (1845). They distinguished Dendronotus from Tritonia on the basis of rhinophore structure, the lack of a sub-pallial ridge on the dorsum, free arborescent cerata, and the structure of the liver. However, they used the species name arborescens appar- ently unaware of the existence of frondosa. The first time Dendronotus frondosus was used appears to be in the Plymouth Marine Invertebrate Fauna (1904). Probably Euiot was responsible for this change (see Exiot, 1910) although no reference is made to him. Subsequent authors have used both D. frondosus and D. arborescens, but the correct name is Dendronotus frondosus (Ascantus, 1774). Biologists of the 18 and 19% centuries added to the confusion by describing a number of “new species” (Dend- ronotus luteolus, D. purpureus, D. lacteus) as well as a “new genus,’ Campaspe. All of these are almost surely synonyms of D. frondosus. OpuHNER (1936) used Dendronotus frondosus as a catch-all for all the previously described species except D. robustus and D. iris. He maintained that D. frondosus was a highly polymorphic species and that the other de- scribed species were well within the limits of variability Page 442 to be expected from this polymorphic species (see under D. dalli and D. rufus for further discussion) . Dendronotus venustus represents a case of splitting. Except for color, this species is very similar to D. fron- dosus. I have collected a few specimens which, in color, intergrade between these two nominal species, particularly with reference to the white patches found between the cerata by MacFartanp. In his field notes (deposited at the California Academy of Sciences), MacFarLanp de- scribes color phases of D. venustus which are identical with D. frondosus. Lance (pers. comm.) is also of the opinion that D. venustus is a synonym of D. frondosus. The descriptions of Dendronotus frondosus by Marcus (1961) and MacFartanp (1966) confuse 3 or 4, and 3, distinct species, respectively. Body Dimensiens, Texture, and Apertures The limaciform, laterally compressed body is moderately “heavy.” The rounded dorsum tapers posteriorly to a long, sharply pointed tail and merges laterally with the vertical sides. The largest animal collected was 4.2 cm L while the largest reported are 5.5-6.0cm (BERGH, 1879, 1894), 9.8cm L (SwENNEN, 1961), and 11.5cm L (MacGinimE, 1959). The smallest animal I collected was 0.2cm L. Most, however, have been 1.0 - 3.0cm L with only a few being longer than 3.5 cm. The anus is borne on a distinct papilla, often capped with a yellow pigment, and located halfway between the first and second right cerata. The genital apertures open externally about 3 of the way up the right side of the body, just anterior to the base of the first ceras. The cardiac prominence is large and often rises 4-5 mm higher than the dorsum. The body is covered with bluntly conical papillae of various sizes that are usually tallest on the cardiac prominence. A distinctive charac- teristic of this species is the yellow or white pigment that caps these papillae; only rarely is it missing. Foot The long, relatively narrow foot is bluntly rounded ante- riorly and tapers to a short, pointed tail. The sole is white and translucent. The edge of the foot flares along its entire length when the animal is crawling on a smooth surface. It is able to adhere more firmly than other species to smooth surfaces. When on a hydroid, the edges of the foot wrap around the stalk allowing the nudibranch to adhere firmly to the hydroid. THE VELIGER Vol. 12; No. 4 Color The translucent, gray-white ground color of the animal is overlaid with varying concentrations of brown, red-brown, yellow, and white pigments in assorted patterns (Plate 63, Figure 29). To the naked eye, some of the animals have a reddish-brown hue, streaked and marbled with brown and spotted with yellow and white while others are very pale tan with numerous yellow spots. A few, particularly those from deeper water (more than 25m), lack all pigment and appear white. In about 50% of the animals, the body was brown with a sparse scattering of white and yellow spots, but the distal portions of all the body processes were devoid of brown and appeared transparent or yellowish. A few animals were devoid of light pigments, while a few others were devoid of any brown but were liberally covered with yel- low or white or both (see ALDER & HANcock for colora- tion and pattern). The pinkish-brown hepatic diverticula and liver are clearly visible through the body wall as is the white hermaphrodite gland. Cerata The 5-7 (4-8) pairs of tall, erect cerata are arranged at posteriorly decreasing intervals. The height and degree of branching also decreases posteriorly. In a few speci- mens, there are | - 4 small, unbranched, unpaired cerata on the posterior end. The cerata are more arborescent than in the new species of Dendronotus, but less so than in D. rufus or D. iris. The main branches, quite tall and slender, give rise to numerous relatively long secondary and tertiary branches that end in pointed transparent tips. The pattern of main branches is typically “fan-shaped” (Figure 4a) with 3 main branches in the first 3 pairs, 2 - 3 in the 4" pair, 1 - 2 in the 5", and one in the rest. In those pairs with 3 main branches, the medial is the tallest while no. 2 branch is about # as long and arises just above the lateral. The lateral branch, arising right at the base of the ceras, is about 4 to 2 as long as the medial and diminishes in size from the anterior to the posterior cerata. The hepatic diverticula appear to be present in the anterior 4-5 pairs of cerata, usually in the medial 1 - 2 main branches as well as the rhinophores. These divertic- ula in the first pair of cerata and the rhinophores originate from the anterior lobes of the liver and the rest arise from the posterior lobe. Vol. 12; No. 4 THE VELIGER Page 443 Rhinophore and Clavus The moderately branched rhinophore is about equal in height to the first pair of cerata. The lateral papilla, arising between a quarter and half way up the stalk, is relatively long, often extending as high as or higher than the clavus. The degree of branching is variable; some are simple papillae, most have a few short, simple secondary branches, and a few are very branched, much like the cerata. The sub-conical perfoliate clavus bears 8 - 12 shallow- cut leaves that alternate in width. There are a few reports of up to 20 - 25 leaves in larger animals (Bercu, 1894, 1900) and I have seen as few as 5 - 6 in smaller ones. The coloration of the clavus is similar to that of the rest of the body. There are usually 5 (4-6) long, stout crown papillae having little or no secondary branching. The postero-me- dial papilla may be 1-3 as long as the 3 anterior papillae which are usually about equal in length. The postero-lateral may be about twice as long as the anterior ones. Head, Lips, and Veil In size, number, and branching, the veil papillae seem to come midway between the condition found in Dendro- notus rufus and D. dalli, and that of D. albus. There are 4 pairs of relatively stout, branched veil papillae. On the larger pairs, the branching may be ex- tensive, much like the cerata, or it may be confined to a few small papillae. The smaller pairs are often unbranched, sometimes have a few small papillae, or, rarely, they may be extensively branched. The medial pair (no. 1) is the longest, no. 2 is the shortest at about } to 4 as long, no. 3 is slightly shorter than no. 1, and no. 4 is about 3 as long as no. 1. There are 2-4 (0-8) long, thin, simple lip papillae located lateral and posterior to the plicated lips. These papillae are sensitive to touch and retract almost com- pletely when stimulated mechanically. Jaws The body of the jaw (Figure 7) is a translucent dingy- yellow which becomes dark brown, almost black on the masticatory process, hinge, and proximal portion of the dorsal process. The body is a shallowly convex, almost oblong structure about 24> as long as wide with a mod- erately convex posterior end. The slightly curved, rather wide dorsal process is in- clined posteriorly at 55° - 60° from the long axis of the Figure 7 Dendronotus frondosus jaw B. Ventral view C. Outside lateral view D. Inside lateral view A. Dorsal view body. It is about 0.41 as long as the body of the jaw and has a shallow dorsal groove. A thin, strongly convex lateral expansion joins the proximal 3 of the process to the body. The moderately long, curved masticatory pro- cess, often sharply hooked at the free end, is joined by an almost flat, strong expansion to the body. A small number of relatively large, black denticles adorns the masticatory margin. Radula The radula (Figure 8), described a number of times (AtpEeR &« Hancock, 1845; Bercu, 1879, 1894, 1900; Meyer « MoOsius, 1865; O’DonocHuE, 1921), varies widely in the number of rows of teeth present, but this appears to be directly correlated with the length of the animal. The radula formula, from the literature, is 29 -49(7 - 14:1-7-14) and from those I examined (10 specimens), it is 33-48(7-11-1-7-11). Bercu (1894) and VoLopcHENKOo (1955) report that they found golden- yellow teeth in their specimens, but all those I examined were colorless. The cusp of the median tooth, about 1.4 - 1.7 as wide as high, comes to a relatively sharp point. There are 7 to 15 large, strong, sharp denticles on the sides of the cusp, usually becoming smaller towards the apex. In the ante- rior teeth, there are fewer denticles and they tend to Page 444 disappear near the apex while the posterior teeth have more denticles extending along the whole side. The lateral edge of the denticles continues down the dorsal side of the cusp as a deep furrow. The elongate, relatively wide lateral teeth bear long, curved cusps inclined 10° to 20° toward the midline. They are usually rather longer than shown in Figure 8. Figure 8 Dendronotus frondosus radula Rows 25 to 27 in a radula with 45 rows of teeth On the innermost 1 - 3 teeth, the cusp is often no longer than the denticles while in the outermost 1 - 2, the cusp may be missing or rudimentary. The size is about equal in the rest. From anterior to posterior, within a single radula, the cusps tend to become longer and fewer are broken off. All the teeth, except the outer 1-2, bear 2-5 (0-7) long, strong, sharp, regularly spaced denticles on the lateral margin of the cusp. Reproductive System The large, white hermaphrodite gland gives rise to a long hermaphrodite duct that widens suddenly into a wide ampulla curled up like a doughnut (Figure 9). The long, narrow spermoviduct arises from the other end of the ampulla but runs alongside the hermaphrodite duct for a short distance. The proximal portion of the vas defer- ens and the oviduct are both short, translucent and quite narrow. OpHNER (1936) reports -and figures the prostate as being “. . . a circular disc composed of numerous scattered vesiculae [= alveoli] (fig. 39a), in many circles ...” THE VELIGER Vol. 12; No. 4 Figure 9 Reproductive system of Dendronotus frondosus (exploded view) AMP = ampulla BC = bursa copulatrix DVD = distal vas deferens FC = fertilization chamber FGA = female genital aperture FGM = (to) female gland mass HD = hermaphrodite duct ID = insemination duct OV = oviduct P= preputium PE = penis PR = prostate PVD = proximal vas deferens SO = spermoviduct SR = seminal receptacle VA = vagina VE = vestibule However, I rarely saw more than 12 and usually only 5 - 8 large, ovoid alveoli arranged as a disc concentric with the vas deferens. From the prostate arises a very narrow, long, convoluted, almost untapered distal portion of the vas deferens. It enters the penis to become a much con- voluted ejaculatory duct. The very long, thin penis, tapered to a point and coiled up in the preputium, has a pleated base. The long, convoluted vagina empties into the large, sessile, pear-shaped seminal receptacle. The distal end of the vagina opens into the vestibule quite near the external orifice. A small, stalked bursa copulatrix is located about 3 of the length of the vagina away from the vestibule. The insemination duct is moderately long and convoluted. The reproductive system described and figured by Mac- FarLanp (1966) for Dendronotus venustus agrees closely with that of D. frondosus, further evidence that D. ven- ustus should be considered a synonym of D. frondosus. Geographical Distribution Dendronotus frondosus, a north circumpolar species, has been reported from Arctic seas and the northern Atlantic and Pacific Oceans. More exact locations include the coast of Norway (OpHNER, 1926, 1939), Point Barrow, Vol. 12; No. 4 THE VELIGER Page 445 the Bering Sea, the east coast of North America from Labrador to Cape Cod, Greenland, the Faroes, the Shet- lands, Spitzbergen, and the western Arctic (MacGint- TIE, 1959), the eastern Atlantic south to the Bay of Biscay (Bercu, 1894), and the Baltic Sea as far as Kiel Bay (SwENNEN, 1961). It has also been found on the northern Asiatic coast (Basa, 1957; VoLopcHENKO, 1955) and along the Eastern Pacific Coast from Alaska to Southern California (Lance, pers. comm.; unpublished observation). Kerry Clark (pers. comm.) has collected a number of specimens from the coast of Connecticut. Ecology Despite the number of descriptions of the species, there has been surprisingly little published about its biology. Brief mention has been made of its food and substratum preferences, and the reproductive cycle (Murtter, 1961, 1962; SweNNEN, 1961; THompson, 1964; WarTERs, 1966). Locally, the species has been collected from April to the beginning of December from floating wharves in Friday Harbor and from June to March in the sub-tidal down to 40m. SwENNEN (1961) reports finding Dendronotus frondosus all year long at Den Helder. Other reports (Miter, 1962) would indicate D. frondosus are probab- ly present as adults, in greater or lesser numbers, through- out the year. Mr. K. Clark (pers. comm.) has found spe- cimens in May, but not in summer, in Connecticut. Dendronotus frondosus ranges from the inter-tidal to 400m-+ (SwENNEN, 1961) and is present on rocky as well as muddy bottoms and styrofoam floats, where numerous hydroid colonies are present. Dendronotus frondosus appears to be a feeding spe- cialist on hydroids, but is flexible about what species it will eat. It has been reported to feed on Tubularia indivi- sa and Sertularia cupressina (SWENNEN, 1961), Syn- coryne eximia, Bougainuillia glorietta, and Obelia com- missuralis (WaTERS, 1966), Tuwbularia larynx (BRAAMS & GEELEN, 1953), Dynamena pumila, Hydrallmania falcata and Sertularia argentea (Mituer, 1961),and Tubu- laria crocea (K. Clark, pers. comm.). There is also some evidence that the younger animals prefer one species of hydroid while the adults prefer another (SwENNEN, op. cit.). Noting this, MiLter (1961, p. 105) says: “... small specimens (1- 18mm) of Dendronotus frondosus feed on both gymnoblastic and calyptoblastic hydroids, large specimens (14-100mm) only on gymnoblasts (Tubularia spp.). The large polyps of Tubularia probably provide a fairly large volume of food in a form which can be grazed easily and rapidly, supplying a quantity sufficient for the needs of such a large nudibranch.” However, preliminary laboratory and field observations (Waters, 1966; author’s unpublished data) suggest that this is not so locally and that adult D. frondosus prefer thecate hydroids like Obelia to athecates like Tubularia. The mechanism of feeding has been briefly described (Waters, 1966), and some additional information has since been obtained, particularly pertaining to predation on Obelia commissuralis, When the veil and lip papillae come in contact with a hydranth, the nudibranch imme- diately retracts these structures, and then begins to search about for the prey. This withdrawal, presumably in res- ponse to the nematocysts of the hydranth, may occur 2 to 3 times, but eventually the animal envelops the whole hydranth and, using the jaws and radula, chops it off. Occasionally the nudibranch will attack just proximal to the hydranth. In this case, it uses the same method as when the coenosarc is eaten (WATERS, op. cit.). The nudibranch appears to use the outer lips and lip papillae to align the body and opening of the jaws parallel to the stalk. Achieving this, it grips the perisarc firmly with the outer lips, the jaws are protruded, and working trans- versely to the stem’s long axis, they cut a hole in the perisarc. The radula is apparently extended through this hole and proceeds to rasp out the coenosarc (or the hydranth). In a relatively short time, one nudibranch is able to clean out a large hydroid colony. There are conflicting reports about the reproductive activity of the species. SWENNEN (1961)reports it as being sexually mature all year except February and No- vember, and spawning from April to August and again in January. Locally, spawn and mature animals were seen from April to October. Clark (pers. comm.) found egg masses during early May in Connecticut. THomPsoNn (1964) and Mitter (1962) indicate that Dendronotus frondosus may live for 2 years, breeding in both years. They also suggest that there may be more than one generation a year, but SWENNEN (op. cit.) feels that most only live one year. It is possible that a few animals do live for 2 years, not having spawned the first year, but most probably mate, spawn, and die within a year. The nidosome is described by Hurst (1967, p. 264) as “... an untidy coil varying from pale to dark pink.” I have also seen a number of white ones in relatively neat coils. There was usually only one egg per capsule, and the eggs took from 13 to 16 days to hatch. It is hard to say how cryptic the coloration of this nudibranch is because the background may be so variable. On hydroids, it would likely not show even in its lighter brown color forms although the white, deepwater ani- mals are quite visible to a diver. There are no other obvious means of defense although it may have some Page 446 epidermal secretions (THomMpson, 1960b; Epmunps, 1966). Dendronotus frondosus is an able swimmer, but the actual distance covered is usually small unless a current is present. Mechanical stimuli such as poking or pinching with forceps are effective in eliciting the swimming be- havior. So far, no potential predator has been demon- strated to elicit swimming although VoLopCHENKO (1955) reports that this species is preyed upon by fish. Dendronotus iris Cooper, 1863 (Plate 63, Figure 30; Text figures 4 - 6, 10 - 12) Dendronotus iris Cooper, 1863, Proc. Calif. Acad. Nat. Sci. 3: 59 Dendronotus giganteus O’DoNocHuE, 1921, Trans. Roy. Ca- nad. Inst. 13 (1): 187 - 190; plt. 4, fig. 47; plt. 5, figs. 57 - 59 Taxonomic Remarks Coorper’s brief description, based on color, is adequate to establish Dendronotus iris as a valid species name. He states (p. 59) that “this species seems more variable in color than other nudibranchiata of this coast, but I [see] no reason for considering [it] more than one species” and indicates that a slight color variation of it may be found in Puget Sound. O’DonocHuE (1921) recognizes that color is quite vari- able in the nudibranchs, even between Nanaimo, B. C. and California, but he neglects this when he describes Dendronotus giganteus. He makes no reference to Coo- PER’S paper. OpHNER (1936, pp. 1107 - 1108) recognized O’Dono- GHUE'’ error and declared Dendronotus giganteus a syno- nym of D. iris. Subsequent authors, with the exception of SmitH « Gorpon (1948), have retained D. iris as the proper name. Body Dimensions, Texture, and Apertures The limaciform body, the “heaviest” of all the local species of Dendonotus, tapers abruptly to a bluntly pointed tail. A well-rounded dorsum merges into vertical sides, the only demarcation being the 2 rows of cerata. The largest animal found was 29.0cm L & 6.4cm H < 8.9cm W and displaced 1100 cc of water. O’Dono- GHUE (1921) claims a preserved specimen, measuring 21.0cm L & 8.4cm H X5.5cm W, may have been 26cm L < 10.0cm H & 6.5cm W when alive. Most of the animals (many preserved) were 6.5 - 12.0 (3.0- 29.0) cm L X 1.5-2.0 (0.5-5.0) cm H X 1.0-2.2 (0.5-4.0) cm THE VELIGER Vol. 12; No. 4 W.A few representative animals were: 8.0cm L & 1.5cm H X 1.5cm W (live); 65cm L X .1.5cm H X'1.0cm W (live); 9.0cem L & 3.5cmH X 2.5 cm W (preserved); 3.0cm L X0.5cm HX 0.5cm W (preserved). The anus is on a distinct, truncate papilla located half way along the imaginary line joining the bases of the first and second right cerata. Often, an opaque white line marks the edge of the papilla and the plicated lips, surrounding the anal opening, are usually white. The distinct genital openings are located about 2 the way up the right side, below or immediately anterior to the base of the first right ceras. Sometimes, an opaque white line marks the edge of the genital openings. Very often, in preserved specimens, the penis is extruded. The cardiac prominence is usually not visible except as a very slight bulge. The body was smooth in all the specimens examined. Foot The long, quite wide foot is bluntly rounded anteriorly and terminates in a short, bluntly-rounded tail. When crawling, the foot often flares out considerably beyond the plane of the sides of the body, contrary to what MacFar- LAND (1966, p. 258) says. In one 8cm L animal, the foot was flared out 1.5cm on either side, giving the foot a total width of 5.5 cm. A useful, but not infallible, diagnostic character of the species is the narrow, opaque, dead-white line that edges the dorsal margin of the foot. The sole is white in the “gray” forms and a light orange in the “orange-red” forms. The expansiveness of the foot may be an adaptation to crawling across the soft muddy bottom that this species inhabits, the greater surface area allowing for a better grip on the unstable substratum. It is almost non-func- tional as a grasping organ, and apparently is non-func- tional in helping the animal to maintain its position in a fast current (which it probably encounters only rarely in nature). Color Most specimens (23 of 30) were of the “gray” form, while 7 were of the “orange-red” form. In the “gray” form, the ground color varies from a clean, translucent, gray-white through yellow-brown to a dark muddy brown (Plate 63, Figure 30). The ground color is lightest on the sides, becoming darker on the dorsum and bases of the dorsal processes (cerata and rhinophores) and very dark towards the distal ends of the cerata, crown papillae, lateral papillae, and veil papillae. At the ends of the Vol. 12; No. 4 THE VELIGER Page 447 smaller branches of these processes is a variety of colors: metallic orange (1 animal), dark purple (11 animals), a mixture of chrome-yellow and purple (9 animals) with small amounts of white found in most animals. In the “orange-red” forms, the ground color is a beauti- ful “orange-red.” Again, this becomes darker on the cera- ta, rhinophores and veil papillae, but finally gives way, at the ends of the appendages, to purple (2 animals), metallic orange (3 animals), or a mixture of the two (2 animals). Only one animal had the white tips on the cerata with a sub-terminal orange ring described by Cooper (1863). All the intergradations between the two main color forms exist. The lip papillae are normally tipped with chrome yel- low or are unpigmented, but 2 specimens had metallic orange in place of the yellow. Cerata There are 4-6 (3-8) pairs of stout, but very tall and dendriform cerata, the last pair being about half as tall as the first. Arranged at decreasing intervals on the dorso- lateral margins of the body, they begin about 4 of the way back from the anterior end. Nearly all the specimens have 2 (1-4) small, branched, unpaired papillae on the posterior end. The cerata are not firm and erect as they are in the less dendritic forms, but are instead quite supple and extensible. Because of these traits, and the fact that they are usually badly mutilated in the dredge hauls, it is often difficult to determine the number of main branches in a ceras. The very thick, basal portion of the ceras divides al- most immediately to give rise to a number of tall, thick main branches arranged in a “fan-shaped” pattern (Fig- ure 4a). There are 3 (2-5) main branches in the first pair (no. 1), 3 (2-4) inno, 2, 2-3 inno. 3, 2 (1-3) in no. 4, 1 (1-3) inno. 5, 1 (0-2) inno. 6, and 1 in nos. 7 and 8. These subdivide into secondary branches that may be nearly as long as the main ones while the tertiary branches are only slightly shorter. The secondary and tertiary branches end in small, delicate tufts, giving the animal a very bushy appearance when viewed from above. The medial branch is the longest (up to 5-7cm ina 15cm L animal) while the lateral is the shortest. According to MacFarLanp (1966) only the first pair of cerata and the rhinophores have “ceratal cores” or hepatic diverticula, arising from the anterior lobes of the liver. OpHNER (1936) states that the diverticula are ramified throughout the cerata as shown by ALDER & Hancock (1845), but neglects to mention in how many pairs this occurs. In 10 animals examined, I always found the situation described by MacFarLanp. Rhinophore and Clavus The rhinophore resembles the cerata with its very thick stalk and the extensive branching of the lateral and crown papillae. At the base, the lateral papilla is thick but it soon divides into a number of smaller secondary branches which in turn branch and terminate in small, delicate tufts. Arranged vertically on the posterior border of the rhinophore stalk are 4 (2-6) small, branched papillae found only in this species. The inconspicuous, muddy brown, conical clavus is per- foliated with about 25 (15-31) leaves alternating in breadth. The top 2 - 4 and bottom 4 - 6 leaves are usually small and equal. Those inbetween alternate more or less regularly with the wider leaves almost completely cover- ing the narrower ones. The 5 (2-5) crown papillae are relatively longer and more branched than in most species except Dendronotus rufus. The branching is not as neat as in D. rufus but tends to occur at any point from the base to the tip, making it hard to ascertain the actual number of crown papillae in many cases. The postero-medial is the longest, being 2-4 longer than the 3 almost equal, anterior papillae. The postero-lateral may be from 1} - 3 longer than the anterior papillae. Head, Lips, and Veil On the indistinct veil, there are almost always 3 (2 - 4) pairs of stout veil papillae varying considerably in size and degree of branching. However, they are generally sparsely branched and short, relative to the animal’s size. Contrary to what MacFartanp (1966) shows in his drawing compiled from a number of specimens, I found that the medial pair was usually smallest and the lateral pair (no. 3) the largest (from 14 0 2 longer than no. 1). Pair no. 3 is divided almost from the base into a smaller, sparsely branched lateral ramus and a much longer (2), more branched medial ramus. Often, the veil papillae were all very small and simple, making them indistinguishable from the lip papillae except by position. There are many lip papillae (20-40, depending on the size of the specimen) arranged in 3 - 4 irregularly cres- centic rows around the mouth and lips. The most anterior row, immediately ventral to the veil papillae, consists of 6 (5-8) simple to slightly branched papillae about equal in length to the shortest veil papillae. In the second row, there are 7 (6-12) simple papillae about 4 to 2 Page 448 the size of the preceding ones. The most ventral “row” of 10-25 small, simple papillae and tubercles is very irregularly arranged around the mouth. Jaws The jaws of Dendronotus iris (Figure 10) are the largest and heaviest seen in any of the local species of Dendro- notus. In the whole genus, only D. robustus may have heavier, albeit relatively shorter, jaws. MacFarLANnp (1966) found in a 9.1cm L preserved specimen that the jaws were 1.72cm L X 0.75cm W (see Figure 5 for measurements ). In 5 specimens that I examined, the sizes were: Dendronotus iris length of animal _lengthof jaw height of jaw _—- width of jaw (measurements in centimeters) 13.0 2.8 0.95 0.85 7.0 1.5 0.65 8.0 1.6 0.65 10.0 1.8 0.70 4.0 1.1 0.35 The total length of the animal body is only about 5X that of the jaw. Figure 10 Dendronotus iris jaw B. Ventral view C. Inside lateral view D. Outside lateral view A. Dorsal view The jaws are a deep reddish brown on the masticatory process and hinge, fading to a light yellow along the dorsal process and body. The masticatory denticles may be almost black. The body of the jaw is an elongate, mytiloid shape, widest at the posterior end. The length of the body is slightly less than 3 the maximum width which occurs in the posterior third. The strong dorsal process, weakly curved, is inclined posteriorly at about 40° to the longi- THE VELIGER Vol. 12; No. 4 tudinal axis of the body, and is joined to the body by a strong, convex expansion for over half of the length of the process. The dorsal process is about a third (or slightly more) as long as the body. The strong, arched mastica- tory process is joined to the body by another thick, but weakly concave expansion. There are about 85 - 100 large denticles on the masticatory border. A feature not seen in any other Dendronotus is the very long, convoluted esophagus. Its function is not known at present, although it may be related to the fact that the animal can extrude the whole buccal mass through the lips when feeding (moribund animals usually extrude the “proboscis’’) . For a more complete description of the jaw, the reader is referred to MacFarLanp (1966, pp. 259 - 260). Radula The radula (Figure 11) is most unlike that of any other Dendronotus. The radula formula, according to MacFar- LAND (1966) and O’DonocHUE (1921) is: 34-46 (11-20-1-11-20) and 35-40 (12 - 16- 1-12-16), respectively. In 9 specimens, I found it to be: 41-61 (11-21-1-11-21), giving a maximum range of seal (uilozil eile hil Bil). The tall sharp-pointed cusp of the medial tooth is only slightly higher than wide (Figure 6) and bears on the concave margins 11 (9-18) strongly developed, pointed denticles. These denticles, more prominent than in any other species, are slightly concave on the medial edge. The lateral margin of the denticle continues anteriorly on the tooth as a deep furrow. Toward the apex of the cusp, particularly on teeth from the posterior half of the radula, the denticles decrease in size, number, and regularity. For example, in one radula with 58 teeth, there were 7 large, regularly spaced denticles on the first medial tooth, Figure 11 Dendronotus iris radula Rows 22 to 24 in a radula with 43 rows of teeth Vol. 12; No. 4 THE VELIGER Page 449 9 on the 25", 12 on the 35" and only 8 irregular ones on the 524. The lateral teeth become more numerous from the oldest rows to the youngest. The oldest 1 - 3 rows have no lateral teeth, rows 2-5 have 3-10 teeth, and by about row 8, the main battery of teeth is present with only 1 - 3 more to be added toward the posterior end. Usually, there are no denticles on the laterals but occasionally, the no. 1 tooth in the first 10 - 15 rows will be serrulated or even bear 1 - 8 short, sharp denticles. Rarely, the no. 2 lateral in the first few rows will also be serrulated or bear a few tiny denticles. The typical lateral tooth consists of a flat, elongated base upon which there is a gently tapering, blunt-pointed, stout cusp inclined at about 20° toward the midline of the radula. The outermost 3 - 4 lateral teeth decrease in size, the most lateral one being a narrow, flat plate with a short spine. The innermost lateral has a rod-like base that terminates in a short, stout cusp. Reproductive System The thin hermaphrodite duct joins the large, white, lob- ulated hermaphrodite gland to the very long, tortuous ampulla which is relatively the longest found in the genus (Figure 12). The ampulla merges indistinctly with the spermoviduct which bifurcates, giving rise to a short prox- imal portion of the vas deferens and relatively long, thin-walled, almost transparent oviduct. The prostate is made up of alveoli surrounding and con- cealing more than # of the total length of the looped vas deferens. The short, narrow, muscular distal portion of the vas deferens enters the base of the penis where it con- tinues as the coiled ejaculatory duct. The long penis, sheathed in a relatively thick-walled preputium, is very thick throughout its whole length; it is the largest in the genus. The short, wide, muscular vagina terminates in an in- distinct, somewhat irregularly shaped seminal receptacle. Located on the distal third of the vagina is the bursa cop- ulatrix atop a very long, thin stalk. A long, convoluted insemination duct, much narrower than the vagina, joins the seminal receptacle to the fertilization chamber via the oviduct. OpuHNER (1936, figure 40), in a poor diagram of the Dendronotus iris genital system, has misplaced the in- semination duct, a continuation of what he calls the vesi- cula seminalis (v.s.), and the spermoviduct, a continua- tion of what he calls the ampulla (f.). The spermoviduct should terminate between the prostate and the insemina- tion duct. AMP 1.0 cm HD | Figure 12 Reproductive system of Dendronotus iris (exploded view) AMP = ampulla BG = bursa copulatrix DVD = distal vas deferens ED = ejaculatory duct FC = fertilization chamber FGA = female genital aperture FGM = (to) female gland mass HD = hermaphrodite duct ID = insemination duct OV = oviduct P = preputium PE = penis PR = prostate PVD = proximal vas deferens SO = spermoviduct SR = seminal receptacle VA = vagina VE = vestibule Geographical Distribution Dendronotus iris has usually been collected subtidally from 7 m at Nanaimo, B. C. to about 200 m off Unalaska in the Aleutian Islands. The southern limit at present is the Coronados Islands in Mexico (Lance, pers. comm.). It has been recorded from Nanaimo, B. C. (O’DonocHUE, 1921) ; the Queen Charlotte Islands, B. C. (D. B. Quayle, pers. comm.) ; Puget Sound (Cooprr, 1863) ; and numer- ous areas in Califomia (SmirH « Gorpon, 1948; G.E. MacGinitie, pers. comm.). AGERSBorG (1922) reports one from the shore of Shaw Island and another from logs near the Puget Sound Biological Station, both in the San Juan Archipelago. Page 450 Ecology This species has been obtained by dredging in a number of places around the San Juan Islands (see Materials and Methods, above) where it is apparently present year round. I collected 15 more while SCUBA diving at Na- naimo. The animals are almost always collected from muddy bottoms where there is little current action. This type of bottom often supports a dense population of Cerianthus sp., the burrowing anthozoan that is the principal food of Dendronotus iris; in fact, the available evidence would suggest that it is the sole food of this nudibranch. Dendronotus iris displays a specialized feeding behavior. How it locates the Cerianthus is unknown, but, upon con- tact with the anemone’s tube (which extends as much as 15 cm above the substratum), D. iris begins to crawl up the tube. The veil papillae are extended and the head moves slowly back and forth through about a 120° arc. When D. iris contacts a Cerianthus tentacle, the nudi- branch immediately withdraws. Again the veil papillae are extended and the head moves back and forth in ever decreasing arcs until D. iris has “homed in” on the ten- tacle. Dendronotus iris then lifts the anterior third of the body free of the tube, lunges forward, at the same time extruding the buccal mass through and past the mouth. The Cerianthus tentacles are grasped with the jaws and chopped off whole by the radula. This attack must be and is done rapidly as the Cerianthus is able to withdraw quickly. Withdrawal seems to be a poor defense; smaller D. tris apparently can climb down the tube or are pulled down the tube when the attacked Cerianthus retracts. I have found whole, undigested Cerianthus tentacles in the stomachs of many specimens as well as multitudes of nematocysts in the intestine and fecal pellets; no other prey species were found. MacFartanp (1922) reports finding fragments of a nemertean in one animal. AcERS- BORG (1922) tried to feed many things to a Dendronotus giganteus (= D. iris), but it was only interested in the tentacles from an unnamed coelenterate which were mouthed, but not eaten. Very little information is available concerning reproduc- tion in Dendronotus iris. In the laboratory, between Feb- ruary 7 and 13, 1967, 3 white egg masses were deposited in a large rounded bundle. There were 45 - 50 and 31 - 40 eggs per capsule. The veligers hatched after 13-15, 16, and 17 days from the 3 egg masses. In June, 1967, 3 more egg masses with up to 100 eggs per capsule were laid by 3 very large animals (28.7, 25.4, and 20.3cm L). The same animals were copulating and laying eggs when collected at Clarke Rock, Nanaimo. In June, 1968, 8 egg masses were seen on the tubes of Cerianthus sp. at the Monterey Breakwater, Monterey, California. THE VELIGER Vol. 12; No. 4 There is some suggestion that this species, particularly the gray form, is cryptic in its natural habitat although first-hand observation indicates that it can be spotted fairly easily by a diver. Predators, probably fish, must occasionally detect Dendronotus iris, either by sight or smell, and attempt to eat the nudibranch. Evidence for this is found in the numerous D. iris collected with parts of the dorsal appendages missing. The cerata (or portions thereof) are rather easily broken off with rough handling. Upon severance, these parts move quite naturally and even “swim” to some degree. This may be a protective measure, serving as a decoy while the nudibranch makes its escape. AcErspore (1922) states that Dendronotus iris is a very capable swimmer and suggests that it is basically pe- lagic, creeping on the bottom only occasionally. I suggest that the opposite is more likely in view of the extensive development and size of the foot as a creeping organ, and the nudibranch’s food preference. It swims quite readily in the laboratory or field when disturbed, and has occa- sionally been seen to swim with no apparent provocation. The swimming appears to be directed upwards, presum- ably away from disturbing factors on the bottom. That this swimming is very effective is supported by the sight- ings of animals on the surface over 130m of water and about half a mile from shore in Saanich Inlet. Dendronotus robustus VERRILL, 1870 Dendronotus robustus VERRILL, 1870, Amer. Journ. Sci. Arts 50: 405 - 406; fig. 1 Dendronotus velifer Sars, 1878, Bidr. Kundsk. Norg. Arktisk. Fauna, pp. 238 - 239, plt. 28, fig. 2 Taxonomic Remarks There has been little doubt expressed by previous authors (Bercu, 1894; OpHNER, 1936) that Dendronotus robust- us is a distinct and valid species. VERRILL’s description is complete enough to prevent confusion and for this reason it is difficult to understand why Sars (1878) redescribed it under a different name. I have seen no living or preserved material of this species, so the description is compiled from the literature, using the two above references plus BercH (1894). These descriptions are not very complete nor are they specific in detail. Body Dimensions, Texture, and Apertures The body is stouter, less compressed laterally and less acutely tapered posteriorly than is Dendronotus frondosus (see plate 28, fig. 2 in Sars, 1878). The largest animal Vol. 12; No. 4 observed was about 9cm long (Bercu, 1894), but measured ones were 2.5cmL X 1.25cm W &X 1.25cmH (live) (VeErRRILL, 1870) and2.8cmL x 1.0cmH 0.95 cm W (preserved) (BEeRcH, 1894). Verritt (1879, 1882) claims to have found some larger animals, but he gives no dimensions. The anus, atop the anal papilla, is located nearer the second right ceras than is true for other species. The genital openings are “as usual” (Bercu, 1894). Apparently there is no cardiac prominence. BERcH (1894) notes that the body is smooth, but Sars’ figures (1878) show a scattering of small tubercles all over the dorsal surface. Foot The foot is as wide as the body (VERRILL, 1870) and small objects like hydroids can apparently be grasped by infolding the edge of the foot. Color VerrILL (1870) claims the animal is a pale grayish ground color liberally sprinkled with small yellow spots except on the veil papillae and rhinophore stalk where there are only a few spots. Sars (1878) and Brercu (1894) mention a reddish body seeded with white spots. All the lip and veil papillae are tipped with a sulphur yellow (VERRILL, op. cit.). Cerata There are 6-7 pairs of relatively short, stout cerata. They are not exceptionally arborescent, most of the branching being only short, thick offshoots. In the first to third pairs of cerata, the main lateral branch arises inde- pendently of and lateral to the base of the other main branches. In pairs 4 and 5, the lateral branch arises from the base of the ceras, while all the posterior pairs are only single stalks. Rhinophore and Clavus There is no lateral papilla on the stout, round rhinophore stalk. The perfoliate clavus, with 10 - 12 (VeRrRILL, 1870) or 15 - 20 (Bercu, 1894) leaves is surrounded by 5 simple, round, smooth, tapering crown papillae of which the pos- terior 2 are the longest. Head, Lips, and Veil The head is covered over by an enormous veil, upon which there are 8-10 veil papillae. The outer two on THE VELIGER Page 451 each side are the largest by about 2, but they are all knob-like with short, simple branches on the ventral side. About 10 small, unequally sized lip papillae adorn each side of the lips. Some are forked, but most are simple. Jaws The jaw, relatively shorter than is common for Dendro- notus, is also thicker and heavier than is usual for the genus. No other information or diagrams have been pub- lished. Radula The radula formula is 29 - 35(15 - 21:1-15- 21). Bercu (1894) states that the median teeth of the radula are horn yellow while the lateral teeth are colorless. The median tooth is strongly denticulated, especially proximally, with 15 - 20 sharp denticles that become shor- ter towards the tip of the cusp (see plt. 2, figs. 7 - 9, Bercy, 1894). The hook of the lateral tooth becomes longer and more curved from the inside toward the middle and then begins to decrease in size as the outermost teeth are approached. The innermost tooth (no. 1) has no denticles and virtually no cusp. Teeth no. 2 - 4 have 1 - 2 strong denticles at the base of the cusp. Most of the other laterals, save the outer 1-3, have 3-5 smaller denticles at the base of the long cusp although the denticulation is irregular and often absent. The outermost laterals are without denticles and have only a small cusp. Reproductive System There is virtually no description of this system in the literature. ODHNER (1936) mentions that the seminal re- ceptacle is a pouch-like structure off the proximal end of the vagina and that the prostate is a single ring of about 11 vesicles. Geographical Distribution So far, this species has only been found in the Arctic and Atlantic Oceans, and has been reported from Spitzbergen, Greenland, Siberia, northern Norway (OpHNER, 1926) and from Cape Cod to Nova Scotia (VERRILL, 1879). Ecology There are no published data concerning any aspect of ecology except that Dendronous robustus occurs from the intertidal down to at least 200m (OpHNER, 1939). Page 452 THE VELIGER Vol. 12; No. 4 Dendronotus dalli BErcH, 1879 (Plate 63, Figure 31; Text figures 1, 4 - 6, 13 - 15) Dendronotus dalli BERGH, 1879, Proc. Acad. Nat. Sci. Phila- delphia 5(1): 150; plt. 1, fig. 21; plt. 2, figs. 9 - 12; plt. 3, figs. 2-6 Dendronotus elegans VERRILL, 1880, Proc. U.S. Nat. Mus. 3: 385 - 386 Dendronotus frondosus (Ascanius, 1774). OpHNER, 1936, Mém. Musée Roy. Hist. Nat. Belg., ser. 2, 12 (3): 1105 - 1109 Taxonomic Remarks Bercy (1879) first described Dendronotus dalli from a “bulbus pharyngeus’”’ or buccal mass dredged in the Bering Strait. The main points of difference from D. frondosus, he felt, were the complete lack of denticulation on the median tooth and the more distinct denticles on the masti- catory border of the jaw. In a later paper that included a more extensive descrip- tion of a whole animal, BercH (1894) expressed some doubt about the validity of Dendronotus dalli. He indi- cated that it, like D. purpureus, may be a color variety of D. frondosus that lacks all the median tooth denticulation. However, he retained the name D. dalli in a still later description of a specimen collected at Bear Island (BERGH, 1900). O’DonocHvE (1921) gave a brief description of the external characters of a small specimen. However, this description, with the exception of the larger number of lateral teeth, fits Dendronotus spec. nov. almost exactly. O’DonocHUE deposited the specimens, upon which he based his description, in the museum at the Nanaimo Biological Station, but during a subsequent move, they were apparently lost (Clarke, pers. comm.; Quayle, pers. comm.). OpHNER (1936) expressed some doubt about O’Dono- GHUE'’s description and concluded that, without more spe- cific and detailed information, Dendronotus dalli should be considered a synonym of D. frondosus. He dismissed all of Bercu’s work by stating that the radula characters upon which Bereu based his descriptions are too variable for taxonomic purposes (ODHNER, 1926, 1936). MacFar- LAND (1966, p. 257), in agreeing with OpHNER, stated: “He [O’DonocHUvE] gives no anatomical details to support his conclusion [that Dendronotus dalli is a distinct species], and until these are produced, the conclusion of OpHNER (1936) that the radula characteristics are too variable to justify spe- cies discrimination are most reasonable.” VERRILL’s (1880) description of Dendronotus elegans strongly suggests that the animal was a D. dalli and not a morphological variant of D. frondosus as ODHNER (1936) suggests. Because there are no further records pub- lished by VERRILL, I suggest, on the basis of this descrip- tion, that D. elegans be considered a synonym of D. dalli. The following description shows that Dendronotus dalli is indeed a valid species, distinct morphologically and bio- logically from D. frondosus. Body Dimensions, Texture, and Apertures In the relatively heavy, laterally compressed, limaciform body, the rounded dorsum merges indistinctly with the vertical sides. The posterior third of the body tapers to form a short, moderately blunt-pointed tail (Figure 1). The largest specimen was 13.5 cm L and there were 11 others over 9.0cm L. Most of the animals were 4.0 - 6.0 (1.9- 13.5) em L X 0.7- 1.5 (0.6 - 3.1) cmH x 0.5 - 1.0 (0.4 - 1.6) cm W. A few representative measurements of live animals were: 4.4cm L < 0.7cm H X 0.5cm W;; 65cm L & 1.2cmH X 0.9cm W; 8.0cm L & 1.5cm H x 1.2cm W. Bercu (1879, 1894) estimates one ani- mal to be 10 cm L while others were 3.5 cm and 4.2 cm L, both preserved. O’DonocHuE’s (1921) largest speci- men, preserved, was 3.1cm L & 0.9cm H X 0.6cm W. VoLopcHENKO (1955) reports specimens up to 10 cm L. The anal papilla, if present, is inconspicuously located halfway beween the bases of no. 1 and no. 2 right cerata. The conspicuous genital openings are located about halfway up the right side of the body, just anterior to the first ceras. The cardiac prominence is usually only a slight eleva- tion, but in a few specimens it is protruded up to 4 - 5 mm above the dorsum. Only 2 of 60 animals had any body papillae and these were limited to the cardiac prominence. All the other animals were smooth. Explanation of Plate 63 Figure 29: Dendronotus frondosus (AscANius), white form from 20 m off San Juan Island, Washington X 2 Figure 30: Dendronotus iris Cooper, grey form. In this particular animal, the grey is overlaid with the muddy brown pigment com- monly seen on animals from deep-water muddy bottoms x 4 Figure 31: Dendronotus dalli Brercu. Note the relatively short, stout, but extensively branched cerata (CE) and veil papillae (VP) x1 Figure 32: Dendronotus rufus O’DonocHuE. Note the tall, ex- tensively branched cerata (CE) and rhinophores (RH). The magenta pigment is less dense on the veil papillae (VP) and rhinophores X 4 THE VELIGER, Vol. 12, No. 4 [RopILLiARp] Plate 63 Figure 29 Figure 32 Figure 31 Figure 30 me ir Vol. 12; No. 4 Foot The foot (Figure 1) is about 4 as wide as long. The anterior end is blunt and rounded while the posterior end tapers abruptly to a blunt point. When the animal is crawling, the foot flares laterally along its whole length though not as extensively as in Dendronotus iris. During swimming, the edges fold quite tightly together. The sole of the foot is white or very pale pink with a faint hint of darker pink around the edges; this edging is not as prominent as it is in D. iris or D. rufus. Despite the large size of the foot, the animal is capable of clinging stubbornly to the stiff branches of the hydroids, Abietinaria rigida or A. amphora. It is able to maintain its position on plain rock in the face of a relatively fast current. Color Previously, all the descriptions have been of preserved specimens which become a dull, indifferent gray in alcohol or formalin. In life, Dendronotus dalli is rather uniformly colored in varying shades of translucent white through pearl pink to salmon pink; 3 specimens were a mauve hue. Most of the animals collected were pearl pink (Plate 63, Figure 31). The color is lightest on the sides, becoming darker on the dorsum and darkest on the cerata, rhino- phores, and veil papillae. The extremities of these proces- ses are usually covered with an opaque, dead-white pig- ment, occasionally extending down the main branches in irregular lines of scattered patches. A few animals were sparsely to liberally sprinkled with tiny, opaque, white spots. The clavus and oral region (outer lips and lip papillae) are a yellowish color. The tan to dark pink liver and the white gonad are plainly visible through the body wall. Cerata The short, but extensively branched cerata are in 6-7 (4-8) pairs arranged at intervals along the dorso-lateral margin of the body. VoLopcHENKo (1955) reports up to 9 pairs. Both the interval and size of the cerata gradually decrease from anterior to posterior. On the tail, there are 1 - 2 (1-5) unpaired, but often relatively large, branched processes or “accessory cerata.” These occasionally occur between the other cerata also. The main branches are quite stout, but short; often the total height of the cerata is not much more than the height of the body. The main branches give rise to even shorter, stout secondary branches which in turn may divide into small tertiary branches. These secondary and tertiary branches, because they are short and arise from THE VELIGER Page 453 all sides of the main branches, impart a “fuzzy” appear- ance to the cerata. When viewed from above, the ceratal mat provides very little cover for the dorsum. The branching pattern is “fan-shaped” (Figure 4a) with 4 (3-4) main branches in no. 1 cerata, 3 - 4 in no. 2, 3 (2-4) in no. 3, 3 (2-3) in no. 4, 2-3 in no. 5, 2 (1-2) in no. 6, and 1 in nos. 7 and 8. Where there are 4 main branches, there is a dichotomy at or very near the base of the ceras. Each of these stalks divides almost im- mediately to form 4 branches. The medial branch is short, the next one out (no. 2) is the longest, no. 3 is about equal to no. 2 and the lateral branch (no. 4) is shortest, being about 4 to 4 as long as no. 3. Where there are 3 main branches, the lateral branch (no. 3) arises at or near the base of the ceras above which the ceras bifurcates to form branches no. 1 and no. 2. The medial branch is the longest, but no. 2 is only slightly shorter while the lateral is again about 4 to 4 as long as no. 1. If there are only 2 main branches, they divide at the base and no. 2 is vari- able in length. In some large specimens, there is an extra medial branch in the first pair of cerata. The cerata of Dendronotus dalli appear to be subject to many aberrations in size and branching. This may be the result of attacks by predators, probably fish. Rhinophore and Clavus The rhinophore, like the cerata, is relatively short and stout with many small branches. The lateral papilla, arising from or near the base of the rhinophore stalk, is heavy and long, often reaching higher than the extended clavus. The degree of branching varies a good deal from a few small, simple papillae arising from the main branch to the extensive secondary and tertiary branching comparable to the cerata. The yellow, perfoliate clavus has 20-24 (16-33) roughly alternating, shallow-cut leaves. The top 3 - 4 and bottom 2 - 3 leaves are small and equal. The large leaves almost completely encircle the clavus while the small ones are limited to the posterior border. Extending upward from the rhinophore sheath are 5 (4-12) highly variable crown papillae. They are usually long, but not particularly stout. All are about equal in length though the posterior two may be 2 longer than the others, and often as tall as the rhinophore stalk itself. The branching consists of a few relatively short papillae arising from the proximal half of the main stalk. Head, Lips, and Veil The veil, not sharply marked off from the head, bears 4 or, more often, 5 pairs of stout, extensively branched veil Page 454 papillae radiating fan-like from it (Figure 1). The ar- rangement and size of the veil papillae varies, making it difficult to count and describe them. In those animals with 4 pairs of papillae, the medial pair (no. 1) is usually the longest, no. 2 is about 4 to 3 as long as no. 1, no. 3 is about equal to no. 1, and no. 4 is the shortest at a } to 4 the length of no. 1. When 5 pairs are present, no. 1 is the longest. No. 2 pair may be + to ? as long and originates ventro-lateral to no. 1. Or, it may be about equal to no. 3 in size. Pairs no. 3 and no. 4 are usually about 4 to ¢ as long as no. 1. The unbranched lateral pair, no. 5, is about 4 to tas long as no. 1. In a few specimens all 4 or 5 pairs of veil papillae are approximately the same length. Many (15-30+) simple lip papillae, ranging in length from mere tubercles near the mouth to long, finger- like papillae on the lateral margins, adorn the oral surface (Figure 1). Some of the larger lip papillae, especially those just ventral to the veil papillae, may be forked at the tip or, rarely, they may be quite bushy. All the lip papillae are sensitive and able to retract when disturbed. Jaws The jaws of Dendronotus dalli (Figure 13) seem longer and stronger than they are. The buccal mass has a length : width ratio of 1.2 - 1.4 and a length : height ratio ofp Ibo) ae 7: The jaws are transparent, citron yellow, slightly darker on the hinge and masticatory process. In his original de- 1.0mm D Figure 13 Dendronotus dalli jaw B. Ventral view C. Inside lateral view D. Outside lateral view A. Dorsal view THE VELIGER Vol. 12; No. 4 scription, BercH (1879) incorrectly states that the jaw is darker than that of Dendronotus frondosus, but in sub- sequent papers (1894, 1900), he indirectly corrects this error. The body has a deeply convex, mytiloid form, widest in the posterior third and bluntly convex on the posterior end. The length : width ratio is about 2: 1 (Figure 5 for measurements). The large, strong, deeply grooved dorsal process, about 0.45 the jaw body length, is inclined at a 60° angle to the longitudinal axis of the jaw body. The process is joined to the body by a strongly convex ex- pansion for less than half of its length. The short masti- catory process, only slightly arched, bears about 200 low denticles (BrRcH, 1894) and is joined to the body by a thick, slightly concave expansion. Figure 14 Dendronotus dalli radula Row 21 in a radula with 38 rows of teeth Radula The radula (Figure 14), ODHNER’s (1926, 1936) com- ments notwithstanding, is distinctly different from that of Dendronotus frondosus. When the figures from all his descriptions are compiled, BercH (1879, 1894, 1900) reported a radula formula of 42 -51(11-16-1-11- 16) for D. dali. O.DoNocHUuE (1921) found it to be 38 - 40 (10-14-1-10-14). From a study of 29 radulae, I ob- tained a radula formula of 37-48 (9-14-1-9-14). The composite formula is 37-51 (9-16°1-9-16). Bercu (1894) stated that the median teeth are a dark mahogany color but I found only clear or very slightly yellow teeth in fresh specimens. f The cusp of the median tooth, rounded at the apex and weakly concave on the sides, becomes taller towards the radula sheath. In the oldest teeth the width : height ratio of the cusp is about 2:1, whereas from about row no. 20 on it is 1.7- 1.9: 1 (Figure 6 for measurements). As maintained by Bercu (1879, 1894) and O’DonoGHUE (1921), there are no conspicuous denticles on the median teeth. Except for a few cases, there is only an indistinct, Vol. 12; No. 4 THE VELIGER Page 455 irregular serrulation at most and this disappears toward the apex. A few specimens had 30-40 tiny, distinct, regularly arranged denticles on each side of the cusp, usually in the posterior half of the radula. The lateral teeth are long, narrow, flat plates increasing in size from anterior to posterior. The cusps of the lateral teeth are slightly inclined (about 10°) toward the midline and away from the long axis of the tooth’s base. On the innermost laterals, the cusp is about equal in length to the denticles. The next 2 - 4 teeth have large, sharp, weakly curved cusps bearing denticles along the proximal, lateral border. The sharp, thin cusps on the outer teeth decrease in length and finally disappear from the outer 1 - 2 teeth. Of the 9 - 14 lateral teeth in the specimens I examined, only the outer 2-3 (1-5) were without denticles. All the rest have 3 - 7 (1 - 19) sharp, irregularly arranged and shaped denticles that are long and heavy when there are only a few (1-6), but more slender when there are many (7- 11+). There is a tendency for the number of den- ticles to decrease from the inner to the outer teeth. On the inner two laterals (no. 1 and no. 2), there are respectively, 4-5 (2-11) and 4-6 (2-10) denticles. There are 4-6 (3-11) denticles on no. 3, 3-6 (2-10) on no. 4, 3-5 (2-8) onno. 5, 2-4 (1-8) onno. 6, 1-4 onno. 7, 1-3 on no. 8 and no. 9, and sometimes 1 or 2 small ones on no. 10. Numbers 8 to 10 occasionally lack any denticles. Reproductive System In Figure 15, the reproductive system is spread out to show the relative size and relationships of the component parts. Each lobule of the hermaphrodite gland seems to have a dark gray patch on the distal end. The hermaphrodite duct links the gland to the relatively long, narrow, coiled ampulla which merges indistinctly into the short, wide spermoviduct. The short proximal portion of the vas de- ferens expands into the prostate consisting of many small, usually spherical alveoli arranged as a flattened sphere concentric with the vas deferens. The wide, quite short and muscular distal portion of the vas deferens tapers very slightly before entering the penis. The penis is bullet- shaped, thick at the base and tapered to a point in the distal third. The short, wide vagina narrows slightly before entering the vestibule relatively far from the common female gen- ital opening. The small bursa copulatrix opens into the vagina near its distal opening. The seminal receptacle, a flattened ovoid structure that is bent back on itself, is located at the proximal end of the vagina. The insemi- nation duct appears to enter the vagina about halfway between the bursa copulatrix and the seminal receptacle, 1.0mm | HD Figure 15 Reproductive system of Dendronotus dalli (exploded view) AMP = ampulla BC = bursa copulatrix DVD = distal vas deferens ED = ejaculatory duct FC = (to) fertilization chamber FGA = female genital aperture FGM = (to) female gland mass HD = hermaphrodite duct ID = insemination duct OV = oviduct P = preputium PE = penis PR = prostate PVD = proximal vas deferens SO = spermoviduct SR = seminal receptacle VA = vagina VE = vestibule but closer inspection reveals that it continues as a tube within the lumen of the vagina and actually opens near the mouth of the seminal receptacle. The other end of the insemination duct is confluent with the short, transparent oviduct forming a fertilization chamber. Geographical Distribution Except for one specimen, this species has only been col- lected in the northeastern Pacific and the Bering Straits Page 456 at depths of 10 - 60 fathoms. Bercu (1879, 1894, 1900) had specimens from Bear Island in the Barents Sea (1), the North Pacific (2), and Bering Strait (1). O’Donoc- HUE (1921) collected them at Halibut Bank, Nanoose Bay, and Gabriola Pass, all off eastern Vancouver Island, B. C. VotopcHENKo (1955) mentioned them as occur- ring in the North Pacific off the Russian Coast. Besides the Victoria Breakwater (50 animals), I col- lected them from Albert Head, Victoria (3), Eagle Point (6), Lonesome Cove (5), Harney Channel (4 dredged), Turn Rock (3), and San Juan Channel (4). The latter 5 areas are in the San Juan Archipelago (see Appendix I). Ecology Up to now, nothing has been published concerning the ecology of this species. Adults, obtained from June, 1966 to April, 1967, were largest and most common from October to November, 1966 (although this may be a reflection of the collection pressure and timing). They were all collected at 20 - 30m from rocky areas supporting large populations of Abietin- aria rigida and A. amphora, but few other hydroids (with the exception of Lonesome Cove). These areas, often bordered by sandy or muddy bottoms, are usually swept by moderate currents. As mentioned above, Dend- ronotus dalli is able to cling to the hydroids despite these currents. During a dive off the Victoria Breakwater on August 10, 1966, large numbers of Dendronotus dalli egg masses were seen. White, loosely coiled, they were deposited on Abietinaria rigida, the rocks, and on other sessile animals such as Balanus nubilis and the bryozoan, Heteropora sp. During a second dive in late October, 1966, only a few egg masses were seen and in December, 1966 and January, 1968, there were none. One egg mass was collected from Eagle Point on March 27, 1967 and another from Turn Rock on January 21, 1968. The animals collected in December, 1966, when put in the water tables at the Friday Harbor Laboratories, began to copulate and deposit eggs all during January, 1967. It is difficult to tell whether this was a response to the change in light, temperature, salinity, or substratum; in any case, the gonads were mature when they were collected. A sample from some of these white to cream-colored egg masses contained 4-6, 2-3, 2-3, 3-4, 1-3, and 6-9 eggs per capsule. Hatching, in 4 cases, took 13-17, 15-18, 17 - 18, 18 - 19 days. To the human diver’s eye, these nudibranchs are visible up to 20 feet against the dark background of the rock and hydroid bed. Presumably fish are also able to see them THE VELIGER Vol. 12; No. 4 and, judging from the number of animals with mutilated cerata and rhinophores, probably attack them rather frequently. Dendronotus dalli is capable of effective, if not pro- longed swimming when it is disturbed. So far, only me- chanical stimuli such as pinching the cerata has proved effective in eliciting the response. None of the potential predators such as starfish, other carnivorous gastropods, or crabs have shown any effect although, in nature, the re- action to pinching seen in the laboratory may be an effec- tive escape response from a crab. No other methods of de- fense were obvious, but epidermal secretions are a possi- bility (EpMunps, 1966; THompson, 1960b). Dendronotus rufus O’DONOGHUE, 1921 (Plate 63, Figure 32; Text figures 4 - 6, 16 - 18) Dendronotus rufus O’DoNocHuE, 1921, Trans. Roy. Canad. Inst. 13 (1): 190 - 192; plt. 3, figs. 25 - 27; plt. 4, fig. 48 Dendronotus frondosus (Ascanius, 1774). OpHNER, 1936, Mém. Musée Roy. Hist. Nat. Belg., ser. 2, 12 (3): 1105 - 1109 Taxonomic Remarks O’DonocHUE, in describing this species, makes only brief and uncritical reference to the important taxonomic char- acters. It is little wonder that ODHNER (1936, p. 1108) said: “D. rufus ... has a colour which makes it a probable syn- onyme [sic] of D. frondosus, from which it cannot be separated (according to the description) in external characteristics.” Probably because of his belief that the radula characters in this genus are too variable to be of any use taxo- nomically, ODHNER says nothing about the differences, pointed out by O’DonocHuE, between the radula of Dendronotus rufus and D. frondosus. O’DonocHueE’s (1921) largest specimen was only 1.4 cm L while my smallest one was 7.0 cm L and the average was 17cm L. It is this size discrepancy that made it difficult to determine if the species described below is the same as that described by O’DonocHuE. The presence of a red line around the foot and the color of some of his specimens are the most important characters that link my specimens to Dendronotus rufus. The type specimen has apparently been lost (Quayle, pers. comm.; Clarke, pers. comm.; Tebble, pers. comm.), probably during a move of material from the Nanaimo Biological Station to the Canadian National Museum at Ottawa, Canada. Vol. 12; No. 4 THE VELIGER Page 457 Body Dimensions, Texture, and Apertures The limaciform body is relatively “heavy,” but not as stout in appearance as that of Dendronotus iris despite the generally larger size of D. rufus. The high, rounded dorsum is confluent with the vertical sides with no sign of a border except the cerata. The animal is laterally compressed, though not markedly so, and tapers to a short, blunt tail. As noted above, O’DoNocGHUE’s specimens were small, the largest being 14cm L & 0.45cm H X 04cm W and the smallest 0.6cm L. He subsequently collected a “fairly large” specimen, 1.65cm L & 0.52cm H X 0.36 cm W (O’DonocHuE, 1922, p. 164). The largest animal of 26 measured in this study was 28.0cm L & 4.5cm H < 4.2 cm W while the smallest was 7.0cm L & 1.5cm H x 1.0 cm W. Most of the animals were 15.0 - 20.7 (7.0 to 28.0) cm L X 3.0-4.0 (1.2-4.5) cmH X 2.5 - 3.0 (1.0 to 4.3) cm W. The anus is on a distinct papilla located about halfway between the first and second right cerata. The top of the papilla is usually magenta like the cerata. The genital apertures, located about halfway up the side and just anterior to the first ceras on the right, may be quite distinct, depending upon the sexual condition of the animal. The cardiac prominence is usually indistinct. The body may be smooth or it may have a few small, magenta- tipped, sub-conical papillae widely scattered on the dor- sum and the sides. Occasionally, it takes on a wrinkled appearance, particularly if the animal is at all contracted. Foot The foot, about 6 longer than wide, is bluntly rounded anteriorly, while the posterior end is bluntly pointed. The edge flares slightly when the animal is crawling on a smooth surface. The sole of the foot is white. Around the dorsal edge of the foot is a distinct light to dark magenta line made up of small pigment patches. In a few light-colored specimens, this line was not outstanding but it was discernible. In the 2 brick-red animals, this line was dark pink, but because of the body color, it was not so obvious. Observations in the field and in the laboratory indicate that this species is only partly successful in maintaining its position in a moderately strong current. It also appears unable to grasp the thin stalks of a hydroid, although, considering the size of the animal, this seems reasonable. As yet, nothing is known about the function of the foot in the juvenile stages. Color Because color is the important link between O’Donoc- HUE's description and mine, his original account is quoted in its entirety (O’DonocHuE, 1921, p. 190): “In the living animal, there is a considerable range of colour variation. The general body colour varies from a transparent grey through a semi-transparent pink to a deep brick red. In the grey form, the cerata were of a pale pink colour, in the pink form there was a narrow line of darker, more opaque pink, running around the edge of the foot and up around the head at the anterior end. A similar, but less marked darker line was also present in the red form.” All except 2 specimens that I examined had an opaque, gray-white ground color but, in a few, a liberal sprinkling of very fine magenta dots and some small, magenta-tipped papillae imparted a pinkish hue to the animal (Plate 63, Figure 32). Except in these few extensively pigmented animals, the gray-white color extends for varying distan- ces up the cerata, rhinophores, veil and lip papillae. It merges with a deep magenta pigment which becomes darker and more concentrated towards the distal ends of the above processes. In some animals, the magenta color becomes almost black. In others, it is washed out giving the appendages a distinctly yellow tinge under the ma- genta. The magenta line around the foot has been men- tioned above. Two specimens were of the “red form” mentioned by O’DonocuHvE (1921). The ground color is a deep brick- red, lightest on the sides, darker on the dorsum and bases of the appendages, and darkest on the distal portions of the appendages. Scattered over the body and appendages are many small, opaque, yellow to white spots. A few larger, pale cream patches were present on the sides just below the bases of the cerata. Between the cerata, there is an irregularly blotched line of large, opaque white pat- ches extending from the rhinophore to the tip of the tail. Cerata The cerata of this species are by far the largest and most dendritic of any of the species of Dendronotus. In an ani- mal 14.0 cm L, the tallest cerata were up to 8cm tall while the widest part of the “ceratal mat” was over 8 cm across. When viewed from above, the body of the animal is almost completely covered by the cerata. There are 7 - 8 (6-9) pairs of cerata placed at slightly decreasing intervals and followed by a single, unpaired ceras in a few animals. The cerata decrease in size also, the last pair being about 4 or less as tall as the first. Between the main cerata are found 4-11 “accessory cerata” varying in size from short, simple tufts to arbor- Page 458 escent branches nearly as large as the smaller cerata, and pigmented much like the cerata. Although most of them are irregularly placed, there are usually 2-4 in a trans- verse row across the cardiac prominence. The main branches of the cerata are thick, heavy, and very long. Originating from them are many long and relatively stout secondary branches which in turn divide into long, thin tertiary branches, or which terminate in a bushy tuft of fine filaments. The tertiary branches, fine as they are, often divide to form a smaller bushy tuft. The pattern of branching is “fan-shaped” (Figure 4a). There are 4 main branches in the first and second pairs of cerata, 3 - 4 in the third, 3 in the fourth, 3 (1-3) in the fifth, 2 (1 - 2) in the sixth, and 1 (1 - 2) in the seventh and eighth pairs. The main branches all split off the very short stalk at about the same level. The medial branch (no. 1) and no. 2 are about equal in size, while no. 3 is about # as large and no. 4 is about $ to 2 as large as no. 1. When 3 branches are present, the proportions are about the same but there is only one long medial instead of 2. Because of the great length of the secondary branches, it is very difficult to determine what to count as main branches and the choice becomes arbitrary especially in the anterior pairs. There is usually a large medial second- ary branch arising from the base of main branch no. 1 in the anterior 1 - 4 pairs of cerata. This and a smaller, lateral, secondary branch of main branch no. 4 (or no. 3) of the anterior pair(s) of cerata are particularly difficult to separate from the main branches. The hepatic diverticula extend into the rhinophores as well as the anterior 4 - 5 pairs of cerata which lie dorsal to the liver. These are visible only after dissection and are limited to the medial 2 - 3 branches of the ceras. O’DonocHuE (1921) described 5 pairs of cerata. The first 3 pairs had 3 simply branched trunks, the fourth pair had 2 simple main trunks, and the members of the fifth pair were simple projections. Rhinophore and Clavus The rhinophore, like the cerata, is extensively branched and very tall, reaching as high as the first pair of cerata. The heavy, firm lateral papilla originates from the base of the stout rhinophore stalk and, despite being at a 30° angle to the stalk, reaches as high as the clavus or even the top of the shorter crown papillae. From the main stalk spring many long secondary branches which may end in bushy tufts or may give rise to slender, tertiary branches that finally end in tufts. The sub-conical, yellowish to purple-spotted clavus is quite small relative to the size of the animal. There are 19 - 24 alternating shallow-cut leaves as opposed to the THE VELIGER Vol. 12; No. 4 8 - 10 non-alternating leaves mentioned by O’DoNoGHUE (1921). The upper 2 - 4 and lower 4 - 5 leaves are small and equal while on the rest of the clavus the large leaves are about 2 wider than the smaller, and almost com- pletely encircle the clavus. Radiating from the top of the sheath, like wheel spokes, the 5 crown papillae are long and stout. The branching, usually from the distal half of the papillae, may be re- stricted to a few relatively simple papillae and tufts or it may be more extensive albeit less so than on the other appendages. The crown papillae are all about equal in length; the longest, the postero-medial, is rarely more than 2 longer than the shortest. Occasionally, the 3 posterior ones are about 14 longer than the anterior 2. Head, Lips, and Veil The 5 pairs of veil papillae are made up of very dendritic, long, thick branches that radiate in an antero-dorsal plane at about 30° from the horizontal. The main branches divide into numerous secondary and tertiary branches just as already described for the cerata and lateral papillae. This type of branching makes it exceed- ingly difficult to determine what is and what is not a veil papilla. To make it even more difficult, the thick bases of the veil papillae arise immediately adjacent to each other. There is not even a gap in the midline between veil papillae from two sides as there is in the other species. The medial pair of veil papillae (no. 1) is the largest with no, 3 only slightly shorter. Number 2 pair, originating just ventral and lateral to the base of no. 1, is about } to 4 as long as no. 1. Pairs no. 4 and no. 5 are about equal to no. 2, though no. 5 is usually somewhat shorter. Immediately ventral to the veil papillae are 5-10 large, branched papillae that I have called “accessory lip papillae.” This name may seem incongruous consider- ing that these papillae are far larger and more branched than the other lip papillae, but they appear to function as veil, rather than lip, papillae; hence the term “acces- sory.” Posterior to these accessory lip papillae are the true lip papillae. There are 30 or more of these short to long, finger-like projections. A few of the anterior ones may be forked or slightly branched on top. Arranged in vaguely parallel rows coursing fore and aft on either side of the lips, they are longest laterally and shortest near the mouth. Jaws The jaws (Figure 16) and buccal mass of Dendronotus rufus are remarkably small for so large an animal. From Vol. 12; No. 4 THE VELIGER Page 459 a sample of 8 buccal masses, the length of the buccal mas was found to be about 1/20 to 1/25 the total length of the body. 1.0mm D Figure 16 Dendronotus rufus jaw B. Ventral view C. Inside lateral view D. Outside lateral view A. Dorsal view The light yellow jaws are relatively thin and delicate. The body is a moderately convex, mytiloid form, slightly wider in the posterior third and about 2.2 longer than wide. The dorsal process, about 0.45 < as long as the body and inclined at a 70° angle with its long axis, is joined to the body by a strongly convex expansion throughout half or more of its length. The distal portion of this broad, heavy dorsal process is curved downward and the dorsal groove is deeper and wider than in any other species. The masticatory process, at a 75° angle with the long axis of the body, is joined to the body by a strong, shal- lowly concave expansion and bears numerous rows of narrow, low denticles. Radula O’Donocnur (1921) described a radula formula of 32-35 (6-8-1-6-8): the laterals had 3-6 stout den- ticles while the medians bore 10 large sharp denticles. In contradistinction to this, in the 9 radulae that I examined, the formula was 33 - 35 (10 - 16:1-10- 16). The laterals have a variable number of short denticles, and the medi- ans bear many short, blunt denticles (Figure 17). If the animals O’DonoGHUE describes are juveniles of this spe- cies, then it seems that there must be a marked change in the radula characteristics during an individual’s life; it may be these transition stages which cause the confusion about which OpHNER (1926) writes. The cusp of the median tooth, rounded or bluntly pointed at the apex and very weakly bulged on the sides, is usually about 1.5 - 1.7 as wide as long, but in a few posterior teeth the ratio may increase to 2 (Figure 6 for measurements). The denticulation of the cusp varies considerably. There are commonly 16 - 22 (6-28) small, blunt, more or less regularly spaced, denticles diminishing in size towards the apex and sometimes disappearing al- together. The indentations of the proximal denticles con- tinue on the dorsal surface of the cusp as fine, shallow furrows, giving the tooth a delicately corrugated appear- ance. In a few specimens, there is only a fine serrulation along the edge while in a few others, the older teeth may be quite jagged where pieces have apparently been broken off. On any particular radula, the number of denticles on the median tooth generally increases from the oldest teeth to the newest. 0.1 mm — Figure 17 Dendronotus rufus radula Rows 21 and 22 in a radula with 36 rows of teeth Most of the tall, stout lateral teeth bear a strong, blunt- ly-pointed, straight cusp markedly inclined (20 - 30°) toward the midline. The inner few teeth have a distinct protuberance on the lateral border at the base of the cusp. In a transverse row, the cusp increases in size from a short, often insignificant quantity in teeth no. 1 and no. 2 to a maximum length in teeth no. 6 to 8 and then decreases again, often disappearing in the outermost | or 2 teeth. The denticulation of the lateral teeth is quite variable. Generally, the short, sharp denticles do not project very far above the lateral border of the cusp and then continue down the face of the base as relatively deep, distinct furrows. There is a vague tendency for the number of denticles per tooth to increase from anterior to posterior rows while within a row it is greatest at teeth nos. 4 - 7, and decreases on either side. The following list of denticle Page 460 numbers per lateral tooth is compiled from counts made on 6 rows at various points along the radula for 9 radulae. The numbers in parentheses represent extremes while those outside represent 70% of the teeth. Lateral Tooth (numbered Number of Denticles from medial to lateral) 1 none 50% of time; 1 - 4 otherwise 2 0-3 (0-5) 3 0-3 (0-6) 4 2-4 (0-6) 5 2-5 (0-7) 6 1-6 (0-8) 7 3-5 (0-9) 8 0-6 (0-9) 9 0-3 (0-8) 10 0-2 (0-7) 11 0-1 (0-6) . 12 0-1 (0-2) 13 0 14 0 15 0 Reproductive System The reproductive system (Figure 18) may be concisely described as “long.” The large, white hermaphrodite gland of sexually ma- ture animals appears gray in immature animals because of the small black spots on the lobules. The hermaphrodite duct expands suddenly to form a long, narrow ampulla, exceeded in relative length only by that of Dendronotus iris. The ampulla narrows rapidly to form the short sperm- oviduct that bifurcates to form a very short, transparent, rugose oviduct and an equally short proximal portion of the vas deferens. The vas deferens expands to form the prostate, a rela- tively enormous sphere concentric with the vas deferens and comprised of many small to large irregularly shaped alveoli. From this large prostate arises a very long, nar- row, extremely convoluted and coiled distal portion of the vas deferens. It tapers very gently throughout its whole length to become a thin tube. As such, it enters the base of the penis to form the long, convoluted ejaculatory duct. The long slender penis, coiled and folded back on itself in the preputium, is tapered to a slightly bulbous tip. The male portion of the Dendronotus rufus genital apparatus is most distinctive: the prostate is larger, the vas deferens is longer and more convoluted, and the penis is relatively longer and thinner than in any other species in the genus. THE VELIGER Vol. 12; No. 4 Figure 18 Reproductive system of Dendronotus rufus (exploded view) AMP = ampulla BC = bursa copulatrix DVD = distal vas deferens FC = (to) fertilization chamber FGA = female genital aperture FGM = (to) female gland mass HD = hermaphrodite duct ID = insemination duct OV = oviduct P = preputium PE = penis PR = prostate PVD = proximal vas deferens SO = spermoviduct SR = seminal receptacle VA =vagina VE = vestibule The long but narrow and tortuous vagina terminates proximally in a large, nearly sessile, ovoid seminal recept- acle. The bursa copulatrix, not much wider than its long stalk, is located near the opening of the vagina into the vestibule. A very short insemination duct is applied to the outer surface of the vagina for a short distance before joining the oviduct. Geographical Distribution O’DonocHuE (1921, 1922, 1924) collected Dendrono- tus rufus at Departure Bay, Nanoose Bay, Breadwater Island, and Thetis Island, all in the Strait of Georgia, B. C. The depth range was 20 - 40m. Vol. 12; No. 4 THE VELIGER The specimens collected for this study were obtained at Alki Point, Seattle (23 animals) from 15 - 17m; De- parture Bay, Nanaimo (1 animal) from 20m; Brown Island in Friday Harbor (1 animal) from 7m; and the floats at Jensen’s Boat Yard, Friday Harbor (2 animals). Ecology Juveniles of this species have not been seen, but adults were found from November, 1966 to March, 1967 and again from January to March, 1968. Dendronotus rufus seems to prefer areas of slight to moderate current action possibly because of the apparent inability to hold on in swift currents. The substratum has usually been rock sur- rounded on all sides by sand or mud or both. Examination of the fecal pellets plus observations in the field and laboratory indicate that scyphistomae, when present, form part of the diet of the Alki Point popula- tion of Dendronotus rufus. Nothing else was found in their guts except for a few amphipods that occurred on the scyphistomae. The fecal pellets of the animals collected at areas other than Alki Point contained no nematocysts or anything else recognizable. During late January, 1967, nudibranchs collected two months previously began depositing egg masses in the aquarium. Shortly after, on February 2, 7 egg masses were seen at Alki Point on the rocks and pipe. The animals collected then plus the previous group (16 in all) laid about 60 nidosomes up to the end of March when they all died. During January and February, 1968, about 100 copulating pairs were seen at Alki Point and 175 - 200 egg masses were deposited during February. By March 20, 1968, all the animals plus the egg masses were gone. In the field as well as the laboratory, the white to cream colored egg string was deposited in a regular though loose spiral. The number of eggs per capsule varied from 4 - 5 to 17 - 27, with an average of 13 - 17. The length of time from oviposition to hatching of the veligers varied from 13 - 20 days with most hatching in 15 - 18 days. Only because of its large size is Dendronotus rufus easy for a diver to see in the field. The dark cover provided by the cerata helps the animal to blend in with the back- ground, at least those upon which it has been seen. Dendronotus rufus appears to be a very poor swimmer responding quite slowly to strong mechanical stimulation. The species has a possible defense mechanism that the rest of the Dendronotus species lack: a thick, extremely sticky mucus. This mucus makes the animal slippery to hold, but, more important, it would probably “gum up” the mouth or claws of a predator due to its adhesive qualities. Predators may also find it repulsive to the taste. What- ever the particular defense mechanism, it must be effect- Page 461 ive for I have seen no mutilated specimens or evidence of attack as was so often seen in other species. Dendronotus gracilis BABA, 1949 Dendronotus gracilis Baba, 1949, Opisthobr. Sagami Bay, pp. 87 - 88, 167; fig. 109; plt. 35 Taxonomic Remarks To describe the internal and external structure and eco- logy of Dendronotus gracilis, 1 have used the description, text figures, and plates given by Basa (1949) supplement- ed by information from Dr. Michael Miller. Basa’s data have been rearranged to suit the format I have used in this paper. The radula of Dendronotus gracilis is not very different from that of D, albus or the new species, although that of the new species usually has more denticles on the lateral teeth. The number of cerata (4 pairs) and their branching pattern (very few secondary branches) in D. gracilis is markedly different from that of D. albus (5-7 pairs of cerata with considerable secondary and tertiary branch- ing). Also the coloration of D. gracilis is distinctly differ- ent from that of any other species of Dendronotus. Neither the reproductive system nor any aspects of ecolo- gy are mentioned by Basa (1949). Body Dimensions, Texture, and Apertures The largest specimen of this limaciform, relatively “deli- cate” species was 2.5cm L (Basa, 1949). Miller (pers. comm.) reports that his largest specimen is 0.6cm L. Width and height are not given in either case. The anus is on the right side between cerata no. 1 and no. 2. Below and just anterior to the first right ceras lies the genital aperture. The cardiac prominence is not men- tioned. According to Basa (1949), the body is smooth, but Miller (pers. comm.) says the body is covered with small conical tubercles. Foot There is no mention of the foot by Bapa (1949). The figure (Basa, op. cit., plt. 35) shows the dorsal aspect of the animal so no information regarding the foot can be ob- tained from it. Color The body color is bluish-white and the cerata, crown and veil papillae are opaque white. The clavus of the rhino- Page 462 phore is dark yellow (Basa, 1949) or opaque white (Mil- ler, pers. comm.). This color pattern is somewhat akin to that of Dendronotus albus, but the rest of the “coloration of [D. gracilis] is unmistakable” (Basa, op. cit., p. 167). About 15 “yellow ocelli, each with an orange spot in the centre, are irregularly scattered on the back [dorsum]” (Basa, loc. cit.). The color plate also shows what may be 4 patches of white pigment in a mid-dorsal medial line ex- tending from the posterior pair of cerata to the tip of the tail (these may also be the 2 “accessory cerata” mentioned below; see Cerata). Miller (pers. comm.) noted 5 longi- tudinal rows of yellow spots: 1 mid-dorsal, 2 dorso-lateral, and 2 lateral. Cerata Basa (1949) mentioned 4 pairs of short cerata while Miller (pers. comm.) found 5 pairs on the 0.6 cm animal. These divide into 2 or 3 main branches in what appears to be a “rosette” pattern (Figure 4b). There are fewer secondary branches than in any other species of Dendro- notus and tertiary branches appear to be lacking com- pletely. Posterior to the last pair of cerata are 2 “accessory cerata,” the size and branching pattern of which is not described. Rhinophore and Clavus There is neither a lateral papilla nor a posterior crest (such as Dendronotus iris has) on the round rhinophore stalk. The clavus is perfoliate with 8-17 leaves (Baza, 1949, text fig. 109b; Miller, pers. comm.). There are 4-6 simple or branched, approximately equal, but short crown papillae around the relatively large clavus. Head, Lips, and Veil Basa (1949, p. 167) described 4 relatively simple, ap- proximately equal veil papillae. However, the diagram (text figure 109a) shows a third pair of short, simple papillae between the medial (no. 1) and lateral (no. 3?) veil papillae. No lip papillae are mentioned or dia- grammed. Jaws The jaw is about 2.5 mm L or about a tenth the length of the animal. The long axis of the dorsal process is at nearly right angles to the long axis of the body of the jaw (Basa, 1949, text fig. 109d). This is a greater angle than seen in any of the other species of Dendronotus and may be one THE VELIGER Vol. 12; No. 4 of the more useful taxonomic characters of this species. The masticatory process of the jaw sports about 40 hook-shaped denticles along the masticatory border. Radula The radula formula is 41 (8-1-8) in the one specimen Basa (1949) examined. On each side of the median tooth cusp there are 17 - 20 relatively small denticles decreasing in size towards the apex. The cusp is quite low, being about 23 as wide as high (Basa, op. cit., fig. 109f). Of the 8 lateral teeth, the medial 6 have cusps and denticles while the outer 2 have neither. The cusp of the no. | lateral tooth is about equal in size to the 4 denticles of that tooth. In teeth nos. 2 - 4 the cusp increases in size and then decreases in nos. 5 - 6. On teeth nos. 2 - 6, there are 7 - 9 denticles which are largest on no. 2 and decrease progressively to become mere serrulations on no. 6. Reproductive System No mention is made of the reproductive organs by BABA (1949). A detailed description of the system would be useful in more securely identifying the status of this species within the genus. Geographical Distribution Basa’s one specimen was collected in August, 1939, from 160m at Amadaiba, Sagami Bay, Japan. Miller (pers. comm.), dredging from 9 - 24 m in New Zealand waters, collected 2 specimens on hydroids growing on Glycimeris valves. Dendronotus subramosus MacFarLanp, 1966 (Plate 64, Figure 33; Text figures 3, 4, 6, 19 - 21) Dendronotus subramosus MacFartanp, 1966, Mem. Calif. Acad. Sci. 6: 265 - 270; plt. 40, fig. 3; plt. 46, figs. 5 - 8; plt. 47, figs. 3-7; plt. 49, figs. 1-3; plt. 50, fig. 2 plt. 52, figs. 1-2 Taxonomic Remarks Except for the original description, no information con- cerning Dendronotus subramosus has been published. Marcus (1961, p. 34) includes, under D. frondosus, animals which “... are translucent grey with two brown stripes on either side between the insertions of the cer- ata ....” but these are probably D. swbramosus. Ecolog- Vol. 12; No. 4 THE VELIGER Page 463 ical as well as morphological data lead me to consider D. subramosus a valid species, distinct from D. frondosus. Body Dimensions, Texture, and Apertures The limaciform, moderately “heavy” body, is laterally compressed. The rounded dorsum merges into the vertical sides with no distinct dorso-lateral boundary save the cerata (Figure 3). The largest animal that I have found was 6.5cem L & 18cm H X 0.9cm W while that of MacFartanp (1966) was 4.0cm L & 0.8cm H X 0.55 cm W. 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