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NOLLNLI: ee < Sa oe eS = Cat wo = \’. & ox = One sal [og = fac’ = NG ON = <% aa < = < pale SAN oc = oc S oc = ec Ss oh = i = = 5 = = = e) — oO = 2) _ ie) Bee ee ae ai =z 4 Zz = Zz THSONIAN INSTITUTION NOILOLILSNI SdluvVeai1_ LIBRARIES INSTITUTION NOILALI in = Or B Tee 3 i= Zz. ya S a = = S 0 S Giiy, > : 2 E 2 E = 5 bjp jf > = cs E > = pres S&S $C: zi = ts = 3) = a = wn = n _ ep) = wn = NOSHLINS S3tuvugiT_ LIBRARIES SMITHSONIAN INSTITUTION NOILOLILSNI_NVINOSHLIWS SaluvugiT_LIBRAR = Ws, ‘ = a z ry < = / =a = Ys. =. z oS Vit Jy, = = z SS 5 GE z 8 i Jf? : 3 N oO i, SOE O t ffi, oe : 220 7" 2 = $9 fer = g = \ . > — = Ver | xa . 2 2 Ee ae 5 : ane: THSONIAN INSTITUTION NOILOLILSNI_ NVINOSHLIWS SAINVYGIT LIBRARIES SMITHSONIAN INSTITUTION NOILNL LIBRARIES SMITHSONIAN WSK Ss SS NS NOILALILSNI LIBRARIES NONLALILSNI LIBRARIES NOILALILSNI LIBRARIES NOILNLILSNI NOSHLINS SAINYVHYASIT LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S3IMVYSIT LIBRAR ie z ss = e z Es z S een 2) = 2 o 2 w SEE z E 2 E 2 S 2 VEE 2 ze F a F : SQ ze Ci =e fad = a = ae ~ 7) = a) = a) 4 ” ITHSONIAN INSTITUTION Pe Lady boinc Lich ce 1uYvud ao) BRARI ES SMITHSONIAN INSTITUTION | NOILN LI Ze z z = S& = < « S EMS 2 Wor? 2 Wf ty & AN 3 é 2 a Wis . 8 yf f 77) B hy A N& Te 7) Ee My Z, ENY 24 ? Sag ENN 3 : ay = > Ufo = > = es > > OO ” 5 Fa wn Fa 73) sy — ” : Fe INOSHLINS SJIYVYYSIT LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI NVINOSHLINS S3I1YVYSIT_ LIBRA ” = wo = (Jp) = Yn a WwW < WwW z uJ z WY. Ww 2 Se z : 2 : GAO z tS. " : = Zz (22) %Y 7 NVINOSHLINS S3IY¥VYSIT NVINOSHLIWS NN \ NS SMITHSONIAN SMITHSONIAN Y 4 Yi, F NVINOSHLIWS ITHSONIAN INSTITUTION NO!ILOLILSNI NVINOSHLINS S3ZIYVYUGIT_ LIBRARIES SMITHSONIAN INSTITUTION NOILOLIL NOILNLILSNI NOILNLILSNI LIBRARIES NOILNLILSNI ee tLiNS S3tYvVYEIT LIBRARIES SMITHSONIAN INSTITUTION NOILNLILSNI SASIYVYUS!I7 LIBRARI S3INVNGIT LIBRARIES INSTITUTION NOILNLILSNI S3INVNGIT LIBRARIES INSTITUTION INSTITUTION INSTITUTION SAJ1Y¥vVydlI INSTITUTION NOILNLILSNI_ NVINOSHLINS S31uvVUYGIT_LIBRARIES INSTITUTION NOILALIL WS SAINVYSIT_LIBRARIES SMITHSONIAN z : 2 z = Bes z ” Ex VERMEI] 0. ota ee ene 264 ROBERTONJARAMILLON 24 a ner eee 297 ll Induced spawning and ontogeny of Modiolus capax Conrad (Bi- valvia: Mytilidae). JAVIER ORDUNA ROJAS AND BLANCA CLAUDIA FARFAN .. 302 A new species of Mopalia (Polyplacophora: Mopaliidae) from the northeast Pacific. ROGER N. CLARK Number 4 (October 1, 1991) A bibliography and brief biography of G. Alan Solem, 1931- 1990. ELIZABETH-LOUISE GIRARDI 317 Growth, size at sexual maturity, and egg-per-recruit analysis of the abalone Haluotis fulgens in Baja California. S. A. SHEPHERD, S. A. GUZMAN DEL PROO, J. TURRUBIATES, J. BELMAR, JANINE L. BAKER, AND P. R. SLUCZANOWSKI 324 Growth rings within the statolith microstructure of the giant squid Architeuthis. GEorRGE D. Jackson, C. C. Lu, AND MALCOLM DUNNING . . = 0:6 6 p's GIE-ONE G/ONa! Br aTh ee Tete Carnet ee nee ee cee 331 Seasonal variation in biochemical composition of three size classes of the Chilean scallop Argopecten purpuratus Lamarck, 1819. GLORIA MARTINEZ ili The family Galeommatidae (Bivalvia: Leptonacea) in the eastern Atlantic. ISERGE|G ORAS I= aay sstoris sutects aeCaies lease nua ee ee 344 A new middle Eocene potamidid gastropod from brackish-marine deposits, southern California. RICHARD RE SOQUIRES A ia nari an ences ce ee 354 The Philadelphia syntypes of Ammonites hoffmanni Gabb (Cre- taceous) (Mollusca: Ammonoidea). PETER U. RODDA AND MICHAEL A. MURPHY ........ 360 Corbula kelsey: unmasked: a Cumingia (Bivalvia). EUGENE V. COAN AND PAUL SCOTT................ 366 Pycnogonid predation on nudibranchs and ceratal autotomy. WILLIAM H. PIEL 366 AUTHOR INDEX ANVETAR | We ghts RS ane es ern er nay ae 21, 229 BAKERS Ups Dies clase euie wtn ants us craaneedeesh seep yitle nen eet eae 324 BASHORE. #aLa his oie Berens Sete ee I Gee eee 214 BELMAR Js cachet choy seo Ww Peer ae sb Soecean cena eae 324 BIBEER: sRoi 3 5 psec cai ke NA acne aE ers Re (316) BONG MER. Ds es See eee Ee a emer 229 IBUCKEAND-NICKSSJicg gins cee ee ee ee ae 204 BULLOCK RIG IS fee eta ries Se eee 14, (369) GANTERAGCK® JdRei gta tap seria s a tke eee eee 78, 85 GASTROM Ki Mb soe ee ree 14 GERVERA; = Ji Hiss ia oe sees, RN eee dee ecard eee 56 GOBTAR ESS iy ss yes Ged actns i Nr es Bae 204 GLARKs RNi psec ess ere Oe 91, 309 GOANG EVE OUR EAS 5 Sore rare ete beh oie nn 366 GOLUSSOS AG Us cusex sac ana ee ere ene og a ete 229 GOSTA: FACIES eae tig mice te aise e aa IGES eer pat Bt ree We eye ane 229 COUNTS; (CSP ae rs eee eae ay ce eee ae 214 DAL IBOs Ga MERED oo cack ace ate oe oe ne 229 IDEAL TERIS Ni ey el se ceed ike sheets tie sen een ae 14 TE WINNING ol Mit og oh sfrecitre k ers 331 IEARPANS IB is Gree repeats as peer eer ca eee we em eee 302 ERT Z Vee eect catad pc Bias Aine ee ee er a |e Ee eer 222 GARCIA-GOMEZS Au Gy oe erty eee rae 56 GIRARDI: Ese eg att eee ee ce ee 317 GOBAS 4S Bic tes, foes eee aig Sate ee Tg eae ees 344 GOSTINERS0e9) V0 is Pp eck at Hees enone mt ae ee ip O22 GUZMAN; DELERROOMS ACE a eee Le ee 324 ET AVINES 2A 50. p- co) cues Scheer hee nt end ed anise ya an pre 166 LRAT Y: V2. at ck cage ne co cote see ee ree eran gee rane 134 FAIRANOS YY Sa) ih 3s arse rere ee ee ae eR a eee 48 JACKSON) GoD TS eceni onan See hae eee ee 331 SPAR ANIETO SRE foe) in. aise aah ERE pase ts age ep ane 297 IKKEN CHING TONFSVV in terse eee Le 166 KUZIRTAN SACU Min Lo nee ena ee rt oy ear eras gear ee 48, 195 IGONGEEY. RSD) o Pe cana pene eed ee wee are 291 M@PEZ-GONZALEZ, (Pa i)n cies acaema tad negra eee eee ye 56 ] (OF On Cree eae cneriee nee te ne eenv im enn BEETS ArS SoS oo 5 6 331 TEWRZ RASS, Seis ose copdnansate ulate a ae 222 MIARSHAL IS :AL DS 6 ough an bn nee 91 MARSHAL Is Jit Gucte vine sae cos a hee 91 MPARTINEZ 5! Gir yea esas ae see ie ee 335 MCLEAN; Jin deo oo ec oad eee 38 MEAD Jie: Togscccscoceestace diyaisiain Cele Riou eee 259 MURPHY, MivAm lc 5. Soe ee eee 360 INAKAYAMA Teich oe es 88 OKUTANI, Ws ceo. Sec eee i, 72 ORDUNAJROJASS ino 5 a oe ca oe ee 302 BHILLIPS DSW ce rine ae eae (370, 371, 372) PIED; We. He 52 ee eee 366 POINAR, GwOsJRe ait 3s fas eee oe 253 PROO;)S. Ai D: Be ss. he han wed eee 324 RAGONE LMe 22502 eed ee eee 222 ROBERTSON; (Roc 33 2 occas oe eee (315) RoppaA:.P U2 gee Pa ee bl eee 360 ROJAS;, J -Oe sions ans Hs letoae We be naee eee 302 ROMEY,“ Ws Tih 3.5293 oo eee 14 ROTH? Bei sesek eo is ee (232), 253 SAITO (Fie ses 26s hoc ioe Goencisuicoll ote ee ee G2 SANTOS; S.C oc sus thas ao eee 21 SCHELTEMA\ AGE. 2. a ies eee eee 195, 204 SCOTT; Peck oo esd eos Swe eee 366 SHEPHERD) Sy Avi). oa Sais OR eee 324 SILVA: COSTA, AD! ooh in Sa ee eee 229 SLUGZANOWSKI, (Pl iRe 3. 0) ee eee 324 SOLEM;. Au) occ ck elas ck oe Sache 233 SQUIRES SRe lining 5 toa en AO ee 67, 73, 354 TSUBOKAWA,, Revs soso sec ee eh eee 1 TURRUBIATES, J). 6. hats cee. oe ce oe 324 VAN DEVENDER, TE. Ro). 5 ee eee 259 VERMEIJ,'G. Jin hc. sok wea hao ae ee eee 264 WHORFF,, Jos cc dicue once ashi be ee eee 32 WiIEEANS Re © otad co eee ne eee 97, 134, (368) Page numbers for book reviews are indicated by parentheses. iv ELE VELIGER A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, INC. Berkeley, California R. Stohler, Founding Editor Volume 34 QL 4o| VX Moll, January 2, 1991 CONTENTS Early life history of Plewrobranchaea japonica Thiele, 1925 (Opisthobranchia: Notaspidea). RSVOKOMESUBOKAWAVAND (PAKASHIIOKUTANI «52. 242-25 e sete tae 1 Recruitment in the deep-sea wood-boring bivalve Xylophaga atlantica Richards. WILLIAM L. ROMEY, KATHLEEN M. CASTRO, JOSEPH T. DEALTERIS, AND INOBERGa Cams WIE OC Kae crept ron bible ra bcd, Siang 2 er NLS all) co, 14 Functional anatomy of Castalia undosa undosa (Martens, 1827) (Bivalvia: Hy- rildae). WWAGNERGE Ee AVELAR AND) SANDRA CID SANTOS ...,....0...0.0 8.3. 21 Commensals associated with Xenophora (Onustus) longley: Bartsch (Mollusca: Gastropoda) in the Gulf of Mexico and Caribbean Sea. JIGIBIING, WTSI OTRU RE Ld sory eR eet eg Dette ee nes ea B2 Four new pseudococculinid limpets collected by the deep-submersible Alvin in the eastern Pacific. RAIVIE Sleep VLGIIRAN a atet tinea Sorin nite ate oN ce Abia Bivins at mea c ta 38 A new species of Flabellina (Nudibranchia: Aeolidacea) from Oshoro Bay, Japan. WOSHIAKIO | alIRANOVAND ALAN Mia KUZIRIAN) 22222592) 22583535. 48 Taxonomic and geographical range data on two rare species of Okenia (Gas- tropoda: Nudibranchia: Doridacea) from the eastern Atlantic. J. L. CERVERA, P. J. LOPEZ-GONZALEZ, AND J. C. GARCIA-GOMEZ ...... 56 CONTENTS — Continued The Veliger (ISSN 0042-3211) is published quarterly on the first day of January, April, July, and October. Rates for Volume 34 are $28.00 for affiliate members (including domestic mailing charges) and $58.00 for libraries and nonmembers (7n- cluding domestic mailing charges). For subscriptions sent to Canada and Mexico, add US $4.00; for subscriptions sent to addresses outside of North America, add US $8.00, which includes air-expedited delivery. Further membership and subscription infor- mation appears on the inside cover. ‘The Veliger is published by the California Ma- lacozoological Society, Inc., % Museum of Paleontology, University of California, Berkeley, CA 94720. Second Class postage paid at Berkeley, CA and additional mailing offices. POSTMASTER: Send address changes to The Veliger, Museum of Paleon- tology, University of California, Berkeley, CA 94720. ISSN 0042-3211 Number 1 THE VELIGER Scope of the journal The Veliger is open to original papers pertaining to any problem concerned with mol- lusks. This is meant to make facilities available for publication of original articles from a wide field of endeavor. Papers dealing with anatomical, cytological, distributional, eco- logical, histological, morphological, physiological, taxonomic, evolutionary, etc., aspects of marine, freshwater, or terrestrial mollusks from any region will be considered. Short articles containing descriptions of new species or lesser 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 specimen must be included in the manuscript. ‘Type localities must be defined as accurately as possible, with geographical longitudes and latitudes added. Very short papers, generally not exceeding 500 words, will be published in a column entitled “NOTES, INFORMATION & NEWS”; in this column will also appear notices of meetings, as well as news items that are deemed of interest to our subscribers in general. Editor-in-Chief David W. Phillips, 2410 Oakenshield Road, Davis, CA 95616, USA Editorial Board Hans Bertsch, National University, Inglewood, California James T. Carlton, University of Oregon Eugene V. Coan, Research Associate, California Academy of Sciences, San Francisco J. Wyatt Durham, University of California, Berkeley William K. Emerson, American Museum of Natural History, New York Terrence M. Gosliner, California Academy of Sciences, San Francisco Cadet Hand, University of California, Berkeley Carole S. Hickman, University of California, Berkeley David R. Lindberg, University of California, Berkeley James H. McLean, Los Angeles County Museum of Natural History Frank A. Pitelka, University of California, Berkeley Peter U. Rodda, California Academy of Sciences, San Francisco Clyde F. E. Roper, National Museum of Natural History, Washington Barry Roth, Santa Barbara Museum of Natural History Judith Terry Smith, Stanford University Ralph I. Smith, University of California, Berkeley Wayne P. Sousa, University of California, Berkeley Membership and Subscription Affiliate membership in the California Malacozoological Society is open to persons (no institutional memberships) interested in any aspect of malacology. As an afhliate member, a person may subscribe to The Veliger for US $28.00 (Volume 34), which now includes mailing charges to domestic addresses. ‘There is a one-time membership fee of US $2.00, after payment of which, membership is maintained in good standing by the timely renewal of the subscription; a reinstatement fee of US $3.00 will be required if membership renewals do not reach the Society on or before October 1 preceding the start of the new Volume. If a receipt is required, a self-addressed, stamped envelope (or in the case of foreign members, the envelope and two International Postal Reply coupons) should be included with the membership or subscription request. The annual subscription rate to The Veliger for libraries and nonmembers is US $58.00 (Volume 34), which now includes mailing charges to domestic addresses. For subscriptions sent to Canada and Mexico, add US $4.00; for subscriptions sent to addresses outside of North America, add US $8.00, which includes air-expedited delivery. Memberships and subscriptions are by Volume only (January 1 to October 1) and are payable in advance to California Malacozoological Society, Inc. Single copies of an issue are US $25.00 plus postage. Send all business correspondence, including subscription orders, membership applications, payments for them, changes of address, to: The Veliger, Museum of Paleontology, 3 Earth Sciences Bldg., University of California, Berkeley, CA 94720, USA. Send manuscripts, proofs, books for review, and correspondence regarding editorial matters to: Dr. David W. Phillips, Editor, 2410 Oakenshield Road, Davis, CA 95616, USA. THIS PUBLICATION IS PRINTED ON ACID-FREE PAPER. The Veliger 34(1):1-13 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 Early Life History of Pleurobranchaea japonica Thiele, 1925 (Opisthobranchia: Notaspidea)! RYOKO TSUBOKAWA? and TAKASHI OKUTANI Tokyo University of Fisheries, 4-5-7 Konan, Minato-ku, Tokyo, 108 Japan Abstract. The early life history of the notaspidean opisthobranch Pleurobranchaea japonica Thiele, 1925, was observed by light microscopy to elucidate the normal morphological changes in development from the egg to the crawling juvenile stage. This study confirmed that P. japonica has typical plank- totrophic development (Thompson’s development-type 1), and that the mantle originates from the mantle fold of the veliger larva. The larval shell is not cast off but is lost by dissolution or absorption. The origin and subsequent development of the mantle is the same as with another notaspidean, Berthellina citrina (Ruppell et Leuckart), though the developmental type of the latter species is lecithotrophic. INTRODUCTION Pleurobranchaea japonica Thiele, 1925, is the commonest notaspidean opisthobranch along the coasts of Honsha, Shikoku, and KyUtshu in Japan. Pleurobranchaea japonica lives on either muddy and sandy substrates in shallow water or on intertidal rocky shores. Many individuals are caught as a by-catch of commercial bottom trawling on muddy bottoms such as in Tokyo Bay, Middle Honsha. From February to June on the Pacific coast of middle Honshu, egg masses of this species are found on rocky substrates and seaweed in the intertidal zone or on shallow bottoms. As is the case with other members of the order Notaspidea, little is known about the life history of this species. The aim of the present study is to elucidate the normal embryological and post-embryological changes from the egg up to the juvenile stage, using light-microscopic observations on live animals reared in the laboratory. The only notaspidean whose development has been studied from the uncleavaged egg to the juvenile is Berthellina citrina (Ruppell & Leuckart) (GOHAR & ABUL-ELA, 1957; UsUKI, 1969). MATERIALS anp METHODS Most of the adult animals used for the present study were collected by a commercial trawler operating in the waters off Yokohama, Tokyo Bay, at depths of 20 to 40 m, during ' Contribution No. 508 of the Shimoda Marine Research Cen- ter, University of Tsukuba. 2 née Inoue. the period from February to July 1987. Animals were also collected from the rocky shore of Nabeta Bay, Shimoda, in Izu Peninsula, Middle Honsht. Adults were paired and reared in laboratory aquaria with running seawater. Thirty-two egg masses that were laid by adults in cap- tivity were kept in aquaria either with unstirred seawater that was changed daily, or they were placed under a tap of dripping seawater. Water temperature was not regu- lated, and ranged from 13.5 + 0.70°C to 22.6 + 0.45°C. Just before hatching, all egg masses were placed in stand- ing seawater overnight. Newly hatched larvae were pipetted into beakers con- taining 2500 mL of seawater, which had been filtered through absorbent cotton. Cultures were stirred by a pro- peller at 60 rpm (Figure 1). Initial densities in each beaker were in the range of 125 to 750 larvae. They were fed daily on cultures of Chaetoceros gracilis Schutt, Tetraselmis chur Butcher, and Nannochloropsis oculata (Droop) Hib- berd. The water temperature ranged from 22.2 + 0.85°C to 24.7 + 0.55°C. Juveniles that settled on the bottom of the rearing beak- ers were transferred into styrene plastic cylinders capped with netting that allowed overflow of excess seawater, which had been supplied through a tube. The range of temper- atures during the rearing of juveniles was from 15.2 + 0.70°C to 23.2 + 1.85°C. Juveniles were fed dried bonito powder or crushed cephalaspid (Haloa japonica (Pilsbry)). They were also given microbiota grown on a polyvinyl plate that had been immersed in running seawater in an outdoor pool and washed with freshwater immediately Page 2 Figure 1 A water circulating system with three 3000-mL beakers for rear- ing larvae of Pleurobranchaea japonica. before being placed in the rearing cylinders. The devel- opment from egg to juvenile was observed under a light microscope using both anesthetized and non-anesthetized embryos, larvae and, juveniles. Anesthetization was made by the method of BICKELL & KEMPF (1983). RESULTS Oviposition Paired adults repeated copulation and oviposition in the laboratory aquaria until death, with copulation and ovi- Figure 2 Dorsal view of copulating animals, Pleurobranchaea japonica. Ar- cates extended penis of the animal on the left. The Veliger, Vol. 34, No. 1 Figure 3 An animal in oviposition. A. Dorsal view with egg mass (arrow). B. Right lateral view of the same. position usually occurring at night. Animals explore pro- spective mates with the papillose margin of the oral veil. Prior to copulation, two individuals orient in opposite di- rections with their right sides opposed. Each animal raises its right mantle edge, exposing its genitalia, and then ex- tends the penis, which can swell to % of the body length (Figure 2). The tip of the penis is used to feel for the vagina of the partner, which opens on the body wall at the base of the male genital organ. Usually, both individuals lay egg masses on the same day or within two or three days after copulation (Figure 3). Oviposition tends to occur every four to six days in aquarium-held pairs. ‘The maximum number of egg mass- es recorded for a single pair in captivity was 16, laid in 43 days, before the adults died. Morphology of the Egg Mass An egg mass consists of a cylindrical, gelatinous string, 8 to 10 mm in diameter and 19 to 64 cm (36.9 cm mean for 60 egg masses) in total length (Figure 4A). On average, each centimeter of gelatinous string contains 30 coils of spiral, membranous tube, holding 64 primary egg capsules per coil. Each primary egg capsule contains 1-12 (7.5 mean for 48 capsules from 12 egg masses) opaque primary oocytes (Figure 4B). Thus, a whole egg mass is calculated to contain about 530,000 primary oocytes. A thin gelati- nous sheet, 2 to 3 mm in width, attaches the egg mass to the substrate in the form of a single or double anti-clock- R. Tsubokawa & T. Okutani, 1991 Figure 4 A. An egg mass on algae. Osezaki, Izu Peninsula, Middle Japan, 25 April 1989, water depth 6 m. B. Egg mass, magnified. Primary oocytes in the primary egg capsules are contained in a membra- nous tube. Key to the abbreviations used in Figures 4 to 14: a, anus; ah, adult heart; bm, buccal mass; e, eye; ec, primary egg capsule; ep, oesophagus; f, foot; g, gill; gc, green-colored cell; hb, hyaline rodlike bodies; i, intestine; j, jaw; Id, left digestive diver- ticulum; lh, larval heart; lm, larval mouth; m, muscle; mb, mem- branous tube; mc, mantle cavity; mf, mantle fold; mt, mantle; 0, primary oocyte; ov, oral veil; p, propodium; pc, pigmented cell; po, postoral ciliary band; pr, preoral ciliary band; r, radula; rb, reddish body; rd, right digestive diverticulum; rh, rhinophore; rm, retractor muscle; s, shell; sc, statocyst; st, stomach; tb, trans- parent body; v, velum. wise whorl 5 to 10 cm in diameter, sometimes with a trailing end. Early Embryogenesis Within an hour after oviposition, the fertilized primary oocyte releases two polar bodies, and the primary polar body divides into two. The ovum, measuring 100 um in diameter, undergoes spiral cleavage. A development schedule from oviposition to hatching is represented in Table 1. A ciliary band ap- pears anterior to the blastopore. These cilia later lengthen and become the prototroch of the trochophore. Beating of Page 3 Table 1 Days from oviposition required for completion of each developmental stage at different water temperatures. Water temperature Stage Days (°C) Blastula 1 18.0 + 3.50 2 14.4 + 1.55 Gastrula 2 18.0 + 3.50 3 14.1 + 1.00 Trochophore 4 14.8 + 0.30 5 14.5 + 1.45 6 13.7 + 0.55 Hatching 6 21.0 + 1.20 if 15.4 + 0.85 8 14.0 + 1.15 the prototroch cilia causes the trochophore to move actively in the egg capsule. Larval Structure at Hatching The newly hatched larva (Figure 5), has a sinistral shell that corresponds with THOMPSON’s (1961) shell-type 1. The larval shell first appears at the posterior end of the trochophore, and it expands to cover all but the foot and velar rudiment as a single coiled larval shell of the veliger (Figure 6A). The larval shell is smooth, transparent, and colorless. On the inner lip region there are four to six ridges about 10 wm apart (Figure 6A-C). The outer lip is plain. The shell measures 152 um to 183 um (mean, 162.6 um; SD, 10.80; n = 23) in width at the time of hatching. This species possesses no operculum at any time during the entire developmental process. In the trochophore stage, the region bearing the ciliary band protrudes to form an inverted heart-shaped velar rudiment in anterior view. The velar rudiment grows to be a velum typical of planktonic veliger larvae (Figure 5B, D, v). The foot rudiment appears as a blunt process, which lengthens to be the slender, club-shaped larval foot about 80 wm in length. The ventral side of the foot bears short, crowded cilia and a blunt.tip, which projects out from the shell aperture and has a tuft of long cilia measuring about 30 wm in length (Figure 5B, D, f). In the newly hatched larva a fleshy ridge of the mantle fold extends along the inside of the aperture of the shell a little behind the shell margin (Figure 5B, D, mf). The ridge can be freely withdrawn and extended. The mantle cavity is limited to a narrow space between the mantle fold and the head (Figure 5B, mc). The visceral region of the trochophore consists of three lobes of undifferentiated cells. These lobes differentiate to form the stomach and two digestive diverticula of the ve- liger (Figure 5B, D, st, Id, rd). A newly hatched larva has Page 4 The Veliger, Vol. 34, No. 1 f Id I Figure 5 A. Right lateral view of veliger larva in egg capsule. Scale bar = 100 um. B. Diagrammatic representation of right lateral view of veliger larva. C. Left lateral view of veliger larva in egg capsule. Scale bar = 100 um. D. Diagrammatic representation of left lateral view of veliger larva. The two axes indicate the anterior-posterior axis (x-x’) and ventral-dorsal axis (y-y’) of the larval body, respectively. See Figure 4 for key to abbreviations. a larval mouth between the preoral and postoral ciliary bands at the ventral base of the velar lobes. The larval mouth is surrounded by short, constantly beating cilia. A large left and the small right digestive diverticula occupy the ventral half of the visceral mass, and the difference in size between the two varies among individuals at hatching. An ellipsoidal stomach lies between the digestive divertic- ula and is connected with the oesophagus ventrally. Hy- aline, rodlike bodies (THOMPSON, 1959) are distributed densely in the right posterior region of the stomach wall (Figure 5B, hb, and Figure 11). The stomach narrows dorsally into the intestine, which continues to the anal opening on the right side of the body in the mantle cavity (Figure 5B, i, a). A globose structure appears on the right side of the body immediately after the formation of the prototroch, and gradually becomes distinct as it acquires a reddish color (Figure 5B, rb). Subsequently, a transparent structure, which is similar in shape and size to the red one, appears beside and just above it (Figure 5B, tb). A newly hatched veliger has velar and pedal retractor muscles (Figure 5D, rm). The bundles of retractor-muscle fibers originate at their attachment on the shell at the posterodorsal region just to the left of the midline, and extend past the left side of the stomach to insert into the head and base of the foot. Several small visceral muscles connect the visceral mass with the perivisceral epithelium (Figure 5D, m). A pair of statocysts appears at the base of the foot ru- diment on the ventral side of the body early in the mor- phogenesis from trochophore to veliger stages (Figure 5B, D, sc). Each statocyst contains a statolith, which constantly vibrates. Newly hatched veliger larvae lack eyes. The behavior of newly hatched larvae was similar to that typical of planktotrophic opisthobranch veligers (HADFIELD & SWITZER-DUNLAP, 1984). R. Tsubokawa & T. Okutani, 1991 Morphogenesis from Newly Hatched Larva to Competent Larva After hatching, larvae feed on phytoplankton and in- crease in size and morphological complexity as they ap- proach the juvenile stage. Differences in initial larval den- sity and rearing temperature affected survival rates and planktonic duration. The minimal period from hatching to metamophosis was 15 days at an initial larval density of 250 individuals per 2500 mL (22.8 + 1.7°C) and 17 days at 500 or 750 individuals per 2500 mL (both 23.7 + 0.85°C). Shell width gradually increases up to 445.8 um (mean; n = 24; SD, 40.14) just before metamorphosis (Figure 8). The general features of the shell exhibit no marked change from the time of hatching. The velum becomes larger and more flexible as the larva grows. Each lobe can be extended up to 1 mm and cannot be withdrawn entirely into the shell cavity when the animal retracts. Several large green cells aFe scattered on the velar lobes (Figure 14B, gc). Larvae of Pleurobranchaea japonica feed in a manner typical of that for planktotrophic opis- thobranch larva (THOMPSON, 1959). The sole bears short cilia. The anterior edge of the foot widens and elevates to form a propodium (Figure 7D, p). The foot of a competent larva measures up to 300 wm in length, and has a thick propodium. By 4 to 6 days (22.7 + 1.6°C) after hatching, the mantle fold extends anteriorly and thickens to project beyond the shell aperture. Subsequent growth carries the mantle fold over the shell margin to the outer surface of the shell (Figure 9). As the larva grows, the reflected mantle fold bifurcates, leaving a narrow slit along the mid-dorsal line of the shell. At this time, the mantle fold can be withdrawn towards the shell aperture, but it can never be retracted into the shell cavity. Subsequently, the slit is gradually obliterated, starting from the anterior region of the mantle overgrowth. Just before settlement, the two lobes of the mantle fold completely fuse with each other at their pos- terior end to enclose the entire shell (Figure 7A, B). After fusion the mantle is never withdrawn to expose the shell. After 9 to 11 days (23.1 + 1.95°C) from hatching, the dark brown pigmented cells, which are scattered among the mantle columnar epithelium, increase in number (Fig- ure 9A, pc). The mantle cavity enlarges in the right la- teroventral side of the body (Figure 7C, D, mc). A ciliated region appears in the middle of the mantle cavity just before settlement. The floor of the mantle cavity has a densely ciliated edge that slants to the right and is visible from the shell aperture. A pair of jaws appears at the anterior extremity of the floor of the oesophagus. The appearance of the jaw is followed by the radula, which carries at least 12 lateral teeth in each of two rows (Figure 10). According to the present observations with a light microscope, the buccal mass including radula complex becomes evident in the larval buccal cavity just before metamorphosis. It is a cil- Page 5 Figure 6 Larval shell. A. Shell of a newly hatched larva. Scale bar = 100 um. B and C. Ridges on inner lip, magnified. Scale bars = 10 pm. iated bulb with rather long and sparse cilia (Figure 13C, bm). The right digestive diverticulum decreases in size, becoming undetectable in live animals, while the left grows so as to occupy the ventral half of the visceral mass (Figure 7C, ld). Both digestive diverticula become dark brown during pelagic life. The stomach moves dorsally and slants anteriorly, as if displaced by the enlarged left digestive diverticulum (Figure 7C, st). The hyaline, rodlike bodies are as they were in the previous stage (Figure 11). The stomach lumen is divided into two parts with a constriction Page 6 NTANIN Ty 11 Psi SM NOM errata” AM The Veliger, Vol. 34, No. 1 », nu Ww ys W Figure 7 Full grown larva. A. Left lateral view of full grown larva. Scale bar = 500 um. B. Ventral view of full grown larva. Scale bar = 500 wm. C. Diagrammatic representation of right lateral view of full grown larva. D. Diagrammatic representation of frontal view of full grown larva, foot extended. See Figure 4 for key to abbreviations. at the middle. One stylelike food bolus is actively rotated in the stomach by the beating of cilia on the inner surface of the stomach wall. The intestine, which is roughly U-shaped, elongates gradually, and its turning point moves posteriorly (Figure 7C, i). The anus moves somewhat pos- teriorly on the right side of the animal as the mantle cavity continues to enlarge and deepen (Figure 7C, a). The reddish globose structure above the anus gradually blackens and withers into a flat disc, while the transparent structure located next to the red one starts to swell (Figure 7C, rb, tb). These two presumptive excretory organs move somewhat posteriorly along with the anus. The larval heart, a thin, membranous, regularly pulsing tube, develops 5 to 7 days after hatching (23.2 + 1.95°C) (Figure 7C, 1h). It is located somewhat to the left of the animal’s midline between the retractor muscle and the presumed excretory organs. The day after its appearance, the heart increases in size. This species possesses two hearts for a short period during the late larval life. In addition to the larval heart, the competent larva has a globose, transparent, membranous adult heart just above the pre- sumed excretory organs (Figure 7C, ah). The two hearts do not synchronize, but pulse independently. As the mantle fold encloses the shell, the internal organs R. Tsubokawa & T. Okutani, 1991 550 e e e e 450 0 e e e e2 o2 e e 6 e e e e £ 2 04 2 2350 Gea Boia cash c e e2 $ e = e e e2 e3 — e 3 4 e e2 0 = e3 fe e 2 n e2 e2 e e e3 e2 250 ABS e e e e2 02 e4 @ e3 e e3 e3 e2 e4 $ e e3 Y e2 $2 e e 150 13 hatch-out Day Page 7 e e e e2 02 e2 e@ @ ) e e e e e e @2 e e e 15 20 25 30 Figure 8 Growth of larval shell. Data points were obtained from different individuals reared in different beakers. The minimal period from hatching to metamorphosis was 15 days. Numerals attached to the points indicate the number of data points overlapping at that position. become indistinct and the fate of the musculature cannot be traced in living animals. After 5 to 7 days from hatching (23.2 + 1.95°C), the eyes appear as small black spots located on the head just behind the velar base (Figure 7D, e). They become larger and more distinct within two or three days, but as the animal grows they become buried more deeply under the transparent head epithelium. The statocysts remain un- changed since their first appearance. The rudiments of the rhinophores and the oral veil appear before settlement (Figure 7D, rh, ov, and Figure 12). The oral veil first becomes visible at about the middle of the larval period as a small fleshy ridge situated somewhat below the center of the velum. This ridge has a row of short cilia and a pair of depressions at each end. The eyes underlie these depressions. The rhinophores first protrude from the de- pressions a few days after the appearance of the oral veil rudiment. Initially the oral veil grows anteriorly in the center, then along the margin of each side, forming three rises of which the central one thickens markedly. Finally, the oral veil gains volume, becoming trapezoidal in shape and covering the larval mouth. The rhinophores grow toward the center of the velum at first, and after, they change the direction of growth anteriorly and outwardly. In a competent larva, the rudiments of the oral veil and the rhinophores are miniatures of those in the adult. Metamorphosis and Morphology of Juvenile Through settlement and metamorphosis, the mode of larval life changes from pelagic to benthic, and the larva becomes a juvenile (Figure 13A-D). The loss of the velum signals this irreversible change of life. The larval shell, which is entirely enclosed with the mantle fold, is never cast off, but gradually becomes small- er. This probably occurs by dissolution or absorption, and it starts from the inner lip of the shell immediately prior to the loss of the velum. The outline of the shell remnant Page 8 The Veliger, Vol. 34, No. 1 Figure 9 Growth of mantle fold. A. Right posterolateral view of a larva 20 days after hatching. The larval shell is exposed by the slit between the bilobed mantle fold. Scale bar = 200 um. B. Diagrammatic representations of the growth of the mantle fold that finally covers the whole larval shell. Key: pc, pigmented cell; s, shell. a& + 2 eh, ore 5 oe & mag ¥ oF roe __—_——_—_———————————) Figure 10 Figure 11 Hyaline rodlike bodies (arrow) in the right posterior region on Radula and jaw plates of a full grown larva. Scale bar = 50 um. the larval stomach wall. Scale bar = 50 um. Key: j, jaw; r, radula. R. Tsubokawa & T. Okutani, 1991 A Page 9 Figure 12 Growth patterns of rhinophores and oral veil. A and B. Frontal view of a full grown larva. Scale bar = 500 um. C shows the growth series of the framed part in A. Key: ov, oral veil; rh, rhinophore. is visible through the mantle as a reddish line (Figure 13B-D, s). Even after it has lost its velum, a juvenile still carries the remnant of the shell in the left posterodorsal region under the mantle (Figure 13C, D, s). Loss of the shell allows the visceral mass to settle within the foot, and the mantle cavity extends posteriorly along the right lateral side. As the shell remnant becomes reduced to an oval flat plate, the body of the juvenile also becomes flattened like that of the adult. The ciliated cells of the preoral and postoral bands fall off and the other cells of the velum aggregate to create a pair of lobes with many large green cells on each side of the head (Figure 14A, B, arrow head, gc). These lobes gradually flatten and merge into the head epithelium. Some larvae lose one velar lobe a few hours ahead of the other. The time required from the loss of the ciliated cells to the completion of flattening of the lobes is usually half a day. The morphology of the juvenile foot is not significantly different from that of the previous stage except for the loss of the tuft of cilia at the posterior tip of the foot. While the velum is being lost, the larva actively crawls about randomly on its well-developed sole. At the posterior region of the pedal sole of the juvenile there are one or two star- shaped spicules with a minute circle in the center. These spicules are identical to those observed by GOHAR & ABUL-ELA (1957) in Berthellina citrina. As the larval shell disappears, the juvenile extends its head anteriorly, flattening the body. The inner region of the mantle cavity is exposed externally as it moves to the right lateral side of the body. Subsequently, the border of the posterior end of the mantle fold fuses with the upper surface of the foot. The mantle, which is circular in shape at first with a diameter twice the width of the foot, becomes more slender and elliptical in shape. One to three pairs of dark reddish maculations appear near the margins of the mantle (Figure 15). The juvenile begins feeding immediately after the loss of its velum. When feeding, the jaw plates and radula move anteriorly and posteriorly by the action of buccal muscu- lature (Figure 13D, bm, j). The oesophagus elongates to the middle of the body and winds into an S-shape (Figure 13D, ep). The left digestive diverticulum occupies the pos- terior part of the animal (Figure 13C, D, 1d). The intestine could not be identified at this stage in this investigation because it was obscured by the thickened and pigmented mantle. The anus is situated laterally in the right mantle cavity, just posterior to the gill rudiment (Figure 13C, D, a, g). The Veliger, Vol. 34, No. 1 Figure 13 Juvenile of Pleurobranchaea japonica. A. Dorsal view of a juvenile immediately after loss of the velum. Scale bar = 500 um. B. Juvenile one week after loss of the velum, with a remnant of larval shell. Scale bar = 500 um. C. Diagrammatic representation of right lateral view of A. D. Diagrammatic representation of B. See Figure 4 for key to abbreviations. R. Tsubokawa & T. Okutani, 1991 Figure 14 Larvae at settlement. A. Left lateral view of an animal with remnants of a disappearing velum (arrow head). Scale bar = 300 um. B. Ventral view of the head region of an animal losing the velum (arrow head). Scale bar = 200 um. Key: gc, green-colored cell. The flat black disc just above the anus becomes smaller and disappears after settlement (Figure 13C, rb). The transparent globose structure seen earlier could not be observed when the animal had become flattened because of the thick overlying mantle. After settlement the ciliary region in the middle of the mantle cavity develops into a ciliated gill rudiment (Figure 13C, D, gr). The length of the gill rachis and the number of alternating pinnae gradually increase; for example, two days after settlement an individual had only three pinnae on a rachis that was 132 wm long, whereas 15 days after settlement another individual had 10 pinnae on a rachis 305 wm long (Figure 16). The base of the rachis is tubular and located next to the adult heart (Figure 13C, D, g, ah). Just prior to settlement, the adult heart is larger than the larval one. Although the larval heart exists until settlement, it disappears immediately after. The eyes gradually submerge under the head epithelium during the larval stages, although they are still visible for at least two months after settlement (Figure 13C, D, e). The statocysts exist on both sides of the pedal base under the anterior edge of the mantle of a juvenile. The oral veil, which reaches the basic adult shape prior to settlement, enlarges to become functional for feeding (Figure 13C, D, Page 11 Figure 15 Dark reddish maculations on the body of a juvenile. ov). A feeding juvenile senses the prey with the anterior edge of the oral veil, which is papillose and bordered with sparse tufts of short cilia. The dorsal surface of the oral veil, especially laterally, is dark red (Figure 15). The rhi- nophores are similar to those of the previous stage, except that dark red pigmentation appears near the bases (Figure 15). The cilia on the periphery of the rhinophores beat constantly. Just before settlement, a larva creeps over the substrate with its velum extended. One that has lost its velum tends to crawl into a dark crevice. A juvenile will occasionally hang upside down from the water surface using surface tention. The juvenile begins feeding on living or dead an- imal matter using its buccal mass immediately after meta- morphosis. Juveniles are cannibalistic, and individuals dis- playing this tendency grow much larger than others. Newly settled juveniles measure from 800 um to more than 1000 um in body length and from 500 to 900 um in 2 days 15 days 3 pinnae 10 pinnae 132 um 305 um Figure 16 Growth of gill rudiment of a juvenile. The Veliger, Vol. 34, No. 1 Figure 17 Juvenile. Dorsal view of a juvenile 2.5 months after loss of the velum. Scale bar = 5 mm. body width. Juveniles survived at most two and a half months after settlement, and attained 12 mm in body length (Figure 17). The major cause of death was decreased water quality. DISCUSSION The newly hatched veliger larva of Pleurobranchaea ja- ponica belongs to Thompson’s development-type 1 (THompson, 1967, 1976). Although planktotrophic, the larva of this species differs from others in lacking an oper- culum. BONAR (1978) stated that when the nudibranch Phestilla sibogae lost its velum, all the ciliated cells selectively dis- sociated from the supporting tissue of the velum and were ingested as the first postlarval “meal.” In Plewrobranchaea japonica, dissociation of the ciliated cells occurs as in Phes- tilla stbogae, but the ingestion of these cells by the settling animal was never observed. The remnants of the velum are incorporated into the head epithelium instead of form- ing a particular adult organ. BonaR (1978) mentioned two origins for dorsal postlar- val epidermis: one from the mantle fold and the other from the foot. In Pleurobranchaea japonica, the mantle fold is reflected over the apertural margin to enclose the shell completely prior to settlement. Thus, the dorsal postlarval epidermis is formed solely from the tissues of the mantle fold. The development of the mantle and the origin of the dorsal epidermis are the same as those hitherto reported for Berthellina citrina (GOHAR & ABUL-ELA, 1957; UsukKI, 1969). KRIEGSTEIN (1977), SWITZER-DUNLAP & HADFIELD (1977), PERRON & TURNER (1977), and BICKELL & KEMPF (1983) described post-hatching shell growth in the plank- totrophic larvae of aplysiids and nudibranchs. In those opisthobranchs the shell continues to grow until the mantle is retracted from the shell aperture. The post-hatching shell growth in Pleurobranchaea japonica is obvious. In this species, the mantle fold never attaches to the inner wall of the shell, but it can withdraw from the shell aperture. The mantle fold grows to reflect over the shell aperture instead of being retracted within the shell cavity. These features— mantle reflection that results in the complete enclosure of the larval shell, and shell growth that continues after man- tle reflection—may be comparable with post-metamorphic growth of the mantle and shells in the cephalaspids Philine aperta and Philine scabra (HORIKOSHI, 1967). The fate of the larval shell in Pleurobranchaea japonica is hitherto unique among opisthobranchs lacking a shell in the adult stage. THOMPSON (1959) stated that the right mid-gut diver- ticulum functions for yolk storage and plays no part in larval feeding. In Pleurobranchaea japonica, though the right digestive diverticulum decreases in size as the larva grows, its color darkens like that of the left one. This suggests that the right digestive diverticulum, like the left one, may function to a certain extent for larval feeding. In Pleurobranchaea japonica, the oral veil and rhino- phores are almost completely developed at settlement. We consider this to be an example of advanced differentiation of the cephalic structures among examples of opistho- branch development. In the lecithotrophic notaspidean Berthellina citrina, the rhinophoral rudiment differentiates prior to settlement, but completes differentiation much later in the juvenile stage (GOHAR & ABUL-ELA, 1957; UsuKkI, 1969). The formation of the oral veil in P. japonica is different from that in B. citrina; in B. citrina it is formed by the fusion of a pair of tentacles after settlement, whereas in P. japonica the oral veil rudiment is never divided into two tentacles. CHIA & Koss (1982) suggest that rhino- phores, complete with their ganglia, are essential for set- tlement and metamorphosis in the nudibranch Rostanga pulchra, whose metamorphosis is induced by the sponge prey of the adult stage. A prey-specific chemical stimu- lation of settlement and metamorphosis of P. japonica was not detected. Early formation of the rhinophores and the oral veil of P. japonica may enable the juveniles of this species to feed immediately after the loss of the velum. The rhinophores and oral veil of P. californica bear chemore- ceptors that participate in food detection (BICKER et al., 1982). Early formation of the oral veil and the early onset of feeding may be comparable with premetamorphic oral hood differentiation in the nudibranch Melibe leonina (BICKELL & KEMPF, 1983). In agreement with THOMPSON (1958, 1976), no organ was found to exhibit torsion as a mechanical process during the embryogenesis and larval development of Pleurobran- chaea japonica in the present observation. As the shell dissolves in the later larval stages, the mantle cavity deep- ens and changes the direction of the opening, accompanied by the posterior displacement of the anus. This change may be regarded as detorsion in this species, as HYMAN R. Tsubokawa & T. Okutani, 1991 (1967) regarded it on the basis of many works by previous authors. This displacement, however, is not accompanied by a rotation of whole visceral organs, but only by a deep- ening of the mantle cavity, accompanied by elongation of alimentary canal and anal displacement. Pleurobranchaea japonica seems to require no external stimulus for settlement and metamorphosis. This may re- flect the fact that the adults have no specific prey, but eat a broad spectrum of food. This study clarified the general events during the early life history of Pleurobranchaea japonica, which have not hitherto been documented. Such contributions are needed to clarify the infra- and intra-order relationships of the Notaspidea. Such details as cleavage, neural development, and others remain to be studied; these gaps will be filled by future study. ACKNOWLEDGMENTS We are grateful to Prof. K. Kuwasawa of Tokyo Met- ropolitan University and Mr. K. Shishikura and his crew of the trawler for their warm help in collecting most of the materials used in the present study. This study was conducted mainly in the Shimoda Marine Research Cen- ter, University of Tsukuba. We would like to thank Prof. H. Watanabe of the Center for affording all facilities for these experiments, and Dr. Y. Yokohama, Dr. Y. Saito, Mr. H. Ueda, and all other staff of the Center for the valuable advice and cooperation given to us. We are much indebted to Dr. R. C. Willan for valuable suggestions and efforts to correct our English grammar. We also owe many thanks to Mr. K. Konno and Dr. S. Segawa of the Tokyo University of Fisheries for their warm help, understanding, and encouragement during the study. LITERATURE CITED BICKELL, L. R. & S.C. Kempr. 1983. Larval and metamorphic morphogenesis in the nudibranch Melzbe leonina (Mollusca: Opisthobranchia). Biological Bulletin 165:119-138. Bicker, G., W. J. Davis, E. M. Matera, M. P. Kovac & D. J. SToRMoGIPSON. 1982. Chemoreception and mechano- reception in the gastropod mollusc Pleurobranchaea calvfor- nica. 1. Extracellular analysis of afferent pathways. Journal of Comparative Physiology, A 149:221-234. Bonar, D. B. 1978. Morphogenesis at metamorphosis in opis- thobranch molluscs. Pp. 177-196. In: F.-S. Chia & M. E. Rice (eds.), Settlement and Metamorphosis of Marine In- vertebrate Larvae. Elsevier /North-Holland Biomedical Press: New York. Page 13 Cui, F.-S. & R. Koss. 1982. Fine structure of the larval rhinophores of the nudibranch, Rostanga pulchra, with em- phasis on the sensory receptor cells. Cell and Tissue Research 225:235-248. Gouar, H. A. F. & I. A. ABUL-ELA. 1957. The development of Berthellina citrina (Mollusca, Opisthobranchiata). Pub- lication of the Marine Biological Station, Al Ghardaqa, Egypt 9:69-84, 4 pls. HADFIELD, M. G. & M. SwitTzerR-DUNLAP. 1984. Opistho- branchs. Pp. 209-350. Jn: A. S. Tompa et al. (eds.), The Mollusca. Vol. 7. Academic Press: London. HorikosHI, M. 1967. Reproduction, larval features and life history of Philine denticulata (J. Adams) (Mollusca—Tec- tibranchia). Ophelia 4:43-84. Hyman, L. H. 1967. The Invertebrates. Vol. 6. McGraw-Hill: New York. 792 pp. KRIEGSTEIN, A. R. 1977. Stages in the post-hatching devel- opment of Aplysia californica. The Journal of Experimental Zoology 199:275-288. PERRON, F. E. & R. D. TURNER. 1977. Development, meta- morphosis, and natural history of the nudibranch Doridella obscura Verrill (Corambidae: Opisthobranchia). Journal of Experimental Marine Biology and Ecology 27:171-185. SwITzZER-DUNLaP, M. & M.G. HADFIELD. 1977. Observations on development, larval growth and metamorphosis of four species of Aplysiidae (Gastropoda: Opisthobranchia) in lab- oratory culture. Journal of Experimental Marine Biology and Ecology 29:245-261. THIELE, J. 1925. Gastropoda der Deutschen Thiefsee-Expe- dition, Teil II. Wissenschaftliche ergebnisse der Deutschen Thiefsee-Expedition auf dem Dampfer “Valdivia” 1898- 1899 17(2):38-382. TuHompson, T. E. 1958. The natural history, embryology, lar- val biology and post-larval development of Adalaria proxima (Alder and Hancock) (Gastropoda Opisthobranchia). Philo- sophical Transactions of the Royal Society of London, Series B 242:1-58. TuHompson, T. E. 1959. Feeding in nudibranch larvae. Journal of the Marine Biological Association of the United Kingdom 38:239-248. THOMPSON, T. E. 1961. The importance of the larval shell in the classification of the Sacoglossa and Acoela (Gastropoda Opisthobranchia). Proceedings of the Malacological Society of London 34:233-238. TuHompson, T. E. 1967. Direct development in a nudibranch, Cadlina laevis, with a discussion of developmental processes in Opisthobranchia. Journal of the Marine Biological As- sociation of the United Kingdom 47:1-22. TuHompson, T. E. 1976. Biology of opisthobranch molluscs. Vol. 1. Ray Society: London. 207 pp. Usuk1, I. 1969. The reproduction, development and life history of Berthellina citrina (Ruppell et Leuckart) (Gastropoda, Opisthobranchia). Scientific Report of Niigata University, Series D (Biology) 6:107-127. The Veliger 34(1):14-20 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 Recruitment in the Deep-Sea Wood-Boring Bivalve Xylophaga atlantica Richards by WILLIAM L. ROMEY Department of Zoology, University of Rhode Island, Kingston, Rhode Island 02881, USA KATHLEEN M. CASTRO anp JOSEPH T. DEALTERIS Department of Fisheries, Animal and Veterinary Science, University of Rhode Island, Kingston, Rhode Island 02881, USA AND ROBERT C. BULLOCK Department of Zoology, University of Rhode Island, Kingston, Rhode Island 02881, USA Abstract. Recruitment in a deep-sea wood-boring bivalve, Xylophaga atlantica Richards, 1942, was monitored over a two-year period from July 1987 to June 1989 at two locations on the edge of the continental shelf south of Cape Cod in the western North Atlantic Ocean. Average recruitment densities of X. atlantica in test panels varied from 0 to 30 animals/cm*. At the 100-m site, peak settlement was observed between September and December 1987 with a smaller peak from June to September 1988. Recruitment rates at this site declined sharply between January and May in 1988 and 1989. The recruitment rate at the 200-m site remained at relatively high levels during the months of February through April with a significantly higher peak during 1989 as compared to 1988. Low recruitment was observed from May through December in 1987 and 1988. Significant differences in recruitment between the two sites were observed for all sampling periods except for the period April through June, when recruitment was low at both sites. INTRODUCTION Settlement and metamorphosis of most deep-sea sessile marine invertebrates are poorly understood. The pholad subfamily Xylophagainae, whose members have adapted to utilizing wood in the deep sea, has many species dis- tributed throughout the world’s oceans (KNUDSEN, 1961). Although the distribution of individual species in this sub- family is thought to be temperature dependent (PERKINS, 1974), Xylophagainae distribution is also determined by the presence of wood on the sea floor (TURNER, 1973). Wood reaching the deep sea is rapidly decomposed, prin- cipally through the activity of these bivalves, which convert the woody plant material into a food source for detritus feeders, predators, and filter feeders (TURNER, 1977). Xylophagainae presumably utilize wood for both food and shelter, as do shallow-water teredinids, although Xy- lophaga has been found embedded in the gutta-percha sheaths of submarine telegraph cables (PURCHON, 1941). There is some controversy over how wood is broken down and utilized by these organisms. Cellulase activity of sym- biotic bacteria located in the gland of Deshayes is thought to be the mechanism in some teredinid species (WATERBURY et al., 1983). Cellulase activity has been confirmed for Xylophaga dorsalis (PURCHON, 1941) although the source of this activity has not been determined. Since the advent of the New England offshore lobster fishing industry in the 1960s, Xylophaga atlantica has con- tributed significantly to the deterioration of the wooden Wiles Romey ei al 1991 42° -- . Cape oN 1 ee ie <=) 4\° 80 Sitel —— ae 10 Site II 40° BOY ee eas B95 Ue Ts 70° 69° Figure 1 Sampling Sites I and II off southeastern New England, USA. Depth contours in meters. lobster traps. Untreated traps are destroyed in less than one year, creating economic concerns for the fishermen (Dow, 1950). Although vinyl-covered wire-mesh traps are available, wood traps are preferred because of their low initial cost, repairability, perceived higher catch rates, and potentially longer length of service (DEALTERIS et al., 1988). BERG et al. (1987) recently reported temporal variability in the recruitment of several invertebrate species on Georges Bank, including the bivalve Xylophaga atlantica. The range of X. atlantica extends from the St. Lawrence estuary, at 48°N, south to Cape Henry, Virginia, at 36°N, in depths from 5 to 3000 m (TURNER, 1971). Other wood-boring pholads sympatric with X. atlantica include Xylophalas altenae Turner, 1972 and Xylophaga species 1, 2, 3, and 4 (BERG et al., 1987). Relative geographic and seasonal distribution and recruitment patterns are unknown for Xylophaga atlantica. The present study examined the sea- sonal recruitment of Xylophaga atlantica in the western North Atlantic at two New England sites. The objective of this study was to provide information on recruitment patterns of Xylophaga atlantica and to provide information to the fishermen on probable times of heaviest infestation of offshore wooden lobster traps. MATERIALS anp METHODS The Xylophaga samples were collected at two sites at the edge of the continental shelf south of Cape Cod (Figure 1). Site I was located at the 100-m contour (40°26’N, Page 15 70°28'W). Site II was situated at the 200-m depth contour (39°55'N, 69°44'W). Vinyl-coated wire-mesh racks, each containing 24 wood panels, were placed inside vinyl-coated wire lobster traps, which were fished in a trawl formation by participating offshore lobster fishermen (Figure 2). A trawl consisted of many traps tied at 30-m intervals along a single bottom line buoyed at each end. Two racks in each of two trawls (not more than 20 km apart) were deployed at each site. Each rack held 12 rough oak panels on one side and 12 rough-smooth pine panels on the other. Each panel was retained in a compartment in the rack with 1.0 cm clear- ance between panels for water to circulate. The panels were cut to a uniform size of 20 cm high x 8 cm wide x 2.5 cm thick. Only oak panels 2, 3, 4, 5, and 6 were used to estimate recruitment densities (Figure 2). Pine panels were used in a concomitant field study of small-scale larval settlement patterns (ROMEY, 1989). The racks were collected at intervals ranging from 29 to 212 days and the exact depth and location were recorded. The racks were stored in a circulating seawater tank on the vessel until their return to the docks several days later. The racks were then maintained in chilled seawater tanks while toxicological studies (DEALTERIS et al., 1988) were performed. After completion of these experiments, panels were preserved by desiccation. Recruitment is an observer-defined unit where the or- ganism attains a predefined size or age (KEOUGH & Downes, 1982). Recruitment and settlement are not iden- tical owing to a number of factors such as postlarval mor- tality (BUTMAN, 1987). In this paper, a recruited Xylopha- ga atlantica is one that has settled, undergone metamorphosis, and burrowed into the wood to form a visible bore hole. Subsequent mortality was not determined. Slight pits or depressions were counted only when animals were present. Losses from the manipulation of the panels were assumed to be the same for all samples. The density of specimens recruited per panel was ob- tained by counting the number of bore holes/cm*. The samples were taken using a diagonal transect method to survey all parts of the panel face equally. A measured cm? grid was laid over the panel face and 32 one-cm? areas/ face were examined (Figure 3). The sides of the panel were not counted owing to differential settlement patterns, as indicated by preliminary results from ROMEy (1989). Whole animals were later removed, identified, and mea- sured for a concomitant growth study (ROMEY, 1989). A recruitment rate index was then calculated in order to compare recruitment between panels and racks that had collected larvae for differing periods of time. This index (RI) is a rate function: RI = (AVG/T) x 100 where AVG is the average number of recruits/cm? for the rack and T is the time in days that the panel was on the sea floor. Panels within a rack were considered to be re- Page 16 The Veliger, Vol. 34, No. 1 OK XY) NARA Hrs OOO XK) RS ‘ RNR x? DOA XY \) anaes Figure 2 Vinyl-coated wire racks, each containing 24 wood panels, were placed inside vinyl-coated wire lobster traps, which were fished in a trawl formation. peated measures and variation between and within trawls in a site was found to be statistically insignificant (ANO- VA, P > 0.10; ROMEY, 1989). An average recruitment for the racks was calculated using panels 2, 3, 4, 5, and 6. The outside panel was not used in the average because it exhibited a significantly higher recruitment (ROMEY, 1989). RESULTS Xylophaga atlantica was the principal species encountered during this investigation. In Site II, an undescribed species of Xylophaga was occasionally found on the panels. No teredinid species were encountered. Identification of the specimens was provided by R. D. Turner. Voucher spec- imens have been deposited in the Museum of Comparative Zoology at Harvard University. Recruitment at Sites I and II ranged from an average of 0 to 30 animals/cm? depending on season and location. At Site I, 16 racks were collected over the two-year in- vestigation period (Table 1). Moderate recruitment (RI < 3) was observed between August and October 1987; low recruitment was observed from January 1987 to May 1988, and from September 1988 to July 1989. A peak in re- cruitment (RI > 9) occurred between September to De- cember 1987, with a smaller peak (RI = 4) from June to September 1988 (Figure 4a). Sixteen racks were retrieved at Site II. Data were not available from October 1987 to February 1988 owing to the loss of the sampling panels. Low recruitment (RI < 3) was observed in samples collected from September 1987 through January 1989. High recruitment occurred from January to May 1989 (RI = 19) with a maximum re- cruitment occurring from March through April 1989 (RI = 36) (Figure 4b). Recruitment patterns differed between the two sites. Significant differences (paired t-test, P = 0.25; SOKAL & Wenleenlwomey ci als, 1991 Figure 3 A measured cm? was laid over the panel face and 32 one-cm? areas were examined in a cross grid pattern. ROHLF, 1981) were observed for all sampling periods ex- cept for April to June 1988, when recruitment was low for both sites. The highest recruitment (RI = 36) occurred at Site II, whereas the highest recruitment measured at Site I reached only RI = 15. DISCUSSION The seasonal and geographical distribution of an organism is affected by two factors: its immediate environment and the particular life history that the organism has developed to live in the overall environment (WILLIAMS, 1975). Xy- lophaga is the first reported group of opportunistic organ- isms from the deep sea (TURNER, 1973). This group is characterized by high population densities, high fecundity, early maturity, rapid growth, delayed metamorphosis, and protandrous hermaphroditism (TURNER, 1973). Wood carried out to sea and sinking at variable rates and locations produces a patchy environment on the sea floor. However, the occurrence of wood at the bottom of the sea must be a predictable event (DAYTON & HESSLER, Page 17 1972) which allowed for the evolution of this entire sub- family of woodborers (TURNER, 1973). Sources of wood are many (including wood carried by rivers, canoes, boats, and lobster traps). Wood is probably not distributed ran- domly, but rather follows broad patterns based on currents and sources of wood. Most likely, the direction and mag- nitude of the currents regulate both the distributions of wood and pholad larvae. Near-bottom currents may play a role in small-scale recruitment patterns. The relationship between boundary layer flow and recruitment of barnacle cyprids was found to be highly significant (CRIsP, 1955). Differential post-settlement mortality might also be a fac- tor in the observed recruitment patterns (BUTMAN, 1987). Measurement of the currents from nearby sites (HOUGHTON et al., 1988) was used to calculate the poten- tial range of a passively drifting larva of Xylophaga atlan- tica. The average benthic current of 2.5 cm/sec could the- oretically move these organisms more than 2 km/day or up to 70 km/month in a southeastly direction. CULLINEY & TURNER (1976) kept larvae alive in the laboratory for two months without the larvae undergoing metamorphosis. During this time, they would have been capable of trav- eling more than 140 km with the currents. If the larvae were able to migrate vertically, they would be able to select currents that transport them into areas with suitable sub- strate and perhaps even return them to the general location where spawning had occurred. Slow development and de- layed metamorphosis at colder temperatures might also enhance dispersal capabilities of the larvae (PECHENIK, 1980). Although the actual settlement of Xylophaga atlantica has never been observed in the laboratory, development of the larvae from the fertilized egg to the pediveliger (set- tlement stage) has been reported. CULLINEY & TURNER (1976) reported that X. atlantica releases eggs when the temperature rises from 4°C to 9°C. BERG et al. (1987) reported gonadal ripening of Xylophaga in late summer when the temperature exceeds 10°C. CULLINEY & TURNER (1976) predicted a long larval planktonic stage, and sug- gested that the larvae probably would not settle and un- dergo metamorphosis until the fall or winter. Although data on temperature are not available for the two study sites, it has been suggested that seasonal vari- ations do occur on the bottom. HOUGHTON et al. (1988) reported a peak of 14°C in late November and a low of 5°C in February in a site located south of Cape Cod on the shelf-slope interface at a depth of 75 m. A three-year time series of temperatures on Georges Banks collected by BERG et al. (1987) also supports these observations. Station Q from BERG et al. (1987) coincides with our present Site I. If seasonal tendencies are assumed to be similar year to year, these temperatures can be compared to those affecting Xylophaga recruitment at Site I. A steady rise in mean bottom temperature occurred from February through Oc- tober, reaching a peak of 15°C in November. The tem- perature rose above 10°C from August through October, corresponding to peak recruitment at Site I during 1987. Page 18 The Veliger, Vol. 34, No. 1 INDEX (RI) RECRUITMENT 1987 Figure 4 Recruitment indices (RI) at Sites I (a) and II (b). Data are plotted over the period of panel submergence. Recruitment index is the average number of recruits/cm? divided by the number of days on the sea floor, multiplied by 100 (see text). A smaller peak was observed from July to September 1988. Slight yearly temperature variations might account for these shifts in peak recruitment. At depths of approximately 200 m at the edge of the continental shelf, the temperature ranges from 10 to 12°C shout the year (BEARDSLEY et al., 1985; HOUGHTON 1988). Temperature would not be a good physical trigger to initiate spawning in these areas because it does not have a regular annual variance. Other environmental cues affecting the benthos could be chemical or light that might penetrate to some extent. Plankton are believed to supplement the nutritional requirements of teredinids (PECHENIK et al., 1979) and some species can grow and reproduce only when their wood diet is supplemented with W. L. Romey e¢ ai., 1991 Page 19 Table 1 Summary of the data obtained from the two collection sites. (Duration = number of days panels were subjected to recruitment at sea floor; AVG = average number of recruits per 4 cm? (n = 80); SE = standard error of the mean (n = 80); RI = recruitment rate index, which equals (avg/4)/days x 100. Site Dates Duration (days) I 12 Aug. 87-22 Sep. 87 40 40 12 Aug. 87-19 Oct. 87 68 68 22 Sep. 87-22 Dec. 87 92 92 19 Oct. 87-22 Dec. 87 64 64 22 Dec. 87-13 May 88 143 143 143 143 19 Jun. 88-8 Sep. 88 51 8 Sep. 88-18 Oct. 88 41 18 Oct. 88-7 Dec. 88 51 7 Dec. 88-6 Jul. 89 212 II 10 Sep. 87-15 Oct. 87 35 35 10 Feb. 88-10 Mar. 88 29 29 10 Feb. 88-24 Apr. 88 75 VS 10 Mar. 88-24 Apr. 88 45 45 24 Apr. 88-7 Jun. 88 44 44 7 Jun. 88-4 Aug. 88 58 11 Sep. 88-13 Oct. 88 31 13 Oct. 88-7 Dec. 88 56 7 Dec. 88-20 Jan. 89 45 20 Jan. 89-11 Mar. 89 51 11 Mar. 89-24 Apr. 89 45 phytoplankton (KARANDE et al., 1968). Plankton may play a role in Xylophaga nutrition, growth, and spawning, that is currently undiscovered. ACKNOWLEDGMENTS The authors gratefully acknowledge the guidance provided by Dr. R. D. Turner in the development of this investi- gation. Her assistance in species identification, method- ologies, and data analysis was invaluable. Support for this project was provided by the Rhode Island Sea Grant Program, the College of Resource De- velopment, Agricultural Experiment Station, and the Col- lege of Arts and Sciences, Department of Zoology. The authors gratefully acknowledge the assistance of Captain Paul Bennett and the crew of the F/V Heddy Brenna and Captain Al Eagles and the crew of the F/V Catherine Anne. The F/V Reliance and all her crew were lost in November 1987 while tending traps and collecting samples Rack Avg SE RI 8a OM 0.27 1.23 2a 2.34 0.23 1.46 3a 5.25 0.44 1.93 7a 5.85 0.39 2.15 8b 29.37 1.32 7.98 2b 36.67 1.87 9.96 3b 32.24 2.16 12.59 7b 57.03 2.86 22.28 8c 1.85 0.24 0.32 2c 2.04 0.25 0.35 3c 1.45 0.19 0.25 7c 4.54 0.50 0.79 8e 8.03 0.54 3.94 2f 0.36 0.01 0.22 8g 3.35 0.43 1.64 2h 3.35 0.39 0.39 4a 0 0 0 5a 0 0 0 4b 2.35 0.26 2.03 5b 2.35 0.26 2.03 la 4.86 0.41 1.62 6a 8.81 0.57 2.94 4c 2.87 0.28 1.60 5¢ 6.73 0.43 3.74 4d 0.78 0.12 0.44 5d 2.18 0.28 1.24 4e 0.25 0.01 0.11 4h 0.48 0.01 0.38 4i 1.65 0.18 0.74 4j 3.07 0.29 1.71 4k 38.32 2.28 18.78 51 64.70 2.34 35.94 for this study. Deepest sympathies are extended to the families of the captain and crew. This is contribution number 2536 of the University of Rhode Island, College of Resource Development, Agri- cultural Experiment Station, Kingston, Rhode Island 02881, USA. LITERATURE CITED BEARDSLEY, R. C., D. C. CHAPMAN, K. H. BRINK, S. R. RAMP & R. SCHLITZ. 1985. The Nantucket Shoals flux experi- ment (NSFE79). Part I: A basic description of the current and temperature variability. Journal of Physical Oceanog- raphy 15:713-748. BERG, C. J., JR., B. Burman, J. A. EARLY & R.D. TURNER. 1987. Seasonal recruitment of marine invertebrates to hard substrates on Georges Bank and the eastern continental shelf of the United States. Nautilus 101:19-24. BuTMAN, C. A. 1987. Larval settlement of soft-sediment in- vertebrates: the spatial scales of pattern explained by active Page 20 The Veliger, Vol. 34, No. 1 habitat selection and the emerging role of hydrodynamic processes. Oceanography and Marine Biology Annual Re- view 25:113-165. Crisp, D. J. 1955. The behavior of barnacle cyprids in relation to water movement over a surface. Journal of Experimental Biology 32:569-590. CuLuiney, J. L. & R. D. TURNER. 1976. Larval development of the deep-water wood-boring bivalve, Xylophaga atlantica Richards (Mollusca, Bivalvia, Pholadidae). Ophelia 15:149- 161. DayTon, P. K. & R. R. HESSLER. 1972. The role of biological disturbance in maintaining diversity in the deep sea. Deep- Sea Research 19:199-208. DEALTERIS, J. T., R. C. BULLock & W. L. ROMEy. 1988. Alternative treatments to prevent the biodeterioration of off- shore wood lobster traps by the wood-boring bivalve, Xy- lophaga atlantica. Journal of Shellfish Research 7:445-451. Dow, R. L. 1950. Trap destruction by borers increasing in some areas. Maine Coast Fisherman, September 1950, p. 4. HouGutTon, R. W., F. AIKMAN III & W. Ou. 1988. Shelf- slope frontal structure and cross-shelf exchange at the New England shelf-break. Continental Shelf Research 8:687-7 10. KARANDE, A. A., K. BALASUBRAMANIAN & S. PREMA. 1968. Development of a laboratory method for bioassay of can- didate toxins against teredinid wood-borers. Jn: Symposium on Mollusca. Part III. Marine Biological Association of In- dia. KEouGH, M. J. & B. J. Downes. 1982. Recruitment of marine invertebrates: the role of active larval choices and early mor- tality. Oecologia (Berlin) 54:348-352. KNUDSEN, J. 1961. The bathyal and abyssal Xylophaga. Gal- athea Report 5:163-209. PECHENIK, J. A., F. E. PERRON & R. D. TURNER. 1979. The role of phytoplankton in the diets of adult and larval ship- worms Lyrodus pedicellatus (Bivalvia: Teredinidae). Estu- aries 2(1):58-60. PECHENIK, J. A. 1980. Growth and energy balance during the larval lives of three prosobranch gastropods. Journal of Ex- perimental Marine Biology and Ecology 44:1-28. PERKINS, E. J. 1974. Fouling and boring organisms. Jn: E. J. Perkins (ed.), The Biology of Estuaries and Coastal Waters. Academic Press: New York. 678 pp. PURCHON, R. D. 1941. On the biology and relationships of the lamellibranch Xylophaga dorsalis (Turton). Journal of the Marine Biological Association of the United Kingdom 25(1): 1-39. RomeEy, W. L. 1989. Recruitment and growth of Xylophaga atlantica. Master’s Thesis, University of Rhode Island, Kingston. 113 pp. SoKAL, R. R. & E. J. ROHLF. 1981. Biometry: The Principles and Practice of Statistics in Biological Research. W. H. Freeman and Company: New York. 859 pp. TURNER, R. D. 1971. Identification of marine wood-boring molluscs. Jn: E. B. G. Jones & S. K. Eltringham (eds.), Marine Borers, Fungi and Fouling Organisms of Wood. 1. Organization for Economic Co-operation and Development, Paris. TURNER, R. D. 1973. Wood-boring bivalves, opportunistic spe- cies in the deep sea. Science 180:1377-1379. TURNER, R. D. 1977. Wood, molluscs and deep-sea food chains. Bulletin of the American Malacological Union Inc. for 1977: 13-19. WATERBURY, J. B., C. B. CALLOWAY & R. D. TURNER. 1983. A cellulolytic nitrogen-fixing bacterium cultured from the gland of Deshayes in shipworms (Bivalvia: Teredinidae). Science 221:1401-1403. WILLIAMS, G. C. 1975. Sex and evolution. Jn: R. M. May (ed.), Monographs in Population Biology 8. Princeton Uni- versity Press: Princeton, New Jersey. 200 pp. The Veliger 34(1):21-31 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 Functional Anatomy of Castalia undosa undosa (Martens, 1827) (Bivalvia: Hyriidae) by WAGNER E. P. AVELAR AnD SANDRA C. D. SANTOS Department of Biology, Faculty of Philosophy, Sciences and Letters of Ribeirao Preto, University of Sao Paulo, 14049 Ribeirao Preto, SP, Brazil Abstract. Castalia undosa undosa, Martens, 1827, is a member of the family Hyriidae, the distribution of which is restricted to South America. In Brazil the species occurs in the center-south region, corre- sponding to the upper Parana River. These medium-sized mollusks live buried in muddy substrata, are slightly heteromyarian, and are dioecious, with sexual dimorphism evident in the shell conformation. The siphons are simple (type AII of Yonge, 1957), and mantle fusion occurs only through the inner fold. The incurrent siphon has tentacles originating from the inner fold and the excurrent siphon exhibits a few tubercles, probably of sensory function. The ctenidia are of type D (of Atkins, 1937). Internally, females possess a well-developed marsupium in the inner demibranch in which eggs are incubated. The stomach is a type IV structure (of Purchon, 1958), and is quite uniform when compared to that encountered in other freshwater bivalve families. INTRODUCTION The South American family Hyriidae Fleming, 1828, is represented by a single subfamily, Hyriinae Swainson, 1840, with two tribes, Castaliini and Diplodontini, both of Parodiz & Bonetto, 1963. Of the five genera belonging to the tribe Castaliini which, according to BONETTO (1965), is widely distributed throughout the South American con- tinent and particularly in Brazil, only three were detected by LANGE DE MorreETEs (1949)—2.e., Castalia, Castalina, and Callonaia—whereas Chevronais and Castaliella were not mentioned. In a review of the tribe Castaliini, BONETTO (1965) discussed the value of the different genera and concluded that only Castalia and Callonaia should be con- sidered, admitting the introduction of subgeneric categories only in the genus Castalia. Thus, according to BONETTO (1965), Castalia undosa Martens, 1885, has two subspe- cies; C. ambiqua Lamarck, 1819, has four subspecies; and C. psammoica Orbigny, 1835, and C. sulcata Krauss, 1849 have three subspecies each; Callonaia has only the species C. dupre: Recluz, 1843. Among the papers available on the anatomy of South American Unionacea, particularly outstanding are those by MANsUR (1972, 1973), HEBLING & PENTEADO (1974), HEBLING (1976), and MANSUR & ANFLOR (1981). Other investigators, in studies on the ge- nus Castalia, have referred only to branchial openings, ctenidia, palps, and muscles (IHERING, 1891, 1893; ORTMANN, 1921; BONETTO, 1961, 1965). The goal of the present investigation was to study the structure, ciliary currents for feeding and digestion, and other functional adaptations of the subspecies Castalia un- dosa undosa Martens, 1827, providing information on the anatomy of the limnic fauna of South American bivalves and systematic data that may help distinguish species and subspecies of the genus Castalia. MATERIALS anD METHODS Living specimens of Castalia undosa undosa were collected in the Pardo River at the municipality of Ribeirao Preto (2197'S, 47°45'W). Approximately 66 animals were cap- tured throughout the study and carried to the laboratory, where they were kept alive in appropriate aquaria at 25°C. A few animals were anesthetized with magnesium chloride and then fixed in 10% formol, Bouin’s, or 70% alcohol for morphological examination. To complement the anatom- ical studies, detailed drawings of the animals and of the arrangement of their inner organs were made using live, anesthetized specimens. The ciliary currents of the mantle, ctenidia, labial palps, and stomach were observed under a stereoscopic microscope using carmine or carborundum suspensions as indicators. Sections (7-10 wm thick) were The Veliger, Vol. 34, No. 1 1cm lv Figure 2 Castalia undosa undosa, external view of the left valve showing the lines of growth and ribs. A. Male. B. Female. lv, left valve. prepared from structures fixed in Bouin’s and stained with Ehrlich’s hematoxylin and eosin. HABITAT According to BONETTO (1965), Castalia undosa undosa Martens, 1827, is found in the basin of the upper Parana River, whereas the other subspecies, C. undosa martensi Ihering, 1891, is limited to the rivers of the South Atlantic coast of Brazil and to Uruguayan waterways. Figure 1 Castalia undosa undosa, animals in their natural habitat. A. Ex- ternal view of the left side showing extended foot. B. Frontal view. es, excurrent siphon; is, incurrent siphon; 1, ligament; rb, rib. W. E. P. Avelar & S. C. D. Santos, 1991 Page 23 Figure 3 Castalia undosa undosa, internal view of the right valve, showing the muscles scars. aam, anterior adductor muscle; arm, anterior retractor muscle of foot; ct, cardinal tooth; |, ligament; lu, lunule; It, lateral tooth; pam, posterior adductor muscle; pl, pallial line; pm, protractor muscle; prm, posterior retractor muscle; u, umbo. Castalia undosa undosa lives buried at sites with muddy substrata, generally under the shade of bushes and trees, or among the roots of aquatic plants. According to MANSUR (1972), C. undosa martensi preferentially lives near rushes in substrata where fine sand predominates. Specimens of Castalia undosa undosa were collected at depths ranging from 0.70 cm to 1 m, in relatively calm waters. The animals burrow almost completely into the substratum (Figure 1A, B) and can be captured only by probing the river bottom with one’s feet or hands. Several bivalve species were found at the Pardo River: Diplodon rotundus gratus Wagner, 1827; Anodontites trapesialis La- marck, 1819; A. trapezeus Spix, 1827; and A. crispatus Orbigny, 1835. Two species of Diplodon and one of Mono- condylea that could not be identified at the species level were also found. Large numbers of limnic acarids were observed in the branchiae of the animals studied; these probably belong to the genus Unionicola, subgenus Pen- tatax, and were mentioned by HEBLING (1976). FUNCTIONAL ANATOMY Shell The shell of Castalia undosa undosa (Figure 2A, B) is subtriangular, equivalve, and inequilateral, with a prom- inent upper ridge that is truncated in the posterior region. The umbo (u) is prosogyrate with a worn periostracum. The lunule (Figure 3, lu) is easily visible, oval, and dark in color. The outer opistodetic ligament (1) is also easily visible. In the dorsal area of the shell where the valves meet, and extending almost the entire length of the hinge, fused periostracal layers can be easily seen in specimens larger than 4 cm. Figure 4 Castalia undosa undosa, organs and ciliary currents of mantle cavity after removal of left shell valve and mantle lobe. a, anus; aam, anterior adductor muscle; arm, anterior retractor muscle of foot; au, auricle; dd, digestive diverticula; es, excurrent siphon; f, foot; id, inner demibranch of ctenidia; ilp, inner labial palp; is, incurrent siphon; k, kidney; It, lateral tooth; m, mantle; od, outer demibranch of ctenidia; olp, outer labial palp; p, perios- tracum; pam, posterior adductor muscle; pc, pericardium; pm, protractor muscle; prm, posterior retractor muscle; rc, rectum; u, umbo; v, ventricle; vm, visceral mass. The edges of the shell meet throughout their extension, leaving no opening. The outer surfaces of specimens measuring up to 6 cm in length are sculptured with 8 to 13 ribs (Figure 1, rb) arranged almost in parallel but converging in the umbonal region. In larger specimens, the ribs are worn off, and only the growth lines are visible. In the posterior shell region there is marked sculpturing, with folds and nodules delimiting the anterior ribs. According to BONETTO (1965), these characteristics are distinct, indicating that this is a well-characterized subspecies. The periostracum (Figure 4, p) of Castalia undosa undosa is dark brown in color, with marked abrasion in the um- bonal region that is clearly visible in adult specimens. A notable characteristic of this species is that the shell has successive layers of periostracum and a thin underlying prismatic layer within the common mass of the inner cal- careous layer of the valves. This characteristic was also observed by TAyLor et al. (1969) in the Unionaceae and in the Hyriidae and Mycetopodidae collected during our studies. The umbonal abrasion is due to the velocity of the current passing over the animals, and to the nature of the substratum and the chemical composition of the water (BONETTO, 1963). Castalia undosa undosa is sexually dimorphic, the males being distinguished by the posterior beak of the shell (Fig- ure 2A, B), which is more tapered, and by having a de- pression in the posteroventral shell region. Figure 5 Castalia undosa undosa, lateral view of right valve musculature after removal of left valve, mantle, palps, and visceral mass. aam, anterior adductor muscle; arm, anterior retractor muscle; ct, car- dinal tooth; dm, dorsal muscle; It, lateral tooth; pam, posterior adductor muscle; pm, protractor muscle; prm, posterior retractor muscle; u, umbo. The inner surface of the valves (Figure 3) is smooth and white in color. The hinge is well developed, with two cardinal teeth (ct) in each valve. The anterior cardinal tooth is larger than the posterior one, with several well- developed cusps. The outer and inner surfaces of the car- dinal teeth of the left valve are crenulated, while on the right valve the crenulation is present only on the inner surface. In the right valve there is a lateral tooth with both surfaces showing crenulation, and in the left valve there is a facet of equal size whose inner surfaces are crenulated. The pallial line (pl) starts below the scar of the anterior adductor muscle (aam) and extends posteriorly parallel to the shell margin, describing a curve that terminates at the base of the scar of the posterior adductor muscle (pam). The scars of the adductor muscles vary in size according to specimen length, the posterior one being slightly longer than the anterior one. The anterior retractor muscle of the foot (arm) is located dorsolaterally to the anterior adductor muscle (aam), which is small and deep. Ventrally to the anterior adductor muscle is located the protractor muscle of the foot (pm), of slightly triangular contour and pro- portional in size to the anterior retractor muscle. The scar of the posterior retractor muscle (prm), which is rounded in shape and similar in size to the anterior retractor muscle, is located dorsally to the posterior ad- ductor muscle. The dorsal, or elevator, muscles (Figure 5, dm): leave obvious scars in the valves, which, however, are difficult to see because of their location on the inner surface of the hinge in the umbonal cavity. The number of scars detected in Castalia undosa undosa ranged from 3 to 6. Elevator muscles have also been observed in Leila blainvilleana The- ring, 1890 (BONETTO, 1963), Diplodon rotundus gratus The Veliger, Vol. 34, No. 1 (HEBLING & PENTEADO, 1974), and Anodontites trapesialis (HEBLING, 1976). Mantle By removing the animal’s left valve (Figure 4) and the left mantle lobe, the pallial cavity is exposed. The three folds of the mantle margin are small; the medial one (sen- sory) and the outer one (secretory) are very close to one another. In the posterior region, the inner fold (muscular) bears two rows of small tentacles arranged at the entrance to the incurrent siphon. According to MORTON (1978), these tentacles have a sensory function and apparently take on the function of the middle fold. The mantle surface is uniformly cream colored, except for the region of the in- current and excurrent siphons, where the mantle is dark cream colored. The mantle lobes are usually free, except posteriorly where they are joined by an inner fold that separates the incurrent from the excurrent siphon and promotes the joining of the ctenidium through tissue fusion. Approxi- mately 65% of the specimens studied had a second joining point that is below the incurrent opening and which sep- arates the incurrent opening from the pedal opening. The ciliary currents of the mantle surface are illustrated in Figure 11 and are similar to those described by HEBLING & PENTEADO (1974) for Diplodon rotundus gratus, and by HEBLING (1976) for Anodontites trapesialis and A. trape- zeus. Siphons The siphons of Castalia undosa undosa are of type AII (YONGE, 1957), and are formed by the fusion of the inner fold of the mantle due to tissue joining. The incurrent siphon (is) is complete in most animals. However, incom- plete siphons were observed in approximately 35% of the specimens. In C. undosa martensi, IHERING (1891) found that 1 of 8 specimens had an incomplete incurrent siphon, and MANSuR (1972) found the same phenomenon in 2 of 40 specimens. On the inner margin of the incurrent siphon there are 23 to 85 simple, conically shaped tentacles, some of which may eventually bifurcate. They are arranged along two rows, an inner one and an outer one, the larger and darker tentacles being in the inner row. In Castalia undosa martensi there are three rows of ten- tacles, varying in number from 80 to 180 (MaNsurR, 1972). The excurrent siphon, which is dark cream in color and has slightly undulating margins, has no tentacles. Wrin- kles, spots, and small tubercles, varying in number from 1 to 8, may appear externally at the base of the siphon. Among the Hyriidae and the Mycetopodidae studied thus far, the occurrence of these tubercles has been reported only for Castalia undosa martensi by MANSUR (1972). The sensitive siphon of Castalia undosa undosa, and other bivalves, which has been attributed by several investigators W. E. P. Avelar & S. C. D. Santos, 1991 yy Figure 6 Castalia undosa undosa, labial palps of left side. Arrows show direction of ciliary currents. ac, anterior channel; ag, anterior groove of mantle; g, marginal groove of inner demibranch; id, inner demibranch; ilp, inner labial palp; m, mantle; olp, outer labial palp. to the fact that these animals live in calm waters (OWEN, 1953; NARCHI, 1972a; HEBLING, 1976), was confirmed in the present study. Muscles and Foot In terms of muscle fiber arrangements and insertions on the valve, the musculature of Castalia undosa undosa (Fig- ure 5) is similar to that of members of the Unionidae, Hyriidae, and Mycetopodidae (MANsUR, 1972; HEBLING & PENTEADO, 1974; HEBLING, 1976). The presence of dorsal muscles (dm), varying from 3 to 6 in number, is particularly clear in medium-sized and large specimens. These muscles were observed by BONETTO (1963) in Leila blainvilleana and by HEBLING (1976) in Anodontites tra- pestalis. According to HEBLING (1976), these muscles cor- respond to the elevator muscles of Brtick described for Anodonta cellensis. The foot (f) has no cilia, as was also observed in fresh- water bivalves studied by other investigators, such as Mansur (1972), HEBLING & PENTEADO (1974), and HEB- LING (1976). Mantle Cavity Topography: The positions of the main organs of the mantle cavity are indicated in Figure 4. The visceral mass region is the first to be distinguished. This milky white and intensely ciliated region is responsible for rejectory Page 25 aaqm MI 3 mm Figure 7 Castalia undosa undosa, structure and ciliary currents of ctenidial- labial palp junction as viewed from left side. aam, anterior ad- ductor muscle; ac, anterior channel; ag, anterior groove of mantle; f, foot; g, marginal groove of inner demibranch; id, inner demi- branch; ilp, inner labial palp; mo, mouth; olp, outer labial palp; pog, proximal oral groove. currents that carry particles to the posterior region of the animal. Next are the foot, which is yellowish in color and has no cilia, and the ctenidia, which extend posteriorly from the umbonal region to the base of the siphon process, where the process is fixed at the inner fold of the mantle. There is no supra-axial region. The mantle margins, ob- served next, may fuse or not at the base of the incurrent siphon, leaving a wide pedal opening that can be contin- uous or not with the incurrent siphon (is). Finally, there are the labial palps (ilp), which are large and slightly oval in shape. Labial palps: In Castalia undosa undosa, the palps (Figure 6) are cream colored and symmetrical, with folded inner surfaces and smooth outer surfaces. An area with no folds exists on the inner surfaces (Figure 7), both in the anterior and posterior regions. The anterior region is connected to the proximal oral groove (pog) and the posterior region to the anterior channel (ac). The food particles that reach the labial folds originate from the marginal food groove (g) of the inner demibranch, either from the anterior channel, which directs the particles orig- inating from acceptance currents of the outer demibranch, or from the anterior mantle groove (ag), which sends the particles from the mantle to the dorsum of the outer labial palp. This last current was observed by MANSUR (1972) in Castalia undosa martensi. The mechanisms of particle screening and acceptance on the part of the labial palps are similar to those observed by HEBLING & PENTEADO (1974) and HEBLING (1976). The Veliger, Vol. 34, No. 1 Figure 8 Castalia undosa undosa, diagrammatic vertical section through cte- nidium to show direction of beat of frontal cilia. alid, ascending lamella of inner demibranch; alod, ascending lamella of outer demibranch; dlid, descending lamella of inner demibranch; dlod, descending lamella of outer demibranch; id, inner demibranch; od, outer demibranch. Ctenidia: The ctenidia of Castalia undosa undosa (Figure 8) are of type D (ATKINS, 1937), 7.e., characterized by the absence of a marginal groove in the outer demibranch. According to ATKINS (1937), this type of ctenidium is characteristic of the Unionidae, though it has also been found in the Hyriidae (MANsuUR, 1972; HEBLING & PENTEADO, 1974), Mycetopodidae (HEBLING, 1976), and Sphaeriidae (MANSUR & VEITENHEIMER, 1975). All in- dications are that the type D ctenidium is characteristic of freshwater bivalves. The ctenidia of Castalia undosa undosa and C. undosa martensi originate in the subumbonal region and project toward the siphon region. They are arranged diagonally in relation to the visceral mass. The anterior filaments of the outer demibranch (Figure 4, od) are smaller than those of the inner demibranch and increase gradually in size posteriorly (Figure 4). The inner demibranch (id) grows anteriorly in relation to the mantle and visceral mass, forming a wide and easily visible anterior channel (ac) that ends in the dorsal region of the labial palps (Figures 6, 7). The demibranchs are formed by shallow folds, with filaments varying in number 52 in the ascending lamella (alod) and from he descending lamella (dlod) of the outer od). In the inner demibranch (id), the number Figure 9 Castalia undosa undosa, transverse sections through a portion of outer (A) and inner (B) demibranchs showing arrangement of folds and filaments. id, inner demibranch; od, outer demibranch. of filaments varies from 26 to 39 in the descending lamella (dlid) and from 22 to 40 in the ascending lamella (alid) (Figures 8, 9A, B). In female specimens and in the few living hermaphro- dites, the characteristic marsupium of freshwater bivalves is detected in the inner demibranch, but is visible only when the animals are in the reproductive cycle. The ciliation of Castalia undosa undosa (Figure 10A, B) is similar to that of Diplodon rotundus gratus (HEBLING & PENTEADO, 1974), Anodontites trapezeus, and A. trapesialis (HEBLING, 1976). The frontal cilia (fc) are approximately 3.3 wm long, and the terminal cilia (tc) are 6.6 wm long in the inner demibranch and 3.3 wm in the outer demibranch. The eulaterofrontal cilia (lfc) are 13.4 um long, and the lateral cilia (Ic) 9.8 wm. The ciliary currents observed on the branchial surface are illustrated in Figure 8. W. E. P. Avelar & S. C. D. Santos, 1991 ee ee APL AU . | Ic mr 0,05 mm SS Figure 10 Castalia undosa undosa. A. Cilia on outer surface of inner demi- branch. B. Transverse section of two filaments of inner demi- branch to show cilia. Arrows indicate direction of ciliary currents, including the oral one. fc, frontal cilia; lc, lateral cilia; lfc, lateral frontal cilia; tc, terminal cilia. Ciliary Currents of the Mantle The ciliary currents of the inner mantle surface (Figure 11) run in an anteroventral direction up to the ventral region of the anterior adductor muscle. This current is Page 27 Figure 11 Castalia undosa undosa, inner surface of right mantle lobe to show ciliary cleansing currents. aam, adductor anterior muscle; ct, car- dinal tooth; es, excurrent siphon; is, incurrent siphon; It, lateral tooth; m, mantle; pam, posterior adductor muscle; prm, posterior retractor muscle; u, umbo. associated with the rejectory tract of the mantle lobe, which runs in a posterior direction. This tract also receives par- ticles from the pedal opening. The rejectory tract originates in the ventral region of the anterior adductor muscle where the labial palps are intensely active in screening and re- jecting particles that fall in this region. The tracts of the two mantle lobes join at the bases of the incurrent siphon, where pseudofeces are periodically eliminated. Similar currents occur in members of the Unionidae (KELLOGG, 1915), Hyriidae (HEBLING & PENTEADO, 1974), and My- cetopodidae (HEBLING, 1976). Ciliary Currents in the Visceral Mass The ciliary currents in the dorsal region of the visceral mass run in a ventral direction. At the border between the visceral mass and the foot there is a rejectory tract that sends the particles rejected by the labial palps and inner demibranch to the posterior region (Figure 4). The cur- rents running in the ventral direction join those of the rejectory tract and so the rejected particles are sent toward the posterior end of the visceral mass where they fall in the rejectory tract of the mantle. Similar rejectory tracts have been detected in the visceral mass of marine bivalves such as the Petricolidae (NARCHI, 1975; MORTON, 1978). Alimentary Canal The general topography of the digestive tract is illus- trated in Figure 12. The mouth (mo) is located in the posteroventral region of the anterior adductor muscle. The mouth is followed by an esophagus (oe) whose inner wall has grooves and folds that are interrupted at the entrance to the stomach by a The Veliger, Vol. 34, No. 1 oam mo Figure 12 Castalia undosa undosa, alimentary canal seen from left side. The numerals 1, 2, 3, and 4 denote major subdivisions in the gut posterior to the stomach. a, anus; aam, anterior adductor muscle; dd, digestive diverticula; f, foot; gn, gonad; mo, mouth; oe, esoph- agus; pam, posterior adductor muscle; rc, rectum; s, stomach; v, ventricle. transverse ridge (Figure 13, rm). The stomach is located in the anterodorsal region of the visceral mass and is en- veloped by digestive diverticula. The stomach of Castalia undosa undosa is of type IV (PURCHON, 1958), as it is in the Unionidae (GRAHAM, 1949; PURCHON, 1958; DINAMANI, 1967), Mycetopodidae (HEBLING, 1976; VEITENHEIMER & MANsuR, 1978), and Hyriidae (MANsUR, 1972; HEBLING & PENTEADO, 1974; and MANSUR & ANFLOR, 1981). The general morphology of the stomach, the complexity of the ciliary currents and screening areas, and the con- jugated intestinal and crystalline style sac (ss) apertures (Figure 13) are similar to those observed in the bivalve families studied by the investigators cited above. The gut of Castalia undosa undosa is divided into three regions. The aperture of the style sac is associated with the first region, which extends through a posterior loop to the opening of the stomach (Figure 12, 1-2). The second region (23) consists of two loops of mid-gut, the lumen of which has a conspicuous typhlosole. The third region (3-4) is an extensive loop terminating in the anus. The rectum occupies a reasonably large area of the visceral mass, and has a developed typhlosole. The arrangement ihe gut in the visceral mass follows the pattern of Hy- such as C. undosa martensi (MANSUR, 1972), Diplo- lon rotundus gratus (HEBLING & PENTEADO, 1974), D. char Orbigny, 1835, and D. pilsbry: Marshall, 1928 (MA R \.NFLOR, 1981). Pericardium, Heart, Kidney, and Gonads The pericardium is a wide structure located below the posterodorsal region of the shell. The heart consists of a ventricle, two auricles, and an aortic bulb. Brown tissue on the anterior wall of the pericardium denotes the pres- ence of the pericardial gland, which is similar to that of Anodonta (WHITE, 1942). The rectum crosses the entire length of the ventricle, entering it in the usual manner, 1.e., ventrally to the anterior aorta. The kidney extends posteroventrally to the pericardium and is essentially similar to that of Anodonta (WHITE, 1942; YONGE, 1978). In Castalia undosa undosa, hermaphroditism is rare, and was present in only 2 of 66 individuals studied. The male or female follicles are arranged along the entire visceral mass that envelops the digestive tract. DISCUSSION Studies of the functional anatomy of Castalia undosa undosa have revealed the existence of anatomical similarities among the Hyriidae, Mycetopodidae, and Unionidae studied by different investigators. Castalia undosa undosa lives in muddy substrata similar to those inhabited by C. inflata, but differing in this respect from C. undosa martensi (MANSUR, 1972) and C. psammoica (BONETTO, 1961), which live on sandy bottoms. In general, studies on freshwater bivalves have shown few special adaptations to the habit of living close to the surface in relatively soft substrata and feeding on particles in suspension. This fact was also pointed out by ANSELL (1961) for marine bivalves. According to OWEN (1953), many of the adaptations of bivalves that filter particles in suspension (Solenidae and Myiidae) are correlated with their habit of burrowing deeply, with a consequent loss of horizontal mobility. The ability to burrow into soft substrata and to occupy the same site for long periods of time, which is true for Castalia undosa undosa as well as Anodontites trapesialis (HEBLING, 1976), may be associated with the lack of func- tionality of the elevator muscles, which are underdeveloped in these animals and absent in others, such as A. trapezeus (HEBLING, 1976). NARCHI (1978) proposed that functional elevator muscles help the animals burrow in compacted substrata, as is the case with Donax, which is frequently uncovered by the action of waves. Castalia undosa undosa has relatively simple tentacles. Studying marine bivalves, NARCHI (1972b) attributed the simplicity of the siphons of Anomalocardia to the fact that the animals live in calm waters and feed on particles in suspension. Similarly, C. undosa undosa lives in calm waters and feeds on suspended particles. According to BONETTO (1961), the presence of a muscle septum separating the pedal orifice from the incurrent orifice is an almost constant feature in the genus Castalia. The absence of a muscular septum in C. undosa undosa is W. E. P. Avelar & S. C. D. Santos, 1991 Page 29 Pos. mt (ins as mn il Mi DEY | ee ig aN N WY )\ Vy, oe Figure 13 Castalia undosa undosa, structure of interior of stomach opened by middorsal incision. Arrows show direction of ciliary currents. ant, anterior; c, conical protuberance of floor of stomach; ddd1, orifice of left duct of digestive diverticula; ddd2, orifice of right duct of digestive diverticula, dh, dorsal hood; gs, gastric shield; ig, intestinal groove; Ip, left pouch; mt, minor typhlosole; oe, esophagus; pos, posterior; r, ridge passing from esophageal orifice over roof of dorsal hood; rm, transverse ridge; rt, ciliated rejectory tract; sa3, principal sorting area of dorsal hood; sa7, sorting area below esophageal orifice; sa8, sorting area on anterior roof of stomach; ss, orifice of style sac and mid-gut; ty, major typhlosole. relatively frequent (35%) when compared with other spe- cies in the genus, for which the highest frequency otherwise recorded was 5%, for C. undosa martensi (MANSUR, 1972). The branchial cilia (lateral, frontal, terminal, and eu- laterofrontal cilia) of Castalia undosa undosa are small when compared with those of the marine bivalves living in tur- bulent waters studied by NARCHI (1974). However, they are similar to those of freshwater bivalves living in the same type of environment, such as Anodontites trapezeus and A. trapesialis (HEBLING, 1976), and they are propor- tionally smaller when compared with the cilia of Diplodon rotundus gratus (HEBLING & PENTEADO, 1974) which lives in sandy substrata. Thus, the presence of relatively short cilia may be associated with the animals’ habit of living in muddy environments with large amounts of very fine particles in suspension, such as silt, clay, and monocellular phytoplankton. Another adaptation that can be attributed to a muddy type of environment is the marked development of the labial palps, which, according to YONGE (1949), is common in animals burrowing in muddy substrata. According to HEBLING (1976), the complexity of the ciliary currents observed in the palps leads to greater efficiency in particle selection. The stomach of Castalia undosa undosa and most fresh- water bivalves is type IV (PURCHON, 1958). Some fresh- water bivalve genera such as Dreissena and Corbicula have a type V stomach (PURCHON, 1960). This uniformity of structures and ciliary currents can be seen in the studies conducted by GRAHAM (1949), PURCHON (1958), DINA- MANI (1967), HEBLING & PENTEADO (1974), HEBLING (1976), and VEITENHEIMER & MANSuUR (1978). According to HEBLING (1976), the anatomical unifor- mity of freshwater bivalves is due to convergent adaptation, Page 30 The Veliger, Vol. 34, No. 1 where by the different species have only a few points of difference and are practically identical in general terms. The three regions of the gut, with the typhlosole re- ducing the lumen and persisting throughout the length of the gut, are characteristics comparable to those detected in the Etheriidae by YONGE (1978), who considers this char- acteristic similar to that of the Unionidae studied by JEGLA & GREENBERG (1968). The configuration of the gut may possibly be a specific characteristic of the Hyriidae, as shown by MANSUR (1972, 1973), HEBLING & PENTEADO (1974) and the present study. More data, however, are needed to substantiate this statement. In Castalia undosa undosa, hermaphroditism is extremely rare and a clear sexual dimorphism occurs in the shell of the males; in males, the tip angle is smaller and the shell has a slight depression in the posteroventral region. Among the Hyriidae and Mycetopodidae studied, sexual dimor- phism occurs only in C. undosa undosa. ACKNOWLEDGMENTS Research supported by FAPESP (Fundagao de Amparo a Pesquisa do Estado de Sao Paulo), grant No. 86/2935- 8. We are grateful to Mr. M. S. Ribeiro for the drawings and to Mr. A. S. Costa for help with the field work. LITERATURE CITED ANSELL, A. D. 1961. The functional morphology of the British species of Veneracea (Eulamellibranchia). Journal of the Marine Biological Association of the United Kingdom 41: 489-515. ATKINS, D. 1937. On the ciliary mechanism and interrelation- ships of lamellibranchs. Part III. Types of lamellibranch gills and their food currents. Quarterly Journal of Micro- scopical Science 79:375-419. BoneTTo, A. A. 1961. Notas sobre los generos Castalina y Castalia en el Parana medio e inferior. Direction General de Recursos Naturales. Santa Fe, Argentina 6:3-11. BoneETTO, A. A. 1963. Contribucion al conocimiento de Leila blainvilleana (Lea) (Mollusca: Pelecypoda). Physis 24(67): 11-16, 3 figs. BoNETTO, A. A. 1965. Las almejas sudamericanas de la tribu Castaliini. Physis 25(69):187-196. DINAMANI, P. 1967. Variation in the stomach structure of the Bivalvia. Malacologia 5(2):225-268. GRAHAM, A. 1949. The molluscan stomach. Transactions of the Royal Society of Edinburgh 61(3):737-778. HEBLING, N. J. 1976. The functional morphology of Anodon- tites trapezeus and Anodontites trapesialis. Boletim de Zoolo- gia, Sao Paulo 1:265-298. HEBLING, N. J. & A. M. G. PENTEADO. 1974. Anatomia fun- cional de Diplodon rotundus gratus Wagner, 1827 (Mollusca, Bivalvia). Revista Brasileira de Biologia 34(1):67-80.- THERING, H. VON. 1891. Anodonta und Glabaris. Zoologischer Anzeiger 14(380/381):1-5. THERING, H. von. 1893. Najaden von S. Paulo und die geo- grafische verbreitung der Suesswasser-Faunen von Sued- merika. Archiv fur Naturgeschichte, ano 59, 1(1-3):45- & M. J. GREENBERG. 1968. Structure of the rectum. I. Morphology. The Veliger 10:253-263. KELLOGG, J. L. 1915. Ciliary mechanisms of lamellibranchs with descriptions of anatomy. Journal of Morphology 26(4): 625-701. LaNGE DE MorreTEs, F. 1949. Ensaio de catalogo dos mo- luscos do Brasil. Arquivos do Museu Paranaense, Curitiba 7(1):5-216. Mansur, M. C. D. 1972. Morfologia do sistema digestivo de Castalia undosa martensi (Ihering, 1891) (Bivalvia, Hyriidae). Iheringia Zoologia 41:21-34. Mansur, M. C.D. 1973. Morfologia do sistema digestivo das espécies do genero Diplodon spix, 1827 do rio Guaiba, Rio Grande do Sul (Unionacea—Hyriidae). Iheringia Zoologia 43:75-90. Mansur, M. C. D. & L. M. ANFLoR. 1981. Diferencas mor- fologicas entre Diplodon charruanus Orbigny, 1835 e D. pils- bry: Marshall, 1928 (Bivalvia, Hyriidae). Iheringia Zoologia 60:101-116. Mansur, M.C. D. & I. L. VEITENHEIMER. 1975. Nova espécie de Eupera (Bivalvia: Sphaeriidae) e primeiros estudos ana- tomicos dentro do genero. Iheringia Zoologia 47:23-46. Morton, B.S. 1978. The biology and functional morphology of Claudiconcha japonica (Bivalvia: Veneracea). Journal of Zoology, London 184:35-52. NarcHI, W. 1971. Structure and adaptation in 77ansennella tantilla (Gould) and Gemma gemma (Totten). 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South American naiades, a contribution to the knowledge of the fresh-water mussels of South Amer- ica. Memoirs of the Carnegie Museum 8(3):451-670. OweEN, G. 1953. On the biology of Glossus humanus (L.) Iso- cardia cor Lam. Journal of the Marine Biological Associa- tion of the United Kingdom 32:85-106. PuRCHON, R. D. 1958. The stomach in the Eulamellibranchia; stomach type IV. Proceedings of the Zoological Society of London 131(4):487-525. PurcHon, R. D. 1960. The stomach in the Eulamellibranchia; stomach types IV and V. Proceedings of the Zoological So- ciety of London 135(3):431-438. TayLor, J. D., W. J. KENNEDY & A. HALL. 1969. The shell structure and mineralogy of the Bivalvia. Introduction. Nu- culacea Trigonacea. Bulletin of the British Museum (Nat- ural History), (Zool.), Supplement 3:1-125. VEITENHEIMER, I. L. & M. C. D. Mansur. 1978. Morfologia, histologia e ecologia de Mycetopoda legumen (Martens, 1888)—Bivalvia, Mycetopodidae. Iheringia Zoologia 52:33- TAB WuiteE, K. M. 1942. Pericardial cavity and the pericardial gland of the Lamellibranchia. Proceedings of the Malaco- logical Society of London 25:37-88. W. E. P. Avelar & S. C. D. Santos, 1991 YONGE, C. M. 1949. On the structure and adaptation of the Tellinacea, deposit fedding. Eulamellibranchia. Philosoph- ical Transactions of the Royal Society of London 234:29- 76. YONGE, C. M. 1957. Mantle fusion in the Lamellibranchia. Page 31 Pubblicazioni della Stazione Zoologica di Napoli 29:151- 171, 11 figs. YONGE, C. M. 1978. On the monomyarian Acostaea rivoli and evolution in the family Etheriidae (Bivalvia: Unionacea). Journal of Zoology, London 184:429-448. The Veliger 34(1):32-37 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 Commensals Associated with Xenophora (Onustus) longley: Bartsch (Mollusca: Gastropoda) in the Gulf of Mexico and Caribbean Sea JOHN WHORFF Department of Biology, Texas A&M University, College Station, Texas 77843-3258, USA Abstract. Forty-seven specimens of Xenophora (Onustus) longleyi from 11 locations in the Gulf of Mexico and Caribbean Sea were examined for commensals. Commensal type and frequency are described among five size classes of X. longleyi. In addition, egg cases containing well-developed larvae are described, and may be the first reported for any species within the Xenophoridae. INTRODUCTION Xenophora (Onustus) longleyi Bartsch, 1931, is a relatively common deep-water mesogastropod occurring in soft sed- iments in the western Atlantic (PONDER, 1983). One of the largest in the family Xenophoridae, this species is known to have many commensals, including tube-building polychaete worms and Epizoanthus (TAKEDA & OKUTANI, 1983). However, no study, descriptive or otherwise, has been undertaken on the relationship between X. longleyi and its commensals. The biology of the deep-water Xenophoridae is poorly known, although some work has been done on a few of the shallow-water species (CROZIER, 1919; MorTon, 1958; SHANK, 1969; BERG, 1975). Gut content analysis suggest they are detritivores, although Xenophora (Onustus) exuta was found to feed selectively on foraminiferans (PONDER, 1983). Their general life history suggests they are well adapted to eluding detection by predators (ST. JEAN, 1977). The exterior of the shell is usually well camouflaged with attached debris, although deeper-water species living on soft, uniform bottoms are thought to have little attached material since visual predation is no longer relevant (PONDER, 1983). Xenophora longleyi is known to have commensals living on the exterior, on the base, and within the umbilicus (TAKEDA & OKUTANI, 1983). The purpose of this paper is to descri ihe types of commensals and determine whether the1 1 relationship between shell size and commensal frequency on 47 specimens of X. longley: from 11 stations in the Gulf of Mexico and Caribbean Sea. MATERIALS anD METHODS Twenty-six specimens of Xenophora longley: were obtained from a survey on the fishery potential of the megalops shrimp, Penaeopsis serrata, from six stations in the north and northwestern Gulf of Mexico (Figure 1). All of these stations were characterized by soft sediments with depths ranging from 311 to 704 m. All specimens from this fishery project have been deposited at the California Academy of Science, San Francisco. The remaining 21 specimens were examined from the Texas A&M Oceanography Collection (TAMOC 4-0389, 4-1224, 4-1755, 4-1756, 4-1757) col- lected from stations located in the southwestern Gulf of Mexico and Caribbean Sea in depths ranging from 457 to 823 m (Figure 1). Shell height was measured from the apex to the lower margin of the aperture of each shell. Basal diameter was recorded as the greatest distance between the sutures along the shell base. The relationship of shell height to basal diameter was examined using linear regression. The basal diameter was used as the most consistent measure of shell size, since the apex of some of the larger specimens was eroded. The number and type of commen- sals were recorded for each specimen, and frequencies of these values were established by partitioning the basal diameter values into discrete size classes (2.0-2.9 cm, 3.0- J. Whorff, 1991 BASAL DIAMETER (cm) Basal diameter versus shell height in 47 specimens of Xenophora (Onustus) longleyi. These two parameters show a strong positive Page 33 Da A Gulf of Mexico 3 pub Ee os Nee a 500 km Figure 1 Eleven locations where 47 specimens of Xenophora (Onustus) longley: were obtained. CORRELATION COEFICIENT=9720 n=47 CORRELATION COEFFICIENT=0.9898 n=5 € 2 c WW = WwW = = a 4 6.0 cm. J. Whorff, 1991 Explanation of Figures 5 to 7 Figure 5. An egg case found just outside the aperture of Xenophora (Onustus) longley:. A. Egg case. B. Magnified view of egg case membrane. Figure 6. Developing larvae from the egg case in Figure 5. A and B. Two different views. Key: n, embryonic shell nodule; m, embryonic membrane. Figure 7. Protoconch of a juvenile specimen of Xenophora (Onustus) longley:. A. Calcareous nodules observed along the suture line of the protoconch of the same size and shape as nodules from the embryonic shell shown in Figure 6. B- Slightly eroded protoconch. Key: ns, suture nodule. Page 36 The Veliger, Vol. 34, No. 1 3.9 cm, 4.0-4.9 cm, 5.0-5.9 cm, >6.0 cm). Shell size classes and commensal frequencies were related using linear re- gression analysis of basal diameter versus commensal fre- quency. Observations of some egg cases containing larvae, and of the protoconch of a juvenile Xenophora longley: were made using SEM techniques. RESULTS Basal diameter ranged from 2.2 to 8.6 cm, and shell height ranged from 1.7 to 6.1 cm. Basal diameter was strongly correlated with shell height (Student’s t-tests of r # 0; P < 0.0001). The slope was 1.2769 with a variance of 2.1 x 10-3 (Figure 2). The numbers and types of commensals found on the specimens are summarized in Table 1, and included rep- resentatives from the phyla Cnidaria (sea anemones and zoanthids), Annelida (polychaete worms), and Arthropoda (barnacles). The five shell size classes did not correlate with the total commensal frequency (Student’s ¢-test of r + 0; P < 0.1). The slope was 5.56 with a variance of 2.93 (Figure 3). A more descriptive frequency distribution shows the proportion of specimens with commensals within each of the size classes (Figure 4). Fourteen gastropod egg cases containing shelled larvae were found on the shell base near the aperture of one specimen from the northwestern Gulf of Mexico taken during the month of June (Figures 5, 6). Twenty-two other egg cases were found on the exterior of eight specimens taken from three out of the four Caribbean locations during the month of July. These 22 egg cases could not be iden- tified, but all were identical and appeared to have a single large trochophore larva surrounded by light colored yolk material. DISCUSSION The eunicid polychaetes are usually restricted to hard sub- strates, and are commonly carnivores, although some scav- engers and detritivores are known (FAUCHALD, 1977). The eunicids found living on Xenophora longley: build tough parchment-like tubes within the umbilicus of this species. The single scale worm observed could not be identified beyond the family Polynoidae because all but one of the elytra were missing. However, scale worms are typically common in deep-water areas (LEVENSTEIN, 1984). All of these commensals are likely to benefit when food is stirred or uncovered from the sediment by foraging or locomotor activity of X. longley:. Although the sediment may be dis- turbed within the confines of the wide peripheral flange when the animal is foraging from its retracted position, most of the disturbance probably occurs when the animal exhibits its peculiar hopping motion during the locomotion described by PONDER (1983). ‘lard substrate is a scarce resource for deep-sea sessile ‘brates along the deep-water continental shelf where Table 1 The types and numbers of commensals found on 47 spec- imens of Xenophora (Onustus) longleyi. Number of | Number of commensals xX. longleyi Phylum Cnidaria Epizoanthus sp. 8 8 Actinaria sp. 9 5 Phylum Annelida Eunice aphoditors 12 12 Eunice (other) 3 3 Polynoidae sp. 1 1 Phylum Arthropoda Verruca floridiana 9 Acroscalpellum intonsum 3 1 Totals 45 22; Xenophora longleyi was found in this study (HOLLAND et al. 1980). As a result, this species provides attachment space for larvae that might otherwise have little chance for survival. Some of the commensals also derive protection from the shell. Polychaetes are well protected by living in the umbilicus of the shell, while zoanthids are well pro- tected where they attach along the base of the shell within the confines of the wide peripheral flange. No strong correlation could be found between shell size classes and commensal frequency, primarily because the sample size was too low to generate a more accurate fre- quency distribution with a greater number of size classes. Clearly, however, commensals are absent or in lower pro- portion in smaller specimens (Figure 4). The shell of Xenophora longley: provides, in addition to a hard substrate for commensals, hard substrate on which invertebrates can lay eggs. The eggs found on the exterior of the Caribbean shells were all the same. This is not surprising since the eggs were found on specimens from the same general region at the same time of year. The molluscan egg cases (Figure 5) found on the specimen from the Gulf of Mexico may be of more significance. There are no known records of the spawn or larvae for any Xenophora species (PONDER, 1983). However, these egg cases could possibly have been laid by X. longley:. It is unlikely that another mollusk would intrude to within the protective boundary of the peripheral flange near the ap- erture unless it was a predator. The egg cases were laid just outside the aperture. Each of the larvae within the egg cases was enclosed in a thin membrane and had a shell closely resembling the beginning of the protoconch shown for X. longley: (Figures 6, 7). The calcareous nodules that constitute the embryonic shell were observed to be the same size and shape as those observed along the suture line of the protoconch of X. longleyi. J. Whorff, 1991 ACKNOWLEDGMENTS I thank Gretchen Jones for doing the electron microscopy work, Rezneat Darnell for providing access to the Texas A&M Oceanography Collections, Joe Goy for reviewing the manuscript, and Fain Hubbard and Chris Pomory for helping to identify commensal specimens. Also, I wish to thank Mary Wicksten for providing me with specimens from her survey on the fishery potential of the shrimp Penaeopsis in the Gulf of Mexico, and for reviewing this manuscript. LITERATURE CITED BERG, C. J. 1975. Behaviour and ecology of conch (superfamily Strombacea) on a deep subtidal algal plain. Bulletin of Ma- rine Science 25:307-317. Crozier, W. J. 1919. On the use of the foot in some mollusks. Journal of Experimental Zoology 27:359-366. FAUCHALD, K. 1977. The polychaete worms. Natural History Museum of Los Angeles County, Science Series 28:1-190. HOLLAND, J. S., J. HOLT, R. KALKE & N. N. Rasatats. 1980. Benthic invertebrates: macrofauna and epifauna. Pp. 515- Page 37 590. In:R. W. Flint & N. N. Rabalais (eds.), Environmental Studies, South Texas Outer Continental Shelf, 1975-1977. Vol. III. Study Area Final Report. University of Texas Marine Science Institute, Port Aransas. LEVENSTEIN, R. Y. 1984. On the ways of formation of the deep sea polychaete fauna of the family Polynoidae. Pp. 72-85. In: P.A. Hutchings (ed.), Proceedings of the First Interna- tional Polychaete Conference, Sydney. The Linnean Society of New South Wales. Morton, J. E. 1958. The adaptations and relationships of the Xenophoridae (Mesogastropoda). Proceedings of the Mal- acological Society of London 33:89-101. PONDER, W. F. 1983. A revision of the recent Xenophoridae of the world and of the Australian fossil species (Mollusca: Gastropoda). The Australian Museum (Sydney). Memoir 17:1-122. ST. JEAN, K. 1977. The Xenophoridae—how and why they collect: some new insights. The Annual Report of the West- ern Society of Malacologists (1977):11. SHANK, P. 1969. The timorous carrier shell; close observations of Xenophora conchyliophora Born. New York Shell Club Notes 151:5-7. TAKEDA, M. & T. OKUTANI. 1983. Crustaceans and Mollusks Trawled off Suriname and French Guiana, pp. 246-247. Japan Marine Fishery Resource Research Center, Tokyo. The Veliger 34(1):38-47 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 Four New Pseudococculinid Limpets Collected by the Deep-Submersible Alvin in the Eastern Pacific by JAMES H. McLEAN Los Angeles County Museum of Natural History, 900 Exposition Boulevard, Los Angeles, California 90007, USA Abstract. Four new species of Pseudococculinidae collected with the deep-submersible Alvin are described. One species represents a new monotypic genus, Punctabyssia, and two represent new sub- genera: Dictyabyssia (of Caymanabyssia Moskalev, 1976) and Gordabyssia (of Amphiplica Haszprunar 1988). New species are: Punctabyssia tibbettsi and Caymanabyssia (Dictyabyssia) fosteri, both from the same piece of wood at abyssal depths on the East Pacific Rise Axis near 12°N, and two from abyssal depths on the Gorda Ridge off northern California, Caymanabyssia (Caymanabyssia) vandoverae and Amphiplica (Gordabyssia) gordensis. The latter is the first member of the family to be recovered from sulfide crust in the hydrothermal-vent habitat. New character states for the radula and protoconch are defined for the new genus Punctabyssia. INTRODUCTION The cocculiniform limpets include a number of deep-sea families in which there is an association with biogenic substrates (for review see HASZPRUNAR, 1988b). Until re- cently the only method by which these limpets have been recovered has been by chance trawling of pieces of wood or other biogenic substrates. Records of cocculiniform lim- pets are so infrequently obtained that many species remain known from a single station. Such a sparsity of records indicates that our knowledge of the distribution of these species is very incomplete and that additional new species are likely to be discovered. A more direct approach to sampling the widely scattered wood or bone “islands” (TURNER, 1978) is now possible with the deployment of deep-submersible research sub- marines. The four pseudococculinid limpets described here were collected by using the deep-submersible Alvin of the Woods Hole Oceanographic Institution. Although the ob- jective of each dive was the exploration of hydrothermal- vent fields, three of the four species were taken on wood outside the influence of hydrothermal activity. Two species were found on the same piece of wood recovered from the ridge axis of the East Pacific Rise near 12°N. One represents a monotypic new genus, and the other a new subgenus, which has a congener from abyssal depths near New Zealand. I pecies are added from explorations of the Alvin e Gorda Ridge, one from wood not under the influence of hydrothermal vents, and another from sulfide crust pro- duced by hydrothermal vents. The latter species represents a new monotypic subgenus and is the first member of the family restricted to the hydrothermal-vent habitat. Recent work on the systematics and anatomy of the pseudococculinid limpets (MOSKALEV, 1976; HICKMAN, 1983; MARSHALL, 1986; HASZPRUNAR, 1988a; MCLEAN, 1988) makes it possible to establish the taxonomic place- ment of the four new species treated here, and to justify the proposal of new generic and subgeneric taxa. The new species described here introduce new character states for the family Pseudococculinidae and contribute to the understanding of relationships of genera within the family. The broader implications for classification are summarized in the discussion. MATERIALS anp METHODS Limpet specimens were collected on wood or other sub- strate samples with the mechanical arm of the deep-sub- mersible Alvin. Material was preserved on reaching the surface, fixed in buffered formalin, and transferred to 70% alcohol. Sorting was accomplished at Woods Hole Ocean- ographic Institution, following which the specimens were forwarded to me. Radulae were extracted from preserved specimens after dissolution of tissues in 10% NaOH, washed in water, air dried, and coated with gold or gold-palladium for exam- ination with SEM. Protoconchs and juvenile shells were J. H. McLean, 1991 examined with SEM. Protoconch lengths were taken di- rectly from scale indications for the SEM micrographs. Institutions mentioned in the text are abbreviated as follows: LACM, Los Angeles County Museum of Natural History; USNM, National Museum of Natural History, Washington, D.C. Suborder Cocculiniformia Haszprunar, 1987 Superfamily LEPETETELLACEA Dall, 1881 Family PSEUDOCOCCULINIDAE Hickman, 1983 Punctabyssia McLean, gen. nov. Type species: P. tibbettsi McLean, sp. nov. Diagnosis: Shell thin and translucent; protoconch with tightly spaced pits in longitudinal rows; teleoconch sculp- ture of fine concentric ridges with larger pits in interspaces. Eyes lacking, right cephalic tentacle slightly larger than left; gill leaflets present on right side only; epipodial ten- tacles a single posterior pair. Rachidian tooth large and quadrangular, uncusped; cusp of first lateral with fine serrations; upper shaft and cusp of second lateral fused with that of first lateral; third and fourth laterals with long beaklike cusps; fifth lateral reduced to stubby base; marginals similar in size. Remarks: The protoconch sculpture of Punctabyssia is unique in having pits in rows. Punctabyssia is also unique in the serration on the first lateral and in the fusion between the cusps of the first and second laterals. Punctations on the protoconch are otherwise known only in Tentaoculus Moskalev, 1976. As diagnosed by MARSHALL (1986), Ten- taoculus differs in having the protoconch pits in irregular order, in having a tapered, cusped rachidian, a strongly developed fifth lateral, having eyes, and occurring at bathy- al rather than abyssal depths. Etymology: The name derives from the Latin noun punc- tura, hole, with reference to the punctate sculpture of both protoconch and teleoconch, combined with the word-end- ing first used by MOSKALEV (1976) for genera related to Pseudococculina. Punctabyssia tibbettsi McLean, sp. nov. (Figures 1-8) Description: Shell (Figures 1-3, 6) of medium size for family (maximum length 5.0 mm), translucent; periostra- cum thin, smooth. Height low, that of holotype 0.26 times that of length. All slopes nearly straight. Outline in dorsal view elongate-oval, anterior end slightly broader than pos- terior; sides of shell slightly raised relative to ends. Apex slightly anterior to center, at highest point of shell. Shell of most specimens with scattered, shallow eroded areas. Protoconch (Figure 6) lost in all but small specimens under 2 mm in length; protoconch posteriorly directed, length 170 um, sculpture of fine pits aligned in rows. Teleoconch Page 39 sculpture of fine concentric ridges, ridges sometimes co- alescing; interspaces with aligned rows of pits (Figure 6); pits larger than those of protoconch, present at all stages of growth. Radial sculpture lacking. Shell margin sharp, easily chipped; interior transparent, showing exterior pat- tern of erosion; position of muscle scar not visible in shell interior. Dimensions: Length 4.7, width 3.5, height 1.2 mm (ho- lotype). External anatomy (Figures 4, 5) as described for genus. Radula (Figures 7, 8): Shaft of rachidian tooth broad, laterally constricted near base, upper edge with thick swell- ing, uncusped. First and second lateral fused at midshaft and having fused cusps. First lateral large, extending well above position of rachidian, its cusp with fine serrations on inner side and beaklike cusp at tip, which derives from second lateral. Fused second lateral with strong lateral projection. Third and fourth laterals with lateral curvature and long beaklike cusps. Fifth lateral reduced to shaft base only. Marginals numerous, with pointed cusps and ser- rations, similar in size. Type locality: Along axis of East Pacific Rise near 12°N (11°51'N, 103°50’'W), on wood, 2700 m. Type material: 14 specimens from type locality, collected with deep-submersible Alvin, dive No. 2000, 22 March 1988. Holotype LACM 2434, 7 paratypes LACM 2435, 6 paratypes USNM 784764. Remarks: Although only 2 of the 14 specimens retained the protoconch, the specimens of this species are otherwise in good condition, not showing the nearly complete erosion of the shell that is often characteristic of pseudococculinid as well as cocculinid species. The gill leaflets are so small that they can readily be seen only on one of the paratype specimens; unfortunately they are not apparent in Fig- ure 5. Etymology: The specific name honors Paul Tibbetts, one of the pilots of Alvin, marking Alvin dive 2000, a major peak in the history of undersea exploration. Caymanabyssia Moskalev, 1976 Type species: C. spina Moskalev, 1976. Diagnosis: Shell sculpture dominated by pustules super- imposed on anastomosing network of surface sculpture; protoconch microsculpture of columnar crystals. Eyes lack- ing, oral lappets present, several gill leaflets present on right side; single leaflet on left; right cephalic tentacle of same size or slightly larger than left; epipodial tentacles a single posterior pair. Radula degenerate, rachidian and laterals lacking cusps. Remarks: MARSHALL (1986) allowed a species in Cay- manabyssia that lacked the conical granules that dominate the teleoconch sculpture of the type species of the genus. The discovery of another species with the same lack of a Explanation of Figures 1 to 8 Figures 1-8. Punctabyssia tibbettsi McLean, sp. nov. Alvin dive 2000, near 12°N, 2700 m. Anterior at top in vertical views. Figures 1-3. Holotype, LACM 2434. Exterior, interior, and left lateral views. Length 4.7 mm. Figure 4. Dorsal view of holotype body, showing contracted right cephalic tentacle larger than left through mantle skirt. Length 3.0 mm. Figure 5. Ventral view of holotype body, showing posterior pair of epipodial tentacles at right; gill leaflets obscured by foot. Length 3.0 mm. Figure 6. SEM view of protoconch and early teleoconch, oblique view from left side, showing pits on protoconch and teleoconch. Scale bar = 40 um. Figure 7. SEM view of half- rows of radular ribbon. Scale bar = 10 wm. Figure 8. SEM view of nearly full width of radular ribbon. Scale bar = 20 um. jena Mckecant 199i major sculptural element warrants the separation of the two species at least at the subgeneric level. Accordingly the subgenus Dictyabyssia is described below. Dictyabyssia McLean, subgen. nov. (of Caymanabyssia Moskalev, 1976) Type species: Caymanabyssia sinespina Marshall, 1986. Diagnosis: Surface sculpture of anastomosing threads; lacking conical granules. Protoconch (where known) sculp- tured with minute columnar crystals. External anatomy and radula as in typical subgenus. Remarks: The need for this subgenus is noted above. Mar- shall’s species is selected as the type species of the new subgenus because it has an intact protoconch, which is missing on specimens of the species described here. Two species are known in Dictyabyssia, the type species and the following new species. Etymology: The name combines the Greek noun dictyon, meaning net, with reference to the anastomosing sculpture, plus the word-ending first used by MOSKALEV (1976) for genera related to Pseudococculina. Caymanabyssia (Dictyabyssia) fostert McLean, sp. nov. (Figures 9-16) Description: Shell (Figures 9-11, 14, 15) of medium size for family (maximum length 5.7 mm), translucent white, periostracum very thin. Height moderate, that of holotype 0.46 times that of length. All slopes weakly concave. Out- line in dorsal view elongate-oval, anterior narrower than posterior; margin of aperture nearly resting in same plane. Apex at % shell length from anterior end, at highest point of shell. Protoconch unknown; apical area eroded in all specimens (none smaller than 2.5 mm). Teleoconch sculp- ture preserved at margin of smallest specimens, consisting of concentric growth irregularities and fine, densely anas- tomosing surficial threads (Figures 14, 15) visible under high magnification. Radial sculpture lacking. Entire sur- face of all specimens over 4 mm in length deeply eroded, showing coalescing linear pattern typical in family (Figure 9). Position of muscle scar marked by thick callus deposits in dorsal view (Figure 9), showing the inward expansion of scar characteristic of family. Shell margin sharp, easily chipped. Interior glossy white, outline of muscle scar well marked in mature specimens, anterior pallial attachment scar also marked. Shell interior thickened within to com- pensate for exterior erosion. Dimensions: Length 5.7, width 4.2, height 2.6 mm (ho- lotype). Eternal anatomy (Figures 12, 13) as defined for genus. Radula (Figure 16): Rachidian tooth quadrangular, outer edges thickened, upper edge thin, uncusped. First lateral tooth elongate and tilted, cusp rows of laterals higher than Page 41 that of rachidian. First four laterals with projecting nubs but no overhanging cusps. Fifth lateral reduced to stubby basal portion. Marginal teeth of similar size, with long, beaklike cusps. Type locality: Along axis of East Pacific Rise near 12°N (11°51’N, 103°50’W), on wood from 2700 m. Type material: 19 specimens from type locality, collected with deep-submersible Alvin, dive No. 2000, 22 March 1988. Holotype LACM 2436, 10 paratypes LACM 2437, 8 paratypes USNM 784765. Remarks: Caymanabyssia (Dictyabyssia) fosteri reaches a much larger size than C. (D.) sinespina Marshall, 1986, from New Zealand (5.8 mm, compared to 2.15 mm). In addition, the anastomosing sculpture of the immature spec- imen of C. (D.) fosteri (Figure 15) is much more dense than that illustrated by Marshall for C. (D.) sinespina. Radulae of all species of Caymanabyssia s.s. and C. (Dic- tyabyssia) are similar, characterized by MARSHALL (1986) as “degenerate” in lacking cusps on the rachidian and laterals. Etymology: The specific name honors Dudley Foster, se- nior pilot of the Alvin, on the occasion of the hallmark Alvin dive 2000. Caymanabyssia (Caymanabyssia) vandoverae McLean, sp. nov. (Figures 17-24) Description: Shell (Figures 17, 18, 22-24) of small size for family but typical size for genus (maximum length 3.9 mm), translucent white, periostracum very thin. Height low, that of holotype 0.25 times that of length. All slopes slightly convex. Outline in dorsal view elongate-oval, an- terior end same width as posterior; sides of shell raised relative to ends. Apex nearly central, at highest point of shell. Protoconch (Figures 22-24) posteriorly directed, length 200 wm, sculpture of clumped columnar prisms, usually lost in specimens over 3.0 mm in length. Teleo- conch sculpture of prominent pustules aligned in curving rows, superimposed on microsculpture of finely anasto- mosing threads; threads visible only under high magnifi- cation. Radial sculpture lacking. Sculpture preserved in large specimens, although scattered erosional pits are pres- ent. Interior surface translucent white, revealing position of exterior erosional pits and only faintly indicating po- sition of muscle scar. Shell edge showing position of ex- terior pustules. Dimensions: Length 3.6, width 2.7, height 0.9 mm (ho- lotype). External anatomy (Figures 19, 20) as defined for genus. Radula (Figure 21): Rachidian plate broad, thin, raised at edges, lacking overhanging cusp. First lateral tooth ex- tending to height of rachidian, with strong lateral projec- tion, lacking cusp. Second, third, and fourth laterals with Page 42 The Veliger, Vol. 34, No. 1 Explanation of Figures 9 to 16 Figures 9-16. Caymanabyssia (Dictyabyssia) fosteri McLean, sp. nov. Alvin dive 2000, near 12°N, 2700 m. Anterior at top in vertical views. Figures 9-11. Holotype, LACM 2436. Exterior, interior, and left lateral views (surface sculpture eroded). Length 5.7 mm. Figure 12. Ventral view of paratype body attached to shell, showing paired posterior epipodial tentacles. Length 5.6 mm. Figure 13. Dorsal view of same specimen detached from shell, showing cephalic tentacles of nearly equal size. Length 3.0 mm. Figure 14. SEM view of juvenile shell with intact surface sculpture, but eroded protoconch. Scale bar = 1 mm. Figure 15. SEM view of surface detail of anastomosing lines in same specimen as in Figure 14, eroded apical area at right. Scale bar = 200 um. Figure 16. SEM view of radular ribbon. Scale bar = 40 um. Explanation of Figures 17 to 24 Figures 17-24. Caymanabyssia (Caymanabyssia) vandoverae McLean, sp. nov. Alvin dive 2034, Gorda Ridge, 3362 m. Anterior at top in vertical views. Figures 17, 18. Holotype, LACM 2438. Exterior and interior views. Length 3.9 mm. Figures 19, 20. Dorsal and ventral views of detached body of holotype, showing right cephalic tentacle slightly larger than left. Length 2.2 mm. Figure 21. SEM view of radular ribbon. Scale bar = 40 wm. Figure 22. SEM view of protoconch and teleoconch surface, showing pustules and anastomosing sculpture of teleoconch. Scale bar = 100 wm. Figure 23. Detail of protoconch sculpture, showing columnar prisms. Scale bar = 60 um. Figure 24. Enlargement of columnar prisms in area outlined by rectangle of Figure 23. Scale bar = 15 um. Page 44 lateral elbows, lacking cusps. Fifth lateral elongate, with two basal prongs to shaft, cusps lacking. Marginal teeth numerous, long and slender, with sharp cusp and serra- tions, nearly equal in size. Type locality: Escanaba Trough, Gorda Ridge (41°00.4'N, 127°29.3'W), on wood, 3362 m. Type material: 5 specimens from type locality, collected with deep-submersible Alvin, dive No. 2034, 4 June 1988. Holotype LACM 2438, 4 paratypes LACM 24339, 1 para- type USNM 784766. Remarks: Caymanabyssia vandoverae is clearly a member of subgenus Caymanabyssia in having the sculpture dom- inated by pustules superimposed on an anastomosing net- work of surface sculpture, having the protoconch micro- sculpture of columnar crystals, and having a radula lacking cusps on the rachidian and laterals. The dorsal sperm groove is prominent and may be seen by probing the ten- tacle in ventral view. The new species is the third member of the genus. Other species are the type species from the Cayman Trough in the Western Atlantic, and C. rhina Marshall, 1986, from off White Island, New Zealand. It differs from C. rhina in having much more prominent and densely spaced pustules. Moskalev’s C. spina also has more broadly spaced pustules than C. vandoverae. Etymology: The name honors Dr. Cindy Van Dover, of Woods Hole Oceanographic Institution, who is responsible for the preservation and forwarding of each species de- scribed herein. Amphiplica Haszprunar, 1988 Type species: A. venezuelensis McLean, 1988. Diagnosis: Shell size large for family; white, periostracum thin; protoconch unknown; teleoconch sculpture of sharply raised concentric ridges. Eyes lacking, right tentacle similar in size to left; up to six pairs of secondary subpallial gill leaflets on both sides near anterior end of foot; oral lappets present; epipodial tentacles a single posterior pair. Ra- chidian tooth prominent, tapered, with beaklike cusp; lat- eral teeth with sharply pointed cusps; fifth lateral with five short denticles; innermost marginals larger than the rest. Remarks: The new species described below has the sharply raised concentric sculpture, the secondary gill lamellae on both sides, and the oral lappets (although more weakly developed) of Amphiplica, but differs in its smaller size, having a more posterior apex, retaining the protoconch in mature sizes, and radular differences (four strong rather than five weak cusps on the fifth lateral, the second mar- ginal tooth not larger than the others). The three members of Amphiplica s.s. (A. venezuelensis McLean, 1988, A. knudseni McLean, 1988, and A. concentrica (Thiele, 1909)) e the largest known members of the family. These three ies lose the protoconch at an early age. The Veliger, Vol. 34, No. 1 These differences are recognized at the subgeneric level. Gordabyssia McLean, subgen. nov. (of Amphiplica Haszprunar, 1988) Type species: Amphiplica (Gordabyssia) gordensis McLean, sp. nov. Diagnosis: Shell small, white, periostracum thin; proto- conch with subreticulate pattern of anastomosing threads in longitudinal rows; teleoconch sculpture of sharply raised concentric ridges. Eyes lacking, right tentacle similar in size to left; up to six pairs of secondary subpallial gill leaflets on both sides near anterior end of foot; epipodial tentacles a single posterior pair. Rachidian tooth promi- nent, tapered, cusp beaklike; lateral teeth with sharply pointed cusps; fifth lateral with four pointed cusps; in- nermost marginals larger than the rest. Remarks: Reasons to justify the new subgenus are given above. The new species described here provides a provi- sional protoconch definition for the genus Amphiplica s.s., as the protoconch is unknown in the typical subgenus. Should the protoconch in the typical subgenus prove to be of a different type, the subgenus Gordabyssia should be raised to a full genus. Similar protoconch sculpture to that of Amphiplica (Gordabyssia) gordensis is known in Me- sopelex Marshall, 1986, and Kurilabyssia Moskalev, 1976, but characters of radula and teleoconch sculpture do not agree. The new species is the only member of the family to be associated with sulfide crust at hydrothermal vents, albeit having a very limited distribution in the habitat. Specimens were collected from four stations in the Escanaba Trough on the Gorda Ridge, in each case on hard substrates, in- dicated as sulfide crust on the labels, so it is clear that this is not an association with wood, as in most other pseu- dococculinids. There seem to be no modifications that cor- relate with the hydrothermal-vent environment. Amphiplica (Gordabyssia) gordensis McLean, sp. Noy. (Figures 25-32) Description: Shell (Figures 25-27, 29, 30) of medium size for family (maximum length 3.9 mm), translucent; peri- ostracum thin, light brown. Height low, that of holotype 0.28 times that of length. Anterior and lateral slopes con- vex; posterior slope straight. Outline in dorsal view elon- gate-oval, anterior end about the same width; shell margin in same plane (sides or ends not raised). Apex posterior to center, at highest point of shell. Shell of most specimens with scattered, shallow eroded areas. Protoconch (Figures 29, 30) retained on most specimens, even on specimens with eroded apical area; protoconch posteriorly directed, length 200 um, sculpture of subreticulate pattern of anas- tomosing threads in longitudinal rows. Teleoconch sculp- Explanation of Figures 25 to 32 Figures 25-32. Amphiplica (Gordabyssia) gordensis McLean, sp. nov. Alvin dive 2035, Gorda Ridge, 3305 m. Anterior at top in vertical views. Figures 25, 26. Holotype, LACM 2440. Exterior and interior views. Length 3.9 mm. Figure 27. Ventral view of holotype body attached to shell, showing paired gill leaflets near both sides of foot. Length 3.9 mm. Figure 28. Dorsal view of detached body of holotype. Length 2.1 mm. Figure 29. SEM view of protoconch (with subreticulate sculpture) and teleoconch surface (concentric sculpture). Scale bar = 100 um. Figure 30. Enlarged view of subreticulate sculpture of protoconch. Scale bar = 25 wm. Figure 31. SEM view of radular ribbon. Scale bar = 25 wm. Figure 32. Enlarged view of central field, showing four cusps on fifth lateral tooth. Scale bar = 12 um. Page 46 ture of fine, sharp concentric ridges, ridges not coalescing. Radial sculpture of exceedingly fine striae, detectable un- der high magnification, producing fine swellings on cross- ing concentric ridges. Shell margin sharp, easily chipped; interior transparent, showing exterior pattern of erosion; position of muscle scar faintly visible in shell interior. Dimensions: Length 3.9 mm, width 2.8 mm, height 1.1 mm (holotype). External anatomy (Figures 27, 28) as described for ge- nus and subgenus. Radula (Figures 31, 32): Rachidian tooth elongate, ris- ing above level of all lateral teeth, having simple beaklike overhanging cusp, central part of shaft laterally expanded. First pair of laterals with strong lateral projection, over- hanging cusp with long tip and serrations on inner side; second, third, and fourth laterals similarly shaped, cusps with single pointed tip and serrations on both sides. Fifth lateral tooth massive, with four pointed cusps; marginal teeth with long overhanging cusps, the second, third, four and fifth pairs having the longest cusps. Type locality: Escanaba Trough, Gorda Ridge (41°00.4'N, 127°29.3'W), on sulfide crust, 3305 m. Type material: 34 specimens from type locality, collected with deep-submersible Alvin, dive No. 2035, 5 June 1988. Holotype LACM 2440, 18 paratypes LACM 2441, 15 paratypes USNM 784767. Additional paratypes were taken at four other Alvin dives at the type locality (same coordinates for each dive but different depths and dates): LACM 2441a, 5 speci- mens, dive 2033, 3356 m, 3 June 1988; LACM 2441b, 4 specimens, dive 2039, 3305 m, 9 June 1988; LACM 244 1c, 9 specimens, dive 2040, 3271 m, 10 June 1988; LACM 2441d, 1 specimen, dive 2042, 3271 m, 12 June 1988. Remarks: This species exhibits considerable variation in shell proportions and in the degree of erosion. A number of specimens were smaller, more elevated and with more compressed sides than the holotype. Most specimens retain the protoconch, even though the surface sculpture on the anterior slope may be eroded. One other limpet has recently been described from the Escanaba Trough on the Gorda Ridge: Neoleptopsis gor- densis McLean, 1990. A general report on the hydrother- mal-vent fauna of the Escanaba Trough on the Gorda Ridge is given by VAN Dover et al. (1990). Etymology: The specific name derives from the type lo- cality, the Gorda Ridge. DISCUSSION Until now the family Pseudococculinidae has been rep- resented in the Eastern Pacific by a single species, Ya- quinabyssia carey: McLean, 1988, from the Cascadia Abys- sal Plain off Oregon. The four species described here bring the total to five species for the family in the Eastern Pacific. The Veliger, Vol. 34, No. 1 The use of a deep-submersible research submarine has provided new opportunities to locate and sample “islands” of biogenic origin, a sparse habitat in the deep sea (TURNER, 1978). Further opportunities should be taken whenever possible to sample additional wood falls on dives made by deep-submersibles. The sparsity of records indicates that our knowledge of distribution is minimal and that addi- tional species of Pseudococculinidae may remain to be discovered. New limits to character states in the family Pseudococ- culinidae are provided here by the new monotypic genus Punctabyssia, which has a unique protoconch with pits aligned in rows and radular tooth elements that show a derived state of fusion between the first and second lateral tooth elements, which in all other genera are separate elements. The new subgenus Dictyabyssia (of Caymanabyssia) flags the existence of two species that lack the most prominent sculptural element of typical Caymanabyssia. The new subgenus Gordabyssia (of Amphiplica) pro- vides an exception to the rule that pseudococculinids are always associated with biogenic substrates. One other coc- culiniform family, the Pyropeltidae, described by MCLEAN & HASZPRUNAR (1987) occurs in the hydrothermal-vent habitat. MARSHALL (1986) defined a number of pseudococculin- id genera on characters of the radula, protoconch, and external anatomy; HASZPRUNAR (1988a) added anatomical definitions, recognizing a total of 11 genera. Two subfam- ilies were originally defined by MARSHALL (1986), the Pseudococculininae and Caymanabyssinae, in large part on radular characters. Diagnoses were altered by HASZPRUNAR (1988a:175-176), who questioned the valid- ity of radular characters as a basis for subfamily distinc- tions and based his own definitions on gill and protoconch characters. However, the utility of a two-fold subdivision is questioned here because the new species Amphiplica (Gordabyssia) gordensis has gill characters of Cayman- abyssinae and protoconch characters more typical of Pseu- dococculininae. Accordingly, a subfamily division is not recognized here. Until more is known about how characters combine in this family it may be premature to arrive at a robust classification. ACKNOWLEDGMENTS I am especially grateful to Dr. Cindy Van Dover of Woods Hole Oceanographic Institution, who was aboard the ex- peditions of the Alvin when the specimens were collected, for preserving the specimens of each of the four species and forwarding them to me. She has also read the manu- script and provided helpful comments. I thank Clif Coney for operating the scanning electron microscope at the Cen- ter for Electron Microscopy and Microanalysis, University of Southern California, and Bertram C. Draper for the photos of preserved animals. I thank reviewers Carole S. JebiMcEean, 1991 Hickman, Gerhard Haszprunar, and Bruce A. Marshall for helpful suggestions. LITERATURE CITED HAszPRUNAR, G. 1988a. Anatomy and affinities of pseudococ- culinid limpets (Mollusca: Archaeogastropoda). Zoologica Scripta 17:161-180. HASZPRUNAR, G. 1988b. Comparative anatomy of cocculini- form gastropods and its bearing on archaeogastropod sys- tematics. Pp. 7-16. In: W. F. Ponder (ed.), Prosobranch Phylogeny, Proceedings of a Symposium Held at the 9th International Malacological Congress, Edinburgh, 1986. Malacological Review, Supplement 4. HickMaNn, C.S. 1983. Radular patterns, systematics, diversity, and ecology of deep-sea limpets. The Veliger 26(2):73-92. MarsSHALL, B. A. 1986. Recent and Tertiary Cocculinidae and Pseudococculinidae (Mollusca: Gastropoda) from New Zea- land and New South Wales. New Zealand Journal of Zo- ology 12:505-546. Page 47 McLEan, J. H. 1988. Three new limpets of the family Pseu- dococculinidae from abyssal depths (Mollusca, Archaeogas- tropoda). Zoologica Scripta 17(2):155-160. McLEaNn, J. H. 1990. Neolepetopsidae, a new docoglossate limpet family from hydrothermal vents and its relevance to patellogastropod evolution. Journal of Zoology, London 222: 485-528. McLgEan, J. H. & G. HASZPRUNAR. 1987. Pyropeltidae, a new family of cocculiniform limpets from hydrothermal vents. The Veliger 30(2):196-205. MoskaLeEv, L. I. 1976. On the generic classification in Coc- culinidae (Gastropoda, Prosobranchia). Trudy Instituta Okeanologii Imeni P. P. Shirshov Akademiya Nauk SSSR 99:59-70 [in Russian]. TurRNER, R. D. 1978. Wood, mollusks, and deep-sea food chains. Bulletin of the American Malacological Union, 1977:13-19. VAN Dover, C. L., J. F. GRASSLE & M. Bouprias. 1990. Hydrothermal-vent fauna of Escanaba Trough (Gorda Ridge). Pp. 285-287. In G. R. McMurray (ed.), Gorda Ridge: A Seafloor Spreading Center in the United States’ Exclusive Economic Zone. Springer-Verlag: New York. The Veliger 34(1):48-55 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 A New Species of Flabellina (Nudibranchia: Aeolidacea) from Oshoro Bay, Japan YOSHIAKI J. HIRANO Kominato Laboratory, Marine Ecosystem Research Center, Faculty of Science, Chiba University, Amatsukominato-cho, 299-55, Japan ALAN M. KUZIRIAN Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA Abstract. Flabellina amabilis sp. nov. from Oshoro Bay, western Hokkaido, Japan, is described and illustrated. The living animal can be distinguished easily from closely related species by the particular patterns of white coloration on the body, the morphology of the foot corners, the ceratal arrangement, the position of the anus and gonopore, and the unique shape of its penis. INTRODUCTION During the course of an ecological survey on Flabellina athadona (Bergh, 1875) at Oshoro Bay (Sea of Japan), western Hokkaido (see map, HIRANO & HIRANO, 1985), a new and closely related species also belonging to the Flabellinidae was found during the same season. This paper describes the external and internal morphology of this new species and compares it with closely allied con- geners. All descriptions are based upon living animals because the discrimination between this species and F. athadona is especially difficult after preservation. Although we have examined hundreds of specimens, only specimens selected for the type series are described and figured. DESCRIPTION Flabellina amabilis Hirano & Kuzirian, sp. nov. (Figures 1-7) Type material: Holotype, National Science Museum of Tokyo (catalogue number NSMT-M0O66330), specimen collected 26 February 1985, Oshoro Bay, Hokkaido, Ja- pan. Ten paratypes, NSMT-M0O66331, from the same sample; color transparencies also on file. Distribution and habitat: Despite the fact that various localities in Hokkaido and Honshu, mainland Japan, have been sampled, this species has been found only at Oshoro Bay, western Hokkaido. Specimens were found on athecate hydroid colonies of Eudendrium boreale Yamada, 1954, attached to intertidal or subtidal rocky substrates. Etymology: This species is named for its charming ap- pearance and countenance when seen alive and in its nat- ural habitat. The Japanese name “Pirika-minoumiushi”’ is assigned: “pirika” means pretty or beautiful in the Ainu (the language of Ainu) and “minoumiushi” means aeolid nudibranch in Japanese. External morphology: Body translucent white, with pale orange or salmon pink viscera. Diverticula of digestive gland within cerata reddish orange, carmine, or sometimes tan to dark brown. Opaque white specks on dorsal surfaces of tips of oral tentacles, and entire distal half of rhino- phores; basally, white coloration only on dorsal surface of rhinophores. Cerata with opaque white dots or flecks oc- curring sparsely around distal half of ceratal surfaces, seldom found on lower half. Similar opaque white flecks restricted to central line on dorsal tail surface; not found on any other dorsal body surface (Figures 1, 2A). Y. J. Hirano & A. M. Kuzirian, 1991 Page 49 Figure 1 Flabellina amabilis Hirano & Kuzirian, sp. nov. A. Dorsal view of live animal, illustrating short, pointed anterior foot corners (arrow) and opaque white stripe occurring on tail only (arrowhead). B. Dorsal view of another animal with its long, conical penis everted (scales = 3.0 mm). Extended body length to 26 mm. Body long, high, but length from anterior end; tail approximately one-fifth to not very narrow in comparison of width-to-length pro- one-seventh of body length. portions. Notal brim prominent and continuous; pericar- Foot equaling width of visceral portion of body, lateral dium situated between one-half and one-third of body margin flared, undulate, extending with long gentle taper Page 50 The Veliger, Vol. 34, No. 1 by, Figure 2 Flabellina amabilis. A. Diagrammatic illustration of 15-mm-long animal, depicting general body form, ceratal arrangement, and patterns of opaque white body coloration on oral tentacles, rhinophores, and tail. B. Schematic diagram of ceratal clusters and branching patterns (scales = 2.0 mm). to pointed tail; anterior foot margin with transverse labial groove, slightly notched medially; anterior foot corners only slightly pointed, not tentaculiform and difficult to distin- guish in preserved material (Figure 3). Oral tentacles about one-fifth to one-sixth of body length, tapering gradually to rounded tip. Rhinophores slightly longer and narrower than oral tentacles, moderately ta- pered to bluntly tipped. Oral tentacles with smooth surface; rhinophores slightly verrucose. Cerata arranged in five to six clusters; most posterior cluster difficult to distinguish bilaterally. First and second cluster with five to six loosely defined rows, remainder with three to four rows (Figure 2B); lateral cerata lining notal brim very small, medial ones longest. Each fully developed ceras fusiform, lanceolate to linear in outline; cnidosac prominent, ovoid or conical. Interhepatic space small. Anus pleuroproctic, lying be- low third or fourth ceratal row of second cluster, just ventral to notum. Renal pore clearly visible and situated within 1 mm anterior to anus and slightly more dorsal. Gonopore located beneath anterior to middle of first ceratal cluster (Figure 3). Buccal cavity: Jaws ovoid with prominent masticatory border bearing 5 or 6 rows of distinct denticles (Figure 4). Oral glands absent; pair of typical, elongate salivary glands present with ducts passing through circumoesophageal nervous system and entering buccal mass on each side of oesophagus. Radula triseriate, formula equals 13-17 x 1- 1-1. Rachidian tooth with 5-7 denticles bilaterally, den- ticles slightly curved toward large central cusp. Lateral teeth sickle-shaped with 6-8 denticles on inner side (Figure >): Reproductive system: System androdiaulic (Figures 6, 7; especially see Figure 7 for a functional description of the reproductive system). Gonad large, pale orange to salmon pink; follicles tightly packed with moderately small, female acini peripherally. Pre-ampullary duct runs centrally within gonad, along right side of main posterior ceratal duct; duct expands into ampulla of only one loop from which emerges narrow post-ampullary duct, lying below bursa and within folds of mucous gland. Distally, duct divides into oviduct and prostatic vas deferens. Proximal oviduct loops posteriorly and expands into large bulbous Y. J. Hirano & A. M. Kuzirian, 1991 A Figure 3 Flabellina amabilis. A. Sketch of animal’s anterior right side illustrating positions of anus (a), renopore (r), common gonopore (g) with everted conical penis (p), and short, pointed anterior foot corners (arrows) (scale = 2.0 mm). B. Ventral view of the animal. Figure 4 Flabellina amabilis. Diagram of single jaw plate with denticulate masticatory border (scale = 120 wm). Figure 5 Flabellina amabilis. Scanning electron microscopic image of three complete radular teeth rows, illustrating central rachidian and lateral (2) tooth morphology (scale = 20 um). serial receptaculum seminis, which continues anteriorly as distal oviduct and enters albumen gland. Prostatic vas de- ferens long, smooth, muscular, consisting of 4 or 5 tightly coiled loops; distally tapers into small preputium. Penis long, thin, unarmed with sharply pointed tip surrounded by thin membranous sheath (Figure 1B). Nidamental and penial apertures contained in common external gonopore. Bursa copulatrix bulbous with long narrow duct inserting dorsally into nidamental duct, just internal to gonopore. Reproductive cycle: Spawning with large numbers of egg masses has been observed yearly during the winter season (late December-early April) at Oshoro Bay from 1983 to 1988. The egg mass consists of a thin undulate coil (type B; Hurst, 1967) containing singly encapsulated eggs mea- suring 60-65 wm in diameter. The capsule itself is oval and measures 90-100 wm long by 70-85 wm wide. Em- bryos develop into planktotrophic veligers with spiralled, type I shells (THOMPSON, 1961). DISCUSSION GOSLINER & GRIFFITHS (1981) regarded Coryphella Gray, 1850, as a junior subjective synonym of Flabellina Voigt, 1834, on the basis of priority, after comparing the simi- Page 52 The Veliger, Vol. 34, No. 1 Figure 6 Flabellina amabilis. Diagram of reproductive system depicting configuration and placement of major components: alb, albumen gland; amp, ampulla; be, bursa copulatrix; bw, portion of external body wall; d-ov, distal oviduct; j, junctional separation of male and female pallial gonoducts; mem, membrane gland; mu, mucous gland; ni/v, nidamental/vaginal opening; ovt, ovotestis; p, conical penis; pcd, posterior ceratal duct; po-a, post-ampullary duct; p-ov, proximal oviduct; pr, prostatic vas deferens; pre-a, pre-ampullary duct; pu, preputium; rf, cross-section of reproductive follicle illustrating peripherally developing oocytes, medially developing sperm, and small basal ductule emptying each follicle into pre-ampullary duct; rs, receptaculum seminis. larities and differences between the two genera. The taxon Flabellina, as it now stands, comprises a widely divergent and ponderous assemblage of species, especially when one considers the extremes in plesiomorphic and derived char- acters. However, if the taxon is analyzed by species, there is a continuum of overlapping character states throughout. Therefore, we have tentatively accepted this taxonomic change, but realize that the synonymy has not gained uni- versal acceptance. Flabellina amabilis sp. nov. can be distinguished from its congeners reported from the Sea of Japan and Pacific coasts of Japan on the basis of numerous morphologic characters (Table 1). When compared with living speci- mens of F. abei (BABA, 1987a), F. amabilis can be identified by the presence of an opaque white line on the tail only and dorsal surfaces of the tips of the oral tentacles. The head of F. abei has a bold, opaque-white letter ““Y” in the center, while the oral tentacles bear a white line along the posterior surface. Flabellina abei also possesses a common genital atrium with the gonopore located on the right side below the center of the first ceratal cluster, and the anus is located at the posterior edge of the interhepatic space below the first row of cerata of the second cluster. In contrast, F. amabilis has no genital atrium and the com- Y. J. Hirano & A. M. Kuzirian, 1991 Figure 7 Page 53 Flabellina amabilis. Schematic representation of distal gland mass of reproductive system, depicting major components with their function: endogenous sperm (solid sperm heads) and oocytes (solid circles) in arrested metaphase traverse the ampulla (amp) to junction (j) where male and female pallial gonoducts separate; oocytes travel through oviduct (ov), receptaculum seminis (rs) where exogenous sperm (open sperm heads) are stored embedded within lining epithelium and fertilization putatively occurs, then into female gland mass (fgm) where eggs are encapsulated and collated into egg ribbon before exiting via nidamental opening; endogenous sperm travel through prostatic vas deferens (pr) and during copulation are deposited by penis (p) into female vaginal opening (common with nidamental opening in this species); these now exogenous sperm are initially received in bursa copulatrix (bc) which dissolves prostatic secretions, thus allowing sperm to move into receptaculum seminis (rs) for nourishment and storage. Table 1 Morphologic characters of major Japanese species of Flabellina. F. amabilis F. abet F. athadona Character state White coloration Body Oral tentacles Cerata Ceratal arrangement Notum Foot corners Anal position, 2nd ceratal cluster Gonopore, 1st ceratal cluster Genital atrium (common) Penis Radular formula Denticulation Rachidian teeth Lateral teeth Central cusp of rachidian + BaBA (1987b). tail stripe only speckled speckled tips 5-6 clusters; 3-6 rows/cluster distinct small, pointed row 3-4 anterior half absent conical 13-17 x 1-1-1 6-9 6-8 long, wide head only; letter “Y” stripe; posterior edge speckled, white tips 5 clusters distinct long, tentacular row 1 center present conical 15 x 1-1-1 6-9 11-12 long, thin Y-shaped, dorsal stripe; tip oral tentacles to tail stripe; as above speckled 6 clusters; 5-6 rows/cluster distinct; less interhepatic space rounded row 3 anterior half present; vestibular glands “false”’t 19-22 x 1-1-1 4-5 8-9 short, wide Page 54 The Veliger, Vol. 34, No. 1 mon gonopore bearing the separate penial and nidamental openings is located beneath the anterior half of the first ceratal cluster. The color pattern of the other closely related species, F. athadona (Bergh, 1875), which has been de- scribed from living animals (BABA, 1987b), consists of a Y-shaped mid-dorsal white stripe extending from the tips of the oral tentacles to the tail. The gonopore of F. athadona, as diagrammed by BaBA (1987b), serves as the opening for a common genital atrium and is located below the anterior half of the anterior right ceratal cluster. The anus of this species and of F. amabilis is similarly located be- neath the third row of cerata of the second cluster. All three species can also be distinguished from each other using the morphology of the anterior foot corner. Flabellina abei has long, tentacular foot corners, while in F. amabilis they are only slightly pointed; F. athadona has rounded foot corners, resembling the condition generally found in most Eubranchidae and Tergipedidae. The radular morphology of each species is also specific. Flabellina abe: and F. amabilis have similar numbers of rows of teeth (15 vs. 13-17, respectively), but the two species differ markedly in rachidian tooth morphology, especially in the central cusp; the cusp is long and thin in F. abe: and long and wide in F. amabilis. The lateral teeth of F. abet have many more medial denticles, although the basic sickle shape is similar in both. The character of 19- 22 teeth rows in F. athadona is different from the previous two species, as is the rachidian tooth morphology and the smaller number of lateral denticles (4 or 5 only). The specific differences between the three congeners also extend to the reproductive systems. Flabellina athadona dif- fers in the shape of the penis, which consists of a folded and rolled extension of the preputial lining (false penis; BaBA, 1987b) and also possesses a vestibular or preputial gland located at the posterior end of the preputium (per- sonal observation; BABA, 1987b). Flabellina abei possesses a short conical penis distal to a short thick prostatic vas deferens and a common genital atrium or vestibule. The penis is also conical in F. amabilis, but the vas deferens is considerably longer than that which BaBa (1987a) fig- ured for F. abet. Flabellina amabilis also has separate male and female gonoporal openings contained in a common gonopore. All three species possess a saccular bursa copula- trix with a long narrow duct, but the insertion points into the nidamental duct differ among the species. The recep- taculum seminis of F. athadona is semi-serial, while it is completely serial in F. amabilis. BABA (1987b) did not describe or figure either the oviduct or receptaculum for F. abei. Of the other flabellinids known from the Sea of Japan, Flabellina amabilis differs from F. orientalis (Volodchenko, 1941) on the basis of radular morphology (the number of teeth rows, and the shape and denticulation pattern of rachidian and lateral teeth), the shape of the rhinophores, ‘oot, and the possession of nonclustered cerata. Fla- bellina amabilis can be distinguished from F. verrucosa (Sars, 1829) reported from the Sea of Japan (VOLODCHEN- KO, 1955), on the basis of radular and penial morphology, as well as body coloration. Flabellina alder: (Adams, 1861), described from specimens collected off Matsumae, Hok- kaido (Strait of Tsugaru), was cited by BERGH (1885) and listed by Marcus (1961) as an uncertain species. Based on the cursory Latin description given by ADAMS (1861) of the general body shape and coloration, there are simi- larities between F. alderi and F. amabilis. However, the two appear to differ in the morphology and coloration of the oral tentacles and rhinophores. When compared with the other described flabellinid species, Flabellina amabilis most closely resembles F. grac- iis (Alder & Hancock, 1844). The general body mor- phology and ornamentation, with the opaque white stripes on the oral tentacles, rhinophores, and tail, are similar in both species, as is the possession of a conical penis. The animals differ externally, however, in that F. gracilis has longer, acutely pointed foot corners, an anus beneath the first row of the second ceratal cluster, and a gonopore located below the posterior half of the first cluster. Al- though both species have similar numbers of radular teeth rows, the rachidian teeth of F. gracilis are broader (length to width ratio), while the central cusp is shorter and nar- rower. Differences are also found in the reproductive anat- omy of the two species, both in the shape of the receptacula seminis and in the length and number of coils of the am- pulla. It is interesting to note that these two species, Flabellina amabilis and F. gracilis, appear to occupy similar ecolog- ical niches in their respective distributional ranges. Both species are stenotrophic in their prey selection and are found associated with species of the athecate hydroid Eu- dendrium (KUZIRIAN, 1979). They share the same pref- erences for hard rocky substrates. They also have similar seasonal occurrences and lay identical undulating coiled egg masses (type B; Hurst, 1967), which they deposit around and among the branches of their hydroid prey. Flabellina amabilis is found sympatrically with F. atha- dona in Oshoro Bay. Because the two species are often difficult to distinguish as preserved specimens, identifica- tion of living animals is preferable for ecological investi- gations. Details on the ecological relationships between these two species will be reported in a later paper. ACKNOWLEDGMENTS We thank Dr. Yayoi M. Hirano of Kominato Laboratory, MERC, Chiba University, for her discovering the exis- tence of this species and for providing so much useful information. Thanks are extended also to Mr. Kazuro Shinta of Oshoro Marine Biological Station, Hokkaido University, for his generous help in obtaining specimens and field data under extremely cold field conditions and for his continuous encouragement. We are indebted to Mr. Gary McDonald, of the Joseph M. Long Marine Labo- Y. J. Hirano & A. M. Kuzirian, 1991 ratory, University of California, Santa Cruz, California, for furnishing information and literature on the Flabel- linidae. This study was supported in part by a Grant-in- Aid for Scientific Research (mainly Nos. 59740324 and 61740439) from the Ministry of Education, Science and Culture of Japan. This is contribution No. 296 from the Mukaishima Marine Biological Station. LITERATURE CITED ADAMS, A. 1861. On some new species of Mollusca from the north of China and Japan. Annals and Magazine of Natural History (3)8:135-142. BaBA, K. 1987a. A new species of Coryphella from Toyama Bay, Japan (Nudibranchia: Flabellinidae s./.). Venus (Jap- anese Journal of Malacology) 46:147-150. BaBA, K. 1987b. Anatomical review of Coryphella from Akkeshi Bay, Hokkaido, northern Japan. Venus (Japanese Journal of Malacology) 46:151-156. BERGH, R. 1875. Beitrage zur Kenntnis der Aecolidiaden. III. Verhandlungen der k.k. Zoologisch-Botanischen Gesell- schaft in Wien 25:633-658. BERGH, R. 1885. Beitrage zur Kenntnis der Aeolidiaden. VIII. Verhandlungen der k.k. Zoologisch-Botanischen Gesell- schaft in Wien 35:1-60. GosLINER, T. M. & R. J. GRIFFITHS. 1981. Description and revision of some South African aeolidacean Nudibranchia Page 55 (Mollusca, Gastropoda). Annals of the South African Mu- seum 84:105-150. Hirano, Y. J. & Y. M. HIRANO. 1985. Preliminary study on the feeding ecology of the aeolid nudibranch, Coryphella atha- dona Bergh, 1875, with special reference to nematocysts in the ceras. Special Publication from the Mukaishima Marine Biological Station 1985:161-166. Hurst, A. 1967. The egg masses and veligers of thirty North- east Pacific Opisthobranchs. The Veliger 9:255-288. Kuzirian, A. M. 1979. Taxonomy and biology of four New England coryphellid nudibranchs (Gastropoda: Opistho- branchia). Journal of Molluscan Studies 45:239-261. Marcus, Er. 1961. Opisthobranch mollusks from California. The Veliger 3(Suppl.):1-85. Sars, M. 1829. Bidrag til s6edyrenes naturhistorie. 1:1-59. Bergen. THompson, T. E. 1961. The importance of the larval shell in the classification of the Sacoglossa and the Acoela (Gastrop- oda: Opisthobranchia). Proceedings of the Malacological So- ciety of London 43:233-238. VOLODCHENKO, N. I. 1941. New species of nudibranch mol- luscs from far eastern seas of the U.S.S.R. Investigations of the Far Eastern Seas of the U.S.S.R. 1:53-68. VOLODCHENKO, N.I. 1955. Subclass Opisthobranchia. Pp. 247- 252. In: E. N. Pavlovskii (ed.), Atlas of the Invertebrates of the Far Eastern Seas of the U.S.S.R. Akademia Nauk SSSR. Zoologischeskii Inst. 240 pp. THE VELIGER © CMS, Inc., 1991 The Veliger 34(1):56-66 (January 2, 1991) ‘Taxonomic and Geographical Range Data on ‘Two Rare Species of Okenza (Gastropoda: Nudibranchia: Doridacea) from the Eastern Atlantic by J. L. CERVERA Laboratorio de Biologia, Facultad de Ciencias del Mar, Universidad de Cadiz, Apdo. 40, 11510 Puerto Real (Cadiz), Spain P. J. LOPEZ-GONZALEZ anp J. C. GARCIA-GOMEZ Laboratorio de Biologia Marina, Departamento de Fisiologia y Biologia Animal, Facultad de Biologia, Universidad de Sevilla, Apdo. 1095, 41080 Sevilla, Spain Abstract. The Atlantic species of Okenia aspersa Alder & Hancock, 1845, is redescribed from one specimen from southern Portugal collected during the International Marine Biological Expedition “ALGARVE-88.” In addition, another rare species of Okenia, O. mediterranea (Ihering, 1886), is redescribed from specimens from southern Spain. Geographical range data for both species are included. Finally, we compare our specimens with the descriptions provided by other authors. INTRODUCTION Until now, the only species of the genus Okenia Menke, 1830, recorded from the Iberian Peninsula was O. impexa Marcus, 1957, found in the Cabo de Palos, Mediterranean (TEMPLADO, 1982). However, during the International Marine Biological Expedition “ALGARVE-88” (south- ern Portuguese coasts) (May-June 1988), organized by the MNHN of Paris (P. Bouchet) and the INIP of Por- tugal (L. Saldanha), one specimen of a species of Okenia not previously recorded from the Iberian coasts was col- lected: O. aspersa Alder & Hancock, 1845. In addition, during sampling along the southern Spanish coasts (El Portil, Huelva) in Spring 1989, 22 specimens of another species of Okenia that we had never seen were collected. We have concluded that these specimens belong to O. med- iterranea (Ihering, 1886). In this paper, we present new taxonomic and geographical range data for both species. Family GONIODORIDIDAE H. & A. Adams, 1854 Okenia Menke, 1830 Okenia aspersa Alder & Hancock, 1845 Material: One specimen, 8 mm in length, collected by SCUBA at 31 m depth in Sagres, Portugal (37°N, 8°55’W), 20 May 1988. Description: The body bears spicules and a narrow pallial ridge with 16 simple appendages, of which the anterior 4 are elongate, while the remainder are shorter. The frontal velum is slightly bilobed (Figure 1A). The rhinophores, having 43 lamellae, are a little longer than the anterior appendages (Figure 1D). The branchial tuft has 11 uni- pinnate gills (Figure 1E). The spicules lie within the in- tegument and up to the tips of the pallial ridge appendages (Figure 1C). The genital pore opens on the right of the anterior third of the animal’s body. ple C@erverave: aly 990i Page 57 & CCU Figure 1 Okenia aspersa. A. Dorsal view of the specimen. B. Detail of one of the pallial ridge appendages. C. Arrangement of the spicules within these appendages. D. Detail of a rhinophore. E. Detail of a gill. Key: bye, bright yellow; drb, dark reddish brown; hw, hyaline white; ow, opaque white; rb, reddish brown; ye, yellow. Page 58 0014 20K te The Veliger, Vol. 34, No. 1 . ‘ ~ 1@vm W032 Figure 2 Okenia aspersa. A. Detail of some elements of the cuticular labial armature (drawn with a camera lucida). B. Lateral view of one of these. C. Scanning electron micrographs of these elements. The ground color of the body, rhinophores, gills, and appendages is reddish brown. Small areas of the flanks, veil, and tail, as well as the rhinophores, gills, and ap- pendages, display a darker color. Yellow patches, some brighter than others, exist on the rhinophores, gills, ap- pendages, and the entire body, except the ventral surface of the foot. The tips of the rhinophores and appendages are hyaline white. Also present are small scattered opaque white spots on the flanks, veil, and tail. The tail has a white middle line from the gills to almost its tip (Figure 1A, B, D, E). The labial cuticular armature is composed of two areas of elongate elements, which do not form a complete ring around the mouth. These elements have a single smooth cusp and a hole on which the posterior elements lie (Figure 2A, B, C). The radular formula of the specimen is 26 x 1:1-0-1-1. The innermost teeth bear 10-12 strong den- ticles on the cusp, while the outermost have a prominent smooth cusp (Figure 3A, B). The reproductive system (Figure 4A) has a white ampulla, slightly curved at its distal end. The elongate and flattened prostate forms a loop and connects with a long and folded duct that ends in an elongate penis with numerous penial spines (Figure 4B, C). The gametolytic gland is spherical and opens out- wardly through a long and thin vaginal duct that forms a loop before it widens in its distal region. The thin allosperm Ee Cervera cial, 1991 duct starts from the gametolytic gland close to the vaginal duct. The pyriform seminal receptacle enters the allosperm duct close to the gametolytic gland. Geographical range: Okenia aspersa has been recorded in Norway (THOMPSON & BRown, 1984; JUsT & EDMUNDs, 1985; PLATTs, 1985), Denmark (Just & EDMUNDs, 1985; PLATTS, 1985), Shetlands Isles (THOMPSON & BROWN, 1984; PLATTS, 1985), British Isles (THOMPSON & BROWN, 1984; PLATTS, 1985), Atlantic France (BOUCHET & TARDY, 1976, according to THOMPSON & BRowNn, 1984), and Mas- sachusetts, USA (Mors, 1972). So, our specimen con- stitutes the most southern record of this species and the first record on the Iberian Peninsula. Discussion: According to Lemche (see JUST & EDMUNDS, 1985) the differences that he observed between the spec- imen attributed to Okenia aspersa and those of ALDER & HANCOCK (1845-1855) are probably due to Alder & Han- cock’s inaccurate description. The specimen of O. aspersa of THOMPSON & BROWN (1976, 1984) agrees with Alder & Hancock’s description. According to JUsT & EDMUNDS (1985), O. aspersa is clearly identical with O. ascidicola Morse, 1972, from Massachusetts, and, further, Lemche thought that O. pulchella Alder & Hancock, 1854, was conspecific with O. aspersa. However, Morse (1972) com- pared her material with O. pulchella and concluded that they are different. ALDER & HANCOCK (1845-1855) de- scribed O. pulchella with denticulate innermost radular teeth, while THOMPSON & BROWN (1984) described smooth innermost radular teeth in a specimen attributed to this species. In addition, some authors (PRUVOT-FOL, 1954; SCHMEKEL & PORTMANN, 1982) considered O. aspersa con- specific with O. quadricolor (Montagu, 1815), but THOMPSON & BROWN (1984) reached the opposite con- clusion after scrutiny of Montagu’s description. Our specimen is quite similar to those of MoRsE (1972) and Lemche (see JUST & EDMUNDS, 1985), although it lacks the mid-dorsal appendage before the branchial tuft that is present in these latter. MORSE’s (1972) brief de- scription of the reproductive system does not permit its comparison with ours. Okenia mediterranea (Ihering, 1886) Material: (1) Seven specimens of 3.5-8.5 mm in length, collected intertidally, El Portil (Huelva, Spain) (37°12'40’N, 7°7'50”W), 6 April 1989. (2) Eleven speci- mens, 5-7.5 mm in length, collected intertidally, El Portil (Huelva, Spain), 23 April 1989. (3) Four specimens, 6 mm in length, collected intertidally, El Portil (Huelva, Spain), 6 May 1989. All specimens have been deposited in the Laboratorio de Biologia Marina, Departamento de Fisiologia y Biolo- gia Animal, Universidad de Sevilla. Page 59 @G16 20K A? OG Figure 3 Okenia aspersa. A. Radular teeth of a half-row. B. Scanning electron micrographs of the same. Description: The body bears spicules and a narrow pallial ridge with 18-24 appendages that are simple, except that the two most posterior appendages on each side join at their bases. The two most anterior appendages are elon- gate, the following two are slightly smaller, and the re- maining are short and similar to each other in length. The frontal velum is slightly bilobed (Figures 5, 6A). The rhinophores have 12-20 lamellae and the two most anterior appendages are longer (Figure 6D, a and b). The branchial tuft has 5-9 unipinnate gills, which have 3-15 laminae (Figure 6E). The prominent anal papilla is located in the Page 60 The Veliger, Vol. 34, No. 1 Imm 330um Figure 4 Okenia aspersa. A. Reproductive system. B. Detail of the penis. C. Detail of the penial spines. Key: amp, ampulla; dd, deferent duct; fgl, female gland; ggl, gametolytic gland; hd, hermaphroditic duct; p, penis; pr, prostate; sr, seminal receptacle; vd, vaginal duct. Figure 5 Okenia mediterranea. A. Specimen 6 mm in length, 6 April 1989. B. Seven specimens, one 8 mm, five 3 mm, and one 5 mm in length, 6 April 1989, on Alcyonidium cf. mytili; arrow indicates the spawn of the species. J. L. Cervera et al., 1991 Page 61 Page 62 The Veliger, Vol. 34, No. Figure 6 Okenia mediterranea. A. Dorsolateral view of one specimen. B. Arrangement of the spicules within the pallial ridge appendages. C. Arrangement of the spicules below the notal crests and elevations. D. Anterior (a) and lateral (b) view of a rhinophore. E. Detail of a gill. Key: hw, hyaline white; ow, opaque white; ye, yellow; ye + br, yellow + blood red. et Cervera-ec al, 119911 65um 2 ea Meee pes ey Oia 30um Figure 7 Okenia mediterranea. Different types of spicules observed in this species. middle of the branchial tuft. A conspicuous keel-shaped crest formed by four elevations runs from the rhinophores towards the gills. In the same way, three or four elevations in a line (sometimes two) are usually present on both sides of this crest (Figure 6A). The spicules lie within the in- tegument (Figure 7) and form a network in the foot and flanks of the animals. The spicules are also in the tips of the pallial ridge appendages (Figure 6B) and are arranged, in the same way, under the crest and the notal elevations (Figure 6C). The genital pore opens on the right flank of the animal, behind the rhinophoral level. The ground color of the body (Figure 6A) is hyaline white suffused by an opaque white pigmentation that cov- ers the dorsum and frontal veil. There is a yellow spot on the corner of each frontal velum. Yellow pigment is also on the mid-apical surface of all the appendages, the central crest, and the flanking elevations, as well as on the mid- apical surface of the gills and the middle line of the tail. Red pigment covers the yellow, except on the spots of the frontal velum. Both colors may combine to form orange. Scattered red spots of different sizes are also on the opaque white pigmentation of the dorsum, flanks, and tail of the animal. The yellow and red pigments of the two most anterior appendages almost cover their whole surface and the pallial edge that joins them, except in one 3.5-mm- long specimen. The rhinophores are hyaline white, but are covered by the above-mentioned opaque white pig- mentation on their anterior faces, except on their bases, and apical third of the posterior faces (Figure 6D, a and b). The gills are hyaline white in those parts not covered by the yellow and red pigments (Figure 6E). The internal anatomy of this species is represented in Figure 8. The labial armature is composed of two areas of elongate cuticular elements, which do not form a com- Page 63 Figure 8 Okenia mediterranea. Internal anatomy. Key: a, anus; aa, anterior aorta; amp, ampulla; au, auricle; bm, buccal mass; cns, central nervous system; dgl + hgl, digestive gland + hermaphroditic gland; ggl, gametolytic gland; i, intestine; pe, pericardium; sgl, salivary gland; sr, seminal receptacle; st, stomach; v, ventricle. plete ring around the mouth. Each element has an edge with 3-5 denticles (Figure 9A). The radular formula of one 8.5-mm-long specimen is 25 x 1-1-0-1-1. The in- nermost radular teeth have 28-31 small denticles on each cusp, while the outermost teeth lack denticles and possess a prominent cusp slightly hooked and curved inwards (Fig- ure 9B, D). The reproductive system (Figure 10A) has a large, white ampulla. The prostate, elongate and flattened, forms a loop and connects with a long deferent duct that ends in an elongate, cylindrical penis with numerous penial spines (Figure 10B). The nacreous albumen gland con- nects with the mucous gland near the start of the prostate. The gametolytic gland is spherical and opens outwardly through a thin vaginal duct that forms two loops before widening in its distal part. The thin allosperm duct starts Page 64 The Veliger) Voly34Nowml OO einige ae Figure 9 Okenia mediterranea. A. Scanning electron micrograph of some elements of the cuticular labial armature. B. Innermost (1) and outermost (2) radular teeth of a half-row (drawn with a camera lucida). C. Scanning electron micrograph of the radular teeth. D. Scanning electron micrograph of a detail of the cusp of an outermost tooth. from the gametolytic gland close to the vaginal duct. The seminal receptacle joins the allosperm duct close to the gametolytic gland. Biology: All specimens were found on the ctenostomate bryozoan Alcyonidium cf. mytili Dalyell, 1848. Some egg masses of this species were collected on this substrate and others were observed in the laboratory. The spawn is a semicircular string (Figure 5B), circular in section, and in some cases the spawn almost forms a ring. The diameter i jut 1 mm and the strings have a length of 10-12 mm. vach capsule contains one egg. The eggs are almost spher- ical and white. The diameter of the capsules is 71.5-97.5 um and that of the eggs is 58.5-78 wm. Geographical range: Okenia mediterranea has previously been recorded at its type locality, Naples, Italy, in the Mediterranean (IHERING, 1886; SCHMEKEL, 1979; SCHMEKEL & PORTMANN, 1982). Our specimens constitute the first record of this species from the Atlantic Ocean and the Iberian Peninsula. Discussion: Although our specimens differ slightly from the specimens of Okenia mediterranea from Naples pls Genveraretial=) 1991 jes B Payiis Page 65 Imm se jw —+/ | *% | Bit Gem" uOge Figure 10 Okenia mediterranea. A. Reproductive system. B. Scanning electron micrograph of the penis. Key: amp, ampulla; agl, albumen gland; hd, hermaphroditic duct; mgl, mucous gland; p, penis; pr, prostate; sr, seminal receptacle; vd, vaginal duct. (IHERING, 1886; SCHMEKEL, 1979; SCHMEKEL & PORTMANN, 1982), we prefer provisionally to consider our specimens as belonging to this species. SCHMEKEL (1979) corrects her own record of specimens of O. amoenula Bergh, 1907 (SCHMEKEL, 1968), which really correspond to O. mediterranea, and discusses the differences between the two species. SCHMEKEL (1979) reports the differences between her specimens of O. mediterranea and those described by IHERING (1886), emphasizing the contradictions of this author when he described the species: for example, Ihering wrote that the mantle was smooth, but drew two tubercles on each side of the median crest. However, IHERING (1886) Page 66 The Veliger, Vol. 34, No. 1 did not mention the unpaired ceras located behind the gills that was described by SCHMEKEL (1979). We agree with Schmekel that the specimen attributed to this species by Pruvot-FoL (1951, 1954) corresponds neither to O. amoenula nor O. mediterranea. The descriptions of the Okenia mediterranea specimens from Naples do not specify clearly whether the body pig- mentation is white hyaline suffused by an opaque white or whether the body lacks this latter. Moreover, the ar- rangement of the red pigmentation of the notum of our specimens is slightly different from that on the specimens of Naples. The red and yellow colors of the appendages of Atlantic specimens cover at most the apical half, while in the Mediterranean specimens they cover almost their entire length. These latter specimens have rhinophores that are completely opaque white, while ours do not. Other differences between the Mediterranean specimens and ours are the presence of three or four elevations in a line on both sides of the median crest and the absence of the unpaired ceras behind the gills observed in some of the specimens of SCHMEKEL (1979) and SCHMEKEL & PORTMANN (1982). The base of the innermost radular teeth of our specimens is broader than in Schmekel’s spec- imens. This variability could be due to the observation of the radular teeth with a little variation in their arrange- ment (for instance, see the differences that can be observed between the radular teeth of the same specimen of Okenia aspersa in Figure 3A, B). The incomplete description of the reproductive system of Schmekel’s specimens (SCHMEKEL, 1979), as well as the absence of drawings in Ihering’s and Schmekel’s descrip- tions of this system do not permit a good comparison with that described in this paper. SCHMEKEL (1979) points out that the situs of this system in her specimens “corresponds in the main features with the situs of Okenia amoenula Bergh, 1907 (MacnagE, 1958: fig. 23), and she does not find differences between the reproductive systems of the two species. However, com- paring the reproductive system of our specimens with that of O. amoenula, differences can be observed: the prostate of our specimens is broader and shorter than in O. amoen- ula, the joint of the seminal receptacle with the allosperm duct is closer to the gametolytic gland in our specimens, and the seminal receptacle of our animals is different in size (larger) and shape (not pyriform). In addition to having these differences in the reproduc- tive system, Okenia amoenula has smooth elements on the labial armature (BERGH, 1907) and different coloration. Thus, we conclude that our material belongs to a different species. Despite the impossibility of comparing the repro- ductive system of our specimens with that of the material from Naples, we consider them both provisionally as O. mediterranea. ACKNOWLEDGMENTS We deeply thank Dr. P. Bouchet for his kind invitation to participate in the International Marine Biological Ex- pedition “ALGARVE-88,” in which the specimen of Okenza aspersa was collected, and the Electron Microscopy Service of the University of Cadiz, mainly Mr. Juan Gonzalez, for providing scanning electron microscopy facilities. This paper has been partially supported by the project “Fauna Ibérica I’? DGICYT PB87-0397. LITERATURE CITED ALDER, J. & A. HANcocK. 1845-1855. A Monograph of the British Nudibranchiate Mollusca. Ray Society: London. Part 1 (1845); Part 2 (1846); Part 3 (1847); Part 4 (1848); Part 5 (1851); Part 6 (1854); Part 7 (1855). BERGH, L.S.R. 1907. The Opisthobranchiata of South Africa. Transactions of the South African Philosophical Society 17(1): 1-144, pls. 1-4. BoucHeET, P. & J. TARDY. 1976. Faunistique et biogéographie des nudibranches des cétes frangaises de |’Atlantique et de la Manche. Annales de |’Institut Océanographique 52(2): 205-213. IHERING, H. VON. 1886. Beitrage zur Kenntnis der Nudibran- chien des Mittelmeeres. II]. 4. Die Polyceraden. Malako- zoologische Blatter N.F. 8:12-48. Just, H. & M. EpMunps. 1985. North Atlantic nudibranchs (Mollusca) seen by Henning Lemche. Ophelia supplement 2:1-150. Macnak, W. 1958. The families Polyceridae and Goniodoridi- dae (Mollusca, Nudibranchiata) in Southern Africa. Trans- actions of the Royal Society of South Africa 35(4):341-373. Morse, P. 1972. Biology of Okenia ascidicola spec. nov. (Gas- tropoda: Nudibranchia). The Veliger 15(2):97-101. Piatts, E. 1985. An annotated list of the North Atlantic Opis- thobranchia (excluding Thecosomata and Gymnosomata). Ophelia supplement 2:150-170. Pruvot-FoL, A. 1951. Etude des nudibranches de la Medi- terranée. Archives de Zoologie Experimentale et Génerale 88:1-80. PruvoT-Fot, A. 1954. Mollusques Opisthobranches. Fauna de France. 58:1-460. Paul Lechevalier: Paris. SCHMEKEL, L. 1968. Ascoglossa, Notaspidea und Nudibranchia im litoral des Golfes von Neapel. Revue Suisse de Zoologie 75(6):103-155. SCHMEKEL, L. 1979. First record of Okenia impexa Marcus, 1957 from the Western Atlantic in the Mediterranean. The Veliger 21(3):355-360. SCHMEKEL, L. & A. PORTMANN. 1982. Opisthobranchia des Mittelmeeres. Springer-Verlag: Berlin. 410 pp., pls. 1-36. TEMPLADO, J. 1982. Datos sobre los opistobranquios del Cabo de Palos (Murcia). Bollettino Malacologico 18(9-12):247- 254. TuHompson, T. E. & G. H. Brown. 1976. British Opistho- branch Molluscs. Synopses British Fauna (N.S.) 8:1-203. Academic Press: London. TuHompson, T. E. & G. H. Brown. 1984. Biology of Opis- thobranch Molluscs. Vol. II. Ray Society: London. 229 pp. The Veliger 34(1):67-72 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 New Early Eocene Species of Arca s.s. (Mollusca: Bivalvia) from Southern California by RICHARD L. SQUIRES Department of Geological Sciences, California State University, Northridge, California 91330, USA Abstract. Two new species of the warm-water marine bivalve Arca s.s. are reported from the early Eocene of Ventura County, southern California. They represent the earliest species of Arca s.s. known from the Pacific coast of North America. Arca (Arca) filewiczi sp. nov. is from the early early Eocene part of the ‘““Meganos Stage” in the upper Santa Susana Formation, north side of Simi Valley, southern California. Arca (Arca) givensi sp. nov., a previously unnamed species from the middle early Eocene “Capay Stage,” part of the Juncal Formation, Pine Mountain area, southern California, is now named and described. INTRODUCTION The living arcid bivalve Arca s.s. has worldwide distri- bution in tropical and warm seas (REINHART, 1935). There is no agreement as to when Arca s.s. first appeared in the fossil record. It has been reported from strata of Early Cretaceous age in southern England (Woops, 1899; REIN- HART, 1935; CASEY, 1961:605). NEWELL (1969), however, reported its geologic range to be Late Cretaceous to Recent. Arca s.s. does not show up in the fossil record of the Pacific coast of North America until early Eocene time, based on my recent discovery of A. (A.) filewiczi sp. nov. in rocks of this age in southern California. Because this new species has no Cretaceous or Paleocene ancestral spe- cies of Arca s.s. in the Pacific coast region of North America (REINHART, 1943; Moore, 1983), it must have immigrated into southern California. Like many other Old World mollusks that immigrated into southern California during the early Eocene, the route of migration was most likely by way of Central America (SQUIRES, 1987). The time of arrival of Arca s.s. into California coincided with a world- wide warming trend (Haq, 1981). Previously, the earliest record of Arca s.s. from the Pa- cific coast of North America was A. (A.) n. sp.? Givens, 1974, from strata of middle early Eocene age, southern California. This species is herein named and described as A. (A.) givensi sp. nov. The terms ““Meganos Stage” and “Capay Stage” used in this report refer to Pacific coast of North America pro- vincial megainvertebrate stages as used by SAUL (1983) who regarded the ‘““Meganos Stage” as late Paleocene to early early Eocene and the restricted ““Capay Stage” of GIVENS (1974) as middle early Eocene. Abbreviations used for catalog and/or locality numbers are: CSUN, California State University, Northridge; LACMIP, Natural History Museum of Los Angeles County, Invertebrate Paleontology Section; UCR, Uni- versity of California, Riverside. STRATIGRAPHIC OCCURRENCES AND GEOLOGIC AGES Arca (A.) filewiczi was found in the upper part of the Santa Susana Formation at locality CSUN 965 (Figure 1) at 518 m (1700 ft) elevation, on the east side of an abandoned oil-well road long the west side of a ridge, 137 m (450 ft) south and 792 m (2600 ft) east of the northwest corner of section 32, T3N, R17W, Santa Susana quad- rangle (7.5 minute), 1951, north side of Simi Valley, Ven- tura County, California. The locality is about 100 m strat- igraphically below the basal conglomerate of the Llajas Formation, which disconformably overlies the Santa Su- sana Formation. No age-diagnostic microfossils have ever been found in this part of the Santa Susana Formation. Earliest Eocene calcareous nannofossils, however, have been found in the immediately underlying strata, and using this information FILEWIcz & HILL (1983:fig. 5) assigned an early Eocene age (CP9 Zone of OKADA & Bukry, 1980) to the upper 100 m of the Santa Susana Formation on the north side of Simi Valley. This age is equivalent to the Page 68 San Rafael Peak x @ Loc. UCR 4667 X=— Sespe Hot Springs Fillmore Oak Ridge mountain CSUN 965 Big @ Simi Valley Figure 1 Geographic occurrences of two new species of early Eocene Arca s.s. in southern California. early early Eocene part of the “Meganos Stage,” and SAUL (1983) assigned the upper 100 m of the Santa Susana Formation on the north side of Simi Valley to this stage. Two specimens of Arca (A.) filewiczi were found, and one is complete. They are from a lens of greenish gray, very fine sandstone surrounded by sandy siltstone. Asso- ciated macrofossils were abundant specimens of the gas- tropod Turritella andersoni susanae Merriam, 1941, and rare specimens of the brachyuran crabs Cyclocoryestes al- dersont Squires, 1980, and Zanthopsis hendersonianus Rathbun, 1926. The fossils in the lens are interpreted to be a very slightly transported assemblage in a relatively shallow offshore environment. This interpretation is in agreement with what HEITMAN (1983) found on the basis of his paleoecologic study of benthic foraminifers from this formation. He discovered that although paleobathymetry for the Santa Susana Formation on the north side of Simi Valley was mostly restricted to the bathyal realm, the upper part represents a shoaling event associated with basin filling that deposited silty sandstone just above the shelf-slope break. Arca (A.) givensi was found in the lower part of the The Veliger, Vol. 34, No. 1 Juncal Formation at locality UCR 4667 (Figure 2) at 1097 m (3600 ft) elevation, on the east side of a south- draining tributary to Hot Springs Canyon, 518 m (1700 ft) south and 427 m (1400 ft) east of the northwest corner of section 21, T6N, R20 W, Topatopa Mountains quad- rangle (7.5 minute), 1943, Ventura County, California (GIVENS, 1974). The locality is about 53 m stratigraphi- cally above the base of the Juncal Formation, and GIVENS (1974) assigned this part of the Juncal Formation to the Turritella uvasana infera fauna of the middle early Eocene “Capay Stage.” Nineteen specimens of Arca (A.) givensi were found, and all are single valves. They are from a greenish gray sandstone bed within a predominantly mudstone facies. Associated macrofossils listed by GIVENS (1974:table 1) are other bivalves and some gastropods, including Turr- tella andersoni Dickerson, 1916. GIVENS (1974) interpreted that the rocks surrounding locality UCR 4667 were de- posited in a nearshore, tropical or subtropical shallow- marine environment. SYSTEMATIC PALEONTOLOGY Family ARCIDAE Lamarck, 1809 Subfamily ARCINAE Lamarck, 1809 Genus Arca Linné, 1758 Type species: By subsequent designation (SCHMIDT, 1818), Arca noae Linneé, 1758, ICZN Opinion 189, 5 October 1944. Subgenus Arca s:s. Arca (Arca) filewiczi Squires, sp. nov. (Figures 2-6) Diagnosis: Medium size, with a weak posterior umbonal flexure, two to three radial bands on post-umbonal slope, and slightly concave ligamental area with four chevron- shaped grooves. Description: Medium size, rhombic, very inequilateral, umbones prominent, beaks approximately one-fourth of length of shell from anterior end. Weak posterior umbonal flexure. Anterior margin parallel with posterior margin, both meeting straight hinge line at a nearly 90° angle. Ventral margin straight. Entire shell U-shaped in profile. Ligamental area extremely wide, slightly concave in um- bonal area and slightly convex in posterior region of shell. Ligamental area with four chevron-shaped grooves in vi- cinity of beak, smooth posteriorly. Ligamental area on each valve subrectangular in shape, widest just posterior of beak. Medial sulcus from umbonal area to posterior end of byssal sinus on ventral surface of each valve; growth lines on right valve more deflected by the sinus than on left valve. Shell with fine cancellate sculpture; two to three fairly prominent radial bands on post-umbonal area. Radial ribs also di- R. L. Squires, 1991 Explanation of Figures 2 to 11 Figures 2 to 6. Arca (Arca) filewiczi Squires, sp. nov., holotype, LACMIP 8365, locality CSUN 965, x1.2. Figure 2: left valve. Figure 3: right valve. Figure 4: dorsal view. Figure 5: ventral view. Figure 6: anterior view. Figures 7 to 11. Arca (Arca) givensi Squires, sp. nov., locality UCR 4667. Figure 7: paratype, UCR 4667/132, left valve, x10. Figure 8: holotype, UCR 4667/131, right valve, x6.9. Figures 9-11: paratype, UCR 4667/133. Figure 9: dorsal view, x 5.8. Figure 10: oblique dorsal view, x5.8. Figure 11: interior, x 6.2. rectly beneath beaks, extending a small distance onto lig- amental area. Holotype: LACMIP 8365. Type locality: Locality CSUN 965, north side of Simi Valley, Ventura County, southern California. Paratype: LACMIP 8366. Dimensions: Of holotype, height 24 mm, length 59 mm, single-valve thickness 13 mm; of paratype, height 8 mm, length 11 mm (incomplete), single-valve thickness 3 mm. Discussion: The morphologic characteristics of Arca s.s. have been described by REINHART (1935) and Nopa (1966). Some of the most important of these are a wide ligamental area and an elongate posterior region with a depressed area between the hinge line and umbonal flexure. The new species has all of the requisite external characters. Unfortunately, no internal features could be observed without destroying the only two specimens of the new species. The match of external morphology, however, is sufficient to assign the new species to Arca s.s. Arca (A.) filewiczi most resembles A. (A.) biangula La- Page 70 The Veliger, Vol. 34, No. 1 MARCK (1805: 219; 1807: pl. 17, figs. 2a, b, expl. p. 238; PALMER, 1977: pl. 24, figs. 5a, b, c; GOSSMANN & PISSARRO, 1904-1906: pl. 35, fig. 110-1; BRITISH MUSEUM (NATURAL History), 1975: pl. 6, fig. 10) from early Eocene (Cuisian Stage) through late Eocene (Bartonian Stage) strata in the Paris Basin, France, and Hampshire Basin, southern En- gland. Arca (A.) filewiczi was compared to a specimen of A. (A.) biangula from the UCMP Cloez collection of Paris Basin Paleogene mollusks, as well as to published figures of A. (A.) biangula. These comparisons revealed that A. (A.) filewiczi differs from A. (A.) brangula in the following features: much weaker posterior umbonal flexure, beaks one-fourth rather than one-fourth to one-third of length of shell from anterior end, fewer and less prominent radial ribs on post-umbonal slope, four rather than six chevron- shaped grooves in ligamental area, chevron-shaped grooves confined to beneath umbonal area rather than throughout ligamental area, ligamental area on each valve more rec- tangular in shape rather than triangular, and a much smaller byssal gape. Arca (A.) filewiczi differs from A. (A.) givensi in the following features: six times larger, much weaker posterior umbonal flexure, beaks one-fourth rather than one-third of length of shell from anterior end, anterior and posterior margins both meet hinge line at a nearly 90° angle rather than curve to meet the hinge line, fewer and less prominent radial ribs on post-umbonal slope, four rather than one chevron-shaped groove in ligamental area, and a much more prominent byssal sinus on each valve. On the basis of recent work by Moore (1983), the only other Eocene Arca s.s. known from the Pacific coast of North America is A. (A.) hawleyi REINHART (1943:21-22, pl. 2, figs. 19-22) from late Eocene ““Tejon Stage”’ strata in southern California (REINHART, 1943; WEAVER & KLEINPELL, 1963). Arca (A.) fllewiczi differs from A. (A.) hawley: in the following features: shell does not narrow posteriorly, weaker commarginal ribs, and four rather than three chevron-shaped grooves in ligamental area. Etymology: The species is named for M. V. Filewicz for his long-term cooperation in providing calcareous nan- nofossil age dates for many Paleogene formations on the Pacific coast of North America. Occurrence: Early early Eocene part of the “Meganos Stage,” upper Santa Susana Formation, north side of Simi Valley, Ventura County, southern California, locality CSUN 965. Arca (Arca) givensi Squires, sp. nov. (Figures 7-11) Arca (Arca) n. sp.? GIVENS, 1974: 40, pl. 1, fig. 8. Diagnosis: Small size, with a strong posterior umbonal flexure, six to eight primary ribs on post-umbonal slope, and a flattish ligamental area with one chevron-shaped groove. Description: Small size, rhombic, very inequilateral, um- bones prominent, beaks approximately one-third of length of shell from anterior end, beaks overhang ligamental area. Strong carina-like posterior umbonal flexure. Anterior margin parallel with posterior margin, both curving to- ward straight hinge line. Ventral margin fairly straight. Ligamental area flat throughout, with one chevron-shaped groove in vicinity of beak, smooth elsewhere. Ligamental area widest opposite beak. Slight medial sulcus from um- bonal area to center of ventral margin of each valve where there appears to be a slight byssal sinus. Shell with fine to fairly strong cancellation ornamentation. Radial ribbing strongest on post-umbonal slope with six to eight fairly strong radial ribs, interspaces with no interribs or with one or more interribs, the number increasing ventrally. Only portions of dentition observed; small, numerous teeth below beak and at least four large elongate teeth on pos- terior end. Holotype: UCR 4667/131 (formerly UCR hypotype 4667/131). Type locality: Locality UCR 4667, Pine Mountain area, Ventura County, southern California. Paratypes: UCR 4667/132 and 4667/133. Dimensions: Of holotype, height 3 mm, length 7 mm, single-valve thickness 1.5 mm; of paratype, UCR 4667/ 132, height 2 mm, length 4.5 mm, single-valve thickness 1 mm; of paratype, UCR 4667/133, height 4.5 mm, length 10 mm, single-valve thickness 2 mm. Discussion: Nineteen specimens of the new species were collected by GIvENs (1974). Eight are right valves, seven are left valves, and four are fragments. No complete spec- imens were found. All of the specimens are small, and they may represent juveniles. The external morphologic features of this new species, as well as the very small part of the dentition area that could be observed, match those described by NopDaA (1966) for Arca s.s. Arca (A.) givensi is most similar to A. (A.) hatchetigbeensis Harris (1897:47, pl. 7, figs. 10-10a; TOULMIN, 1977:183- 184, pl. 11, figs. 9-10) from the early Eocene Hatchetigbee Formation in southwestern Alabama (TOULMIN, 1977). Arca (A.) givensi differs from A. (A.) hatchetigbeensis in the following features: half the size, six to eight rather than only two radial ribs on the post-umbonal slope, and one rather than two chevron-shaped grooves in the liga- mental area. Arca (A.) givensi is also similar to A. (A.) merriami (VAN WINKLE, 1918:pl. 81, pl. 6, fig. 1; CLARK, 1925:80, pl. 13, figs. 5-8; WEAVER, 1943:pl. 66-67, pl. 11, fig. 8, pl. 12, figs. 3, 6-9, 12, 15) from Oligocene strata in the Grays Harbor area of southwestern Washington. Arca (A.) givensi differs from A. (A.) merriami in the following fea- tures: half the size, beaks approximately one-third rather than one-fourth of length of shell from anterior end, more R. L. Squires, 1991 prominent radial ribs on post-umbonal slope, and presence of cancellate sculpture. Arca (A.) merriami closely resem- bles A. (A.) washingtoniana Dickerson, 1917, from Oli- gocene strata in southwestern Washington, and EFFINGER (1938) considered them to be the same species. Arca (A.) givensi differs from A. (A.) filewiczi in the following features: one-sixth the size, much stronger pos- terior umbonal flexure, beaks one-third rather than one- fourth of length of shell from anterior end, anterior and posterior margins both curve to meet hinge line rather than intersect it at a nearly 90° angle, twice as many and less prominent radial ribs on post-umbonal slope, one rather than four chevron-shaped grooves in the ligamental area, and a much less obvious byssal sinus on each valve. Etymology: The new species is named for C. R. Givens for this valuable contributions on Paleogene marine mol- lusks of North America. He also found the specimens of the new species. Occurence: Middle early Eocene “Capay Stage” Turri- tella uvasana infera fauna of the Juncal Formation, Pine Mountain area, Ventura County, southern California, lo- cality UCR 4667. ACKNOWLEDGMENTS M. A. Kooser (University of California, Riverside) pro- vided for loan of the requested specimens. She also supplied additional specimens that proved valuable in this study. D. R. Lindberg (University of California, Berkeley) pro- vided for a loan of a specimen from the Cloez collection. L. R. Saul (Natural History Museum of Los Angeles County) shared her knowledge of the fossil record of Arca s.s. and made available important references. LITERATURE CITED BRITISH MUSUEM (NATURAL History). 1975. British Cenozoic Fossils (Tertiary and Quaternary). 5th ed. British Museum (Natural History), Publication 540:132 pp. London. Casey, R. 1961. The stratigraphical palaeontology of the Low- er Greensand. Palaeontology 3:487-621. Crark, B. L. 1925. Pelecypoda from the marine Oligocene of western North America. University of California Publications, Department of Geological Sciences, Bulletin 15:69-136. CossMaANN, A. E. M., & G. PissaRRO. 1904-1906. Iconogra- phie completé des coquilles fossiles de ]’Eocéne des environs de Paris. Vol. 1. H. Bouillant: Paris. 45 pls. DIcKERSON, R. E. 1916. Stratigraphy and fauna of the Tejon Eocene of California. University of California Publications, Department of Geology, Bulletin 9:363-524. DIcKERSON, R. E. 1917. Climate and its influence upon the Oligocene faunas of the Pacific coast, with descriptions of some new species from the Molopophorus lincolnensis Zone. Proceedings of the California Academy of Sciences, Series 4, 7:157-192. EFFINGER, W. L. 1938. The Gries Ranch fauna (Oligocene) of western Washington. Journal of Paleontology 12:355- 390. FILEwicz, M. V. & M. E. Hint, III. 1983. Calcareous nan- Page 71 nofossil biostratigraphy of the Santa Susana and Llajas For- mations, northern Simi Valley. Pp. 45-60. Jn: R. L. Squires & M. V. Filewicz (eds.), Cenozoic Geology of the Simi Valley Area, Southern California. Pacific Section, Society of Economic Paleontologists & Mineralogists: Los Angeles, California. GIvENS, C. R. 1974. Eocene molluscan biostratigraphy of the Pine Mountain area, Ventura County, California. Univer- sity of California, Publications in Geological Sciences 109: 1-107. Hag, B.U. 1981. Paleogene paleoceanography: early Cenozoic oceans revisited. Pp. 71-82. In: Oceanologia Acta, Proceed- ings, 26th International Geological Congress, Geology of Oceans Symposium. Paris. Harris, G. D. 1897. The Lignitic stage, Part 1, stratigraphy and Pelecypoda. Bulletins of American Paleontology 2:1- 102. HEITMAN, H. L. 1983. Paleoecological analysis and biostra- tigraphy of the Lower Paleogene Santa Susana Formation, northern Simi Valley, Ventura County. Pp. 33-44. In: R. L. Squires & M. V. Filewicz (eds.), Cenozoic Geology of the Simi Valley Area, Southern California. Pacific Section, Society of Economic Paleontologists & Mineralogists: Los Angeles, California. LAMARCK, J. B. P. A. 1802-1809. Memoires sur les fossiles des environs de Paris. Annales de Muséum National d’His- toire Naturelle. Vols. 1-9, 12, 14 (all variously paged). Paris. LAMARCK, J. B. P. A. 1809. Philosophie zoologique, ou ex- position des considérations relatives 4 histoire naturelle des animaux. Paris. Vol. 1:1-422; Vol. 2:1-473. LINNE, C. 1758. Systema Naturae per Regna Tria Naturae. Editio 10, reformata. Salvii: Holmiae. 824 pp. MERRIAM, C. W. 1941. Fossil turritellas from the Pacific coast region of North America. University of California, Publications of the Department of Geological Sciences, Bul- letin 26:1-214. Mookrg, E. J. 1983. Tertiary marine pelecypods of California and Baja California: Nuculidae through Malleidae. United States Geological Survey, Professional Paper 1228-A:108 pp. NEWELL, N. D. 1969. Order Arcoida Stoliczka, 1871. Pp. N248-N270. In: R. C. Moore (ed.), Treatise on Invertebrate Paleontology, Mollusca 6, Pt. N, Vol. 1 of 3. Geological Society of America and University of Kansas Press: Law- rence, Kansas. Nopa, H. 1966. The Cenozoic Arcidae of Japan. Science Re- ports of Tohoku University, Sendai, second series (Geology) 38:1-163. Oxapba, H. & D. Bukry. 1980. Supplementary modification and introduction of code numbers to the low-latitude coc- colith biostratigraphic zonation. Marine Micropaleontology 5:321-325. PALMER, K. V. W. 1977. The Unpublished Velins of Lamarck (1802-1809) Illustrations of Fossils of the Paris Basin Eo- cene. Paleontological Research Institution: Ithaca, New York. 67 pp. RATHBUN, M. J. 1926. The fossil stalk-eyed Crustacea of the Pacific slope of North America. United States National Mu- seum Bulletin 138:1-155. REINHART, P. W. 1935. Classification of the pelecypod family Arcidae. Bulletin du Musée Royal d’Histoire Naturelle de Belgique 11:1-68. REINHART, P. W. 1943. Mesozoic and Cenozoic Arcidae from the Pacific slope of North America. Geological Society of America Special Paper 47:1-117. SauL, L. R. 1983. Turritella zonation across the Cretaceous— Page 72 Tertiary boundary, California. University of California, Publications in Geological Sciences 125:1-165. SCHMIDT, F. C. 1818. Versuch tuber die beste Einrichtung zur Aufstellung, Behandlung und Aufbewahrung der verschie- den Naturkorper und Gegenstande der Kunst. Gotha. 252 PP- Squires, R. L. 1980. A new species of brachyuran from the Paleocene of California. Journal of Paleontology 54:472- 476. Squires, R. L. 1987. Eocene molluscan paleontology of the Whitaker Peak area, Los Angeles and Ventura counties. Los Angeles County Natural History Museum, Contributions in Science 388:1-93. TouLMIN, L. D. 1977. Stratigraphic Distribution of Paleocene and Eocene Fossils in the Eastern Gulf Coast Region. Mono- graph 13, Vol. 1:602 pp. Geological Survey, of Alabama. The Veliger, Vol. 34, No. 1 VAN WINKLE, K. E. H. 1918. Paleontology of the Oligocene of the Chehalis Valley, Washington. University of Wash- ington, Publications in Geology 1:69-97. WEAVER, C. E. 1943. Paleontology of the marine Tertiary formations of Oregon and Washington. University of Wash- ington, Publications in Geology 5:1-789. WEAVER, D. W. & R. M. KLEINPELL. 1963. Mollusca from the Turritella variata zone. Pp. 81-118. Jn: R. M. Kleinpell & D. W. Weaver (eds.), Oligocene Biostratigraphy of the Santa Barbara Embayment, California. University of Cal- ifornia, Publications in Geological Sciences, Vol. 43. Woops, H. 1899. A monograph of the Cretaceous Lamelli- branchia of England. Vol. 1. Paleontographical Society of London 53:1-72. The Veliger 34(1):73-77 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 New Morphologic and Stratigraphic Data on Calyptogena (Calyptogena) gibbera Crickmay, 1929 (Bivalvia: Vesicomyidae) from the Pliocene and Pleistocene of Southern California RICHARD L. SQUIRES Department of Geological Sciences, California State University, Northridge, California 91330, USA Abstract. The dentition of the fossil vesicomyid marine bivalve Calyptogena (Calypotogena) gibbera Crickmay, 1929a, previously has not been described, and the holotype is missing and presumed lost. Recent discovery of specimens from the original lot now allows for complete description and illustration of this species, as well as for the designation of a lectotype. Comparison with other fossil and Recent Calyptogena from the northeastern Pacific reveals that C. (C.) lasia Woodring, 1938, is a junior synonym of C. (C.) gibbera. The geologic range of C. (C.) gibbera is now early Pliocene to middle Pleistocene, and the species is confined to the Los Angeles and Ventura basins, southern California. INTRODUCTION Three species of the vesicomyid marine bivalve Calyptogena have been reported from the fossil record of southern Cal- ifornia. They are C. (Calyptogena) pacifica Dall, 1891, C. (C.) gibbera Crickmay, 1929a, and C. (C.) lasia (Woodring, 1938). They are all from Pliocene of Pleistocene strata. Hinge dentition is essential in the recognition of species of Calyptogena, but the hinge dentition of C. (C.) gibbera was unknown. Although CRICKMaAyY (1929a:fig. 1) figured the right-valve exterior of his species Calyptogena (C.) gub- bera, he did not figure nor describe the dentition. His figured specimen, which was designated as a holotype (un- numbered), was not stored in a repository, and, to date, the specimen has not been found. Unfortunately, new ma- terial from the type locality on Deadmans Island, San Pedro Bay, southern California, can never be collected because the island was destroyed in 1928 in order to widen the main channel into the inner harbor of Los Angeles Harbor (WoopDRING et al., 1946; WEINSTEIN, 1967). Without any diagnostic morphologic criteria available for Calyptogena (C.) gibbera, paleontologists have been un- able to report any other occurrences of this species. Re- cently, however, George L. Kennedy of the Natural His- tory Museum of Los Angeles County Invertebrate Paleontology Section brought to my attention that the mu- seum has 16 specimens of C. (C.) gibbera that Crickmay collected and identified from the type locality of his species (equivalent to locality LACMIP 30252). The specimens are also most probably from the original lot. The purpose of this article is to illustrate the hinge dentition of C. (C.) gibbera, based on the discovery of these very important specimens. This information will be essential in any future study of the evolutionary history of this interesting genus, which can be an important faunal member of Recent deep- sea hydrothermal vent communities (Boss & TURNER, 1980) and of Recent and Tertiary cold-seep communities related to subduction zones (OHTA & LAUBIER, 1987; KANNO et al., 1989; NIITSUMA et al., 1989; GOEDERT & SQUIRES, in press). Abbreviations used for catalog and/or locality numbers are: LACMIP, Natural History Museum of Los Angeles County, Invertebrate Paleontology Section; USGS, United States Geological Survey; USNM, United States National Museum. Page 74 SYSTEMATIC PALEONTOLOGY Family VESICOMYIDAE Dall & Simpson, 1901 Genus Calyptogena Dall, 1891 Type species: By monotypy, Calyptogena pacifica Dall, 1891. Subgenus Calyptogena s.s. Calyptogena (Calyptogena) gibbera Crickmay, 1929a (Figures 1-4) Calyptogena gibbera CRICKMAY, 1929a:93, fig. 1; 1929b:623; WOoODRING et al., 1946:83; BERNARD, 1983:50. Calyptogena (?Calyptogena) gibbera Crickmay: Boss & TURNER, 1980:186. Phreagena lasia WOODRING, 1938:50-52, text-fig. 2a, pl. 5, figs. 3-4. Calyptogena lasia (Woodring): WINTERER & DURHAM, 1962: 295, 302, 307, 308; Boss, 1968:739. Calyptogena (Phreagena) lasia (Woodring): KEEN, 1969:N664, figs. E138 10a, b. Calyptogena (Calyptogena) lasia (Woodring): Boss & TURNER, 1980:187. Original descriptions: Calyptogena (C.) gibbera—“‘This new form is to be distinguished from the living type by its outline and proportions: length 52 mm, height 29 mm, diameter 15 mm. The new species somewhat resembles C. elongata but has a greater height and an arched post- umbonal slope, whence the trivial name. All the dimen- sions, but especially the length, are greater than those of C. pacifica.”” (GRICKMAY, 1929a:93) Calyptogena (C.) lasia—‘Moderately large, elongate, thick-shelled. Lunule absent; escutcheon long, abruptly angulated and flattened. Sculpture consisting of strongly defined growth lines. Hinge of right valve consisting of a short, weak anterior cardinal, a heavy bifid middle car- dinal, and a bifid posterior cardinal. Hinge of left valve consisting of a heavy anterior cardinal, joined to a heavy bifid middle cardinal, and a posterior cardinal. Adductor and pedal muscle scars deep sunk. Pallial line apparently simple. ” (WOODRING, 1938:50) Discussion: Of the 16 specimens of Calyptogena (C.) gib- bera in the LACMIP collection, four are left valves, six are right valves, and six are articulated. All of the single valves show dentition. Two of the articulated specimens show the dentition of both valves, and one of the articulated specimens shows the dentition of one valve. They are most- ly fairly well preserved, especially with regard to the den- tition, and one of these specimens (LACMIP 8400) is herein designated as the lectotype of C. (C.) gibbera. The lectotype is close in size to that of the missing and presumed lost holotype. The dimensions of the lectotype are length 50.5 mm, height 25.5 mm, and width (=diameter) ap- proximately 6.5 mm. Two of the other topotypes are fig- ured (Figures 1, 2) in this present report and are now hypotypes, LACMIP 8398 and 8399. The other 13 spec- imens are topotypes and are stored in the LACMIP col- The Veliger, Vol. 34, No. 1 lection under locality LACMIP 30252 in the Pleistocene invertebrate fossil cabinets. A comparison of the dentition and shell shape of Ca- lyptogena (C.) gibbera with other species of Calyptogena reveals that the fossil C. (C.) lasta (WOODRING, 1938:50- 52, text-fig. 2a, pl. 5, figs. 3, 4) is a junior synonym of C. (C.) gibbera, based on the examination of the holotype of C. (C.) lasia and the examination of 38 specimens of C. (C.) lasia (identified by Woodring) from locality LACMIP 21363 in the Towsley Formation, Ventura County, which is discussed below. For documentation of this determina- tion, compare Figures 1-4 of C. (C.) gibbera with Figures 5-8 of C. (C.) lasia. CRICKMAY’s (1929a) description of Calyptogena (C.) gib- bera is inadequate because it consists of only a brief com- parison of his species to some other species of this genus. WoOoDRING’s (1938) description of C. (C.) lasta is much more complete and, therefore, is also given above. Nev- ertheless, there are some variations in morphology that WOODRING (1938) did not mention. The right valve middle cardinal and posterior cardinal vary in the strength of how bifid they can be—namely, from fairly well developed to weak. In addition, although nearly all specimens are fairly elongate in shape, a few are ovate. It is important to mention that the anterior cardinal of Calyptogena (C.) gibbera is very thin and short. To be able to recognize it in a specimen requires at least good pres- ervation of the hinge. Previously, Calyptogena (C.) gibbera was known only from its type locality at Deadmans Island (CRICKMay, 1929a, b). Specimens were from a 12-cm-thick layer of hard gray shale that weathered to a rusty yellow. CRICKMAY (1929b) assigned this shale layer, which contained only the species C. (C.) gibbera and Lucinoma acutilineata (Con- rad), to his zone No. 2. ARNOLD (1903) had included the shale in the San Diego Formation, but SMITH (1912) and CRICKMAY (1929a, b) included it in the Santa Barbara beds. CLARK (1931:37) and WOODRING et al. (1946), how- ever, put CRICKMAY’s (1929b) zone No. 2 in the Timms Point Silt. According to G. L. Kennedy (personal com- munication), the Timms Point Silt is of middle Pleistocene age. Calyptogena (C.) lasia is known from lower Pliocene strata in southern California, predominately the Repetto Formation and, to a lesser extent, the Pico Formation of the Los Angeles basin (WooDRING, 1938) and near the top of the Towsley Formation, Ventura basin (WINTERER & DURHAM, 1962:295, pl. 46). The Towsley Formation locality is equivalent to locality LACMIP 21363. During the course of this investigation, a single specimen of a previously unidentified Calyptogena (C.) gibbera from locality LACMIP 11942 in the Niguel Formation, south- ern Los Angeles basin, also was detected. This is the first record of this genus from the Niguel Formation. According to VEDDER (1960, 1972), the Niguel Formation is of late Pliocene age. The only other contemporaneous species of Calyptogena R. LE. Squires, 1991 Page 75 Explanation of Figures 1 to 4 Figures 1 to 4. Calyptogena (Calyptogena) gibbera Crickmay, 1929, locality LACMIP 30252 = locality University of California, Los Angeles 6613. Figures 1, 2: left valves; Figure 1: hypotype and topotype, LACMIP 8398, exterior (posteriormost area missing), x 1.3; Figure 2: hypotype and topotype, LACMIP 8399, hinge (anterior end of anterior cardinal is missing), 1.5. Figures 3, 4: lectotype, LACMIP 8400, right valve; Figure 3: exterior, x1.1; Figure 4: hinge, x 2.3. Explanation of Figures 5 to 8 Figures 5 to 8: Calyptogena (Calyptogena) lasia (Woodring, 1938). Figures 5, 6: left valves; Figure 5: hypotype, LACMIP 8401, locality LACMIP 21363, exterior, x1.4; Figure 6: holotype, USNM 496097, locality USGS 13864, hinge, x2.1. Figures 7, 8: right valves; Figure 7: hypotype, LACMIP 8402, locality LACMIP 21363, exterior, X1.3; Figure 8: holotype, USNM 496097, locality USGS 13864, hinge, x 2.2. Page 76 The Veliger, Vol. 34, No. 1 s.s. from southern California is C. (C.) pacifica Dall, 1891. It has been reported from an oil-well corehole in Pliocene deposits in Beverly Hills, California (GRANT & GALE, 1931:278), and it is most commonly reported as a Recent species, known from Clarence Strait, southern Alaska, to the Santa Barbara Channel, southern California (OLDROYD, 1925; Boss & TURNER, 1980), in depths rang- ing from 550 to 1950 m (BERNARD, 1983). It also has been reported from Mio-Pliocene and Pliocene deposits of Ja- pan (OTuUKA, 1937; OTATUME, 1942; KANNO et al., 1989). As can be seen from the illustrations in WOODRING (1938: fig. 2b), in BERNARD (1974:text-fig. 2A), in Boss (1968: figs. 16, 17, 19, 20), and in Boss & TURNER (1980:fig. 10b, c), the dentition of C. (C.) pacifica is markedly dif- ferent from that of C. (C.) gibbera. In C. (C.) pacifica, the anterior cardinal in both valves parallels the valve margin rather than diverging from it, and the right middle cardinal is overlapped by the anterior cardinal rather than con- verging with it in the direction of the beak. The shell of C. (C.) pacifica is also not as elongate. BERNARD (1983) reported that C. (C.) gibbera is the same as C. (C.) pacifica, but this is not the case. During the examination of mollusks associated with specimens of Calyptogena (C.) gibbera from locality LAC- MIP 21363 near the top of the Towsley Formation in the Ventura basin, three adult and seven juvenile specimens C. (C.) pacifica were found. This is the only known record of the two species occurring together. The only other living species of Calyptogena s.s. from the northeastern Pacific is C. (C.) kilmeri1 BERNARD (1974: 17-18, text-figs. 1B, 2B, 3B, 4E), known from British Columbia to northern California in depths ranging from 800 to 1200 m (BERNARD, 1983). Although BERNARD (1974) placed his species in the subgenus Archivesica, Boss & TURNER (1980) placed the species in Calyptogena s:.s. because its dentition and anatomy are so similar to those of C. (C.) pacifica, the type species of Calyptogena. Calyp- togena (C.) kilmeri differs from C. (C.) pacifica and C. (C.) gibbera in not having a right posterior cardinal. Occurrence: Lower Pliocene through middle Pleistocene, southern California. ACKNOWLEDGMENTS I am most grateful to G. L. Kennedy (Natural History Museum of Los Angeles County, Invertebrate Paleontol- ogy Section) for bringing to my attention the various lots of Pliocene and Pleistocene Calyptogena in the museum’s collection. Without his willingness to share his knowledge of the collection, this research would not have been possible. George L. Kennedy, F. J. Collier (National Museum of Natural History), and C. Coney (Natural History Mu- seum of Los Angeles County, Malacology Section) ar- ranged for loans of specimens. The manuscript benefited from comments by Ellen J. Moore and an anonymous reviewer. LOCALITIES CITED LACMIP 11942: Elevation 236 ft, 200 m after trailers on entrance road to Marbella Country Club, San Juan Cap- istrano, Orange County, Southern California. Niguel For- mation. Age: Late Pliocene. Collector: D. Gage, 1988. LACMIP 21363: About elevation 1800 ft, in unsurveyed land on a knife-edge ridge between Tapo Canyon and an unnamed canyon west of Salt Canyon, 488 m (1600 ft) south and 701 m (2300 ft) east of hill 1991, north side of Santa Susana Mountains, Val Verde 7.5-minute quad- rangle, 1952, Ventura County, southern California. Equivalent to WINTERER & DURHAM (1962:295, 360, and pl. 46) locality F-17. Near top of Towsley Formation. Age: Late Pliocene. Collectors: B. Kelley and J. Cooper, 1942? LACMIP 30252: Near south end, west side of Deadmans Island, San Pedro, southern California. Locality destroyed in 1928. Lower part of Timms Point Silt. Locality = University of California, Los Angeles locality 6613. Age: Middle Pleistocene. Collector: C. H. Crickmay, probably about 1927. LITERATURE CITED ARNOLD, R. 1903. The paleontology and stratigraphy of the marine Pliocene and Pleistocene of San Pedro, California. California Academy of Sciences, Memoir 3:420 pp. BERNARD, F. 1974. The genus Calyptogena in British Columbia with a description of a new species. Venus 33:11-22. BERNARD, F. 1983. Catalogue of the living Bivalvia of the eastern Pacific Ocean: Bering Strait to Cape Horn. Canadian Special Publication of Fisheries & Aquatic Sciences 61:1- 102. Boss, K. J. 1968. New species of Vesicomyidae from the Gulf of Darien, Caribbean Sea (Bivalvia: Mollusca). Bulletin of Marine Science 18:731-748. Boss, K. J. & R. D. TURNER. 1980. The giant white clam from the Galapagos Rift, Calyptogena magnifica species no- vum. Malacologia 20:161-194. CiarRK, A. 1931. The cool-water Timms Point Pleistocene ho- rizon at San Pedro, California. San Diego Society of Natural History, Transaction 7:25-41. CrickMay, C. H. 1929a. On a new pelecypod Calyptogena gibbera. The Canadian Field-Naturalist 43:93. CRICKMAY, C.H. 1929b. The anomalous stratigraphy of Dead- man’s Island, California. Journal of Geology 37:617-638. DALL, W. H. 1891. On some new or interesting west American shells obtained from the dredgings of the U.S. Fish Com- mission steamer Albatross in 1888, and from other sources. United States National Museum, Proceedings 14:173-191. DALL, W. H. & C. T. Simpson. 1901. The Mollusca of Porto Rico. United States Fisheries Commission, Bulletin 20:351- 524. GoEDERT, J. L. & R. L. Squires. In press. Eocene deep-sea communities in localized limestones formed by subduction- related methane seeps, southwestern Washington. Geology. GRANT, U.S., IV & H. GALE. 1931. Catalogue of the marine Pliocene Mollusca of California. San Diego Society of Nat- ural History, Memoir 1:1036 pp. KANNO, S., K. AMANO, & H. BAN. 1989. Calyptogena (Calyp- R. L. Squires, 1991 togena) pacifica Dall (Bivalvia) from the Neogene System in the Joetsu District, Niigata Prefecture. Transactions and Proceedings, Palaeontological Society of Japan, New Series 153:25-35. KEEN, A. M. 1969. Family Vesicomyidae Dall, 1908. P. N664. In:R. C. Moore (ed.), Treatise on Invertebrate Paleontology, Pt. N. Mollusca 6 Bivalvia, Vol. 2 of 3. Geological Society of America and University of Kansas Press: Lawrence. NutsuMa, N., Y. MATSUSHIMA & D. Hirata. 1989. Abyssal molluscan colony of Calyptogena in the Pliocene strata of the Miura Peninsula, central Japan. Palaeogeography, Palaeo- climatology, & Palaeoecology 71:193-203. OuntTa, S. & L. LAuBIER. 1987. Deep biological communities in the subduction zone of Japan from bottom photographs taken during Nautile dives in the Kaido project. Earth & Planetary Science Letters 83:329-342. OLprRoypD, I. S. 1925. The Marine Shells of the West Coast of North America. Stanford University Publications, Uni- versity Series, Geological Sciences. Vol. 1, Pelecypoda. 248 PP- OtTaTuME, K. 1942. On the occurrence of fossil Calyptogena from the Isikari oil-field, Hokkaido. Journal of the Geolog- ical Society of Japan 49:435-437. OrTukA, Y. 1937. Occurrence of Calyptogena pacifica Dall from Wakimoto on Oga Peninsula. Journal of the Geological So- ciety of Japan 44:231. SMITH, J. P. 1912. Geologic range of Miocene invertebrate Page 77 fossils of California. Proceedings of the California Academy of Sciences, 4th Series 3:161-182. VEDDER, J.G. 1960. Previously unreported Pliocene Mollusca from the southeastern Los Angeles basin. Pp. B326-B328. In: Short Papers in the Geological Sciences. United States Geological Survey, Professional Paper 400-B. VEDDER, J.G. 1972. Review of stratigraphic names and mega- faunal correlation of Pliocene rocks along the southeast mar- gin of the Los Angeles Basin, California. Pp. 158-172. In: E. H. Stinemeyer & C. C. Church (eds.), The Proceedings of the Pacific Coast Miocene Biostratigraphic Symposium. Pacific Section, Society of Economic Paleontologists & Min- eralogists: Los Angeles, California. WEINSTEIN, R. A. 1967. The million-dollar mud flat. Los An- geles County Natural History Museum, Quarterly 5:26-30. WINTERER, E. L. & D. L. DURHAM. 1962. Geology of south- eastern Ventura basin, Los Angeles County, California. United States Geological Survey, Professional Paper 334- H:275-366. WoOobDRING, W. P. 1938. Lower Pliocene mollusks and echi- noids from the Los Angeles basin, California, and their in- ferred environment. United States Geological Survey, Pro- fessional Paper 190:67 pp. WOoOobpDRING, W. P., M. N. BRAMLETTE & W.S. W. KEw. 1946. Geology and paleontology of Palos Verdes Hills, California. United States Geological Survey, Professional Paper 207: 145 pp. The Veliger 34(1):78-84 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 Shallow-Water Venerid Clams (Bivalvia: Veneridae) from the Pacific Coast of Colombia JAIME R. CANTERA K. Universidad del Valle, Departamento de Biologia, A.A. 25360, Cali, Colombia Abstract. During collecting trips to several localities on the Pacific coast of Colombia between 1975 and 1986, 40 species of the bivalve family Veneridae were obtained. Three species (Pitar helenae, Protothaca metodon, and Protothaca zorritensis) are recorded for the first time on the Colombian coast, and significant new distributional information is given for several species. Notes about habitat, bathi- metric range, and geographic distribution are provided for each species. INTRODUCTION Veneridae bivalve species of the Pacific coast of Colombia, including Isla de Gorgona, were reported from several expeditions (Askoy, Albatross, and Velero) and by OLSSON (1961) and KEEN (1971), but most of these records were from moderately deep waters or from beach shells. CANTERA et al. (1979), PRAHL (1986), and COSEL (1986), in papers on mollusks of Isla de Gorgona, have increased the number of reported venerids. ESCALLON & CANTERA (1989) have given additional data in a paper about bivalves from Bahia Malaga. However, the shallow-water and intertidal bi- valves have remained almost unknown. This paper at- tempts to present a complete list of venerid bivalves along the Pacific coast of Colombia, from Punta Ardita (7°28’N, 77°55'W) to Cabo Manglares (1°32'N, 79°02'W), includ- ing Isla de Gorgona (Figure 1). THE STUDY AREA The Pacific coast of Colombia is a tropical area with several biotopes, including sandy beaches, cliffs, rocky shores, mudflats, and mangroves. In the north, from Cabo Cor- rientes to Panama, there is the coastal Cordillera Baudo, which is composed of basic and ultrabasic rocks. The south is dominated by mangroves on aluvial lowlands in tidal swamps and sandy beaches in the mouths of estuaries. The climate is characterized by abundant rain (500 cm/yr) and moderate air temperatures. There is a wide tidal range (about 4 m between high and low water), currents of moderate speed, high water temperatures, and low salin- ities. MATERIALS anD METHODS During 10 years (1975-1986), several localities between Punta Ardita in the north and Cabo manglares in the south, including Isla de Gorgona, were visited in search of live and dead mollusks. Collecting was done by hand in inter- tidal areas, skin and SCUBA diving in shallow water, and shrimp nets in deeper water. Mollusks were fixed in 5% formalin and then transferred to 75% alcohol. They were identified in the laboratories of malacology of the De- partment of Biology of the University of Valle, Cali, Co- lombia. All material is deposited in the reference collection of Marine Biology of the University of Valle (C.R. B.M.U.V.). The habitats given here are those where the species were found in this study, and the dimensions are those of the largest specimen. RESULTS SYSTEMATIC ACCOUNT Class Bivalvia Subclass Heterodonta Order Veneroida Superfamily Veneroidea Family VENERIDAE Subfamily VENERINAE Periglypta multicostata (Sowerby, 1835) OLsson, 1961:293, pl. 50, fig. 3-3b. KEEN, 1971:161, fig. 380. ee Ganteranke 1991 Page 79 PACIFIC OCEAN ee ee ee Figure 1 The Pacific coast of Colombia showing the study localities: 1. Punta Ardita; 2. Bahia Octavia; 3. Ensenada de Utria; 4. Ensenada Catripe; 5. Charambira; 6. Bahia de Malaga (Figure 1a); 7. Bahia de Buenaventura (Figure 1b); 8. Golfo de Tortugas; 9. Punta Coco; 10. Isla de Gorgona (Figure 1c); 11. Guapi; 12. Mulatos; 13. Vigia; 14. Tumaco (Isla de Gallo); 15. Tumaco (Bocagrande). Figure 1a. Bahia de Malaga: 1. Archipelago de la Plata; 2. Punta La Muerte; 3. Isla Curichichi; 4. Los Negros; 5. Playa Chucheros; 6. Juanchaco; 7. Ladrilleros; 8. Isla Monos; 9. Isla E] Aguante. Figure 1b. Bahia de Buenaventura: 1. Isla E] Cangrejo; 2. La Bocana; 3. Punta Soldado. Figure 1c. Isla de Gorgona: 1. Playa Pizarro; 2. Muelle; 3. Playa Blanca; 4. Gorgonilla (Estrecho de Tasca). Page 80 Material: Ensenada de Utria, Isla de Gorgona (Muelle, Playa Blanca, Gorgonilla). Habitat: Sandy-rocky beaches at extreme low tide. Size: 92 mm length, 88 mm height Range: Gulf of California to Punta Verde, Peru, and Ga- lapagos Islands. Globivenus isocardia (Verrill, 1870) OLsson, 1961:292, pl. 50, fig. 2. KEEN, 1971:162, fig. 381. Material: Punta Ardita, Ensenada de Utria, Isla de Gor- gona (Playa Pizarro). Habitat: Mostly offshore between 20 and 80 m. Substrate unknown. Size: 80 mm length. Range: Gulf of California to Manta, Ecuador. KEEN (1971) gives Isla de Gorgona as the southern limit. Subfamily MERECTRICINAE Twela (Pachydesma) argentina (Sowerby, 1835) OLSSON, 1961:270, pl. 44, fig. 1. KEEN, 1971:162, fig. 384. Material: Ensenada de Catripe, Bahia de Malaga (Ladri- lleros), Bahia de Buenaventura (La Bocana), Punta Coco, Guapi, Mulatos, Vigia, Tumaco (Isla del Gallo), Isla de Gorgona. Habitat: Sandy beaches and bars from the intertidal zone to 25 m. Size: 57 mm length, 46 mm height. Range: Sonora, México, to northern Peru. Tivela (Tivela) byronensis (Gray, 1838) OLSSON, 1961:267, pl. 44, figs. 3, 6-8. KEEN, 1971:162, fig. 385. Material: Ensenada de Catripe, Bahia de Malaga (Ladri- lleros). Cited by COsEL (1986) from Isla de Gorgona (Gorgonilla). Habitat: Sandy beaches and offshore to 70 m. Size: 29 mm length, 26 mm height. Range: Baja California to northern Peru. Twela (Tivela) hindsu (Hanley, 1834) KEEN, 1971:164, fig. 387. Material: Ensenada de Catripe, Bahia de Malaga (Ladri- lleros). Habitat: Empty shells on sandy beaches. Size: 35 mm length, 31 mm height. Range: West Mexico to Ecuador. Remarks: Some authors consider 7. hindsw a synonym of T. byronensis. Tivela (Tivela) planulata (Broderip & Sowerby, 1830) OLSSON, 1961:269, pl. 44, fig. 5-5a. KEEN, 1971:164, fig. 390. The Veliger, Vol. 34, No. 1 Material: Ensenada de Catripe, Bahia Malaga (Ladrille- ros), Guapi, Mulatos. Habitat: Empty shells on sandy beaches. Size: 47 mm length, 51 mm height. Range: Baja California to Ecuador. Subfamily PITARINAE Pitar (Pitar) consanguineus (C. B. Adams, 1852) OLSSON, 1961:274, pl. 45, fig. 3-3a. KEEN, 1971:168, fig. 398. Material: Isla de Gorgona (Playa Pizarro). Habitat: Sandy subtidal substrate from 1 to 20 m. Size: 25 mm length, 20 mm height. Range: Puerto Guatulco, México, to Isla de Gorgona, Colombia (COSEL, 1986). Pitar (Pitar) elenensis Olsson, 1961 OLssoNn, 1961:275, pl. 45, fig. 1-1b. KEEN, 1971:168, fig. 399. Material: Golfo de Tortugas, Isla de Gorgona (Muelle), Tumaco (Isla del Gallo). Habitat: Sandy beach, empty shells. Size: 27 mm length, 23 mm height. Range: Panama to northern Peru. Pitar (Pitar) helenae Olsson, 1961 OLSSON, 1961:276, pl. 45, fig. 2-2a. KEEN, 1971:170, fig. 401. Material: Isla de Gorgona (Playa Blanca). Habitat: Sandy beach, empty shells Size: 21 mm length, 16 mm height. Range: Gulf of California to Panama. Remarks: This is a new record for the molluscan fauna of Colombian Pacific. COSEL (1986) recorded this spe- cies as P. berry: Keen, 1971, but the specimens from Isla de Gorgona do not have the diagnostic features of this species. Instead, the shape and color match very well the description of P. helenae Olsson, 1961. Pitar (Pitar) fluctuatus (Sowerby, 1851) OLsson, 1961:275, pl. 43, fig. 7-7a; pl. 45, figs. 5, 7. KEEN, 1971:170, fig. 400. Material: Isla de Gorgona (Muelle, Playa Pizarro, Playa Blanca). Habitat: Subtidal sandy bottoms to 15 m; empty shells on intertidal sandy beaches. Size: 62 mm length, 47 mm height. Range: Panama to Ecuador. Pitar (Hypanthosoma) hertleint Olsson, 1961 OLSSON, 1961:276, pl. 45, fig. 6-6a. KEEN, 1971:170, fig. 405. Material: Ensenada de Utria, Isla de Gorgona (Muelle, Gorgonilla). J. R. Cantera K., 1991 Habitat: Sandy-coral beaches, from the intertidal zone to 2 m. Size: 55 mm length, 44 mm height. Range: Panama to northern Peru. Pitar (Hysteroconcha) brevispinosus (Sowerby, 1851) OLSSON, 1961:284, pl. 47, fig. 4-4a. KEEN, 1971:172, fig. 407. Material: Bahia Octavia, Ensenada Catripe, Charambira, Bahia de Malaga (Juanchaco, Ladrilleros), Guapi, Mulatos, Vigia, Tumaco (Isla del Gallo), Isla de Gor- gona (Gorgonilla). Habitat: Empty shells on sandy beaches. Size: 48 mm length, 38 mm height. Range: Gulf of California to Ecuador. Pitar (Hysteroconcha) lupanaria (Lesson, 1830) OLSSON, 1961:283, pl. 47, fig. 1-1c. KEEN, 1971:172, fig. 408. Material: Ensenada de Catripe, Charambira, Bahia de Malaga (Ladrilleros), Punta Coco, Guapi, Mulatos, Vigia, Tumaco (Bocagrande, Isla del Gallo). Habitat: Empty shells on sandy beaches. Size: 59 mm length, 46 mm height. Range: Baja California to northern Peru. Pitar (Hysteroconcha) multispinosus (Sowerby, 1851) OLSSON, 1961:284, pl. 47, fig. 2-2d. KEEN, 1971:172, fig. 409. Material: Bahia de Malaga (Juanchaco, Ladrilleros), Guapi, Mulatos, Vigia, Tumaco (Isla del Gallo), Isla de Gorgona (Gorgonilla). Habitat: Empty shells on sandy beaches. Size: 37 mm length, 30 mm height. Range: Gulf of California to northern Peru. Remarks: This species has a strong resemblance to P. lupanaria. Specimens matching the descriptions of both species have been found on the Pacific coast of Co- lombia. Further work is necessary to demonstrate that these are really different species based on shell and spine sizes and general form and color. Pitar (Hysteroconcha) roseus (Broderip & Sowerby, 1829) OLSSON, 1961:284, pl. 47, fig. 3-3d. KEEN, 1971:172, fig. 410. Material: Bahia de Malaga (Ladrilleros), Mulatos, Vigia, Tumaco (Bocagrande, Isla del Gallo), Isla de Gorgona (Gorgonilla). Habitat: On sandy bottoms, intertidal zone to 15 m; empty shells on rocky shores. Size: 52 mm length, 40 mm height. Range: Gulf of California to northern Peru. Pitar (Lamelliconcha) alternatus (Broderip, 1835) OLSSON, 1961:286, pl. 48, fig. 1-1b. KEEN, 1971:172, fig. 411. Page 81 Material: Isla de Gorgona (Gorgonilla). Cited by OLSSON (1961) from Tumaco (Isla del Gallo) as Lamelliconcha circinata alternatus. Habitat: Empty shells on a sandy coral beach. Size: 43 mm length, 37 mm height. Range: Gulf of California to northern Peru. Pitar (Lamelliconcha) concinnus (Sowerby, 1835) OLSSON, 1961:287, pl. 48, fig. 4-4c. KEEN, 1971:174, fig. 413. Material: Ensenada Catripe, Bahia de Malaga (Ladrille- ros, Los Monos), Punta Coco, Guapi, Mulatos, Vigia. Habitat: Empty shells on sandy beaches. Size: 40 mm length, 31 mm height. Range: Baja California to Paita, Peru, and Galapagos Islands (STRONG & HERTLEIN, 1939). Pitar (Lamelliconcha) paytensis (Orbigny, 1845) OLSSON, 1961:288, pl. 48, fig. 6-6b. KEEN, 1971, fig. 416. Material: Ensenada de Catripe, Guapi, Vigia, Tumaco. Habitat: One empty shell on a sandy beach. Size: 40 mm length, 28 mm height. Range: Gulf of California to Peru. Pitar (Lamelliconcha) tortuosus (Broderip, 1835) OLSSON, 1961:288, pl. 48, fig. 5-5a. KEEN, 1971:174, fig. 417. Material: Ensenada de Catripe, Bahia Buenaventura (Punta Soldado), Guapi, Mulatos, Tumaco (Isla del Gallo). Habitat: Empty shells on sandy beaches. Size: 42 mm length, 35 mm height. Range: Guaymas, Mexico, to Northern Peru. Remarks: Some authors consider it a synonym of P. con- cinnus (Sowerby, 1835). Pitar (Lamelliconcha) unicolor (Sowerby, 1835) OLSSON, 1961:289, p. 40, fig. 3, pl. 49, fig. 4-4a. KEEN, 1971:174, fig. 418. Material: Punta Ardita, Bahia Octavia, Ensenada Catripe, Bahia Malaga (Curichichi, Ladrilleros), Bahia Bue- naventura (Punta Soldado). Habitat: Empty shells from sandy beaches. Size: 47 mm length, 39 mm height. Range: Gulf of California to Ecuador. Pitar (Lamelliconcha) vinaceus (Olsson, 1961) OLSSON, 1961:287, pl. 48, fig. 2-2b. KEEN, 1971:174, fig. 419. Material: Bahia de Malaga (Juanchaco). Cited by OLSSON (1961) as Lamelliconcha circinata vinacea from Tu- maco (Isla del Gallo). Habitat: Empty shells on sandy beaches. Page 82 Size: 34 mm length, 29 mm height. Range: México to Ecuador. Pitar (Pitarella) catharius (Dall, 1902) OLsson, 1961:279, pl. 40, fig. 2; pl. 49, fig. 5-5a. KEEN, 1971:176, fig. 421. Material: Bahia Otavia, Ensenada Catripe, Isla de Gor- gona. Habitat: Empty shells from sandy beaches. Size: 47 mm length, 31 mm height. Range: Baja California to northern Peru. Macrocallista aurantiaca (Sowerby, 1835) OLSSON, 1961:273, pl. 46, fig. 1-1c. KEEN, 1971:176, fig. 424. Material: Ensenada de Utria, Bahia de Malaga (Los Ne- gros), Isla de Gorgona (Playa Pizarro). Habitat: Subtidal sandy bottoms, 1 to 15 m. Size: 105 mm length, 80 mm height. Range: Gulf of California to northern Pert and Galapagos Islands (STRONG & HERTLEIN, 1939). Subfamily DOSINIINAE Dosinia dunkeri (Philippi, 1844) OLsson, 1961:261, pl. 42, fig. 3-3b. KEEN, 1971:178, fig. 426. Material: Isla de Gorgona (Muelle). Habitat: Empty shells on sandy beaches. Size: 44 mm length, 4Z mm height. Range: Gulf of California to Zorritos, Peru, and Gala- pagos Islands (STRONG & HERTLEIN, 1939). Dosinia ponderosa (Gray, 1838) OLSSON, 1961:260, pl. 40, fig. 5; pl. 42, fig. 1-1c; pl. 43, fig. 1. KEEN, 1971:178, fig. 427. Material: Golfo de Tortugas, Isla de Gorgona (Gorgoni- lla), Tumaco (Isla del Gallo). Cited by CosEL (1986) from Isla de Gorgona (Muelle, Playa Blanca). Habitat: Empty shells on sandy beaches. Size: 34 mm length, 36 mm height. Range: Gulf of California to Paita, Peru. Subfamily CYCLININAE Cyclinella singleyi Dall, 1902 OLsson, 1961:265, pl. 43, fig. 5-5a. KEEN, 1971:180, fig. 432. Material: Tumaco (Isla del Gallo). Cited by OLSSON (1961) from the same locality. Habitat: One empty shell on a rocky shore. Size: 32 mm length, 29 mm height. Range: Baja California to Perd. KEEN (1971) cited this species from Baja California to Panama. The Veliger, Vol. 34, No. 1 Subfamily CHIONINAE Chione (Chione) subtmbricata (Sowerby, 1835) OLSSON, 1961:295, pl. 55, fig. 4-4b. KEEN, 1971:185, fig. 443. Material: Isla de Gorgona (Gorgonilla). Habitat: Empty shells on sandy beaches to 9 m. Size: 31 mm length, 32 mm height. Range: Gulf of California to Peru. Chione (Chionopsis) amathusia (Philippi, 1844) OLSSON, 1961:299, pl. 41, fig. 7, pl. 51, fig. 1-1a, pl. 84, fig. 2. KEEN, 1971:186, fig. 448. Material: Ensenada Catripe, Bahia Malaga (Juanchaco, Ladrilleros), Bahia de Buenaventura (Punta Soldado, La Bocana), Punta Coco, Guapi, Mulatos, Vigia. Habitat: Empty shells on sandy beaches. Size: 35 mm length, 40 mm height. Range: Gulf of California to Mancora, Peru. Chione (Chionopsis) olssoni (Fischer-Piette, 1969) KEEN, 1971:188, fig. 453. Material: No material was examined. Cited by COSEL (1986) from Isla de Gorgona. Habitat: One empty shell on a sandy-rocky beach (COSEL, 1986). Size: Unknown. Range: Isla de Gorgona to Ecuador. Chione (Chionopsis) ornatissima (Broderip, 1835) OLsson, 1961:300, pl. 51, fig. 3-3a. KEEN, 1971:188, fig. 454. Material: Charambira, Bahia Malaga (Ladrilleros), Ba- hia de Buenaventura (Punta Soldado), Guapi, Tu- maco (Bocagrande). Habitat: Empty shells on sandy beaches; live in 20-25 m on mud bottoms. Size: 47 mm length, 45 mm height. Range: Panama to Ecuador. Chione (Chionopsis) pulicaria (Broderip, 1835) OLSSON, 1961:302, pl. 52, figs. 4-4a, 5-5a. KEEN, 1971:188, fig. 455. Material: Isla de Gorgona. Cited from Tumaco by OLSSON (1961). Habitat: One empty valve on a sandy beach. Size: 11 mm length, 9 mm height. Range: Gulf of California to Tumaco, Colombia. Remarks: Cited by COsEL (1986) as Chione guatulcoensis Hertlein & Strong, 1948, but his figure suggests that it probably is C. pulicaria. Chione (lliochione) subrugosa (Wood, 1828) OLsson, 1961:298, pl. 51, fig. 5-5a. KEEN, 1971:190, fig. 457. J. R. Cantera K., 1991 Material: Bahia de Malaga (La Plata, Punta la Muerte, Playa Chucheros), Bahia de Buenaventura (Isla del Cangrejo), Guapi, Mulatos, Vigia, Tumaco (Isla del Gallo). Cited by CosEL (1986) from Isla de Gorgona. Habitat: Intertidal mud flats with gravel, near to mangrove areas. Used as food in some places, mainly in Bahia Malaga. Size: 39 mm length, 30 mm height. Range: Gulf of California to Pert and Galapagos Islands (STRONG & HERTLEIN, 1939). Chione (Lirophora) kelletti (Hinds, 1845) OLSSON, 1961:296, pl. 41, fig. 5; pl. 51, fig. 4-4a. KEEN, 1971:190, fig. 459. Material: Isla de Gorgona. Habitat: Muddy zones offshore in 30 m. Size: 60 mm length, 52 mm height. Range: Gulf of California to Peru. Chione (Lirophora) mariae (Orbigny, 1846) OLsson, 1961:296, pl. 49, figs. 2, 8-8a. KEEN, 1971:190, fig. 460. Material: Isla de Gorgona. Cited by OLsson (1961) from Tumaco (Isla del Gallo). Habitat: Empty shells on sandy beaches. Size: 20 mm length, 16 mm height. Range: Gulf of California to Guayaquil, Ecuador. Protothaca (Antichione) bel: (Olsson, 1961) OLssoNn, 1961:310, pl. 50, figs. 1-1a, 4. KEEN, 1971:193, fig. 465. Material: Golfo de Tortugas, Guapi, Tumaco (Isla del Gallo). Habitat: On intertidal muddy rocky flats. Size: 39 mm length, 35 mm height. Range: Panama to Ecuador. Protothaca (Colonche) ecuadoriana (Olsson, 1961) OLsson, 1961:311, pl. 41, fig. 2; pl. 55, fig. 5. KEEN, 1971:193, fig. 466. Material: Bahia Malaga (Isla El Aguante), Tumaco (Isla del Gallo). Habitat: Mud flats in shallow water. Size: 38 mm length, 31 mm height. Range: Colombia to Ecuador. Protothaca (Leukoma) asperrima (Sowerby, 1835) OLsson, 1961:307, pl. 53, fig. 3-3a; pl. 54, fig. 6. KEEN, 1971:193, fig. 467. Material: Bahia de Malaga (La Muerte, La Plata), Bahia de Buenaventura (Punta Soldado), Guapi, Tumaco. Habitat: In mud between the roots of mangrove trees. Size: 42 mm length, 35 mm height. Range: Gulf of California to Peru. Page 83 Protothaca (Leukoma) metodon (Pilsbry & Lowe, 1932) OLsson, 1961:308, pl. 55, fig. 3-3a. KEEN, 1971:195, fig. 469. Material: Bahia Malaga (La Plata), Bahia de Buenaven- tura (Punta Soldado), Tumaco (Bocagrande). Habitat: Empty shells on sandy beaches. Size: 32 mm length, 29 mm height. Range: Guaymas, Mexico, to Tumaco, Colombia. This is a new record for the Pacific coast of Colombia. Protothaca (Leukoma) zorritensis (Olsson, 1961) OLSSON, 1961:308, pl. 53, fig. 5-5a; pl. 55, fig. 6. KEEN, 1971:195, fig. 471. Material: Tumaco. Habitat: Intertidal gravel-mud flats. Size: 27 mm length, 22 mm height. Range: Colombia (Tumaco) to Zorritos and Paita, Pert. This is a new record for the Pacific coast of Colombia. Protothaca (Tropithaca) grata (Say, 1831) OLSSON, 1961:305, pl. 53, figs. 2-2b, 7. KEEN, 1971:195, fig. 473. Material: Bahia Malaga (Isla de Curichichi), Bahia Bue- naventura (Punta Soldado). Habitat: Mud flats near mangrove swamps. Size: 40 mm length, 32 mm height. Range: Gulf of California to Chile. CONCLUSION The shallow-water and intertidal venerid bivalves from the Pacific coast of Colombia have been poorly studied, although OLSSON (1961) and KEEN (1971) gave some data for this country. The 40 species included in this paper demonstrate that the Pacific coast of Colombia has a diverse fauna, determined mainly by the great variety of habitats, such as mud flats, mangrove swamps, rocky cliffs, rocky shores, sandy beaches, and coral reefs. Only three species cited by KEEN (1971) as occurring between a locality north of Colombia and Ecuador or Pert were not found in this study—Cyclinella jadisi Olsson, 1961; Irus (Paphonotia) ellipticus Sowerby, 1834; and Transennella modesta (Sow- erby, 1835). The greatest number of species found on the Pacific coast of Colombia were associated with soft bottoms, main- ly sandy beaches and mud flats. Most species were collected as empty shells on sandy beaches (55.0%). Most of the species collected alive are associated with sandy subtidal bottoms (17.5%) and muddy substrates in or near man- grove swamps (12.5%). The other two abundant substrates have three species (7.5%) each. The venerids of the Pacific coast of Colombia are mainly characteristic of the Panamic Province, having a geograph- ic distribution between the southern Gulf of California (64.8%) and northern Peru (57.8%). México is the north- ern limit for 80% of species and Panama is for 10.8%; Page 84 The Veliger, Vol. 34, No. 1 26.2% of species have Ecuador as a southern limit. Four taxa—Pitar consanguineus, Pitar elenae, Chione pulicaria, and Protothaca metodon—have a Colombian locality as a southern limit, and three—Chione olssoni, Protothaca ecu- adoriana, and Protothaca zorritiensis—have Colombia as a northern limit. Only one species, Protothaca grata, reaches Chile. In spite of relatively abundant malacological fauna of the Indo-West Pacific (EMERSON, 1967, 1978), no venerid from this area was found on the Pacific coast of Colombia. Only few species of this family inhabit coral environments, the main biotope of Central Pacific islands, and there are no records of long-survival veliger (teleplanic) larvae in this family that could facilitate their reaching different islands of the Central Pacific Ocean (SCHELTEMA, 1986). The alternative modes of long distance dispersal—adult mi- gration, transport by rafting, and human activities—are not possible because of the particular life conditions of Veneridae and the areas that they inhabit (sandy and muddy beaches). LITERATURE CITED CANTERA, J. R., E. A. Rusio, F. J. BORRERO, R. CONTRERAS, F. Zapata & E. BuTTKus. 1979. Taxonomia y distri- bucion de los moluscos litorales de la Isla de Gorgona, Co- lombia. Pp. 141-168. Jn: H. Prahl et al. (eds.), Gorgona. Universidad de los Andes, Departamento de Biologia: Bo- gota. CosEL, R. VON. 1986. Moluscos marinos de la Isla de Gorgona (Costa del Pacifico Colombiano). Anales Instituto de Inves- tigaciones Marinas de Punta Betin, Santa Marta 14:175- 257. EMERSON, W. K. 1967. Indo-Pacific faunal elements in the tropical eastern Pacific, with special reference to the mol- lusks. Venus 25(3,4):85-93. EMERSON, W. K. 1978. Mollusks with Indo-Pacific faunal affinities in the eastern Pacific Ocean. The Nautilus 92(2): 91-96. ESCALLON, S. & J. R. CANTERA. 1989. Moluscos marinos de la Bahia de Malaga, Costa Pacifica Colombiana. I. Pele- cypoda. Boletin cientifico de la Universidad de la Salle 3(2): 159-178. HERTLEIN, L. G. & A. M. STRONG. 1955. Marine mollusks collected during the “ASKOY” Expedition to Panama, Co- lombia and Ecuador in 1941. Bulletin of the American Mu- seum of Natural History New York 107(2):165-317. KEEN, M. A. 1971. Seashells of Tropical West America. Ma- rine mollusks from Baja California to Peru. 2nd ed. Stanford University Press: Stanford, California. 1064 pp. Oxsson, A. A. 1961. Mollusks of the tropical eastern Pacific, particularly from the southern half of the Panamic-Pacific faunal province (Panama to Peru). Panamic Pacific Pele- cypoda. Paleontological Research Institution: Ithaca, New York. 573 pp. PRAHL, H. von. 1986. Notas sobre la zoogeografia de corales, crustaceos, moluscos y peces. Pp. 90-127. Jn: H. von Prahl & M. Alberico (eds.), Isla de Gorgona. Banco Popular and Universidad del Valle. SCHELTEMA, R.S. 1986. On the dispersal and planktonic larvae of benthic invertebrates: an eclectic overview and summary of problems. Bulletin of Marine Sciences 39(2):290-322. STRONG, A. M. & L. G. HERTLEIN. 1939. Marine mollusks from Panama collected by the Allan Hancock Expedition to the Galapagos Islands, 1931-1932. Allan Hancock Pacific Expeditions 2(12):177-245. The Veliger 34(1):85-87 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 First Record of the Indo-Pacific Gastropod C'ypraea caputserpentis (Linnaeus, 1758) at Isla de Gorgona, Colombia JAIME R. CANTERA K. Universidad del Valle, Departamento de Biologia, A.A. 25360, Cali, Colombia Abstract. "The present paper records an extension of the known geographical range for Cypraea (Erosaria) caputserpentis. This species is of wide western Indo-Pacific distribution in eastern and southern Africa, eastern and southern Asia, Australia, the islands of Polynesia, and Hawaii. The only previous records in the eastern Pacific are from Clipperton Island and Cocos Island. The new record is based on a single empty shell collected in November 1988 at Isla de Gorgona, 30 km off the mainland of Colombia and about 2300 km southeast of Clipperton Island. INTRODUCTION Several Indo-Pacific species of mollusks, mainly gastropods of the families Architectonicidae (ROBERTSON, 1976, 1980), Conidae (EMERSON, 1978), Coralliophilidae (EMERSON, 1978; CANTERA et al., 1979), Mitridae (COSEL, 1977) and Cypraeidae, have been recorded from the eastern Pacific. The most commonly reported Indo-Pacific cypraeid in eastern Pacific waters is Cypraea teres Gmelin, 1791, which has been found at Clipperton Island (HERTLEIN & EMERSON, 1953; HERTLEIN & ALLISON, 1960; EMERSON, 1967); the Galapagos Islands (EMERSON & OLD, 1965, 1968), Bahia Honda, Panama (Bakus, 1968), Isla Mal- pelo (BIRKELAND et al., 1975) and Isla de Gorgona (COSEL, 1986; CANTERA, 1986). BURGESS (1985) considers some of the citations of C. teres in the eastern Pacific to be referable to C. alisonae Burgess, 1983. Cypraea talpa Linnaeus, 1758, has been recorded from Cocos Island (SHASKY, 1983) and western Panama (EMERSON, 1983). The other species in the eastern Pacific area are cited by KEEN (1971): Cypraea depressa Gray, 1824; C. maculifera Schilder, 1932; C. scurra indica Gmelin, 1791; C. helvola Linnaeus, 1758; C. schilder- orum (Iredale, 1939); C. vitellus Linnaeus, 1758; and C. moneta Linnaeus, 1758. All of these species are found on Clipperton Island. Cypraea moneta is also known from the Galapagos Is- lands (HERTLEIN, 1937; FINET, 1987) and Cocos Island (Montoya, 1983). Cypraea rashleighana Melvill, 1888, has been recorded only from Cocos Island (CATE, 1969) but SHASKy (1989) considers it as C. alisonae Burgess, 1983. Cypraea caputserpentis was recorded previously from Clipperton Island (HERTLEIN & ALLISON, 1960) and Co- cos island (SHASKY, 1989). The present paper records an empty shell of the latter species from a sandy gravel beach on Isla de Gorgona, Colombian Pacific, the first record of this taxon from West American borderland. Gorgona (2°58'N, 78°11'W), a volcanic island located 30 km from the Pacific coast of Colombia, was attached to the continent by the Baudo “cordillera” which was submerged in the Miocene (HAFFER, 1970). The coast of Gorgona has rocky cliffs, rocky shores, and sandy beaches, and in some regions there are coral reefs of irregular sizes in shallow water to 15 m depth. Southward is Gorgonilla, a smaller island separated from Gorgona by the 700-m wide Tasca Strait. THE SPECIMEN FROM GORGONA Description The only specimen of Cypraea caputserpentis from Gor- gona (Figure 1) does not differ significantly from the spec- imen illustrated by BURGESS (1985). The specimen from Gorgona has 14 teeth on the inner lip and 16 on the outer lip. The color is typical of this species: a background of chocolate brown on the marginal zones, and spots varying in size and form, forming a reticulate pattern, on the central zone. The base is chocolate brown on the periphery, with white or creamy callus near the aperture. The region of teeth is white separated by interspaces of chocolate brown. The shell interior is brown. The dimensions are 33 mm Page 86 The Veliger, Vol. 34, No. 1 Figure 1 Cypraea (Erosaria) caputserpentis (Linnaeus, 1758) collected at Isla de Gorgona (length, 33 mm; width, 24.5 mm; height, 22 mm). length, 24.5 mm width, and 22 mm height. The specimen is deposited in the malacological collection of the University of Valle, Cali, Colombia (No. 88098). Habitat This record is based on a dead, but well preserved shell collected at 2-m depth between the islands of Gorgona and Gorgonilla on sandy gravel, near coral colonies in Novem- ber 1988. The principal corals in the zone are species of Pocillopora, Pavona, and Porites. Geographic Distribution The species Cypraea caputserpentis has a wide distri- bution in the Indo-Pacific and in some localities of the eastern Pacific (BURGESS, 1985). Furthermore some rec- ords of this species by HIDALGO (1906) were not cited by BuRGESS (1985): southern Africa (El Cabo, Natal); eastern Africa (Reunion, Almirantes, Seychelles, Egypt); southern Asia (Laccadives, India, Andaman, Nicobar, Malacca); and eastern Asia (Hainan, Taiwan, China, Marianas, Carolinas). The previous nearest records to Isla de Gor- gona are of HERTLEIN & ALLISON (1960), who recorded C. caputserpentis from Clipperton Island, and of SHASKY (1989) who recorded it from Cocos Island. DISCUSSION anp CONCLUSIONS Although based on a single shell, this paper presents a new record of Cypraea caputserpentis from the eastern Pa- cific, confirming earlier records of this species from Clip- perton Island and Cocos Island. However, little is known about the possible establishment of viable populations of C. caputserpentis in the eastern Pacific, and it is possible that the shell found at Gorgona was transported as a veliger from Polynesia, from other islands of the central Pacific, or from an established population on eastern Pacific islands (Cocos and Clipperton). These islands could serve as “‘mi- gratory bridges” for some Indo-Pacific species that have teleplanic larvae, as is suggested by SCHELTEMA (1986) for other families of prosobranch gastropods such as Ar- chitectonicidae, Cymatiidae, Bursidae, and Coralliophili- dae. ACKNOWLEDGMENTS I thank Eugene V. Coan for advice and support in all aspects of my malacological work, and for his suggestions and corrections to this manuscript. LITERATURE CITED Bakus, G. J. 1968. Quantitative studies on cowries (Cypraei- dae) of the Allan Hancock Foundation Collections. The Ve- liger 11(2):93-96. J. R. Cantera K., 1991 BIRKELAND, C., D. L. MEYER, J. P. STAMES & C. L. BUFORD. 1975. Subtidal communities of Malpelo Island. Smithson- ian Contributions to Zoology 176:55-68. BurGEss, C. M. 1985. Cowries of the world. Gordon Verhoef Seacomber Publications: Capetown, South Africa. 289 pp. CANTERA, J. R. 1986. Un nuevo registro de Cypraea teres Gme- lin, 1791, gasteropodo indopacifico, en la isla de Gorgona, Colombia. Actualidades Biologicas 15(55):23-26. CANTERA, J. R., E. A. Rusio, F. BORRERO, R. CONTRERAS, F. ZAPATA & E. BuTTKuS. 1979. Taxonomia y distribuci6én de los moluscos litorales de la isla Gorgona. Pp. 141-167. In: Prahl H. von, Guhl F. & Grohl M. (eds.), Gorgona. Universidad de los Andes: Bogota (Colombia). 279 pp. CaTE, C. N. 1969. The eastern Pacific Cowries. The Veliger 12(1):103-119. CosEL, R. von. 1977. First record of Mitra mitra (Linnaeus, 1758) (Gasteropoda: Prosobranchia) on the Pacific coast of Colombia, South America. The Veliger 19(4):422-424. CosEL, R. VON. 1986. Moluscos marinos de la Isla de Gorgona (costa del Pacifico Colombiano). Anales del Instituto de In- vestigaciones Marinas de Punta de Betin, Sta. Marta 14: 175-257. EMERSON, W. K. 1967. Indo-Pacific faunal elements in the tropical eastern Pacific, with special reference to the mol- lusks. Venus 25(3, 4):85-93. EMERSON, W. K. 1978. Mollusks with Indo-Pacific faunal affinities in the eastern Pacific Ocean. The Nautilus 92(2): 91-96. EMERSON, W. K. 1983. New records of prosobranch gastropods from Pacific Panama. The Nautilus 97(4):119-123. EMERSON, W. K. & W. E. OLD. 1965. New molluscan records for the Galapagos Islands. The Nautilus 78(4):116-120. EMERSON, W. K. & W. E. OLD. 1968. An additional record for Cypraea teres in the Galapagos Islands. The Veliger 11(2):98-100. Page 87 FINET, Y. 1987. Living Cypraea moneta L. in the Galapagos Islands. La Conchigilia 19(222-223):22-24. HaFFER, J. 1970. Geologic climatic history and zoogeographic significance of the Uraba region in Northwestern Colombia. Caldasia 10:603-636. HERTLEIN, L. G. 1937. A note on some species of marine mollusks occurring in both Polynesia and the western Amer- ica. Proceedings of the American Philosophical Society 78: 303-312. HERTLEIN, L. G. & E. C. ALLISON. 1960. Species of the genus Cypraea from Clipperton Island. The Veliger 2(4):94-95. HERTLEIN, L. G. & W. K. EMERSON. 1953. Mollusks from Clipperton Island (eastern Pacific) with the description of a new species of gastropod. Transactions of the San Diego Society of Natural History 11(3):345-364. HIDALGO, J. G. 1906. Obras malacologicas: monografia de las especies recientes del genero Cypraea. Imprenta Gaceta de Madrid. xv + 588 pp. KEEN, A.M. 1971. Sea shells of tropical west America. Marine mollusks from Baja California to Peru. 2nd ed. Stanford University Press: Stanford, Calif. xvi + 1064 pp. Montoya, M. 1983. Los moluscos marinos de la isla del Coco, Costa Rica. I. Lista Anotada de Especies. Brenesia 21:325- 353. ROBERTSON, R. 1976. Heliacus trochoides: an Indo-west Pacific architectonicid newly found in the eastern Pacific (mainland Ecuador). The Veliger 19(1):13-18. ROBERTSON, R. 1980. Philippia (Psilaxis) radiata: another Indo- west Pacific architectonicid newly found in the eastern Pa- cific (Colombia). The Veliger 22(2):191-193. SHasky, D. R. 1983. New records of Indo-Pacific Mollusca from Cocos Island, Costa Rica. The Nautilus 97(4):144- 145. Suasky, D. R. 1989. My last seven years at Cocos Island. The Festivus 21(8):72-75. The Veliger 34(1):88-90 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 A New Epitoniid Species from the Pacific Coast of the Kui Peninsula, Japan by TAISEI NAKAYAMA Department of Chemistry, University of California, Berkeley, California 94720, USA Abstract. Graciliscala koshimagani sp. nov. is described. It is parasitic on an undetermined Epi- zoanthus species, which occurs on the carapace of the crab Leotomithrax edwardsi (de Haan, 1839). The new species appears to be morphologically close to Graciliscala ishimotoi Masahito & Habe, 1976, or Graciliscala rimbogai Masahito & Habe, 1976, but differs in having a more inflated body whorl and more axial costae. INTRODUCTION Several minute epitoniids were collected in 1988 from an undetermined species of Epizoanthus attached to the car- apace of the crab Leotomithrax edwardsi (de Haan, 1839). The crabs were gathered with a lobster gill net set on the seabed off Kirimezaki, Kii Peninsula, Wakayama Japan. These epitoniids are classified in the genus Graciliscala by their conchological characters (REEVE, 1874; DE Boury, 1909). MASAHITO & HABE (1976) reported two Gracilis- cala species collected from the same region, off Kii Pen- insula, Japan. Furthermore, according to their description, these two Graciliscala species are also parasitic on minute sea anemones of the genus Epizoanthus. However, con- chological characters indicate that the specimens collected in 1988 represent a new species of the genus Graciliscala. TAXONOMY Family Epitoniidae Roding, 1798 Genus Graciliscala de Boury, 1909 Graciliscala koshimagani Nakayama, sp. nov. (Figures 1-6, 10) Description: Shell rather small, thin, milky white, py- ramidally ovate, becoming attenuate toward the small apex. Spire elevated pyramidally with 8 or 9 whorls. Surface with 12 or 13 thin axial costae, interspaces between each two costae crossed by 20-25 very fine spiral threads. Pro- toconch of 4 smooth, polished whorls. Teleoconch whorls 4 or 5 in number, well rounded with deep suture and slightly separated by riblets. Body whorl width about one- half of shell height and well rounded at the periphery. Aperture ovate, but not angular, rounded, thickened and reflexed at the last costa. Umbilicus closed. Operculum ovate, thin light yellowish brown and paucispiral. Type deposition and measurements: Type specimens are deposited in the University of California Museum of Pa- leontology. Holotype, height 5.0 mm and width 3.0 mm (UCMP Type No. 38641); paratype 1, height 6.0 mm and width 3.2 mm (UCMP Type No. 38642); paratype 2, height 3.5 mm and width 2.1 mm (UCMP Type No. 38643). Explanation of Figures 1 to 9 Figures 1 and 2. Graciliscala koshimagani sp. nov., holotype, off Kii Peninsula, Japan, 34°00'N, 134°48’E, 90 m deep (UCMP 38641), 5.0 mm. Figures 3-5. Graciliscala koshimagani, paratype 2 (UCMP 38643), 3.5 mm. Figure 6. Electron micrographs of protoconch of Graciliscala koshimagani, scale line = 64.5 um. Figures 7 and 8. Graciliscala rmbogai Masahito & Habe, 1976, off Kii Peninsula, Japan, 7.0 mm. Figure 9. Electron micrograph of protoconch of Graciliscala rimbogai, scale line = 106 um. Page 89 T. Nakayama, 1991 Page 90 The Veliger, Vol. 34, No. 1 Explanation of Figures 10 and 11 Figure 10. Graciliscala koshimagani, parasitic on the cnidarian Epizoanthus sp. attached to the carapace of the crab Leotomithrax edwards. Figure 11. Leotomithrax edwardsi (de Haan, 1839), host of the Epizoanthus sp., 30 cm. Type locality: Offshore Kirimezaki, Kii Peninsula, Mina- be Wakayama, Japan (34°00'N, 134°48’E) about 90-120 m deep. Etymology: koshimagani is derived from the Japanese name for Leotomithrax edwardst. REMARKS This new species is parasitic on an undetermined species of Epizoanthus attached to the carapace of the crab Leo- tomithrax edwardsi (de Haan, 1839). UTsUMI (1976) showed that some Actiniaria species also occur on L. edwardsi, but this new species is not associated with Actiniaria. Although Leotomithrax edwards: may have several tiny zoanthids on its carapace, the new species is found only on the Epi- zoanthus species (Figures 3, 10). From a conchological point of view, this new species is similar to Graciliscala rmbogai Masahito & Habe, 1976, but differs by having a more inflated body whorl. The shell height—width ratio of the new species is 1.5-1.9, while in G. rimbogat it is 2.2-2.5. Moreover, the new species has 12 or 13 costae where G. rmbogaz has only 10 or 11. The new species also resembles Graciliscala ishimotoi Masahito & Habe, 1976, but G. koshimagani sp. nov. can be easily distinguished by its thin costae and pyramidal shape. Most species of Graciliscala occur on species of Epr- zoanthus but the primary associations of G. koshimagani sp. nov. differ from those of other Graciliscala species. Graciliscala ishimotoi is parasitic on Epizoanthus ramosus Cargren, which is attached to the surface of dead gastro- pods such as Pterynotus pinnatus (Wood, 1815); G. rxmbogaz is parasitic on an undetermined species of Epizoanthus attached to the surface of Guildfordia triumphans Philippi, 1841. ACKNOWLEDGMENTS I am very grateful to Messers Torao Yamamoto and Ma- nabi Manabe who gave me a chance to write this paper. Also I have to note special thanks to Messers Hirokuni Noda and Kouichi Takenouchi who took the photos used in Figures 10 and 11, respectively. I also thank Dr. David Lindberg who was kind enough to review an early draft of this manuscript. LITERATURE CITED DE Boury, E. 1909. Catalogue des sous-genres de Scalidae. Journal de Conchyliologie 57:255-258. MasaHITO & T. HaBE. 1976. Systematic study of Japanese Epitoniidae (III). Bulletin of the National Science Museum, Series A (Zoology) 2(3):169-174. REEVE, L. A. 1874. Conchologia Iconica, 19, pls. 1-16. Sca- laria: London. UrsuMI, F. 1976. Coloured Illustrations of Seashore Animals of Japan. Hoikusya: Osaka. 166 pp. The Veliger 34(1):91-96 (January 2, 1991) THE VELIGER © CMS, Inc., 1991 NOTES, INFORMATION & NEWS Possible Antagonistic Behavior by Pteraeolidia ianthina (Nudibranchia: Aeolidoidea) by Julie G. Marshall and Alan T. Marshall Borchardt Library and Department of Zoology, La Trobe University, Bundoora, Melbourne, Victoria, Australia 3083 In The Veliger of 3 April 1989, Dr. Richard Willan reported that he had witnessed antagonistic behavior by Pteraeolidia ianthina (Angas) (WILLAN, 1989). On 28 Jan- uary 1990, we witnessed a similar type of behavior whilst diving at a depth of 12 m at the diving location known as Coral Grotto off Heron Reef in Queensland, Australia. We observed three adult (approximately 50 mm extended crawling length) Pteraeolidia ianthina. Two were passive but the third animal was continually flailing the anterior half of its body towards one of the other animals. On closer observation this behavior seemed to be triggered when the agitated animal came in contact with a mucous trail left by one of the other animals. This mucous trail was dis- tinctive in that grains of sand were stuck to it. The passive animal continued to move slowly in one direction during the encounter and showed no response to the activity of the other. Although each lunge brought the active Pteraeo- lidia close to the passive animal, as far as we could see they at no time made actual contact. The third Pteraeolidia did not move throughout the encounter. After about five minutes the active Pteraeolidia moved away and neither of the other animals tried to follow it. This behavior might not necessarily be antagonistic. LONGLEY & LONGLEY (1981) described similar behavior in Hermissenda crassicornis but as a preliminary to mating. We may have observed a situation in which one animal was prepared to mate but the other animal was uninter- ested. A response to mucous trails is not unknown to opis- thobranch mollusks: the cephalaspidean Navanax inermis detects prey by mucous trail contact (PAINE, 1963) and also responds to alarm pheromones in mucous trails of the same species (SLEEPER et al., 1980). We should like to thank Robert Burn for his comments and for drawing our attention to the paper by Longley and Longley. Literature Cited LONGLEY, R. D. & A. J. LONGLEY. 1981. Hermuissenda: ago- nistic or mating behavior? The Veliger 24(3):230-231. PAINE, R. T. 1963. Food recognition and predation on opis- thobranchs by Navanax inermis. The Veliger 6(1):1-9. SLEEPER, H. L., V. J. PAUL & W. FENIcAL. 1980. Alarm pheromones from the marine opisthobranch Navanax iner- mis. Journal of Chemical Ecology 6:57-70. WILLAN, R. C. 1989. Field observations on feeding and an- tagonistic behavior by Pteraeolidia ianthina (Nudibranchia: Aeolidoidea). The Veliger 32(2):228-229. Notes on the Distribution, Taxonomy, and Natural History of Some North Pacific Chitons (Mollusca: Polyplacophora) by Roger N. Clark! Field Associate in Malacology, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA During the past seven years of investigations of the chiton fauna of the North Pacific, several distribution re- cords have been noted. These records are reported here along with taxonomic and ecological notes. Voucher specimens for most of the distribution records have been deposited in the Los Angeles County Museum of Natural History (LACM). Other voucher specimens are in the Royal British Columbia Museum (RBCM), Victoria, British Columbia, Canada, and the California Academy of Sciences (CAS), San Francisco, California. Other abbreviations used in the text are as follows: United States National Museum of Natural History (USNM) Washington, D.C.; Santa Barbara Museum of Natural History (SBMNH), Santa Barbara, California; Zoological Institute Academy of Sciences (ZIAS), Len- ingrad, USSR; and the private collection of the author (RNC). LEPIDOPLEURIDAE Hanleyella asiatica Sirenko, 1973 Previous known distribution: Bering Sea (Providence Bay and Anadyr Bay, NE Siberia) to the Kurile Islands (Para- mushir, Onekotan, Simoshir, and Urup islands), USSR (SIRENKO, 1973), 10-130 m on rocks. New records: Six specimens (RNC), 3.5-6.0 mm long, Be- ring Sea, N of Umnak Island, Aleutian Islands, Alaska (52°50.71'N, 168°22.56'W), 198-258 m, on cobbles. Col- lected by RNC, 3 June 1985. Four specimens (one LACM 141148), 5.0-5.5 mm long, Gulf of Alaska, W of Dall Island, extreme SE Alaska (55°00.01'N, 133°57.47'W), 252 m on mud/gravel bottom. Collected by Rae Baxter, 28 August 1987. Remarks: In the Aleutians, Hanleyella asiatica was taken ' Mailing address: 549 Torrey Street, Klamath Falls, Oregon 97601, USA. Page 92 on large cobbles along with Leptochiton alveolus (Loven, 1846) and Placiphorella pacifica Berry, 1919. The new records extend the known range about 4000 km to the east. LEPIDOCHITONIDAE Lepidochitona berryana Eernisse, 1986 Previous known distribution: Pigeon Point, San Mateo County, California, to Palos Verdes, Los Angeles County, California (EERNISSE, 1986), intertidal and shallow sub- tidal. New records: Thirty-two specimens (LACM 66-2), 5.0- 21.5 mm long, Camalu, Baja California Norte, Mexico (30°50’N, 116°5'W), intertidal on rock ledges and boulders. Collected by James H. McLean and P. Oringer, 5-6 Jan- uary 1966. Seven specimens (RNC), 12.0-16.5 mm long, Punta Banda, Baja California Norte, Mexico (31°34'N, 116°40’W), intertidal on rocks. Collected by RNC, A. Todd Moore, and David Forrester, 26 January 1982. One specimen (LACM 68-12), 6.0 mm long, Bahia Guasimas, near Guaymas, Sonora, Mexico (27°59'N, 110°54’W), 25 m on rock. Collected by James H. McLean. Remarks: The new records extend the known range about 440 km to the south on the Pacific coast, and into the Gulf of California. Tonicella insignis (Reeve, 1847) Previous known distribution: Dutch Harbor, Unalaska Is- land, Aleutian Islands, Alaska (BAXTER, 1987) to Wash- ington State (RICE, 1972), intertidal to 52 m. New records: One specimen (RNC), 22.0 mm long, Simp- sons Reef, off Cape Arago, Coos County, Oregon (43°18.30'N, 124°25.30'W), 30 m on rock face. Collected by RNC, 7 July 1984. Two specimens (one LACM 141152) 6.7 and 17.0 mm long, Orford Reef, Curry County, Oregon (42°46'N, 124°36'W), 20 m on rock ledge. Collected by RNC, 11 March 1984. Four specimens (RNC) 18-26 mm long, Blanco Reef, Curry County, Oregon (42°50'N, 124°35’W), 30-34 m on rock ledges and cobbles. Collected by RNC, 15 March 1989. Remarks: Specimens from Blanco Reef were taken along with other, somewhat scarce chitons, Mopalia phorminx Berry, 1919, and Lepidozona scabricostata (Carpenter, 1864). The new records extend the known range 650 km to the south. Dendrochiton semilirata Berry, 1927 Previous known distribution: Departure Bay, Vancouver Island, British Columbia, Canada to Pyramid Cove, San Clemente Island, California (FERREIRA, 1982), 38-141 m. New record: Forty-three specimens (five of them LACM The Veliger, Vol. 34, No. 1 144619), 3.0-10.0 mm long, off Inlet Point, Port Chester (Metlakatla), Annette Island, SE Alaska (55°09’N, 131°33’W), at 42 m on clean (z.e., free of silt or mud) gravel. Collected by RNC, 25 August and 3 September 1990. Remarks: An examination of the data of all other known specimens of Dendrochiton semilirata indicates that this species seems to prefer the clean gravel habitat. The new record extends the known range 690 km to the north. Juvenichiton albocinnamomeus Sirenko, 1975 Previous known distribution: Kurile Islands (Paramushir Island to Iturup Island) to Commander Islands, USSR (SIRENKO, 1975b), intertidal to 45 m on the alga Thalas- stophyllum clathrum. New records: One hundred and three specimens (five LACM 141150), 1.5-8.0 mm long, Ram’s Head Point, near en- trance to Chernofski Harbor, NW end of Unalaska Island, Aleutian Islands, Alaska (53°24'N, 167°32’W), intertidal on Thalassiophyllum clathrum. Collected by RNC and Da- vid Forrester, 1-2 April 1985. Forty-seven specimens (RNC), 2.0-8.0 mm long, Ko- rovin Bay, Atka Island, Aleutian Islands, Alaska (52°14'N, 174°18'W), intertidal to 6 m on Thalassiophyllum clathrum. Collected by RNC, 21 August 1985. Remarks: KAAS & VAN BELLE (1985) placed this species in the synonymy of Juvenichiton saccharinus (Dall, 1878) on the basis of the examination of a paralectotype of Toni- cella saccharina Dall (USNM 30912) from Kiska Island, Aleutian Islands, in comparison with topotypes of /. al- bocinnamomeus from Onekotan Island, Kurile Islands. However, I believe this synonymy to be an error. Juvenichiton albocinnamomeus is a valid species, and Ju- venichiton kommandorensis Sirenko, 1975 (described as en- demic to the Commander Islands) is a synonym of /. sac- charinus. The original syntype series of Tonicella saccharina was from various localities in the Shumagin and Aleutian Islands, and may have included specimens of both of these similar species. FERREIRA (1982) designated the syntype series as lectotype (USNM 30914, larger specimen) and paralectotypes (USNM 30914, smaller specimen, USNM 30913, USNM 30912, and USNM 30911). Another spec- imen from the original syntype series is in the S. S. Berry collection (SBMNH 34457). The Berry specimen is from the type locality—Yukon Harbor, Big Koniuji Island, Shumagin Islands—and bears the same data as the lec- totype. A comparison of the Berry specimen, along with photographs of the lectotype (through the kindness of the late Dr. Antonio J. Ferreira), five topotypes of J. kom- mandorensis (through the kindness of Dr. B. I. Sirenko, ZIAS) and two specimens from Ram’s Head Point, near the entrance to Chernofski Harbor, Unalaska Island, Aleutian Islands (RNC, 1 April 1985, 12 m on the alga Constantinea subulifera), with three topotypes of J. albocin- namomeus (also from Sirenko) and the more than one Notes, Information & News hundred specimens from the Aleutians revealed the error. I believe that the paralectotype of 7. saccharina designated by Kaas & VAN BELLE (1985) is a specimen of /. albocin- namomeus, but the lectotype and the Berry specimen are identical to the topotypes of /. kommandorensis. Thus I recommend that /. kommandorensis be treated as a synonym of J. saccharinus, and J. albocinnamomeus be reinstated as a valid species. Juvenichiton albocinnamomeus is found exclusively on the alga Thalassiophyllum clathrum, from the intertidal to a depth of about 45 m. At depths of 10-45 m, /. saccharinus lives only on the alga Constantinea subulifera. Juvenichiton albocinnamomeus may be distinguished from J. saccharina by the color of the valves; /. saccharinus has red central areas and white lateral areas whereas /. al- bocinnamomeus is overall cream to tan, usually with red- dish-brown jugal triangles, although some specimens are solid cream colored. The new records extend the known range about 1200 km to the east. Juvenichiton deplanatus Sirenko, 1975 Previous known distribution: Northern Kurile Islands (Pa- ramushir Island and Makanrushi Island) to Commander Islands, USSR (SIRENKO, 1975b), intertidal to 10 m on rocks. New record: Three specimens (one LACM 141158), 1.5- 3.0 mm long, Nazan Bay, Atka Island, Aleutian Islands, Alaska (52°12'N, 174°11’W), 5-6 m on rocks. Collected by RNC, 22 August 1985. Remarks: Juvenichiton deplanatus may be distinguished from Micichiton grandispina and Spongioradsia aleutica by the lack of large, ribbed or striated scales on the girdle and by the shape of the valves. Juvenichiton deplanatus, like M. grandispina has 11 teeth per transverse row of the radula. The new record extends the known range about 1200 km to the east. Micichiton grandispina Sirenko, 1975 Previous known distribution: Kurile Islands (Paramushir Island to Urup Island) to Commander Islands (SIRENKO, 1975b), 0-50 m. New record: Two specimens (one LACM 141151), 2.0 and 4.0 mm long, Korovin Bay, Atka Island, Aleutian Islands, Alaska (52°14'N, 174°18’W), intertidal on rocks. Collected by RNC, 21 August 1985. Remarks: This small species may be distinguished from the very similar appearing Spongioradsia aleutica, with which it shares the same habitat, by the stronger sculpture on the lateral areas, the unislitted intermediate valves, and the radula, which has only 11 teeth per transverse row instead of the normal 17. The new record extends the known range 1200 km to the east. Page 93 ISCHNOCHITONIDAE Lepidozona cooper: (Carpenter MS, Dall, 1879) Previous known distribution: Neah Bay, Clallum County, Washington State (RICE, 1972) to Punta Santo Tomas, Baja California Norte, Mexico (FERREIRA, 1978), inter- tidal to 20 m. New record: Two specimens (one LACM 141161), 33.0 and 34.5 mm long, S side of Quisitus Point, Florencia Bay, SW Vancouver Island, British Columbia, Canada (49°00’N, 125°40'W), intertidal on bottoms of rocks. Collected by Graham and Sue Jeffrey, 2 July 1986. Remarks: The new record extends the known range about 62 km to the north. Lepidozona scabricostata (Carpenter, 1864) Previous known distribution: Cape Flattery, Clallum Coun- ty, Washington (FERREIRA, 1978) to Sebastian Vizcaino Bay, Baja California Norte, Mexico (FERREIRA, 1978), intertidal (extremely rare) and 30-1460 m on rocks and sand. New records: One specimen (RBCM, Cowan Collection No. 6760), 14 mm long, off Biorka Island, Sitka Sound, Baranof Island, Alaska (42°04'N, 124°17'W), 201-208 m. One specimen (RNC) 6.0 mm long, Gulf of Alaska, W of Icy Point, SE Alaska (58°35.03'N, 138°27.25'W), 190 m. Collected by Rae Baxter, 16 August 1987. Three specimens (one LACM 141149), 5.5-6.0 mm long, Gulf of Alaska, SW of Lituya Bay (Glacier Bay National Monument) (57°50.12’N, 136°48.71'W), 119 m. Collected by Rae Baxter, 12 August 1987. Remarks: The new records extend the known range 1175 km to the north. Lepidozona (Tripoplax) ima Sirenko, 1975 Previous known distribution: NW Pacific Ocean, near Com- mander Islands, USSR (SIRENKO, 1975a) and off Baranof Island, SE Alaska (KAAS & VAN BELLE, 1987), 100- 1180 m. New records: One specimen (RNC), 16.0 mm long, Bering Sea, N of Umnak Island, Aleutian Islands, Alaska (52°50.71'N, 168°22.56’W), 228-274 m on small boulder. Collected by RNC, 2 June 1985. Four specimens (one LACM 141154), 18.0-25.0 mm long, S of Rat Island, Aleutian Islands, Alaska (51°53.34'N, 179°45.58’E), 121 m on rocks. Collected by Rae Baxter, 7 September 1986. Remarks: This is the first record of Lepidozona ima in the Aleutians, and bridges the gap in its previous known dis- tribution. Lepidozona (Tripoplax) regularis (Carpenter, 1855) Previous known distribution: Crescent City, Del Norte County, California (CHACE & CHACE, 1933) to San Diego, Page 94 San Diego County, California (KAAS & VAN BELLE, 1987), intertidal to 15 m. New records: Five specimens (one LACM 141153), 19.0- 33.5 mm long, S end of Harris Beach, Brookings, Curry County, Oregon (42°05'N, 124°17'W), 1-1.5 m on bottoms of large rocks. Collected by RNC, 28 July 1982. Seven specimens (RNC), 22.5-37.0 mm long, N of Zwagg Rock, Mill Beach, Brookings, Curry County, Or- egon (42°04'N, 124°17'W), 1-5 m on bottoms of large smooth rocks. Collected by RNC and Dan Kerns, 27 Au- gust 1984. Remarks: The new records extend the known range 37 km to the north. Lepidozona (Tripoplax) trifida (Carpenter, 1864) Previous known distribution: Shumagin Islands, Alaska, to Puget Sound, Washington State (BURGHARDT & BURG- HARDT, 1969), intertidal to 110 m on rocks. New record: One specimen (LACM 141157), 19.0 mm long, Dutch Harbor, Unalaska Island, Aleutian Islands, Alaska (55°54'N, 166°31’W), 7 m on rock. Collected by Rae Baxter, 22 September 1986. Remarks: A wolf-eel (Annarhichthys ocellatus) taken at 82 m, NE of Middleton Island, Gulf of Alaska (leg. Rae Baxter, 16 July 1989) contained the partially digested remains of three adult specimens (two LACM 141169) of Lepidozona trifida in its stomach, indicating that this chiton is actively preyed upon. The new record extends the known range about 385 km to the west. Stenosemus stearnsiu (Dall, 1902) Previous known distribution: Trinidad, Humbolt County, California (TALMADGE, 1973) to Santa Clemente Island, San Diego, California (FERREIRA, 1978), 439-648 m. New record: One specimen (CAS 012626), 14.0 mm long, SW of Seaside, Clatsop County, Oregon (45°50'N, 124°43.03’W), 400 m. Remarks: The new record extends the known range 650 km to the north. MOPALIIDAE Mopalia imporcata (Carpenter, 1864) Previous known distribution: Kachemak Bay, Kenai Pen- insula, Cook Inlet, Alaska (CLARK, 1983, as Mopalia cith- ara Berry, 1951) to La Jolla, San Diego County, California (BURGHARDT & BURGHARDT, 1969), intertidal to 120 m. New record: Four specimens (one LACM 141165), 8.0- 23.5 mm long, Punta Santo Tomas, Baja California Norte, Mexico (31°34'N, 116°40'W), intertidal to 3 m on bottoms of rocks. Collected by RNC and David Forrester, 26 Jan- uary 1982. Remarks: A comparison of the holotype of Mopalia cithara The Veliger, Vol. 34, No. 1 Berry, 1951 (SBMNH 34422) with over 50 specimens of M. imporcata (Carpenter, 1864) from various depths and localities from Alaska to Baja California revealed them to be identical in all respects, except for a slight variation in the sculpture of the ribs of the head valve and lateral areas of intermediate valves. I thus recommend that M. cithara be treated as a synonym of M. imporcata. The new record extends the known range about 140 km to the south. Mopalia lionota Pilsbry, 1918 Previous known distribution: San Pedro, Los Angeles Coun- ty, California, to La Jolla, San Diego County, California (BURGHARDT & BURGHARDT, 1969), intertidal. New records: Two specimens (one LACM 141168), 14.0 and 16.0 mm long, Punta Descanso, Baja California Norte, Mexico (32°14’N, 116°58’W), extreme low intertidal, in algal moss on top of large rocks. Collected by George A. Hanselman, 15 January 1980. Two specimens (RNC), both 13.5 mm long, Govern- ment Point, 1 km S of Point Conception, Santa Barbara County, California (34°26.5'N, 120°27’W), intertidal in moss on tops of rocks. Collected by RNC, 22 November 1988. One specimen (RNC), 24.0 mm long, Shell Beach, San Luis Obispo County, California (35°10'N, 120°40’W), in- tertidal on top of rock. Collected by RNC, 7 January 1986. Three specimens (one LACM 141159), 16.5-20.5 mm long, Lighthouse Beach, Santa Cruz, Santa Cruz County, California (36°58’N, 122°03’W), intertidal on tops of rocks. Collected by RNC, 12 March 1989. Remarks: The new records extend the known range 355 km to the north and about 80 km to the south. Mopalia phorminx Berry, 1919 Previous known distribution: Gulf of Alaska to Santa Mon- ica Bay, Los Angeles County, California (CLARK, 1983), 18-183 m. New record: Two specimens (one LACM 141164), 9.0 and 11.0 mm long, Naked Island, Prince William Sound, Alas- ka (60°37.8'N, 146°23'W), 28-31 m on broken shell and gravel bottom. Collected by RNC, 10 April 1985. Remarks: The new record extends the known range 125 km to the north. Mopalia spectabilis Cowan & Cowan, 1977 Previous known distribution: Kodiak Island and Kenai Pen- insula, Alaska (CLARK, 1983) to San Luis Obispo County, California (CLARK, 1983), intertidal to 10 m on bottoms of rocks. New record: Three specimens (one LACM 141166), 27- 40 mm long, Government Point, 1 km S of Point Concep- tion, Santa Barbara County, California (34°26.5'N, 120°27'W), intertidal under rock ledges. Collected by RNC, 22 November 1988. Notes, Information & News Remarks: Mopalia spectabilis is found on the bottoms of rocks and on rocky outcroppings and under ledges covered with the bright red, social ascidian Metandrocarpa taylori and red and yellow, encrusting, siliceous sponges (Hali- clona spp.), upon which it apparently feeds. The new record extends the known range 80 km to the south. Mopalia sinuata (Carpenter, 1864) Previous known distribution: Kachemak Bay, Kenai Pen- insula, Cook Inlet, Alaska (BAXTER, 1983) to Monterey, Monterey County, California (BURGHARDT & BURG- HARDT, 1969), intertidal to 200 m. New record: One specimen (LACM 141160), 11.0 mm long, off Avila Beach, San Luis Obispo County, California (35°11.50’N, 120°45’W), 25 m on side of boulder covered with pink, encrusting, coralline algae (Lithothamnium sp.) Collected by RNC, 3 January 1986. Remarks: Mopalia sinuata is usually found on the sides of rocks and boulders, in (often silty) crevices, covered with pink, encrusting coralline algae of the genus Lithotham- nium. I have also collected specimens on the shells of living Fusitriton oregonensis, Haliotis rufescens, and H. kamchat- kana. The new record extends the known range 160 km to the south. Mopalia swanu (Carpenter, 1864) Previous known distribution: Shumagin Islands, Aleutian Islands, Alaska, to Malibu, Los Angeles County, Califor- nia (BURGHARDT & BURGHARDT, 1969), intertidal. New record: Five specimens (one LACM 141163), 28.0- 41.0 mm long, Dutch Harbor, Unalaska Island, Aleutian Islands, Alaska (55°54’N, 166°31'W), intertidal on sides and tops of rocks. Collected by RNC, 30 August 1985. Remarks: The new record extends the known range 385 km to the west. Placiphorella borealis Pilsbry, 1892 Previous known distribution: Bering Island, Commander Islands, Bering Sea, USSR (PiLssry, 1892) to Hokkaido Island, Japan (SAITO & OKUTANI, 1989), intertidal and shallow subtidal. New record: Three specimens (one LACM 141155), 20- 41 mm long, Korovin Bay, Atka Island, Aleutian Islands, Alaska (52°14’N, 174°18’W), intertidal and 12-18 m on bottoms of large rocks. Collected by RNC, 21 August 1985. Remarks: SIRENKO (1973) reported that Placiphorella bo- realis broods its young in its pallial grooves; this is the only member of the Mopaliidae known to do this. An exami- nation of the specimens from Atka did not reveal any young. BERRY (1917b) described what he mistook to be this species in material dredged off Cape Rollin, Simushir Is- land, Kurile Islands, USSR, at 228 fathoms (416 m) by Page 95 the Albatross expedition in 1906. An examination of two of these specimens (SBMNH 35135) revealed them to be Placiphorella pacifica Berry, 1919. Thus, P. borealis is chief- ly an intertidal species, but is also found subtidally to at least 18 m on rocks. The new record exends the known range 1200 km to the east. Placiphorella pacifica Berry, 1919 Previous known distribution: Sea of Okhotsk, USSR (Ya- KOVLEVA, 1952, as Placiphorella ushakovi, fide SMITH, 1975) to off Guaymas, Sonora, Mexico (Gulf of California) (SMITH, 1975), 155-2000 m. New records: Two specimens (LACM. uncatalogued), curled, eastern Indian Ocean, South Tasmanian Ridge (42°21'S to 47°18’S, 147°52'E to 147°51'E). Collected by Eltanin, Cruise No. 27, Station No. 1984, 24 February 1967. Trawled, 910-915 m. One specimen, 22 mm long, examined through the kind- ness of the late Dr. Antonio J. Ferreira (on loan to him from R. Pena), from off Errazuia, Antofagasta Province, Chile (latitude and longitude unknown); depth and date not stated. Remarks: In the Aleutian Islands, I have collected adults and juveniles (6.0-36.0 mm long) on large cobbles and boulders, and juveniles (6.0-10.5 mm long) on the giant abyssal barnacle Balanus evermanni at depths of 210- 274 m. TAKI (1954) described Placiphorella albitestae from 200- 550 m off the Pacific coast of Honshu Island, Japan. A comparison of Taki’s description and excellent figures with specimens of P. pacifica (including the lectotype, SBMNH 34394) demonstrated that they are identical in valve mor- phology and color, girdle setae structure, and radular char- acteristics. Thus, I recommend that P. albitestae be treated as a synonym of P. pacifica. The new records indicate that Placiphorella pacifica is distributed throughout the Pacific Ocean, and in the east- ern Indian Ocean. Placiphorella rufa Berry, 1917 Previous known distribution: Kachemak Bay, Kenai Pen- insula, Alaska (BAXTER, 1983) to Forrester Island, Alaska (BERRY, 1917a), intertidal to 45 m on rocks. New records: Six specimens (RBCM 976-1064-5), 25-46 mm long, off Walters Point, Owen Bay, Sonora Island, British Columbia, Canada (50°18’N, 125°09’W), 29 m on rocks. Collected by P. Lambert, 1 August 1976. One specimen (RBCM 976-1046-2), 24 mm long, Ed- ward King Island, Barclay Sound, SW Vancouver Island, British Columbia, Canada (48°49.50’N, 125°12.50’W), 29 m. Collected by P. Lambert, 14 June 1976. Remarks: In southeastern Alaska Placiphorella rufa is found on boulders, cobbles, and rock ledges covered with crustose, pink coralline algae (Lithothamnium spp.). Page 96 The new records extend the known range 680 km to the south. Placiphorella velata Carpenter, in Dall, 1879 Previous known distribution: Forrester Island, Alaska (BERRY, 1917a) to Todos Santos Bay, Baja California Norte, Mexico (PILSBRY, 1892), intertidal to 18 m on bottoms of rocks and in crevices. New records: Four specimens (RNC), 31-40 mm long, Saint Lazaria Island, Kruzof Island (56°55'N, 135°45’W), at the entrance to Sitka Sound, Baranof Island, Alaska, intertidal on bottoms of boulders. Collected by RNC, 2 June 1983. Two specimens (one LACM 141156), 24 and 36 mm long, English Bay, Hichinbrook Island, Prince William Sound, Alaska (60°17.03’N, 146°40.07’W), intertidal in rock crevices. Collected by RNC, 15 April 1986. Remarks: In Oregon this species is often found in sea urchin (Strongylocentratus purpuratus) excavations in bedrock ex- posed to heavy surf. Reports of Placiphorella stimpsoni (Gould, 1859) in Alaskan waters (BURGHARDT & BURGHARDT, 1969; PUTMAN, 1980; BAXTER, 1983, 1987) are misidentifica- tions of P. velata. The new records extend the known range 625 km to the north. Acknowledgments For the use of specimens and data in their private and institutional collections I am grateful to the following peo- ple; Rae Baxter, Red Mountain, Alaska; Dr. Ian Mc- Taggart Cowan, Victoria, British Columbia; Gorden Green, Royal British Columbia Museum; Dr. James H. McLean, Los Angeles County Museum of Natural His- tory, Los Angeles; Michael Kellogg and Elizabeth Kools, California Academy of Sciences, San Francisco; Mr. Paul Scott, Santa Barbara Museum of Natural History, and Dr. B. I. Sirenko, Zoological Institute Academy of Sci- ences, Leningrad (for the gift of many comparative spec- imens). For their helpful suggestions and critical reading of the manuscript, I thank Dr. James T. Carlton (formerly of the Oregon Institute of Marine Biology) and Dr. Ian McTaggart Cowan of Victoria. Literature Cited BAXTER, R. 1983. Mollusks of Alaska. China Poot Bay Society Publ.: Homer, Alaska. 96 pp. BAXTER, R. 1987. Mollusks of Alaska. 2nd ed. Shells and Sea Life Inc.: Bayside, California. 163 pp. Berry, S. S. 1917a. Notes on west American chitons. I. Pro- ceedings of the California Academy of Sciences (4)7(10): 229-248; 4 text figs. BERRY, S.S. 1917b. Chitons taken by the United States Fish- eries steamer “Albatross” in the northwest Pacific in 1906. The Veliger, Vol. 34, No. 1 Proceedings of the U.S. National Museum 54(2223):1-18; pls. 1-10. BURGHARDT, G. E. & L. E. BURGHARDT. 1969. A Collector’s Guide to West Coast Chitons. Special Publication No. 4, San Francisco Aquarium Society. 45 pp., 4 color pls., 7 text figs. CuacgE, E. P. & E. M. H. CHaAce. 1933. Field notes on chitons of Crescent City, California. The Nautilus 46(4):123-124. CiarK, R. N. 1983. Range extensions for some Pacific coast chitons. Of Sea and Shore 13(1):31. EERNISSE, D. J. 1986. The genus Lepidochitona Gray, 1821 (Mollusca: Polyplacophora) in the northeastern Pacific Ocean (Oregonian and Californian Provinces). Zoologische Ver- handelingen (Leiden) 228:3-52. FERREIRA, A. J. 1978. The genus Lepidozona (Mollusca: Poly- placophora) in the temperate eastern Pacific, Baja California to Alaska, with the description of a new species. The Veliger 21(1):19-44, figs. 1-34. FERREIRA, A. J. 1982. The family Lepidochitonidae Iredale, 1914 (Mollusca: Polyplacophora) in the northeastern Pa- cific. The Veliger 25(2):93-138, figs. 1-97. Kaas, P. & R. A. VAN BELLE. 1985. Monograph of Living Chitons. Vol. II. Dr. Backhuys Publisher: Rotterdam. 198 PP- Kaas, P. & R. A. VAN BELLE. 1987. Monograph of Living Chitons. Vol. III. Dr. Backhuys Publisher: Rotterdam. 302 PP- PitsBry, H. A. 1892. Monograph of the Polyplacophora. Jn: G. W. Tryon, Manual of Conchology, 14:1-128, pls. 1-30. PUTMAN, B. F. 1980. Taxonomic identification key to the de- scribed species of polyplacophoran mollusks of the West Coast of North America (north of Mexico). Report, Pacific Gas and Electric Company, Department of Engineering Re- search 4111.79.342:i-v, 1-165, figs. 1-68. RicE, T. C. 1972. Marine Shells of the Pacific Coast. Ellis Robinson Publisher: Everett, Washington. 102 pp., 40 color pls. SaiTo, H. & T. OKUTANI. 1989. Revision on shallow-water species of the genus Placiphorella (Polyplacophora: Mopali- idae) from Japan. The Veliger 32(2):209-227. SIRENKO, B. I. 1973. A new genus of the family Lepidopleu- ridae (Neoloricata). Zoologicheskii Zhurnal 52(10):1569- 1571, figs. 10-16 (in Russian). SIRENKO, B.I. 1975a. On the taxonomy of the genus Lepidozona Pilsbry. Biologya Belogo Morya Moskva 3:13-28, figs. 1-6 (in Russian). SIRENKO, B.I. 1975b. Anew subfamily of mail-shells Juvenich- itoninae (Ischnochitonidae) from the north-west Pacific. Zoologicheskii Zhurnal 54(10):1442-1451, figs. 1-5 (in Russian). SMITH, A. G. 1975. The deep water chiton, Placiphorella pa- cifica. The Veliger 17(2):159-161. Taki, I. 1954. Fauna of chitons around Japanese islands. Bul- letin of the National Science Museum, Tokyo 34:22-28, pls. 11-15. TALMADGE, R. R. 1973. Additional notes on some Pacific coast molluscs—geographical, ecological, and chronological. The Veliger 15(3):232-234. YAKOVLEVA, A. M. 1952. Shell-bearing mollusks (Loricata) of the seas of the U.S.S.R. Fauna USSR 45:1-107, figs. 1-53, pls. 1-11 (Zool. Inst. Acad. Sci. U.S.S.R., Moscow and Len- ingrad). Translated into English by the Israel Program for Scientific Translations, Jerusalem, 1965. Information for Contributors Manuscripts Manuscripts must be typed on white paper, 812” by 11”, and double-spaced throughout (including references, figure legends, footnotes, and tables). If computer generated copy is to be submitted, margins should be ragged right (7.e., not justified). To facilitate the review process, manuscripts, including figures, should be submitted in triplicate. 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Stohler, Founding Editor ISSN 0042-3211 Volume 34 April 1, 1991 Number 2 CONTENTS Review of the Flabellinidae (Nudibranchia: Aeolidacea) from the tropical Indo- Pacific, with the descriptions of five new species. SRERRENCEViniGOSEINER AND) RICHARD @; WILLAN ......:...2...:.:.- OF Nudibranch spermatozoa: comparative ultrastructure and systematic importance. OHNE MeSrinAbY AND RICHARDG) WILLAN 22)... 00 62 be cee cen ee lees 134 Acochlidium fujiensis sp. nov. (Gastropoda: Opisthobranchia: Acochlidiacea) from Fiji. [Nem EEAVINESPAND VWWegINENGHINGTON (0 )o 5 joc ee Se ie we lee wees 166 Taxonomy of Japanese species of the genera Mopalia and Plaxiphora (Polypla- cophora: Mopaliidae). ROSH SATMOFAND MlAKASHT OKUDAND 44.4 neo dee ee. 172 Helicoradomenia juani gen. et sp. nov., a Pacific hydrothermal vent Aplacophora (Mollusca: Neomeniomorpha). AMEDD bes SCHELTEMAVAND ALAN MO IKWZIRIAN {.........-2.22-5:24- 195 Chaetoderma argenteum Heath, a northeastern Pacific aplacophoran mollusk re- described (Chaetodermomorpha: Chaetodermatidae). AMELIE H. SCHELTEMA, JOHN BUCKLAND-NICKS, AND FU-SHIANG CHIA .. 204 Mollusca of Assateague Island, Maryland and Virginia: a reexamination after seventy-five years. CLEMENT LL. Counts, Ill AND TERRY L. BASHORE .................... 214 CONTENTS — Continued The Veliger (ISSN 0042-3211) is published quarterly on the first day of January, April, July, and October. Rates for Volume 34 are $28.00 for affiliate members (including domestic mailing charges) and $58.00 for libraries and nonmembers (in- cluding domestic mailing charges). For subscriptions sent to Canada and Mexico, add US $4.00; for subscriptions sent to addresses outside of North America, add US $8.00, which includes air-expedited delivery. Further membership and subscription infor- mation appears on the inside cover. 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The Veliger 34(2):97-133 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Review of the Flabellinidae (Nudibranchia: Aeolidacea) from the Tropical Indo-Pacific, with the Descriptions of Five New Species by TERRENCE M. GOSLINER Department of Invertebrate Zoology and Geology, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, USA AND RICHARD C. WILLAN Department of Zoology, University of Queensland, Queensland 4072, Australia Abstract. The morphology and systematics of seven members of the Flabellinidae are described and discussed. Coryphella Gray, 1850, and Coryphellina O’ Donoghue, 1929, are maintained as synonyms of Flabellina Voigt, 1834. The morphological variability of F. bicolor (Kelaart, 1858) is fully described and F. annuligera (Bergh, 1900), F. ornata (Risbec, 1928), and F. alisonae Gosliner, 1980, are considered as synonyms. Flabellina rubrolineata (O’ Donoghue, 1929) is recorded from several localities from Aldabra Atoll to Enewetak Atoll. Five new species of Flabellina are described. Flabellina riwo sp. nov., F. bilas sp. nov., and F. rubropurpurata sp. nov. have perfoliate rhinophores and are closely allied to F. bicolor. Two other species, F. delicata sp. nov. and F. exoptata sp. nov., have papillate rhinophores and are most closely allied to F. rubrolineata, F. poenicia, and F. marcusorum. The phylogeny of two clades of flabellinids is further elucidated, based upon the examination of several new taxa. The biogeography of the Flabellinidae is discussed relative to the proposed phylogenetic hypothesis. INTRODUCTION The Flabellinidae have received considerable attention in recent years (MILLER, 1971; KUZIRIAN, 1979; GOSLINER & GRIFFITHS, 1981; GOSLINER & KUZIRIAN, 1990), but the emphasis of most systematic treatments has been upon temperate species, rather than upon tropical members of the family. Recent collections of opisthobranchs from several local- ities within the Indo-Pacific tropics, including Fiji, Aus- tralia, Papua New Guinea, the Seychelles, Madagascar and Aldabra, have brought to light specimens of seven species of Flabellinidae. The members of this family are poorly known in the Indo-Pacific and provide the focus of this systematic and morphological study. SPECIES DESCRIPTIONS Flabellina bicolor (Kelaart, 1858) (Figures 1A, 2-5) Eolis bicolor KELAART, 1858:115; KELAART 1859:490. Aeolis bicolor (Kelaart, 1858): KELAART, 1883:104. Samla annuligera BERGH, 1900:237, pl. 20, figs. 47-55. Samla bicolor (Kelaart, 1858): ELIOT, 1906:685, pl. 45, fig. 4. Coryphella ornata RISBEC, 1928:266, pl. 11, fig. 1, text fig. 89, nos. 1, 2; RIsBEc, 1953:143, fig. 98a; BaBA, 1936: 44, fig. 26, pl. 2, fig. b., syn. nov. Flabellina ornata (Risbec, 1928): BABA, 1955:29, fig. 48, pl. 15, figs. 42, 43; WILLAN & COLEMAN, 1984:42, fig. 134. syn. nov. Page 98 The Veliger, Vol. 34, No. 2 Flabellina alisonae GOSLINER, 1980:40, figs. 1, 2; BERTSCH & JOHNSON, 1981:88; JOHNSON & BOUCHER, 1984:283. syn. nov. Flabellina ornata Angas: ORR, 1981:72. (non Flabellina ornata Angas, 1864). syn nov. Distribution: This species is widespread throughout the Indo-Pacific and is known from the Hawaiian Islands (BERGH, 1900; GOSLINER, 1980; BERTSCH & JOHNSON, 1981; present study), the Marshall Islands (JOHNSON & BOUCHER, 1984); Fiji (present study), New Caledonia (RISBEC, 1928); Guam (present study); Australia (WILLAN & COLEMAN, 1984); Okinawa (BABA, 1936; present study), Japan (BaBA, 1955), Hong Kong (ORR, 1981), Papua New Guinea (present study), Sri Lanka (KELAART, 1858, 1859, 1883; ELIoT, 1906), the Seychelles (present study), Re- union (present study), Madagasar (present study) and South Africa (present study). Material: Twelve specimens, California Academy of Sci- ences, San Francisco, CASIZ 070558, 1 dissected, N end Mahe Island, Republic of Seychelles, 21 April 1984, T. M. Gosliner. One specimen, CASIZ 070563, 1 km N of Mahe Beach Hotel, Mahe Island, Republic of Seychelles, 3 May 1984, T. M. Gosliner. Three specimens, CASIZ 070564, Anse Takamaka, Mahe Island, Republic of Sey- chelles, 2 May 1984, T. M. Gosliner. Ten specimens, CASIZ 070565, N of Beau Vallon, Mahe Island, Republic of Seychelles, 21 April 1984, T. M. Gosliner. One spec- imen, CASIZ 070559, lagoon between Passe Femme and Passe DuBois, Aldabra Atoll, Seychelles, 19 March 1986, T. M. Gosliner. Three specimens, CASIZ 070560, Middle Camp, Aldabra Atoll, Seychelles, 18 March 1986, T. M. Gosliner. Seven specimens, CASIZ 070561, 070562, 070610, Passe Femme, Aldabra Atoll, Seychelles, 19-23 March 1986, T. M. Gosliner. One specimen, CASIZ 070600, reef flat, NE of pass through reef 5 km WSW of Mora Mora Village, Madagascar, 8 April 1988, T. M. Gosliner. Six specimens, CASIZ 070601, near Sea Stack, NW side of Nosy Tanikely, Madagascar, 14 April 1989, T. M. Gosliner. Two specimens, CASIZ 070602, point on N side of Andilana Beach, Nosy Be, Madagascar, 15 April 1989, T. M. Gosliner. Two specimens, CASIZ 070603, point NW of Village Beach, Nosy Komba, Mad- agascar, 16 April 1989, T. M. Gosliner. One specimen, CASIZ 070566, Barracuda Point, Pig Island, Madang, Papua New Guinea, 13.7 m depth, 29 January 1988, T. M. Gosliner. Two specimens, CASIZ 070568, dissected, N side of patch reefs, N side of Kranket Island, Madang, Papua New Guinea, 22.7 m depth, 24 January 1988, T. M. Gosliner. One specimen, CASIZ 070569, dissected, Rempi Lagoon, N of Madang, Papua New Guinea, 13.7 m depth, 3 February 1988, T. M. Gosliner. One specimen, CASIZ 070604, Cement Mixer Reef, Madang, Papua New Guinea, 17 October 1986, T. Frohm. One specimen, CASIZ 070605, Cement Mixer Reef, Madang, Papua New Guinea, 6.1-7.6 m depth, 20 October 1986, M. Ghi- selin. Three specimens, CASIZ 070606, Cement Mixer Reef, Madang, Papua New Guinea, 6 m depth, 19 October 1986, T. M. Gosliner. One specimen, CASIZ 070607, patch reef, N end Kranket Island, Madang, Papua New Guinea, 10.7 m depth, 1 October 1986, T. M. Gosliner. One specimen, CASIZ 070608, opposite lab, between Pig Island and Massis Island, Madang, Papua New Guinea, 15.2 m depth, 30 September 1986, T. M. Gosliner. One specimen, CASIZ 070609, near lighthouse, Madang, Pa- pua New Guinea, 33.5 m depth, 15 January 1988, T. M. Gosliner. Nine specimens, CASIZ 070567, intertidal, Ke- walo Basin, Mamala Bay, Honolulu, Oahu, Hawaii, 7 February 1986, T. M. Gosliner. One specimen, South African Museum, NB 63, Natal, South Africa, 29 Decem- ber, 1958. One specimen, Kings Headland, Caloudra, Sun- shine Coast, N of Brisbane, Queensland, 6 m depth, 31 May 1981, P. Gofton. One specimen, channel between main islets, Shag Rock, NW of Point Lookout, North Stradbroke Island, Queensland, 10 m depth, 17 June 1981, R. C. Willan. One specimen, under coral slab, outer reef flat, W end of Heron Island, Capricornia Section, Great Barrier Reef, Queensland, low intertidal, 16 July 1981, R. C. Willan. One specimen, “The Nursery,” NW side of Julian Rocks, off Cape Byron, New South Wales, 5 September 1987, C. Buchanan. External morphology: The living animals (Figure 1A) reach a maximum length of 22 mm. The general body color is translucent white or bluish white. Opaque white pigment may be present sparsely or densely on the oral tentacles, head, notum, and cerata. This pigment may en- tirely overlie the translucent white notum or may be pres- ent as discrete patches, separated by areas of translucence, usually at the bases of the ceratal peduncles. Generally, the bases of the oral tentacles, rhinophoral stalks, and cerata are devoid of opaque white, even in the most heavily pigmented individuals. The rhinophoral stalks may be ei- ther opaque or translucent white. More distally, a brown- ish band is present in some individuals and the apical portion is cream or orange. A vivid orange spot or incom- plete or complete ring is present subapically on each ceras. The upper and lower boundaries of the orange pigment are sharply demarcated. The body is narrow and elongate. The notum is high and rounded in profile, continuing as a ridge to the tip of the tail. The tail is elongate and pointed. The oral tentacles are elongate, approximately three times the length of the rhinophores. The tentacles are usually laterally com- a) Figure 1 Living animals. A. Flabellina bicolor (Kelaart, 1858). B. F. riwo sp. nov. C. F. bilas sp. nov. D. F. rubropurpurata sp. nov. E. F. rubrolineata (O’Donoghue, 1929). F. F. exoptata sp. nov. G. F. delicata sp. nov. a 2 E & = O pe 3 g & g oe) 2 - Page 100 The Veliger, Vol. 34, No. 2 Figure 2 Flabellina bicolor (Kelaart, 1858). A. Dorsal view of 13 mm living animal. B. Jaw, scale = 0.1 mm. C. Reproductive system: al, albumen gland; am, ampulla; bc, bursa copulatrix; mu, mucous gland; p, penis; rs, receptaculum seminis; vd, vas deferens; scale = 0.3 mm. pressed, but may become shorter and more cylindrical in animals held in aquaria for more than 24 hr. The rhino- phores are perfoliate with 11-19 lamellae. The anterior foot corners are short, recurved and tentacular, but not acutely pointed. The cerata are generally held erectly in life. They are arranged in 4-8 discrete clusters per side of the body, each elevated on a short but distinct peduncle (Figure 2A). The precardiac and first 1-3 postcardiac rows each contain 3 or 4 cerata. The succeeding 2-4 posterior rows each contain 1 or 2 cerata. The gonopore is situated on the right side of the body, ventral to the anteriormost ceratal cluster. The pleuroproctic anus is located imme- diately below the notal brim, between the precardiac and first postcardiac ceratal rows, nearer the postcardiac cluster (Figure 2A). The nephroproct is immediately dorsal to the anus. Buccal mass: The buccal mass is short and muscular. From the anterior portion of the buccal mass, a pair of highly ramified oral glands extends posteriorly, and fills much of the first ceratal peduncle. The jaws (Figure 2B) are thin and ovoid, with a well- developed masticatory border. The border (Figure 3A) bears approximately 3 rows of denticles. The outer row contains approximately 20 denticles, which are stronger and more prominent than the inner ones. The radula (Figure 3B-D) has a formula of 14-20 x 1-1-1- in the 10 specimens examined. The rachidian teeth (Figure 4) are evenly curved with a pair of elongate pos- terior limbs. There are 7-12 elongate denticles on either side of the longer, wider central cusp. When the rachidian tooth is viewed laterally (Figure 4D), the central cusp is higher than the adjacent denticles. The lateral teeth (Fig- T. M. Gosliner & R. C. Willan, 1991 Page 101 Figure 3 Flabellina bicolor (Kelaart, 1858), scanning electron micrographs. A. Masticatory border of jaw, scale = 40 um. B. Entire radular width, Oahu, Hawaii, scale = 20 wm. C. Entire radular width, Madang, Papua New Guinea, scale = 30 um. D. Entire radular width, Mahe, Seychelles, scale = 40 um. ure 5) are broadly triangular with a basal portion of vari- able length. The primary cusp is triangular and acutely pointed. There are 4-10 denticles along the masticatory margin of the laterals. The size and number of denticles may vary considerably between specimens from a single locality. Reproductive system (Figure 2C): The preampullary duct is elongate and narrow. It widens into a saccate am- pulla. The ampulla divides into a short oviduct and a more elongate vas deferens. The oviduct widens into the serial receptaculum seminis (sensu EDMUNDS, 1970) and nar- rows again as it enters the albumen gland of the female gland mass. A small membrane gland is also present. The bulk of the female gland mass is composed of the mucous gland. Near the exit of the mucous gland into the genital aperture is a thick, recurved bursa copulatrix. The vas deferens widens into a curved prostatic portion. The pro- Page 102 The Veliger, Vol. 34, No. 2 Figure 4 Flabellina bicolor (Kelaart, 1858), scanning electron micrographs of rachidian teeth, scales = 10 um. A. Dorsal view, Oahu, Hawaii. B. Dorsal view, Madang, Papua New Guinea. C. Dorsal view, Mahe, Seychelles. D. Lateral view, Madang, Papua New Guinea. static portion exits directly into the short, indistinct penial papilla adjacent to the female gonopore. Discussion: The systematic status of this widespread spe- cies has been poorly understood. Much of this confusion stems from the incomplete and often inaccurate original descriptions of Eolis bicolor Kelaart, 1858, Samla annuligera Bergh, 1900, and Coryphella ornata Risbec, 1928. BABA (1936, 1955) provided an accurate depiction of the mor- phology of specimens from Okinawa and Japan. GOSLINER (1980) considered specimens from Hawaii as conspecific with Baba’s animals, but distinct from both Bergh’s and Risbec’s species. On this basis Flabellina alisonae was de- scribed. The examination of specimens from much of the Indo-Pacific tropics provides an estimate of the range of variability of this species within and between populations. The color and ceratal arrangement of E. bicolor, S. annu- ligera, and F. alisonae are virtually identical. The only T. M. Gosliner & R. C. Willan, 1991 Page 103 Figure 5 Flabellina bicolor (Kelaart, 1858), scanning electron micrographs of lateral teeth, scales = 10 um. A. Oahu, Hawaii. B, C. Madang, Papua New Guinea. D. Mahe, Seychelles. significant differences between the three species are in the anterior end of the foot (stated to be rounded in E. bicolor and S. annuligera and tentacular in F. alisonae) and the number of rows of denticles on the masticatory border of the jaw (one in F. annuligera and two or three in F. ali- sonae). The corners of the foot may be difficult to differ- entiate when the animal has contracted during preserva- tion. The difference in masticatory border of the jaw may be a result of a poorly prepared specimen where the sec- ondary denticles were not visible. When separating the jaws, part of the masticatory border often pulls away from the rest of the jaw. It may be that only the primary denticles of the border were present on the portion that Bergh il- lustrated. More importantly, no other member of the Fla- bellinidae has only a single row of denticles on the mas- ticatory margin. There are several apparent differences between EFolis bicolor and Coryphella ornata on one hand and Flabellina alisonae on the other. It is not apparent from either Ke- laart’s or Risbec’s figure, or from the descriptions, that the Page 104 The Veliger, Vol. 34, No. 2 Table 1 Morphology of Flabellina species with perfoliate rhinophores. Anterior Denti- right cles on __ Denti- digestive Radular inner _ cles on Central Receptaculum Bursa Species Color branch rows laterals rachidian cusp seminis copulatrix bicolor white to blue with orange 1 row 14-20 4-10 7-12 elevated serial recurved rings on cerata baba blue white with orange 2 rows 18-24 5-8 5-10 depressed serial absent rings on cerata bilas white with opaque white 1 row 21 2-4 9-10 depressed serial short stalk diamonds, red rings on cerata engeli orange with blue tinge 2 rows 19-20 5-10 7-11 depressed semiserial absent and cream markings, cerata with orange bands macassarana pink-yellow 2 rows 17 4-5 — — _ rtwo translucent white with 1 row 15-23 4-7 7-11 elevated absent reduced opaque white network, blue rings on cerata rubropurpurata body purple with red on 3 23-30 3-6 7-9 depressed semiserial stalked cerata, rhinophores red telja reddish with white spots 3-4 rows 14-28 6-9 6-11 depressed semiserial stalked cerata are elevated from the notum on distinct peduncles. Also, the shapes of the jaws and radular teeth depicted by Risbec differ from those described by BABA (1936, 1955) and GOSLINER (1980). It should be noted, however, that Risbec’s drawings are not known for their accuracy. The primary distinction between the two species cited by Gos- liner, was the difference in ceratal arrangement. Gosliner interpreted the formula provided by Risbec as indicating that two precardiac rows of cerata are present on either side of the body. An alternative interpretation is possible. It appears that there may be two rows per side, with each row containing 3 cerata. The first of these rows could be precardiac, the second postcardiac. This would be consis- tent with the distribution of cerata observed in the present material. Since the description of Flabellina alisonae from Hawaii (GOSLINER, 1980), several additional Indo-Pacific records of Flabellina specimens with orange ceratal rings have been published (BERTSCH & JOHNSON, 1981; JOHNSON & BOUCHER, 1984; ORR, 1981; WILLAN & COLEMAN, 1984). The only external differences in these specimens are the amount of opaque white pigment covering the surface of the animal and the completeness of the orange ceratal rings. The range of pigment variability of specimens may vary as much within a locality as between disparate localities. Generally, Hawaiian specimens lack any trace of opaque white pigment, while specimens from Australia and Papua New Guinea may be densely covered with this opaque pigment. Specimens collected from Nosy Be, Madagascar, varied from no opaque white pigment to being densely covered. The amount of orange pigment on the cerata varies considerably within populations of specimens from Australia, Papua New Guinea, and Madagascar. The remainder of the external and internal anatomy of specimens examined in this study varied only slightly and was not correlated to the coloration differences noted above. The radular and reproductive morphology are highly con- sistent within and between populations. It would appear that the described differences between Flabellina bicolor, F. annuligera, F. ornata, and F. alisonae can be attributed to errors in the original descriptions of the former three species. It is more parsimonious to con- sider that a single species of Flabellina, which bears orange pigment on its cerata, is widespread in the Indo-Pacific tropics, in light of the widespread distribution and vari- ability of the species described here. Therefore, F. annu- ligera (Bergh, 1900), F. ornata (Risbec, 1928), and F. al- isonae Gosliner, 1980, are considered to be junior subjective synonyms of F. bicolor (Kelaart, 1858). Two other species of Flabellina have orange ceratal rings, F. engeli Ev. Marcus & Er. Marcus, 1968, and F. baba: Schmekel, 1970. Contrary to F. bicolor, both of these species have two precardiac rows of cerata per side (SCHMEKEL, 1970; EDMUNDs & JusT, 1983) and a depressed central cusp of the rachidian radular teeth. One of us (R.C.W.) has examined live specimens of F. baba: from European waters. Jeff Hamann (personal communication) has pro- vided us with photos of F. engeli from the Caribbean. The coloration of living specimens of these two species is strik- ingly different from that of F. bicolor. The species of Flabellina with perfoliate rhinophores are compared in Table 1. T. M. Gosliner & R. C. Willan, 1991 Page 105 Figure 6 Flabellina riwo Gosliner & Willan, sp. nov. A. Dorsal view of 14 mm living animal. B. Rhinophore, scale = 1.0 mm. C. Jaw, scale = 0.2 mm. D. Reproductive system: al, albumen gland; am, ampulla; bc, bursa copulatrix; me, membrane gland; mu, mucous gland; p, penis; vd, vas deferens; scale = 0.5 mm. Flabellina riwo Gosliner & Willan, sp. nov. (Figures 1B, 6-8) Distribution: This species is known from the northern coast of Papua New Guinea (present study), Manado, Sulawesi, Indonesia (Paulene Fiene-Severns, personal communication), Okinawa (Robert Bolland, personal com- munication), and the northeastern coast of Madagascar (present study). Etymology: The epithet 77wo refers to Riwo Village, ap- proximately 15 km north of Madang, Papua New Guinea, where this species was first found. Type material: Holotype, CASIZ 070952, Cement Mixer Reef, Madang, Papua New Guinea, 3 m depth, 18 October 1986, T. M. Gosliner. One paratype, CASIZ 070953, between Pig Island and Massis Island, near Madang, Papua New Guinea, 15.2 m depth, 30 September 1986, T. Frohm. One paratype, CASIZ 070954, patch reef, Kranket Island, Madang, Pa- pua New Guinea, 10.7 m depth, 1 October 1986, T. M. Gosliner. Three paratypes, CASIZ 070955, patch reef, Kranket Island, Madang, Papua New Guinea, 10.4 m depth, 4 October 1986, T. M. Gosliner. One paratype, CASIZ 070956, Rasch Pass, Madang, Papua New Guin- Page 106 The Veliger, Vol. 34, No. 2 Figure 7 Flabellina riwo Gosliner & Willan, sp. nov., scanning electron micrographs. A. Masticatory border of jaw, Nosy Be, Madagascar, scale = 20 um. B. Entire width of radula, Madang, Papua New Guinea, scale = 30 um. C. Entire width of radula, Nosy Be, Madagascar, scale = 40 um. D. Lateral view of rachidian teeth, Madang, Papua New Guinea, scale = 10 um. ea, 12.2 m depth, 5 October 1986, T. M. Gosliner. One paratype, CASIZ 070957, Barracuda Point, Pig Island, near Madang, Papua New Guinea, 6 October 1986, T. M. Gosliner. One paratype, CASIZ 070958, dissected, Barracuda Point, Pig Island, near Madang, Papua New Guinea, 12.2 m depth, 8 October 1986, T. M. Gosliner. Two paratypes, CASIZ 070959, lighthouse, Madang, Papua New Guinea, 12.2 m depth, 17 October 1986, T. M. Gosliner. Two paratypes, CASIZ 070960, Cement Mixer Reef, Madang, Papua New Guinea, 3 m depth, 18 October 1986, T. M. Gosliner. Two paratypes, CASIZ 070961, Cement Mixer Reef, Madang, Papua New Guin- ea, 6.1 m depth, 19 October 1986, T. M. Gosliner. Three paratypes, CASIZ 070962, Cement Mixer Reef, Madang, Papua New Guinea, 21 October 1986, T. M. Gosliner. One paratype, CASIZ 070968, Barracuda Point, Pig Is- land, near Madang, Papua New Guinea, 15.2 m depth, 13 January 1988, T. M. Gosliner. Four paratypes, USNM T. M. Gosliner & R. C. Willan, 1991 Page 107 Figure 8 Flabellina riwo Gosliner & Willan, sp. nov., scanning electron micrographs, scales = 10 um. A. Dorsal view of rachidian teeth, Madang, Papua New Guinea. B. Dorsal view of rachidian teeth, Nosy Be, Madagascar. C. Lateral teeth, Madang, Papua New Guinea. D. Lateral tooth, Nosy Be, Madagascar. 859085, LACM 2465, ANSP A 13614, Australian Mu- seum, AMS C164081, from same lot as previous specimen. Three paratypes, CASIZ 070969, lighthouse, Madang, Papua New Guinea, 33.5 m depth, 15 January 1988, T. M. Gosliner. One paratype, CASIZ 070970, harbor wharf, Madang, Papua New Guinea, 10.4 m depth, 15 January 1988, T. M. Gosliner. Four paratypes, AMS C164082, coral rubble, the Quarry, near Bunu Village, 30 km N of Madang, Papua New Guinea, 3-5 m depth, 21 January 1988, R. C. Willan. Two paratypes, CASIZ 070971, dis- sected, Barracuda Point, Pig Island, near Madang, Papua New Guinea, 24.4 m depth, 23 January 1988, T. M. Gosliner. Two paratypes, CASIZ 070972, patch reef off Kranket Island, near Madang, Papua New Guinea, 22.7 m depth, 24 January 1988, T. M. Gosliner. One paratype, CASIZ 070973, near the Pinnacle, between Pig Island and Rasch Pass, near Madang, Papua New Guinea, 30.5 m depth, 25 January 1988, T. M. Gosliner. One para- Page 108 type, CASIZ 070974, Hole in the Wall, near Hussein Village, N of Madang, Papua New Guinea, 15.2 m depth, 27 January 1988, R. C. Willan. One paratype, CASIZ 070975, Hole in the Wall, near Hussein Village, N of Madang, Papua New Guinea, 18.3 m depth, 3 February 1988, R. C. Willan. Two paratypes, CASIZ 070976, N point Christmas Bay, Bagabag Island, Papua New Guin- ea, 21.3 m depth, 5 February 1988, T. M. Gosliner and R. C. Willan. One paratype, CASIZ 070977, Barracuda Point, Pig Island, near Madang, Papua New Guina, 10.4 m depth, 8 February 1988, R. C. Willan. One paratype, CASIZ 070963, Barracuda Point, Pig Island, near Ma- dang, Papua New Guinea, 25 m depth, 16 July 1989, T. M. Gosliner. Two paratypes, CASIZ 070965, Barracuda Point, Pig Island, near Madang, Papua New Guinea, 6.1 m depth, 31 August 1989, T. M. Gosliner. Three para- types, CASIZ 070966, one dissected, Sea Stack, NW side Nosy Tanikely, Madagasar, 14 April 1989, T. M. Gos- liner. Two paratypes, CASIZ 070967, one dissected, Ce- ment Mixer Reef, Madang, Papua New Guinea, 3-7.6 m depth, 11 February 1989, T. M. Gosliner. External morphology: The living animals (Figure 1B) reach a maximum of 20 mm in length. Most of the body is translucent white, adorned with a dense, lacy reticulum of opaque white lines. The oral tentacles are opaque white for most of their length, but possess a translucent basal portion near their junction with the head. The basal por- tion of the rhinophores is translucent white; the bulbous, lamellate portion is dull peach to light orange and the apex is translucent white. The base of the cerata may be either translucent white or obscured by opaque white pigment. When translucent, the cream, lobate digestive gland is visible. The apical portions of the cerata are covered with opaque white. Near the middle or in the distal third of each ceras is a broad purple ring. The body is narrow and elongate (Figure 6A). The oral tentacles are three to four times the length of the rhino- phores. The bases of the tentacles are terete whereas the distal third is markedly laterally compressed and paddle- shaped. The rhinophores (Figure 6B) are cylindrical ba- sally and expand into a perfoliate club containing 16-22 densely crowded lamellae. The anterior foot corners are short, tentacular, and recurved. The cerata are arranged in 3-6 pedunculate clusters per side of the body. Each peduncle contains a single row of cerata inserted into an expanded portion of the notal brim. The notal brim is only evident in areas where the cerata are inserted. The pe- duncles contain 1-4 cerata. The ceratal formula varies considerably from small to large individuals. The first postcardiac row generally contains the largest number of cerata. The gonopore is located ventrally to the precardiac ceratal peduncle, on the right side of the body. The anus is situated between the precardiac and first postcardiac rows, generally closer to the more posterior peduncle. The The Veliger, Vol. 34, No. 2 nephroproct is immediately dorsal or slightly anterior to the anal papilla. Buccal mass: The anterior portion of the buccal mass forms a ring immediately inside the mouth. The paired ducts of the highly ramified oral glands originate from this area of the mass. These glands extend into the precardiac ceratal peduncle. The remainder of the buccal mass is highly muscular and contains the ovoid, chitinous jaws (Figure 6C). The masticatory border (Figure 7A) bears 3 or 4 distinct rows of denticles. The outermost row contains 18 elongate denticles with irregular papillae along their surface. The inner denticles decrease in size and papilla- tion. The radula (Figure 7B, C) has a formula of 15-23 x 1-1-1- in three specimens examined. The rachidian teeth (Figures 7D, 8A, B) are broad with an evenly curved posterior end. A deep cleft is present from the postero- medial end of the tooth to the base of the central denticle. The rachidian teeth bear 7-11 narrow denticles on either side of the more elongate central cusp. In lateral view, the central cusp of the rachidian is higher than the adjacent denticles (Figure 7D). The lateral teeth are roughly tri- angular with an elongate base. The primary denticle is elongate and acutely pointed. The masticatory border of the laterals bears 4-7 acutely pointed denticles. Reproductive system (Figure 6D): The preampullary duct is narrow and expands into the saccate ampulla. The ampulla again narrows and divides into the short oviduct and the vas deferens. The oviduct does not expand into a discernible receptaculum seminis. It enters directly into the small albumen gland. The membrane gland is about the same size as the albumen gland and is situated im- mediately ventral to it. The mucous gland comprises the bulk of the female gland and forms the largest portion of the reproductive system. The mucous gland empties into the female gonopore adjacent to the small, thin-walled bursa copulatrix. The vas deferens expands abruptly into a short, thick prostatic portion that is contiguous with the penis. The penial papilla is simple and unarmed. Discussion: Flabellina riwo differs markedly from F. bi- color. It is characterized by an opaque white network of pigment on the body as compared to a powdering of pig- ment in F. bicolor. The cerata bear a bluish purple ring rather than an orange one. Specimens of F. riwo generally have fewer cerata per cluster than does F. bicolor. Inter- nally, F. riwo has broader rachidian teeth, with a distinct medial cleft, which is absent in F. bicolor. The reproductive system differs markedly between the two species; in F. riwo, there is no distinct receptaculum seminis and the bursa copulatrix is reduced, whereas in F. bicolor, both of these receptacles are well developed. The vas deferens is shorter in F. riwo than in F. bicolor. These differences are consistent throughout the extensive geographical ranges of the two species. T. M. Gosliner & R. C. Willan, 1991 Page 109 Figure 9 Flabellina bilas Gosliner & Willan, sp. nov. A. Dorsal view of 18 mm living animal. B. Ventral view of head and foot, scale = 1.0 mm. C. Rhinophore, scale = 0.5 mm. D. Jaw, scale = 0.2 mm. E. Reproductive system: al, albumen gland; am, ampulla; bc, bursa copulatrix; me, membrane gland; mu, mucous gland; p, penis; pr, prostate; rs, receptaculum seminis; vd, vas deferens; scale = 0.5 mm. Flabellina bilas Gosliner & Willan, communication) and from Madang, Papua New Guinea sp. Nov. (present study). (Exgures 1,51!) Material: Holotype, California Academy of Sciences, San Distribution: Flabellina bilas has been found from Kwa- Francisco, CASIZ 070993, living animal 17 mm in length, jalein Island, Marshall Islands (Scott Johnson, personal 20 m depth, Barracuda Point, Pig Island, near Madang, Page 110 The Veliger, Vol. 34, No. 2 ee : \ N yt t } / / ; , Fil i ae SE f : *\ Figure 10 Flabellina bilas Gosliner & Willan, sp. nov., scanning electron micrographs. A. Masticatory border, scale = 30 um. B. Entire width of radula, scale = 50 um. Papua New Guinea, 8 February 1988, G. Williamson. Paratype, CASIZ 070994, living animal 23 mm in length, dissected, collected with the holotype. Etymology: The specific epithet bilas is a New Guinea Pidgin word meaning “decoration,” referring to the bril- liant crimson and blue markings of this species. External morphology: The living animals were 17 and 23 mm in length. The larger individual (the paratype) had lost the posterior portion of its body, perhaps as much as 3-4 mm. The living animals (Figure 1C) are vividly col- ored in a distinctive manner. The general body color is translucent white. There is an orange tinge on either lateral side of the head. The oral tentacles bear two opaque white areas, separating the translucent base, medial region, and apex. Opaque white pigment is also present on the foot corners and as a series of ovoid patches along either side of the body extending from the head to the tail. A series of sky-blue diamond or lozenge-shaped patches is present medially on the notum. These patches may be continuous or well separated. The rhinophores are translucent basally, medially, and apically. They possess two bands of opaque cream pigment and a sharply defined subapical blood-red ring. At the translucent base of some cerata a thin, blood- red digestive diverticulum is visible. More distally, are two broad areas of opaque cream separated by a small area of translucence. Subapically, a broad crimson ring is bordered on either side by a thinner irregular band of opaque white. The animals are elongated and slender (Figure 9A). The oral tentacles are thin and elongate, approximately three times the length of the rhinophores. The distal third of these tentacles is broadly expanded and paddlelike. The foot corners are short and tentacular, and are held nearly perpendicularly to the longitudinal axis of the body, or they may be recurved posteriorly. The anterior margin of the foot is bilabiate (Figure 9B). The perfoliate rhino- phores (Figure 9C) bear 25-28 densely packed lamellae. The notal brim gives rise to a series of pedunculate cerata. There are 7 pairs of ceratal rows in the smaller, intact specimen. The larger one has 6 pairs of ceratal rows, but is missing the posterior portion of its body and tail. The ceratal formulae are: R 4,P,4,3,3,2,1, L 4,P,4,4,2,2,2 in the larger specimen and R & L 4,P,4,3,2,2,1,1 in the smaller individual. The gonopore is located immediately ventral to the preanal ceratal arch while the anus is situated slightly anterior to the median of the interhepatic space, below the notal brim. The nephroproct is immediately dorsal to the anus, but still below the notal brim. Buccal mass: The buccal mass is highly muscular. From its anterior end emanates a pair of oral glands. These begin as simple ducts and branch many times into highly ramified glands, which are present in the precardiac ceratal pe- duncles. The jaws (Figure 9D) are thin and ovoid. Their masticatory border (Figure 10A) contains 4 or 5 rows of denticles. The outermost row bears approximately 20 elon- gate denticles. The denticles of the inner rows are increas- ingly short. The radula (Figure 10B) has a formula of 21 x 1-1- 1- in the paratype. The rachidian teeth (Figure 11A, B) are broad with 9 or 10 elongate denticles on either side of T. M. Gosliner & R. C. Willan, 1991 A Page 111 Figure 11 Flabellina bilas Gosliner & Willan, sp. nov., scanning electron micrographs. A. Dorsal view of rachidian teeth, scale = 20 um. B. Lateral view of rachidian teeth, scale = 30 wm. C. Lateral teeth, scale = 20 um. the equally narrow central cusp. They are deeply indented posteriorly without a distinct medial cleft. When viewed laterally, the central cusp (Figure 11B) is depressed below the level of the adjacent laterals. The lateral teeth are triangular with an elongate base. The primary cusp is irregularly triangular and acutely pointed. The inner cut- ting edge bears 2-4 curved denticles. Reproductive system (Figure 9E): The preampullary duct expands into the saccate ampulla. The ampulla nar- rows and divides into the oviduct and vas deferens. The oviduct expands into a lobate serial receptaculum seminis and again narrows immediately prior to its entrance into the albumen gland. The albumen and membrane glands are small and are adjacent to each other. The mucous gland forms the bulk of the reproductive system and has a large lateral lobe. The mucous gland exits at the female gono- pore. Adjacent to the gonopore is a large, bulbous bursa copulatrix with a short, thick stalk. The vas deferens is narrow for approximately half of its length and expands Page 112 into a coiled prostatic portion. The prostatic section is contiguous with the simple unarmed penis. Discussion: Flabellina bilas can be readily distinguished from the other species with perfoliate rhinophores by its unique pattern of coloration. It is the only species with red bands on the cerata and rhinophores. Together with F. engeli Ev. Marcus & Er. Marcus, 1968, F. bilas has whitish or bluish markings on the notum, between the cerata. However, F. engeli has two precardiac ceratal rows (EDMUNDs & JUST, 1983) rather than one. The repro- ductive morphology also differs considerably. In F. bilas the receptaculum seminis is serial and the bursa copulatrix is present on a short stalk, whereas in F. engeli the recep- taculum seminis is semiserial and the bursa copulatrix is apparently absent (Ev. Marcus & ER. Marcus, 1968). Flabellina bilas is unique among described species of Indo-Pacific flabellinids with perfoliate rhinophores and a single precardiac ceratal row, in having a depressed cusp on the rachidian teeth. Flabellina rubropurpurata Gosliner & Willan, sp. nov. (Figures 1D, 12-14) Flabellina sp. 3: GOSLINER, 1987:114, fig. 223. Distribution: This species is known from Natal, South Africa, Enewetak, Marshall Islands (GOSLINER, 1987), and from Papua New Guinea (present study). Etymology: The epithet rubropurpurata refers to the red cerata and purple body of this species. Type material: Holotype, California Academy of Sci- ences, CASIZ 070995, the Quarry, approximately 1 km S of Cape Croiselles, Madang, Papua New Guinea, 30.5 m (maximum) depth, 11 February 1988, T. M. Gosliner. Two paratpes, CASIZ 070996, Barracuda Point, Pig Island, near Madang, Papua New Guinea, 12.2 m depth, 8 October 1986, T. M. Gosliner. One paratype, CASIZ 070997, the Quarry, approximately 1 km S of Cape Croi- selles, Madang, Papua New Guinea, 10.4 m (maximum) depth, 12 February 1988, T. M. Gosliner. One paratype, CASIZ 070998, Barracuda Point, Pig Island, near Ma- dang, Papua New Guinea, 24.4 m depth, 20 February 1988, T. M. Gosliner. One paratype, South African Mu- seum, Cape Town, SAM A35718, radula only, 9 mile Reef, Sodwana Bay National Park, Natal, South Africa, 10 May 1981, T. M. Gosliner. External morphology: The living animals (Figure 1D) are 4-9 mm in length. The general body color is a deep purple. The distal one-third to one-half of the oral tentacles is opaque white, while the basal portion is purple. The base of each rhinophore is purple; the central portion is opaque white and the distal third is red orange. Opaque white pigment is present along either edge of the notum from the level of the precardiac ceratal cluster to the pos- The Veliger, Vol. 34, No. 2 terior end of the animal. The opaque white pigment may extend onto the lateral and dorsal surfaces of the animal. The cerata are purple basally and orange-red in the middle third; the apical cnidosac is orange. The body (Figure 12A) is elongate and narrow. The notum is high and rounded in profile. The tail is elongate and pointed posteriorly. The oral tentacles are elongate, approximately twice the length of the rhinophores. They are rounded in cross section throughout their length, ex- hibiting no obvious lateral compression. The rhinophores (Figure 12B) are perfoliate with 12 or 13 densely packed lamellae. The anterior foot corners are short, tentacular, and may be extended perpendicularly to the body axis or may be curved. The cerata are short, fusiform, and thickest near the middle of their length. The cerata are arranged on distinct peduncles. The precardiac peduncle contains 3 distinct rows, with 2 or 3 cerata per row. The precardiac ceratal rows are crowded and difficult to differentiate in living specimens. There are 5-7 postcardiac ceratal pe- duncles per side, each consisting of a single row of 1-4 cerata. A distinct notal brim is absent between the pedun- cles. The gonopore is situated on the right side of the body, ventral to the third ceratal row of the precardiac peduncle. The pleuroproctic anus is located immediately below the notum, between the precardiac and postcardiac ceratal pe- duncles. The nephroproct is immediately anterodorsal to the anus. Buccal mass: The muscular buccal mass is small and occupies the anteriormost portion of the body cavity. Ex- tending from the anterior end of the buccal mass are the paired ducts of the oral glands. The glands are highly ramified and occupy much of the precardiac ceratal pe- duncles. The jaws (Figure 12C) are thin and ovoid. They bear 2 or 3 rows of denticles on the surface of the masti- catory border. The radula (Figure 13) has a formula of 23-30 x 1- 1-1: in the two specimens examined. The rachidian teeth (Figure 14A, B) are broadest posteriorly. The posterior limbs are elongate appendages used in articulation of the teeth with each other. The cutting edge of each tooth bears 7-9 elongate denticles on either side of the longer central cusp. In lateral view (Figure 13C) the central cusp of each rachidian tooth is depressed below the level of the adjacent denticles. The lateral teeth (Figure 14C, D) are elongate and triangular with a narrow base and extended primary cusp. There are 3-6 acutely pointed denticles on the mas- ticatory border of the teeth. Reproductive system (Figure 12E): The preampullary duct is short and narrow. It widens into the saccate am- pulla, narrows again, and divides into the oviduct and vas deferens. After a short distance, the narrow oviduct gives rise to the pyriform, semiserial receptaculum seminis. From this point, the oviduct again narrows and enters the female gland mass near the albumen gland. The three portions of the female gland mass were not well differentiated from T. M. Gosliner & R. C. Willan, 1991 Page 113 Figure 12 Flabellina rubropurpurata Gosliner & Willan, sp. nov. A. Dorsal view of 8 mm living animal. B. Rhinophore, scale = 0.5 mm. C. Jaw, scale = 0.1 mm. D. Reproductive system: am, ampulla; bc, bursa copulatrix; mu, mucous gland; p, penis; rs, receptaculum seminis; vd, vas deferens; scale = 0.1 mm. each other. The female gland mass exits at the female genital aperture, adjacent to the bursa copulatrix. The bursa is spherical and exits via a long, narrow duct. The vas deferens is narrow and enlarges into the thick penis. No distinct prostatic portion of the vas deferens was ob- served. The simple unarmed penis terminates at the male gonopore. Discussion: Based on a single specimen collected from southern Africa, GOSLINER (1987) indicated that the col- oration of this species was distinct from all described spe- cies of Flabellina. The arrangement of cerata, with three rows of cerata in the precardiac peduncle, is similar to that described for F. telja Er. Marcus & Ev. Marcus, 1967, and F. stohleri Bertsch & Ferreira, 1974. Flabellina telja and F. stohleri are similar to each other in external morphology and coloration, and are sympatric within the Gulf of California. These two species are likely synonymous with each other. They differ in their color- ation from F. rubropurpurata. These species are orange with opaque white spots and reddish cerata, whereas F. rubropurpurata has a purple body with reddish cerata. Page 114 The Veliger, Vol. 34, No. 2 Figure 13 Flabellina rubropurpurata Gosliner & Willan, sp. nov., scanning electron micrographs. A. Entire width of radula, Madang, Papua New Guinea, scale = 10 um. B. Entire width of radula, Sodwana Bay, South Africa, scale = 25 um. C. Lateral view of radula, Madang, Papua New Guinea, scale = 10 um. Flabellina telja and F. stohleri have more cerata per row Flabellina rubrolineata (O’ Donoghue, 1929) (up to 6) than F. rubropurpurata (maximum of 4). In- E ternally, the lateral radular teeth of F. telja and F. stohleri (Figures 1E, 15-17) pachsees) Uae denticles than those of F. rubropurpurata. Coryphella ornata RISBEC, 1928, in part:267, variété violacée, The male atrium of F. telja bears numerous papillae, fig. 89, 3; pl. 9, fig. 6. (This taxon has no systematic whereas that of F. rubropurpurata is devoid of any or- status because it was described as a vernacular name, namentation. see discussion). T. M. Gosliner & R. GC. Willan, 1991 Page 115 Figure 14 Flabellina rubropurpurata Gosliner & Willan, sp. nov., scanning electron micrographs. A. Dorsal view of rachidian teeth, Madang, Papua New Guinea, scale = 5 wm. B. Dorsal view of rachidian teeth, Sodwana Bay, South Africa, scale = 10 wm. C. Lateral teeth, Madang, Papua New Guinea, scale = 5 wm. D. Lateral teeth, Sodwana Bay, South Africa, scale = 10 um. Coryphellina rubrolineata O’ DONOGHUE, 1929:798, fig. 219; Flabellina rubrolineata (O’ Donoghue): GOSLINER & GRIF- BaBA, 1955:26, figs. 40, 41, pl. 13, fig. 37; BaBa, 1990: FITHS, 1981:114; WILLAN & COLEMAN, 1984:42, fig. 51, pl. 13, fig. 37. 133; MIENIS & GAT, 1986:683; GOSLINER & KUZIRIAN, Coryphella ornata var. violacea RISBEC, 1953:fig. 98a. syn. 1990:9, fig. 6. nov. Con Lae ee te ea ee ee Distribution: This species is widely distributed in the Coryphella rubrolineata (O’ Donoghue): COLEMAN, 1981b:31, Indo-Pacific tropics where it is known from New Cale- color fig., 100. donia (RIsBEC, 1928), Australia (WILLAN & COLEMAN, Page 116 The Veliger, Vol. 34, No. 2 Figure 15 Flabellina rubrolineata (O’Donoghue, 1929), scanning electron micrographs. A. Jaw, Madang, Papua New Guinea, scale = 150 um. B. Masticatory border, Madang, Papua New Guinea, scale = 40 um. 1984), Japan (BABA, 1955), Papua New Guinea (GOSLINER & KUZIRIAN, 1990; present study), Malaysia (Ho Soon Lin, personal communication), Aldabra Atoll (present study), and the Red Sea (O’ DONOGHUE, 1929; MIENIS & GaT, 1986; Christopher Todd, personal communication). Material: One specimen, California Academy of Sciences, San Francisco, CASIZ 070557, Passe Femme, Aldabra Atoll, Republic of Seychelles, 19 March 1986, T. M. Gos- liner. Four specimens, CASIZ 070547, 070549, 070550, Barracuda Point, Pig Island, Madang, Papua New Guin- ea, 10-27 m depth, 29 January—14 February 1988, T. M. Gosliner. One specimen, CASIZ 070553, Barracuda Point, Pig Island, Madang, Papua New Guinea, 6 October 1986, T. M. Gosliner. Two specimens, CASIZ 070556, SE side of Barracuda Point, Pig Island, Madang, Papua New Guinea, 24.4 m depth, 23 January 1988, J. Mizeu. One specimen, CASIZ 070548, Sek Passage, Madang, Papua New Guinea, 10.7 m depth, 15 October 1986, T. M. Gosliner. One specimen, CASIZ 070551, N side Rasch Pass, Madang, Papua New Guinea, 18.3 m depth, 16 February 1988, T. M. Gosliner. Three specimens, CASIZ 070552, the Quarry, 30 km N of Madang, Papua New Guinea, 30.5 m (maximum) depth, 11 February 1988, T. M. Gosliner. Three specimens, CASIZ 070554, Kranket Wall, E side of Kranket Island, Madang, Papua New Guinea, 30.5 m depth, 4 February 1988, R. C. Willan. One specimen, CASIZ 070555, near lighthouse, Madang, Papua New Guinea, 12.2 m depth, 17 October 1986, T. M. Gosliner. One specimen, “The Nursery,” N side of Julian Rocks, off Cape Byron, New South Wales, Australia, 6 m depth, 12 July 1980, R. C. Willan. Two specimens, in channel between main islands, Shag Rocks, off Point Lookout, North Stradbroke Island, Queensland, Australia, 13 m depth, 5 August 1980, R. C. Willan. Two specimens, base of Heron Bommie, W side Heron Island, Capricornia Group, Great Barrier Reef, Queensland, Australia, 10 m depth, 13 November 1980, R. C. Willan. External morphology: The living animals (Figure 1E) reach 42 mm in length. The coloration is variable, even within a population from a single locality. The general body color is translucent pinkish white. Varying amounts of opaque white may be present on the sides of the body and notum. Three purple or reddish longitudinal lines extend from the head to the posterior limit of the tail. One of these is middorsal and extends from the anterior border of the head to the tail. A lateral line runs below the notum along either side of the body. Purple pigment may also be present on the distal third of the oral tentacles, on the apices of the foot corners, on the apices of the rhinophores, and on the cerata. The anterior face of the rhinophores is the same color as the body. Their posterior surface, where the papillae are situated, is opaque white or yellow. The cerata are translucent white or opaque white basally with red, purple, or yellow pigment on the distal portion. In one specimen from Papua New Guinea, the entire surface of the cerata was red. The body is narrow and elongate. The notum is high and well developed and its brim undulate, widening at the level of each ceratal group. The oral tentacles are thin and T. M. Gosliner & R. C. Willan, 1991 Page 117 Figure 16 Flabellina rubrolineata (O’ Donoghue, 1929), scanning electron micrographs. A. Rachidian and lateral teeth, Madang, Papua New Guinea, scale = 30 wm. B. Dorsal view of rachidian teeth, Madang, Papua New Guinea, scale = 10 um. C. Ventral view of rachidian tooth, Madang, Papua New Guinea, scale = 10 um. D. Lateral teeth, Madang, Papua New Guinea, scale = 10 um. cylindrical in cross section, longer than the rhinophores. The rhinophores are elongate with an acute apex. The posterior surface is ornamented with approximately 100 elongate papillae. The anterior foot corners are elongate and tentacular. The cerata are variable in length and may be short and bulbous or elongate and cylindrical. The cerata are arranged in 5 or 6 distinct groups, each elevated from the notum. The precardiac cluster consists of 3 or 4 distinct rows of cerata, with 1-3 cerata per row. The first 3 or 4 postcardiac groups are arranged in arches consisting of 3-6 cerata per arch. The posterior 1 or 2 clusters consist of only 1 or 2 cerata. The gonopore is situated ventral to the 2 posterior ceratal rows of the precardiacl ceratal group. The pleuroproctic anus is located in the interhepatic space, below the notum. The nephroproct is immediately antero- dorsal to the anus, but still below the notal brim. Page 118 50 Figure 17 Flabellina rubrolineata (O’Donoghue, 1929). Reproductive sys- tem: al, albumen gland; am, ampulla; bc, bursa copulatrix; me, membrane gland; mu, mucous gland; p, penis; pr, prostate; rs, receptaculum seminis; v, vagina; scale = 0.5 mm. Buccal mass: The muscular buccal mass is ovoid and occupies the portion of the body cavity anterior to the rhinophores. The large ramified oral glands emanate from the anterior portion of the buccal mass and extend pos- teriorly along the mass and into the notal expansions of the precardiac ceratal cluster. The jaws (Figure 15A) are well developed and thick. The masticatory border (Figure 15B) is broad and elongate, bearing 5-7 rows of denticles. The radula (Figure 16A) has a formula of 29-30 x 1- 1-1- in three specimens examined. The rachidian teeth (Figure 16B, C) are broad, with a wide arch between the posterior limbs. The posterior end of either limb has an articulatory appendage on its outer side. The cutting edge of the rachidian teeth has 7 or 8 denticles on either side of the more elongate central cusp. The central cusp is depressed below the level of the adjacent denticles. The lateral teeth (Figure 16D) are broadly triangular with an elongate, curved basal limb. There are 7 or 8 acutely pointed denticles along the inner margin of the laterals. The outer side of the teeth bears 4 or 5 irregular striations. Reproductive system (Figure 17): The arrangement of the organs is triaulic. The preampullary duct is narrow and elongate. It expands into a wide, saccate ampulla, which again narrows and divides into the oviduct and vas deferens. After a short distance, the oviduct gives rise to two distinct pyriform receptacula seminis. From this point the oviduct continues towards the gonopore and enters the albumen gland portion of the female gland mass. The membrane gland is situated adjacent to the albumen gland. Most of the female gland mass is formed by the various lobes of the mucous gland. From the point where the oviduct enters the female gland mass, a vaginal duct ex- tends to its own aperture, adjacent to the penis. A minute bursa copulatrix is present adjacent to the vaginal pore. The opening of the mucous gland is immediately ventral The Veliger, Vol. 34, No. 2 to the vaginal pore. The vas deferens expands into a short prostatic portion, which widens again at the conical, un- armed penial papilla. Discussion: When it was described, Coryphellina O’ Don- oghue was monotypic, its type species being Coryphellina rubrolineata O’Donoghue, 1929. Coryphellina has been considered as a junior synonym of Coryphella Gray, 1850, by MILLER (1971). GOSLINER & GRIFFITHS (1980) con- sidered both of these genera as junior synonyms of Fla- bellina Voigt, 1834. This view has been widely accepted, and is further supported by GOSLINER & KUZIRIAN’s recent (1990) cladistic analysis of the family. The systematic status of Flabellina rubrolineata (O’ Don- oghue, 1929) has recently been revised by GOSLINER & KUZIRIAN (1990). Specimens identified by Ev. MARcus & Er. Marcus (1961, 1970) from Brazil and the Gulf of California have been shown to represent a distinct species, Flabellina marcusorum Gosliner & Kuzirian, 1990, and F. rubrolineata is restricted to the Indo-Pacific tropics. Flabellina rubrolineata is morphologically similar to specimens described by RIsBEC (1928, 1953) from New Caledonia. In the discussion of F. bicolor, in the present work, difficulties with the systematic status of Risbec’s Coryphella ornata were resolved. GOSLINER (1980) dis- cussed the status of Risbec’s “‘variété violacée”’ of F. ornata, noting that it appeared to be distinct from F. ornata. Its triseriate radula, with denticulate lateral teeth, clearly es- tablish its placement within the genus Flabellina. RISBEC’s (1928:pl. 9, fig. 6) description of the color of the violet variety of F. ornata indicates that the animal is rose violet with three longitudinal red lines. This pattern is identical to that described for F. rubrolineata. The rhinophores are described as perfoliate only on the posterior side with very long lamellae. We interpret this as meaning papillate rath- er than perfoliate rhinophores. The radular morphology of this variety of F. ornata (RISBEC, 1928:fig. 89, 3) is virtually identical to that depicted by BABA (1955:fig. 41c) for F. rubrolineata. It is apparent that these two species are synonymous. However, the /nternational Code of Zoological Nomenclature states that vernacular names have no systematic status. Thus, Risbec’s 1928 taxon cannot have priority over Cory- phellina rubrolineata O’ Donoghue, 1929. It appears that Coryphella ornata var. violacea Risbec, 1953, constitutes a validly described subspecies. Nevertheless, it is here con- sidered a junior subjective synonym of Flabellina rubroline- ata (O’Donoghue, 1929) due to priority of publication. Species of Flabellina with papillate rhinophores and a triaulic reproductive system are compared in Table 2. Flabellina exoptata Gosliner & Willan, sp. nov. (Figures 1F, 18-20) Distribution: This species has been found from Enewetak, Marshall Islands (Scott Johnson, personal communica- T. M. Gosliner & R. C. Willan, 1991 Table 2 Morphological variation in Flabellina species with elongate papillae on rhinophores. Species Color delicata Ceratal arrangement all arches Radular formula S31 eA Denti- cles on either side of rachid- lan 6-9 Denti- cles on lateral 15-18 Receptac- ulum seminis bilobed Bursa copulatrix reduced Page 119 Vas deferens short body reddish purple, rhino- phores red, cerata with opaque white & yellow & opaque white band body pinkish- purple, rhino- phores red with yellow spots, cerata with purple & white bands body pink, cera- ta, rhinophores & oral tenta- cles purple & white body translucent white with red cerata, purple spots on head body whitish or purple; 3 lon- gitudinal red or purple lines exoptata preanal arch, postanal rows marcusorum all arches Gosliner & Kuzirian, 1990 poenicia (Burn, 1957) rubrolineata all arches (0’ Donoghue, 1929) tion), Guam (Clay Carlson and Patty Jo Hoff, personal communication), Fiji (present study), Queensland, Aus- tralia (present study), Western Australia (Neville Cole- man, personal communication), Papua New Guinea (pres- ent study), Malaysia (Ho Soon Lin, pesonal communication), and Aldabra Atoll (present study). Etymology: The epithet exoptata means ‘“‘much desired” and refers to the strikingly beautiful color of this species. Type material: Holotype, CASIZ 070988, Planet Rock, 10 km S of Madang, Papua New Guinea, 24.4 m (max- imum) depth, 19 January 1988, T. M. Gosliner. One paratype, CASIZ 070979, Passe Femme, Aldabra Atoll, Seychelles, 0.5 m depth, 12 March 1986, T. M. Gosliner. Eight paratypes, CASIZ 070980, 2 dissected, Passe Femme, Aldabra Atoll, Seychelles, 17 March 1986, T. M. Gosliner. One paratype, CASIZ 070978, Passe Femme, Aldabra Atoll, Seychelles, 17 March 1986, T. M. Gosliner. Two paratypes, USNM 859084, Passe Femme, Aldabra Atoll, Seychelles, 17 March 1986, T. M. Gosliner. One paratype, CASIZ 070981, dissected, Madang, Papua 23-37 27-34 all arches 34 30-32 x ‘1-1 13-20 bilobed absent short ‘1-1 5-8 bilobed well developed, stalked elongate scl G=7) sh = = — -1-1 7-10 bilobed reduced short New Guinea, 4 October 1986, J. Darr. Two paratypes, CASIZ 070982, N end Rasch Pass, Madang, Papua New Guinea, 18.3 m depth, 6 October 1986, T. M. Gosliner. One paratype, CASIZ 070983, lighthouse, Madang, Pa- pua New Guinea, 18.3 m depth, 17 October 1986, M. T. Ghiselin. Two paratypes, CASIZ 070984, lighthouse, Ma- dang, Papua New Guinea, 15.2 m depth, 21 October 1986, T. M. Gosliner. One paratype, CASIZ 070985, Anemone Reef, E of Riwo Island, Madang, Papua New Guinea, 13.7 m depth, 10 January 1988, T. M. Gosliner. One paratype, CASIZ 070986, lighthouse, Madang, Papua New Guinea, 33.5 m depth, 15 January 1988, T. M. Gosliner. Two paratypes, CASIZ 070987, the Blowhole, approxi- mately 1 km S of Cape Croiselles, N of Madang, Papua New Guinea, 24.4 m depth, 18 January 1988, T. M. Gosliner. One paratype, AMS C164085, coral rubble, the Quarry, near Bunu Village, 30 km N of Madang, Papua New Guinea, 3-5 m depth, 21 January 1988, R. C. Wil- lan. Two paratypes, CASIZ 070989, lighthouse, Madang, Papua New Guinea, 7.6 m average depth (27.4 m max- imum), 22 January 1988, T. M. Gosliner. One paratype, Page 120 The Veliger, Vol. 34, No. 2 Figure 18 Flabellina exoptata Gosliner & Willan, sp. nov. A. Dorsal view of 21 mm living animal. B. Lateral view. C. Rhinophore, scale = 1.0 mm. D. Reproductive system: al, albumen gland; am, ampulla; mu, mucous gland; p, penis; rs, receptaculum seminis; v, vagina; scale = 0.5 mm. CASIZ 060991, Barracuda Point, Pig Island, Madang, Papua New Guinea, 7.6 m depth, 7 February 1988, T. M. Gosliner. One paratype, AMS C164084, coral rubble, patch reef 1 km S Lian Island, 15 km SE of Port Moresby, Papua New Guinea, 10 m depth, D. J. Brunkhorst, 17 June 1988. One paratype, CASIZ 070992, Barracuda Point, Pig Is- land, Madang, Papua New Guinea, 25 m depth, 16 July 1989, T. M. Gosliner. One paratype, AMS C164083, feeding on Halocordyle disticha, on vertical wall of a bommie, ““The Canyons,” SE side of Heron Island, Capricornia Section, Great Barrier Reef, Queensland, Australia, 10 m depth, 20 August 1981, M. Ready. External morphology: The living animals reach 30 mm in length. The general body color is deep pinkish purple. Basally, the oral tentacles are the same color as the rest of the body. Their middle third is deep purple and the outer third is generally opaque cream yellow. However, in some specimens from Aldabra Atoll, there is no opaque pigment on the outer portion of the tentacles and they are the same color as the rest of the body. Purple pigment is also present on the apical portion of the foot corners. The rhinophores are vivid orange with yellow pigment on the apices of the rhinophoral papillae. The basal half to two- thirds of the cerata is pinkish purple. Above this section, a deep purple ring is present. The apical portion of the cerata is opaque cream yellow. T. M. Gosliner & R. C. Willan, 1991 Figure 19 = Flabellina exoptata Gosliner & Willan, sp. nov., scanning electron micrographs. A. Jaw, Aldabra Atoll, scale = 200 um. B. Masticatory border, Aldabra Atoll, scale = 30 um. The body is stockier than other members of the genus (Figure 18A). The notal brim is expanded at the level of each ceratal group, but is otherwise reduced compared to Flabellina rubrolineata. The oral tentacles are cylindrical throughout their length and they taper to an acute apex. The rhinophores (Figure 18B) are thick basally, and ter- minate in a distinctly pointed apex. The posterior side of each rhinophore bears over 120 densely packed, elongate papillae. The foot corners are elongate and tentacular, and are generally recurved posteriorly when the animal is ac- tively crawling. The cerata are thick and cylindrical for most of their length, but taper to an acute apex. The cerata are slightly elevated from the notum on a common pedun- cle. The cerata are arranged in distinct rows. The pre- cardiac ceratal cluster consists of three distinct rows, with 1-3 cerata per row. The postcardiac cerata are arranged in 4 or 5 linear rows that are well separated from each other. The anterior postcardiac row contains the most cera- ta (3-5). The more posterior rows contain fewer cerata, and the posteriormost row consists of only a single ceras. The gonopore is situated ventral to the second and third ceratal rows on the right side of the body. The pleuroproctic anus is located below the notum within the interhepatic space. The nephroproct is immediately anterodorsal to the anus. Buccal mass: The muscular buccal mass occupies the an- terior portion of the body, from the rhinophores to the anterior end of the head. The narrow ducts of the paired oral glands emanate from the anterior end of the buccal mass. These glands are highly ramified and extend pos- teriorly into the peduncle of the anteriormost ceratal clus- ter. The chitinous jaws (Figure 19A) are elongate and broad. The masticatory border (Figure 19B) bears several rows of elongate denticles. The denticles of the outermost row are longest. The radular formula is 23-37 x 1-1-1- in the two specimens examined. The rachidian teeth are narrow and elongate. The posterior limit of each limb bears a peduncle for attachment to the following tooth. The cutting edge of the teeth bears 7-10 elongate denticles on either side of the elongate, acutely pointed central cusp. The central cusp is depressed below the level of the adjacent denticles. The lateral teeth are triangular with a broad base and an elon- gate, acutely pointed primary cusp. There are 13-20 mi- nute, acutely pointed denticles along the inner margin of the tooth. Reproductive system (Figure 18D): The preampullary duct is narrow and elongate. It expands into an elongate, curved ampulla. The ampulla narrows again and divides into the oviduct and vas deferens. The oviduct is narrow and elongate and expands to join the two large receptacula seminis. The inner receptaculum is distinctly larger than the one closer to the female gland mass. The oviduct again narrows and enters the female gland mass near the small albumen gland. The albumen and membrane glands are much smaller than the mucous gland, which comprises the bulk of the reproductive system. The distinct vaginal duct continues from the oviduct to its own aperture, adjacent to the penis. The vagina is expanded for most of its distal portion, but a distinct bursa copulatrix is absent. The vas Page 122 The Veliger, Vol. 34, No. 2 Figure 20 Flabellina exoptata Gosliner & Willan, sp. nov., scanning electron micrographs. A. Rachidian and lateral teeth, Madang, Papua New Guinea, scale = 30 um. B. Rachidian and lateral teeth, Aldabra Atoll, scale = 15 um. C. Lateral teeth, Madang, Papua New Guinea, scale = 10 um. D. Lateral teeth, Aldabra Atoll, scale = 10 um. deferens is short but expands into a small prostatic seg- ment. The prostatic portion expands further into the broad penial sac containing the simple, unarmed penis. Discussion: Its unique color pattern readily distinguishes Flabellina exoptata from three other described species of Flabellina with papillate rhinophores, Flabellina rubroline- ata, F. poenicia (Burn, 1957), and F. marcusorum Gosliner & Kuzirian, 1990. All these species have the cerata of the postcardiac groups arranged in horseshoe-shaped arches, whereas those of F. exoptata are in simple, linear rows. In Flabellina marcusorum, the bursa copulatrix is large and obvious, whereas in F. rubrolineata and F. delicata it is reduced, and in F. exoptata it is entirely absent. The reproductive system of FP. poenicia remains unknown. The vas deferens is shorter in F. exoptata than in F. rubrolineata and F. marcusorum. In coloration, Flabellina exoptata is most similar to F. T. M. Gosliner & R. C. Willan, 1991 Page 123 5D Figure 21 Flabellina delicata Gosliner & Willan, sp. nov. A. Dorsal view of 16 mm living animal. B. Rhinophore, scale = 1.0 mm. C. Jaw, scale = 0.2 mm. D. Reproductive system: al, albumen gland; am, ampulla; bc, bursa copulatrix; me, membrane gland; mu, mucous gland; p, penis; rs, receptaculum seminis; v, vagina, scale = 1.0 mm. E. Ceras, scale = 1.0 mm. marcusorum, but this species lacks the yellow pigment on the posterior surface of the rhinophoral papillae, which is present in F. exoptata. In addition, F. marcusorum has opaque white pigment on the posterior end of the foot, which is not present in F. exoptata. This species has been erroneously identified as Flabellina macassarana Bergh, 1905, on a Malaysian postage stamp. However, F. macassarana differs from F. exoptata in sev- eral important aspects. The color of F. macassarana is pinkish yellow without the striking purple and yellowish bands that distinguish F. exoptata. Also, F. macassarana has perfoliate rather than papillate rhinophores. The shape and denticulation of the radular teeth differ markedly be- tween the two species. Flabellina macassarana has only 20 rows of teeth in the radula, whereas F. exoptata has 23- 37 rows. Both the rachidian and lateral teeth of F. ma- cassarana have far fewer denticles than do the teeth of F. exoptata. Therefore, F. exoptata can be clearly distin- guished from F. macassarana. Flabellina macassarana is known only from Bergh’s original description and the unique holotype could not be located in the in the Zoolo- gisch Museum, Amsterdam (R. Moolenbeek, personal Page 124 The Veliger, Vol. 34, No. 2 Figure 22 Flabellina delicata Gosliner & Willan, sp. nov., scanning electron micrographs. A. Masticatory border, Madang, Papua New Guinea, scale = 40 um. B. Entire width of radula of holotype, Madang, Papua New Guinea, scale = 40 um. C. Entire width of radula, Aliwal Shoals, South Africa, scale = 20 um. D. Lateral view of rachidian teeth of holotype, Madang, Papua New Guinea, scale = 10 um. communication). Determination of its relationship to other members of the genus requires further study and elabo- ration of the original description. Flabellina delicata Gosliner & Willan, sp. nov. (Figures 1G, 21-23) Coryphellina sp.: GOSLINER, 1987:114, fig. 224. Distribution: Flabellina delicata is known from Papua New Guinea (present study) and from Natal, South Africa (GOSLINER, 1987, and present study). Etymology: The epithet delicata refers to the elongate, graceful body form of this species. Type material: Holotype: California Academy of Sci- ences, CASIZ 070999, the Quarry, approximately 1 km S of Cape Croiselles, Madang, Papua New Guinea, 30.5 m (maximum) depth, 11 February 1988, T. M. Gosliner. Paratypes: One specimen, CASIZ 071000, the Quarry, approximately 1 km S of Cape Croiselles, Madang, Papua New Guinea, 10.4 m depth, 19 February 1988, T. M. Gosliner. One specimen, South African Museum, Cape Town, SAM A35719, dissected, Aliwal Shoals, off Scott- burgh, Natal, South Africa, 12.2 m depth, 2 May 1982, T. M. Gosliner. T. M. Gosliner & R. C. Willan, 1991 Page 125 Figure 23 Flabellina delicata Gosliner & Willan, sp. nov., scanning electron micrographs, scales = 10 wm. A. Dorsal view of rachidian teeth of holotype, Madang, Papua New Guinea. B. Dorsal view of rachidian teeth, Aliwal Shoals, South Africa. C. Lateral teeth of holotype, Madang, Papua New Guinea. D. Lateral teeth, Aliwal Shoals, South Africa. External morphology: The living animals (Figure 1G) are 15-20 mm in length. The general body color is deep reddish purple. Generally, the oral tentacles are a deeper purple than the rest of the body. The rhinophores are deep red throughout. The cerata are translucent white basally, with the opaque white digestive gland giving the cerata an overall white appearance. Near the middle of each ceras, an opaque white transverse band is present on its surface. More distally, the ceras is again translucent and a golden- yellow-orange enlarged portion of the digestive gland is visible. A subapical transverse ring of translucent purple is present just below the translucent white apex. The body is narrow and delicate in appearance (Figure 21A). The notal brim is slightly expanded at the base of the cerata, but is otherwise reduced. The oral tentacles are slender and elongate, terminating at an acute apex. The rhinophores (Figure 21B) are elongate and slender with approximately 30 well-separated papillae on their poste- rior surface. The rhinophores terminate at an acute apex. The tentacular foot corners are elongate and acutely point- ed. The numerous cerata are slender and cylindrical throughout their length (Figure 21E). The cerata are ar- ranged in distinct, well-separated clusters. The precardiac cluster contains 3 or 4 distinct rows with 1-6 cerata per row. The postcardiac clusters are arranged in 5-8 horse- shoe-shaped arches. The anteriormost arch contains 6-10 Page 126 The Veliger, Vol. 34, No. 2 Table 3. Morphological variation in Flabellina. 0 = ancestral; 1-3 = derived states; 9 = missing data. rhino- phores anus ceratal peduncles preanal Species cerata j=) N ancestor affinis albomarginata baba baetica bertschi bicolor bilas delicata engelt exoptata funeka ischitana marcusorum pedata pellucida poenicia r1wo rubrolineata rubropurpurata telja NNEBENP SP RP ENNENENNRP PNK NE NY COONDDOCDODCCORPONNOORKR OOO OW BP REPNEPNDTONKFPENKPNRPRPONHENE PNNNNNNNNNNNNNNNNNNND = character number cerata. More posterior arches contain fewer cerata. The posteriormost arch contains 1-3 cerata. The gonopore is situated ventral to the posterior 2 rows of the precardiac ceratal cluster. The pleuroproctic anus is situated in the interhepatic space, ventral to the edge of the notum. The nephroproct is immediately anterodorsal to the anus. Buccal mass: The buccal mass is small relative to the rest of the body. The narrow ducts of the paired oral glands emanate from the anterior portion of the buccal mass. The jaws (Figure 21C) are broad and ovoid. The masticatory border (Figure 22A) bears 5 or 6 rows of small denticles. The outermost row bears the longest denticles. The radular formula is 31 x 1-1-1- in two specimens examined. The rachidian teeth (Figures 22B-D, 23A, B) are broad with short lateral limbs. There are 6-9 elongate, acute denticles on either side of the elongate central cusp. The central cusp is depressed below the level of the adjacent denticles (Figure 22D). The lateral teeth (Figure 23C, D) are triangular with a relatively broad base. The primary cusp is narrow and elongate. There are 15-18 minute denticles along most of the inner margin of the laterals. Reproductive system (Figure 21D): The narrow pream- pullary duct curves and widens into the saccate ampulla. The ampulla curves, narrows, and divides into the oviduct and vas deferens. The short oviduct joins with the two receptacula seminis, which are approximately equal in size. The oviduct continues for a short distance and enters receptac- repro- oral central ulum bursa foot ductive glands cusp seminis copulatrix corners system NO CO a a a oe a ee eee ee Te oe Tee oe DRDNNINWNNNNUONNNNNWNNN DNDN LY a QOONnNvUDOCOQCoqQoqooqoqo°ocOorRrKY OCC OCF OO COOrFPrFPUOONCOONNRKP RP ONNNN OO Oo PP ee ee ee ee ee eee ee ee ee oorowoqcorcjororoqooo°ocqco°c”je = fo) the albumen gland. The albumen and membrane glands are adjacent to each other and are much smaller than the voluminous mucous gland. From the entrance of the ovi- duct into the female gland mass, the vaginal duct continues distally towards its own aperture adjacent to the penis. The vagina gives rise to a small bursa copularix imme- diately prior to exiting at the vaginal pore. The vas deferens is short and straight and appears to be prostatic nearest the ampulla. It is uniform in diameter for most of its length and is contiguous with the simple, unarmed penial papilla. Discussion: By means of its unique color pattern, Flabel- lina delicata can be distinguished from other members of the genus with papillate rhinophores. Its notal brim is more reduced than F. rubrolineata, as in F. marcusorum and F. exoptata. The papillae on the rhinophores are fewer in number and sparser in arrangement than in the other species that possess papillae. The postcardiac ceratal clus- ters are arranged in horseshoe-shaped arches as in F. rubro- lineata and F. marcusorum rather than in linear rows as in F. exoptata. However, F. delicata has more cerata per cluster than do the other species. The rachidian radular teeth of Flabellina delicata are broader relative to their length than in F. rubrolineata, F. marcusorum, or F. exoptata. Only F. exoptata and F. de- licata have numerous denticles on the cutting edge of the lateral teeth. The reproductive system of Flabellina delicata is most similar to F. rubrolineata. Both species have a reduced bursa T. M. Gosliner & R. C. Willan, 1991 Page 127 Table 3 Continued. rhino- receptac- number of _ phoral ceratal rhino- penial denticles anterior ulum lateral teeth laterals papillae groups phores warts on lateral notal brim prostate liver arch — seminis 0 1 (0) 0 0 0 0 0 0 0 0 0 1 0 0 1 0 0 1 1 0 0 0 1 1 0 0 0 0 (0) 0 0 1 0 1 0 0 2 0 0 1 (0) 0 0 1 1 1 0 0 0 0 0 0 1 0 0 1 0 0 0 0 0 0 0 0 1 0 1 0 0 2 0 0 1 (0) 0 0 0 1 0 0 2 0 0 1 0 0 0 0 1 2 0 0 0 1 1 (0) 1 1 0 1 0 0 2, 0 0 1 0 0 0 0 1 2 1 0 0 1 1 0 1 1 0 1 0 0 1 0 0 1 1 0 0 1 1 0 0 1 0 0 1 1 0 0 0 1 2 0 0 0 0 1 0 1 1 0 1 0 0 0 0 0 0 0 0 1 1 1 0 0 0 0 0 0 0 0 0 0 1 2 0 0 0 0) 0 0 1 9 0 1 0 0 2 0 0 1 0 0 0 0 1 2, 0 0 0 0) 0 0 1 1 0 1 0 0 2 0 0 1 0 0 0 0 1 0 0 2, 1 0) 1 0 0 0 11 12 13 14 15 16 7/ 18 19 20 21 copulatrix. However, the vas deferens is shorter and straighter in F. delicata than in F. rubrolineata. Three other distinct species have sparsely papillate rhi- nophores, Flabellina albomarginata Miller, 1971, F. baetica Garcia Gomez, 1984, and Flabellina sp. 1 (GOSLINER, 1987). These species differ from the above-mentioned taxa in several significant regards. The papillae on the rhino- phores are less well developed, the cerata are arranged in simple crowded rows (except in F. baetica), and the re- productive system is diaulic rather than triaulic. DISCUSSION The phylogenetic and systematic relationships of the Fla- bellinidae have recently been examined by GOSLINER & KUZIRIAN (1990). From their analysis, it is apparent that the genus Flabellina contains numerous, morphologically diverse species. Included in the genus are some of the most primitive aeolids, such as F. islandica (Odhner, 1937), as well as intermediate and highly derived taxa. They con- cluded that the most highly derived taxa formed two dis- tinct clades. All of the taxa included in the present study are members of these two clades. In members of both of these clades, digitate oral glands and a depressed central cusp of the rachidian tooth are present. The first of these clades includes taxa with cerata elevated on distinct pe- duncles and densely annulate or perfoliate rhinophores. The second clade contains taxa with a bilobed receptacu- lum seminis, and most members of this clade also possess papillae ornamenting the posterior face of the rhinophores. In order to examine further the phylogeny of members of these two clades of derived flabellinids, the morphology of the taxa described here was examined and the mor- phology of previously described flabellinids was reviewed and, in several cases, re-examined. Eight additional char- acters, not included in the previous study, were examined here. These data are compiled in Table 3. Character Polarity Twenty-one characters of 20 taxa were included. The polarity of these characters was determined using out- group comparison of less derived flabellinids (see GOSLINER & KuZIRIAN, 1990). The basis for determining polarity of these features is discussed below. The sequence of char- acters is identical to that presented in Tables 3 and 4. 1. Ceratal peduncles: Outgroups of flabellinids and spe- cies of Notaeolidia have the cerata arranged in linear rows. These rows emerge from epithelial tissue that is at the same level as the rest of the notum. In more derived taxa, the ceratal clusters emerge from stalked clusters, which are well elevated from the notum. These may contain compound ceratal clusters or simple ones. 2. Preanal ceratal rows: Species of less derived flabellin- ids, including all of the taxa not included in this study (outgroup taxa), have several rows of cerata anterior to Page 128 The Veliger, Vol. 34, No. 2 Table 4 Coding for characters in Table 3. 1. ceratal peduncles 1 = low 2. preanal cerata 0 = 3-4 rows 3. rhinophores 0 = simple 4. anus 1 = posterior 5. oral glands 0 = absent 6. central cusp 2 = depressed 7. receptaculum seminis 0 = semiserial 8. bursa copulatrix 0 = stalked 9. foot corners 0 = rounded 10. reproductive system 0 = diaulic 11. lateral teeth 0 = denticulate 12. number of laterals 0 = more than 1 13. rhinophoral papillae O = short 14. ceratal groups 0 = all arches 15. rhinophores O = no rings 16. penial warts 0 = absent 17. lateral denticles 0 = few 18. notal brim O = present 19. prostate 0 = uniform 20. anterior liver arch 0 = absent 21. receptaculum seminis O = single the anus, which form a distinct ceratal cluster. In some derived species that have cerata elevated on peduncles, the number of anterior ceratal rows is reduced. In the most highly derived species (e.g., Flabellina bicolor, F. riwo, and F. bilas), there is only a single ceratal row per peduncle in both the preanal and postanal ceratal clusters. 3. Rhinophores: In most ancestral flabellinids the rhino- phores are simple, without any ornamentation. GOSLINER & KUZIRIAN (1990) have shown that this appears to be the case in the least derived members of the family. Or- namented rhinophores have evolved independently within different lineages of the family. Within the more highly derived members of the family studied here the rhinophores may be simple, ringed (annulate or perfoliate), or papillate. The simple condition is considered to represent the an- cestral state. Ringed and papillate rhinophores have prob- ably both evolved directly from simple ones, though the sequence of changes is uncertain. Owing to the lack of certainty of the evolutionary sequence of derived states, this character is treated as unordered in the present anal- ysis. 4. Anus: In the Notaeolidiidae and less derived members of the Flabellinidae, the anus is situated in the pleuro- proctic position, and is located in the posterior half of the body. In more derived taxa, the anus is situated near the middle of the most anterior postanal ceratal cluster. In all of the taxa examined here, the anus is situated within the interhepatic space, which represents the most derived con- dition within the family. 5. Oral glands: GOSLINER & KUZIRIAN (1990) suggested that an absence of oral glands represents the ancestral state = elevated = 2 rows = ringed = interhepatic = present elevated serial 2 = absent = reduced 2 = absent = tentacular 2, 1 2 = one row 1 2 1 3 1 1 1 1 = triaulic 1 1 1 1 1 1 1 0 1 1 1 2 = papillate ll = smooth =1 = elongate = posterior rows = annulate = present = many = absent = constricted = present = bilobed 2 = perfoliate within the Flabellinidae, because oral glands are also ab- sent in the Notaeolidiidae. Most primitive members of the Flabellinidae lack oral glands, with the exception of Fla- bellina salmonacea (Couthoy, 1838), which has a pair of ventral pyriform oral glands. In all of the taxa studied here, the oral glands are highly ramified, are found dor- sally, and extend to the bases of the preanal ceratal cluster. Even in cases where the glands were not specifically de- scribed, such as in Flabellina ischitana Hirano & Thomp- son, 1990, they are evident in photographs of the living animal (HIRANO & THOMPSON, 1990:fig. 1). 6. Central cusp of the rachidian teeth: All of the less derived members of the Flabellinidae possess rachidian teeth of the radula with a central cusp that is above, or at the same level as, the adjacent denticles. This feature is especially evident when the teeth are viewed laterally. In almost all derived species, the central cusp is depressed below the level of the adjacent denticles. In two species examined in this study, Flabellina riwo and F. bicolor, the central cusp is elevated. This is considered to be a sec- ondarily derived reversal of the depressed cusp within the in-group studied here. This assumption is based upon the highly derived nature of all other aspects of the morphology of these species. 7. Receptaculum seminis: EDMUNDS (1970) described two forms of the receptaculum seminis in aeolid nudi- branchs. A serial arrangement has two distinct ducts en- tering the receptaculum, while a semiserial configuration has only a single duct entering the receptaculum. Edmunds considered the former to be the ancestral condition within the aeolids. This appears to be the case in Notaeolidia T. M. Gosliner & R. C. Willan, 1991 (WAGELE, in press), and was considered to represent the ancestral condition within the Flabellinidae (GOSLINER & KuzIRIAN, 1990). The majority of more derived species of flabellinids have a semiserial receptaculum. Some of the derived members studied here also possess a serial recep- taculum. This is considered to be a secondarily derived reversal to a serial receptaculum from a semiserial con- dition. In one instance, in Flabellina riwo, the receptacu- lum is entirely absent. This is considered to be a further modification of the secondarily derived serial configuration. 8. Bursa copulatrix: The presence of a stalked bursa is considered to represent the ancestral state in the Aeolidacea (EDMUNDS, 1970). This plesiomorphic condition exists in the majority of the Flabellinidae (GOSLINER & KUZIRIAN, 1990). In other taxa, the bursa may be reduced in size and sessile, or it may be entirely absent. Both of these arrange- ments are considered derivations of the primitive state. It is difficult to place the derived states in a linear configu- ration, because loss of the bursa may not require reducing the bursa prior to loss. For this reason this character is treated as unordered. 9. Foot corners: A simply rounded anterior end of the foot is present in Notaeolidia (WAGELE, in press) and in two primitive species of Flabellina (GOSLINER & KUZIRIAN, 1990), F. islandica and F. salmonacea. Possession of ten- tacular foot corners represents a derived state within the Flabellinidae. This apomorphic condition is present in all of the taxa examined in this study. 10. Reproductive system: GHISELIN (1966) argued that, in opisthobranchs, an androdiaulic reproductive system preceded a triaulic arrangement of organs. The vast ma- jority of flabellinids have an androdiaulic reproductive sys- tem. However, a few species, which are highly apomorphic in other aspects of their anatomy, have a triaulic arrange- ment of reproductive organs. This is considered to rep- resent an apomorphic feature within the flabellinids, and appears to be the case throughout the Opisthobranchia. 11. Lateral teeth: In species of Notaeolidia (WAGELE, in press) and in most species of Flabellina, the lateral radular teeth bear a series of denticles along their inner edge. In a few species of Flabellina studied here, the laterals are smooth and entirely devoid of denticles. In F. ischitana, a few reduced denticles may be present or entirely lacking in different individuals (HIRANO & THOMPSON, 1990). The absence of denticles on the lateral teeth is considered to represent a derived feature within Flabellina. 12. Number of lateral teeth: In species of Notaeolidia (WAGELE, in press) there is a variable number (3-5) of lateral radular teeth on either side of the rachidian. In Flabellina islandica there are two rows of laterals on either side of the rachidian. In the remainder of Flabellina species, there is only a single lateral tooth on either side of the rachidian. This is considered the derived state within the genus. Page 129 13. Rhinophoral papillae: In some species of Flabellin- idae, Facelinidae, and Aeolidiidae, the posterior surface of the rhinophores bears numerous papillae. It is clear that this condition has arisen independently within these lin- eages of aeolids and represents a derived feature within each of these families. Within the Flabellinidae, some taxa have simple rounded papillae while others have elongate digitiform ones. On a functional basis, more elongate pa- pillae probably arose from simply rounded ones. The de- rived condition provides greater surface area for chemo- sensory reception. 14. Ceratal groups: In a few species of flabellinids, the cerata are arranged in horseshoe-shaped arches, in a fash- ion similar to that described for the Favorininae (see EDMUNDs, 1970). A reduction of the postanal arches to linear rows represents a derived condition found only in Flabellina exoptata. 15. Rhinophoral rings: Most opisthobranchs utilize their rhinophores as their primary chemosensory organs. The Flabellinidae and other aeolidacean taxa include species with smooth and ornamented rhinophores. Smooth rhino- phores provide less sensory surface area and are considered to represent the ancestral condition, based on functional criteria. The least derived members of Flabellinidae, Eu- branchidae, Tergipedidae, and Aeolidiidae have smooth rhinophores. In derived species, the rhinophores are gen- erally ornamented with either papillae (see above), well separated annulations or densely packed lamellae (perfo- liate rhinophores). All of these conditions exist within the Flabellinidae. Judging from the cladogram presented by GOSLINER & KUZIRIAN (1990), it appears that annulate rhinophores originated several times within the family. Perfoliate rhinophores are present only in members of one of the most highly derived clades, that which includes Flabellina bicolor and its relatives (Table 1). The sister group of this clade includes F. affinis, and contains taxa with annulate rhinophores. The ancestors to these two clades had smooth rhinophores. It is clear that, within the Flabellinidae, both the annulate and perfoliate states are derived, but it is uncertain as to whether either condition is derived from the other. Functional arguments would suggest that perfoliate rhinophores would provide greater surface area than do annulate ones. From this perspective, it is hypothesized that perfoliate rhinophores are derived from annulate ones. 16. Penial papillae: Among members of the Flabellinidae, the presence of wartlike papillae on the penial papilla is limited to Flabellina telja. This state is not known in aeo- lidacean out-groups of flabellinids and represents a derived condition. ; 17. Denticles on lateral teeth: As discussed above, the taxa studied here include species with denticulate and smooth lateral teeth, and it has been concluded that den- ticulate teeth represent the ancestral condition. Two spe- cies of flabellinids with papillate rhinophores, Flabellina Page 130 /schitana 19 affinis funeka babai 15,18 engeli 6 bicolor 78 riwo bilas telja rubropurpurota albomarginata 3,15 baetica marcusorum 20 18 exoptata delicata 21 poenicia rubrolineata 8 bertschi pedora pellucida Figure 24 Cladogram depicting phylogeny of highly derived flabellinids included in this study. exoptata and F. delicata, have more numerous denticles than other members of their clade or than in out-groups of flabellinids. Therefore, lateral teeth with multiple den- ticles are considered derived from teeth with few denticles. 18. Notal brim: The presence of a distinct rim of tissue along the dorsolateral margins of the body has been con- sidered as a plesiomorphic feature within the Aeolidacea (ODHNER, 1939). In the least derived flabellinids, a con- tinuous notal brim is present. In more derived flabellinids, the notal brim is interrupted, and in the most derived taxa the brim is entirely absent. In the clade of flabellinids studied here, the notal brim is either partially or entirely reduced. The latter is considered derived within the in- group. 19. Prostate: In almost all flabellinids, the prostate is of uniform diameter throughout its length. In Flabellina af- The Veliger, Vol. 34, No. 2 finis, F. funeka, and F. ischitana, there is a constriction of the prostate near its distal end. This is considered a derived feature within this clade. 20. Anterior liver arch: In primitive members of the Flabellinidae and other aeolids, the cerata are arranged in simple linear rows. In a few derived flabellinids, the rows of cerata are elevated on a cushion that forms an arch- shaped expansion. This represents a derived state. As noted above, in Flabellina exoptata the postanal arches are sec- ondarily reduced to form single linear rows. 21. Receptaculum seminis: In most species of flabellinids, the receptaculum seminis is a semiserial structure con- sisting of a single spherical or pyriform sac (see character 7 above). In some species studied here, the receptaculum consists of two distinct lobes. A bilobed receptaculum is considered to represent the apomorphic state. In order to examine further the phylogeny of the taxa studied here, these morphological data were analyzed using PAUP (Phylogenetic Analysis Using Parsimony version 2.41 by David Swofford). All characters were treated as ordered, with the exceptions of the ornamentation of the rhinophores and the elaboration of the bursa copulatrix. The phylogeny of these highly derived Flabellinidae is presented here (Figure 24). GOSLINER & KUZIRIAN (1990) argued that the clado- gram they presented had implications for the systematics of the Flabellinidae. Exclusion of Flabellina and Cory- phellina from Coryphella as distinct genera rendered Cory- phella a paraphyletic taxon. Paraphyletic taxa are unten- able in modern phylogenetic classification. Therefore, all species were contained within the single genus Flabellina on the basis of priority. The present analysis demonstrates that maintenance of the traditionally accepted confines of Coryphella makes the genus polyphyletic as well as para- phyletic. The cladogram presented here is one of two most par- simonious cladograms. The other cladogram contains Fla- bellina riwo and F. bilas as sister taxa. These two taxa are the sister taxon of F. bicolor. The alternative hypothesis presented in Figure 24 was chosen since it required only one transformation of the depressed central cusp of the rachidian tooth to an elevated one. Instead, we hypothesize that the reduction of the bursa copulatrix occurred twice in these three taxa. The bursa copulatrix has been known to be reduced or lost in several other lineages. Several unresolved trichotomies are presented. Further examination of the highly derived flabellinids studied here and the inclusion of other undescribed taxa may facilitate the revision of the phylogenetic hypotheses presented. GOSLINER & KUZIRIAN (1990) noted that there is a distinct correlation between the phylogeny and biogeog- raphy of the Flabellinidae. Virtually all of the plesiomor- phic taxa are found in polar or cold temperate oceans. More derived taxa are generally found in temperate wa- T. M. Gosliner & R. C. Willan, 1991 Page 131 ey Lt tT | aes || ae Figure 25 Area cladogram of one clade of flabellinids with perfoliate rhinophores. ters, and the most derived taxa inhabit subtropical and tropical oceans. Area cladograms are presented for two of the clades studied here (Figures 25, 26). Neither of these examples demonstrates marked geographical separation or vicariance. Subsequent dispersal has swamped the original allopatric distributions at the time of speciation, and many of the species are presently sympatric over much of their ranges. In the one case where vicariance is clearly de- monstrable, the separation of Flabellina marcusorum pop- ulations on either side of the Isthmus of Panama, no dis- cernible morphological differentiation has occurred between allopatric populations (GOSLINER & KUZIRIAN, 1990), de- spite the fact that they have been separated for approxi- mately 1.6 million years (WOODRING, 1966; ROSEN, 1976). ACKNOWLEDGMENTS We are indebted to Robert Burn and Dr. W. D. L. Ride for assistance regarding specific names within the Flabel- linidae. Mr. R. Moolenbeek kindly answered our enquiries about the existence of the holotype of Flabellina macassar- ana. Field work in support of this study was made possible by two Smithsonian travel grants to Aldabra Atoll and the Seychelles, three fellowships, including diving and labo- ratory facilities from the Christensen Research Institute, Madang, Papua New Guinea, and the generosity and kindness of Kit Stewart who provided funds to collect material in Madagascar. The California Academy of Sci- ences also provided supplementary funds for all of the field work mentioned above. Many individuals kindly provided specimens and rec- ords assisting us in describing morphological variability and geographical distributions, including Robert Bolland, Gil and Jon Brodie, David Brunkhorst, Carol Buchanan, Clay Carlson, John Darr, Terry Frohm, Michael T. Ghi- selin, Michael Gosliner, Jeff Hamann, Patty Jo Hoff, Matthew and Serena Jebb, Scott Johnson, Ho Soon Lin, John Mizeu, Paulene Fiene-Severns, Eileen Sobeck, Chris Todd, Kathy Tubbenhauer, and Geoff Williamson. Page 132 The Veliger, Vol. 34, No. 2 } | n = J co o eee 3 bee oe cy 73 0 ry 170 1s 130 16 Ge 1 wet 130 us 170 103 2 Ey oo cy Figure 26 Area cladogram of flabellinids with triaulic reproductive system and papillate rhinophores. Lisa Borok printed the scanning electron micrographs, Pat Dal Porto prepared several tables, and Jean De- Mouthe prepared all the final pen and ink illustrations. We are especially grateful for their help. LITERATURE CITED BaBA, K. 1936. Opisthobranchia of the Ryukyu (Okinawa) Islands. Journal of the Department of Agriculture, Kyushu Imperial University 5(1):1-50. BaBA, K. 1955. Opisthobranchia of Sagami Bay. Supplement. Iwanami Shoten: Tokyo. 59 pp. BERGH, R. 1900. Die Opisthobranchen. Ergebnisse einer Reise nach dem Pacific (Schauinsland, 1896-1897). Zoologishe Jahrbucher, Abtheilung fiir Systematik Geographie und Biologie der Thiere 13:207-246. BERGH, R. 1905. Die Opisthobranchiata der Siboga Expedi- tion. Siboga Expeditie 50:1-248. BERTSCH, H. & A. J. 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Faune des Colonies Frangaises 2:1-460. RIsBEC, J. 1953. Mollusques nudibranches de la Nouvelle Ca- ledonie. Faune de l'Union Frangaise 15:1-189. Rosen, D. E. 1976. A vicariance model of Caribbean bioge- ography. Systematic Zoology 24:431-464. SCHMEKEL, L. 1970. Flabellina babai n. sp., ein neuer Aeolidier (Gastr. Nudibranchia) aus dem Mittelmeer. Pubblicacione della Stazione Zoologica di Napoli 38:316-327. VoicT, F. S. 1834. In: G. Cuvier. Das Thierreich 3:113-126. WAGELE, H. In press. A revision of the Antarctic genus No- taeolidia Eliot, 1905 (Gastropoda, Nudibranchia) with a description of a new species. Zoologica Scripta. WILLAN, R. C. & N. COLEMAN. 1984. Nudibranchs of Aus- tralasia. Australian Marine Photographic Index: Sydney. 56 PP- WooprInG, W. P. 1966. The Panama Land Bridge as a sea barrier. Proceedings of the American Philosophical 110(6): 425-433. The Veliger 34(2):134-165 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Nudibranch Spermatozoa: Comparative Ultrastructure and Systematic Importance by JOHN M. HEALY! anp RICHARD C. WILLAN Department of Zoology, University of Queensland, St. Lucia, Queensland, Australia 4072 Abstract. Spermatozoan ultrastructure is described for 27 nudibranch gastropods selected from both suborders (Anthobranchia, Cladobranchia) and all four superfamilies (Doridoidea, Dendronotoidea, Arminoidea, Aeolidoidea). Like most heterobranchs, nudibranchs possess complex spermatozoa char- acterized by distinctive acrosomal features (apical vesicle plus pedestal) and a highly modified mito- chondrial derivative (paracrystalline and matrix components enveloping an axoneme and glycogen-filled helical compartment). Although no sperm autapomorphy defining the Nudibranchia could be found, sperm morphology offers many useful indicators of relationships between and within superfamilies. Four groups within the Doridoidea can be distinguished based on acrosomal and nuclear features: (1) Dorididae (Jorunna, Rostanga, Doriopsis, Hypselodoris), Chromodorididae (Chromodoris); (2) Dorididae (Doris, Sclerodoris, Asteronotus), Hexabranchidae (Hexabranchus); (3) Polyceridae (Kaloplocamus), Gym- nodoridae (Gymnodoris); and (4) Phyllidiidae (Phyllidia, Phyllidiopsis). Wide variation in sperm mor- phology in examined Dendronotoidea (Lomanotidae [Lomanotus], Hancockiidae | Hancockia], Tritoniidae [Marianina]) suggests the possibility that this is not a natural assemblage. Among the heteroproct Aeolidoidea, two groups can be discerned: (1) Aeolididae (Aeolzdiella), Facelinidae (Pteraeolidia, Favo- rinus), Glaucidae (Glaucus, Glaucilla, Austraeolis); and (2) Flabellinidae (Flabellina, Coryphella). Rep- resentatives of the Acleioprocta await examination. At present, available sperm data for the Nudibranchia (or in fact most opisthobranch taxa) are insufficient to reach definitive conclusions concerning relation- ships with other opisthobranchs. A close relationship between the Anthobranchia and pleurobranchid notaspideans seems evident, though on the basis of comparative anatomy it seems likely that both groups have retained sperm features from a common ancestral stock. INTRODUCTION Nudibranchs comprise one of the most well known and visually conspicuous groups of marine gastropods (THOMPSON, 1976). Their striking color patterns and di- verse morphology have made them favored subjects for aquatic photography, but in terms of taxonomic impor- tance, these same factors have led to the creation of nu- merous very small or monotypic families or genera now recognized as superfluous (WILLAN, 1988). The order Nu- dibranchia contains perhaps as many as 1000 species (Boss, 1982) and is usually divided into four superfamilies— Doridoidea, Aeolidoidea, Arminoidea and Dendronotoi- dea—distributed between the suborders Anthobranchia (Doridoidea) and Cladobranchia (containing the three oth- er superfamilies) (WILLAN & COLEMAN, 1984). A number ' Present address: Queensland Museum, South Brisbane 4101, P.O. Box 300, Queensland, Australia of important systematic and phylogenetic problems remain to be settled in the study of the Nudibranchia such as the origin of the group and the relationships between constit- uent superfamilies and families. Recent studies have established beyond question that spermatozoan fine structure is an extremely useful indi- cator of taxonomic affinity within the Mollusca (POPHAM, 1979; HODGSON et al., 1988; HEALY, 1989a, b), particu- larly in the class Gastropoda (GrusTI, 1971; GrusTI & SELMI, 1982; KOHNERT & STORCH, 1984; KOIKE, 1985; HEALY, 1982-1988; HEALY & WILLAN, 1984; HODGSON & BERNARD, 1988). Among the Gastropoda, the subclass Prosobranchia has been studied extensively with regard to comparative sperm morphology and sperm development, partly because of the occurrence of sperm dimorphism in many taxa (for a full list of references see GIUSTI & SELMI, 1982; KOHNERT & STORCH, 1984; KOIKE, 1985; HEALY, 1988a). By comparison, few ultrastructural studies of opis- thobranch spermatozoa have been carried out (Pyrami- J. M. Healy & R. C. Willan, 1991 delloidea HEALY, 1988b; the cephalaspidean Jornatina sp., HEALY, 1982a; Notaspidea, HEALY & WILLAN, 1984; An- aspidea, THOMPSON & BEBBINGTON, 1969, 1970; TTHOMp- SON, 1973; KuBo & ISHIKAWA, 1981). In a pioneering paper, THOMPSON (1973) presented a broad outline of sperm ultrastructure within the Opisthobranchia (includ- ing some nudibranchs) and Pulmonata, though with pri- mary emphasis on the helical form of the midpiece and nucleus, rather than morphology of the acrosomal complex. Earlier, THOMPSON (1966) provided the first reconstruc- tion of a nudibranch spermatozoon using transmission elec- tron microscopy (TEM) (allosperm of Archidoris pseu- doargus Rapp). Recent studies of nudibranch spermiogenesis include those on Spurilla neapolitana (Delle Chiaje) (Ey- STER & ECKELBARGER, 1979; ECKELBARGER & EYSTER, 1981; ECKELBARGER, 1982) and Hypselodoris tricolor (Can- traine) (MEDINA et al., 1985, 1986, 1988a). SCKMEKEL (1971), HOLMAN (1972), and MEDINA et al. (1988b) also include ultrastructural observations on mature spermato- zoa of nudibranchs: SCHMEKEL (1971) was in fact the first worker to demonstrate full details of the acrosome in any nudibranch (for Doris verrucosa Linné). In addition to these electron microscopical studies, ROGINSKAYA (1964, light microscopy) has reported dimorphic sperm nuclei in seven species of Coryphella, but only a single type of nucleus in spermatozoa of 22 other nudibranchs (representing the Doridoidea, Dendronotoidea, and Aeolidoidea). The aims of the present study are firstly to document sperm morphology throughout the Nudibranchia, and sec- ondly to determine whether or not sperm characters can be used to resolve taxonomic and/or phylogenetic problems within the group. In order to achieve these goals we have examined as wide a range of taxa as possible (38 species [27 at TEM level] from both suborders and all four su- perfamilies) and where available, incorporated TEM data from previously studied species. We dedicate this paper to the memory of T. E. Thomp- son, a tireless worker devoted to the study of the Opistho- branchia (especially Nudibranchia) and a firm believer in the relevance of “new” fields of research such as sperm ultrastructure to the study of molluscan taxonomy and phylogeny. MATERIALS anpD METHODS A total of 38 species were collected for this study from localities in Queensland (QLD), New South Wales (NSW), and Papua New Guinea (PNG) (Table 1). Of these species 27 were processed for TEM while the remaining 11 con- tained only sufficient spermatozoa to determine nuclear and whole sperm length using light microscopy. Voucher specimens of all species examined have been deposited at the Australian Museum (Sydney). In most of the species processed for TEM, tissues from freshly gathered animals were fixed in 3% glutaraldehyde (prepared in 0.2 M phosphate buffer) at 0-4°C. Post- glutaraldehyde processing of PNG material could not be Page 135 carried out until return to Brisbane, resulting in a primary fixation period of three weeks. Although this delay did adversely affect the quality of fixation in some instances, spermatozoa were always adequately preserved for TEM. Small (1-2 mm’) portions of the hermaphrodite duct, ampulla, and/or ovotestis were processed depending on the reproductive state of available animals (Table 1). After glutaraldehyde fixation, tissues were rinsed thoroughly in cold 0.2 M phosphate buffer, then placed in a 1% osmium tetroxide solution (prepared in 0.2 M phosphate buffer) for 80 min at 0-4°C. Following osmication, the tissues were rinsed in cold buffer, dehydrated in a graded ethanol series, and embedded in Spurr’s epoxy resin. Tissues from Sclerodoris cf. apiculata, Dendrodoris nigra, Glaucilla marginata, and Glaucus atlanticus were obtained from specimens fixed in seawater-formalin. After thorough rinsing in seawater, tissue samples of these four species followed the processing schedule outlined above. Ultrathin sections were cut using an LKB IV Ultratome and collected on 200 mesh uncoated copper grids. Speci- men-bearing grids were then stained with uranyl acetate and lead citrate according to the method of DADDOw (1983) and examined with an Hitachi 300 TEM operated at 75 kV. Whole spermatozoa were observed using an Olympus microscope adjusted for phase-contrast microscopy. RESULTS In view of the large number of nudibranch species ex- amined during the course of this study, and in order to avoid much repetitious description, we have adopted a collative approach in the presentation of our results. The work is subdivided on the basis of the superfamily to which each taxon belongs—each section consisting of a detailed description for « representative species (e.g., Chromodoris annae for Doridoidea), followed by notes summarizing sperm morphology in other members of the superfamily. As far as possible, descriptions for each taxon are supported by micrographs or line drawings. Where spermatozoa were absent or present only in low numbers within the her- maphrodite duct or ampulla our observations were limited to ovotesticular sperm (see Table 1). Aside from occasional variation in nuclear substructure and granule content of the glycogen helix, we found no morphological differences between sperm from the hermaphrodite duct, the ampulla, or the ovotestis in any given species. Table 2 provides a summary of measurements for sperm components in each species examined at the ultrastructural level. DORIDOIDEA CHROMODORIDIDAE—Chromodoris annae (Bergh) Acrosomal Complex The acrosomal vesicle is spheroidal (0.13 wm long, 0.12 um wide), membrane-bound, and rests in a shallow an- terior depression of the acrosomal pedestal (Figure 1A, B). The pedestal is conical, 0.8-0.85 wm long (including Page 136 The Veliger, Vol. 34, No. 2 Table 1 Species examined in this study using TEM. Sperm Fixation, tissue length Species Locality (for TEM) (um) DORIDOIDEA HEXABRANCHIDAE Hexabranchus sanguineus (Ruppell & Leuckart, 1828) Shag Rock, QLD Glut., hd/amp. 390 POLYCERIDAE Tambyja cf. oliva Meyer, 1977 Madang lagoon, PNG Glut., hd/amp. 135-150 Kaloplocamus yatesi (Angas, 1864) Coffs Harbour, NSW Glut., hd/amp. 270-280 GYMNODORIDIDAE Gymnodoris sp. Madang lagoon, PNG Glut, ovot. 425-440 CHROMODORIDIDAE Chromodoris annae Bergh, 1877 Madang lagoon, PNG Glut., hd/amp. 270-280 C. magnifica (Quoy & Gaimard, 1832) Madang lagoon, PNG Glut., hd/amp. 270 C. lochi Rudman, 1982 Astralabe Bay, PNG Glut., hd/amp. n.d. Glossodoris atromarginata (Cuvier, 1804) Shag Rock, QLD Glut., ovot. n.d. Miamira magnifica Eliot, 1910 Coffs Harbour, NSW — 100-125 Ceratosoma tenue Abraham, 1876 Coffs Harbour, NSW — 200-215 Hypselodoris cf. nigrostriata (Eliot, 1904) Coffs Harbour, NSW — 465-475 DORIDIDAE Rostanga arbutus (Angas, 1864) Hastings Point, NSW Glut, ovot. 245-250 Jorunna pantherina (Angas, 1864) Hastings Point, NSW Glut., hd/amp. 190 Doriopsis granulosa Pease, 1860 Coffs Harbour, NSW Glut., hd/amp. 215 Sclerodoris cf. apiculata (Alder & Hancock, 1864) Maclean, NSW SWF, ovot. 240-245 Asteronotus cespitosus (Hasselt, 1824) north of Madang, PNG Glut., hd/amp. 310-315 Halgerda tessellata (Bergh, 1880) Madang lagoon, PNG — 340-350 Discodoris concinna (Alder & Hancock, 1864) Coffs Harbour, NSW — 470-475 DENDRODORIDAE Dendrodoris nigra (Stimpson, 1855) south of Port Macquarie, NSW SWF, hd/amp. 380-400 NSW Doriopsilla miniata (Alder & Hancock, 1864) Hastings Point, NSW — 587-612 PHYLLIDIIDAE Phyllidia ocellata Cuvier, 1804 Coffs Harbour, NSW — 312-340 Phylhidia nobilis Bergh, 1869 Shag Rock, QLD Glut., hd/amp. 310-340 Phyllidiopsis cardinalis Bergh, 1876 Astrolabe Bay, PNG Glut., hd/amp. 165-175 Phyllidiopsis striata Bergh, 1888 Madang lagoon, PNG — 215-240 AEOLIDOIDEA FACELINIDAE Pteraeolidia ianthina (Angas, 1864) Tangalooma Channel, QLD Glut., hd/amp. 390-395 Favorinus japonicus Baba, 1949 Hastings Point, NSW Glut., ovot. n.d. GLAUCIDAE Glaucus atlanticus Forster, 1777 Fingal Beach, NSW SWF, hd/amp. 160-170 Glaucilla marginata Bergh, 1860 Fingal Beach, NSW SWF, hd/amp. n.d. Austraeolis ornata (Angas, 1864) Hastings Point, NSW — 340-345 AEOLIDIIDAE Aeolidiella indica Bergh, 1888 Coffs Harbour, NSW Glut, hd/amp. 200-225 Aeolidiella alba Risbec, 1928 Hastings Point, NSW —_ 187-200 FLABELLINIDAE Flabellina rubrolineata (O’Donoghue, 1929) Coffs Harbour, NSW Glut., hd/amp. 260-270 DENDRONOTOIDEA LOMANOTIDAE Lomanotus vermiformis Eliot, 1908 Stradbroke Is., QLD Glut., hd/amp. 200-230 J. M. Healy & R. C. Willan, 1991 Page 137 Table 1 Continued Sperm Fixation, tissue length Species Locality (for TEM) (um) HANCOCKIIDAE Hancockia sp. Madang lagoon, PNG Glut., ovot. n.d. TRITONIIDAE Marianina rosea (Provot-Fol, 1930) north of Madang, PNG Glut., ovot. n.d. Marionia cyanobranchiata (Ruppell & Leuckart, 1831) Coffs Harbour, NSW - 320-330 ARMINOIDEA ARMINIDAE Dermatobranchus fortunata Bergh, 1874 Madang lagoon, PNG Glut, ovot. n.d. DORIDOMORPHIDAE Doridomorpha gardineri Eliot, 1906 Madang lagoon, PNG Glut., hd/amp. n.d. Abbreviations: NSW, New South Wales; PNG, Papua New Guinea; QLD, Queensland; Glut., glutaraldehyde; SWF, seawater formalin; hd/amp., hermaphrodite duct and/or ampulla; ovot., ovotestis; n.d., not determined. a short [0.23 um] overlap zone with the nuclear apex), and lacks any enveloping membrane (Figure 1A-D). Longi- tudinal sections through the pedestal often reveal fine par- allel striations, arranged at approximately 20° relative to the transverse plane and repeating at a distance of 12.5 nm (Figure 1D). Nucleus The nucleus is 7—7.5 yum long, helically coiled, and cir- cular in transverse section (Figure 1E, F). Contents of the nucleus are finely granular and evenly electron dense. Ba- sally, a shallow (0.4-0.45 wm deep) invagination is filled by a bell-shaped centriolar derivative continuous with the axoneme/coarse-fiber complex (Figure 1E, F). Both with- in and beyond the nuclear invagination the microtubular nature of the axonemal doublets and singlets is obscured by dense material (Figure 1E, G). The doublets always remain distinct from the coarse fibers, though usually in contact with them (Figure 1E). Slight overlap occurs be- tween the base of the nucleus and the thin, anterior ex- tremity of the mitochondrial derivative (Figure 1E, F). A subnuclear ring occurs in this region of the spermatozoon (Figure 1F). Midpiece The midpiece in Chromodoris annae is composed of the axoneme/coarse-fiber complex ensheathed by the mito- chondrial derivative (Figure 1F-L) and measures ap- proximately 260 um. Immediately posterior to the nucleus, the coarse fibers that surround the 9+2 axoneme are thick (0.1-0.12 um wide) and prominently banded (periodicity 45 nm) and are surrounded by dense glycogen deposits and a thin anterior extension of the mitochondrial deriv- ative (Figure 1E, F). As these fibers progress further into the midpiece, they rapidly decrease in diameter, and their periodic substructure becomes less evident (Figure 1F, G). The mitochondrial derivative consists of paracrystalline and matrix materials which enclose: (1) the glycogen (or primary) helix—a helical compartment containing gly- cogen granules—and (2) the axoneme/coarse-fiber com- plex (Figure 1F-L). Oblique longitudinal and transverse sections through the midpiece best show the helical, lattice- like substructure of the paracrystalline material (Figure 1H, I). The matrix component of the mitochondrial de- rivative is subdivided into helical tracts, two of which are expanded to form secondary helices in the immediate post- nuclear region of the midpiece (Figure 1F, H-J). Pro- gressing posteriorly, first one (Figure 1G) then both (Fig- ure 1K) of these secondary helices are lost. Similarly, the glycogen helix diminishes in size along the length of the midpiece and is absent from the posterior region (Figure 1L). The terminal region of the midpiece consists of the axoneme enclosed by the cylindrical extension of the mi- tochondrial derivative (Figure 1L). Glycogen Piece A glycogen piece, in the strict sense, is absent in Chro- modoris annae. Instead, a cap-shaped body (length 0.13 um), probably a modified annulus, seals off the degener- ating axoneme to form the distal end of the spermatozoon (Figure 1L). Other CHROMODORIDIDAE [TEM: Chromodoris mag- nifica (Quoy & Gaimard), Chromodoris lochi Rudman, Glossodoris atromarginata (Cuvier)—(not illustrated); N fe) snaponu/M ZA, quasaid¢ quasqei = SJ90 (7 29 YS ‘pu ‘pu ]294/M (wi ¢) Joys = pauTMjua ‘(4 )8u0T (wi /0°0) [Tews snaiuodol snursoany aS sngjo ine) -nu/M pauIM} a. quasoid¢ quasqeé S]99% oS ‘ys wu GG [epruod ‘prjos sjeoy/M (Wn pp) WOYS = -Ua ‘(WIT ¢Z) uo] (wi 60'0) [Tews DUIYJUDI DIPIOaDLa}q o = AVGINITIOV] ae VAdIOCITIOdUV Sp quosoid¢ quasaid¢ Ajuo ‘y'3/M wu $G podeus |jaq (wir cj) Bu0] ~=(w Q'[-6'9) Su] ~=— (wi g{ 9) Bu0TqGo sypurpsv9 sisqdoipyjAyd a quasaid¢ quasaid¢ Ajuo "y'3/M wu G podeyus |]9q (wi g{[-z]) Suoy (wm Q{[-670) Suc, § = (win gy (9) Buojgo syiqou vipyjAyg > AVAGIIGITTAHG gS yuasaid¢ quasqe¢ Ajuo -y'3/M ‘pu podeys |jaq (ui 7) \10ys (wi g°Q) Buoy (wm ¢{'Q) uMIpaur DLGIU S1LOpOLpUaCy on avdalaodoucqnaqd (win €'0-2'0) Woys quasoid; juasqe¢ Ayuo "y3/M ‘pu pedeys [aq (win p) 10Ys (ui (win 7'(Q) adie] snsoqidsaa snjouosajsp quasoid; juasqeé Ajuo "y3/M WU $G pedeys {[2q (win p) ous €'0-Z'0) ous (wi 79) adie] pyojnr1qv “jo si4opo.1ajas pedeys 3urs quasoid AJuo ‘y'3/M wu ZG podeys [aq (wi p{) Buoy (win 9¢‘Q) Suoy (ur c{°9) wntpeu psojnuvis sisqo1s0og spueq jUDIN] UOIITa podeyus Burs quasaid AJuo ‘y'3/M wu Gp pedeus |]9q (win g) y10ys ‘(wi 9°Q) Buoy] (wm ¢]‘Q) wWnIpou Duilayjuvg vuunsof spueq uy pedeys 3urs quosoid ATuo "y'3/M wu Gp padeys |[2q (un 4) 10ys ‘(win 9°Q) Buoy (wm p]'—9) UNIpoUT sSnyngiv DsUdISOY aAvVdIdI4odg spueq ouy podeys deo quasqe = SJa04} og W YS wu cp podeys [aq (win ¢*/) Joys ‘(wi g'Q) Buoy (wa ¢] 9) WnIpow IDUUD SILOPOUWOLY’) AVGIGIYOGOWOUH:) spueq asso quasaid¢ juasqe¢ Ajuo ‘y8/M wu /¢ padeys ]jaq (uu ) 10ys ‘(wi [°z) Buoy (wm cG]‘Q) UMIpow ‘ds stuopouwty AVGIGCIYOGONWA‘L) spueq asre0o podeys 3urs quasoid Ajuo ‘y'8/M WU pp podeys [aq (wi ) 110ys ‘(wi 41) Buoy (wm ¢] 9) UNIpow asaqok snuv20)qojvy podeys deo juasqe Ajuo -y'3/M ‘pu podeys |jaq (wi y) .10ys (ui ¢°Q) 10s (wi g]°Q) 281] payo "jo vlqun AVGIYAOATOD quasoid ¢ yuasqe¢ Ayuo "y3/M ‘pu podeys [Jaq (win yp) Joys (win /['Q) WoYS (win ¢Z'Q) aB1e] snauinsuvs snyIUuDLQDxaT] AVGIHONVAEVXAH VACIOdIYOd snjnuuy aoa1d soardpiyy Ay1o1p JATIVALIOP snaponn ]eIsapog IpIsaA, satadg uaZ0o4[5 -oriad Jeponuay : : xa[duroo ;ewoso1y Toqhy Page 138 ‘patpnys sareds ut sunjonssenjn weds aanesreduior c AGL Page 139 J. M. Healy & R. C. Willan, 1991 peuruiajap 10u “p'u {x1jay uasodATS “YS :suoneIAsiqqy podeus suts quasoid 1299 © 7 US wu Zs padeus [aq (é)oys = (wi p'Q) UNTpouT (wi go'9) [Tews laUulplos DYGLowopi40q aAVGIHdYOWNOCIAOGd quasaid¢ quasqeé Ajuo ‘y'3/M ‘pu ‘pu s[eo4/M (¢)10Ys (é) Joys ‘pu DIDUNILOL SNYIUDLGOJDULLACT AVGIHONVAFOLVNAACG VACIONINAV quasaid; yuasqeé Ajuo ‘y'3/M wu ZG podeus |j9q sja0y/M (¢)110Ys (wi [°Q) Woys (wim 60'0) [Tews DaSOL DUIUDILDIAT (AVNININVIUVJA]) AVGINOLM J, (wi quasoid¢ quasqe¢ Ajuo “‘y'3/M wu $G podeys |[9q (é)j40ys GZ'0-Z'0) ous (ui 7Z'Q) a81e] ‘ds miy0ounpy AVCIMOOONVH (un podeys Burs: juasaid ATuo “y3/M wu gp pedeus |j2q (ui yp) 10ys GZ'0-Z'0) Noys (wi 9¢'Q) Buo[go SIULLOPIWLGA SNJOUDWLOT AVGILONVWO'T VACIOLONOYANAG 2a0018 “JONU UT podeus Burs quasaid ATuo -y3/M wu QP [eoTUOD ‘prfos ]J204/M (ui /) yoys = (wi —E'Z-g"]) BUOT (wi 60'0) [Tews DIDIUIOLGNL DUIJAQD] AVCINITTAIV TY snapnu/M quasoid: quasqe’ S]999 of UB ‘pus [eoruod ‘pros sja0y/M (wi ¢) 1Z0YsS poutmquoa ‘(¢)3u0] ‘pu DIIpUl DIJaIpyoay aAVdIIdCI Tory sna]o -nu/M pouIM} quasaid¢ quasqec saa og UB ‘pu —s- [BoTUOD ‘pryTos sjeey/M (un ¢) JZ0YsS -ua ‘(win Z) BuO] (wi 900) [[Teuls DIDUIGLDUL DIJIINDILH aVdIONVTL) sn[nuuy aoaid soard pry AVIO1p dAeALIOP snaponN [e1sopog JOISI A, satoads uaB004[5 -oliod Iepornuay — sation 9 JOqty penunuor GAGIAL, The Veliger, Vol. 34, No. 2 Page 140 1, thes uf Ay 20; Mad 5 lia ete Be iss Nea x Figure 1A-L: Chromodoris annae. Figure 1A, B. Longitudinal sections (LS) through acrosomal complex and nuclear apex (1A x 57,600; 1B x 63,000). Figure 1C. Transverse section (TS) acrosomal pedestal (x 72,000). J. M. Healy & R. C. Willan, 1991 Light microscopy: Miamira magnifica Eliot; Ceratosoma tenue Abraham; Hypselodoris cf. nigrostriata (Eliot) | Spermatozoal features of other Chromodoris species are essentially as outlined above for C. annae. Glossodorts atro- marginata differs from Chromodoris spp. in having a prom- inent helical keel present in the nucleus. Although no data on the acrosome in Glossodoris atromarginata could be ob- tained, the distal region of the spermatozoon appears to be cap-shaped and composed of nine segments. Sperm length is extremely variable in the Chromodorididae. The shortest was observed in Miamira magnifica (100-125 wm) and the longest, those of Hypselodoris cf. nigrostriata (465- 475 um) (see Table 1). DoRIDIDAE [TEM: Rostanga arbutus (Angas) (Figure 2A-G), Jorunna pantherina (Angas) (Figure 2H-M), Donopsis granulosa Pease (Figure 3E-I), Sclerodoris cf. apiculata (Alder & Hancock) (Figure 3A—D), Aster- onotus cespitosus (Hasselt) (see Figure 11); Light mi- croscopy: Halgerda tessellata (Bergh), Discodoris concin- na (Alder & Hancock), Hypselodoris cf. nigrostriata (El- iot, 1904)| The Dorididae show marked variation in the morphol- ogy of the nucleus and acrosomal complex. Rostanga ar- butus (Figure 2A-G), Jorunna pantherina (Figure 2H-M) and Doriopsis granulosa (Figure 3E-I) show similar ac- rosomal and midpiece features to those described for Chro- modoris annae; Rostanga arbutus in fact also exhibits fine striations within the pedestal (Figure 2B). Nuclei of Do- riopsis granulosa (12-14 wm) are appreciably longer than those of other dorids (4-8 um), but helically shaped like Jorunna pantherina (Figure 21), Chromodoris spp., and Sclerodoris cf. apiculata (Figure 3A). Unlike Chromodoris annae, a glycogen piece is present in spermatozoa of Rostan- Page 141 ga arbutus (length 0.4 um, Figure 2E, G), Jorunna panther- ina (length 1.25 um, Figure 2M) and Doriopsis granulosa (length 0.58 wm, Figure 31). The axoneme persists to the terminal edge of the glycogen piece in Doriopsis granulosa (Figure 31). Axonemal microtubules are absent from the glycogen piece and the distal portion of the midpiece of Jorunna pantherina (Figure 2M). Similarly, the glycogen piece of Rostanga arbutus also contains only dense granules (Figure 2E, G), though some transverse sections reveal that the axoneme is present in the distal region of the midpiece. A subnuclear ring is observed in all studied members of the Dorididae (e.g., Figures 2J, 3C, F). Sperm length is variable in the Dorididae, ranging from 190 um in forunna pantherina to 475 wm in Discodoris concinna (see Table 1). Spermatozoa of Sclerodoris cf. apiculata (Figure 3A-D) and Asteronotus cespitosus (see Figure 11) differ from other investigated dorids and the Chromodorididae principally in having a larger acrosomal vesicle (length 0.18 wm, breadth 0.2—-0.24 um) positioned on a short (0.2-0.3 um) pedestal (Figure 3B). The fibrous, inflated appearance of the nu- cleus in Asteronotus cespitosus is possibly due to osmotic stress, though in other nudibranch species where this phe- nomenon was observed (e.g., Hexabranchus sanguineus [Figure 3J, K], Kaloplocamus yatesi [Figure 4E], Lomanotus vermiformis [Figure 9C]) other sperm organelles show little sign of osmotic stress. The shallow basal invagination of the nucleus in Sclerodorvs cf. apiculata is occupied by a bell- shaped centriolar derivative and the distal accessory sheath (Figure 3C). Coarse fibers of Sclerodoris have a banding periodicity of 54 nm. Morphology of the midpiece in Sclero- doris cf. apiculata and Asteronotus cespitosus appears similar to other dorids (Figure 3C, D), though in Sclerodoris cf. apiculata, the matrix component of the mitochondrial de- rivative is lamellate anteriorly (Figure 3C). Unfortunately Figure 1D. Striated substructure of pedestal. Pedestal lying horizontally (long arrows indicating direction of striations) (x 84,000). Figure 1E. TS junction of nucleus and midpiece. Note coarse fibers (surrounding 9+2 axoneme), and glycogen from neck region of midpiece. Arrow indicates anterior extremity of mitochondrial derivative (xX 44,600). Figure 1F. LS nucleus-midpiece junction. Arrows indicate subnuclear ring (x 30,000). Figure 1G. TS proximal region of midpiece showing glycogen helix and secondary helix (x 42,000). Figure 1H. LS detail of midpiece showing paracrystalline and matrix materials (x 75,600). Figure 1I. Oblique TS of midpiece. Matrix and paracrystalline components of mitochondrial derivative visible (x 44,500). Figure 1J. LS proximal region of midpiece with two secondary helices (x 30,000). Figure 1K. LS middle region of midpiece. Note absence of secondary helices ( x 30,000). Figure 1L. LS through terminal region of spermatozoon. Cap-shaped structure (arrow) probably represents a form of annulus (x 50,000). Abbreviations: ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; gh, glycogen helix; ma, matrix material; n, nucleus; p, paracrystalline material; sh1, sh2, secondary helices. The Veliger, Vol. 34, No. 2 Page 142 J. M. Healy & R. C. Willan, 1991 the terminal region of the spermatozoon was not observed for Sclerodorts cf. apiculata or Asteronotus cespitosus, despite many hours of TEM observation. Possibly the glycogen piece is reduced to a vestigial cap as noted above for the chromodorids (see Figure 1L). HEXABRANCHIDAE [TEM: Hexabranchus sanguineus (Ruppell & Leuckart) (Figure 3J, K)] Sperm features of Hexabranchus sanguineus, in partic- ular the structure of the acrosomal complex (Figure 3J, K), are very similar to those observed in the dorids Sclero- doris cf. apiculata and Asteronotus cespitosus. Sperm nuclei of Hexabranchus sanguineus (Figure 3K) are round and coarsely fibrous as observed in Asteronotus cespitosus. A bell-shaped centriolar derivative fills the shallow basal in- vagination of the nucleus (Figure 3K). The immediate post-nuclear region of the midpiece shows lamellar orga- nization of the matrix component of the mitochondrial derivative. No data on the presence or morphology of the glycogen piece could be obtained. Mature spermatozoa measure approximately 390 um. POLYCERIDAE [TEM: Tambyja cf. oliva Meyer, Kalo- plocamus yates: (Angas) The two investigated polycerids differ markedly from each other in acrosomal and glycogen piece morphology. Page 143 In Tambya cf. oliva (not illustrated), the acrosomal com- plex is similar to those of Sclerodoris cf. apiculata, Aster- onotus cespitosus, and Hexabranchus sanguineus. The nu- cleus is short (4 um), fibrous, and rounded in appearance with a shallow basal invagination (0.3 wm deep) occupied by a bell-shaped centriolar derivative. Midpiece mor- phology resembles that observed in most other dorids (one glycogen helix, no secondary helices), and the glycogen piece is reduced to a dense cap-shaped structure similar to Chromodoris annae (see Figure 1L). A subnuclear ring is present. Spermatozoa of Kaloplocamus yatesi also possess a short (3-4 um), fibrous nucleus with a shallow (0.33 um deep) basal invagination to accommodate the centriolar deriva- tive and anterior portion of the distal accessory sheath (Figure 4E). The coarse fibers, which do not enter the nuclear invagination, have a maximum thickness of 0.08 um and exhibit primary periodic banding of 44 nm. The acrosomal pedestal (length 1.44 um) is significantly longer than those of other doridoids (range 0.2-0.85 um), and shows coarse transverse banding (composed of alternating dense and electron-lucent bands; distance between centers of dense bands, 75 nm) (Figure 4C). However, the shape of the pedestal (conical, angularly overlapping the nuclear apex, Figure 4C), size of the acrosomal vesicle (length 0.13 um, breadth 0.12 wm, Figure 4C) and morphology of the midpiece (Figure 4C-F) are essentially as observed in Figure 2A-L: Figure A-F, Rostanga arbutus; Figure G-L, Jorunna pantherina Figure 2A. LS acrosomal complex and nuclear apex (56,000). Figure 2B. Striated substructure of pedestal (striation direction indicated by long arrows). Pedestal lying horizontally (x 58,000). Figure 2C. LS acrosomal complex, nucleus (showing helical keel) and proximal portion of midpiece (x 18,500). Figure 2D. LS junction of nucleus and neck region of midpiece ( x 35,000). Figure 2E. Annulus at junction of midpiece and glycogen piece (x 32,000). Figure 2F. LS midpiece (x 32,000). Figure 2G. TS glycogen piece. The lumen contains no axoneme (x 38,000). Figure 2H. LS acrosomal complex showing angled striations in the pedestal (x 56,000). Figure 21. LS nucleus showing helical coiling (x 9,300). Figure 2J. LS junction of nucleus and proximal region of midpiece. Arrows indicate subnuclear ring (x 47,000). Figure 2K. LS midpiece (x 42,000). Figure 2L. TS midpiece (x 47,000). Figure 2M. LS junction of midpiece and glycogen piece (x 38,000). Inset: TS terminal region of glycogen piece (Xx 50,000). Abbreviations: a, acrosomal complex; an, annulus; ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; das, distal accessory sheath; gh, glycogen helix; gp, glycogen piece; k, nuclear keel; M, midpiece; ma, matrix material; n, nucleus; p, paracrystalline material. The Veliger, Vol. 34, No. 2 Page 144 J. M. Healy & R. C. Willan, 1991 chromodorids and other dorids. A subnuclear ring is pres- ent (Figure 4E). The axoneme persists within the distal region of the midpiece but degenerates into a rod-shaped structure within the lumen of the glycogen piece (Figure 4G). The glycogen piece measures 0.6 wm in length and is preceded by an annulus attached to the plasma mem- brane (Figure 4F, G). Mature spermatozoa of Tambya cf. oliva measure 135-150 um, while those of Kaloplocamus yatest measure 270-280 um. GYMNODORIDIDAE [TEM: Gymnodoris sp.] Results obtained for Gymnodoris sp. closely match those described above for Kaloplocamus yates: with the exception that the coarsely banded pedestal is longer in Gymnodoris sp. (2.1 um), shows evidence of longitudinally aligned fi- bers, and features a prominent, unbanded lateral region (Figure 4B). The acrosomal vesicle measures 0.15 wm in length and 0.116 wm in breadth (Figure 4B). Figure 4C indicates the presence of an unbanded region of the pedestal in Kaloplocamus yates: though in comparison with Gym- nodoris sp. this feature is poorly developed. Nuclei of tes- ticular spermatozoa are short (3-3.5 um long) and uni- formly electron dense (in contrast to the inflated, fibrous nuclei of Kaloplocamus yates:) and lacking any keel(s). The morphology of the glycogen piece and distal region of the midpiece was not determined. Features of the midpiece of Gymnodoris sp. are as previously noted for Kaloplocamus yatest, Chromodorididae, and Dorididae. Spermatozoa of Gymnodoris sp. are 425-440 um long. Page 145 DENDRODORIDAE [TEM: Dendrodoris nigra (Stimpson) (not illustrated); Light microscopy: Doriopsilla miniata (Alder & Hancock)] Our limited TEM observations on mature spermatozoa of Dendrodoris nigra indicate similar sperm morphology to chromodorids and certain doridids, notably Doriopsis gran- ulosa. The glycogen piece was not observed. Spermatozoa of Doriopsilla miniata are notable in being the longest re- corded for the Nudibranchia (587-612 um), while those of Dendrodoris nigra measure 380-400 um. PHYLLIDIIDAE: [TEM: Phyllidia nobilis Bergh, Phyllidi- opsis cardinalis Bergh; Light microscopy: Phyllidia ocel- lata Cuvier, Phyllidiopsis striata Bergh] In phyllidiid species examined with TEM, the acro- somal pedestal is slender, 0.9-1.0 um long, and apically supports an oblong acrosomal vesicle (length 0.18 um, breadth 0.08 wm) (Figure 5A, E). Often the pedestal is curved, occasionally to an exaggerated degree (Figure 5C) demonstrating the flexibility of this sperm component. As in many other doridoids, the bases of the acrosomal ped- estal and nuclear apex are angularly overlapped in lon- gitudinal sections (Figure 5A, C, E). Nuclei are long (12- 15 wm in Phyllidia spp., 15-25 wm in Phyllidiopsis spp.), finely tapered anteriorly, and circular in transverse section. Although nuclei of Phyllidiopsis spp. show evidence of slight helical coiling (Figure 5B) nuclear keels appear to be absent in the Phyllidiidae. Basally, the nucleus exhibits a shallow invagination occupied largely by a bell-shaped Figure 3A-K: Figure A—D, Sclerodoris cf. apiculata; Figure E-I, Doriopsis granulosa: Figure J, K, Hexabranchus sanguineus Figure 3A. LS acrosomal complex, nucleus, and proximal portion of midpiece (Xx 14,400). Figure 3B. LS detail of acrosomal complex and nuclear apex (x 60,000). Figure 3C. LS junction of nucleus and midpiece. Arrows indicate subnuclear ring (x 45,000). Figure 3D. LS midpiece (x 22,500). Figure 3E. LS acrosomal complex and nuclear apex (x 60,000). Figure 3F. LS junction of nucleus and midpiece. Subnuclear ring indicated by arrows (x 43,500). Figure 3G. Oblique TS midpiece showing paracrystalline layers (x 67,500). Figure 3H. TS showing reduction in size of midpiece from anterior (upper) to posterior (lower) regions (X 42,000). Figure 31. LS junction of midpiece and glycogen piece showing annulus (x 45,000). Figure 3J. LS acrosomal complex and nuclear apex (x 60,000). Figure 3K. LS acrosomal complex, nucleus (fibrous, inflated), and proximal portion of midpiece (x 18,750). Abbreviations: a, acrosomal complex; an, annulus; ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; das, distal accessory sheath; gh, glycogen helix; gp, glycogen piece; M, midpiece; ma, matrix material; n, nucleus; p, paracrystalline material. The Veliger, Vol. 34, No. 2 Page 146 J. M. Healy & R. C. Willan, 1991 centriolar derivative continuous with the axoneme/coarse- fiber complex and penetrated by the central pair of axo- nemal microtubules (Figure 5F). Also present is a diffuse distal accessory sheath (partly extending into the nuclear invagination) and a subnuclear ring (Figure 5F). Imme- diately posterior to the nucleus, the glycogen helix is poorly developed and usually filled with membranes (Figure 5G, H). In this region of the midpiece, the matrix component of the mitochondrial derivative is lamellar in appearance (Figure 5G, H). Further posteriorly the glycogen helix becomes prominent (and partly filled with granular de- posits, Figure 5D, I, J), but is absent in the most distal region of the midpiece (Figure 5K). Organization of matrix and paracrystalline components of the mitochondrial de- rivative is as described for other Doridoidea. Unfortunately the midpiece-glycogen junction was not observed in lon- gitudinal section. Occasionally, transverse sections were obtained showing the 9+2 axoneme surrounded by nine granular blocks, each associated with an adjoining axo- nemal doublet (Figure 5L). It seems possible that these are transverse sections through a cap-shaped structure (? modified annulus) similar to those noted previously for Chromodoris annae (Figure 1L) and Tambya cf. oliva. Sper- matozoa of phyllidiids range in length from 165-175 wm (Phyllidiopsis cardinalis) to 310-340 um (Phyllidia nobilis) (Table 1). AEOLIDOIDEA FACELINIDAE [Pteraeolidia ianthina (Angas) | Acrosome The apical vesicle is small (0.09 um long, 0.06 wm wide) and lies at the anterior extremity of the acrosomal pedestal (Figure 6B Inset). The pedestal of Pteraeolidia ianthina Page 147 (total length 2.3 wm) is extensively intertwined with the nuclear keels (Figure 6A-H). Nucleus The nucleus is short (4.4 um), with a maximum of three or four helical keels posteriorly (decreasing to a single keel near the nuclear apex). The overlap between the acrosomal pedestal and the nucleus has already been described. Transverse and longitudinal sections through the base of the nucleus show that the coarse fibers are closely applied to the axonemal doublets (Figure 6I-M). Within and im- mediately outside the nuclear invagination, each doublet is connected to its adjoining doublets (Figures 6M, 7A). A solid, conical centriolar derivative occupies the innermost recess of the basal invagination of the nucleus (Figure 6I, J). To this structure are attached the coarse fibers (peri- odicity 55 nm) and the central pair of axonemal micro- tubules, the latter seemingly lacking any lumen (Figure 6I-M). A diffuse, distal accessory sheath surrounds the central pair of axonemal microtubules, both within the basal invagination of the nucleus (Figure 6K—M) and in the neck region of the midpiece (Figures 6L—M, 7A, B). Midpiece The neck region is characterized by deposits of mem- branous material (Figure 7A), pockets of unorganized dense granules (Figure 7B), and the axoneme/coarse-fiber com- plex, surrounded by outlying layers of paracrystalline ma- terial. A subnuclear ring is usually visible. Further pos- teriorly (Figure 7C-G) the following changes in midpiece structure occur: (1) the dense granules are organized into a single helix (glycogen helix); (2) the matrix material is helically subdivided; and (3) paracrystalline material forms the inner (periaxonemal) and outer walls of the mito- Figure 4A-G: Figure A, B, Gymnodoris sp.; Figure C-G, Kaloplocamus yates Figure 4A. LS acrosomal complex, nucleus, and proximal region of midpiece. Arrows indicate subnuclear ring (x 13,300). Figure 4B. LS acrosomal complex. Note banded and unbanded portions of acrosomal pedestal. Inset: acrosomal vesicle ( X 56,000). Figure 4C. LS acrosomal complex (with vesicle shown inset). Coarse banding of pedestal clearly visible (x 56,000). Figure 4D. LS anterior region of midpiece showing glycogen helix and subdivided matrix material (x 32,000). Figure 4E. LS junction of nucleus (fibrous) and midpiece. Arrows indicate subnuclear ring (x 32,000). Figure 4F. TS midpiece and glycogen piece (x 45,500). Figure 4G. LS junction of midpiece and glycogen piece. Note annulus (50,000). Abbreviations: a, acrosomal complex; an, annulus; ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; das, distal accessory sheath; gh, glycogen helix; gp, glycogen piece; M, midpiece; ma, matrix material; n, nucleus; p, paracrystalline material. Page 148 The Veliger, Vol. 34, No. 2 J. M. Healy & R. C. Willan, 1991 chondrial derivative, enclosing matrix, glycogen helix, ax- oneme, and coarse fibers. Aside from the glycogen helix, a secondary helix, formed only of the matrix and para- crystalline materials, occurs in the midpiece (Figure 7C- F). Towards the posterior region of the midpiece, the sec- ondary helix is lost and the glycogen helix becomes greatly reduced in size (Figure 7E). Figure 7 (H, I) shows that the glycogen helix also ultimately disappears and that the axoneme is replaced by a deposit of fine granular material and packed membranes. In what is presumed to be close to the terminal region of the spermatozoon, the lumen of the midpiece is unoccupied. Although the midpiece is usu- ally enclosed by the mitochondrial and plasma membranes (Figure 7F, G), spermatozoa lacking these membranes were also observed (Figure 7B, D top). No-evidence of a glycogen piece or annulus could be found even after many hours of observation. Nevertheless in the absence of lon- gitudinal sections through the terminal region of sper- matozoa, we cannot unequivocally state that a glycogen piece or annulus is absent in Pteraeolidia ianthina. Total sperm length in Pteraeolidia tanthina is 390-395 um. GLAUCIDAE [TEM: Glaucilla marginata Bergh, Glaucus atlanticus Forster; Light microscopy: Austraeolis ornata (Angas) ], AEOLIDIIDAE [TEM: Aeolidiella indica Bergh; Light microscopy: Aeolidiella alba Risbec], FACELINIDAE (TEM: Favorinus japonicus Baba] Results for Glaucilla marginata, Glaucus atlanticus, and Aeolidiella indica closely agree with those presented above for Pteraeolidia ianthina. The acrosomal complex features a small acrosomal vesicle and intertwining of the pedestal with a strongly keeled, short nucleus (Figures 6N-R, 7K). The midpiece shows a single glycogen helix, at least one Page 149 secondary helix (anteriorly), and helically organized ma- trix material (Figure 7J, L). In Aeolidiella indica, sper- matozoa with two axonemes and two or three glycogen helices were sometimes observed (Figure 7L, M). Such duplication of sperm components is not considered by us as evidence of true sperm dimorphism, but rather it is almost certainly the result of spermiogenic abnormalities. Favorinus japonicus differs from Pteraeolidia ianthina, Glaucidae, and Aeolidiidae principally in having less pro- nounced overlap between the acrosomal pedestal and nu- cleus (Figure 8C). The acrosomal vesicle of Favorinus ja- ponicus is small (0.07 wm diameter, Figure 8B), the nucleus is strongly keeled (Figure 8A), and the matrix component of the mitochondrial derivative is clearly subdivided into equal-sized, helical tracts (Figure 8D). FLABELLINIDAE [Flabellina rubrolineata (O’ Donoghue) | Spermatozoa of Flabellina rubrolineata also show exten- sive overlap of the pedestal and the nucleus. However, instead of sheathing the anterior region of the nucleus (observed in the Facelinidae, Aeolidiidae, and Glaucidae), the pedestal component of the Flabellina rubrolineata ac- rosomal complex (length 1.8-2.0 um) is largely contained within a deep, lateral groove of the nucleus (Figure 8E- G). Anteriorly, the pedestal emerges to support an ovoid acrosomal vesicle similar in size (0.09 um long, 0.7 um wide) to those occurring in the Aeolidiidae, Facelinidae, and Glaucidae (Figure 8E, inset). Flabellina rubrolineata differs from other aeolidoids in possessing a slightly longer nucleus (6.8-7 um, with only a single keel, Figure 8H), a midpiece without secondary helices (Figure 8I-K), and in the persistence of the axonemal components into the terminal region of the midpiece (Figure 8L). As observed in other aeolidoids, the basal invagination of the nucleus Figure 5A-L: Figure A-D, Phyllidiopsis cardinalis: Figure E-L, Phyllidia nobilis Figure 5A. LS acrosomal complex and nuclear apex (73,000). Figure 5B. LS nuclei and proximal portion of the midpiece (x 5,500). Figure 5C. LS showing flexibility of acrosomal pedestal (x 54,700). Figure 5D. TS midpiece region, and (arrow) terminal region of spermatozoon (x 46,500). Figure 5E. LS through acrosomal complex (Xx 30,000). Inset: TS of acrosomal pedestal ( x 42,000). Figure 5F. LS junction of nucleus and midpiece. Subnuclear ring indicated by arrows (x 42,000). Figure 5G, H. TS Proximal portion of midpiece (x 51,000). Figure 51. LS detail of midpiece (x 40,000). Figure 5J. LS midpiece showing glycogen helix (x 27,000). Figure 5K. Oblique TS midpiece showing paracrystalline material (58,500). Figure 5L. TS showing terminal region of spermatozoa (?annulus, glycogen piece). Nine wedge- shaped components surround the axonemal doublets (x 60,000). Abbreviations: ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; gh, glycogen helix; M, midpiece; ma, matrix material; n, nucleus; p, paracrystalline material. Page 150 The Veliger, Vol. 34, No. Figure 6A-R: Figure A-M, Pteraeolidia ianthina; Figure N-Q, Glaucilla marginata; Figure R, Aeolidiella indica Figure 6A. LS acrosomal pedestal, nucleus (with helical keels) and proximal portion of midpiece (x 20,000). J. M. Healy & R. C. Willan, 1991 is well developed (depth 0.7 wm) with the centriolar de- rivative, coarse fibers, and distal accessory sheath occu- pying the invagination (Figure 81). Figure 81 also shows the presence of a subnuclear ring. Periodicity of banding of the nine coarse fibers (surrounding the axonemal dou- blets) is 40 nm in Flabellina rubrolineata. Figure 8L shows the only observed longitudinal section (here oblique) of the midpiece-glycogen piece junction in Flabellina rubro- lineata. Although the entire glycogen piece is not illus- trated, the micrograph suggests that the axoneme does not enter this region, and that dense granules (putative gly- cogen) comprise the bulk of the glycogen piece. The fact that no transverse sections were obtained through the gly- cogen piece strongly suggests that it comprises a minute proportion of the entire Flabellina rubrolineata spermato- zoon. The dense collarlike structure shown in Figure 8L is probably a form of annulus. Mature sperm length in the Aeolidoidea ranges from 160-170 um in Glaucus atlanticus to 390-395 wm in Pterae- olidia 1anthina (for comparison, see Table 1). DENDRONOTOIDEA [TEM: LOMANOTIDAE—Lomanotus vermiformis Eliot; TEM: HANCOCKIIDAE—Hancockia sp.; TRITONII- DAE—TEM: Maranina rosea (Provot-Fol); Light mi- croscopy: Marianina cyanobrachiata (Ruppell & Leuck- art)] Numerous differences exist between spermatozoa of the three dendronotoids examined—too many in fact to select a “type” for description. Acrosomal Complex In Lomanotus vermiformis and Hancockia sp., the acro- somal vesicles are large (Lomanotus vermiformis—O.56 wm long, 0.14 um wide; Hancockia sp.—0.22 wm long, 0.17 um wide) and set on short (0.2-0.25 um long) wide ped- estals at the nuclear apex (Figure 9A-C, F’). Whereas the acrosomal vesicle of Hancockia sp. is spherical with ho- Page 151 mogeneously electron-dense contents (Figure 9F), the ves- icle of Lomanotus vermiformis is elongate and shows some differentiation of internal contents (enhanced electron den- sity of basal and peripheral areas) (Figure 9A, B). In contrast to Lomanotus vermiformis and Hancockia sp., the acrosomal complex of Marianina rosea consists of a small ovoid acrosomal vesicle (0.09 um long, 0.08 wm wide) connected to the finely tapered apex of the nucleus by a minute (0.1 wm long), wedge-shaped pedestal (Figure 9G, inset). Nucleus The fibrous nature of the nucleus in Lomanotus vermi- formis (Figure 9C) may be the result of osmotic stress, despite the apparently good fixation of other components (see pp. 155, 156 for discussion of this phenomenon in other nudibranchs). Nuclei of Hancockia sp. are helically coiled, but show no evidence of helical keels. In contrast, the nucleus of Marianina rosea exhibits one major helical keel and two or three minor keels (Figure 9G), and in overall shape resembles nuclei of the Aeolidoidea rather than other Dendronotoidea. The basal invagination in all examined Dendronotoidea is shallow (0.4-0.45 um) and occupied by the centriolar derivative (Lomanotus vermifor- mis, Figure 9C) or the centriolar derivative and adjoining portion of the axoneme/coarse-fiber complex (Marianina rosea, Hancockia sp.—Figure 91). A subnuclear ring is present in all three dendronotoid species (see Figure 91). Midpiece Aside from the differences in nuclear shape noted above, Lomanotus vermiformis, Hancockia sp. and Marianina rosea also show marked differences in midpiece morphology. In Lomanotus vermiformis, the glycogen helix within the im- mediate post-nuclear region of the midpiece is very well developed, though filled with membranes rather than gran- ular deposits (Figure 9C, D). The glycogen helix in Han- cockia sp. and Marianina rosea is less removed from the main body of the midpiece (Figure 9G, I). Marianina rosea Figure 6B. Detail of pedestal and nucleus of Figure 6A (X43,200). Inset: acrosomal vesicle supported by pedestal at nuclear apex (x 77,000). Figure 6C-H. TS anterior-posterior sequence showing intertwining of pedestal and nucleus (C— G x48,000; H x 38,400). Figure 61. LS junction of nucleus and midpiece (x 44,000). Figure 6J-M. TS anterior to posterior sequence showing structural changes from centriolar de- rivative to axoneme/coarse-fiber complex. Note helical keels of nucleus (x 40,000). Figure 6N. LS acrosomal vesicle, portion of pedestal, and nuclear apex (x 64,000). Figure 60-Q. TS anterior-posterior sequence showing changes in shape of intertwined pedestal and nucleus (xX 80,000. Figure 6R. TS pedestal and nuclear keel (x 60,000). Abbreviations: ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; gh, glycogen helix; k, nuclear keels; M, midpiece; n. nucleus. Page 152 The Veliger, Vol. 34, No. 2 Figure 7A—M: Figure A-I, Pteraeolidia ianthina; Figure J-K, Glaucilla marginata; Figure L-M, Aeolidiella indica Figure 7A, B. TS neck region of midpiece. Coarse fibers attached to axonemal doublets. Distal accessory sheath envelops central tubules of axoneme (54,500). J. M. Healy & R. CG. Willan, 1991 is also notable in having well defined, helical subdivisions within the matrix material (Figure 9G, I) (also present in Hancockia sp. and Lomanotus vermiformis, but less appar- ent). A subnuclear ring was present in all three dendron- otoid species studied (for example, Figure 9G). Glycogen Piece No information on the midpiece/glycogen-piece junc- tion could be obtained for any of the three dendronotoids studied. In Lomanotus vermiformis, however, transverse sec- tions revealed that the axoneme continues intact from the midpiece into the glycogen piece (where it is surrounded by putative glycogen deposits), but soon thereafter degen- erates from a 9+2 configuration into singlet microtubules (Figure 9E). Available data for Lomanotus vermiformis sug- gest that the glycogen piece is short, probably less than 2 um long. Mature spermatozoa of the Dendronotoidea range from 200-230 um in Lomanotus vermiformis to 320-330 um in Marianina rosea. ARMINOIDEA (DORIDOMORPHIDAE—Doridomorpha gardineri Eliot; ARMINIDAE—Dermatobranchus fortunata Bergh) Doridomorpha gardinert The acrosomal pedestal is 0.36-0.4 um long, sheaths the tapered apex of the nucleus, and apically, supports a small (0.08 wm long, 0.65 wm wide) acrosomal vesicle (Figure 9J). A small cavity near the base of the pedestal is sometimes observed in longitudinal sections (Figure 9 J). The length of the nucleus could not be determined. How- ever, it is circular in transverse profile, and has a mod- erately deep (0.66 um) basal invagination which houses the centriolar derivative, distal accessory sheath, and initial portion of the axoneme/coarse-fiber complex (Figure 9L). The distal accessory sheath (length 0.4 um) is penetrated Page 153 by the central microtubules of the axoneme (Figure 9L). Periodicity of primary banding of the coarse fibers is 52 nm. A subnuclear ring is present (Figure 9L). Within the midpiece, matrix materials are organized into clearly defined helical tracts (Figure 9L). A glycogen helix and secondary helix are present (Figure 9K). Axo- nemal microtubules persist to the midpiece/glycogen-piece junction, but do not enter the glycogen piece. A simple ring-shaped annulus is present at the junction (Figure 9M). The glycogen piece is 0.4-0.5 um long and consists of granular deposits and the plasma membrane (Figure 9M). Dermatobranchus fortunata (not illustrated) Spermatozoa of this species differ from those of Dori- domorpha gardinert principally in having more extensive overlap between the acrosomal pedestal and the nucleus and well developed nuclear keels. Table 2—Summary Comparative ultrastructural features of nudibranch spermatozoa examined in this study are listed in Table 2, and whole sperm lengths are given in Table 1. DISCUSSION Nudibranch Spermatozoa: Comparison With Other Gastropods Spermatozoan morphology varies widely within the Gastropoda. In the Prosobranchia, for example, sperma- tozoa may be comparatively simple in structure (e.g., ex- ternally fertilizing archaeogastropods) or complex and of- ten dimorphic (most internally fertilizing groups such as Neritimorpha, Caenogastropoda) (FRANZEN, 1955; NISHI- WAKI, 1964; GrusTI & SELMI, 1982; KOHNERT & STORCH, 1984; KoIKE, 1985; HEALY, 1988a). Figure 7C, D. TS proximal region of midpiece. Note secondary helix, and at top, spermatozoon without investing plasma or mitochondrial membranes (x 46,400). Figure 7E. TS middle region of midpiece (x 48,000). Figure 7F. LS middle region of midpiece (x 48,000). Figure 7G. LS near proximal region of midpiece (20,000). Figure 7H. TS distal region of midpiece (x 52,000). Figure 7I. LS terminal region of midpiece (axoneme replaced by dense granules) (x 48,000). Figure 7J. TS midpiece (x 32,000). Figure 7K. TS base of nucleus (x 32,000). Figure 7L. TS midpiece with two glycogen helices (x 24,000). Figure 7M. TS biaxonemal spermatozoon with three glycogen helices (x 24,000). Abbreviations: cf, coarse fibers; das, distal accessory sheath; gh, glycogen helix; ma, matrix material; n, nucleus; p, paracrystalline material; sh, secondary helix. The Veliger, Vol. 34, No. 2 Page 154 J. M. Healy & R. C. Willan, 1991 Spermatozoa of the Nudibranchia clearly show all the features of other opisthobranch and pulmonate sperma- tozoa outlined by HEALY (1983, 1988a), namely a dis- tinctive form of acrosomal complex (round/oblong acro- somal vesicle plus a column-shaped pedestal), a nucleus (usually with one or more helical keels), and a complex midpiece (mitochondrial derivative enclosing axoneme, coarse fibers, and at least one glycogen-filled helix) (sum- marized in Figure 10A-E). The neck region of nudibranch spermatozoa, like that observed in most other heterobranchs, features a pluglike centriolar derivative continuous with the banded coarse fibers and the axoneme, a distal accessory sheath, and subnuclear ring (Figure 10D). Similarly, the helical mi- tochondrial derivative, with its lattice-like paracrystalline layers and enclosed axoneme, coarse fibers, and glycogen helix, is essentially as observed in other heterobranch sper- matozoa (Figure 10B, E) (for comparison see ANDERSON & PERSONNE, 1967, 1976; OHsako, 1971; THompson, 1973; Ritter & ANDRE, 1975; Kitajima & PARAENSE, 1976; MaxweELL, 1976, 1980; Dan & Takaicul, 1979; ATKINSON, 1982; ReGER & FITZGERALD, 1982; HeEa.y, 1983, 1986, 1988a, b; HEaLty & WiLian, 1984; HEaLy & JAMIESON, 1989; Sumikawa & Funakosul, 1984; SELMI et al., 1988). Although spermatozoa of nudibranchs consistently show poor development of the glycogen piece (absent in some taxa: for comparison see Figure 10K-N), this has previ- ously been demonstrated in the Notaspidea (HEALY & WILLAN, 1984), Pyramidelloidea (HEaLy, 1988b) and An- aspidea (HEaLy, 1984). Enclosure of substantial glycogen Page 155 deposits within the mitochondrial derivative may obviate the need for a well-developed glycogen piece (THompson, 1973; Heaty & WILLAN, 1984; see also MAXWELL, 1980, for discussion of glycogen in heterobranch spermatozoa). Absence of the midpiece membranes in some nudibranchs (for example in some spermatozoa of Pteraeolidia ianthina, herein) has been noted previously in aplysiids (BEEMAN, 1973, loss of plasma membrane only) and in basomma- tophorans (ACKERSON & KOEHLER, 1977, loss of plasma and mitochondrial membranes). Such membrane loss could be a normal maturational or capacitational phenomenon (BEEMAN, 1973; ACKERSON & KOEHLER, 1977), or the result of imperfect cell fixation. Further work on mem- brane substructure and function in heterobranch sper- matozoa seems necessary in order to clarify this issue. In summary, it was surprising that the present study failed to find sperm components that were new or specif- ically restricted to the Nudibranchia. Autosperm and Allosperm In the present study we have examined only the auto- sperm (7.e., endogenous sperm) of each species (either those occurring in the ovotestis or the hermaphrodite duct and ampulla). Work by THompson (1966, 1973) on allosperm (z.e., exogenous sperm) of Archidoris pseudoargus and more recently by MEDINA et al. (1988b) on allosperm of Hyp- selodoris messinensis (Ihering) has demonstrated that, at least within the receptaculum seminis, no noticeable changes in the ultrastructure of sperm components have taken place after sperm transfer (acrosomal complex, nucleus, and Figure 8A—L: Figure A—D, Favorinus japonicus; Figure E-L, Flabellina rubrolineata Figure 8A. LS nucleus (note keel) and proximal portion of midpiece (x 14,200). Figure 8B. LS showing acrosomal vesicle and apex of pedestal of immature spermatozoon (acrosomal complex still associated with support structures). ( < 63,000). Figure 8C. TS through posterior region of pedestal of immature sperm (63,000). Inset: TS through pedestal and nucleus of mature spermatozoon (x 63,000). Figure 8D. LS midpiece showing helical subdivision of matrix material (x 30,000). Figure 8E. LS acrosomal complex and nuclear apex. Note that the posterior portion of the pedestal is inserted into a deep nuclear invagination. Inset: acrosomal vesicle and tip of pedestal ( x 60,000). Figure 8F, G. TS showing enclosure of acrosomal pedestal in nuclear groove (x 65,250). Figure 8H. LS posterior portion of nucleus, showing keel (x 20,200). Figure 8I. LS junction of nucleus and midpiece. Subnuclear ring indicated by arrows (x 38,250). Figure 8J. LS midpiece (x 36,500). Figure 8K. TS midpiece (50,250). Figure 8L. LS junction of terminal portion of midpiece and glycogen piece (x 54,700). Abbreviations: ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers;-das, distal accessory sheath; gh, glycogen helix; gp, glycogen piece; k, nuclear keel; M, midpiece; n, nucleus. The Veliger, Vol. 34, No. 2 Page 156 J. M. Healy & R. C. Willan, 1991 midpiece still intact). Spermatozoa within the bursa cop- ulatrix, however, are always degenerate (THompson, 1966; SCHMEKEL, 1971; MEDINA et al., 1988a). HOLMAN (1972) reported that the reacted acrosome of Acanthodoris pilosa (Miller) (allosperm) was characterized by rolled back membranes and an “expanded” form. Unfortunately no micrographs were provided by Holman to support this observation. To our knowledge the acrosome reaction re- mains to be demonstrated in auto- and allosperm of het- erobranch gastropods. In the present study we noted in a number of species that spermatozoa taken from the her- maphrodite duct had nuclei that were clearly fibrous in substructure and often inflated in shape (e.g., Hexabran- chus sanguineus, Asteronotus cespitosus, Kaloplocamus yates1, Rostanga arbutus), whereas mature or almost mature sperm nuclei from the ovotestis of the same animals were con- densed and uniformly electron-dense. Although we as- sumed at first that this may be due to fixative osmolarity, fibrous nuclei only occurred in certain species within each processing run (phyllidiids and most aeolidoids, for ex- ample, were not affected), and other sperm components showed little evidence of osmotic stress. Previous authors, employing a range of fixation schedules, have demonstrated the same phenomenon in other nudibranchs (SCHMEKEL, 1971; HOLMAN, 1972; THompson, 1966, 1973; MEDINA et al., 1988b), in cephalaspids (THompson, 1973; HEALY unpublished) and in onchidiid and siphonariid pulmonates (HeEaty, 1983, 1986; Sumikawa & FunakosHl, 1984; AZE- VEDO & CORRAL, 1985; SELMI et al., 1988). A full expla- Page 157 nation as to why fibrous sperm nuclei occur in these eu- thyneuran gastropods has yet to be advanced. AZEVEDO & Corra (1985) suggest that complete dehydration of sperm nuclei of S¢phonaria algesirae Quoy & Gaimard may not be a prerequisite for gamete maturation. However, it has been shown that immature (testicular) sperm nuclei of other siphonariids and nudibranchs are fully condensed (see Figures of HEALY, 1983; MEDINA et al., 1988b; this account). MEDINA e¢ al. (1988b) refer to the fibrous (ma- ture) nuclei of Hypselodoris messinensis as ‘“‘decondensed,” but could not offer any functional reason for the phenom- enon. SELMIet al. (1988) have suggested that this condition, as observed by them in Onchidiella celtica (Cuvier), could prove to be due to low levels of protamines in mature sperm nuclei, or may even be an expression of sperm dimorphism. It is possible that pH may also be involved in changes in nuclear substructure. HOLMAN (1972), for example, observed that short periods of motility (2-5 min) could sometimes be induced in allosperm of Acanthodoris pilosa by exposure to alkaline seawater. During motility the sperm “head” became swollen, then the tail detached. Significantly no structural changes were observed in au- tosperm (all non-motile) subjected to the same treatment. Holman concluded that autosperm and allosperm of Acan- thodoris pilosa may differ physiologically, and possibly may show structural differences in permeability of the plasma membrane. Clearly much cytochemical work needs to be carried out to determine the true cause of fibrous sperm nuclei in nudibranchs and other heterobranch gastropods. Figure 9A-M: Figure A-E, Lomanotus vermiformis; Figure F, G, Hancockia sp.; Figure H, I, Marianina rosea; Figure J-M, Doridomorpha gardineri Figure 9A, B. LS acrosomal complex and nuclear apex (x 56,000). Figure 9C. LS showing acrosomal complex, nucleus (fibrous, inflated), and initial region of mid- piece. TS of midpieces also visible (x 18,000). Figure 9D. TS proximal portion of midpiece. Note positioning of glycogen helix (x 47,250). Figure 9E. TS through terminal region of midpiece (at right) and glycogen piece (with intact axoneme, and with axoneme reduced to singlet microtubules) (x 45,500). Figure 9F. LS acrosomal complex and nuclear apex (x 40,000). Figure 9G. Junction of nucleus and midpiece. Arrows indicate subnuclear ring (x 26,000). Inset: LS acrosomal complex and nuclear apex (x 55,300). Figure 9H. TS nucleus of slightly immature spermatozoon showing keel (x 28,700). Figure 9I. LS anterior region of midpiece showing helical subdivisions of matrix (x 21,000). Inset: TS of midpiece (x 28,000). Figure 9J. LS acrosomal complex and nuclear apex (56,000). Figure 9K. TS midpiece (x 40,000). Figure 9L. LS junction of nucleus and midpiece. Subnuclear ring indicated by arrows (x 40,400). Figure 9M. LS junction of midpiece and glycogen piece (x 53,000). Abbreviations: a, acrosomal complex; an, annulus; ap, acrosomal pedestal; av, acrosomal vesicle; cd, ceniriolar derivative; cf, coarse fibers; das, distal accessory sheath; gh, glycogen helix; gp, glycogen piece; k, nuclear keel (s); M, midpiece; ma, matrix material; n, nucleus; p, paracrystalline material. The Veliger, Vol. 34, No. 2 Page 158 J. M. Healy & R. C. Willan, 1991 Sperm Dimorphism ROGINSKAYA (1964) reported dimorphic sperm nuclei in seven species of Coryphella (=Flabellina sensu MILLER, 1971) from the White, Barents, and Okhotsk seas (C. rufibranchialis Johnston, C. fusca O’ Donoghue, C. athadona Bergh, and four unnamed species), but only a single type of sperm nucleus in 21 other nudibranch species (repre- senting the Doridoidea, Dendronotoidea, and other species of Aeolidoidea). Sperm nuclei of the seven Coryphella spe- cies were found to be either short and curved (referred to as “typical sperm” by ROGINSKAYA, 1964) or long and helically coiled (referred to as “atypical sperm’). Both types of nucleus reacted positively to nuclear stains (Feul- gen, Heidenhain’s iron hematoxylin). According to Roginskaya, only “typical” sperm are transferred during copulation, while “atypical” sperm are retained within penis indicating that “atypical” sperm are not involved in fertilization. Roginskaya also examined spermatozoa of other genera of the Flabellinidae (Flabellina, Chlamylla) but only found a single type of spermatozoon, and con- cluded that sperm dimorphism in Coryphella supported the need for a separate family for this genus (z.e., Coryphel- lidae as distinct from Flabellinidae). Unfortunately this work has never been followed up using electron micros- copy. SCHMEKEL (1971) included some TEM micrographs of ovotestis sperm from Coryphella pedata (Montague) in her review of nudibranch reproductive systems, but was evidently unaware of ROGINSKAYA’s (1964) work and its significance. Her published micrographs, however, while not providing any ultrastructural evidence to support sperm dimorphism in Coryphella, do help to establish that sper- Page 159 matozoa of Coryphella are very similar to those of Flabel- lina. Our work on Flabellina rubrolineata indicates only a single type of sperm in this species, which is consistent with Roginskaya’s light microscopic observations on Fla- bellinopsis 1odinea (Cooper). Aside from ‘THOMPSON’s (1973) light microscopic ob- servation that the acrosomes of Dendronotus iris Cooper may be either straight or helical, and ROGINSKAYA’s (1964) findings (discussed above), we are unaware of any other reported incidence of sperm dimorphism in the Nudi- branchia. Rare biaxonemal spermatozoa showing multiple glycogen helices such as we have demonstrated for Aeolidiella indica (see Figure 7M) are probably products of abnormal spermiogenesis and not examples of true sperm dimorphism. Certainly the profound structural dimor- phism observed in spermatozoa of internally fertilizing prosobranchs (for recent reviews see GIUSTI & SELMI, 1982; HEALY, 1988a) is not encountered in the Nudi- branchia or any other group of heterobranch gastropods. Comparisons Within the Nudibranchia Results of our comparative study support TTHOMPSON’s (1973) statement that despite similarities in general mor- phology, spermatozoa of nudibranchs do show marked variation among taxa in the shape, substructure, and size of the acrosome (vesicle and pedestal components) (Figure 11). This study also reveals notable differences among genera and families in the shape of the nucleus (short or long, keeled or lacking keels, variation in depth of basal invagination), the spatial relationship of the acrosomal pedestal with the nucleus (distinct, overlapping, inserted Figure 10 A-N. Summary of sperm ultrastructural features in the Nudibranchia Figure 10A—-E: Chromodoris annae. Figure 10A. Positioning of the acrosomal complex, nucleus, midpiece (here greatly shortened), and terminal region (x 1,750). Figure 10B. Acrosomal complex, nucleus, and proximal region of midpiece (x 12,000). Figure 10C. Detail of acrosomal complex and nuclear apex (x 40,000). Figure 10D. Detail of nucleus-midpiece junction (x 40,000). Figure 10E. TS midpiece showing distribution and organization of paracrystalline and matrix components and glycogen helix (x 60,000). Figure 10F—J. Morphological variation in nudibranch sperm nuclei (F, Rostanga arbutus; G, Sclerodoris cf. apiculata; H, Phyllidiopsis cardinals; 1, Pteraeolidia 1tanthina; J, Favorinus japonicus) (x 12,000). Figure 10K-N. Morphological variation in the midpiece-glycogen piece junction in nudibranch sperm (K, Doriopsis granulosa; L, Doridomorpha gardinerr, M, Chromodoris annae (dense cap may be modified annulus); N, Jorunna pantherina) (x 35,000). Abbreviations: a, acrosomal complex; an, annulus; ap, acrosomal pedestal; av, acrosomal vesicle; cd, centriolar derivative; cf, coarse fibers; das, distal accessory sheath; gh, glycogen helix; gp, glycogen piece; M, midpiece; ma, matrix material; n, nucleus; p, paracrystalline material; sh, secondary helices. Page 160 The Veliger, Vol. 34, No. 2 Hypselodoris Jorunna Rostanga Chromodoris Dendrodoris Phyllidia Phyllidiopsis \ >. I 1 Lomanotus Gymnodoris Hancockia Pteraeolidia Flabellina Figure 11 Comparative morphology of the acrosomal complex in the Nudibranchia (all x 40,000). Abbreviations: ap, acrosomal pedestal; av, acrosomal vesicle; n, nucleus. J. M. Healy & R. C. Willan, 1991 or intertwined), organization of the midpiece (secondary helices present or absent, shape of glycogen helix, orga- nization of matrix component), and the morphology of the glycogen piece (distribution of granules, presence or ab- sence of axonemal microtubules, shape of annulus) (Figure 10F-N). Unfortunately we could not find any sperm features that clearly defined the Nudibranchia. Within the order, how- ever, spermatozoa provide information that may help in the determination of relationships among genera, families, and possibly superfamilies. Acrosomal Complex and Nucleus Morphology of the acrosomal complex and nucleus ap- pears to be consistent within genera and/or families, al- though at the superfamily level it is sometimes impossible to identify features diagnostic of a particular group (e.g., the Doridoidea) (Figures 10F-J, 11). The Aeolidoidea show pronounced overlap between the acrosomal pedestal and the nucleus (achieved by inter- twining in the Glaucidae, Facelinidae, and Aeolidiidae, and by insertion of the pedestal in a long nuclear groove in the Flabellinidae) as well as a small, spherical acrosomal vesicle. The Arminoidea (Doridomorpha gardineri) also possess a small, spherical acrosomal vesicle, but the degree of ped- estal overlap with the nucleus in this species is no greater than that occurring in many Doridoidea. Marked variation in the size and shape of the acrosomal complex occurs in the Dendronotoidea. The large size of the acrosomal vesicle in Lomanotus vermiformis and Han- cockia sp. suggests a connection between the Dendrono- toidea and Doridoidea. Marianina rosea, in contrast, shows nuclear and acrosomal features more consistent with those of the Aeolidoidea than other Dendronotoidea. Clearly there is a need for additional information on the sper- matozoa of Dendronotoidea, particularly the Dendrono- tidae (one species of which reputedly shows dimorphic acrosomal morphology [Dendronotus iris—see THOMPSON, 1973]) and the Tritoniidae. The Doridoidea show remarkable variation between taxa in the structure of the acrosomal complex, nucleus, and glycogen piece (Figures 10, 11). Two basic types of ac- rosomal morphology can be recognized within this super- family: (1) large acrosomal vesicle set on a short, squat pedestal, with nil or slight overlap between pedestal and nucleus (Hexabranchus sanguineus, Doris verrucosa, Aster- onotus cespitosus, Sclerodoris cf. apiculata) and (2) medium- sized acrosomal vesicle set on a tapered pedestal, with marked overlap between pedestal and nucleus (all other investigated Doridoidea) (Figure 11). Within the second category, pedestal substructure and length are variable. In Chromodoris spp., Rostanga arbutus (this account), and Hypselodoris spp. (MEDINA et al., 1988a, b), the pedestal shows fine striations. Pedestals of Kaloplocamus yatest (Polyceridae) and Gymnodoris sp. (Gymnodorididae) are remarkable in their pronounced length (longer than all Page 161 other nudibranchs) and coarsely banded substructure— features that suggest close affinities between the Gymno- dorididae and Polyceridae. In the Phyllidiidae, the acro- somal vesicle is oblong rather than spherical, and the ped- estal is slender. Phyllidiid spermatozoa differ from other Doridoidea in possessing a moderately long, straight nu- cleus (twice to four times the length of most other dorid nuclei, Figure 10). Sperm nuclei of Doriopsis granulosa are also long (12-15 wm) but are helically coiled (like other Doridoidea). Aside from reflecting systematic relationships, the ob- served variations in the size of the acrosomal vesicle and length/shape of the pedestal within the Doridoidea are probably also connected with egg morphology (size, yolk content, width of vitelline layer). We cannot, at this stage, confirm any structural correlation between nudibranch sperm and eggs, but note that FRANZEN (1983) has found a positive correlation between nuclear elongation and yolky eggs in the Bivalvia. Neck Region, Midpiece Most variation in the neck region (nucleus-midpiece junction) of nudibranch spermatozoa centers on the depth of the basal invagination of the nucleus. This invagination is relatively deeper in the Aeolidoidea than in other nu- dibranchs, with the axoneme/coarse-fiber complex in- truding into the nuclear invagination. In contrast, the ax- oneme/coarse-fiber complex of some Doridoidea (e.g., Kaloplocamus yatesi, Lomanotus vermiformis, Gymnodoris sp.) commences outside the poorly developed nuclear in- vagination. The midpiece, which forms the bulk of the nudibranch spermatozoon, is extremely variable in length, ranging from 125 wm in Miamira magnifica to a maximum of 590- 615 wm in Doriopsilla miniata. It is interesting to note that midpiece and total sperm length vary even within well defined genera (see Table 1, and THOMPSON, 1973). Sperm or midpiece length may eventually prove useful in resolving problems of species identification, particularly in cases of disputed species status. At the ultrastructural level, the mitochondrial derivative may show one or sometimes two secondary helices in addition to the single glycogen helix incorporated within the derivative. Previously it was be- lieved that nudibranch spermatozoa may universally lack secondary keels (see THOMPSON, 1973; MAXWELL, 1983). Helical subdivision of the matrix component of the deriv- ative is most pronounced in the Aeolidoidea, Arminoidea, and Dendronotoidea, taking the form of well defined tracts. In the Doridoidea, the helical orientation of the matrix is often obscured, though clearly showing compartmentalized substructure. Glycogen Piece, Annulus In all nudibranch species examined at the TEM level, the glycogen piece is either poorly developed or possibly absent (see Figure 10K-N). The axoneme may terminate Page 162 within the midpiece or persist into the glycogen piece. Only in Doriopsis granulosa does the axoneme form the posterior tip of the spermatozoon (Figure 10K). Most commonly the annulus is a simple electron-dense ring associated with the inner surface of the plasma and mitochondrial mem- branes at the midpiece/glycogen-piece junction. The cap- shaped structure forming the terminal tip of some nudi- branch spermatozoa (e.g., Chromodoris annae, Tambya cf. oliva—see Figure 10) may represent a modified annulus. Taxonomic and Phylogenetic Considerations Although the present study failed to find sperm char- acters that specifically define the Nudibranchia, the data obtained do permit some evaluation of existing views on the origins of the group and possible relationships within and between the four superfamilies. We wish to stress, however, that numerous nudibranch taxa remain to be examined and, for this reason, a cladistic analysis of the Nudibranchia using sperm features is not attempted here. Inevitably as more spermatological information becomes available, a clearer pattern of relationships within the Nu- dibranchia should emerge. On the basis of general anatomy, modern authors hold that the Dendronotoidea, Arminoidea and Aeolidoidea, as a group (Cladobranchia), differ markedly from the Dori- doidea (Anthobranchia). MINICHEV (1970) considered that anatomical differences between the Doridoidea and the remainder of the Nudibranchia were great enough to sug- gest independent origins for both groups. SCHMEKEL (1985: 252-253), however, has argued that despite anatomical differences between the Anthobranchia and the Clado- branchia, these two groups are linked by significant apo- morphies (13 chromosome pairs, concentrated nervous sys- tem, loss of albumen gland, presence of cells with “special vacuoles’’) thereby suggesting a common origin for all nu- dibranchs probably from a pleurobranch-like notaspid. Most recently WILLAN (1987) has reviewed the anatomy, classification, and phylogeny of the Notaspidea. He con- cluded that the Notaspidea probably shared a common cephalaspid ancestry with anthobranch nudibranchs rather than directly giving rise to them. Existing sperm data are at least consistent with the view that the Nudibranchia (herein; THOMPSON, 1973; MEDINA et al., 1985-1988) are closely allied to pleurobranch no- taspids (ODHNER, 1939; GHISELIN, 1966; THOMPSON, 1973; GOSLINER & GHISELIN, 1984; HEALY & WILLAN, 1984). So few cephalaspid taxa have been examined for sperm ultrastructure (Acteon tornatilis—THOMPSON, 1973; Ham- inoea simillima Pease, Philine angasi Crosse & Fischer, Tornatina sp.—HEALY, 1982a, 1984) that at present it is impossible to evaluate WILLAN’s (1987) hypothesis of a cephalaspid origin for the Notaspidea and Anthobranchia. Certainly there is no sperm evidence to reject this proposal. Given the specialized features of Umbraculum sinicum (Gmelin) spermatozoa (featuring complex intertwining of nucleus and mitochondrial derivative— THOMPSON, 1973; The Veliger, Vol. 34, No. 2 HEALY & WILLAN, 1984) it seems highly unlikely that the Umbraculidae are ancestral to the Nudibranchia as sug- gested by BOETTGER (1954). Nevertheless a study of 7y- lodina (Tylodinidae) will be necessary to determine wheth- er spermatozoa of the entire superfamily Tylodinoidea are as specialized as those of Umbraculum sinicum. Interestingly, sperm data do lend some support to BOETTGER’s (1954) association of the Dendronotoidea with the Doridoidea rather than with the Arminoidea and Aeco- lidoidea. Spermatozoa of examined species of Dendrono- toidea (species of Hancockiidae, Lomanotidae, and Triton- iidae [Marianinae]) showed marked variation in the size and shape of the acrosomal vesicle and pedestal: Marianina rosea has a very small acrosomal vesicle (similar in size to those of Aeolidoidea and Arminoidea) while in Hancockia sp. and Lomanotus vermiformis the vesicle is well developed (similar to Doridoidea). Given that the Dendronotoidea are universally regarded as a monophyletic group (united by the presence of tubular rhinophoral sheaths—WILLAN, 1988), acrosomal morphology in the three dendronotoids examined may reflect family level differences. Further in- vestigations of sperm ultrastructure should be directed to- wards larger, more “typical” dendronotoids (e.g., species of Dendronotus), particularly since the three species in- cluded in this study are advanced, aeolidiform animals. Within the superfamilies, the Doridoidea seem to be divisible into four groups on the basis of acrosomal and nuclear features: (1) Chromodorididae (Chromodoris spp.), some Dorididae (Jorunna pantherina, Rostanga arbutus, Hypselodoris spp.), Dendrodoridae (Dendrodoris nigra); (2) Gymnodorididae (Gymnodoris sp.), Polyceridae (Kaloplo- camus yatest); (3) Dorididae (Doris verrucosa, Asteronotus cespitosus, Sclerodoris cf. apiculata), Hexabranchidae (Hexabranchus sanguineus); and (4) Phyllidiidae (Phyllidia spp., Phyllidiopsis spp.). If the more prevalent, group 1 acrosomal complex is ancestral for the Doridoidea, then two trends are apparent: one towards an increase in vesicle size and a decrease in pedestal length (group 3) and another towards a decrease in vesicle size and an increase in ped- estal length (group 4, correlated with a substantial increase in nuclear length). On the basis of our data, there are no compelling reasons to associate the Dendrodoridae with the Phyllidiidae (as Porostomata—see SCHMEKEL, 1985). The long, coarsely banded pedestals of group 2 (Gym- nodorididae and Kaloplocamus yates: of the Polyceridae) could be derived readily from a group 1 pedestal (which often shows fine striations). Much additional data are needed for the Doridoidea, particularly the more primitive families and genera (e.g., Bathydoris). The Aeolidoidea can be divided into two groups on the basis of sperm morphology: (1) Flabellinidae; and (2) Fa- celinidae, Glaucidae, Aeolidiidae. These groups correlate with the two major branches of the heteroproct Aeolidi- doidea recognized by SCHMEKEL (1985) (1—Piseinoteci- dae + Flabellinidae; 2—Facelinidae + Aeolidiidae). Ab- sence of sperm data makes it impossible to comment on the relationship between acleioproct aeolidoideans and the J. M. Healy & R. C. Willan, 1991 Heteroprocta, or the view expressed by some authors (e.g., GHISELIN, 1966) that the Aeolidoidea may be polyphyletic. ROGINSKAYA’s (1964) report of sperm dimorphism in Cor- yphella (seven out of seven examined species) has already been mentioned (see “Sperm Dimorphism,” above). If this finding, unique among the Nudibranchia, can be substan- tiated at the ultrastructural level, then familial status for the genus would seem justified (favored by ROGINSKAYA, 1964). If it cannot be confirmed, then the demonstrated similarity of Coryphella sperm (C. pedata—see micro- graphs of SCHMEKEL, 1971) to sperm of Flabellina (F. rubrolineata) would support the currently accepted place- ment of Coryphella within the Flabellinidae. We believe that examination of sperm ultrastructure in Babakina may help determine the correct family placement of this genus (for differing views on the position of Babakina see MILLER, 1974; GOSLINER, 1980). ACKNOWLEDGMENTS A number of people have helped us during the progress of this work. Dr. T. M. Gosliner and Mr. D. Brunckhorst assisted in the collection of specimens while Mrs. L. Dad- dow and Mr. T. Gorringe are thanked for their assistance with electron microscopy and photography respectively. We also thank the reviewers for their constructive com- ments on the manuscript. This project was supported fi- nancially by The Keith Sutherland Award of the Austra- lian Museum, a Special Project Grant from the University of Queensland and a University of Queensland Postdoc- toral Research Fellowship (J.M.H.) and a grant from the Australian Bureau of Flora and Fauna and CSIRO Chris- tensen Research Fellowship (R.C.W). LITERATURE CITED ACKERSON, A. & L. KOEHLER. 1977. Vesiculation and loss of the plasma membrane along the midpiece of Physa sp. sper- matozoon. 35th Annual Proceedings of the Electron Micro- scopical Society of American (Boston):618-619. ANDERSON, W. & P. PERSONNE. 1967. The fine structure of the neck region of spermatozoa of Helix aspersa. Journal de Microscopie (Paris) 6:1033-1042. ANDERSON, W. & P. PERSONNE. 1976. The molluscan sper- matozoon: dynamic aspects of its structure and function. American Zoologist 16:293-313. ATKINSON, J. W. 1982. 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The taxonomy of two host-specific, cryptic dendronotoid nudibranch species (Mollusca: Gastropoda) Page 165 from Australia including a new species description. Zoolog- ical Journal of the Linnean Society 94:39-63. WILLAN, R. C. & N. COLEMAN. 1984. Nudibranchs of Aus- tralasia. Australasian Marine Photographic Index, Sydney. 56 pp. The Veliger 34(2):166-171 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Acochlidium fijiensis sp. nov. (Gastropoda: Opisthobranchia: Acochlidiacea) from Fiji by A. HAYNES anp W. KENCHINGTON School of Pure and Applied Sciences, The University of the South Pacific, P.O. Box 1168, Suva, Fiji Abstract. A new species of freshwater opisthobranch, Acochlidium fijiensis, collected from stones in the Nasekawa River, Vanua Levu, Fiji, is described and its gross anatomical features are discussed and compared with those of other species of Acochlidium. Individual Acochlidium fijiensis reached maturity from July to October when the population was most abundant. Eggs were laid in a jelly mass attached to stones and the young hatched as veligers. INTRODUCTION The Acochlidiacea is the only opisthobranch order in which freshwater species are found and all of these have been discovered on islands. The freshwater species are Strubellia paradoxa (Strubell, 1892) from Guadalcanal, Solomon Is- lands, and Amboina, Indonesia (WAWRA, 1974), Acochlidi- um amboinense Strubell, 1892, from Amboina, Acochlidium weberi Bergh, 1896, from Flores (placed in the new genus, Palliohedyle by RANKIN [1979] but classification disputed by Wawra [personal communication]), Acochlidium suteri Wawra, 1979, from Sumba, Indonesia, Acochlidium bay- erfehlmanni Wawra, 1980, from Palau (WAwRA, 1980), and Jantulum elegans Rankin, 1979, from St. Vincent in the Caribbean (RANKIN, 1979). MATERIALS anpD METHODS Acochlidium fujiensis was first collected 7 km upstream from the mouth of the Nasekawa River at the bridge on the Labasa-Savusavu highway on the island of Vanua Levu, the second largest island in Fiji (site, 16°40’S, 179°16’E) in October 1983 (HAYNES, 1988). Subsequently other Fijian streams and rivers have been searched for this species. The only other place where it has been found is 4 km upstream from the mouth of the Lami River, Viti Levu, the main island of Fiji (site, 18°06’S, 178°24’E). Bernadette Holthuis found 5 specimens of A. fijzensis in the Lami River in November-December 1988. Small A. fijiensis populations may exist elsewhere in Vanua Levu and Viti Levu but, because individuals are well camou- flaged and blend with the stones under which they live, they are difficult to detect. Radulae were dissected from three preserved Acochlidi- um fijiensis. They were cleared with 10% potassium hy- droxide and mounted in glycerine. The penis glands were removed from each dissected specimen, mounted in gly- cerine, and examined under a stereoscopic microscope. For histology, specimens were killed and fixed in Bouin’s fluid. Best results were obtained when the animals were first relaxed by lowering their temperature to about 4°C in the refrigerator. Extended, torpid specimens were im- mersed in ice-cold Bouin’s fluid for 1 hr followed by 24 hr at room temperature. Fixed specimens were washed in running tap water for 12 hr, dehydrated in a graded series of ethanol dilutions (10-100%), cleared in xylene, and embedded in paraffin wax (melting point 60°C) under vacuum. Sections were cut at 7 wm and stained with Er- lich’s haematoxylin and eosin. Water samples were analyzed by the Institute of Natural Resources, University of the South Pacific. In general, methods for chemical analysis of water samples were those described in Standard Methods for the Examination of Water and Wastewater (AMERICAN PUBLIC HEALTH ASSOCIA- TION, 1981). TAXONOMY Acochlidium fijiensis Haynes & Kenchington, sp. nov. (Figures 1-6) Type locality: Nasekawa River, Vanua Levu, Fiji. Col- lection site at 16°40'S, 179°16’E. Type specimens: The holotype (LACM 2457) and 2 paratypes (LACM 2458) have been deposited in the Los A. Haynes & W. Kenchington, 1991 Figure 1 Photograph of a live Acochlidium fujiensis. The irregular pattern of white patches over the hump and foot is caused by spicules. Page 167 0-5 mm Figure 3 Penis gland of Acochlidium fijiensis showing: a, outer row of hooks; b, inner row of hooks; c, 6 small spines on the edge of the vas deferens opening. Angeles County Museum of Natural History. Ten para- type specimens of Acochlidium fijiensis have been deposited in the Naturhistorisches Museum Wien, Inventory Num- ber 84.901, and 7 paratypes, a radula, a penis permanently mounted in glycerine and slides of sectioned gonads are held in the Biology Department, School of Pure and Ap- plied Sciences, University of the South Pacific, Suva. The dissected specimens were collected in January 1988; ho- lotype, paratypes, and sectioned specimens were collected in July 1989. All type specimens were collected by A. Haynes. Size, abundance and maturity: Table 1 indicates the relative abundance and size of specimens of Acochlidium ane ue Fig. 2 Figure 2A. Ventral view of a row of radula teeth of Acochlidium fijiensis. B. Side view of median tooth showing fine serrations. Page 168 The Veliger, Vol. 34, No. 2 Figure 4 Coronal (horizontal longitudinal) section of the visceral hump of Acochlidium fijiensis stained with haematoxylin and eosin showing the extensive distribution of ovotestis acini (A) embedded in diverticula of the digestive gland (G). Scale bar = 0.1 mm. fijiensis collected from the Nasekawa River on five occa- sions from October 1983 to July 1989. Acochlidium fijiensis was most abundant in October 1983 and July 1989, and individuals were also largest in July 1989 when their body hump was enlarged because they were reproductively ma- ture. Histological sections of A. fijiensis specimens col- lected from the Nasekawa River in January 1988 and from the Lami River in November—December 1988 showed undeveloped gonadal tissue. Sections of specimens collected in July 1989 contained mature gonads (Figures 4, 5). This suggests that A. fijiensis has a well-defined breeding season (July-August, or perhaps longer during the cool, dry sea- son) and that, after breeding, either the gonads disintegrate or each individual breeds only once in its lifetime. In the mature individuals that had been prepared for histology, abundant yolk granules and sperm were noted, but very few oocytes could be seen. Presumably these specimens had already spawned. Habitat: Specimens of Acochlidium fijiensis were found on the underside of stones and rocks in shallow water, 60- 140 mm deep, near the water’s edge in both the Nasekawa and Lami rivers. When A. fijiensis were kept in the lab- oratory, they always moved to the underside of the stones. At the site in the Nasekawa River, the water level rose as much as 400 mm at high tide when heavy rain had been falling. However, when this occurred, there was little difference in the conductivity (or total ions) of the water at high and low tides (Table 2); therefore, the rise in water level is due to a back up of river water and not to inflowing seawater. The chemical content of the water was similar at each sampling time and at high and low tides (Table 2). The water temperature was 29°C in October 1983 when Aco- chlidium fijiensis was abundant but at other times when the site was visited the temperature was 25-26°C (Table 2). General Description Diagnosis: Length of animal up to 19 mm, foot longer than visceral hump, which is rounded at the posterior (except when eggs have been shed, when the posterior may be ragged and pointed). Color cream-yellow, with wide => Figure 5 Histological sections through the ovotestis of Acochlidium fijiensis stained with haematoxylin and eosin. A. See abundant spermatozoa (S) and yolk granules (Y). B. See spermatozoa, yolk granules and a possible oocyte (O). Scale bar = 50 um. Page 170 0.2mm 0.2mm Figure 6 Acochlidium fiyiensis. A. Developing eggs embedded in a jelly mass. B. Developing veligers, one still inside the egg membrane. C. Veliger larva swimming, after escaping from the egg membrane. brown stripes across the dorsal side. Rhinophores (3.5 mm live; 1.8 mm preserved) longer than the anterior pair of tentacles (1.6 mm live; 0.8 mm preserved). Spicules present on visceral hump and foot (Figure 1). Radula: Asymmetrical with formula 50 x (1:1-2-). Left marginal plate lacking and rachidian (median) tooth finely serrated (Figure 2A, B). Hermaphrodite: The penial armature consisting of a double row of long, curved hooks that form a border that almost surrounds the penial gland. A line of 6 small spines borders one side of the vas deferens opening (Figure 3). Reproduction and development: Acochlidium fijiensis is a hermaphrodite. This conclusion is based on an observed spawning followed by dissection revealing a well-devel- Table 1 The abundance and size of Acochlidium fijiensis collected from the Nasekawa River at different times. Duration of Number collection Date found (hr) Size (mm) 22 October 1983 16 1 not measured 7 August 1984 1 0.5 15 18-19 October 1985 12 6 6-11 19-20 January 1988 20 6 2-12 17 July 1989 30 2 10-19 The Veliger, Vol. 34, No. 2 Table 2 Physical and chemical parameters at the collecting site of Acochlidium fijiensis in the Nasekawa River. 22 October 1985 22 January 1988 Low tide High tide Low tide High tide Temperature (°C) 26 25 25 25 Water depth (mm) 60-140 460-600 60-140 60-160 Water speed (cm-s~') 0-30 0-10 0-30 0-30 pH 6.8 6.7 7.4 7.4 Conductivity (us-cm™'!) iD) 100.7 102.6 102.6 Total nitrogen (mg-L“") 8.2 7.1 25) 2.5 Total phosphorus (ug L“') 62.0 74.0 21.3 21.3 Ca (mg L“') 7.8 8.2 9.2 9.2 Mg (mg L"') 2)9) 5.6 4.1 4.1 Na (mg L"') 4.4 4.8 6.6 6.6 K (mg L") 0.26 0.29 0.85 0.85 oped penis. Also, sections of gonads (Figures 4, 5) show typical ovotestis composed of numerous acini, which are extensively distributed throughout the visceral hump where they are embedded amongst the diverticula of the digestive gland. In the specimens examined, acini were dominated by spermatozoa, spermatids, and associated generative tis- sue. Although yolk material was abundant, few oocytes were seen. The spawning occurred in a 15-mm-long specimen that had been collected on 7 August 1984 and transferred to an aquarium. Thirteen days after capture it laid eggs, and three days later it died. The jelly mass was attached to two separate stones: one mass contained 31 eggs and the other 25 eggs (Figure 6A). The yellow eggs were embedded in clear jelly. After 10 days veligers were observed moving within the jelly (Figure 6B). After a further 12 days some of the veligers had escaped from the jelly mass and were swimming freely (Figure 6C). No veligers survived more than two days after leaving the jelly mass. Discussion A comparison of live Acochlidium fijiensis with other live Acochlidium species is not possible as no descriptions of the latter are available. Preserved specimens of A. fi- jvensis were similar in appearance to those described by Wawra for A. sutterx and A. bayerfehlmanni. The radula of A. fijiensis was asymmetrical, as were those of A. sutteri (WAWRA, 1979) and A. bayerfehlmanni (WAWRA, 1980). In the case of A. fijiensis, the number of rows of teeth was 50 compared with 52-56 for other Acochlidium spp. except A. weberi, which had 93-103 (WAwRA, 1979). The ra- chidian teeth appeared to be comparatively narrower (110 um compared with 200 um in A. amboinense and A. sutteri and 210-230 um in A. bayerfehlmannz) and stouter, al- A. Haynes & W. Kenchington, 1991 though the laterals were approximately the same length (110-150 wm) (Wawra, 1979, 1980) (Figure 2). The male genital system of Acochlidium fijiensis was also similar to that of A. sutteri and A. bayerfehlmanni, with the male opening at the base of the right rhinophore (WAw- RA, 1979, 1980). The armature on the penial gland ap- peared to be more similar to that of A. bayerfehlmanni than A. suttert. However, the hooks in a double row nearly surrounding the penial gland in A. fijiensis were long and curved and the 6 small sharp spines were in a row on one side of the penis opening (Figure 3). In A. bayerfehlmanni the hooks are smaller and straighter and are not so exten- sive. The general anatomy of Acochlidium fijiensis more closely resembled that of A. bayerfehlmanni than A. sutter: but the penial armature was distinctly different from both. Live A. fijiensis were smaller (19 mm long) than A. bayerfehl- manni (25 mm long) (WAwRA, 1980). However, because such characteristics as the presence or absence of spicules and the comparative length of rhinophores and anterior tentacles have not previously been recorded, it is impossible to use them for comparisons within the genus Acochlidium. ACKNOWLEDGMENTS We thank the Research Committee of the University of the South Pacific for financial assistance (Grant No. 0701- Page 171 0063) and Jean Maybin, Gillianne Brodie, Valerie James, and the people from Vunivesi village near the site who helped to collect specimens in the Nasekawa River and Bernadette Holthuis who provided specimens of A. fijiensis from the Lami River. LITERATURE CITED AMERICAN PUBLIC HEALTH ASSOCIATION. 1981. Standard Methods for the Examination of Water and Waste Water. 15th ed. American Public Health Association, American Water Works Association, Water Pollution Control Fed- eration, Washington, D.C. Haynes, A. 1988. The gastropods in the streams and rivers of five Fiji islands: Vanua Levu, Ovalau, Gau, Kadavu and Taveuni. The Veliger 30(4):377-383. RANKIN, J. 1979. A freshwater shell-less mollusc from the Caribbean: structure, biotics, and contribution to a new un- derstanding of the Acochlidioidea. Life Sciences Contribu- tions, Royal Ontario Museum 116:1-123. Wawra, E. 1974. The rediscovery of Strubellia paradox (Stru- bell) (Gastropoda, Euthyneura, Acochlidiacea) on the So- lomon Islands. The Veliger 17(1):8-10. Wawra, E. 1979. Acochlidium sutteri nov. spec. (Gastropoda, Opisthobranchia, Acochlidiacea) von Sumba, Indonesien. Annalen des Naturhistorischen Museums in Wien 82:595- 604. Wawra, E. 1980. Acochlidium bayerfehlmanni spec. nov. (Gas- tropoda: Opisthobranchia: Acochlidiacea) from Palau Is- lands. The Veliger 22(3):215-218. The Veliger 34(2):172-194 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Taxonomy of Japanese Species of the Genera Mopalia and Plaxiphora (Polyplacophora: Mopaliidae) HIROSHI SAITO ano TAKASHI OKUTANI Tokyo University of Fisheries, 4-5-7, Konan, Minato-ku, Tokyo 108, Japan Abstract. Four species of the chiton genus Mopalia and one species of the genus Plaxiphora are recognized in the intertidal and sublittoral zones of Japan: M. middendorffu (Schrenck, 1861), M. retifera Thiele, 1909, M. schrencki Thiele, 1909, M. seta Yakovleva, 1952, and Plaxiphora integra (Is. Taki, 1954). Mopalia hirsuta Is. Taki, 1938, is a synonym of M. middendorffii. The Japanese records of M. wosnessenskit (Middendorff, 1847a) may be attributable to misidentification; therefore, no West Pacific species of the genus Mopalia is confirmed to occur in common with the East Pacific. The transfer of Mopalia integra into Plaxiphora is affirmed. Plaxiphora integra is newly recorded from the Ogasawara Islands as a southern extension of distribution. The shells, girdle elements, radula, and digestive tract of each species are described and illustrated. INTRODUCTION The genus Mopalia is endemic to the North Pacific. Eighteen species occur along the west coast of North Amer- ica (LYONS, 1988), and several species are known from the northwestern Pacific. In Japan and adjacent waters, Is. TAKI (1962) and Iw. Taki (1964) listed seven species: ““Mopalia (Mopalia) wosnessenski (Middendorff, 1847), M. (M.) middendorffui (Schrenck, 1867), M. (M.) retifera Thiele, 1909, M. (M.) schrenckii Thiele, 1909, M. (M.) hirsuta Is. Taki, 1938, M. (M.) seta Yakovleva, 1952, and M. (Hachi- jomopalia) integra Is. Taki, 1954.” The descriptions on specimens from the Japanese coast were confined to only three species, M. retifera, M. hirsuta, and M. integra. The present paper describes the morphological characters of each species and reports on their distribution along the Japanese coast. The systematic position of Mopalia (Hachi- jomopalia) integra, which was previously transferred by Kaas & VAN BELLE (1980) from Mopalia into Plaxiphora, is confirmed by examination of the new material collected from both the Hachijo and Ogasawara islands. Family MOPALIIDAE Dall, 1889 Genus Mopalia Gray, 1847a Type species: Chiton hinds (Sowerby MS) Reeve, 1847 (S.D. by Gray, 1847b). Mopalia schrencki Thiele, 1909 (Figures 1-15, 74, 78) Type locality: 4-5 miles (6-8 km) west of Schamow Inlet, Terpeniya Bay, southeast Sakhalin, 15-20 fathoms (27- 36 m). Mopalia schrencki THIELE, 1909:30, pl. 4, figs. 4-10; Is. TaK1, 1955:203, fig. 3; KAAS & VAN BELLE, 1980:117 (name only); SIRENKO, 1985:356-357 (distribution). Mopalia schrencki: YAKOVLEVA, 1952:78, fig. 33, frontis. fig. 3, pl. 5, fig. 1; KLIMOVA & SIRENKO, 1976:79, fig. 185; SIRENKO, 1976:90-91 (distribution). Mopalia (Mopalia) schrencku: Is. TAK, 1962:33 (name only); Iw. TAKI, 1964:410 (name only). Material examined: See Table 1. Description: Animal small to medium in size, attaining 30 mm in body length, oblong in outline (Figures 1, 74). Valves: Head valve (Figure 2) semicircular, apex mod- erately elevated, anterior slope straight to slightly convex, posterior margin widely V-shaped; tegmental surface with eight radiating rows of tubercular ribs, arranged in cor- respondence with slits; posterior edge dentate by elongate tubercles; interspaces between ribs with obliquely inter- secting fine riblets, and points of intersecting becoming granular; interior smooth and shiny; insertion plates long, squarish, nearly smooth; slits deep, usually eight in num- H. Saito & T. Okutani, 1991 ber, bounded on each side by conspicuous upturned edge of insertion plate; slit rays slightly grooved with minute slitlike pores. Intermediate valves (Figure 3) wide, valve V widest, roughly rectangular in shape, but anterolateral corners obtusely angular, posterior margin nearly straight with slightly projected beak; dorsal ridge elevated, subcarinate to fairly carinate; side slopes nearly straight; lateral areas not elevated but clearly separated from central area by diagonal rib similar to ribs of head valve, bordered by elongate tubercles; central area with slightly inwardly curving longitudinal riblets, finer and sometimes anasto- mosing at jugal area, many threads between riblets; sculp- ture of lateral areas similar to that of interspace between ribs of head valve; interior smooth with low callus anterior to slightly grooved slit rays; sutural laminae wide with roundish anterior edge, separated by fairly wide sinus; insertion plates short, slightly projecting laterally beyond narrow eaves; sutural laminae and insertion plates with upturned edge at both sides of slit; one slit per side. Tail valve (Figure 4) small, depressed, roughly trape- zoid in shape, anterior margin gently convex, posterior end with shallow sinus; mucro slightly raised, situated near posterior end; anterior slope nearly straight; central area sculptured like that of intermediate valves; posterior area slightly raised, separated from central area by tubercular diagonal rib, then steeply descended posteriorly, with gran- ular to nearly smooth surface; interior considerably rough- ened and thickened along posterior edge; sutural laminae broadly extended anteriorly, rounded at both corners, sep- arated by V-shaped sinus; insertion plates short, obtuse at edge, roughened on lateral surface; one slit per side; slit rays inconspicuous, perceptible as series of minute pores. Girdle: Girdle narrow, setose, slightly encroaching at su- tures; perinotum covered by setae of various sizes and minute spicules; largest setae (Figure 7) situated on side of sutures and around terminal valves, others intermingle with smaller ones; each seta with many long threadlike bristles extending from dorsal groove; bristles flexible, gradually tapering toward distal end, tipped with minute spicule (Figure 7a) that is slender, hyaline, sharply pointed at tip, 20-25 wm in length and attached only at base; similar solitary bristles (Figure 6) dispersed or present in small tufts among densely set spicules, closely implanted on pe- riphery; spicules on perinotum (Figure 8) minute, smooth, pointed at tip, brownish orange in color, 40-70 wm in length; marginal spicules (Figure 10) long, hyaline, obliquely striated, 110-135 um in length; spicules on hy- ponotum (Figure 9) larger than those of perinotum, hy- aline, striated along nearly entire length, 60-110 um in length; spicules on pallial fold (Figure 11) slightly smaller, 45-70 um in length and sparsely set. Radula (Figures 12, 13, 78): Central tooth roughly rect- angular with distal entire cutting edge, moderately swollen at middle, both sides of basal portion constricted and thick- Page 173 ened posteriorly, well concave at posterior surface, prop plate with rather pointed end; centro-lateral with small cusplike projection at outer lateral corner of dorsal edge, posterior portion strongly extended and reflexed laterally forming an auricular projection, propped by narrow basal plate extended laterally; major lateral with strong triden- tate cusp sharply pointed at tip, middle denticle largest, outer lateral one smallest, shaft stout, thick, strongly keeled dorsally, dilated ventrally; inner small lateral solid, much elevated, narrowly extended anteriorly and dilated later- ally at bottom; outer small lateral roughly rhomboid in shape, sinuated at both lateral surfaces, slightly extended anteriorly and posteriorly at bottom; major uncinus (Fig- ure 13) slender, spoon-shaped, evenly arched posteriorly, slightly undulated twice laterally with rather short cusp; inner and middle marginals roughly rhomboid in shape, thick and platelike; outer marginal rather narrow, thin and platelike. Digestive tract (Figure 5): Stomach pouchlike, but rather narrow, blind end situated at right side of visceral mass; anterior intestine originates from left side of stomach, dor- sally runs posteriorly to right with U-shaped loop; intes- tinal valve recurves back and connects with posterior in- testine; posterior intestine runs anteriorly within anterior intestine, descends between beginning of anterior intestine and intestinal valve, then turns to right and runs poste- riorly, revolves one and a half times ventrally and leads back to long rectum. Gills, gonopore, and nephridiopore: Gills merobran- chial and abanal, usually extending from under valve IV to under posterior margin of valve VII, with number of gills increasing with growth (Figure 14); gonopore typi- cally located between posterior second and third gills, and nephridiopore situated one ctenidium behind the gonopore (between two posteriormost gills). Heart: Heart with one pair of auriculo-ventricular ostia. Coloration: Preserved valves varying from olivaceous green or dark yellow to orange, banded with white at around jugal area and maculated with brown; interior of valves white; perinotum uniformly brownish orange to light brown; hyponotum uniformly light brown. Distribution: Hokkaido, southern Kuril Islands, Sakha- lin, and the Sea of Japan coast of the USSR (Figure 15), on underside of stones in littoral and sublittoral zones. The deepest record is 50 m, off Shikotan Island (SIRENKO, 1976). Remarks: This species can be sufficiently distinguished from the related species Mopalia seta Yakovleva, 1952, by its having shorter insertion plates, a shallow but distinct posterior sinus of the tail valve, finer bristles, and a smaller number of gills (Figure 14). The costate valve sculpture and threadlike bristles are reminiscent of M. cirrata Berry, 1919, but the latter species differs in its coarser sculpture, Page 174 The Veliger, Vol. 34, No. 2 5mm 12, 13 500ym 17 6,8-11 7a 100pm Explanation of Figures 1 to 13 oo ry 10 cos Figures 1-13. Mopalia schrencki Thiele, 1909. Figures 1-4: body length 19.5 mm, from Rausu. Figures 5, 7, 7a: body length 31.2 mm, from Saruru. Figures 6, 8-13: body length 23.4 mm, from Akkeshi. H. Saito & T. Okutani, 1991 30 C) r ) @ rn e = 75) @ @ @ @ S ® ) ® r) eo @ ® C) ro) @ 8e ee = e e fo) ® 20 (oe) a @ é «oo 00 fo) fo) z= (ome) 15 ° fo) 10 oh EE ee 0 10 20 30 40 50 60 Body length (mm) Figure 14 Relationship between body length and number of gills of two Mopalia species. Open circles, M. schrencki (n = 16); solid circles, M. seta (n = 29). deep posterior sinus of the tail valve, and scalelike spicules of the perinotum. Mopalia seta Yakovleva, 1952 (Figures 14, 16-30, 75, 80) Type locality: Southern part of Japan Sea (by Yakovleva). Mopalia seta YAKOVLEVA, 1952:77, fig. 32, frontis. fig. 7, pl. 4, fig. 3; SIRENKO, 1976:91 (distribution); SIRENKO, 1985: 356 (distribution); KAAS & VAN BELLE, 1980:118 (name only). Mopalia wosnessenski: Is. TAKI, 1955:204 (distribution) (non MIDDENDORFF, 1847a). Mopalia (Mopalia) wosnessenski: Is. TAKI, 1962:32 (name only); Iw. TAKI, 1964:411 (name only); ISHIKAWA, 1966: 96 (in part) (all non MIDDENDORFF, 1847a). Mopalia (Mopalia) seta: Is. TAKI, 1962:33 (name only); Iw. TAKI, 1964:411 (name only). Figure 1. Dorsal view of animal. Figure 2. Head valve, dorsal and anterior views. Figure 3. Valve IV, dorsal and anterior views. Figure 4. Tail valve, dorsal, ventral, and lateral views. Figure 5. Digestive tract, dorsal view. Figure 6. Isolated bristle. Figure 7. Seta, middle portion. Figure 7a. Bristle of seta, distal end with spicule. Figure 8. Spicules on perinotum. Figure 9. Spicule on hyponotum. Figure 10. Marginal spicules. Figure 11. Spicules on pallial fold. Figure 12. Radula, half row. Figure 13. Major uncinus, posterior and lateral views. 50°N 40° PACIFIC OBA OF OCEAN JAPAN Figure 15 Distribution of Mopalia schrenckt. Localities indicated as follows: numbers, this study (see Table 1); star, type locality; solid circles, SIRENKO (1976); triangles, SIRENKO (1985). Material examined: See Table 2. Description: Animal medium to large in size, attaining 55 mm in body length, elliptical in outline (Figures 16, iS): Valves: Head valve (Figure 17) semicircular, apex fairly elevated, anterior slope straight to slightly convex; teg- mental surface with eight radiating rows of tubercular ribs arranged in correspondence with slits; posterior edge den- tate by smaller tubercles, but hardly raised; interspace Abbreviations: a, anus; ai, anterior intestine; iv, intestinal valve; pi, posterior intestine; s, stomach. Page 176 The Veliger, Vol. 34, No. 2 Table 1 Data of specimens of Mopalia schrencki used in this study. Number of Locality* Collecting depth (m) individuals Body length (mm) Date collected Collector Pacific Coast 1. Akkeshi intertidal 3 21.3-23.8 10-13 July 1983 Y. Kuwahara 2. Higashi-shizunai 1 1 27.0 22 Aug. 1986 H. Saito Okhotsk Sea 3. Kitami-esashi 0.5-2 5 12.6-16.1 11 Aug. 1987 H. Saito 4. Saruru 1 1 31.2 18 Aug. 1986 H. Saito Saruru 0.5 1 22.0 10 Aug. 1987 H. Saito 5. Saroma 8 1 ca. 23 5 June 1987 H. Hoshikawa 6. Rausu 5 2 18.0, ca. 20 29 July 1988 R. Inoue Rausu 4 2 ca. 15, 19.5 — I. Soyama Japan Sea 7. De Castries Bay — 1 16.0 22 Aug. 1982 B. Sirenko 8. Wakkanai unknown** 1 11.4 12 Aug. 1987 H. Saito 9. Oshoro 8-9 1 16.8 17 Aug. 1987 H. Saito 10. Vostok Bay =?) 2 15.4, 21.0 1 Sep. 1980 B. Sirenko * Locality number corresponds to that in Figure 15. ** Incidentally caught by gill net operated in depth probably shallower than 30 m. between ribs with obliquely intersecting riblets; interior smooth, shiny; insertion plates well developed, long, squar- ish, nearly smooth; slits deep, usually eight in number, bounded on each side by conspicuous upturned edge of insertion plates; slit rays not grooved, appearing as whitish lines with series of minute slitlike pores. Intermediate valves (Figure 19) wide, valve V widest, anterior margin roughly rounded and posterior margin slightly concave, only slightly beaked, rather depressed and weakly carinate at dorsal ridge, with slightly convex side slopes; lateral areas not elevated but clearly separated from central area by diagonal rib similar to ribs of head valve, and posterior margin bordered by elongate tubercles; cen- tral area with longitudinal riblets, which are sometimes bifurcated near anterior margin, finer and coalescent at around jugal area, inner surface of these riblets buttressed by numerous, fine, clawlike, tranverse riblets; sculpture of lateral areas similar to that between ribs of head valve, but riblets often arranged in herringbone or zigzag pattern; interior smooth, shiny with transverse callus extending from center to near slits; sutural laminae wide with round- ish anterior edge, separated by widely V-shaped sinus; insertion plates long, strongly projecting laterally beyond narrow eaves; insertion plates and sutural laminae with upturned edge on both sides of slit; one slit per side; slit rays with series of minute pores and not grooved. Tail valve (Figure 18) small, depressed, roughly oval in shape, rounded on both corners of anterior margin, hardly incised at posterior margin; mucro not raised and situated at about posterior third; anterior slope slightly convex, posterior slope behind mucro slightly concave; cen- tral area sculptured like that of intermediate valves; pos- terior area granular around mucro; interior thickened along posterior edge; sutural laminae broadly extended anteri- orly, anterior edge obliquely truncated, separated by wide- ly V-shaped sinus; insertion plates short, obtuse at edge, roughened on lateral surface; one slit per side; slit rays with several minute slitlike pores and not grooved. Girdle: Girdle wide, setose, moderately encroaching at sutures; perinotum densely covered by setae of various lengths and minute spicules; largest setae (Figure 21) sit- uated on side of sutures and around terminal valves, others gradually becoming smaller toward periphery and inter- mingled with smaller ones on entire surface; each seta with many long, fine, curved bristles, thickest at middle, taper- ing toward both ends, tipped at distal end with minute spicules (Figure 21a) that are slender, hyaline, slightly curved, 30-70 um in length, embedded in bristle in prox- imal half; similar bristles (Figure 22) dispersed as solitary ones or in small tufts among densely set spicules closely implanted on periphery; spicules on perinotum (Figure 24) minute, sharply pointed at tip, brownish orange in color, 55-70 um in length; marginal spicules (Figure 25) long, hyaline, obliquely striated or nearly smooth, 145- 185 wm in length; spicules on hyponotum (Figure 23) longer than those of perinotum, hyaline, striated, 95-125 um in length; spicules on pallial fold (Figure 26) slightly more slender than other hyponotal spicules and sparsely set. Radula (Figures 27, 28, 80): Central tooth roughly rect- angular with distal cutting edge, slightly swollen at middle, constricted laterally and thickened posteriorly at bottom, concave on posterior surface, prop plate thick and rounded anteriorly; centro-lateral with small cusplike projection at outer lateral corner of dorsal edge, posterior portion strong- H. Saito & T. Okutani, 1991 Page 177 Pee A OT BEST aag ~9P Fy Ty) 1144 ¥. A, (st ie yt Explanation of Figures 16 to 20 Figures 16-20. Mopalia seta Yakovleva, 1952. Figures 16-19. body length 29.0 mm, from Muroran. Figure 20. body length 7.6 mm, from Hamamasu. Figure 16. Dorsal view of grown animal. Figure 17. Head valve, dorsal and anterior views. Figure 18. Tail valve, dorsal, ventral, and lateral views Figure 19. Valve IV, anterior and dorsal views. Figure 20. Dorsal view of young animal. Page 178 The Veliger, Vol. 34, No. 2 22-26 Explanation of Figures 21 to 29 Figures 21-29. Mopalia seta Yakovleva, 1952. Figure 21, 21a. body length ca. 22 mm, from Otamoi. Figures 22- 26. body length 43.6 mm, from Muroran. Figures 27, 28. body length 29.0 mm, from Muroran. Figure 29. body length ca. 37 mm, from Hamamasu. Figure 21. Seta, middle portion. Figure 21a. Bristle of seta, distal end with spicule. Figure 22. Isolated bristles. Figure 23. Spicules on hyponotum. Figure 24. Spicules on perinotum. Figure 25. Marginal spicules. Figure 26. Spicules on pallial fold. Figure 27. Radula, half row. Figure 28. Major uncinus, posterior and lateral views. Figure 29. Digestive tract, dorsal view. See Figure 1-13 for abbreviations. ly extended and reflexed laterally forming auricular pro- jection, propped by basal plate with obtuse end; major lateral with strong and tridentate cusp, denticles sharply pointed at tip, middle denticle longest, outer lateral one smallest; shaft stout, thick, strongly keeled dorsally, dilated ventrally but concave at middle of outer lateral side; inner small lateral solid, much elevated, extended anteriorly at boticm, deeply concave at outer lateral surface; outer small lateral elevated, roughly sigmoid in shape, sinuated at both lateral surfaces, slightly extended anteriorly and posteri- orly at bottom; major uncinus (Figure 28) slender spoon- shaped, gently curved posteriorly but slightly angular at middle; inner marginal thick, platelike, roughly rhomboid in shape, narrowing anteriorly and sinuated at inner side; middle marginal roughly rhomboid-shaped and outer mar- ginal squarish, thin and platelike. Digestive tract (Figure 29): Stomach pouchlike, blind end situated at right side of visceral mass; anterior intestine originates from left side of stomach, dorsally runs poste- riorly to right with U-shaped loop; intestinal valve situated at middle of left side of intestinal mass, turns back and connects with posterior intestine; posterior intestine runs along inside of anterior intestine, turns to right, revolves H. Saito & T. Okutani, 1991 Page 179 140° L5O“)s 50°N OKHOTSK SEA 40° PACHENE SEA OF OCEAN JAPAN Figure 30 Distribution of Mopalia seta. Localities indicated as follows: num- bers, this study (see Table 2); solid circles, SIRENKO (1976); triangles, SIRENKO (1985). one and a half times ventrally, ascends and passes over intestinal valve, leads back to rectum. Gill, gonopore, and nephridiopore: Gills merobranchial and abanal, usually extending from under posterior margin of valve III to that of valve VII, with number of gills gradually increasing with growth in adult stage (Figure 14); gonopore typically located between posterior second and third gills, and nephridiopore situated one ctenidium behind gonopore (between two posteriormost gills). Heart: Heart with one pair of auriculo-ventricular ostia. Coloration: Preserved valves olivaceous green maculated and banded with brown and blue-green; interior of valves white; perinotum uniformly light brown or yellowish brown; hyponotum light brown. Distribution: Hokkaido, southern part of Kuril Islands, Sakhalin, and the Sea of Japan coast of the USSR (Figure 30), on rocks covered with sea weeds or on the underside of large stones in the littoral and sublittoral zones. The deepest record is 51 m, off Shikotan Island (KLIMOVA & SIRENKO, 1976). Remarks: This species resembles Mopalia ciliata (Sowerby, 1840), M. swanu Carpenter, 1864, M. schrencki Thiele, 1909, M. phorminx Berry, 1919, and M. spectabilis G. I. McT. Cowan & I. McT. Cowan, 1977, in the possession of longitudinally costate sculpture of the valves. But, they are distinguishable from M. seta by the following points. Table 2 Data of specimens of Mopalia seta used in this study. Number of Locality* Collecting depth (m) individuals Body length (mm) Date collected Collector Pacific Coast 1. Nosappu intertidal 1 ca. 55 30 July 1988 S. Matsumura Nosappu intertidal 1 47.5 12 June 1987 S. Murakami 2. Akkeshi intertidal 3 40.2-55.8 13 June 1987 S. Murakami Akkeshi intertidal 19 20.0-48.4 7-13 July 1983 Y. Kuwahara Akkeshi intertidal 3 34.0-38.5 18 Aug. 1982 H. Hoshikawa Akkeshi 1 1 14.5 8 Aug. 1987 H. Saito 3. Hiroo intertidal 1 44.3 10 Aug. 1984 Y. Kuwahara 4. Muroran intertidal-1 11 16.9-43.6 16 Aug. 1987 H. Saito Muroran intertidal 3 29.5-35.5 10 Aug. 1983 Y. Kuwahara Muroran intertidal 1 17.0 25 May 1975 Y. Kuwahara Okhotsk Sea 5. Notoro unknown** 1 ca. 20 24 July 1986 H. Hoshikawa Japan Sea 6. Hamamasu 0.5-3 3 7.6-ca. 37 17 Aug. 1986 H. Saito 7. Otamoi 2 1 ca. 22 16 Aug. 1986 H. Saito 8. Oshoro intertidal—3 3 17.3-20.1 18 Aug. 1987 H. Saito 9. Vostok Bay 1-2 2 25.5, 35.6 1 Sep. 1980 B. Sirenko * Locality number corresponds to that in Figure 30. ** Incidentally caught by trawl net for Yezo scallop. Page 180 (1) M. ciliata, M. swani and M. spectabilis have a shorter tail valve with a wide posterior sinus and smoother sculp- ture of tegmentum. (2) M. ciliata has bristles with large and whitish spicules that are more similar to those of M. retifera than M. seta, the spicules attaining 300 wm in a specimen of body length 29 mm instead of 30-70 um in almost the same sized specimen of M. seta. (3) M. swaniz has sparse and short setae. (4) M. spectabilis has brilliant color, its red and turquoise-blue coloration of the valves is never present in M. seta, and it has longer spicules of the bristles, the spicules attaining 150 wm in a specimen of body length 34 mm. (5) M. schrencki has shorter insertion plates and finer bristles of the setae with smaller distal spicules and fewer gills (Figure 14). (6) M. phorminx has a secondary series of granules between the primary series on the head valve and between the diagonal rib and pos- terior margin of the intermediate valves, and shorter in- sertion plates. The tegmental sculpture changes with growth. The sculpture of the central area is chiefly simple longitudinal riblets in an individual of 7.6 mm valve length (Figure 20). In older animals the sculpture becomes reticulate and the longitudinal riblets near the anterior margin are often bifurcated. Earlier Japanese authors (e.g., Is. TAKI, 1962; Iw. TaKI, 1964; ISHIKAWA, 1966) listed Mopalia wosnessensku (Mid- dendorff, 1847a) as a member of the Japanese mopaliid fauna, but no detailed description based on specimens from Japan has been given by anyone. Mopalia wosnessensku has costate sculpture of the tegmentum, a shorter tail valve with a wide posterior sinus, and a wide girdle with nu- merous setae, which are clearly shown in the illustration by MIDDENDORFF (1847b). These features recall those of M. ciliata, so that the taxonomic status of M. wosnessenskit is confusing. DALL (1879) regarded it as a distinct species, but later (1921), as a subspecies of M. ciliata. ABBOTT (1974) and Kaas & VAN BELLE (1980) also regarded it as a subspecies of M. ciliata, while PILSBRY (1893) and LELoupP (1942) treated it as a variety of M. czlzata. In spite of considerable effort to confirm the occurrence of M. wos- nessensku or M. ciliata in Japanese waters, no specimen referable to this species has been found either on shore or in any museum or private collections, though M. retzera, M. schrencki and M. seta were commonly found. Judging from the similarity in general appearance between M. seta and the M. ciliata-wosnessensku complex, the Japanese rec- ords of the latter taxon may be attributable to a misiden- tification. Therefore, none of the West Pacific species of the genus Mopalia is confirmed to occur in common with those of the East Pacific. Mopalia middendorffu (Schrenck, 1861) (Figures 31-45, 73, 81) Type locality: De Castries Bay, Sea of Japan coast of the USSR. The Veliger, Vol. 34, No. 2 Chiton middendorffu SCHRENCK, 1861:89; SCHRENCK, 1862 (1861):408; SCHRENCK, 1867:278-281, pl. 12, figs. 1-8. Mopalia middendorffir: PILSBRY, 1893:301, pl. 62, figs. 88- 92; THIELE, 1909:30, pl. 3, figs. 53-60; SIRENKO, 1976: 91 (distribution); SIRENKO, 1985:357 (distribution); YAKOVLEVA, 1952:76-77, fig. 31, frontis. fig. 8, pl. 4, fig. 2. Mopalia hirsuta Is. TAKI, 1938:347-350, pl. 14, fig. 11, pl. 21, figs. 2, 4-6, pl. 23, figs. 12, 13; Is. Taki, 1955:203, fig. 2; Kaas & VAN BELLE, 1980:60 (name only). Mopalia middendorffi: Is. TAKI, 1955:203, fig. 1; KAAS & VAN BELLE, 1980:85 (name only). Mopalia (Mopalia) hirsuta: Is. TAKI, 1962:33 (name only); Iw. TAKI, 1964:410 (name only); ISHIKAWA, 1966:96 (distribution, as Azrusta). Mopalia (Mopalia) middendorffu: Is. Taki, 1962:33 (name only); Iw. TAKI, 1964:411 (name only). Material examined: See Table 3. Description: Animal small to medium in size, attaining 30 mm in body length, oblong in outline (Figures 31, 73). Valves: Head valve (Figure 32) thin, semicircular with moderately peaked apex, anterior slope nearly straight; tegmental surface with eight nearly smooth radiating ribs that correspond with slits, interspace between ribs finely pitted, appearing finely reticulate; posterior margin nearly smooth, slightly raised; interior smooth, shiny without cal- lus, bordered by folded tegmentum that is conspicuous and triangular at top; insertion plates long, squarish, nearly smooth; slits deep, usually eight in number and bounded on each side by conspicuous tile-like upturned edge of insertion plates; slit rays appear as white lines with series of minute slitlike pores and not grooved. Intermediate valves (Figure 34) wide, valve V widest, rectangular in shape, anterior margin gently convex, pos- terior margin almost straight, slightly beaked and smooth, much elevated and subcarinate at dorsal ridge with nearly straight side slopes; lateral areas much elevated, diagonal ribs hardly separable; central area finely reticulate, ap- pearing as pitted flat surface rather than granularly ribbed; meshes or pits of reticulum moderately deep, squarish, almost equal in size except in jugal area; lateral areas have reticulation similar to that of head valve, often obsolete; posterior margin nearly smooth; interior smooth with cal- lus extending from midline to near slit; sutural laminae thin, wide, regularly arched at anterior edge, separated by widely V-shaped sinus; insertion plates thin, short but slightly projecting laterally beyond narrow and spongy eaves; insertion plates and sutural laminae with upturned edge on both sides of slits; one slit per side; slit rays appear as series of minute pores and not grooved. Tail valve (Figure 33) small, roughly oval in shape, anterior margin gently convex, shallowly sinuated at pos- terior end; mucro raised, situated near posterior end; an- terior slope slightly concave and posterior slope steeply descending to posterior sinus; central area sculptured like that of intermediate valves; posterior area raised and sculp- tured like that of lateral areas of intermediate valves; in- H. Saito & T. Okutani, 1991 Page 181 Ores COV oy bg Oe ew Explanation of Figures 31 to 34 Figures 31-34. Mopalia middendorffu (Schrenck, 1861). Valve length 16.9 mm, from Oshoro. Figure 31. Dorsal view of animal. Figure 32. Head valve, dorsal and anterior views. Figure 33. Tail valve, dorsal, ventral, and lateral views. Figure 34. Valve IV, anterior and dorsal views. terior thickened along posterior edge; sutural laminae broadly extended anteriorly, truncated but roundly pro- jecting at inner corner of anterior edge, separated by V-shaped sinus; insertion plates short, obtuse at edge, con- siderably roughened on lateral surface; one slit per side; slit rays with several slitlike pores and not grooved. Girdle: Girdle rather narrow, setose, slightly encroaching at sutures; perinotum covered by numerous setae of various lengths and minute spicules; largest setae (Figure 36) sit- uated on side of sutures and around terminal valves, sub- sequent ones gradually becoming finer and shorter toward periphery; each seta with several rather short, fine, nearly Page 182 /36 “38 The Veliger, Vol. 34, No. 2 36a ___ room 35, 37-40 Explanation of Figures 35 to 43 Figures 35-43. Mopalia middendorffi (Schrenck, 1861). Valve length 16.9 mm, from Oshoro. Figure 35. Isolated bristle. Figure 36. Seta, middle portion. Figure 36a. Bristle of seta, distal end with spicule. Figure 37. Spicules on perinotum. Figure 38. Spicules on pallial fold. Figure 39. Marginal spicule. Figure 40. Spicules on hyponotum. Figure 41. Radula, half row. Figure 42. Major uncinus, posterior and lateral views. Figure 43. Digestive tract, dorsal view. See Figures 1-13 for abbreviations. straight bristles with minute slender distal spicule (Figure 36a), 15-25 um in length; similar bristles (Figure 35) found singly, or in small tufts among densely set perinotal spicules, closely implanted on periphery; spicules on peri- notum (Figure 37) minute, sharply pointed at tip, usually striated at distal third, brownish orange in color, 50-90 um in length; marginal spicules (Figure 39) slender, hy- aline, strongly and obliquely striated, 95-125 um in length; spicules on hyponotum (Figure 40) somewhat larger than those of perinotum, finely striated or nearly smooth, light brown in color, 60-95 wm in length; spicules on pallial fold (Figure 38) minute, extremely slender, hyaline, 30- 45 um in length, ca. 4 um in diameter, intermingled with spicules of ordinary size, 30-40 um in length and 10-12 pm in diameter. Radula (Figures 41, 42, 81): Central tooth broad with distal cutting edge, both sides strongly constricted near top, swollen at middle, constricted again and thickened pos- teriorly at bottom, concave on posterior surface, prop plate with moderately sharp end; centro-lateral with cusplike projection at outer lateral corner of dorsal edge, posterior portion strongly extended and reflexed laterally, propped by basal plate with obtuse end; major lateral with triden- tate cusp, denticles of which are slender, sharply pointed at tip, with middle denticle longest and outer one smallest; shaft strongly keeled dorsally, dilated ventrally; inner small lateral solid, much elevated, extended anteriorly at bottom, deeply concave at outer lateral surface; outer small lateral elevated, roughly rhomboid-shaped, sinuated at both lat- eral surfaces, slightly extended anteriorly and posteriorly H. Saito & T. Okutani, 1991 Page 183 30 ® # 25 i) § E @@ = ® 20 ® @ a 0 10 20 30 Body length (mm) Figure 44 Relationship between body length and number of gills of Mopalia middendorffu (n = 6). at bottom; major uncinus (Figure 42) slender, gently curved posteriorly with slender footlike basal plate directed an- teriorly, shaft almost straight in posterior view; inner mar- ginal thick, platelike, narrowing anteriorly and sinuated at inner lateral side; middle marginal roughly rhomboid- shaped; outer marginal thin, platelike and squarish in shape. Digestive tract (Figure 43): Stomach pouchlike, blind end situated at right side of visceral mass, but not reaching dorsal surface; anterior intestine originates from left side of stomach, dorsally runs posteriorly with U-shaped loop; intestinal valve turns back and connects with posterior intestine; posterior intestine runs along inside of anterior intestine, descends between beginning of anterior intestine and intestinal valve, then turns to right, loops one and a half times ventrally and leads back to rectum. Gills, gonopore, and nephridiopore: Gills merobran- chial and abanal, usually extending from under middle or posterior end of valve III to that of valve VII, with number 140° 150°E 50°N OKHOTSK SEA 40° Figure 45 Distribution of Mopalia middendorffi. Localities indicated as fol- lows: numbers, this study (see Table 3); star, type locality; solid circles, SIRENKO (1976); triangle, SIRENKO (1985); open circle, type locality of Mopalia hirsuta by Is. TAKI (1938); square, ISHI- KAWA (1966). increasing with growth (Figure 44); gonopore typically located between posterior second and third gills, and ne- phridiopore situated one ctenidium behind the gonopore (between two posteriormost gills). Heart: Heart with one pair of auriculo-ventricular ostia. Coloration: Preserved valves reddish brown with broad whitish areas along jugal area, or whitish with brownish bands on central area, jugal area pinkish; interior of valves translucent and color of tegmentum faintly visible, peri- notum uniformly brownish orange; hyponotum same as perinotum except for whitish pallial fold. Table 3 Data of specimens of Mopalia middendorffu used in this study. Collecting Number of Locality* depth (m) individuals Pacific Coast 1. Ozuchi 12 1 Japan Sea 2. Oshoro 6-10 5 * Locality number corresponds to that in Figure 45. Body length (mm) 18.0 17 June 1983 11.0-28.1 Date collected Collector H. Hoshikawa 17-19 Aug. 1987 H. Saito Page 184 Distribution: Pacific coast of northern part of Honshu, northern part of Sea of Japan (Figure 45), on underside of stones in sublittoral zone. The shallowest recorded depth is 2 m in Vostok Bay (SIRENKO, 1976), and the deepest record is 60 m in Mutsu Bay (Is. Taki, 1938, as M. hirsuta). Remarks: Is. TAKI (1938) described Mopalia hirsuta based on a single small specimen (body length 9 mm) collected from Mutsu Bay. Mopalia hirsuta has elevated and sub- carinated valves with reticulate sculpture, characteristic long setae with fine straight bristles, and brownish red coloration. These features agree well with those of M. middendorffu. Although he considered it to be closely re- lated to M. middendorffu, Is. TAKI (1938) indicated the following morphological characters as sufficient to distin- guish the two species: (1) coarse sculpture of the tegmen- tum, (2) denticulated posterior margin of the valves, (3) acute divergence of the intermediate valves, (4) small cal- careous tip of bristles in the girdle, (5) minute strongly ridged scales on the perinotum, and (6) more elongate body. The first two characters are juvenile features; both the sculpture and the posterior margin of the valves become smooth with growth. Characters (3), (5), and (6) reflect intraspecific variation. Taki measured a 105° divergence of the intermediate valves of the type specimen of M. hirsuta compared with 115° in the type of M. middendorffu, while the present specimens exhibit a range of 100° to 114°. The striations of the perinotal spicules were illustrated ambig- uously by THIELE (1909) and those on the distal third of the spicules by YAKOVLEVA (1952). However, such stria- tions or ridges were usually observed on the distal third of spicules in the material we examined; striations along the entire length of the spicules, as illustrated by Thiele and Taki, were also observed. Character (4) was described neither in the original description nor in any subsequent redescription of M. middendorffu. The fact that authors did not mention the spicules could be due to their being overlooked or because damaged specimens were being stud- ied. Therefore, the above-mentioned characters are not significant to distinguish the species. Mopalia retifera Thiele, 1909 (Figures 46-60, 76, 79) Type locality: Not designated, but the following localities are given: Kagoshima; Hojo, Province Awa (Chiba Pre- fecture); Enoshima (Kanagawa Prefecture); Tsingtau; Gulf of Amur, east of Jankowsky Peninsula. Mopalia retifera THIELE, 1909:30-31, pl. 3, figs. 61-64, pl. 4, figs. 1-3; Is. & Iw. TAKI, 1929:148-153, figs. 32-43, pl. 2, fig. 2; LeLoup, 1942:57, fig. 26J; YAKOVLEVA, 1952:78-79, fig. 34, frontis. fig. 6, pl. 5, fig. 2; Is. AKI, 1955:203, fig. 4; KLIMOVA & SIRENKO, 1976:79, fig. 184; SIRENKO, 1976:90 (distribution); KAAS & VAN BELLE, 1980:110 (name only). Mopalia (Mopalia) retifera: Is. TAKI, 1962:33 (name only); Iw. TAKI, 1964:410-411 (name only). The Veliger, Vol. 34, No. 2 Mopalia (Mopalia) wosnessensku: ISHIKAWA, 1966:96, pl. 1, fig. 9 (in part, non MIDDENDORFF, 1847a). Material examined: See Table 4. Description: Animal medium in size, attaining 40 mm in body length, oblong in outline (Figures 46, 76). Valves: Head valve (Figure 47) semicircular, apex mod- erately elevated, anterior slope convex; tegmental surface with eight radiating rows of tubercular ribs, arranged in correspondence with siits; posterior edge dentate by some- what elongate tubercles; surface between ribs with fine reticulation; interior smooth and shiny; insertion plates squarish with nearly smooth surface; slits distinct, usually eight in number, bounded on each side by conspicuous upturned edge of insertion plates; slit rays perceptible as series of minute slitlike pores. Intermediate valves (Figure 48) rectangular, gently rounded at both corners of anterior margin, slightly beaked, moderately elevated and subcarinate at dorsal ridge, side slopes slightly convex; lateral areas only slightly elevated but clearly separated from central area by diagonal rib similar to tubercular ribs of head valve and bordered by dentate posterior margin; tegmental surface of central area regularly reticulate due to intersecting of inwardly arching longitudinal riblets and radial riblets originating from apex; mesh of reticulum squarish or rhomboid, fine and narrow at jugal area, gradually increasing in size toward margin; lateral areas with fine reticulation similar to surface be- tween ribs of head valve but somewhat coarser; interior smooth with slight transverse thickening; sutural laminae wide, rather short, anterior margin slightly arcuate, sep- arated by widely V-shaped sinus; insertion plates rather short, hardly projecting laterally beyond narrow spongy eaves; insertion plates and sutural laminae thickened and curved dorsally on sides of slit; slit rays not grooved, ap- pearing as whitish lines with series of minute pores. Tail valve (Figure 49) small, depressed, roughly tri- angular in outline, shallowly sinuated at posterior end; mucro hardly raised and situated near posterior third; anterior slope almost straight; central area sculptured like that of intermediate valves; posterior area granular; in- terior somewhat roughened, thickened along posterior edge; sutural laminae broad, anterior margin truncate or slightly concave, separated by V-shaped sinus; insertion plates short, obtuse at edge, posterior surface roughened; one slit per side; slit rays inconspicuous, perceptible as series of slitlike pores. Girdle: Girdle rather narrow, setose, slightly encroaching at sutures; perinotum covered by setae of various sizes and minute spicules; setae on side of sutures and around ter- minal valves (Figure 51) larger than others; each seta with long, curved, hyaline spicules, smooth or finely striated, pointed at tip, up to 650 um in length; smaller setae closely set near anterior margin, sparsely set on rest of perinotum, intermingling with minute ones; spicules on perinotum (Figure 53) minute, slender, hyaline or brownish in color, Page 185 H. Saito & T. Okutani, 1991 Explanation of Figures 46 to 50 49. 1909. Figure 46. body length 17.2 mm, from Muroran. Figures 47- from Shimoda. Figure 50. body length 6.0 mm, from Oshoro. > Figures 46-50. Mopalia retifera Thiele body length 16.5 mm > Figure 46. Dorsal view of animal. Figure 47. Head valve, dorsal and anterior views. Figure 48. Valve IV, dorsal and anterior views. and lateral views. > Figure 49. Tail valve, dorsal, ventral Figure 50. Dorsal view of young animal. Page 186 The Veliger, Vol. 34, No. 2 pi ai YL iv 58 58 5mm a Oils 52-55 Explanation of Figures 51 to 58 Figures 51-58. Mopalia retifera Thiele, 1909. Figures 51-55. body length 17.2 mm, from Amakusa. Figures 56, 57. body length ca. 24 mm, from Miyato. Figure 58. body length 23.5 mm, from Muroran. Figure 51. Seta, middle portion. Figure 52. Isolated bristles. Figure 53. Spicules on perinotum. Figure 54. Marginal spicules. Figure 55. Spicules on hyponotum. Figure 56. Radula, half row. Figure 57. Major uncinus, posterior and lateral views. Figure 58. Digestive tract, dorsal view. See Figures 1-13 for abbreviations. usually blunt at tip, striated near tip, 45-75 um in length; isolated bristle (Figure 52) near perinotal margin tipped with minute spicule, ca. 50 wm in length; marginal spicules (Figure 54) long, slender, hyaline, smooth or striated, pointed at tip, 140-185 um in length; spicules on hypono- tum (Figure 55) larger than those of perinotum, hyaline, smooth, rather blunt at tip, 70-115 wm in length; spicules on pallial fold similar to hyponotal spicules, but slightly more slender, 65-80 wm in length and very sparsely set. Radula (Figures 56, 57, 79): Central tooth roughly oblong in outline with distal cutting edge, slightly swollen at mid- dle of both sides, constricted and thickened posteriorly at bottom, concave at posterior surface, prop plate with round end; centro-lateral with small cusplike projection at outer lateral corner of dorsal edge, posterior portion strongly projected and reflexed posteriorly, propped by basal plate with obtuse end; major lateral with tridentate cusp; den- ticles pointed at tip, middle denticle longest, outer one smallest; shaft strongly keeled dorsally, dilated ventrally with prominent swelling inside of anterior portion; inner small lateral solid, much elevated, narrowly extended an- teriorly, deeply concave at outer lateral surface; outer small lateral also elevated, roundly sinuated at inner lateral sur- face, small but rather deeply sinuated at outer lateral sur- face; major uncinus (Figure 57) slender, spoon-shaped, cusp narrow, rounded at distal end; inner and middle marginals roughly rhomboid in shape, outer marginal squarish, thin, and platelike. Digestive tract (Figure 58): Stomach pouchlike, blind end situated at bottom or middle of right side of visceral mass; H. Saito & T. Okutani, 1991 20 ee oo) 2 @ oO e ee «co Oo 15 @ e°e . «e ra @ 3 @ Zz 10 0 10 Page 187 ® ry) eee @ ® © @ ® 20 30 40 Body length (mm) Figure 59 Relationship between body length and number of gills of Mopalia retifera (n = 37). anterior intestine originates from left side of stomach, dor- sally runs posteriorly to right with U-shaped loop; intes- tinal valve turns back and connects with posterior intestine; posterior intestine bends three times inside of U-shaped loop of anterior intestine, descends between beginning of anterior intestine and intestinal valve, then turns to right, runs posteriorly, loops one and a half times ventrally and leads back to rectum. Gills, gonopore, and nephridiopore: Gills merobran- chial and abanal, usually extending from under middle of valve III to under posterior margin of valve VII, with number of gills gradually increasing with growth (Figure 59); gonopore typically located between posterior second and third gills and nephridiopore situated one ctenidium behind the gonopore (between two posteriormost gills). Heart: Heart with one pair of auriculo-ventricular ostia. Coloration: Preserved valves variable in color, usually brownish or light brown with dark brown stripes along jugal area, but varying from red, orange, yellow to green mottled with irregular spots of various colors; perinotum usually light brown with darker bands; hyponotum uni- formly light brown; posterior end of girdle with orange spot which was present in all specimens preserved in al- cohol for ten years. Distribution: Sea of Japan, Pacific coast of Japan from southern part of Hokkaido to Ishigaki Island (25°N), Yel- low Sea (Figure 60), on rocks or underside of stones in littoral and sublittoral zones. The deepest record is 70 m in Peter the Great Bay (KLIMOVA & SIRENKO, 1976). Remarks: This species closely resembles Mopalia egretta Berry, 1919, in having regular reticulate sculpture. It is clearly separable from M. egretta by the sculptural mesh that narrows like a net pulled longitudinally at the jugal area, and the larger spicules of the setae. The tegmental sculpture changes with growth. The sculpture of the central area consists chiefly of simple lon- gitudinal riblets in an individual of 6 mm valve length (Figure 50). This sculpture in young individuals is similar to that of a young Mopalia seta (Figure 20). Genus Plaxiphora Gray, 1847a Type species: Chiton carmichaelis Gray, 1828 (S.D. by GRAY, 1847b). Remarks: FERREIRA (1982) stated that the type species of the genus Plaxiphora is Chiton carmichaelis Gray, 1828, despite the fact that PILSBRY (1893) and subsequent au- thors considered the type species to be Chiton auratus Spa- lowsky, 1795 (=Chiton setiger King & Broderip, 1831). Ferreira indicated that this species was originally desig- nated by Gray (1847a). However, Gray published three papers in 1847, dated 11 May, 25 May, and 9 November. He created this genus in the first paper (1847a), but the designation was made in the last one (1847b). So, the designation was by subsequent designation, not original designation. Plaxiphora integra (Is. Taki, 1954) (Figures 60-72, 77, 82) Type locality: Okataura, Okago-mura, Hachijo Island, Japan. Page 188 1202 LOY The Veliger, Vol. 34, No. 2 PACIFIC Figure 60 Distribution of Mopalia retifera and Plaxiphora integra. For M. retifera, localities indicated as follows: numbers (1- 11 and 14-19), this study (see Table 4); stars, THIELE (1909); solid circle, SIRENKO (1976). For P. integra, localities indicated as follows: numbers (11-13), this study (see Table 5) (type locality is 11). Mopalia (Hachijomopalia) integra Is. TAKI, 1954:60-65, figs. 1-13; Is. Taki, 1962:33 (name only); Iw. TAKI, 1964: 411 (name only). Hachijomopalia integra: Is. TAKI, 1955:202, 205, 207-208 (distribution). Plaxiphora integra: KAAS & VAN BELLE, 1980:64 (name only); VAN BELLE, 1983:110 (name only). Material examined: See Table 5. Description: Animal small, attaining 15 mm in body length, elliptical in outline (Figures 61, 77). Valves: Head valve (Figure 62) semicircular with eight weakly raised radial ribs; anterior slope slightly convex; tegmental granules oval or somewhat rhomboid, arranged in quincunx and not fused to each other; interior slightly undulated, thickened transversely at middle; insertion plates short, thick, obtuse, thicker at both sides of slit, and anterior surface slightly roughened; slits usually eight in number; eaves narrow, not very spongy; slit rays appear as white lines with some slitlike pores and not grooved. Intermediate valves (Figure 64) oblong, widest at valve V, slightly beaked, roundly projected at anterior margin of jugal area; side slopes slightly convex; lateral areas raised by two broad ribs; tegmental granules similar to those of head valve but tend to be fused and arranged in longitu- dinally arching rows in pleural portion of central area; interior smooth, shiny with transverse callus extending from center to near slits; sutural laminae rounded at an- terior edge, thin, separated by wide sinus; insertion plates short, not projecting laterally beyond narrow eaves; sutural laminae and insertion plates thickened at both sides of slit; one slit per side; slit rays appear as white lines with minute pores. Tail valve (Figure 63) small, flat, subtriangular, ante- rior margin nearly straight; mucro not raised, situated at posterior edge; anterior slope nearly straight; central area ornamented with granules like those of intermediate valves; posterior area very narrow, lying under diagonal ribs of posterior margin; interior with callus along posterior mar- gin; sutural laminae well projected anteriorly with truncate * Locality number corresponds to that in Figure 60. edge; insertion plate not distinguishable from posterior callus and bearing no slit. Girdle: Girdle narrow, slightly encroaching at sutures, scarcely sinuated at posterior end; perinotum covered by tufts of bristles and minute spicules; tufts comprised of 2- 4 bristles (Figure 65), larger ones on side of sutures and around terminal valves, others gradually becoming smaller toward periphery; each bristle long, up to 1.6 mm in length, light brownish in color, with slender hyaline spicule at distal end; spicules on perinotum (Figure 66) minute, smooth hyaline or brownish in color, blunt at tip, 55-100 um in length; marginal spicules (Figure 68) long, 265— 550 um in length, striated, hyaline or light brownish in color; spicules on hyponotum (Figure 67) minute, slender, smooth, pointed at tip, hyaline, 85-140 wm in length. Radula (Figures 69, 70, 82): Central tooth rather small, roughly rectangular, gradually narrowing ventrally, swol- len along midline at ventral half on posterior surface with distal arched cusp; centro-lateral with prominent cusp at lateral corner of dorsal edge, anterolaterally propped by well-projected basal plate; major lateral with long keeled H. Saito & T. Okutani, 1991 Page 189 ‘Table 4 Data of specimens of Mopailia retifera used in this study. Collecting depth Number of Locality* (m) individuals Body length (mm) Date collected Collector Pacific Coast 1. Muroran intertidal 5 16.5-29.7 10 Aug. 1983 Y. Kuwahara Muroran 0-1 2 Ney DOSS) 16 Aug. 1987 H. Saito 2. Hakodate intertidal 1 21.9 14 June 1987 S. Igarashi 3. Asamushi intertidal 5 15.4-23.0 5-6 Sep. 1986 S. Murakami 4. Ozuchi intertidal 1 1333 June 1987 Y. Kuwahara 5. Miyato 1 1 ca. 24 18 May 1986 H. Saito 6. Kominato intertidal 1 24.0 10 Apr. 1979 unknown Kominato 0-1 1 Zi 27 May 1981 unknown 7. Banda 1 1 39.0 26 Apr. 1986 H. Saito Banda 0-2 2 25.0, 26.4 6-7 June 1986 H. Saito Banda intertidal 1 ZO) 4 June 1989 T. Okutani Banda 0 1 ca. 23 17 Feb. 1988 J. Takahashi 8. Aburatsubo intertidal 4 8.2-11.9 8 Aug. 1986 S. Murakami 9. Shimoda 1 1 16.5 28 May 1986 R. Ueshima 10. Shikine Id. 2. 1 13.5 25 Aug. 1987 R. Inoue 11. Hachijo Id. 2-3 3 17.4-21.8 22 Mar. 1987 H. Saito 14. Kushimoto 5 1 10.8 15 Dec. 1987 I. Soyama 15. Ishigaki Id. 0-3 1 ca. 8 Mar. 1976 unknown Japan Sea 16. Oshoro intertidal 1 25.0 29 June 1983 Y. Kuwahara Oshoro 0-3 7 6.0-17.1 18 Aug. 1987 H. Saito 17. Oga intertidal 1 ca. 12 21 Aug. 1980 H. Watanabe 18. Kataku 0.3-0.5 2 15.0, 18.7 27 Mar. 1989 H. Saito East China Sea 19. Amakusa intertidal 1 27.0 19 Mar 1983 S. Nishihama Amakusa 0 1 NA 13 May 1987 Y. Takada Amakusa 0 1 5.6 11 June 1987 Y. Takada shaft and tridentate cusp; denticles are nearly equal in size, rather blunt; inner small lateral solid, elevated, posterior surface moderately sinuated; outer small lateral elevated and roughly rhomboid-shaped; major uncinus (Figure 70) spoon-shaped with rather long cusp; inner and middle marginals thick and platelike; outer marginal large, thin, and platelike. Digestive tract (Figure 71, 71a): Stomach pouchlike, broad, blind end situated at right side of visceral mass; anterior intestine originates from left side of stomach, runs poste- riorly to right, loops one and a quarter turns dorsally; intestinal valve bends and connects anteriorly with pos- terior intestine; posterior intestine runs along inside of anterior intestine, descends ventrally behind beginning of anterior intestine, then turns to right, revolves one and a half times ventrally, and leads back to rectum. Gills, gonopore, and nephridiopore: Gills holobranchial and abanal, anteriormost gill situated under posterior mar- gin of valve II, extending for about % of foot length, with the number increasing with growth (Figure 72); gonopore located between posterior second and third gills, and ne- The Veliger, Vol. 34, No. 2 Page 190 H. Saito & T. Okutani, 1991 30 up = @ e 1o)) @ w= 25 e : e° g ee @ E = * z 20 C eco e e 15 0) 5 1 15 20 Body length(mm) Figure 72 Relationship between body length and number of gills of Plax- iphora integra (n = 17). phridiopore situated one ctenidium behind the gonopore (between two posteriormost gills). Heart: Pericardium extending to boundary between valves V and VI; heart with two pairs of auriculo-ventricular ostia. Coloration: Preserved valve whitish with dark brownish wedge-shaped patterns in central area and mottled with brown, yellow, green, blue-green, or pink; girdle light brown with brownish bands; hyponotum uniformly light brown. Distribution: Hachijo Island and Ogasawara Islands (Figure 60), usually found on well-exposed rocks covered by coralline algae or on coralline-covered rocks in high Page 191 intertidal tidepools. ‘This species has been known only from the type locality, Hachijo Island (33°N). The present re- port extends the known range of distribution southward to the Ogasawara Islands (25°N). Remarks: Is. Taki (1954) created the subgenus Hachi- jomopalia for this species which he believed to be a Mopalia. He distinguished this subgenus from Mopalia s.s. by the absence of slits in the tail valve and from Plaxiphora by the absence of a spicule at the tip of the bristles. But, features of this species such as the granular surface of the tegmentum, slitless tail valve, and bunched bristles are not those of the genus Mopalia but rather of the genus Plax- iphora. KAAS & VAN BELLE (1980) and VAN BELLE (1983) previously transferred this species from Mopalia to Plax- iphora, but without discussion. Their treatment is quite appropriate because the spicules of the bristles were ob- served in this study. No generic difference is found between this species and species of the genus Plaxiphora. This species is related to a small-sized species group of Plaxiphora known from tropical and subtropical waters of the Pacific and Indian oceans: namely, Plaxiphora parva Nierstrasz, 1906, P. obscurellus (Souverbie & Montrouzier, 1866) [=P. primordia (Hull, 1924) fide STRACK (1986)], P. kamehamehae Ferreira & Bertsch, 1979, P. dardennei Leloup, 1981, P. tulearensis Leloup, 1981, and P. gweniae Ferreira, 1987. Among these, Plaxiphora integra seems to bear closest resemblance to P. kamehamehae. In fact, it is rather difficult to distinguish these two species. However, they are separated by a few characters, such as the higher dorsal ridge and longer tail valve in P. kamehamehae. The higher dorsal ridge may be caused by a difference in their habitat; P. integra lives chiefly on well-exposed, intertidal rock surfaces covered with coralline algae, whereas P. ka- mehamehae occurs in ““<1 metre of water, attached to the sides of dead coral pieces, usually occupying a depression Explanation of Figures 61 to 71 Figures 61-71. Plaxiphora integra (Is. Taki, 1954). Figure 61. body length 16.2 mm. Figures 62-70. body length 15.5 mm. Figure 71. body length 15.6 mm, from Hachijo Island. Figure 61. Dorsal view of animal. Figure 62. Head valve, dorsal and anterior views. Figure 63. Tail valve, dorsal, ventral, and lateral views. Figure 64. Valve IV, dorsal and anterior views. Figure 65. Bristles. Figure 66. Spicules on perinotum. Figure 67. Spicules on hyponotum. Figure 68. Marginal spicules. Figure 69. Radula, half row. Figure 70. Major uncinus, posterior and lateral views. Figure 71. Digestive tract, dorsal view. Figure 71a. Diagram of the course of posterior intestine. See Figures 1-13 for abbreviations. The Veliger, Vol. 34, No. 2 Table 5 Data of specimens of Plaxiphora integra used in this study. Page 192 Collecting depth Number of Body length Locality * (m) individuals (mm) 11. Hachijo Id. intertidal 12 8.1-16.2 12. Chichijima Id. intertidal 10 6.8-16.3 13. Iwojima Id. intertidal 1 ca. 13 * Locality number corresponds to that in Figure 60. or pit” (FERREIRA & BERTSCH, 1979). Even though the morphological differences between Japanese and Hawai- lan species are meagre, we believe that speciation has pro- ceeded with differentiation of water masses of the Pacific. The sporadic occurrence of other similar-looking species localized in small geographic areas of the Indo-Pacific may also be interpreted as evidence of a radiation from the common ancestor. The type specimens of this species are in the private collection of the Takis in Kyoto, inherited from the late Drs. Isao and Iwao Taki. ACKNOWLEDGMENTS Thanks are due to Mr. Kenjiro Konno and Dr. Susumu Segawa, Tokyo University of Fisheries, for their warm support and encouragement during the course of this study. Thanks are also due to the following persons for the loan of materials as well as for providing us with valuable specimens and information: Mr. Roger N. Clark, Oregon; Messers Hiroshi Hoshikawa, Tatsutaka Sawazaki, Su- guru Sugimoto, and Noriyoshi Takamaru, Hokkaido In- stitute of Mariculture; Mr. Shigeo Igarashi, Hakodate City; Mr. Kiyoshi Ito, Otaru City; Dr. Piet Kaas, National Museum of Natural History, Leiden; Yasuhiro Kuwa- hara, Wakkanai Fisheries Experimental Station; Miss Shiori Murakami, Tokyo University; Messers Shirou Ni- Date collected Collector 5 Mar. 1988 H. Saito, K. Tsuchiya 1-3 July 1989 H. Saito & K. Tsuchiya July 1985 K. Nishimura shihama and Yoshitake Takada, Kyushu University; Ka- zuhisa Nishimura, Tokyo Fisheries Experimental Station; Dr. Boris Sirenko, Academy of Sciences, Leningrad; Isamu Soyama, Fujisawa City; Mr. Hermann Strack, Rotterdam; Mrs. Ryoko Tsubokawa (née Inoue), Messers Hideki Nu- manami, and Kotaro Tsuchiya, Tokyo University of Fish- eries; Rei Ueshima, Tsukuba University; Hiroki Watana- be, Oga City. LITERATURE CITED ABBOTT, R. T. 1974. American Seashells. 2nd ed. Van Nos- trand Reinhold: New York. 663 pp., pls. 1-24. Berry, S. S. 1919. Preliminary notices of some new West American chitons. Lorquinia (Lorquin Natural History Club of the Southwest Museum) 2(6):44-47. CARPENTER, P. P. 1864. Supplementary report on the present knowledge with regard to the Mollusca of the west coast of North America. Reports of the British Association for the Advancement of Science for 1863:517-686. Cowan, G. I. McT. & I. McT. Cowan. 1977. A new chiton of the genus Mopalia from the northeast Pacific coast. Syesis 10:45-52. DaLL, W. H. 1879. Report on the limpets and chitons of the Alaskan and Arctic regions, with descriptions of genera and species believed to be new. Proceedings of the United States National Museum 1:281-344, pls. 1-5. DALL, W. H. 1889. Report on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico — Explanation of Figures 73 to 82 Figure 73. Mopalia middendorffii (Schrenck, 1861). Body length 28.1 mm, from Oshoro. Figure 74. Mopalia schrencki Thiele, 1909. Body length 15.6 mm, from Kitami-esashi. Figure 75. Mopalia seta Yakovleva, 1952. Body length 44.3 mm, from Hiroo. Figure 76. Mopalia retifera Thiele, 1909. Body length 16.5 mm, from Shimoda. Figure 77. Plaxiphora integra (Is. Taki, 1954). Body length 16.2 mm, from Okataura, Hachijo Island. Figure 78. Mopalia schrencki Thiele, 1909. Body length ca. 20 mm, from Rausu. SEM photograph of radula. Scale bar: 100 um. Figure 79. Mopalia retifera Thiele, 1909. Body length 23.5 mm, from Muroran. SEM photograph of radula. Scale bar: 100 um. Figure 80. Mopalia seta Yakovleva, 1952. Body length ca. 36 mm, from Muroran. SEM photograph of radula. Scale bar: 100 um. Figure 81. Mopalia middendorffu (Schrenck, 1861). Body length 16.9 mm, from Oshoro. SEM photograph of radula. Scale bar: 100 um. Figure 82. Plaxiphora integra (Is. Taki, 1954). Body length 15.5 mm, from Okataura, Hachijo Island. SEM photograph of radula. Scale bar: 100 ym. H. Saito & T. Okutani, 1991 Page 193 Page 194 (1877-78) and in the Caribbean Sea (1879-80), by the U.S. coast survey steamer “Blake,” lieut.-commander C. D. Sigs- bee, U.S.N., and commander J. R. Bartlett, U.S.N., com- manding. XXIV, Report on the Mollusca, Part I, Gas- tropoda and Scaphopoda. Bulletin of the Museum of Comparative Zoology at Harvard College 18:1-492, pls. 10- 40. DaLL, W. H. 1921. Summary of the marine shellbearing mol- lusks of the northwest coast of America, from San Diego, California, to the Polar Sea, mostly contained in the collec- tion of the United States National Museum, with illustra- tions of hitherto unfigured species. United States National Museum Bulletin 112:1-217, pls. 1-22. FERREIRA, A. J. 1982. Taxonomic notes on Chiton carmichaelis Gray, 1828, type species of Plaxiphora Gray, 1847. The Veliger 25(1):43-50. FERREIRA, A. J. 1987. The chiton fauna of the Marquesas Islands, with the description of a new species of Plaxiphora (Mollusca: Polyplacophora). Monitore zoologico italiano (n.s.) supplmento 22:177-191. FERREIRA, A. J. & H. BERTSCH. 1979. A new species of chiton (Mollusca: Polyplacophora) from the Hawaiian Islands and Tahiti. Transactions of the San Diego Society of Natural History 19(7):75-84. Gray, J. E. 1828. Spicilegia zoologia; or original figures and short systematic descriptions of new and unfigured animals. Part I. British Museum: London. 8 pp., 6 pls. Gray, J. E. 1847a. On the genera of the family Chitonidae. Proceedings of the Zoological Society of London 15:63-70. Gray, J. E. 1847b. A list of the genera of recent Mollusca, their synonyma and types. Proceedings of the Zoological Society of London 15(178):129-219. HuL., A. F. B. 1924. New Queensland loricates. Proceedings of the Royal Society of Queensland 36:109-116, pl. 21. IsHIKAWA, M. 1966. Classification of the class Polyplacophora, with a list of Hokkaido’s chitons. Seibutsu Kyozai (4):93- 102. Kaas, P. & R. A. VAN BELLE. 1980. Catalogue of living chitons. Dr. W. Backhuys: Rotterdam. 144 pp. Kinc, P. P. & W. J. BRODERIP. 1831. Description of the Cirrhipeda, Conchifera and Mollusca, in a collection formed by the officers of H. M. S. Adventure and Beagle employed between the years 1826 and 1830 in surveying the southern coasts of South America, including the Straits of Magalhaeus and the coast of Tierra del Fuego. Zoological Journal 5(18): 332-349. Kurmova, V. L. & B. I. SRENKO. 1976. Loricata. Jn: Animals and Plants of the Peter the Great Bay (Sea of Japan). Nauka. pp. 77-79, figs. 180-186. LELoup, E. 1942. Famille Mopaliidae. Mémoires Musée Roy- al d’Histoire Naturelle de Belgique, deuxiéme série, fasc. 25:1-64, pls. 1-6. LELoup, E. 1981. Chitons de Tuléar, Réunion, Maurice et Tahiti. Bulletin de l'Institut royal des sciences naturelles de Belgique 53(3):1-46, pls. 1-4. Lyons, W. G. 1988. Class Polyplacophora—chitons. Pp. 148- 150. In: D. Turgeon (ed.), Common and Scientific Names of Aquatic Invertebrates from the United States and Canada: Mollusks. American Fisheries Society Special Publication 16. MIpDENDOoRFF, A. T. VON. 1847a. Vorlaufige Anzeige bisher unbekannter Mollusken, als Vorarbeit zu einer Malaco- zoologica Rossica. Bulletin de la classe physico-mathéma- tique de l’Académie Imperiale des Sciences Saint Pétersbourg 6(8):113-122. MIDDENDOoRFF, A. T. VON. 1847b. Beitrage zu einer Mala- The Veliger, Vol. 34, No. 2 cozoologia Rossica. Mémoires de |’Académie Impériale des Sciences de Saint Pétersbourg 6:1-151, pls. 1-14. NIERSTRASZ, H. F. 1906. Beitrage zur Kenntniss der Fauna von Sud Afrika. VI. Chitonen aus der Kapkolonie und Natal. Zoologische Jahrbucher. Abteilung fiir Systematik, Geogra- phie und Biologie der Tiere 23:501-503, pls. 26-27. Pitsspry, H. A. 1893. Monograph of the Polyplacophora. Pp. 129-350, pls. 31-68. In: G. W. Tryon (ed.), Manual of Conchology. 14. Academy of Natural Sciences: Philadelphia. REEVE, L. A. 1847. Monograph of the genus Chiton. 28 pls., 194 figs. In: Conchologia Iconica, or Illustrations of the Shells of Molluscous Animals. 4. L. Reeve: London. SCHRENCK, L. 1861. Vorlaufige Diagnosen einiger neuer Mol- luskenarten aus der Meerenge der Tartarei und dem Nord- japanischen Meere. Mélanges Biologiques tires du Bulletin de l’Académie Impériale des Sciences de St.-Pétersbourg 4: 88-93. SCHRENCK, L. 1862 (1861). Vorlaufige Diagnosen einiger neu- rer Molluskenarten aus der Meerenge der Tartarei und dem Nordjapanischen Meere. Bulletin de l’ Académie Impériale des Sciences de St.-Pétersbourg 4:408-413. SCHRENCK, L. 1867. Reisen und Forschungen im Amur-lande in den Jahren 1854-1856 2(3), Mollusken des Amur-landes und des Nordjapanischen Meeres. 1, Specieller Theil. 1, Meeres-Mollusken. A, Gastropoda. 1, Chiton L. pp. 271- 291, pls. 12-13. Saint Petersburg. SIRENKO, B. I. 1976. Chitons from the Vostok Bay (Sea of Japan). Transactions 5, Academy of Sciences of the U.S.S.R. Far East Centre, Institute of Marine Biology:87-92. SIRENKO, B. I. 1985. Polyplacophora of the shelf of the South Sakhalin. Academy of Sciences of the U.S.S.R. Zoological Institute. Explorations of the Fauna of the Seas 30(38):346- 367. SOUVERBIE, ST.-M. & X. MONTROUZIER. 1866. Descriptions d’espéces nouvelles de l’Archipel Calédonian. Journal de Conchyliologie 3 serie, tome 6, 14:248-261, pl. 9. SOwERBY, G. B., II. 1840. Descriptions of some new chitons. Magazine of Natural History (n.s.) 4:287-294. SPALOWSKY, J. 1795. Prodromus in Systema Histricum Tes- taceorum. P. 88, fig. 6a, b: Wien. STRACK, H. L. 1986. Notes on New Caledonian chitons I. The species described by St.-M. Souverbie. Basteria 50:193-196. TaKI, Is. 1938. Report of the biological survey of Mutsu Bay 31. Studies on chiton of Mutsu Bay with general discussion on chitons of Japan. Science Reports of the Tohoku Imperial University series 4, 12(3):323-423, pls. 14-34. TakI, Is. 1954. A peculiar chiton from Hachijo-jima with spe- cial reference to its distribution in the Pacific. Records of Oceanographic Works in Japan 1(2) (n.s.):60-65. TakI, Is. 1955. Distribution of mopalioid chitons in the Pacific. Records of Oceanographic Works in Japan 2(1):29-53. Taki, Is. 1962. A list of the Polyplacophora from Japanese islands and vicinity. Venus 22(1):29-53. TaKI, Iw. 1964. Classification of the class Polyplacophora, with a list of Japanese chitons. Venus 22(4):401-414. THIELE, J. 1909. Revision des systems der Chitonen, 1. Zoolog- ica, Stuttgart 22(56):1-70, pls. 1-6. VAN BELLE, R. A. 1983. The systematic classification of the chitons (Mollusca: Polyplacophora). Informations de la So- ciete Belge Malacologie 11(1-3):1-178, pls. 1-13. YAKOVLEVA, A. M. 1952. Shell-bearing mollusks (Loricata) of the seas of the U.S.S.R. Zoological Institute of the Academy of Sciences of the U.S.S.R. (45):1-107, frontis., pls. 1-10 [English transl., 1965, i-viiit+105 pp., pls. 1-11. Smithson- ian Institution and National Science Foundation, by Israel Program for Scientific Translations: Washington, D.C.]. THE VELIGER © CMS, Inc., 1991 The Veliger 34(2):195-203 (April 1, 1991) Helicoradomenia juani gen. et sp. nov., a Pacific Hydrothermal Vent Aplacophora (Mollusca: Neomeniomorpha) by AMELIE H. SCHELTEMA Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA AND ALAN M. KUZIRIAN Marine Biological Laboratory, Woods Hole, Massachusetts 02543, USA Abstract. "The aplacophoran Helicoradomenia juani gen. et sp. nov. is found in large numbers at the northeast Pacific vent sites of Juan de Fuca Ridge, Explorer Ridge, and Gorda Ridge. It is placed in the family Simrothiellidae on the basis of radular morphology (distichous bars with paired ventral pockets) and is separated from other genera in the family by the presence of solid epidermal spicules. INTRODUCTION Several closely related species of neomenioid (footed) Apla- cophora occur at hydrothermal vents. They were originally assigned to the genus Simrothiella Pilsbry, 1878 (SCHEL- TEMA, 1988; TURNER, 1985, through personal communi- cation from Scheltema), but re-examination of type ma- terial of S$. margaritacea (Koren & Danielssen, 1877) indicates that the latter is generically distinct from the hydrothermal vent species on the basis of the radula alone (cf. Figure 2D, E). The type species for the new genus is described here. MATERIALS anp METHODS All specimens (365) were collected from the Endeavour segment of Juan de Fuca Ridge (47°57'N, 129°04-06'W, 2250 m), Explorer Ridge (49°46’N, 130°16’W, 1800 m), and Gorda Ridge (41°00'N, 127°30’W, 3271 m) from the deep submersible research vessels ALVIN and PISCES. About 20 specimens were dissected or sectioned. Rad- ulae, epidermal spicules, and copulatory spicules were dis- sociated from dissected anterior or posterior ends of spec- imens by dissolving tissue in hypochlorite solution (household bleach) or, for some radulae, in 10% NaOH solution. They were washed and placed in a drop of glycer- ine for camera lucida drawing. After further washing, permanent slides were made of air-dried spicules and CMCP-10 (TURTOX)-mounted radulae. One specimen was prepared for histology by decalcifying the spicules with 0.5 M EGTA overnight, dehydrating in dimethoxy propane, and embedding in epon/araldite epoxy resin. Sections were cut at 1.5 wm and stained with Richardson’s stain (azure II and methylene blue). Standard paraffin sections (7 um) were also cut and stained with Mallory- Heidenhain trichrome. Types are deposited in the Na- tional Museum of Natural History (NMNH), Washing- ton, DC. Terminology: Skeletal (=tangential) spicules are those that lie within the cuticle and spiral around the body at a 45° angle, crossing each other at 90°; upright (=radial) spicules extend out of the cuticle; zsochromes are boundaries between color bands produced in solid spicules by cross-polarized light; distachous refers to a radula formed by repeated rows of two teeth each (formula: number of rows x 1-1); den- ticulate bar is a bar-like radular tooth with denticles on the side opposite to the attachment of the tooth to the radular membrane; vestibule (=atrium) is the anterior cav- ity that lies above the mouth either united with or separate from the mouth opening and that contains sensory papillae; oral cavity (=buccal cavity) is the ventral space into which the mouth opens and which leads dorsally to the pharynx. Page 196 SYSTEMATICS Subclass Neomeniomorpha Pelseneer, 1906 Ventroplicida Boettger, 1956 Solenogastres Gegenbaur, 1878 (partim), Salvini-Plaw- en, 1967 Aplacophoran mollusks with a narrow foot in a ventral furrow, an anterodorsal vestibule with sensory papillae, a combined stomach-midgut gland, serial lateroventral mus- cles, a mantle cavity without ctenidia, and paired her- maphroditic gonads. Family SIMROTHIELLIDAE Salvini-Plawen, 1978 Type species: Solenopus margaritaceus Koren & Daniels- sen, 1877. Radula with distichous denticulate bars and short or long paired anteroventral radular pockets; spicules hollow or solid; skeletal spicules present or absent; morphology of ventral salivary glands varied. Helicoradomenia Scheltema & Kuzirian, gen. nov. Plump to somewhat elongate, nearly smooth to spiny, 5 mm or less in length, dorsoposterior sense organ and some- times dorsofrontal sensory pit present; proboscis large, pro- trusible; mouth at proximal end of vestibule; pedal pit large, often protruded; cuticle thin, epidermal glands not stalked; spicules solid, upright, skeletal spicules lacking; radula large, lateral denticles longest; radula spiraling into paired anteroventral radular pockets, first-formed teeth not retained; paired ventral salivary glands small, opening through paired ducts; paired sac-like seminal receptacles; single gametopore; copulatory spicule pockets paired, 2 or more long spicules per pocket; mantle cavity with long respiratory papillae. Range: Eastern and western Pacific hydrothermal vents. Etymology: helico = helical, rad = abbreviation for radula, menia = moon, usual ending for neomenioid (“new moon” aplacophorans. The Veliger, Vol. 34, No. 2 Helicoradomenia juani Scheltema & Kuzirian, sp. nov. (Figures 1—5) Holotype: 3.4 mm long, anterior diameter 0.7 mm, mid- body 1.0 mm, posterior 1.6 mm. Endeavour Segment, Juan de Fuca Ridge, 47°57'N, 129°04'W, 2250 m (DSRV AL- VIN Dive 1419). NMNH No. 836328. Figured paratypes: Nos. 1, 3, 6, 9, 14, from type locality. NMNH Nos. 860188, 860187, 860191, 860189, and 860190, respectively. Distribution: Explorer, Juan de Fuca, and Gorda ridges, 1800-3271 m. Diagnosis: Appearance fuzzy, length to 5 mm, narrowest anteriorly, mean index (length: diameter) at midbody 4:1; with dorsofrontal sensory pit; spicules widest at base and distally pointed, varying from short, wide, and recurved (110 wm long, 18 um wide, 10 um thick) to long, slender and curved (200 um long, 14 wm wide, more than 10 um thick); radular formula 34-35 x 1-1, teeth with 5 or 6 denticles, lateral denticle twice length of next adjacent one; 2 spicules per copulatory spicule pocket, curved, sharply pointed distally, up to 1 mm long, shorter spicule of pair with proximal process; accessory copulatory spicules 2 on each side, with 3 low bumps. External anatomy and hard parts: Body (Figures 1A- C, 2A) somewhat elongate, index at midbody 3-4:1; an- terior end rounded; wider posterior end slightly pointed with flattened ventral region around mantle cavity open- ing; mouth slit lateral; dorsofrontal sensory pit obvious as lateral slit; dorsoterminal sense organ not evident exter- nally; mantle cavity opening axial, oval. Epidermal spic- ules (Figure 3A, B) of 5 types, longest at posterior end of body, usually thickest near base: (1) evenly curved, narrow, width even except tapered distally to point, up to 130 um long < 11 um wide, 7 um to more than 10 um thick, grades into (2) straight or evenly curved, width even except ex- panded basally and tapered distally to blunt point, up to 200 um long xX 15 um wide, more than 10 wm thick; (3) broad, base recurved proximal to indentation or unevenly curved, distally tapered to point, up to 112 wm long x 18 Figure 1 Helicoradomenia juani gen. et sp. nov. A: Holotype, showing spicule orientation and somewhat protruded pedal pit, lateral (above) and ventral views. B: Holotype, anterior end, frontal view showing relationship of dorsofrontal sensory pit and opening to mouth and vestibule. C: Holotype, posterior end, ventral view, with oval-shaped mantle cavity opening. D: Schematic sagittal sections of anterior (above) and posterior ends; transverse sections 1-8 are keyed to histologic sections in Figures 4 and 5. E: Copulatory spicules in situ, paratype no. 3, ventral view of posterior end (rotated 90° from D, mantle opening below), tissue partially dissolved. Key: cg, cerebral ganglion; cs, copulatory spicule; dc, dorsal cecum; dsg, dorsal salivary gland; dso, dorsoterminal sense organ; dsp, dorsofrontal sensory pit; es, esophagus; f, foot; g, gonad; gd,,, upper and lower gametoducts; gp, gametopore; mc, mantle cavity; mg, midgut (stomach-intestine); mo, opening to vestibule and mouth; oc, oral cavity; p, pedal pit; pc, pericardial cavity; pg, pedal gland; ph, pharynx; re, rectum; rp, respiratory papilla; sr, seminal receptacle; v, ventricle; ve, vestibule; vsg, ventral salivary gland. Scale bars: A = 2.0 mm, B, C = 1.0 mm, E = 0.05 mm. A. H. Scheltema & A. M. Kuzirian, 1991 Page 197 The Veliger, Vol. 34, No. 2 Page 198 A. H. Scheltema & A. M. Kuzirian, 1991 um wide, 9 um or less thick; (4) short, straight, rounded basally, tapered distally to point, up to 74 wm long x 15 um wide, 7 um or less thick; (5) short, straight or curved, distally pointed, base straight, up to 80 um long x 11 wm wide, 9 um or less thick. Pedal-groove spicules short and broad, up to 70 wm long x 16 um wide, 4-5 um thick. Copulatory spicules (Figures 1D, E, 3D, E, 5C) 2 per pocket, curved dorsally, sharply pointed distally, longer spicule up to 1 mm in length with straight base, shorter spicule with proximal process, medioventral to and par- tially wrapped around longer spicule. Paired accessory spicules (Figures 3C, 5G) 2 on each side, recurved, each with 3 low bumps on base. Radula (Figures 2B, D, 3F, G) with single turn into ventral pockets; 34 or 35 rows; teeth with 5 or 6 denticles, lateralmost denticle twice length of next adjacent denticle; bar about 115 x 12 um, lateral denticle 30 um; dimensions of older teeth smaller. Internal anatomy (Figure 1D): Cuticle 22 um thick. Epi- dermis (Figure 2C) 22 wm thick, with more than one type of secretory cell, pierced by tubules from hemocoel. Body- wall musculature well developed. Pedal pit lined by large secretory cells (Figure 4A). Vestibule with few low, broad papillae; cirri grouped at mouth opening with which ves- tibule is united. Oral cavity deeply folded, also with cirri (Figure 4A). Multicellular dorsal salivary gland small (Figure 4A). Pharyngeal wall smooth (Figure 4B). Ventral salivary glands paired, small, tube-shaped, multicellular, unbranched, non-basophilic staining (Orange G), each opening through separate duct into anterior end of an- teroventral radular pocket (Figure 4C). Anteroventral rad- ular pocket as paired pouches which remain connected medially for some distance (Figure 4C). Radula bolsters large, bolster muscles well developed (Figure 4D). Short esophagus present (Figure 4D). With single, short dorsal midgut cecum (Figure 4D); midgut sacculate. Pericardial cavity large (Figure 5C); heart large, free within pericar- dium, opening from a posterior dorsal sinus (Figure 5C, D). Seminal receptacles as paired, large tubes lying in a dorsoanterior to ventroposterior position, each opening through a narrow tube leading dorsally to lower game- toduct (Figure 5A, B). Upper gametoduct opens into sem- Page 199 inal receptacle through a narrow duct adjacent to the tube joining the seminal receptacle and lower gametoduct (Fig- ure 5B). Gametopore single, opening into mantle cavity below rectum (Figure 5E). Mantle cavity with numerous long respiratory papillae (Figure 5F). Dorsoterminal sense organ large, papillate, seen only in sectioned material. Remarks: The reproductive system of these animals is unusual because (1) the upper gametoduct is joined to the distal end of the seminal receptacle rather than to the lower gametoduct, and (2) the position of the tubes connecting the seminal receptacles to upper and lower gametoducts is asymmetrical, being medial to the copulatory spicules on the left side and lateral to them on the right side in the specimen sectioned (Figure 5A, B). The ventral salivary glands are embedded in the muscles of the radula (Figure 4C). They are unusually small and do not have a basophilic reaction to trichrome staining. This condition is atypical from the strong basophilia found in the salivary glands of most other neomenioids and pre- sumably reflects diet. Nematocysts were not found in the midgut of Helicoradomenia juani, and Cnidaria did not occur where this species was collected. It is thus assumed that H. jwanz is not a cnidarivore as are most neomenioids. The organic matter seen in the gut has not been identified. Relationships: Isolated radulae have been examined from three genera belonging to the family Simrothiellidae Sal- vini-Plawen: Simrothiella Pilsbry, 1898 (Figure 2E), Krup- pomenia Nierstrasz, 1903a (synonymy with Simrothiella, SALVINI-PLAWEN, 1978, in error), and a new genus to be published which will include “Simrothiella” schizoradulata Salvini-Plawen, 1978. All have distichous bars and short to very long paired anteroventral radular pockets. It is this radular morphology that is the basis for placing Helicor- adomemaa in the Simrothiellidae. The epidermal spicules provide a basis for generic separation. In Helicorado- menia they are solid and thus differ from the hollow spic- ules found in all other genera in the family, which also includes Cyclomenia Nierstrasz, 1902, Uncimenia Nier- strasz, 1903b, Birasoherpia Salvini-Plawen, 1978, Biser- ramenia Salvini-Plawen, 1968, and Svaloherpia Salvini- Plawen, 1978. Although the illustrated radulae of these Figure 2 A-D. Helicoradomenia juani. A: Holotype, anterior to left (cf. Figure 1A). B: Scanning electron photomicrograph of part of left half of radula from above, medial edge to left, paratype no. 6; five rows of teeth, some with five and some with six denticles, shown. Arrowhead indicates longest, most lateral denticle. C: Light micrograph of histologic section of epidermis and cuticle (c) of mantle showing various gland cells and innervation by nerve fibers (arrowhead). D: Light micrograph of entire radula from below showing helical position of teeth from anteroventral radular pocket, paratype no. 14; newest tooth indicated by arrowhead. E. Light micrograph of radula of Svmrothiella margaritacea (Koren & Danielssen, 1877), ventral view with elongated paired ventral radular pockets to left and long lateral teeth (arrowhead) extending into pharynx on right (R. V. Chain 106 Stn 316, 50°58.7'N, 13°01.6’W, 2173 m). Species determination from comparison with radula isolated from a syntype, Bergen Museum no. 2078. Scale bars: A = 2.0 mm; B, C = 0.02 mm; D, E = 0.1 mm. Page 200 The Veliger, Vol. 34, No. 2 Figure 3 Helicoradomenia juani, hard part morphology. A, B: Epidermal spicules, anterior and posterior, respectively, paratype no. 1; selected isochromes indicated by dotted lines; 1-5, see text; 6, pedal-groove spicules; 7, oral spicule. C: Accessory copulatory spicules, paratype no. 1 (cf. Figure 5G). D, E: Copulatory spicules from paratype nos. 1 and 9, respectively. F: Two adjacent teeth from right side of radula, paratype no. 1. G: Single radular tooth, right side, paratype no. 1, view from beneath radular membrane showing bar. Scale bars: A, B, D, E = 0.1 mm; GC, F, G = 0.05 mm. A. H. Scheltema & A. M. Kuzirian, 1991 Page 201 Figure 4 Anterior end, Helicoradomenia juani, transverse histologic sections 1 through 4 of Figure 1D. A: Section 1 through cerebral ganglion, dorsal salivary gland, oral cavity with cirri (arrowhead), and pedal pit. B: Section 2 through oral cavity, pharynx, and pharyngeal muscles. C: Section 3 through paired ventral salivary glands (arrowheads), gland on left shown opening into anteroventral radular pocket. D: Section 4 through dorsal cecum of midgut, esophagus, radula and radula bolster with well-developed musculature and large chondroid-like cells. Key: CG, cerebral ganglion; DC, dorsal cecum; DSG, dorsal salivary gland; ES, esophagus; F, foot; OC, oral cavity; P, pedal pit; PG, pedal gland; PH, pharynx; PM, pharyngeal muscle; R, radula; RB, radula bolster; VP, anteroventral radular pocket. Asterisks indicate ganglia of lateral and anteroventral nerve cords. Scale bars: A~D = 0.1 mm. The Veliger, Vol. 34, No. 2 Wares SEDs Ne Oh A TENS A. H. Scheltema & A. M. Kuzirian, 1991 Page 203 latter five genera are drawn from sectioned material only, they all appear to be distichous denticulate bars. SALVINI-PLAWEN (1978) placed the family Simrothiel- lidae in the order Cavibelonia, a grouping based on pos- session of hollow spicules. Helicoradomemnia is the second genus with solid spicules to be placed in a cavibelonid family. The genera of Pararrhopalidae, if brought together on the basis of possessing fishhook-shaped spicules, also form a cavibelonid family with both solid (Ocheyoherpia) and hollow spicules (SCHELTEMA, in press). The families of Cavibelonia vary in respect to type of radula and ventral salivary glands and in presence or absence of skeletal spic- ules (SALVINI-PLAWEN, 1985). The morphologies of these structures are not unique to the Cavibelonia but are found in other orders as well. We therefore conclude that the order Cavibelonia is polyphyletic and needs to be revised. The family Simrothiellidae should probably be raised to ordinal level, but not until further comparisons of newly collected material have been made. Distribution: Several vent species of Helicoradomenia still to be described occur at other rift sites in the eastern Pacific other than those off the northwest United States where H. juanz is found: off the Galapagos (2 species), at 13°N (1 species), at 20°N (3 species, one in common with Galapagos), and from Gorda Ridge (1 species). The genus has also been collected from western Pacific rift sites in the Marianas Back Arc and Lau basins. None of these species has been collected in such high numbers as H. juan. ACKNOWLEDGMENTS Specimens were kindly provided by the late Joseph Rose- water of the National Museum of Natural History and Verena Tunnicliffe of the University of Victoria, British Columbia. We thank Catherine Tamse for her help in tissue preparation. The unflagging encouragement and generous gift of space and use of equipment by Rudolf Scheltema is gratefully acknowledged (AHS). Partial sup- port of this work came from a grant provided by Con- chologists of America, Inc. Contribution number 7465 from the Woods Hole Oceanographic Institution. LITERATURE CITED GEGENBAUR, C. 1878. Grundriss der Vergleichenden Anato- mie, 2nd ed. Wilhelm Engelmann: Leipzig. Koren, G. & D. C. DANIELSSEN. 1877. Beskrivelse over nye arter, henhrende til slaegten Solenopus, samt nogle oplys- ninger om densorganisation. Archiv for mathematik og Na- turvidenskab 2:120-128. Nrerstrasz, H. F. 1902. The Solenogastres of the Siboga- Expedition. Siboga-Expeditie 47. E. J. Brill: Leyden. 46 pp. NIERSTRASZ, H. F. 1903a. Kruppomenia minima n.g. n.sp., p. 249, pl. 7, fig. 5. In: S. Lo Bianco, Le pesche abissali .. . del Mediterraneo. Mittheilungen aus der Zoologischen Sta- tion zu Neapal 16:109-278. NIERSTRASZ, H. F. 1903b. Neue Solenogastren. Zoologische Jahrbucher, Abteilung ftir Anatomie und Ontogenie der Thiere 18:359-386. PELSENEER, P. 1906. A treatise on zoology. Jn: E. R. Lankester (ed.), Part 5, Mollusca. Black: London. Pitssry, H. A. 1898. Order Aplacophora v. Ihering. Tryon’s Manual of Conchology 17:281-310. SALVINI-PLAWEN, L. v. 1967. Neue Scandinavische Aplacopho- ra (Mollusca, Aculifera). Sarsia 27:1-63. SALVINI-PLAWEN, L. v. 1968. Neue Formen im marinen Me- sopsammon: Kamptozoa und Aculifera (nebst der fiir Adria neuen Sandfauna). Annalen des Naturhistorischen Muse- ums in Wien 72:231-272. SALVINI-PLAWEN, L. v. 1978. Antarktische und subantarktische Solenogastres (eine Monographie: 1898-1984). Zoologica (Stuttgart) 44:1-315. SALVINI-PLAWEN, L. v. 1985. Early evolution and the primitive groups. Pp. 59-150. In: E. R. Trueman & M. R. Clarke (eds.), The Mollusca. Vol. 10. Evolution. Academic Press, Inc.: Orlando. SCHELTEMA, A. H. 1988. Ancestors and descendents: relation- ships of the Aplacophora and Polyplacophora. American Malacological Bulletin 6:57-68. SCHELTEMA, A. H. In press. Class Aplacophora. Jn: D. Walton & P. Beesley (eds.), Fauna of Australia. Vol. 5. Mollusca. Australian Biological Resources Study, Canberra. TuRNER, R. D. 1985. Notes on the mollusks of deep-sea vents and reducing sediments. American Malacological Bulletin Special Edition 1:23-34. Figure 5 Posterior end, Helicoradomenia juani, transverse histologic sections 5 through 8 of Figure 1D. A, B: Section 5, left and right sides, respectively, showing the connections between the upper and lower gametoducts and the paired seminal receptacles; position of ducts on left side lies between copulatory spicules and midgut, whereas those on right lie lateral to the copulatory spicules. C: Section 6 through pericardium with ovum, heart, upper and lower gametoducts, and copulatory spicule pockets. D: Section 7 through posterior end of pericardial cavity where it connects to upper gametoduct, beginning of auricle, rectum and suprarectal commissure arising from large ganglion of the lateral nerve cord (asterisk). E: Unnumbered section between sections 7 and 8 through proximal end of mantle cavity just anterior to openings of rectum and gametopore and through the copulatory spicule glands (arrowheads). F: Section 8 through mantle cavity with long respiratory papillae. G: Unnumbered section posterior to F through the accessory copulatory spicules (dissolved) of the mantle, bump indicated by arrowhead (cf. Figure 3C). Key: 1, upper gametoduct; 2, lower gametoduct; AS, accessory copulatory spicule; AU, auricle; CS, copulatory spicule/spicule pocket; GP, gametopore; MC, mantle cavity; MG, midgut gland; OV, ovum; PC, pericardial cavity; R, rectum; SC, suprarectal commissure; SR, seminal receptacle; V, ventricle. Scale bars: A-C, E, F = 0.1 mm; D, G = 0.05 mm. The Veliger 34(2):204-213 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Chaetoderma argenteum Heath, a Northeastern Pacific Aplacophoran Mollusk Redescribed (Chaetodermomorpha: Chaetodermatidae) AMELIE H. SCHELTEMA Biology Department, Woods Hole Oceanographic Institution, Woods Hole, Massachusetts 02543, USA JOHN BUCKLAND-NICKS Department of Biology, St. Francis Xavier University, Antigonish, Nova Scotia, Canada B2G 1C0 FU-SHIANG CHIA Department of Zoology, University of Alberta, Edmonton, Alberta, Canada T6G 2E9 Abstract. Chaetoderma argenteum Heath, 1911, has been collected in the northeast Pacific from Point Conception, California, to southeast Alaska between 70 and 600 m. Synonyms are C. attenuata Heath, 1911, and C. montereyensis Heath, 1911. Since 1960, several surveys have taken C. argenteum from the Santa Maria Basin, from off the Oregon coast, and from both offshore and inshore waters of southwest British Columbia in numbers large enough to provide material for experimental research. Chaetoderma argenteum is redescribed and illustrated. It is distinguished from all other Chaetoderma species of the east Pacific by the anterior trunk spicules, which are bent and thickened on each side of an abfrontal groove, and by the large radula cone, which is curved in lateral view. INTRODUCTION Chaetoderma argenteum Heath, 1911, can predictably be collected from off southwestern Vancouver Island, British Columbia, from fine silt sediments, between 100 and 200 m. Specimens from this locality provided material for the first published account of spermiogenesis in a chaetoderm aplacophoran (BUCKLAND-NICKS & CHIA, 1989). The spe- cies has also recently been collected from inshore waters of British Columbia, from off the Oregon coast, and from the Santa Maria Basin off southern California. It thus appears to occur in large enough numbers at specific lo- calities to provide material for fine structural analysis of anatomy and larval development, both of which are poorly studied in this group. HEATH’s (1911) original descriptions are not adequate for accurate species identification; he even mistook different sizes of Chaetoderma argenteum for different species. Therefore this species is redescribed by external anatomy and morphology of hard parts using the criteria of SCHEL- TEMA (1976, 1989). MATERIALS anD METHODS Two hundred eleven specimens have been examined: 13 certain holotype and paratype specimens and 26 presumed paratypes collected between 1903 and 1904 by the U.S. Fisheries steamer Albatross (Table 1) and 172 recently collected specimens (Table 2). Most of the recently col- lected specimens were fixed as part of entire quantitative grab samples and sorted post-fixation. The fixatives used were not known to the authors; preservation was in buf- fered alcohol. Specimens used for scanning electron mi- croscopy (SEM) were sorted alive, dissected, and then fixed in 2% glutaraldehyde buffered with 0.2 M sodium caco- A. H. Scheltema e¢ al., 1991 Page 205 Table 1 Chaetoderma argenteum Heath, 1911, extant type material re-examined. No. specimens Date Listed by Albatross! station Locality Depth (m) (day/mo/yr) Heath Extant Source? 4231 Naha Bay, SE Alaska 148-203 7/VII/03 1 1, slides? CAS 4244 Kasaan Bay, SE Alaska 90-97 11/VII/03 1 — — 4244, 4250 Samples mixed — _— — 3 MCZ 4250 off Stikine R., SE Alaska 110-119 13/VII/03 5 1 MCZ 1, slides? CAS 4252 Stephens Passage, SE Alaska 356-362 14/VII/03 2 2 MCZ 4485 Monterey Bay 70-194 17/V /04 9 — — 4508 Monterey Bay 526-640 20/V /04 i — — 4510+ Monterey Bay 164-331 ?/V/04 — 19 MCZ 4522 Monterey Bay 234-268 26/V/04 © 1 MCZ 4523 Monterey Bay 135-194 26/V /04 139 1 MCZ 4524 Monterey Bay 383-410 26/V /04 2 MCZ 4525 Monterey Bay 400 26/V /04 — — 45264 Monterey Bay 367 26/V /04 — 7 MCZ n.d. Monterey Bay n.d. n.d. 1 1, slides? CAS ‘From U.S. COMMISSION OF FISH AND FISHERIES (1905) and U.S. BUREAU OF FISHERIES (1906). * CAS = California Academy of Sciences; MCZ = Museum of Comparative Zoology (Harvard University). > Holotypes. * Not listed by HEATH (1911) but specimens were presumably examined by him and are considered to be paratypes. dylate buffer (pH 7.4) at 4°C for 2 h. Following a rinse in the same buffer, tissues were post-fixed in 1% osmium tetroxide in the same buffer at 4°C for 1 h. The tissues were dehydrated in an ethanol series, exchanged in incre- mental steps through amy] acetate, and critical point dried. Selected body parts were mounted on SEM stubs, sputter coated with gold, and examined in a Cambridge S250 stereoscan scanning electron microscope. Spicules used for camera lucida drawings were removed from alcohol-preserved specimens with a fine needle and transferred by pipette into glycerine; or the specimen was placed directly into glycerine before removing the spicules. For SEM, segments of specific areas of the body were isolated and treated with 2% sodium hypochlorite (house- hold bleach) until the tissues were dissolved. Spicules were removed from the dish with a Pasteur pipette, passed through three rinses of distilled water, transferred into ethanol, and then air dried on SEM stubs. The spicules were sputter coated with gold prior to examination. Rad- ulae for camera lucida drawings were dissected by making a dorsal longitudinal slit in the head region, removing the entire buccal mass, and dissolving the tissue in hypochlorite solution. The radulae were washed thoroughly and placed in glycerine for drawing. Preparation of radulae for SEM was similar to that for spicules. Body measurements of entire preserved specimens were made from camera lucida drawings with dividers or a map- measuring wheel, and of sectioned type material with scale bars drawn on camera lucida drawings. Type material is at the California Academy of Sciences (CAS) and Museum of Comparative Zoology (Harvard University) (MCZ). Table 2 Chaetoderma argenteum Heath examined from recent collections. No. Locality Depth (m) specimens Source! Off SW Vancouver Is., BC 100-200 96 SEATECH-IOS; Buckland-Nicks Alice Arm, Hastings Arm, of Observatory Inlet, BC 400-600 36 IOS Saanich Inlet, BC 90 4 D. A. Bright, Univ. Victoria Off Oregon coast 150-200 11 OSU Santa Maria Basin 113-410 25? MMS; Santa Barbara Museum ' SEATECH-IOS = Canadian Government Survey, Institute of Ocean Sciences, Sidney, BC; OSU = Oregon State University; MMS = Minerals Management Service, U.S. Department of Interior. * Voucher specimens only. Page 206 The Veliger, Vol. 34, No. 2 Figure 1 Chaetoderma argenteum Heath. Chaetoderma montereyensis Heath paratype (Albatross stn. 4524) (MCZ). Above, entire specimen showing body regions: A, anterium; B, neck; C, anterior trunk; D, posterior trunk; E, posterium; and positions 1-8 from which spicules were drawn (see Figure 3); scale bar = 5.0 mm. Lower left, posterium showing extended ctenidia (cf. Figure 2C) and dorsoterminal sense organ (dso); lower right, oral shield with dorsal cleft around mouth opening (mo) (cf. Figure 2D). Lower left and right, same paratype as above; scale bars = 1.0 mm. SYSTEMATICS Subclass Chaetodermomorpha Pelseneer, 1906 Caudofoveata Boettger, 1956 Aplacophoran mollusks without a foot or ventral groove; with a cuticular oral shield and paired ctenidia in the mantle cavity; stomach and digestive gland separate; di- oecious. Family CHAETODERMATIDAE Marion, 1885 Oral shield unpaired; radula with a cone-shaped cuticular piece (=peg, tongue) and a single pair of denticles; body with four distinct regions reflecting internal anatomy. Chaetoderma Loven, 1844 Crystallophrisson Mobius, 1875. IVANOV, 1981 (see SALVI- NI-PLAWEN, 1984). Type species: Chaetoderma nitidulum Loven, 1844, by monotypy. Radula with paired denticles lying outside dome-shaped cuticular membrane that covers buccal mass and with paired lateral projections extending from radula cone to dome- shaped membrane beneath base of denticles (see SCHEL- TEMA, 1972). Range: Worldwide from 8 to 2260 m. Chaetoderma argenteum Heath, 1911 Chaetoderma argentea HEATH, 1911:43, 62-63, pl. 4 fig. 7, pl. 26 figs. 1-7, pl. 36 fig. 1, pl. 37 fig. 6 (SE Alaska, Behm Canal, near Naha Bay, 148-203 m; Albatross stn. 4231, 7/VI1I/03. Type: Holotype as serial sections and spicules, CAS 021392. Described from single specimen. Chaetoderma attenuata HEATH, 1911:43, 55-59, pl. 4 figs. 3, 10, pl. 5 fig. 1, pl. 12 fig. 4, pl. 25 figs. 1-10 [figs. 1- 3, 6, 7 of type], pl. 36 fig. 2, pl. 37 fig. 8 (SE Alaska, Stikine River delta, 110-119 m; Albatross stn. 4250, 13/ VII/03). Types: Holotype as serial sections and spic- ules, CAS 021393; paratypes as 6 wet specimens, MCZ. Chaetoderma montereyensis HEATH, 1911:43, 61-62, pl. 4 figs. 4, 8, 14, 17, pl. 27 figs. 1, 2, 4-11 [figs. 2, 5, 7-9 of type], pl. 37 figs. 2, 3 (Monterey Bay, California) (no Albatross stn. no.). Types: Holotype as serial sec- tions, no spicule slide, CAS 021397; 4 certain and 26 probable paratypes as wet specimens, MCZ. ?Crystallophrisson rafanovi IVANOV, 1984. [Caudofoveata (Mollusca, Caudofoveata) in Peter the Great Bay (Sea of Japan)] pp. 36-37, fig. 4. [In Russian.] Chaetoderma sp. BUCKLAND-NIcks & Cui, 1989:308-317, figs. 1-22. A. H. Scheltema et al., 1991 Page 207 Figure 2 Chaetoderma argenteum Heath from 110 m adjacent to Rainy Bay, Vancouver Island, BC. A, B: Living specimens showing change in shape caused by muscle contraction and hydrostatic expansion. Arrowheads indicate boundaries between body regions (cf. Figure 1). C: Ctenidia extended from mantle cavity, scanning electron photomicrograph (SEM); long axes indicate dorsally situated efferent channels, and ctenidial leaves are alternate. D: Oral shield with open mouth (mo); arrowheads indicate edge of cuticle at dorsal cleft. Note that ventral part of shield appears thicker than dorsal part around mouth. Scale bars: A, B = 3 mm, C, D = 200 um. Range: Off Pt. Conception, California, to southeast Alas- ka, from 70 to 640 m; ?Sea of Japan, 33-69 m. Diagnosis: Greatest length to more than 40 mm; anterior constriction pronounced; anterior trunk usually longer than posterior trunk and often narrower than neck; posterior trunk up to 2.0 mm in diameter. Oral shield with dorsal cleft. Spicules erect on anterior trunk and flat against pos- terior trunk. Spicules widest at base, those of anterior trunk bent, thickened on each side of base forming abfrontal groove, up to 130 wm long, those of posterior trunk py- ramidal, flat, keeled, with two or more sharp lateral ridges, up to 263 wm; radula cone large, up to 510 um long, curved, wider laterally than frontally, lateral projections up to 250 um long. DESCRIPTION Body: Preserved, contracted specimens of Chaetoderma ar- genteum typically have an anterior trunk (region C) either Page 208 Table 3 The Veliger, Vol. 34, No. Body measurements and ratios of specimens belonging to Heath types of Chaetoderma argenteum, C. attenuata, and C. montereyensis. Measurements (mm) Body length Neck (B) diam.! Ant. trunk (C) diam.! Post. trunk (D) diam.'! Species ar. at. m. ar. at. m. ar. at. mM. ar. at. m. Heath, 1911? 24 45,61 45 — — — 1.6 Nos, to7 2, 2.6 2.6, 2.7 3) Type slides EZ, — — 0.8 0.5 eS 1.1 0.8 14 Paratypes* — 39-42 14-34 — 1.0-1.6 0.8-1.5 — 0.8-1.2 0.8-1.4 — 1.1-1.9 0.8-2.0 Ratios B/C diam. C/D length C/D diam. ar. at. m ar. at. m. ar. at. m. Computed from Heath, 1911 _ — — — — — 0.62 0.65 0.67 Type slides 1.50 _- 1.46% — — 0.72 0.62 0.93 Paratypes’ (mean) — 1.26 1.05 — 1.45 1.10 — 0.64 0.80 'See Figure 1 for body regions. ? Heath does not state whether these are measurements of alive or fixed animals. > For C. montereyensis, all Albatross specimens are considered to be paratypes. * Determined from pl. 4, fig. 7 (HEATH, 1911). equal in diameter to or narrower than the neck (region B) and longer than the posterior trunk (region D) (Figure 1, Table 3). In living specimens the relative lengths of the two trunk regions change, reflecting movements under hy- drostatic control (cf. Figure 2A, B). The erect spicules of the neck and anterior trunk are dense; the flat-lying spic- ules of the posterior trunk are more sparse. The oral shield is cleft dorsally (Figures 1, 2), a morphology that was recognized by HEATH (1911) in C. attenuata, but that he illustrated incorrectly in C. montereyensis as being pierced by the mouth opening (HEATH, 1911:pl. 4, figs. 14, 17). Posteriorly the dorsoterminal sense organ is obvious and about 1 mm in length in large specimens. The spicules of the posterium do not form a terminal ring. Spicules: Spicules from all body regions are widest basally and range up to more than 10 wm in thickness. Neck spicules (no. 1, Figures 3, 5) are mostly narrow, thickest medially at the flared base, and curved in lateral view; they are less than 100 ym long and up to 25 um wide. Spicules from the anterior trunk are longest near the an- terior constriction (no. 2), up to 130 wm in length, de- creasing to 90 um at the midpoint (no. 3) and to 80 um next to the posterior trunk (no. 4). All are thickened on each side abfrontally producing a groove (Figures 3, iso- chromes; 5E) and all are bent and flared basally, ranging up to 40 um wide. Spicules near the posterior trunk bear a sharp keel (no. 4). Spicules on the posterior trunk region change abruptly; they are flat, sharply keeled with one or more sharp or rounded lateral ridges on each side, and gradually tapered from the broad base (nos. 5-7). Length increases from a maximum of 170 wm anteriorly to 265 um posteriorly and greatest width at the base increases from 50 to 60 um. Thickness exceeds 10 um only medially on the keel. There are numerous fine axial striations on the base (Figure 5C). Spicules of the posterium are without a keel, more than 400 um long, 40 wm or more wide, and thickest medially (no. 8). Radula: The cone-shaped piece is large, up to 510 um long, 140 wm wide in frontal view, and 190 wm wide in lateral view (Figures 4, 5); in lateral view it curves and tapers to a narrow end. The lateral projections are broad and up to 250 um long. Denticles are rather small, between 30 and 60 um long. The cuticular dome extends proximally one-half the length of the cone. (Measurements based on five isolated redulae.) REMARKS Heath considered Chaetoderma argenteum of different sizes or from geographically separated populations as distinct species, although he did not differentiate C. argenteum, C. attenuata, and C. montereyensis either by written descrip- tion or by illustration. STORK (1941) already noted the similarity between C. attenuata and C. montereyensis in Heath’s descriptions. In several characters examined here in types and newly collected specimens, no differences at a species level were detected among the three Chaetoderma species described by Heath. Precedence is given to the name C. argenteum because of its page position (HEATH, 1911: 43). The lengths and diameters of body regions and their ratios are shown in Table 3 for Heath’s types and para- types. Although total body length as published by Heath and measured on types is seen to differ among his species, A. H. Scheltema e al., 1991 Page 209 Figure 3 Spicules of Chaetoderma argenteum Heath. Lateral views with long axis horizontal; isochromes (lines of equal thickness as seen under cross-polarized light) indicated by dotted lines. A: Holotype spicules, C. argenteum, CAS 021392. B: Holotype spicules, C. attenuata Heath, CAS 021393. C: Paratype spicules, C. attenuata (Albatross stn. 4252, MCZ); numbers refer to body positions indicated in Figure 1. D: Paratype spicules, C. montereyensis, from specimen drawn in Figure 1 showing positions 1-8 from which spicules were drawn. Scale bar = 200 wm, except for spicule D8 = 500 um. Page 210 The Veliger, Vol. 34, No. 2 Figure 4 Radula of Chaetoderma argenteum Heath (cf. Figure 5C, D). 1: Frontal and lateral views of C. attenuata Heath paratype (MCZ) (Albatross stn. 4252). 2: Lateral and frontal views of C. montereyensis Heath, specimen presumed part of type series (MCZ) (Albatross stn. 4510). 3: Section of C. attenuata Heath holotype (CAS 021393). 4: Two sections of C. argenteum Heath holotype (CAS 021392). 5: Section of C. montereyensis Heath holotype (CAS 021397). Arrowheads indicate lateral projections. Scale bars = 200 um. measured diameters of the neck (region B), anterior trunk (region C), and posterior trunk (region D) fall within the same ranges (0.8-1.6 mm, 0.5-1.4 mm, and 0.8-2.0 mm, respectively). The ratios of neck to anterior trunk diam- eters, anterior to posterior trunk diameters, and anterior to posterior trunk lengths are also similar. In particular, the neck is usually wider than the anterior trunk (ratios 1.50, 1.26, and 1.05 for Heath’s three species) and the anterior trunk is longer on average than the posterior trunk (ratios 1.46, 1.45, and 1.10). The oral shield is unknown for the single specimen of Chaetoderma argenteum described by Heath, but shields of paratypes of C. attenuata and C. montereyensis do not differ either in size or in being dorsally cleft, despite HEATH’s qualitative judgments of differences in relative size (1911: 43) or incorrect illustrations (1911:pl. 4, figs. 14, 17). Heath fortunately made permanent spicule slides from the holotypes of Chaetoderma argenteum and C. attenuata. Paratypes of C. montereyensis and C. attenuata remained in good condition after nearly 90 years in alcohol and provided spicules from discrete body regions (Figures 1, 3). All of Heath’s species have the diagnostic short, bent spicules with a broadly flared base and lateral abfrontal thickenings. These spicules are carried erect on the anterior trunk of C. attenuata and C. montereyensis paratypes. The same spicule attitude is indicated in the sections of the C. argenteum holotype, where the arrangement of spaces left by dissolved spicules in the cuticle of the anterior trunk Figure 5 Chaetoderma argenteum Health: spicules (A-E, scanning electron micrographs, cf. Figure 3) and radulae (F, light microscope, G, SEM, cf. Figure 4) from specimens recently collected off Rainy Bay, BC. A: From neck region. B, E: From anterior trunk; arrowhead on E indicates abfrontal view of broad lateral ridges and groove. C: From posterior trunk. D: From posterium. F: Frontal view, lateral projections (double arrowhead) and denticles (single arrowhead) seen in transmitted light. Note that cone becomes progressively tanned distally. G: Dome-shaped cuticular hood covering buccal mass as seen with SEM; denticles (arrowhead) lie outside of cuticular dome. Scale bars: A, B, E = 20 um; C, D, F, G = 100 um. A. H. Scheltema e¢ al., 1991 Page 211 Page 212 are the same as the spicule spaces in C. attenuata and C. montereyensis holotype sections from the same body region. The morphology of spicules from the anterior trunk sep- arates C. argenteum from all other eastern Pacific Chae- toderma species. The radulae from paratypes of Chaetoderma attenuata and C. montereyensis are morphologically indistinguish- able. The cone is wide and curved in lateral view and the lateral projections are long and broad (Figure 4). The radula is broken in the holotype sections of C. argenteum, but size of the radula in relation to section diameter and size of the lateral projections are similar to those in ho- lotype sections of C. attenuata and C. montereyensis (Figure 4, radulae 3, 4, 5). A comparison of HEATH’s (1911) written descriptions and examination of type sections of Chaetoderma argen- teum, C. attenuata, and C. montereyensis offer no specific differences. Finally, new collections of Aplacophora from areas close to the type localities of C. argenteum and C. attenuata contain only a single species with bent, laterally thickened anterior trunk spicules. Therefore, we can con- clude with a high degree of certainty that the synonymy is justified. GEOGRAPHIC DISTRIBUTION Including Chaetoderma argenteum and its synonyms, HEATH (1911) named eight northeast Pacific Chaetoderma species from Albatross collections. SCHWABL (1963) added nine further species from southern California collected during the Pacific Expedition of the Allan Hancock Foundation. Examination of Schwabl and Heath types indicates a re- duction of these species by synonymy to perhaps 10 species, including C. argenteum. The number of Chaetoderma spe- cies known worldwide is about 37 to date; thus, approx- imately one-quarter of known species occurs in the north- east Pacific. The genus ranges in depth from 8 to 2260 m, but only a few species are restricted to depths less than 100 m or extend to more than 1000 m. The northeast Pacific species fit this depth pattern and are thus members of the upper continental slope fauna. Chaetoderma argenteum has an amphi-Pacific distribu- tion if C7rystallophrisson kafanovi Ivanov (=Chaetoderma ka- fanovi) from the Sea of Japan is a synonym. There is at least one other probable amphi-oceanic Chaetoderma spe- cies. In the northern Atlantic, C. nitidulum, known as C. nitidulum canadense Nierstrasz in the western Atlantic (SCHELTEMA, 1973) (but considered a distinct species by SALVINI-PLAWEN, 1978), seems to occur on both sides of the ocean. In 1904 numerous specimens of Chaetoderma argenteum were taken by the Albatross in Monterey Bay (Table 1), but since then it has been replaced by another unidentified species probably related to a form found south of Pt. Con- ception. However, C. argenteum has recently been collected south of Monterey Bay in the Santa Maria Basin from 113 to 410 m (Table 2). The Veliger, Vol. 34, No. 2 ENVIRONMENT In two studies of the effects of mine tailings on density and distribution of the invertebrate fauna in the inner reaches of Observatory Inlet, British Columbia (KATHMAN et al., 1983, 1984), Chaetoderma argenteum was too scarce to be used as an indicator species. The study did show that the species was most abundant (50 m~) in sediments of fine silt and clay near the sill at depths between 400 and 600 m, an area physically, chemically, and biologically different from the inner reaches. Adjacent to Rainy Bay, near Bamfield, Vancouver Island, British Columbia, Chae- toderma argenteum has repeatedly been found in similar fine silts at 110 m. It seems that the most likely sites for finding C. argenteum are the fjords and inlets of Canada and southeast Alaska in silty muds at depths greater than 100 m. ACKNOWLEDGMENTS Provision of type material from the California Academy of Sciences and the Museum of Comparative Zoology, Harvard University, is gratefully acknowledged. We thank Dr. Ralph O. Brinkhurst, Institute of Ocean Sciences, Sidney, BC, and Dr. Andrew G. Carey, Jr., Oregon State University, Corvallis, OR, for providing us with specimens from Vancouver and Oregon. Dr. Alan M. Kuzirian kind- ly read the manuscript. We are also grateful to George Braybrook for technical assistance with the scanning elec- tron microscope. Santa Maria Basin specimens were re- ceived under contract No. 14-35-0001-30484 from Min- erals Management Service, U.S. Department of Interior, to Science Applications International Corporation, Woods Hole, MA. This study has been supported in part by NSERC of Canada grants to J.B.-N. and F.-S.C. Contribution no. 7512 of the Woods Hole Oceanograph- ic Institution. LITERATURE CITED BUCKLAND-NICKS, J. & F.-S. Cuta. 1989. Spermiogenesis in Chaetoderma sp. (Aplacophora). Journal of Experimental Zoology 252:308-317. HEATH, H. 1911. The Solenogastres. Reports on the scientific results of the expedition to the tropical Pacific ... by the “Albatross. ...”” Memoirs of the Museum of Comparative Zoology (Harvard University) 45(1):1-179 + 40 pls. Ivanov, D.I. 1981. [Caudofoveatus tetradens gen. et. sp. n. and diagnosis of taxa in the subclass Caudofoveata (Mollusca, Aplacophora)]. Zoologicheskii Zhurnal (Akad. Nauk SSSR) 60:18-28 {in Russian]. Ivanov, D. I. 1984. [Caudofoveats (Mollusca, Caudofoveata) in Peter the Great Bay]. Pp. 28-41. Jn: A. I. Kafanov (ed.), [Hydrobiological research of bays and inlets of Primorye]. Far East Science Center, USSR Acad. Sci., Vladivostok [in Russian]. KaATHMaAN, R. D., R. O. BRINKHURST, R. E. Woops & S. F. Cross. 1984. Benthic studies in Alice Arm, B.C., following cessation of mine tailings disposal. Canadian Technical Re- port of Hydrography and Ocean Sciences No. 37, 57 pp. A. H. Scheltema et al., 1991 KaTHMaN, R. D., R. O. BRINKHURST, R. E. Woops & D. C. JEFFRIES. 1983. Benthic studies in Alice Arm and Hastings Arm, B.C. in relation to mine tailings dispersal. Canadian Technical Report of Hydrography and Ocean Sciences No. 22, 30 pp. + appendices. SALVINI-PLAWEN, L. v. 1978. The species-problem in Cau- dofoveata (Mollusca). Zoologischer Anzeiger 200:18-26, figs. 1-10. SALVINI-PLAWEN, L. v. 1984. [Comments on Chaetoderma and Crystallophrisson (Mollusca, Caudofoveata]. Zoologicheskii Zhurnal 63:171-175 [in Russian]. SCHELTEMA, A. H. 1972. The radula of the Chaetodermatidae (Mollusca, Aplacophora). Zeitschrift fir Morphologie der Tiere 72:361-370. SCHELTEMA, A. H. 1973. Heart, pericardium, coelomoduct openings, and juvenile gonad in Chaetoderma nitidulum and Falcidens caudatus (Mollusca, Aplacophora). Zeitschrift fur Morphologie der Tiere 76:97-107. SCHELTEMA, A. H. 1976. Two new species of Chaetoderma from off west Africa (Aplacophora, Chaetodermatidae). Journal of Molluscan Studies 42:223-234. Page 213 SCHELTMA, A. H. 1989. Australian aplacophoran molluscs: I. Chaetodermomorpha from Bass Strait and the continental slope off southeastern Australia. Records of the Australian Museum 41:43-62. ScHWABL, M. 1963. Solenogaster mollusks from southern Cal- ifornia. Pacific Science 17:261-281. Stork, H. A. 1941. Solenogastren der Siboga-Expedition. Si- boga Expeditie 47b:45-70. [U.S.] BUREAU OF FISHERIES. 1906. Dredging and hydrographic records of the U.S. Fisheries Steamer Albatross for 1904 and 1905. Report of the Commissioner of Fisheries for the Fiscal Year 1905 and Special Papers, Bureau of Fisheries Docu- ment No. 604, 80 pp. U.S. COMMISSION OF FISH AND FISHERIES. 1905. Records of dredging and other collecting and hydrographic stations of the Fisheries Steamer Albatross in 1903. Report of the Com- missioner of Fisheries for the year ending June 30, 1903, 29:123-138. The Veliger 34(2):214-221 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Mollusca of Assateague Island, Maryland and Virginia: A Reexamination after Seventy-Five Years by CLEMENT L. COUNTS, III anp TERRY L. BASHORE Coastal Ecology Research Laboratory, Department of Natural Sciences, University of Maryland Eastern Shore, Princess Anne, Maryland 21853, USA Abstract. A comparison was undertaken of molluscan collections in waters surrounding Assateague Island by J. Henderson and P. Bartsch in 1913 and collections by the present authors during 1988- 1989. In 1914, Henderson and Bartsch reported 38 species of bivalves and 44 species of gastropods as compared with 33 species of bivalves and 40 species of gastropods in the present study. Of 82 species reported by Henderson and Bartsch, 50 are now present in Assateague waters plus an additional 25 species, including one species of Polyplacophora, and the cephalopod Loligo pealeiz, that were not reported in their study. Of 11 gastropod taxa erected by Henderson and Bartsch for specimens collected in Chincoteague Bay, two species have been synonymized and the remaining nine species were not found in the present study. Stabilization of an inlet with a stone jetty after the hurricane of 1933 produced a salinity change in the bays of Assateague Island that may be responsible for some changes observed in the molluscan fauna. INTRODUCTION Studies of the Mollusca of the waters surrounding Assa- teague Island, Maryland and Virginia, have ranged from simple species lists (CARSON, 1945; BENNET, 1969) to re- ports on biology (SIELING, 1955b; WELLS, 1957; BOYNTON, 1970), diseases (SIELING, 1952; TAYLOR, 1958) and pests and their control (SIELING, 1955a, c, 1956, 1960; GRIFFITH & CASTAGNA, 1962). Although mollusks of the area have been detailed in general identification guides to the Atlantic fauna (Morris, 1973; ABBOTT, 1974, 1986; EMERSON & JACOBSON, 1976; REHDER, 1981), the only critical list of mollusks from these waters was produced by HENDERSON & BARTSCH (1914). HENDERSON & BARTSCH (1914) reported 38 species of bivalves and 44 species of gastropods from Chincoteague Island, Virginia, from collections made during a week in the summer of 1913 in either Chincoteague Bay or the Atlantic waters just offshore. Eleven of the gastropods reported in their study were described as new species. Since their field study and report, the hydrography of waters surrounding Assateague Island has changed. This change is the result of the opening of Ocean City Inlet during the hurricane of 1933, and its subsequent stabilization by the U.S. Army Corps of Engineers (DOLAN et al., 1977). This event changed a positive estuary, at the time of Henderson and Bartsch’s collections, extending from Assawoman Bay to Chincoteague Bay, into a reverse estuary now emptying at both Chincoteague Bay and Ocean City Inlet. That event had a significant impact on salinity and circulation in the bays behind Assateague Island. The present study was undertaken to determine changes in the molluscan fauna of waters surrounding Assateague Island; Maryland and Virginia, 75 years after the study of HENDERSON & BARTSCH (1914). METHODS The Study Site Assateague Island is a barrier island system approxi- mately 58 km in length and averaging 0.8 km in width (Biccs, 1970) (Figure 1). The island is bounded on the north by Ocean City Inlet and on the south by Chinco- teague Inlet, on the east by the Atlantic Ocean and on the west by the northern Sinepuxent Bay and southern Chin- coteague Bay. The average depth of Sinepuxent Bay ranges from 1 to 1.5 m, with a 2-m channel, and deepens to 5-6 m at Ocean City Inlet. The maximum width of Chinco- teague Bay is 11.6 km and the entire back bay system has an area of 428.9 km? (BiGGs, 1970). The depth of Chin- coteague Bay ranges from 1 to 3 m, deepening to 28 m at C. L. Counts, III & T. L. Bashore, 1991 Maryland Virginia << Chincoteague Inlet Page 215 Ocean City Inlet let Shaliows North Beach Intet Sinepuxent Iniet S—Fox Hill & Winter Quarter inlets Figure 1 Assateague Island, Maryland and Virginia, showing general geography of the island and noting the locations of inlets cut through the island by storms (see Table 2). Chincoteague Inlet. The southern end of the island con- tains Tom’s Cove, formed by a westward bending sand spit (Fishing Point) and the main body of the island. The average depth of Tom’s Cove is 1 m. SIELING (1954a) described the physical characteristics of the waters surrounding Assateague Island. In summer months, water temperatures are cooler at the inlets and warmer in the shallow bays. In the winter, this pattern is reversed and occasionally the bays will freeze over with ice. In summer, salinities decrease toward the inlets where tidal surge mixes seawater with high salinity bay water. The salinity pattern reverses during the winter and spring months. Summer salinity patterns result from a net water loss from evaporation that is made up by tidal inflow and a minimal freshwater inflow from the freshwater streams of the mainland (PELLENBARG & BiGGs, 1970). Summer 1989 was characterized by higher than usual rainfall and salinities ranged from 27 to 29 ppt in Sinepuxent Bay and from 24 to 25 ppt in Chincoteague Bay, the highest salin- ities being measured near the inlets. Tidal amplitudes are not dramatic, being approximately 1 m at the inlets and 0.33 m in the bays. The currents of Chincoteague and Page 216 Table 1 Molluscan taxa found in waters surrounding Assateague Island during the present study and compared with that of HENDERSON & BARTSCH (1914) [+ = Present, — = Absent]. Two gastropod species described by HENDERSON & BARTSCH (1914) (Cerithiopsis virginica [=Cerithiopsis greeni| and Epitonium virginicum [=Epitonium multistria- tum]) are not listed because of subsequent synonymy. Hender- Pre- son sent and Taxa study Bartsch Bivalvia Abra aequalis (Say, 1822) Anadara ovalis (Bruguiére, 1789) Anadara transversa (Say, 1822) Anomia simplex Orbigny, 1842 Argopecten gibbus (Linné, 1758) Argopecten irradians irradians (Lamarck, 1819) Argopecten irradians f. concentricus (Say, 1822) Astarte castanea (Say, 1822) Barnea truncata (Say, 1822) Chione cancellata (Linné, 1767) Corbula contracta Say, 1822 Crassinella lunulata (Conrad, 1834) Crassostrea virginica (Gmelin, 1791) Cyclocardia borealis (Conrad, 1831) Cyrtopleura costata (Linné, 1758) Dinocardium robustum (Lightfoot, 1786) Divaricella quadrisulcata (Orbigny, 1842) Donax variabilis Say, 1822 Ensis directus Conrad, 1843 Ensis minor Dall, 1900 Gemma gemma (Totten, 1834) Guekensia demissa (Dillwyn, 1817) Ischadium recurvum (Rafinesque, 1820) Laevicardium mortoni (Conrad, 1830) Linga pennsylvanica (Linné, 1758) Lyonsia hyalina Conrad, 1831 Macoma balthica (Linné, 1758) Macoma tenta (Say, 1834) Mercenaria mercenaria (Linné, 1758) Mulinia lateralis (Say, 1822) Mya arenaria Linné, 1758 Mytilus edulis Linné, 1758 Noetia ponderosa (Say, 1822) Nucula proxima Say, 1822 Nuculana acuta (Conrad, 1831) Petricola pholadiformis (Lamarck, 1818) Pitar morrhuanus (Linsley, 1848) Pleuromeris tridentata (Say, 1826) Raeta plicatella (Lamarck, 1818) Solemya velum Say, 1822 Sole. viridis Say, 1821 Spisula solidissima (Dillwyn, 1817) Spisula solidissima similis (Say, 1822) Tagelus divisus (Spengler, 1794) Tagelus plebewus (Lightfoot, 1786) Tellina agilis Stimpson, 1857 Yoldia limatula (Say, 1831) ++4+4 1 +++4+ + | b+) ++tt+t¢¢4¢4¢ 141 P+++ 0 ttt] ¢4+4+4¢ 1 +444 b+++tHt 1411 + l b+++tttt¢4¢¢4¢4+14¢4+41 l+++4++ 1 +++4+4+4 1 eae orl The Veliger, Vol. 34, No. 2 Table 1 Continued Hender- Pre- son sent and Taxa study Bartsch Gastropoda Acanthodoris pilosa (Muller, 1776) Acteocina canaliculata (Say, 1822) Anachis avara (Say, 1822) Boonea impressa (Say, 1821) Buccinum undatum Linné, 1758 Busycon canaliculatum (Linné, 1758) Busycon carica (Gmelin, 1791) Busycon sinestrum (Hollister, 1958) Cerithiopsis greeni (C. B. Adams, 1839) Clathurella jewetti Stearns Cratena pilata (‘Gould’ Binney, 1870) Crepidula convexa Say, 1822 Crepidula fornicata (Linné, 1758) Crepidula plana Say, 1822 Creseis virgula (Rang, 1828) Crucibulum striatum Say, 1824 Cylichnella bidentata (Orbigny, 1841) Diastoma alternatum virginicum Henderson & Bartsch, 1914 Diodora cayenensis (Lamarck, 1822) Epitonium angulatum (Say, 1830) Epitonium humphreysi (Kiener, 1838) Epitonium multistriatum (Say, 1826) Epitonium rupicola (Kurtz, 1860) Eupleura caudata (Say, 1822) Ilyanassa obsoleta (Say, 1822) Inodrillia dalli (Verrill & Smith, 1882) Kurtziella cerina (Kurtz & Stimpson, 1851) Littorina irrorata (Say, 1822) Littorina littorea (Linné, 1758) Littorina saxatilis (Olivi, 1792) Lunatia heros (Say, 1822) Lunatia pallida (Broderip & Sowerby, 1829) Lunatia triseriata (Broderip & Sowerby, 1829) Mangilia sp. Marginella roscida Redfield, 1860 Melampus bidentatus Say, 1822 Melanella intermedia (Cantraine, 1835) Mitrella lunata (Say, 1826) Nassarius trivittatus (Say, 1826) Nassarius vibex (Say, 1822) Odostomia pocahontasae Henderson & Bartsch, 1914 Odostomia toyatani Henderson & Bartsch, 1914 Odostomia virginica Henderson & Bartsch, 1914 Olivella mutica (Say, 1822) Polinices duplicatus (Say, 1822) Sinum perspectivum (Say, 1831) Terebra concava Say, 1827 Terebra dislocata (Say, 1822) Thais haemastoma f. floridana (Conrad, 1837) b++ttti +44 +++++44 i ++ttet¢t+e+¢¢test | | ++H+4+4 | +1 +441 + betel t+t+et 1 +44 Jae ee + t++4++ 1441 4+ + + t++tt 14 C. L. Counts, II] & T. L. Bashore, 1991 Table 1 Continued Hender- Pre- son sent and Taxa study Bartsch Triphora nigrocincta (C. B. Adams, 1839) = + Triphora pyrrha Henderson & Bartsch, 1914 = + Turbonilla pocahontasae Henderson & Bartsch, 1914 — + Turbonilla powhatani Henderson & Bartsch, 1914 — = Turbonilla toyatani Henderson & Bartsch, 1914 — + Turbonilla virginica Henderson & Bartsch, 1914 — + Urosalpinx cinerea (Say, 1822) oF + Cephalopoda Loligo pealen Lesueur, 1821 + — Polyplacophora Chaetopleura apicalata (Say, 1830) + = Sinepuxent bays are mostly independent of the non-tidal oceanic currents and water flows away from the inlets at Ocean City and at Chincoteague as the tides rise (PEL- LENBARG & BiGGs, 1970). Bay water circulation is such that the total water movement of the bays allows a daily water exchange of approximately 7.5% from outside sources (PRITCHARD, 1960). PELLENBARG & BiGGs (1970) report the bays to be essentially stagnant and intensely heated and stratified during summer months. SIELING (1954a) noted that currents throughout the bays, although of no great magnitude, may have some influence on shellfish larval distribution. The Atlantic coastal waters of Assateague Island are shallow and PELLENBARG & Biccs (1970) noted that they become rapidly stratified by mid-April and that there is little mixing between thermally stratified waters. Summer surface currents are generally onshore and the entire water mass has a northerly drift, perhaps due to the nearby Gulf Stream (PELLENBARG & Biccs, 1970). Mollusks are distributed over the North American At- lantic Coast in distinct provinces that are defined by the identity of the species found in a given area. One province is different from another when 50% of the species found in province A cannot be found in province B (PIELOU, 1979). Assateague Island is located in the Boreal Mollus- can Province, which is characterized by low diversity and high population densities. The island is located just to the north (approximately 80 km) of the Virginian Subprovince (a subdivision of the Carolinian Province that includes the coast of Virginia to Florida and the Gulf states). Because the borders between provinces are not sharp, some faunal elements of the Virginian Subprovince are found in As- sateague’s waters or cast ashore as drift shells. Page 217 Collections Molluscan collections were made monthly between April 1988 and August 1989. Collection methods included hand collecting, dredging, and bottom grab samples in all waters surrounding the island and at intertidal habitats such as the Ocean City Inlet jetty in the north and pier structures in the south. All materials collected were returned to the laboratory and identifications made using standard ref- erences to the Atlantic Coast fauna (Morris, 1973; ABBOTT, 1974, 1986; EMERSON & JACOBSON, 1976; REHDER, 1981). In those cases where taxonomic differences existed for a species, the taxonomy of ABBOTT (1974) was used. Ad- ditional records for the Chincoteague Bay area were pro- vided by Dr. Robert S. Prezant, Indiana University of Pennsylvania, and Dr. Steve Rebach, University of Mary- land Eastern Shore. RESULTS The present study revealed the presence of 75 species of Mollusca in the waters surrounding Assateague Island (Table 1). HENDERSON & BARTSCH (1914) reported 82 species of which 50 were found in the present study. Al- though this appears to represent a net decline in molluscan diversity, the present study revealed the presence of 25 species not reported by Henderson and Bartsch. Thirty-eight species of bivalves were reported by HENDERSON & BARTSCH (1914) while 33 species were found during the present study (Table 1). Species reported by them but not found during the present study include Abra aequalis, Corbula contracta, Dinocardium robustum (al- though they note that this may have been a drift shell), Ensis minor, Laevicardium mortoni, Linga pennsylvanica, Lyonsia hyalina, Macoma tenta, Nucula proxima, Nuculana acuta, Pitar morrhuanus, Pleuromeris tridentata, Spisula so- lidissima similis, Tagelus divisus, and Yoldia limatula. Bi- valves found during the present study but not reported by HENDERSON & BarRTSCH (1914) include Argopecten irra- dians irradians, Argopecten irradians forma concentricus, Barnea truncata, Ensis directus, Gemma gemma, Geukensia demissa, Ischadium recuruum, Macoma balthica, Solemya ve- lum, and Solen viridis. HENDERSON & BARTSCH (1914) reported 44 species of gastropods from Assateague waters while the present study reveals the presence of 40 (Table 1). Species reported by Henderson and Bartsch but not found during the present study include Boonea impressa, Cerithiopsis greeni, Clathu- rella jewetti, Diastoma alternatum virginicum, Lunatia pal- lida, Mangilla sp., Marginella roscida, Odostomia pocahon- tasae, Odostomia toyatani, Odostomia virginica, Terebra convaca, Triphora nigrocincta, Triphora phyrra, Turbonilla pocahontasae, Turbonilla powhatani, Turbonilla toyatani, and Turbonilla virginica. Gastropod species found during the present study but not found by Henderson and Bartsch were Acanthodoris pilosa, Buccinum undatum, Cratena pi- lata, Creseis virgula, Crucibulum striatum, Epitonium an- gulatum, Inodrillia dalli, Littorina littorea, Littorina saxatilis, Page 218 Lunatia triseriata, Melampus bidentatus, Olivella mutica, and Thais haemastoma floridana. The present study also re- vealed the presence of the cephalopod Loligo pealeu and the polyplacophoran Chaetopleura apiculata. No mollusks from these classes were reported by HENDERSON & BARTSCH (1914). DISCUSSION The collection methods of HENDERSON & BARTSCH (1914) cannot be exactly duplicated because they were inade- quately described. However, several factors may account for changes in the molluscan fauna at Assateague Island from 1913 to 1989. The simplest explanation is that mol- luscan species were overlooked during the original study by HENDERSON & BARTSCH (1914): because their collec- tions were made over the course of a few days in July 1913, it is not unreasonable that some species escaped notice. This is especially so of the pteropod Cresevs virgula, which ranges from 40°N to 40°S (ABBoTT, 1974). The pelagic nature of this mollusk is such that it has been collected at Assateague Island only once in the last five years. Although the squid Loligo pealen is not pelagic, encounters during just a few days of collecting would be unlikely. The nudibranch Acanthodoris pilosa is found with the sponge Clione caelata. Small infaunal species such as Gemma gemma could easily be missed without the proper collecting equipment. We were unable to locate specimens of Macoma tenta or Tagelus divisus though these species were collected in the late 1960s (DROBECK et al., 1970). Some species now found are newly introduced into As- sateague waters. 7hais haemastoma forma floridana was not present in Chincoteague Bay at the time of Henderson and Bartsch’s collections. This gastropod, an important predator of barnacles, oysters, mussels, and other bivalves, is usually found from North Carolina south to Florida, the Caribbean, and Brazil (ABBOTT, 1974). SIELING (1960) first reported this species in Chincoteague Bay and noted that it was probably imported with transplanted oysters. With the decline of oyster populations, it is now rare. The identification of scallop species has also been in flux since . HENDERSON & BARTSCH (1914) made their collections. Nevertheless, Argopecten irradians irradians was not taken in Chincoteague Bay until 1960 and its distribution was directly correlated with the invasion of the grass Zostera marina (BOYNTON, 1970). The two littorinids found during the present study, Lt- torina littorea and Littorina saxatilis, are also notable. CLARKE (1971) and ABBotT (1974) reported the range of L. littorea as Labrador to Maryland. The species is found along the coasts of Delaware and Maryland only on rock jetties or wooaen groins. There has been some debate as to whether this species was introduced into North American waters from Europe (CLARKE, 1971) but archaeological evidence from Indian and Norse sites in Canada indicates that the species has been in North America since the 13th century (CLARKE & ERSKINE, 1961; CLARKE, 1963, 1971; MEDCOF The Veliger, Vol. 34, No. 2 et al., 1965) or as early as 1000 AD (CLaRKE, 1971). It is believed the species was restricted to Canadian waters and was transported south by ships sometime in the 1840s to 1880s or that unusually high air-sea temperatures al- lowed natural penetration of southern waters in the 1870s (CLARKE, 1971). Its southward spread is believed to be limited by higher water temperatures, but the sandy beach- es of the southern coastal states may be more limiting than water temperature. Other factors possibly explaining observed faunal dif- ferences are changes in back bay circulation, and therefore also in salinity, that resulted from the opening of the Ocean City Inlet. Historically, Assateague Island was usually continuous with Fenwick Island, Delaware and Maryland (KRAFT et al., 1973; DOLAN et al., 1977; LEATHERMAN, 1988). However, several transient inlets have opened the back bays of Assateague Island to the Atlantic, and the positions of these inlets have been noted over the past 250 years (Figure 1, Table 2). The hurricane of 1933 resulted in the opening of the Ocean City Inlet, which was sub- sequently stabilized by a jetty constructed by the U.S. Army Corps of Engineers in 1935 (LEATHERMAN, 1988). Until this event, the back bay system behind Fenwick- Assateague was essentially a positive estuary emptying into Chincoteague Bay with waters of relatively low salinities. However, the stabilization of the Ocean City Inlet has resulted in a permanent alteration of back bay circulation. Marine molluscan habitats can be defined by salinity flux, and while molluscs may survive a wide range of salinity concentrations, specific behavioral, reproductive, and physiological activities may be dependent upon a much narrower range (DODGSON, 1928; SCHLIEPER, 1953; VERNBERG ef al., 1963; BAYNE, 1965; CASTAGNA & CHANLEY, 1973). Crassostrea virginica provides a well stud- ied example. The overall salinity tolerance of this bivalve has been variously reported as 0-42.5 ppt (INGLE & Dawson, 1951) and 5-30 ppt (GALTSOFF, 1964). How- ever, the absolute minimum for survival has been reported as 0.2-3.6 ppt (BUTLER, 1952) and 4-5 ppt (RYDER, 1885; ARNOLD, 1868a, b; BELDING, 1912; LOOSANOFF, 1932). The salinity range for optimal survival was reported as 14.1-22.2 ppt (Moore, 1900) but others state salinities greater than 7.5 ppt are the minimum for normal survival (LoosANoFF, 1952; CHANLEY, 1958). While these salinity ranges imply wide latitude for the survival of individual oysters, other studies indicate that a narrower salinity range must exist for successful completion of certain life-cycle stages and physiological activities. FINGERMAN (1959) re- ported normal ciliary activity at 5-35 ppt and VERNBERG et al. (1963) reported a decrease in ciliary activity at 4 ppt. This agrees with studies that found salinities must be greater than 5 ppt for normal feeding activity (LOOSANOFF, 1952). Normal growth has been reported from greater than 10 ppt (LoosANorFF, 1952) to an optimum of greater than 20 ppt (MEDcoF & NEEDLER, 1941; MEDcor, 1944) and CHANLEY (1958) found a range of 12.5-25 ppt as the optimum for growth of newly metamorphosed larvae. The C. L. Counts, III & T. L. Bashore, 1991 minimum salinity for gametogenesis has been reported as 6 ppt (BUTLER, 1952) and 7.5 ppt (LOOSANoFF, 1952). Egg cleavage and development have been reported within ranges of 7.5 to 40.1 ppt (AMEmMIYA, 1926; Davis, 1958) with optima at 10-22.5 ppt (Davis, 1958) and 19.3-35 ppt (AMEmMIyA, 1926). Davis (1958) also reported a 10 ppt minimum for metamorphosis while PRYTHERCH (1934) reported the range over which metamorphosis will occur as 5.6-32.2 ppt. AMEMIYA (1926) reported normal larval development to occur between 14 and 39 ppt with an optimum of 25-29 ppt. Thus, even though a mollusk is found in waters whose salinity is within the range for survival, the salinity may be outside the range for other vital functions that ensure survival of the population. Before the opening of the Ocean City Inlet, salinity in Chincoteague Bay was low enough that Crassostrea vir- ginica existed there essentially free of parasitic diseases and was not molested by such predators as Eupleura cau- data or Urosalpinx cinerea (BOYNTON, 1970). SIELING (1961) reports that after stabilization of the inlet, oyster mortal- ities ranging from 50 to 100% occurred throughout Chin- coteague Bay, with a high percentage of the affected oysters being infected by Minchinia nelsoni (MSX). Further, sa- linity concentrations above 15 ppt, while not directly af- fecting C. virginica, allowed optimum conditions for the survival of EF. caudata and U. cinerea (DAIBER et al., 1976). Of the species now at Assateague Island but absent at the time of Henderson and Bartsch’s collections, only the presence of Ensvis directus, Solemya velum, and Solen viridis could be explained on the basis of higher salinities (CASTAGNA & CHANLEY, 1973). While salinity may be a prime factor in community composition change, its effects on individual species may not account for the species’ sur- vival at Assateague (DAVIES, 1972). Few of the species found by HENDERSON & BARTSCH (1914) should have experienced a fatal shift in salinity with the stabilization of the Ocean City Inlet (CASTAGNA & CHANLEY, 1973). While low salinities have been found in Chincoteague Bay since 1935 (SIELING, 1958), salinity is now, on the average, higher than in the period before stabilization of the Ocean City Inlet. However, the higher salinities of Chincoteague and Sinepuxent bays are still within the limits of tolerance for such species as Ensis minor, Laevicardium mortoni, Lyonsia hyalina, Nucula proxima, Pleuromeris tridentata, Tagelus divisus, and Yoldia limulata (CASTAGNA & CHANLEY, 1973). Further, no significant shift in bivalve feeding types has been observed. Using the bivalve feeding scheme of Mor Ton (1983), the proportions of suspension- and de- posit-feeding bivalves have remained constant despite changes in species composition. The mollusks of Assa- teague have experienced population damage from hurri- canes (SIELING, 1954b), invasions of several predators (SIE- LING, 1955a, b, 1960), and introductions of diseases (TAYLOR, 1958). The shift in molluscan community struc- ture may be a combination of physiological effects of changes in hydrodynamics and salinity or changes in sediment com- position (DAVIES, 1972). Page 219 Table 2 Location and dates of inlets of Assateague Island during the past 250 yr. See Figure 1 for locations. R = Recurring inlet. (After DOLAN et al., 1977.) Year(s) Location 1700s North Beach Inlet Sinepuxent Inlet (R) Green Run Inlet (R) 1766 Slough Inlet 1800s Sinepuxent Inlet (R) Fox Hill Inlet Winter Quarter Inlet Green Run Inlet (R) 1841 North Beach Inlet (R) 1850s Pope Island Inlet (R) 1870s North Beach Inlet (R) Pope Island Inlet (R) 1900s Sinepuxent Inlet (R) 1920 Sandy Point Inlet (R) 1933 Ocean City Inlet Inlet Shallows (R) 1962 Sandy Point Inlet (R) Eleven species of gastropods have been described only from the waters of Chincoteague. These are Cerithiopsis virginica, Diastoma virginica, Epitonium virginicum, Odosto- mia pocahontasae, Odostomia toyatani, Odostomia virginica, Triphora pyrrha, Turbonilla pocahontasae, Turbonilla pow- hatam, Turbonilla toyatani, and Turbonilla virginica. All of these species were described by HENDERSON & BARTSCH (1914) from waters off Chincoteague Island, Virginia. Sev- eral of these species have since been synonymized. Cer- thiopsis virginica and Epitonium virginicum are now rec- ognized as junior synonyms of Cerithiopsis greeni and Epitonium multistriatum, respectively. Triphoris pyrrha has been placed in the genus 777phora and is now recognized as Triphora pyrrha. Diastoma virginica is now recognized as a subspecies of Diastoma alternatum and is thus named Diastoma alternatum virginicum. Except for these synon- ymized taxa, none of the species described by HENDERSON & BartscH (1914) was found during our collections. Odostomids are sometime ectoparasites of oysters, mussels, and slipper shells and they feed by penetrating the tissues of the host animals and sucking their body fluids. Because of their restricted habitat, quasi-parasitic life cycle, and the decline of their principal host (oysters), they may in fact be extinct. They are not presently on the Federal List of Threatened and Endangered Species, but they are cer- tainly candidates. However, before recommendation for protected status, a detailed survey of oyster and mussel beds should be conducted. ACKNOWLEDGMENTS We would like to thank Larry Points, Chief of Interpre- tation, Assateague Island National Seashore, for his sup- Page 220 The Veliger, Vol. 34, No. 2 port of this project. We would also like to thank Jack Kumer, Resource Management Staff, and UMES students C. E. Furbish and John Williams for collecting some of the species reported in this paper. We also thank Michael Castagna, Virginia Institute of Marine Science, Wacha- preague, for his useful discussion of our results. Drs. Rob- ert S. Prezant and Steve Rebach kindly provided data from their respective collections and class project reports. Dr. Prezant also reviewed an early draft of the manuscript and provided helpful comments and suggestions. This re- search was supported by the Eastern National Parks and Monuments Association and Assateague Island National Seashore. LITERATURE CITED ABBOTT, R. T. 1974. American Seashells. 2nd ed. Van Nos- trand Reinhold: New York. vi + 663 pp. ABBOTT, R. T. 1986. Seashells of North America. Rev. ed. Golden Press: New York. 280 pp. AMEMIYA, I. 1926. Notes on experiments on the early devel- opmental stages of the Portuguese, American and English native oysters with special references to the effect of varying salinity. Journal of the Marine Biological Association of the United Kingdom 14:161-175. ARNOLD, T. 1868a. Oysters in brackish waters. Quarterly Journal of Science 19:237. ARNOLD, T. 1868b. Oysters in brackish waters. Quarterly Journal of Science 21:15-19. BAYNE, B. L. 1965. Growth and delay of metamorphosis of the larvae of Mytilus edulis (L.). Ophelia 2:1-47. BELDING, D. L. 1912. A report upon the quahog and oyster fisheries of Massachusetts. Department of Conservation, Commonwealth of Massachusetts (Boston). 134 pp. BENNET, J. 1969. A checklist of the most common invertebrates of Chincoteague Bay. Resources Management Plan, Assa- teague Island National Seashore. U.S. Department of the Interior, National Park Service. 10 pp. Biccs, R. B. 1970. The origin and geological history of As- sateague Island, Maryland and Virginia. Jn: Assateague Ecological Studies, Part I. Environmental Information. Nat- ural Resources Institute, University of Maryland (College Park), Contribution No. 446:9-41. Boynton, W. J. 1970. The commercial fisheries of Chinco- teague Bay—past, present and future. Jn: Assateague Eco- logical Studies, Part I. Environmental Information. Natural Resources Institute, University of Maryland (College Park), Contribution No. 446:357-388. BUTLER, P. A. 1952. Effects of floodwaters on oysters in Mis- sissippi Sound in 1950. U.S. Fish and Wildlife Service, Re- search Report 31:1-20. Carson, R. L. 1945. Fish and shell fish of the middle Atlantic. U.S. Department of the Interior: Washington, D.C. CasTAGna, M. & P. CHANLEY. 1973. Salinity tolerance of some marine bivalves from inshore and estuarine environments in Virginia on the western mid-Atlantic coast. Malacologia 12(1):47-96. CHANLEY, P. 1958. Survival of some juvenile bivalves in water of low salinity. Proceedings of the National Shellfisheries Association 48:52-65. CLARKE, A. H. 1963. Supplementary notes on pre-Columbian Littorina littorea in Nova Scotia. The Nautilus 77:8-11. CLARKE, A. H. 1971. Littorina littorea, native or introduced? The Biologist 53(3):160-162. CuLaRKE, A. H. & J.S. ERSKINE. 1961. Pre-Columbian Littorina littorea in Nova Scotia. Science 134:393-394. DalBeER, F. C., L. L. THORNTON, K. A. BOLSTER, T. G. Camp- BELL, O. W. CRICHTON, G. L. Esposiro, D. R. JONES & J. M. TyRAWSKI. 1976. An atlas of Delaware’s wetlands and estuarine resources. Delaware Coastal Management Pro- gram (Dover), Technical Report No. 2:xii + 528 pp. Davigs, T. T. 1972. Effect of environmental gradients in the Rappahannock River estuary on the molluscan fauna. In: B. W. Nelson (ed.), Environmental Framework of Coastal Plain Estuaries. The Geological Society of America, Inc., Memoir 133:263-290. Davis, H. C. 1958. Survival and growth of clam and oyster larvae at different slainities. Biological Bulletin 114:296- 307. Dopcson, R. W. 1928. Report of mussel purification. Great Britain, Ministry of Agriculture Fisheries Investigations, Series 2, 10:1-498. Do.an, R., B. HAYDEN & J. HEYwoop. 1977. Atlas of En- vironmental Dynamics, Assateague Island National Sea- shore. U.S. Department of the Interior, National Park Ser- vice (Washington, D.C.), Natural Resources Report No. 10. 40 pp. DRoBEcK, K., H. Hipu, J. M. ODELL & W. BoyNToNn. 1970. Chincoteague and Sinepuxent bay benthos. Jn: Assateague Ecological Studies, Part I. Environmental Information. Nat- ural Resources Institute, University of Maryland (College Park), Contribution No. 446:175-241. EMERSON, W. K. & M. K. JAcoBSON. 1976. The American Museum of Natural History Guide to Shells: Land, Fresh- water, and Marine, from Nova Scotia to Florida. Alfred A Knopf: New York. 482 + xviii pp. FINGERMAN, N. 1959. Effects of temperature and salinity on ciliary activity in the oyster, Crassostrea virginica. Commis- sion on Fisheries Review 21(2):10-11. GALTSOFF, P. S. 1964. The American oyster, Crassostrea vir- ginica Gmelin. Fisheries Bulletin 64:1-480. GRIFFITH, G. W. & M. CastTaGNa. 1962. Sexual dimorphism in oyster drill of Chincoteague Bay, Md.-Va. Chesapeake Science 3(3):215-217. HENDERSON. J. B. & P. BARTSCH. 1914. Littoral marine mol- lusks of Chincoteague Island, Virginia. Proceedings of the United States National Museum 47:411-421. INGLE, R. M. & C. E. Dawson. 1951. Variations in salinity and its relation to the Florida oyster. Salinity variations in Apalachicola Bay, Florida. Proceedings of the Gulf and Ca- ribbean Fisheries Institute 3:35-42. KraFT, J. C., R. B. Biccs & S. D. HALsEy. 1973. Morphology and vertical sedimentary sequence models in Holocene trans- gressive barrier systems. Pp. 321-354. In: D. R. Coates (ed.), Coastal Geomorphology. State University of New York (Binghampton), Publications in Geomorphology. LEATHERMAN, S. P. 1988. Barrier Island Handbook. 3rd ed. Coastal Publications Series, Laboratory for Coastal Re- search, University of Maryland (College Park). iv + 92 pp. LoosanoFF, V. L. 1932. Observations on propagation of oysters in James and Corrotoman rivers and the seaside of Virginia. Virginia Commission on Fisheries (Newport News). 46 pp. LoosanorF, V. L. 1952. Behavior of oysters in water of low salinities. Proceedings of the National Shellfisheries Asso- ciation 43:135-151. Mepcor, J. C. 1944. How relaying and transferring at dif- ferent seasons affects the fatness of oysters. Fisheries Re- search Board of Canada. Progress Report of Atlantic Coast Stations 35:11-14. MepcorF, J. C., A. H. CLARKE & J.S. ERSKINE. 1965. Ancient C. L. Counts, HI & T. L. Bashore, 1991 Canadian east-coast oyster and quahog shells. Journal of the Fisheries Research Board of Canada 22:631-634. Mepcor, J. C. & A. W. H. NEEDLER. 1941. The influence of temperature and salinity on the condition of oysters (Ostrea virginica). Journal of the Fisheries Research Board of Can- ada 5:253-257. Moore, H. F. 1900. An inquiry into the feasibility of intro- ducing useful marine animals into the waters of the Great Salt Lake. Report of the U.S. Commission for Fisheries 25: 229-250. Morris, P. A. 1973. A Field Guide to Shells of the Atlantic and Gulf Coasts and the West Indies. 3rd ed. Houghton Mifflin Company: Boston. xxviii + 330 pp. Morton, B. 1983. Feeding and digestion in Bivalvia. Pp. 65- 147. In: A. S. M. Saleuddin, A. S. M. & K. M. Wilbur (eds.), The Mollusca. Vol. 5, Physiology, Part 2. Academic Press: Orlando, FL. PELLENBARG, R. & R. B. Biccs. 1970. Background environ- mental data on Assateague and surrounding areas. Jn: As- sateague Ecological Studies, Part I. Environmental Infor- mation. Natural Resources Institute, University of Maryland (College Park), Contribution No. 446:42-69. PIELOu, E. C. 1979. Biogeography. John Wiley & Sons: New York. ix + 351 pp. PRITCHARD, D. W. 1960. Salt balance and exchange rate for Chincoteague Bay. Chesapeake Science 1(1):48-57. PRYTHERCH, H. F. 1934. The role of copper in the setting, metamorphosis, and distribution of the American oyster, Os- trea virginica. Ecological Monographs 4:47-107. ReEHDER, H. A. 1981. The Audubon Society Field Guide to North American Seashells. Alfred A. Knopf: New York. 894 PP- RypDER, J. A. 1885. New system of oyster culture. Science 6: 465-467. SCHLIEPER, C. 1953. Physiological adjustment of tissue of Myti- lus from different salinities. Naturwissenschaften 40:538—- 569), Page 221 SIELING, F. W. 1952. Preliminary report on the Chincoteague Bay survey. Proceedings of the National Shellfisheries As- sociation 1952:194-197. SIELING, F. W. 1954a. Report on certain phases of the Chin- coteague Bay investigations. Proceedings of the National Shellfisheries Association 45:212-216. SIELING, F.W. 1954b. Hurricane damage oyster and clam areas in Chincoteague Bay. Maryland Tidewater News 11:2-3. SIELING, F.W. 1955a. Marine fouling pests numerous in Chin- coteague Bay. Maryland Tidewater News 11:1. SIELING, F. W. 1955b. Oyster drill damage heavy in Chinco- teague Bay. Maryland Tidewater News 11:1, 4. SIELING, F. W. 1955c. Hydrographic study of Chincoteague Bay yields new data. Maryland Tidewater News 11:2, 4. SIELING, F. W. 1956. New fouling organisms appear in Chin- coteague Bay. Maryland Tidewater News 12:4. SIELING, F. W. 1958. Low salinity and unusual biological conditions noted in Chincoteague Bay. Maryland Tidewater News 14:15-16. SIELING, F. W. 1960. A notable range extension of the southern drill, Thais haemastoma floridana, into Chincoteague Bay. Chesapeake Science 1(3-4):212-215. SIELING, F. W. 1961. Oyster mortality in the Chincoteague Bay area, 1961. Maryland Department of Research and Education (Solomons). TAYLOR, W. J. 1958. Notice of the occurrence of green-gilled oysters. American Journal of Science 25:294. VERNBERG, F. J., C. SCHLIEPER & D. SCHNEIDER. 1963. The influence of temperature and salinity on ciliary activity of excised gill tissue of mollusks from North Carolina. Com- parative Biochemistry and Physiology 8:271-285. WELLS, H. W. 1957. Abundance of the hard clam Mercenaria mercenaria in relation to environmental factors. Ecology 38(1): 123-128. The Veliger 34(2):222-228 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 Seasonal Changes in Outer Shell Layer Microstructure of Mytilus edulis in New Jersey, USA by LOWELL W. FRITZ,! LISA M. RAGONE,’? anpD RICHARD A. LUTZ Institute of Marine and Coastal Studies, Cook College, New Jersey Agricultural Experiment Station, Rutgers University, New Brunswick, New Jersey 08903, USA Abstract. Inspring and fall, the outer shell layer of Mytilus edulis specimens collected from populations in New Jersey, USA, was composed of long, slender, evenly shaped prismatic needles deposited at angles of about 30° to the inner shell surface, where they terminated in distinct, chisel-shaped tips. (By definition, the long axis of a prism deposited at an angle of 0° was parallel to the inner shell surface and terminated at the posterior margin; angles increased in a clockwise direction.) Prisms deposited in summer were shorter, more uneven or lenticular in shape, and deposited at angles greater than 30°. Following growth interruptions in summer and winter, a cone-shaped region of such prisms was often formed in which prisms were deposited at angles as great as 140°. The inner surface of portions of the outer shell layer composed of these prisms often had a granular texture in which individual prism tips were indistin- guishable. The outer layer microstructure of M. edulis could provide a record of the relative timing and severity of sublethal disturbances in specified time periods, creating an interpretative tool for ecological and paleoecological studies. INTRODUCTION The blue mussel Myézlus edulis Linné has three primary calcareous layers in its shell: an outer calcitic prismatic layer, an aragonitic myostracal layer to which the mantle is attached, and an inner aragonitic nacreous layer (TAYLOR et al., 1969; CARRIKER, 1978). To date, investigations of seasonal changes in shell microstructure in the species have been limited to analyses of the inner nacreous layer. LUTZ (1976) found that the thickness of nacreous tablets de- creased abruptly in spring in M. edulis from Maine, USA. This abrupt rather than gradual decrease in tablet thick- ness could have been due to anaerobiosis-related shell dis- solution associated with winter and/or gametogenesis (LUTZ & RHOADS, 1980). However, thinner tablets could also have resulted from faster rates of nacre deposition as water ‘To whom reprint requests should be sent! NMFS/REFM, Alaska Fisheries Science Center, 7600 Sand Point Way NE, Seattle, Washington 98115. ’ Present address: Virginia Institute of Marine Science, Gloucester Point, Virginia 23062. temperatures increased during this period (WADA, 1961; DIETH, 1985). The outer shell layer of Mytilus edulis is composed of thin calcitic needles between 1 and 3 wm in diameter that are deposited at an angle with respect to the inner surface of the outer layer (TAYLOR e¢ al., 1969). When viewed in polished and etched radial section, the outer shell layer of M. edulis is also divided into a series of microgrowth in- crements (ZOTTOLI & CARRIKER, 1974) that represent al- ternating periods of shell growth (increments) and growth cessation (increment boundaries) (PANNELLA & MaAc- CLINTOCK, 1968; LuTzZ & RHoaDs, 1980). Microgrowth increments in bivalve shells reflect exogenous and/or en- dogenous rhythms that are often highly correlated with cyclic fluctuations in the environment, such as tide, illu- mination, temperature, etc. (see LUTZ & RHOADS, 1980). A microgrowth increment in the outer layer delineates a shell region that was deposited contemporaneously, while a microgrowth increment boundary records the position of the inner surface of the outer layer prior to the deposition of the next microgrowth increment (PANNELLA & MAcCLINTOCK, 1968; LuTz & RHOaDs, 1980). L. W. Fritz et al., 1991 In this paper, we describe in detail changes in the mi- crostructure of the outer shell layer of Mytilus edulis as- sociated with naturally occurring interruptions to growth. The blue mussel is an important species in coastal envi- ronmental impact assessment, as evidenced by its use in the “Mussel Watch” program (NATIONAL ACADEMY OF SCIENCES, 1980; FARRINGTON et al., 1983) and numerous studies of the sublethal effects of pollutants (e.g., SUNILA & LINDSTROM, 1985; AMIARD et al., 1986; STROMGREN et al., 1986). Detailed analyses of blue mussel microstruc- tural shell growth could provide additional information on the timing and sublethal effects of environmental distur- bances. Furthermore, information from such neontological studies could be useful in the examination of fossil mytilid shells in paleoecological investigations. MATERIALS anD METHODS Mussels were collected approximately every two months from three populations in New Jersey. The first was an intertidal population living on a rock jetty in lower Del- aware Bay (38°59'N, 74°58’W). Specimens were collected between 0.5 and 1.0 m above mean low water (MLW). The second population was barely subtidal on the bottom of the Manasquan River (40°06'N, 74°03’W). Water depth at MLW ranged between 0.1 and 0.5 m. The third sampled population, also subtidal, was located in Sandy Hook Bay (40°27'N, 74°03’W) at a MLW depth ranging from 5.2 to 6.4 m. The Delaware Bay population was sampled between April 1986 and May 1987, while the Manasquan River and Sandy Hook populations were sampled between November 1987 and October 1988. Water temperature and salinity at the sampled locations on the days of col- lection ranged from 6.3 to 27.0°C and from 17.1 to 26.0 ppt (parts per thousand), respectively, in Delaware Bay, 10.4 to 24.0°C and 16.9 to 30.0 ppt, respectively, in Man- asquan River, and 7.8 to 20.1°C and 23.7 to 28.2 ppt, respectively, in Sandy Hook Bay. Shell microstructure was studied by light microscopy of acetate peel replicas of polished and etched shell sections and by scanning electron microscopy (SEM) of fractured shell sections. Soft tissues were carefully removed from each specimen, and shells were numbered, thoroughly washed in tap water, and allowed to dry in air overnight. One valve, embedded in liquid casting plastic to prevent breakage, was sectioned from the umbo to the posterior margin using a Raytech 10-inch circular rock saw. Acetate peels were prepared according to the methods outlined in KENNISH e¢ al. (1980). A total of 232 acetate peels of shell sections were analyzed (94 from the Delaware River, 67 from the Manasquan River, and 71 from the Sandy Hook Bay populations). Ranges in shell length and age, respec- tively, of the specimens analyzed from each site were: (1) Delaware Bay, 11.8-43.4 mm, 0-5 yr; (2) Manasquan River, 18.4-66.3 mm, 0-3 yr; and (3) Sandy Hook Bay, 21.9-71.8 mm, 0-3 yr. Shell sections for analysis by SEM were prepared by Page 223 fracturing the shell by hand as close as possible to the anterior-posterior axis (KENNISH et al., 1980). Shell frag- ments were glued to aluminum stubs with cyanoacrylate cement and carbon paint, and coated with Au-Pd in a sputter coater. A total of 40 specimens (21 from the Del- aware River, 9 from the Manasquan River, and 10 from the Sandy Hook populations) were analyzed at 15 and 20 kV accelerating voltages in a Hitachi S-450 scanning elec- tron microscope. Ranges in shell length and age, respec- tively, of the specimens analyzed by SEM from each site were: (1) Delaware Bay, 17.7—40.3 mm, 0-5 yr; (2) Man- asquan River, 18.4—49.5 mm, 0-3 yr; and (3) Sandy Hook Bay, 21.9-70.9 mm,. 0-3 yr. The angle of prism deposition was defined with respect to the inner surface of the outer shell layer. By definition, prisms deposited at an angle of 0° would have their long axes parallel to the inner surface and terminate at the posterior shell margin. Angles of prism deposition in- creased in a clockwise direction and were measured directly off scanning electron micrographs of fractured sections with a protractor. RESULTS anpb DISCUSSION The most obvious seasonal microstructural feature in the outer shell layer of Mytilus edulis was the thick growth- cessation mark (microgrowth increment boundary) re- sulting from a period of dormancy in winter (Figure 1). HILBIsH (1986) found that M. edulis at similar latitudes in eastern Long Island Sound resumed shell growth in February after a dormant period in December and Jan- uary. Winter growth-cessation marks divided the outer layer into annual increments. Annual outer layer micro- structural sequences were similar for mussels collected from all three populations. With increasing age at each site, however, the size of the annual increment declined. There was also a greater tendency for the portion deposited in fall to be absent as age increased beyond 2-3 yr. Con- sequently, shell growth became increasingly limited to spring as individuals aged. The time of formation of por- tions of the outer layer was determined by their proximity to known time-periods in the shell, which included winter marks and the posterior shell margin (date of collection). ‘There were two seasons, summer and late winter, in which terracing of the shell exterior surface was observed. During both seasons, microgrowth increments tended to extend posteriorly only slightly beyond the one most re- cently deposited, yielding a blunt, thick posterior margin. Thus, outer layer shell growth in these periods tended to be directed more toward the shell interior than posteriorly, especially when compared with the outer layer deposited in spring and fall. Specimens collected during spring and fall tended to have a thinner, more pointed posterior shell margin, which is also revealed in the pattern of micro- growth increment boundaries in Figure 1. Terracing of the shell exterior surface tended to be more pronounced in mussels collected from Delaware Bay and Manasquan In the article by Fritz, Ragone, and Lutz in The Veliger, Vol. 34, No. 2, pp. 222-228, part of Figure 1 on p. 224 did not get printed due to an error by the printer. The complete figure is printed below. Trim the figure from this erratum, peel off the back of the paper, and position the figure on p. 224 of the April issue. Figure 1 Light micrograph of the acetate peel replica of the outer prismatic shell layer of a specimen of Mytilus edulis collected 13 May 1988 from the Manasquan River. The posterior shell margin is at the right; the inner shell surface is at the bottom. S, Fa, W, and Sp denote regions of the outer layer deposited in summer, fall, winter, and spring, respectively. A-G refer to locations where micrographs in Figure 3A-G, respectively, were taken. Scale bar = 500 um. River than in those collected from Sandy Hook Bay, per- haps reflecting the greater range in temperature and sa- linity observed at the two former sites. Furthermore, pop- ulations at the Delaware Bay (intertidal) and Manasquan River (barely subtidal, but exposed under certain wind conditions) sites had greater aerial exposure than those in Sandy Hook Bay (continuously submerged). Aerial ex- posure would increase the range in temperatures to which the animals were actually exposed. Seasonal changes in the shape of the posterior shell margin were reflected in, and most probably resulted from, seasonal changes in the microstructure of the outer layer. Prismatic needles near the posterior margin in mussels collected in spring and fall were long, evenly shaped, and deposited at angles of about 30° (Figure 2A, B; Table 1). In summer-collected mussels, however, prismatic needles near the posterior margin were stubby or lenticular in shape and deposited at angles ranging from 43 to 80° (Figure 2C, D; Table 1). Little or no shell growth occurred in winter (HILBISH, 1986), which resulted in a growth- cessation mark (Figure 1). The outer layer microstructure (near the posterior margin) of specimens collected in winter resembled that of fall-collected specimens in radial fracture section, but showed signs of dissolution (smoothed, etched, or indistinguishable prism tips) on the inner depositional surface similar to that shown in Figure 2D. Specimens collected in late winter (February), however, had prismatic needles resembling those in Figure 3F and G near the posterior shell margin, indicating that shell growth had resumed. Upon resumption of shell growth in late winter, a cone- shaped region of prisms was formed at the posterior shell margin in which prisms were oriented at angles ranging from 51 to 140° in individual shells (Table 1). Details of one cone-shaped region formed in late winter by the spec- imen in Figure 1 are shown in the series of scanning electron micrographs in Figure 3 (note locations where micrographs in Figure 3 were taken on Figure 1) and schematically represented in Figure 4. The prism cone has its apex at the intersection of the winter growth-cessation mark and the shell’s exterior surface (T in Figure 4). Prisms in the anterior portion of the cone (Figure 3A-C) were pointed anteriorly and deposited at angles as great as 140°. Prisms in the cone’s anterior portion were similar in shape, size, and tip morphology, but not in orientation, to those deposited in spring and fall (Figure 2A, B). Prisms in the center portion of the cone were deposited at angles of about 90° and formed a granular-textured inner surface (Figure 3D, E) similar to that found near the posterior margin in summer (Figure 2C, D). With increasing dis- tance in a posterior direction from the cone’s center, prism deposition angle gradually decreased to about 30° near the posterior margin (Figure 3F, G). The micrographs in Figure 3 were all photographed on or near the inner surface of the outer shell layer; in other words, in different portions of a single microgrowth in- crement. Thus, prisms in each of the three regions were presumably formed at the same time by different portions of the mantle just prior to collection in May 1988. Posterior portions of the mantle were depositing prisms at angles of about 30° (Figures 3F, 4) at the same time as more anterior portions of the mantle were depositing prisms at about 90° (Figures 3D, 4), 140° (Figures 3A, 4) and 23° (Figures 3A, 4). On the basis of the post-growth-cessation outer layer microstructure of numerous specimens, we hypoth- esize that prism orientation is initiated at the shell margin. Once prism orientation is initiated, individual prisms con- tinue to be deposited at that angle until the outer layer is Figure 2 Scanning electron micrographs of radial fracture (A, C) and inner depositional surfaces (B, D) of the outer prismatic shell layer of specimens of Mytilus edulis collected from Delaware Bay on 12 November 1986 (A), 19 June 1986 (B), and 14 August 1986 (C, D). Growth is to the right in all micrographs and the inner shell surface is at the bottom of A and C. Scale bars = 4 um. Page 226 The Veliger, Vol. 34, No. 2 Figure 3 Scanning electron micrographs of radial fracture (A, D, F) and inner depositional surfaces (B, C, E, G) of the outer prismatic shell layer of the specimen of Mytilus edulis shown in Figure 1. Micrographs A-G were taken at the locations shown on Figure 1. Arrow in A shows the location along the inner shell surface where B and C were taken. Growth in micrographs A and D-G is to the right; in B and C, growth is up. The inner shell surface is at the bottom of A and F, and parallel with and beyond the bottom of D. Scale bars: A = 10 um; B, C, E, G = 2 um; D, F = 5 um. Table 1 Angle (in degrees; mean and range) of outer layer prism deposition by specimens of Mytilus edulis collected in each season from three New Jersey locations. n = number of mussel specimens analyzed. Late Spring Summer Fall winter Mean 31.7 56.0 29.2 83.9 Range 26-45 43-80 20-36 51-140 n 15 9 9 10 Months Mar.-Jun. Jul.-Aug. Sep.—Nov. Feb. overlain by the pallial myostracum and the inner shell layer. This scenario explains the different orientation of prisms at various points along the inner surface of the outer layer which were all formed at the same time (present within the same microgrowth increment). Seasonal changes in the angle of outer layer prism de- position may be responsible for undulations and terracing of the shell’s exterior surface in summer and winter (Figure 1). Prism growth can be described by considering the ratio of the posterior (P) and inward (1) vectors of prism growth, P/I, which is equivalent to the inverse of the tangent of the angle of prism deposition. Prisms deposited at angles of 30° have a P/I ratio of 1.73, indicating that outer layer shell growth in the posterior direction is 1.73 times that in the inward direction. This results in sharply pointed posterior shell margins like those formed in spring and fall L. W. Fritz et al., 1991 Page 227 Figure 4 Line drawing showing outer layer prism orientation of the specimen in Figures 1 and 3. Prisms in the cone-shaped region (C) were initiated at the apex of the cone (T) in late winter 1987-1988 after the formation of the winter growth-cessation mark (w). Prisms anterior to the cone (A) were initiated in fall 1987 but deposited in late winter and spring. Prisms in the posterior region (P) were initiated and deposited in spring 1988. Scale and other notation as in Figure 1. (Figures 1, 4; Table 1). At prism deposition angles of greater than 45°, the P/I ratio is <1, resulting in a more blunt posterior margin similar to that formed in summer (Figures 1, 4), which had a mean prism deposition angle of 56° (Table 1). As prism angles approach 90°, like those found in the center axis of the cone, then P/I approaches O, yielding the steeply terraced shell exteriors found pos- terior to winter growth-cessation marks (Figures 1, 4). Other researchers (TAYLOR et al., 1969; TRAvis & GONSALVES, 1969; GREGOIRE, 1972; CARRIKER, 1978; CARTER, 1980) have observed that prism orientation with respect to the inner shell surface is not the same across the entire cross-sectional surface of the outer layer of Mytilus edulis. TAYLOR et al. (1969) described calcitic prisms that were “arranged into larger units, which appear[ed] to be broadly triangular in section but which [had] a conical form in three dimensions. Within these conical units, the needles radiate[d] from the apex of the cone, which point[ed] outwards towards the exterior of the shell. These broader units [were] developed quite sporadically in any one shell” (p. 81). The conically shaped regions described by ‘TAYLOR et al. (1969) are similar to those described here that were associated with seasonal changes in shell growth rates and resulted in undulations and terraces in the shell exterior. Regions of steeply angled prisms can also result from other disruptions to growth severe enough to form growth-ces- sation marks, such as those resulting from thermal effluents (KENNISH & OLSSON, 1975) or storms (FRITZ & LUTZ, 1986) identified in the shell microstructure of other bivalve species. Analyses of the outer layer microstructure of M. edulis could provide a record of the timing and possible severity of each disruption, creating a tool for sublethal environmental impact assessment. ACKNOWLEDGMENTS We thank the Division of Science and Research of New Jersey Department of Environmental Protection (N JDEP- DSR), and specifically Bruce Ruppel, for supporting this research, Dr. Richard Triemer and John Grazul for as- sistance with scanning electron microscopy, and Lisa War- go for photographic and collection assistance. Publication No. D-27204-1-87 of the New Jersey Agricultural Ex- periment Station, supported by state funds and NJDEP- DSR, and Contribution No. 90-38 of the Institute of Ma- rine and Coastal Studies, Rutgers University. LITERATURE CITED AMIARD, J.C.,C. AMIARD-TRIQUET, B. BERTHET & C. METAYER. 1986. Contribution to the ecotoxicological study of cadmi- um, lead, copper, and zinc in the mussel Mytilus edulis. Marine Biology 90:425-431. CaRRIKER, M. R. 1978. Ultrastructural analysis of dissolution of shell of the bivalve Mytilus edulis by the accessory boring organ of the gastropod Urosalpinx cinerea. Marine Biology 48:105-134. CaRTER, J. G. 1980. Environmental and biological controls of bivalve shell mineralogy and microstructure. Pp. 69-113. In: D. C. Rhoads & R. A. Lutz (eds.), Skeletal Growth of Aquatic Organisms: Biological Records of Environmental Change, Vol. 1, Geobiology Series. Plenum Press: New York. DieTH, M.R. 1985. The composition of tidally deposited growth lines in the shell of the edible cockle, Cerastoderma edule. Journal of the Marine Biological Association of the United Kingdom. 65:573-581. FARRINGTON, J. W., E. D. GOLDBERG, R. W. RISEBROUGH, J. H. Martin & V. T. BOwEN. 1983. U.S. “mussel watch” 1976-1978: an overview of the trace-metal, DDE, PCB, hydrocarbon, and artificial radionuclide data. Environmental Science and Technology 17:490-496. Fritz, L. W. & R. A. Lutz. 1986. Environmental pertur- bations reflected in internal shell growth patterns of Corbicula fluminea (Mollusca: Bivalvia). The Veliger 28:401-417. GREGOIRE, C. 1972. Structure of the molluscan shell. Pp. 45- 102. In: M. Florkin & B. T. Scheer (eds.), Chemical Zoology. Academic Press: New York. HIxsisu, T. J. 1986. Growth trajectories of shell and soft tissue in bivalves: seasonal variation in Mytilus edulis L. Journal of Experimental Marine Biology and Ecology 96:103-113. KENNISH, M. J., R. A. Lutz & D. C. RHoaps. 1980. Prep- aration of acetate peels and fractured sections for observation of growth patterns within the bivalve shell. Pp. 597-602. In: D. C. Rhoads & R. A. Lutz (eds.), Skeletal Growth of Aquatic Organisms: Biological Records of Environmental Change, Vol. 1, Geobiology Series. Plenum Press: New York. KENNISH, M. J. & R. K. OLsson. 1975. Effects of thermal discharges on the microstructural growth of Mercenaria mer- cenaria. Environmental Geology 1:41-064. Page 228 Lutz, R. A. 1976. Annual growth patterns in the inner shell layer of Mytilus edulis L. Journal of the Marine Biological Association of the United Kingdom 56:723-731. Lutz, R. A. & D. C. RHoaDs. 1980. Growth patterns within the molluscan shell: an overview. Pp. 203-254. In: D. C. Rhoads & R. A. Lutz (eds.), Skeletal Growth of Aquatic Organisms: Biological Records of Environmental Change, Vol. 1, Geobiology Series. Plenum Press: New York. NATIONAL ACADEMY OF SCIENCES. 1980. The International Mussel Watch. National Academy of Sciences: Washington, D.C. 248 pp. PANNELLA, G. & C. MACCLINTOCK. 1968. Biological and en- vironmental rhythms reflected in molluscan shell growth. Journal of Paleontology 42:64-80. STROMGREN, T., M. V. NIELSEN & K. UELAND. 1986. Short- term effect of micro-encapsulated hydrocarbons on shell growth of Mytilus edulis. Marine Biology 91:33-39. SuniLa, I. & R. LINDSTROM. 1985. Survival, growth and shell The Veliger, Vol. 34, No. 2 deformities of copper- and cadmium-exposed mussels (Myti- lus edulis L.) in brackish water. Estuarine, Coastal and Shelf Science 21:555-565. TayLor, J. D., W. J. KENNEDY & A. HALL. 1969. The shell structure and mineralogy of the Bivalvia. Introduction. Nu- culacea-Trigonacea. Bulletin of the British Museum (Nat- ural History), Series D, Zoology, Supplement 3:1-125. Travis, D. F. & M. GONSALVES. 1969. Comparative ultra- structure and organization of the prismatic region of two bivalves and its possible relation to the chemical mechanism of boring. American Zoologist 9:653-661. WapaA, K. 1961. Crystal growth of molluscan shells. Bulletin, National Pearl Research Laboratory (Japan) 7:703-828. ZOTTOLI, R. A. & M. R. CARRIKER. 1974. Burrow morphology, tube formation and microarchitecture of shell dissolution by the spionid polychaete Polydora websterr.. Marine Biology 27: 307-316. XN The Veliger 34(2):229-231 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 NOTES, INFORMATION & NEWS Sexual Dimorphism in Castalia undosa undosa Martens, 1827 (Bivalvia: Hyriidae) by Wagner E. P. Avelar, Alvaro da Silva Costa, Antonio Jose Colusso, and Creusa M. R. Dal Bo Department of Biology, and Department of Geology, Mathematics and Physics, Faculty of Philosophy, Sciences and Letters of Ribeirao Preto, University of Sao Paulo, 14049 Ribeirao Preto, SP, Brazil The entire gamut of sex differentiation can be found among bivalves, from species with strictly separate sexes to species that are “almost invariably functionally her- maphroditic” (CoE, 1943). In general, South American freshwater bivalves are reported to be dioecious species with no distinction between males and females in terms of shell shape characteristics. ORTMAN (1921a) has reported that the sex of certain species of North American Lampsilis and 7runcilla can be determined on the basis of shell shape. According to CoE (1943), for certain dioecious species of Unio and Astarte, the two sexes can be distinguished by shell shape in adult animals. ORTMAN (1921b) did not re- cord any case of hermaphroditism for South American naiades or shell traits that might distinguish males from females. In the South American bivalve families Hyriidae and Mycetopodidae, hermaphroditism was recorded for Ano- dontites trapesalis Lamarck, 1819, and Anodontites trape- zeus Spix, 1827, by HEBLING (1976), and for Mycetopoda legumen Martens, 1888, by VEITENHEIMER & MANSUR, (1978). According to BONETTO (1951), hermaphroditism is common in the genus Anodontites. Among Hyriidae, hermaphroditism was observed in Diplodon delotundus ex- pansus Kuster, 1865 (CuRIAL & LANGE, 1974) and in Diplodon rotundus gratus Wagner, 1827 (HEBLING & PENTEADO, 1974). Gonochorism with no macroscopic distinction between males and females was observed in Diplodon chilensis chi- lensis (Gray) by PEREDO & PARADA (1984). BONETTO (1965), in a review of the tribe Cristalliini, reported no data concerning bivalve sexuality. MANSUR (1972), study- ing the morphology of the digestive tract of Castalia undosa martensi Ihering, 1891, made no mention of sex. OLIVEIRA (1985), when studying the gametogenic cycle of C. undosa undosa Martens, 1827, found only two hermaphroditic specimens. While studying the functional anatomy of Castalia un- dosa undosa, we noticed that the shells of dissected animals differed in beak conformation (posterior region of the an- imal), with some of them exhibiting acute angles and others rounded angles. Thus, the objective of the present study was to determine the existence of sexual differences be- tween male and female C. undosa undosa, manifested as a posteroventral deflection of the shell in males that renders the region pointed. This is the first study demonstrating the presence of sexual dimorphism in the adult shell among freshwater bivalves from South America, providing data that will contribute to our knowledge about Castalia undosa undosa. Materials and Methods Live specimens of Castalia undosa undosa were collected from the Pardo River in the municipality of Ribeirao Preto (21°07'S and 47°45'W), state of Sao Paulo, Brazil. The animals live buried in muddy substrates, usually under the shade of bushes and trees or among the roots of aquatic plants, and can be captured only by probing the river bottom with the feet or the hands. Lots of 25 animals each were collected at random at different sites at three-month intervals for a total of 100 specimens, and carried to the laboratory where they were anesthetized with magnesium chloride and fixed in Bouin’s for histological examination. The animals were divided into two groups according to conformation of the shell beak. Group 1 consisted of an- imals showing a sharp-pointed shell beak, and group 2 consisted of animals with a rounded shell beak (Figure 1). The transverse (Figure 2) and longitudinal (Figure 3) angular apertures of each shell were measured with the aid of a fixed spindle transferrer, and a gonad biopsy was taken from each animal. The 100 specimens were sectioned transversely at the level of the region posterior to the stomach and the posterior half was dehydrated and embedded in paraffin. Approx- imately twelve 10-wm-thick histological sections were cut transversely, alternated every 5 mm, and stained with he- matoxylin-eosin. The purpose of this procedure was to certify the sex and to determine the arrangement of male and female follicles in the visceral mass. The sex of each animal was determined by light microscopy. Data were analyzed statistically by the Student ¢-test. Results and Discussion Of the specimens of Castalia undosa undosa collected, 52 were females and 48 males. Mean female length was 6.03 cm and mean male length was 6.35, with a mean overall size for males and females of 6.19 cm. The smallest spec- imen was 4.43 cm long and the largest 7.6 cm. The mean (+ SEM) transverse angular aperture was 64.8 + 0.65 for females and 6.4 + 0.66 for males, and the Page 230 1 2 The Veliger, Vol. 34, No. 2 Explanation of Figures 1 to 3 Figures 1-3. Castalia undosa undosa. Figure 1. Drawing of the left valves of males and females showing the differences between them. Figure 2. Ventral view of the shell to show the transverse angle (a). Figure 3. Lateral view of left valve to show the longitudinal angle (8). mean longitudinal angular aperture was 67.7 + 0.65 for females and 64.3 + 0.56 for males. It can be seen that both values were larger for females than for males, with statistically significant differences in both cases (P < 0.001). When sex determination was attempted visually with the unaided eye without using a fixed spindle transferrer, the error for the 100 specimens was on the order of 16%. The error occurred especially for young specimens mea- suring less than 5 cm, because in these juveniles the pos- teroventral deflexion of the shell is not as evident. In South American freshwater dioecious bivalves, dimorphism is usually observed macroscopically when the marsupium of Notes, Information & News pregnant females is full of eggs or embryos during the spawning phase. At any other time (z.e., during the phases preceding or following spawning) a gonad biopsy is needed to identify the sexes. According to CoE (1943), in some species the functional sex phase of some or all individuals may change throughout the life of the animals. In this respect, we used as a starting point a study by OLIVEIRA (1985) who determined the annual gametogenesis cycle of Castalia undosa undosa in an investigation of 120 adult animals in which she only de- tected two hermaphrodite specimens. In a study of the functional anatomy of C. undosa undosa, AVELAR & SANTOS (1991) found no cases of hermaphroditism. No such cases were detected among the 100 specimens studied in the present investigation. The ideal approach would be to study juveniles of C. undosa undosa in which the dimorphic shell trait is still not manifested in order to observe the definition of sexuality. On the basis of the present results, we conclude that the sexuality of Costalia undosa undosa can be determined by the shape of the shell in adult animals in which the pos- terior beak of the valves presents smaller transverse and longitudinal angles in males than in females. Our research was supported by CNPq (Conselho Na- cional de Desenvolvimento Cientifico e Tecnologico), grant No. 500083/88-6. We are grateful to M. S. Ribeiro for the drawings. Literature Cited AVELAR, W. E. P. & S.C. D. SANTos. 1991. Functional mor- phology of Castalia undosa undosa (Bivalvia, Hyriidae). The Veliger 34(1):21-31. BoneTTo, A. A. 1951. Acerca de las formas larvales de Mu- telidae Ortmann. Jornadas Icticas Santa Fe 1(1):1-8. BoneTTo, A. A. 1965. Las almejas sulamericanas de la tribu Castalliini. Physis 25(69):187-196. CoE, W. R. 1943. Sexual differentiation in Mollusks I. Pe- lecypods. Quarterly Review of Biology 18(2):154-164. CurIAL, O. & R. R. LANGE. 1974. Hermafroditismo em Diplo- don delotundus expansus. Arquivos de Biologia e Tecnologia 17(2):109-110. HEBLING, N. J. 1976. The functional morphology of Anodon- tites trapezeus (Spix) and Anodontites trapesialis (Lamarck). (Bivalvia: Mycetopodidae). Boletim de Zoologia, Sao Paulo 1:265-298. HEBLING, N. J. & A. M. G. PENTEADO. 1974. Anatomia fun- cional de Diplodon rotundus gratus Wagner, 1827 (Mollusca, Bivalvia). Revista Brasileira de Biologia 34(1):67-80. Mansur, M. C.D. 1972. Morfologia do sistema digestivo de Castalia undosa martensi (Ihering, 1891) (Bivalvia, Hyriidae). Iheringia Zoologia 43:21-34. OLIVEIRA, M. B. F. C. 1985. Ciclo gametogenico de Castalia undosa undosa Martens—1827 (Bivalvia Hyriidae). Ribeirao Preto—Departamento de Biologia. Faculdade de Filosofia, Ciéncias e Letras de Ribeirao Preto USP. Monografia. 51 2) OrTMaN, A. E. 1921a. A monograph of the naiades of Penn- sylvania. Memoirs of the Carnegie Museum 8(3):1-384. ORTMAN, A. E. 1921b. South American naiades; a contribution of the knowledge of the freshwater mussels of South America. Memoirs of the Carnegie Museum 8(3):451-670. Page 231 PEREDO, S. & E. ParRaDA. 1984. Gonadal organization and gametogenesis in the freshwater mussel Diplodon chilensis chilensis (Mollusca: Bivalvia). The Veliger 27(2):126-133. VEITENHEIMER, I. L. & M. C. D. Mansur. 1978. Morfologia, histologia e ecologia de Mycetopoda legumen (Martens, 1888)—Bivalvia, Mycetopodidae, Iheringia Zoologia 92:33- Wile International Commission on Zoological Nomenclature The following applications were published on 29 June 1990 in Vol. 47, Part 2 of the Bulletin of Zoological No- menclature. Comment or advice on these applications is invited for publication in the Bulletin and should be sent to the Executive Secretary, I.C.Z.N., % The Natural His- tory Museum, Cromwell Road, London SW7 5BD, Unit- ed Kingdom. Case 2630—Helix (Helicigona) barbata Ferussac, 1832 (currently Lindholmiola barbata; Mollusca, Gastropoda): proposed confirmation of lectotype designation. Brought by D. Kadolsky. Case 2699—Rissooidea (or Rissoacea) Gray, 1847 (Mol- lusca, Gastropoda): proposed precedence over ‘Truncatel- loidea (or Truncatellacea) Gray, 1840. Bought by G. Ro- senberg and G. M. Davis. Case 1643—M)ytilus anatinus Linnaeus, 1758 (currently Anodonta anatina; Mollusca, Bivalvia): proposed desig- nation of a neotype. Brought by P. B. Mordan and F. R. Woodward. Bulletin of Zoological Nomenclature Offprints of Molluscan Cases An opportunity to keep abreast of nomenclatural problems in the Mollusca. For the price of US$25 (£ 15) a year, individual scientists can receive offprints of all cases (Ap- plications, Comments, and Opinions) relating to the Mol- lusca as soon as they are published in the Bulletin of Zoo- logical Nomenclature. This offer is for the years 1990 and 1991, but back stock can be ordered back to 1980. Send your order with US$25 for each year wanted to: I.C.Z.N., % The Natural History Museum, Cromwell Road, Lon- don SW7 5BD, United Kingdom. First Congress of Latin American Malacology The First Congress of Latin American Malacology is scheduled to be held in Caracas, Venezuela, from 15 to 19 July 1992. Field trips to four different areas are scheduled on the 19th and 20th. Official languages include Spanish, Portuguese, and English. Sessions will be held on general malacology and applied malacology, the latter with a spe- cial focus on Strombus gigas. For more information, write to: Lic. Roberto Cipriani, Universidad Simo6n Bolivar, Apartado Postal 89.000, Ca- racas 1080, Venezuela. The Veliger 34(2):232 (April 1, 1991) THE VELIGER © CMS, Inc., 1991 BOOKS, PERIODICALS & PAMPHLETS A Systematic and Bibliographic List of the Japanese Land Snails by HirRosHI MInaTo. 1988 (August 8). Nihon Rikusan Kairui Soumokuroku Kankokai, Shirahama, Japan. ix + 294 pp. The fundamentals of the Japanese land mollusk fauna are now readily accessible, between this book for the lit- erature and Colored Illustrations of the Land Snails of Japan, by Masao Azuma (Osaka, Hoikusha Publishing Com- pany, 1982), for pictures and identification. Few other land snail faunas (and none of comparable geographic extent) are so concisely covered. Only an atlas of range maps would be needed to give a complete, basic picture. This work provides synonymies for all the land mollusks known from Japan, including the Ryukyu Islands. Ref- erences to each species are in chronological order. Authors’ names and journal titles (even those of Asian origin) are in Roman characters, which, theoretically, should make it possible to access all of the pertinent literature. (In the terminal bibliography, works by Asian authors, including authors’ names, appear only in kanji characters; hence an American-speaker like me cannot just flip to the back and get the complete reference to a paper of interest.) The classification generally follows that of Solem (pp. 49-97 in V. Fretter & J. Peake, eds., Pulmonates, Vol. 2A. Systematics, Evolution and Ecology. London, Academic Press, 1978). One new taxon is proposed, the subfamily Euhad- rinae of Bradybaenidae, based on Euhadra Pilsbry, 1890. There is no statement of characters purporting to differ- entiate it from other taxa (or reference to such a statement) and Euhadrinae therefore is probably a nomen nudum. It would have been interesting to know in what respect this subfamily was thought to differ from, for example, Brady- baeninae, Aegistinae, or the recently proposed Monaden- iinae Nordsieck, 1987. Barry Roth Information for Contributors Manuscripts Manuscripts must be typed on white paper, 82” by 11”, and double-spaced throughout (including references, figure legends, footnotes, and tables). If computer generated copy is to be submitted, margins should be ragged right (7.e., not justified). To facilitate the review process, manuscripts, including figures, should be submitted in triplicate. The first mention in the text of the scientific name of a species should be accompanied by the taxonomic authority, including the year, if possible. Underline scientific names and other words to be printed in italics. Metric and Celsius units are to be used. The sequence of manuscript components should be as follows in most cases: title page, abstract, introduction, materials and methods, results, discussion, acknowledgments, lit- erature cited, figure legends, figures, footnotes, and tables. The title page should be on a separate sheet and should include the title, author’s name, and address. The abstract should describe in the briefest possible way (normally less than 200 words) the scope, main results, and conclusions of the paper. Literature cited References in the text should be given by the name of the author(s) followed by the date of publication: for one author (Smith, 1951), for two authors (Smith & Jones, 952). and for more than two (Smith ef al., 1953). The “literature cited” section must include all (but not additional) references quoted in the text. References should be listed in alphabetical order and typed on sheets separate from the text. Each citation must be complete, with all journal titles unabbreviated, and in the following form: a) Periodicals Cate, J. M. 1962. On the identifications of five Pacific Mitra. The Veliger 4:132-134. b) Books Yonge, C. M. & T. E. Thompson. 1976. Living marine molluscs. Collins: London. 288 pp. c) Composite works Feder, H. M. 1980. Asteroidea: the sea stars. Pp. 117-135. In: R. H. Morris, D. P. Abbott & E. C. Haderlie (eds.), Intertidal Invertebrates of California. Stanford Univ. Press: Stanford, Calif. Tables Tables must be numbered and each typed on a separate sheet. Each table should be headed by a brief legend. Figures and plates Figures must be carefully prepared and should be submitted ready for publication. Each should have a short legend, listed on a sheet following the literature cited. Text figures should be in black ink and completely lettered. Keep in mind page format and column size when designing figures. Photographs for half-tone plates must be of good quality. They should be trimmed off squarely, arranged into plates, and mounted on suitable drawing board. Where necessary, a scale should be put on the actual figure. Preferably, photographs should be in the desired final size. It is the author’s responsibility that lettering is legible after final reduction (if any) and that lettering size is appropriate to the figure. Charges will be made for necessary alterations. Processing of manuscripts Upon receipt each manuscript is critically evaluated by at least two referees. Based on these evaluations the editor decides on acceptance or rejection. Acceptable manuscripts are returned to the author for consideration of comments and criticisms, and a finalized manuscript is sent to press. The author will receive from the printer two sets of proofs, which should be corrected carefully for printing errors. At this stage, stylistic changes are no longer appropriate, and changes other than the correction of printing errors will be charged to the author at cost. One set of corrected proofs should be returned to the editor. An order form for the purchase of reprints will accompany proofs. If reprints are desired, they are to be ordered directly from the printer. Send manuscripts, proofs, and correspondence regarding editorial matters to: Dr. David W. Phillips, Editor, 2410 Oakenshield Road, Davis, CA 95616 USA. CONTENTS — Continued Seasonal changes in outer shell layer microstructure of Mytilus edulis in New Jersey, USA. LOWELL W. FRITZ, Lisa M. RAGONE, AND RICHARD A. LUTZ .......... 222 NOTES, INFORMATION & NEWS Sexual dimorphism in Castalia undosa undosa Martens, 1827 (Bivalvia: Hy- rildae). WAGNER E. P. AVELAR, ALVARO DA SILVA CosTa, ANTONIO JOSE COLUSSO, AND @REUSAMECR: TDA BO2i8e iu Fed ic es 229 VELIGER A Quarterly published by CALIFORNIA MALACOZOOLOGICAL Berkeley, California R. Stohler, Founding Editor Lx 78) VA\ (NORE: SMITHSON YOCIETY, INC. — AUG 20 199] LIBRARICL July 1, 1991 CONTENTS Distribution and diversity patterns of Australian pupilloid land snails (Mollusca: Pulmonata: Pupillidae, s.1.). J TUIRT SIOVELIINT =) 6:53. Shear BU alls ot ak cach to a0 er og oR Pre 233 Terrestrial snails (Gastropoda) in Dominican amber. GEORGE © POINAR; JR. AND BARRY ROTH 206.620 e ec ody ta ee eke 253 Late Quaternary Chaenaxis tuba (Pupillidae) from the Sonoran Desert, south- central Arizona. IMA MEAD AND THOMAS R. VAN DEVENDER .............22..-...5. 259 Generic identity and relationships of the northeastern Pacific buccinid gastropod Searlesia dira (Reeve, 1846). CEE RAMA | PENVSERMIEN Me) 6 202i = cont Mat or he ule ltt isteds Lie wor agate neem OL 264 Four new species and a new genus of opisthobranch gastropods from the Pacific coast of North America. SERRENG@ ENV I0g GOSEINERG en beg led fy UNE Us ace hyn 8 ko is chee ah plea Ala Gaal a PAOD Morphological variability in the gastroesophageal ganglion of the nudibranch Tritonia diomedea. IROGERW ID MIEON GUE Yate eee t com 2c ett tat ducteernaal kate d torent te Be 291 Female genital system of Chorus giganteus (Prosobranchia: Muricidae). ROB ERGO NRAMIE LO were tenes See. A 6 Biante ayo ate Oeste es Sle. 3 297 CONTENTS — Continued The Veliger (ISSN 0042-3211) is published quarterly on the first day of January, April, July, and October. Rates for Volume 34 are $28.00 for affiliate members (including domestic mailing charges) and $58.00 for libraries and nonmembers (zn- cluding domestic mailing charges). For subscriptions sent to Canada and Mexico, add US $4.00; for subscriptions sent to addresses outside of North America, add US $8.00, which includes air-expedited delivery. Further membership and subscription infor- mation appears on the inside cover. The Veliger is published by the California Ma- lacozoological Society, Inc., % Museum of Paleontology, University of California, Berkeley, CA 94720. Second Class postage paid at Berkeley, CA and additional mailing offices. POSTMASTER: Send address changes to The Veliger, Museum of Paleon- tology, University of California, Berkeley, CA 94720. ISSN 0042-3211 Number 3 THE VELIGER Scope of the journal The Veliger is open to original papers pertaining to any problem concerned with mol- lusks. This is meant to make facilities available for publication of original articles from a wide field of endeavor. Papers dealing with anatomical, cytological, distributional, eco- logical, histological, morphological, physiological, taxonomic, evolutionary, etc., aspects of marine, freshwater, or terrestrial mollusks from any region will be considered. Short articles containing descriptions of new species or lesser 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 specimen must be included in the manuscript. Type localities must be defined as accurately as possible, with geographical longitudes and latitudes added. Very short papers, generally not exceeding 500 words, will be published in a column entitled “NOTES, INFORMATION & NEWS”; in this column will also appear notices of meetings, as well as news items that are deemed of interest to our subscribers in general. Editor-in-Chief David W. Phillips, 2410 Oakenshield Road, Davis, CA 95616, USA Editorial Board Hans Bertsch, National University, Inglewood, California James T. Carlton, University of Oregon Eugene V. Coan, Research Associate, California Academy of Sciences, San Francisco J. Wyatt Durham, University of California, Berkeley William K. Emerson, American Museum of Natural History, New York Terrence M. Gosliner, California Academy of Sciences, San Francisco Cadet Hand, University of California, Berkeley Carole S. Hickman, University of California, Berkeley David R. Lindberg, University of California, Berkeley James H. McLean, Los Angeles County Museum of Natural History Frank A. Pitelka, University of California, Berkeley Peter U. Rodda, California Academy of Sciences, San Francisco Clyde F. E. Roper, National Museum of Natural History, Washington Barry Roth, Santa Barbara Museum of Natural History Judith Terry Smith, Stanford University Ralph I. Smith, University of California, Berkeley Wayne P. 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Send manuscripts, proofs, books for review, and correspondence regarding editorial matters to: Dr. David W. Phillips, Editor, 2410 Oakenshield Road, Davis, CA 95616, USA. THIS PUBLICATION IS PRINTED ON ACID-FREE PAPER. The Veliger 34(3):233-252 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Distribution and Diversity Patterns of Australian Pupilloid Land Snails (Mollusca: Pulmonata: Pupillidae, s.1.) by ALAN SOLEMT Department of Zoology, Field Museum of Natural History, Roosevelt Road and Lake Shore Drive, Chicago, Illinois 60605-2496, USA Abstract. Data are presented on the distribution and diversity patterns of 34 native Australian pupilloid land snails. In addition, mention is made of two introduced species. Most Queensland and New South Wales species have not been revised and distributional data for these taxa are sparse. Therefore, they are not included. Eight of the nine genera range outside of Australia. The monotypic Glyptopupoides Pilsbry, 1926, is the only restricted endemic. Four of the 34 native species also live in Indonesia or New Guinea. The south and west coasts of Australia have a limited fauna of three genera and four restricted endemic species each, plus a minor intrusion of Gastrocopta deserti Pilsbry, 1917, from the “Red Centre.” No pupilloids have been collected in the humid southwestern corner of Western Australia, Tasmania, or most of Victoria. The ‘““Red Centre” has seven species, two with quite restricted ranges, in three genera. One “Red Centre” species, G. deserti, has the widest range of any Australian pupilloid, extending from western Queensland to the North West Cape in Western Australia, as far north as the south fringes of the Kimberley, and then south to the Flinders Ranges in South Australia. The Kimberley in Western Australia and the ““Top End” of the Northern Territory have the greatest diversity in both genera and species, with eight genera and 19 species present. Local distribution in this region is rather complex and correlates mainly with moisture regimes. Patterns of local diversity also are discussed. + Editor’s note: Several weeks before his death on 26 February 1990, Alan Solem mentioned to one of his colleagues at the Field Museum, Vickie Huff, that he was working on “the pupillid range paper” at home and that he had one part to finish before submitting it to The Veliger. Regrettably, he did not have the opportunity. Ms. Huff, however, was able to gather all of the previously completed, computer-generated figures and to retrieve the text from Alan’s computer. She submitted the posthumous manuscript to The Veliger in accordance with Alan’s expressed intent; it was evaluated by three reviewers, and accepted for publication. Although we suppose that the manuscript was nearly complete, readers may notice a few places where Alan was likely to have returned to fill in a section or to make a revision. Nev- ertheless, only minor editorial changes were made in the sub- mitted manuscript in order to preserve, as much as possible, the author’s intent. After the initial manuscript submission, Mar- garet Baker of the Field Museum took over the responsibility of seeing the project through to completion. Without her consid- erable efforts we would not now have the opportunity to read Alan Solem’s last contribution to science. D.W.P. INTRODUCTION As a by-product from extensive field surveys of the ca- maenid land snails found in the western two-thirds of Australia, collections of the small-sized and much less di- verse non-camaenid families have been accumulated. Pu- pilloid taxa proved to be especially abundant and mod- erately diverse. Their shells provide a wealth of characters for species delineation. It was thus possible to review the species found in Australia and determine if they have ex- tralimital ranges. In the absence of any contemporary ge- neric or family level phylogenetic hypotheses and anatom- ical data on the Australian taxa, it proved impossible to expand these studies into reviews of generic affinities or historical biogeography. The systematic bases for this study are the survey of Australian members of the basically Southeast Asian-In- donesian genus Glyzotrachela Tomlin, 1930 (see SOLEM, 1981); a faunal review of pupilloid species from the south Page 234 The Veliger, Vol. 34, No. 3 Li ! ! Ie | i ie 110° 115° 120° 425 130° 135 440’ 145° 150° 155° Figure 1 Map of Australia showing approximate outlines of regions dis- cussed in text: NSW, New South Wales; NT, Northern Terri- tory; QLD, Queensland; SA, South Australia; TAS, Tasmania; VIC, Victoria; WA, Western Australia; 1, Dampierland; 2, Kim- berley; 3, “Top End”; 4, Gulf of Carpentaria; 5, Torres Strait; 6, Cape York Peninsula; 7, Townsville, QLD; 8, “Red Centre”’; 9, Flinders Ranges; 10, Pilbara; 11, Shark Bay; 12, North West Cape; 13, 80 Mile Beach. and west coasts of Australia (see SOLEM, 1986); and a monographic review of all non-camaenid land snails from the Kimberley region of Western Australia and all of the Northern Territory (see SOLEM, 1989). These studies not only greatly extended the known rang- es of most taxa and resulted in recognition of several new ones, but permitted preparing the first comprehensive set of distributional maps for any Australian land snail family (Figures 2-32). The patterns of both distribution and di- versity were unexpected. The extent to which there are 122° 124° 126° 128° 130° 132° 434° 136° l 128° 130° i 134° Nesopupa mooreana + 444 records Figure 2 Records of Nesopupa mooreana in the Kimberley and “Top End.” 122° 124° 126° 128° 130° 132° 134° 136" 40° 12° eal 122° 124° 126° 128° 130° 132° 134° 136° 138° 2 records Gastrocopta mussoni 0 42 records Nesopupa novopommerana + Figure 3 Records of Nesopupa novopommerana and Gastrocopta mussoni in the Kimberley and “Top End.” Nesopupa novopommerana has been recorded from New Britain, Bismarck Archipelago, and Tanimbar Island. Gastrocopta mussoni has been recorded else- where only from Mt. Morgan, Queensland. extralimital records for both genera and species was equal- ly surprising. I recognize 34 native (32 named) and two introduced species that belong to eight genera. Some additional taxa were collected in the Cape York Peninsula and along the Gulf of Carpentaria in a 1988 survey. Although brief mention is made of them below, it was not possible to prepare formal descriptions or add their localities to the distribution maps at this time. A list of the recognized taxa and references to recent literature and illustrations are given in Appendix 1. One additional genus, the Queensland to New South Wales plus New Caledonia Cylindrovertilla O. Boettger, 1880, 122° 424° 126° 128 130° 432° 434° 136" 138° Figure 4 Records of Pupisoma orcula in the Kimberley and “Top End.” Extralimital range is from India and Japan to New Guinea, Hawaii, and Tuamotu Islands. A. Solem, 1991 14° 16° ——, SCE PCC PORE Ao ; 122° 124° 126 128 130 132 134 136 138 Pupisoma circumlitum + 59 records Pupisoma sp 0 5S records Figure 5 Records of Pupisoma circumlitum and Pupisoma sp. in the Kim- berley and “Top End.” Pupisoma circumlitum is found also from the Gulf of Carpentaria and Torres Strait south as far as Grafton, New South Wales. Pupisoma sp. has not been recorded elsewhere. could not be reviewed because of limited material in col- lections; and two unquestionably valid New South Wales species, Gastrocopta strangeana Iredale, 1937 (= strangei Pfeiffer, 1854, non Benson, 1853) and Gastrocopta hedleyi Pilsbry, 1917, are omitted for the same reason. References to these, and a few additional names that probably are synonyms, also are listed in Appendix 1. PREVIOUS STUDIES The classic world monograph of the pupilloid land snails included systematic reviews of Australian taxa (PILSBRY, REVISED Figure 6 Records of Gastrocopta in Australia (revised species only). 12° Page 235 115° 120° 125° 130° 135° 140° 145° 150° Gastrocopta deserti 0 70 records | Gastrocopta margaretae X 112 records 0 40° Gastrocopta simplex + 426 records ‘ + . Wa + 40 LL . ! . ! . . 1. 1 + ! . | . L . 1 7 110 115 120 125 130 135 140 145 150 155 Figure 7 All confirmed records of Gastrocopta deserti, G. margaretae, and G. simplex. 1916-1918; 1920-1921; 1922-1926). Pilsbry provided ex- cellent illustrations, a masterly review of previous litera- ture, and many comments about affinities of the Australian species. Very little anatomical data was available for any pupilloids, and none for members of the Australian fauna. A biogeographic summary of the pupilloid taxa was presented in PILSBRY (1934-1935:139-169). His opening statement is worth repeating: ‘““The family Pupillidae is Gastrocopta deserti 0 14 records Gastrocopta margaretae + 80 records Figure 8 Records of Gastrocopta desertt and G. margaretae in South Aus- tralia and bordering areas. Page 236 Gastrocopta deserti U records Gastrocopta merasnetae + records Gastrocopta pilbarana xX records Gastrocopta wallabyensis W records Pupoides myoporinae 0 records 415° 120° 125° 130° Figure 9 Records of Gastrocopta deserti, G. margaretae, G. pilbarana, G. wallabyensis, and Pupoides myoporinae in Western Australia below 80 Mile Beach. essentially a group of the northern continents. The data now at hand indicate Eurasia as the main area of evolution and radiation. All of the major groups (subfamilies) occur in this continent. Of about 50 genera recognized in the family, 38, or about 75 percent, are represented in Eurasia, either living or as Tertiary fossils.” ‘The southern continents and islands have, in addition to northern genera which extend into them, only about 8 Jo ie 4 1 = Heath = el — | —t : 422° 124 126 128 130 132 4134 136 138 Gastrocopta deserti X 5 records Gastrocopta mussoni 0 2 records Gastrocopta simplex + 435 records Figure 10 Records of Gastrocopta deserti, G. mussoni, and G. simplex in the Kimberley and “Top End.” The Veliger, Vol. 34, No. 3 120° 125° 130° 435° 440° Gastrocopta larapinta / 47 records Gastrocopta macdonnelli 0 46 records Gastrocopta tatei 11 records Figure 11 Records of Gastrocopta larapinta, G. macdonnelli, and G. tate in the Kimberley and Northern Territory. Gastrocopta macdonnelli also occurs from Torres Strait to Townsville, Queensland. endemic genera. . .. There is no trace of Antarctic elements suggesting dispersal via Antarctica” (PILSBRY, 1934-1935: 139-140). In a series of nomenclatural notes, checklists, and faunal surveys, IREDALE (1930, 1933, 1937a, b, 1939, 1940, 1941) Gastrocopta pilbenena x 8 records Gastrocopta tatei + 44 records Gastrocopta wallabyensis * 4 records Pupoides ischnus 0 5 records Figure 12 Records of rare Australian species: Gastrocopta pilbarana, G. tater, G. wallabyensis, and Pupoides ischnus. A. Solem, 1991 414" 416° 118° 120° 22° F 237 - Gastrocopta pilbarana 0 8 records | Gastrocopta wallabyensis X 4 records 25° 24° 28° 4 29° 29° 30° 30° ; 34 Figure 13 Records of Gastrocopta pilbarana and G. wallabyensis along the coast of central Western Australia. proposed eight new generic units (Famarinia, Gyrodaria, Imputegula, Omegapilla, Papualbinula, Somniopupa, The- mapupa, and Walliwertilla); 12 new species or subspecies; and one replacement name (Gastrocopta strangeana). The net effect of the generic names was to “‘isolate” the Aus- tralian taxa from those living elsewhere. None of Iredale’s new genera are considered valid, and 11 of his 12 new taxa are placed in synonymy. The 12th, Cylindrovertilla fabreana boynensis Iredale, 1937, may prove to be valid. His replacement name is accepted. In the period since Iredale’s taxonomic splitting, the Australian pupilloids have had brief biogeographic men- tion in MCMICHAEL & IREDALE (1969) and BiIsHop (1981: 934-936, 940); cursory comments in the faunistic hand- books of SMITH & KERSHAW (1979:102-110; 1981:65, 1926); a brief historical review of knowledge concerning the South Australian land mollusks (SMITH, 1985); and the three revisions by SOLEM (1981, 1986, 1989). No anatomical data have been recorded, leaving ques- tions of both family and generic level classification and phylogeny completely unanswerable at this time. The de- gree of classificatory uncertainty is demonstrated by Table 1, which lists the family level units of pupilloids used for Australian taxa in the last half century. Table 2 allocates the Australian genera to the subfamilies used in the con- servative classification of PILSBRY (1948), which I have chosen to follow in this study. It is not possible to suggest ancestor-descendant relationships among these genera or Page 237 113° 414° 415° 116° 417° 21° f Gastrocopta deserti + 24° Gastrocopta pilbarana 0 Gastrocopta wallabyensis xX 4 records 7 records 2 records 25 25° 26° 26° 27° 27° I\ 413° 114° 445° 116° Figure 14 Records of Gastrocopta deserti, G. pilbarana, and G. wallabyensis in Western Australia between Shark Bay and the North West Cape. to construct meaningful phylogenies. The few published anatomical studies on Holarctic taxa do show that consid- erable structural variation exists, but too few taxa have been studied to permit phylogenetic studies of the main Holarctic groups, much less the world fauna. MATERIALS All records utilized in this study are based upon specimens examined by the author. The early literature contains many misidentifications, and thus only specimen-confirmed lo- calities have been included. The records listed by SOLEM (1981, 1986, 1989) have been supplemented by a review of the collections in the Western Australian Museum, Perth; South Australian Museum, Adelaide; Australian Muse- um, Sydney; Museum of Victoria, Melbourne; Queens- land Museum, Brisbane; and the private collections of Fred Aslin (Mount Gambier, South Australia) and Vince Kes- sner (Adelaide River, Northern Territory). Extensive col- lections in 1988 from continental shelf islands along the Page 238 The Veliger, Vol. 34, No. 3 Table 1 Previous family level classifications of pupilloid taxa. IREDALE (1940) PILsBRY (1948) ZILCH (1959) SOLEM (1978) TILLIER (1989) Pupillacea Pupillacea Pupillacea Gastrocoptidae Pupillidae Vertiginidae Pupillidae Pupillidae Cylindrovertillidae Nesopupinae Nesopupinae Chondrinoidea Pupoididae Gastrocoptinae Gastrocoptinae Chondrinidae Pupisomidae Pupillinae Hypselostominae Vertiginidae Pupillidae Pupillinae Valloniidae Acanthinulinae Kimberley coast by Vince Kessner and Alan Longbottom; in the Napier and Oscar Ranges in the south Kimberley by R. A. D. Cameron; and the Gulf of Carpentaria and Cape York Peninsula by L. Price, V. Kessner, and J. Stanisic are referred to in the text, but were received for study too late to be added to the maps. METHODS All distributional records with good locality data were entered into the FLORAPLOT program at the Western Aus- tralian Wildlife Research Centre, Wanneroo, Western Australia. (A hard copy printout of all entered records is located in the Division of Invertebrates, Field Museum of Natural History, Chicago, Illinois.) They were entered to the nearest minute of longitude and latitude if a town, mountain, or homestead was involved or to the nearest second of longitude and latitude if the locality data were more precise, 7.e., a spring, creek bend, isolated hill, dam, or well. Localities such as Roebuck Bay, the type locality of Nesopupa mooreana (E. A. Smith, 1894), and “Murray River,” could not be localized within a minute of latitude and longitude, and thus are not included in the data base. Table 2 Classification used for Australian pupilloid genera. Family Pupillidae Subfamily Nesopupinae Nesopupa Pupisoma Cylindrovertilla Subfamily Gastrocoptinae Gastrocopta Pumilicopta Gyliotrachela Subfamily Pupillinae Pupilla Pupoides Glyptopupoides Maps were printed using a Hewlett-Packard digital plotter. (All printed maps are now located in the Division of Invertebrates, Field Museum of Natural History.) Many maps were designed to indicate broad scale distributions (Figures 2-7, for example), others to show details of di- versity and species sympatry (Figures 9, 11, 13, 14, 27, 28, 31). Judicious selection of compatible symbols for dif- ferent species, such as “+” and “‘O” or “/” and “\”, means that microsympatry to within a second of latitude and longitude appears on the maps as an “®” or an “x”. Species with complex diversity associations or very wide distributions may thus appear on several maps. Other spe- cies may be used as convenient “‘markers” on several maps against which to compare distributions of widely dispersed species whose many overlapping records would make joint display on one map extremely confusing or incomprehen- sible. DISTRIBUTION PATTERNS Some area terms will not be familiar to non-Australian readers. The following definitions should suffice (see Fig- ure 1): Dampierland—Peninsula in Western Australian from Broome to Cape Leveque, ca. 16° to 18°S, 122° to 123°30’E. Kimberley—The northern portion of Western Australia, 13°30’ to 19°S, 123°30’ to 120°E. “Red Centre”—Mountainous parts of Western Australia, South Australia, and Northern Territory, 20° to 26°S, 128? tod3y7ck: “Top End”—Tropical area of the Northern Territory above the Roper River, ca. 10° to 16°S, 129° to 137°E. It is easy to forget that Australia is essentially identical in size to the mainland United States (exclusive of Alaska). Despite the number of records, faunal surveys are still very incomplete. Thus, initial commentary must be made as to the adequacy of distributional data and whether blank spots on a map indicate species absence, collecting absence, or revisionary work absence. Plotted distributions of two genera, Gastrocopta Wol- A. Solem, 1991 Page 239 Gastrocopta deserti X 7 records Gastrocopta ar ganerae + 57 records Gastrocopta wallabyensis 0 4 records 112" 116" 120° 124" 128° 132° Figure 15 Records of Gastrocopta deserti, G. margaretae, and G. wallabyensis in southern Western Australia. laston, 1878 (Figure 6) and Pupordes Pfeiffer, 1854 (Figure 24), illustrate the above points. Pupordes has been recorded from many localities in coastal Queensland and eastern New South Wales, whereas Gastrocopta appears to be ab- sent from these areas. In fact, the material of Gastrocopta from these regions is somewhat limited [except for the introduced G. pediculus (Shuttleworth, 1852)], but the spe- cies have not been revised. Neither genus is present in Tasmania or nearly all of Victoria, nor in the humid southwest corner of Western Australia (except for a few islands). Collecting in these regions has been extensive, so that “genus absence” can be accepted. Neither genus shows extensive records along the west side of the Cape York Peninsula and Gulf of Carpentaria. Collections from these areas made late in 1988 contain both genera, indicating that this was a collecting gap. Gastrocopta macdonnelli x 16 records Gastrocopta macrodon 0 80 records Gastrocopta recondita + 22 records Figure 16 Records of Gastrocopta macdonnelli, G. macrodon, and G. recondita in the Kimberley and “Top End.” Gastrocopta macdonnelli also ranges from Torres Strait to Townsville, Queensland; G. macro- don has been found at Milne Bay, Papua, and in the Louisiade Archipelago; and G. recondita is recorded from the Aru and Ta- nimbar Islands, plus Haruku near Ambon, Indonesia. Ge = a ae em 15° 120° 125° 130° 135° Te 30° + 435° fotrachela australis + 10 records jotrachela catherins o Bireconds jotrachela napierana # records dotrachela ningbingia Xx 38 records Q u| 40 ay 110° 415° 120° 125° 130° 135° Figure 17 Ranges of Gyliotrachela australis, G. catherina, G. napierana, and G. ningbingia in Australia. The interior basins of Western Australia, southwest interior Queensland, and far north of South Australia below the Everard to Tomkinson Ranges are malacolog- ically unexplored and quite probably nearly “snail-free” territory. At most one can expect to find scattered relict colonies. In contrast, the many Flinders Ranges and Eyre Highway associated records reflect both local abundance and many visits by collectors. The above caveats should be kept in mind during all of the following discussions. Generic and Species Ranges A brief discussion of extralimital distributions precedes the description of Australian ranges. The generic sequence follows that of Table 2. 122° 124° 126° 128° 130° 132° 134° 136" 131 Gyliotrachela catherina + 5 records Gyliotrachela napierana 0 8 records Gyliotrachela ningbingia / 38 records Figure 18 Records of Gyliotrachela catherina, G. napierana, and G. ningbingia in the Kimberley and “Top End.” Page 240 415° 120° 125° 130° 135° 140° 145° 150° {ta T T T T T T =n] Ee 10° Ol P 2 20 25" FA 25° 30° 30° Pumilicopta bifurcata xX 47 records Pumilicopta kessneri + 406 records 40° Pumilicopta sp 0 1 records A 9 J ( 40 ————E ! ail {jf 110 415 120 125 130° 435° 140 145 150° 155 Figure 19 Ranges of Pumilicopta bifurcata, P. kessneri, and Pumilicopta sp. in Australia. Nesopupa Pilsbry, 1900, according to the latest world monograph (PILsBRY, 1918-1920:270), has “Distribution: islands of the Pacific, Oriental, and Ethiopian regions, St. Helena... . Inhabiting widely separated island groups, there have been several nearly independent centers of evo- lution, making the construction of a phylogenetic classi- fication exceptionally difficult.” There are two, possibly three, species in northern Australia. Nesopupa mooreana (Figure 2) is very common in the wetter areas of the Kimberley, reaching south to the tip of Dampierland, and was described from Roebuck Bay, near Broome. It is much less common in the ““Top End” of the Northern Territory. Nesopupa novopommerana I. Rensch, 1932 (Figure 3) has been collected near Darwin at a few stations in the Drys- dale River National Park in the Kimberley. Extralimital- ly, it lives in the Tanimbar Islands and Bismarck Archi- pelago. An as yet unidentified Nesopupa has been found 422" 124° 126° 128° 130° 4132" 134° 136° 138° T T =i T T T TT T rT fF Lie a lan = fs 7) ar 122° 124° 126° 428° 130° 132° 134° [pumiiicopta kessneri 0 106 records Figure 20 Records of Pumilicopta kessneri in the Kimberley and “Top End.” The Veliger, Vol. 34, No. 3 115° 120° 125° 130° 135° 140° 145° 150° 10° 15° 20° 25° 30° 35° Pupoides ischnus / 5 records Pupoides lepidulus xX 44 records 0 40° Pupilla australis * 154 records fa y Pupilla ficulnea + 3 records Ww ie . a ——_— = 1 __ . ! ° L 1. 4110 415 120 125 130 4135 140 145° 150° 155° Figure 21 Ranges of Pupilla australis, Pupilla ficulnea, Pupoides ischnus, and Pupoides lepidulus in Australia. in Gulf of Carpentaria and Cape York Peninsula collec- tions, establishing a transnorthern Australia distribution for the genus Nesopupa. Pupisoma Stoliczka, 1873, has about 18 species “‘in trop- ical and subtropical regions of both hemispheres except in arid districts and oceanic islands” (PILSBRY, 1920-1921: 19). Both P. orcula (Benson, 1850) (Figure 4) and P. cir- cumlitum Hedley, 1897 (Figure 5) are common in wet areas from Dampierland across the top of Australia to Pupilla australis + 94 records Figure 22 Records of Pupilla australis in South Australia. A. Solem, 1991 412° 116° 120° 124° 128° 132° Figure 23 Records of Pupilla australis in southern Western Australia. Torres Strait and northern Queensland, with the former much more abundant. They are conspicuously absent from the drier plains areas. An undescribed species, Pupisoma sp. (Figure 5), has been found near Katherine and on Goulburn Island in the Northern Territory, plus the Ningbing Ranges, east Kimberley. Controversy still exists as to whether the New World P. dioscoricola (C. B. Adams, 1845) and the Old World P. orcula are identical or not. A high degree of accidental transport by man has been hy- pothesized for Pupisoma, but the many rain-forest records in northern Australia strongly suggest natural occurrences. Pupisoma is a second transnorthern Australia genus. Cylindrovertilla O. Boettger, 1880, has not been revised since PILSBRY (1920-1921:43-49). Less than five species have been recorded from New Caledonia, south Queens- Figure 24 Records of Pupozdes in Australia. Page 241 20° + 20 25° Fs 0 | 25 + 30° 4 35° Pupoides adelaidae xX 288 records Pupoides beltianus 0 35 records 0 40°F Pupoides pacificus + 242 records ‘ Q 5 le Wy 1 ~ = ML ie IL 1. 1 = 1 1 110 115 120' 125 130 135 140 145° 150" 155° Figure 25 Records of Pupoides adelaidae, P. beltianus, and P. pacificus in Australia. land, and New South Wales. The limits of distribution and the actual number of species are equally uncertain. Gastrocopta probably has the widest natural range of any land snail genus, being “nearly world-wide in tropical and temperate regions, but wanting on many oceanic is- lands and in the recent European fauna, though repre- sented there as Oligocene to Pliocene fossils” (PILSBRY, 1948:871). A few species have been widely disseminated by man, and two of these have reached Australia. Gastro- copta servilis (Gould, 1843), originally from the West In- dies, has been collected near Broome and in Queensland; 20° 435° Pupoides contrarius C 30 records Pupoides eremicolus 0 33 records 0 40° Pupoides ischnus + 5 records fe Q Pupoides myoporinae X 26 records a | 40° ae ha Nhl Id 110° 115° 120° 125° 130 135 140 145 150 155 Figure 26 Records of Pupoides contrarius, P. eremicolus, P. ischnus, and P. myoporinae in Australia. Page 242 Pupoides adelaidae + 224 records Pupoides beltianus Xx 5 records Pupoides myoporinae 0 42 records Figure 27 Records of Pupoides adelaidae, P. beltianus, and P. myoporinae in South Australia. although listed under a variety of names, it is a common introduced species of New Guinea, Indonesia, and on many Pacific Islands (SOLEM, 1989:483-484). Gastrocopta pedic- ulus is the most common Pacific Island species and has been present in Queensland and New South Wales for more than a century, again recorded previously under var- ious names (SOLEM, 1989:486-487). Gastrocopta is the most speciose of the Australian pupil- loid genera, with 11 recognized species, plus two eastern states species, G. strangeana and G. hedleyi, that have not been revised. Extensive collections from the Gulf of Car- pentaria and Cape York Peninsula remain to be studied. Probably additional species will be recognized. Except for the humid southern areas (Figure 6), Gas- trocopta is found throughout Australia. Gastrocopta mar- garetae (Cox, 1868) (Figure 7) is basically south coast; G. deserti (Figure 7) is ““Red Centre” and western Queens- land, but meets G. margaretae in the Flinders Ranges of South Australia (Figure 8), G. pilbarana Solem, 1986 on the west coast (Figure 9), and G. simplex Solem, 1989 (Figure 10) in the Kimberley. There are no other southern species. The “Red Centre” has G. larapinta (Tate, 1896) and G. tate: Pilsbry, 1917 (Figure 11), both of which have a few “dry fringe” records in the Kimberley and “Top End.” The west coast has two species of relatively limited ranges, G. pilbarana and G. wallabyensis (E. A. Smith, 1894) (Figures 9, 12-15). Finally, there are a number of Kimberley-““Top End” species. Gastrocopta simplex (Fig- ures 7, 10) is widely distributed; G. mussoni Pilsbry, 1917 (Figures 10, 32) lives on the desert fringes of the southwest Kimberley and also has been recorded from Mt. Morgan, Queensland; G. macdonnelli (Brazier, 1875) (Figure 16) The Veliger, Vol. 34, No. 3 Pupoides adelaidae 3 4107 records records 19 records Figure 28 Records of Pupoides adelaidae, P. beltianus, P. contraris, P. lepi- dulus, and P. myoporinae in southern Western Australia. lives in coastal areas of the “Top End” and then ranges east to Torres Strait and northern Queensland; G. macro- don Pilsbry, 1917 (Figure 16) is restricted to wetter areas of the Kimberley, then recurs in the Louisiade Archipelago and Milne Bay, Papua; and G. recondita (Tapparone- Canefri, 1883) (Figure 16) lives in dryer portions of the south Kimberley and “Top End,” with an extralimital extension to the Aru and Tanimbar Islands, plus Haruku near Ambon in the Moluccas. The range of Gastrocopta thus covers most of Australia. Gyliotrachela ranges from Burma and Malaya through Indonesia to Timorlaut and the Tanimbar Islands, with a small radiation of four widely separated species in north- ern Australia (Figures 17, 18). All species are strictly limestone associated. The ‘““Top End”’-Kimberley taxa are from drier fringes. Gyliotrachela thus has an interrupted north Australian distribution, mainly from inland dry ar- eas. Pumilicopta Solem, 1989, has species on Sumba and Timor, plus P. kessneri Solem, 1989, in wet areas of the Kimberley and “Top End,” an undescribed species from the Bellenden Ker Ranges, and P. bifurcata Solem, 1989, from scattered areas in Queensland and New South Wales (Figures 19, 20). Additional taxa have been collected re- cently in Cape York and Gulf of Carpentaria regions, thus giving Pumilicopta a transnorthern Australian and eastern states range. Pupilla Leach, 1828, known from various parts of “North America, Eurasia, Africa, Australia, almost wholly in tem- perate and cold regions . . . is a widely distributed group, nowhere numerous in species, but generally abundant in individuals” (PILSBRY, 1948:927). The two Australian spe- cies have very different ranges. Pupilla australis (Adams & Angas, 1864) (Figures 21-23) has a south coast range with isolated records as far north as Carnarvon on the west coast; in the eastern states it reaches northern New South Wales and has been found on some islands in Bass Strait, Tasmania. Pupilla ficulnea (Tate, 1894) is a rare A. Solem, 1991 443° 414° 415° 416° 417° records records records records records aff_adelaidae A beltianus U aff_pbeltianus U contrarius * lepidulus 0 413° 414° 445° 416° Figure 29 Records of Pupoides species and forms in the Shark Bay to North West Cape area of Western Australia. species of limited range in the “Red Centre” (Figure 21). Pupilla thus has a southern range with an isolated species in the seasonally cold “Red Centre.” Pupoides ranges within Australia as widely as Gastro- copta (compare Figures 6 and 24) and is the second most speciose genus of Australian pupilloids, with eight rec- ognized species. Found on “alJ of the continents except Europe” (PILSBRY, 1948:920), ““Pupordes is mainly a trop- ical and subtropical genus of arid regions or of relatively dry stations in humid areas... . The distribution of Pu- poides is remarkably discontinuous ... [and] the absence of the genus in southeastern Asia and East Indies [= In- donesia] leaves the Australian herd profoundly isolated” (PILSBRY, 1920-1921:109). Pupoides pacificus (Pfeiffer, 1846) (Figure 25) has a continuous range of Dampierland to Torres Strait and well into New South Wales (many additional Cape York and Gulf of Carpentaria collections were made in 1988). Pupoides beltianus (Tate, 1894) (Fig- ure 25) has a “Red Centre” to Shark Bay range. Pupoides adelaidae (Adams & Angas, 1864) (Figure 25) is very common between Morawa (northeast of Perth, Western Page 243 Pupoides contrarius 0 Pupoides lepidulus + 5 records 3 records Pupoides myoporinae X 19 records 0 cn 500 , yep . en 36 —L A. Jy 4 14 4 a oe 4 1 i—|___ 1h i 112 116 120 124 128 132° Figure 30 Records of Pupoides contrarius, P. lepidulus, and P. myoporinae in southern Western Australia. Australia) to the Murray River, Victoria. Pupoides eremi- colus (Tate, 1894) (Figure 26) is a “Red Centre” and western Queensland species. Pupoides myoporinae (Tate, 1880) (Figure 26) is a second south coast species, but less common than P. adelaidae and with a shorter range. Pu- pordes lepidulus (Adams & Angas, 1864) (Figure 21) and P. contrarius (E. A. Smith, 1894) (Figure 26) both have central west coast ranges in Western Australia. Finally, P. ischnus (Tate, 1894) (Figures 21, 26) is a rare species of the “Red Centre.” A notable aspect of distribution in Pupoides is that wher- ever species ranges overlap, a dextrally coiled and a sinis- trally coiled species are involved. The sympatric pairs are: Area Dextral species _—_Sinistral species South coast adelaidae Myoporinae West coast lepidulus contrarius “Red Centre” beltianus eremicolus & ischnus The only exception concerns P. pacificus, a dextral species, and the only Pupordes found in northern Australia and the eastern states. One sinistral population of a Pupoides was collected on Cassini Island, Admiralty Gulf, Kimberley in the 1890s (PiLsBRyY, 1920-1921:144), and it was collected again in 1988. Referred to as “form sinistralis” by Pilsbry, its taxonomic status remains to be determined. Glyptopupoides is the only Australian restricted endemic genus. Originally considered to be a land prosobranch, the same species was redescribed by PILSBRY (1922-1926:252- 253) and assigned to a new subgenus of Pupoides, which IREDALE (1937a:304) raised to generic rank in a checklist. Glyptopupoides egregia (Hedley & Musson, 1891) has a remarkable disjunct distribution, with one cluster of rec- ords from the fringes of inland rain-forest patches in the Kimberley (Figure 31), and an extended east coast range (Figure 32). Collecting in the Cape York area has mar- ginally extended its range northwards. The disjunct Kim- berley and Queensland-New South Wales range of Glyp- Page 244 124° 30° 125° 125° 30° 126" 126" 30° 127° 127° 30° 13°30° w ! I | Glyptopupoides egregia X 12 records 14° 30° 414° 30° 45° 15° 30° 16° 30" 424° 124° 30" 425° 125° 30° 126° 426° 30° 127° Figure 31 Records of Glyptopupoides egregia in the Kimberley and “Top End.” topupoides is nearly matched by that of Gastrocopta mussont (Figure 32). The nine genera thus have a few simple patterns of distribution: (1) Only Glyptopupoides is a restricted endemic in Aus- tralia, showing a strikingly disjunct Kimberley and Queensland-New South Wales range (Figure 32); (2) Two genera have regional extralimital ranges: Cy- lindrovertilla is found in New Caledonia and then the Queensland-New South Wales arc; and Pumilicopta has a Sumba and Timor range in Indonesia, followed by a con- tinuous wetter forest range from the Kimberley to Torres Strait and into southern New South Wales (Figure 19); (3) Gylotrachela is characteristic of at least seasonally wet limestone areas from Burma through Indonesia, and has four isolated endemic species scattered across northern Australia (Figure 17); (4) Pupisoma has a pantropical and pansubtropical dis- tribution, some of which may be caused by accidental in- troduction on plants carried about by man—in Australia it has a wet forest transnorthern Australia range (Figures 42)5 (5) Nesopupa ranges from Africa and India to the fur- thest Pacific Islands, with limited wet forest northern Aus- tralian distribution (Figures 2, 3); (6) Pupilla has a disjunct multicontinent distribution, with localized abundance, but not diversity, in temperate and colder regions, which fits its south coast and restricted “Red Centre” range in Australia (Figure 21); and (7) Both Gastrocopta (Figure 6) and Pupoides (Figure 24) are nearly world-wide, but each has a few odd distri- butional gaps. Both genera are found throughout the pupil- loid inhabitable parts of Australia, but not in Tasmania, most of Victoria, or the humid southwest corner of Western Australia. The Veliger, Vol. 34, No. 3 Gastrocopta mussoni + 3 records Glyptopupoides egregia O 34 records ul . ! . 1 . | . | . —ll . 1 110 415 120 125 130 135 140° 145° 150° 155° Figure 32 Ranges of Gastrocopta mussoni and Glyptopupoides egregia in Aus- tralia. Regional Summary On a regional basis, tropical northern Australia from the tip of Dampierland to Torres Strait and then south along the coastal forests of Queensland has the most diverse fauna, with: (1) Pupisoma, Nesopupa, Pumilicopta, Gastro- copta, and Pupoides ranging, at least in wetter areas, across the continent; (2) Gyliotrachela having a scattering of iso- lated species in seasonally dry limestone areas; and (3) Glyptopupoides showing a disjunct Kimberley, then Queensland-New South Wales range. Only the eastern Cylindrovertilla and the cool-temperate genus Pupilla are absent. The at least seasonally wet eastern forests of Queensland and New South Wales, between the Great Dividing Range and the Pacific Ocean, have Pupisoma, Nesopupa, and one limited range species of Glyliotrahela in the north; Glyp- topupoides, Pupoides, Cylindrovertilla, Pumilicopta, and a few Gastrocopta extending well to the south; and limited records of Pupilla extending north along mainly coastal New South Wales from its trans-Australian south coast range. Any given area may have fewer genera present than do the northern fringe sections, but the eastern wet forests include the whole range of pupilloid genera. The south coast, from the New South Wales-South Aus- tralia border to Albany, Western Australia, has only three genera, Gastrocopta, Pupoides, and Pupilla. The “Red Cen- tre” and the west coast of Western Australia from just south of Geraldton to Broome and Dampierland have the same limited group of genera present. Thus, the southern half of Australia, except for a limited extension south in the humid forests of New South Wales, has only three of the nine pupilloid genera. Patterns of species diversity are similar. Four northern A. Solem, 1991 Table 3 Species distribution patterns. NORTHERN AUSTRALIA Wet and intermediate areas (moving west to east) Trans-Australia Pupisoma orcula Pupisoma circumlitum Pupoides pacificus Kimberley only Gastrocopta macrodon Glyptopupoides egregia (also QLD and NSW) Kimberley and “Top End” Nesopupa mooreana Nesopupa novopommerana Pumilicopta kessnert Pupisoma sp. “Top End” and Queensland Gastrocopta macdonnelli Queensland Pumilicopta sp. Gyliotrachela australis Pupisoma orcula (from trans-Australia) Pupisoma circumlitum (from trans-Australia) Gastrocopta mussoni (from dry Kimberley) unrevised Gastrocopta and Pumilicopta Queensland-New South Wales Pumilicopta bifurcata Gastrocopta strangeana Gastrocopta hedleyi Cylindrovertilla spp. Pupoides pacificus (from trans-Australia) Glyptopupoides egregia (also Kimberley) Dry fringes (moving west to east) Kimberley Gastrocopta mussoni (also S QLD) Gastrocopta larapinta (from ““Red Centre’’) Gastrocopta deserti (from “Red Centre’’) Gyliotrachela napierana Gyliotrachela ningbingia Kimberley and “Top End” Gastrocopta simplex Gastrocopta recondita Gastrocopta deserti (from “Red Centre’) “Top End” only Gastrocopta tate: (from “Red Centre’) Gyliotrachela catherina Queensland Gastrocopta deserti (from “Red Centre’) Kimberley and Queensland disjunct Gastrocopta mussonti Glyptopupoides egregia “RED CENTRE” Gastrocopta deserti Gastrocopta tater Gastrocopta larapinta Page 245 Table 3 Continued. Pupoides beltianus Pupoides eremicolus Pupoides ischnus (limited range) Pupilla ficulnea (limited range) WEST COAST anp PILBARA Gastrocopta deserti (from “Red Centre’”’) Gastrocopta pilbarana Gastrocopta wallabyensis Pupoides contrarius Pupoides lepidulus SOUTH COAST ano FLINDERS Gastrocopta deserti (from ‘Red Centre’’) Gastrocopta margaretae Pupilla australis Pupoides adelaidae Pupoides myoporinae Australian species have extralimital ranges. Pupisoma or- cula extends at least to southeast Asia and may be circum- tropical; Nesopupa novopommerana has been collected on the Tanimbar Islands and New Britain, Bismarck Archi- pelago; Gastrocopta macrodon is restricted to the wet Kim- berley, but then appears at Milne Bay, Papua, and in the Louisiade Archipelago; and G. recondita, from the dry south fringes of the Kimberley and “Top End,” also lives in the Aru and Tanimbar Islands plus on Haruku near Ambon in the Moluccas, Indonesia. Only two species show notable disjunctions within Aus- tralia. Gastrocopta mussoni has been recorded from two localities in the desert fringes of the south Kimberley and also from Mt. Morgan, Queensland. Glyptopupoides egre- gia has a fairly wide distribution on the fringes of mainly inland rain-forest patches in the Kimberley and an exten- sive Queensland-New South Wales range. The general patterns of species distributions are sum- marized in Table 3. Nineteen of the 32 named species are present in some part of the Kimberley and “Top End,” with a distinct difference between the dry fringes and the northern wetter zones. In contrast, the ““Red Centre” has only seven species. The south coast and west coast each have four endemics plus an intrusion of Gastrocopta deserti from the “Red Centre.” Data are inadequate to charac- terize the pupilloid fauna from the wet forests of Queens- land and New South Wales, although that fauna is ge- nerically diverse and with at least a modest species radiation. LOCAL DIVERSITY PATTERNS Although recent collections from the Gulf of Carpentaria fringes and Cape York region have filled in a major col- lecting gap and provided many sympatric records, data from that survey are not available for interpretation at this time. Historic records from the literature cannot be de- pended upon for an accurate depiction of sympatry, and The Veliger, Vol. 34, No. 3 Table 4 Pupilloid species in Kimberley wet areas. Page 246 Island samples (n = 91) Species Number Percent Gastrocopta macrodon 74 81.3 Gastrocopta simplex 9 9) Glyptopupoides egregia 2 D8? Nesopupa mooreana 48 52a, Pupisoma circumlitum 9 9.9 Pupisoma orcula 32 35.2 Pupoides pacificus 26 28.6 Pumilicopta kessneri 38 41.8 thus comments on the Queensland-New South Wales pat- terns must be deferred. Preliminary review of the new collections suggests that local diversity rarely reaches four species and that distribution is patchier than in the Kim- berley. Both the south and west coasts of Australia have a limited fauna (Table 3). Both areas have fringe records of the “Red Centre” species Gastrocopta desert: (Figures 8, 9, 14, 15), sometimes involving microsympatry with other Gastrocopta. The south coast has four species with rather wide ranges: (1) Pupilla australis (Figure 21) is more coast- al and extends to the coast of New South Wales; (2) Gas- trocopta margaretae (Fig. 7) inhabits much of the Flinders Ranges, but does not extend as far east or west as does Pupilla australis; (3) Pupoides adelaidae (Figure 25) extends further inland and westward; and (4) Pupoides myoporinae (Figure 26), which is much less abundant, has a less ex- tensive range, and is absent from much of the Eyre Pen- insula. The two species of Pupozdes show occasional sym- patry in South Australia (Figure 27), but P. adelazdae is much more abundant and widely distributed. In Western Australia (Figure 28), most records of P. myoporinae in- volve sympatry with P. adelaidae. In coastal and Eyre Highway sections, sympatry of all four species is not un- usual, with inland records showing loss of the more coastal taxa. Pupilla australis (Figures 22, 23) has inland records in South Australia but mainly coastal records in Western Australia. Interpretation of west coast records is premature, be- cause many collections consist only of sifted drift material, and thus potentially represent mixed habitat information. Records are few in number, reflecting both the harsh hab- itat and the comparatively limited collecting done in this region. From Shark Bay to just north of the North West Cape, there are four Pupoides (Figure 29) recognized (see SOLEM, 1986:107-115): Pupoides lepidulus (Figure 21) and P. contrarius (Figure 26), both restricted endemics; an ap- parent intrusion of the ““Red Centre” species P. beltianus (Figure 25); and a very few records of the south coast P. adelaidae. The endemics (Figures 28, 30) often are micro- sympatric. The otherwise southern species Pupilla australis (Figure 23) is known from a single record at Point Quobba, Coastal samples (n = 35) Inland samples (n = 31) Number Percent Number Percent 27 Viel 20 64.5 1 2.9 5 16.1 2 Sei 8 25.8 28 80.0 20 64.5 3 8.6 10 323 25 71.4 23 74.2 12 34.3 12 38.7 34 97.1 18 58.1 north of Carnarvon. Gastrocopta is represented by a few species. Several records are known for the “Red Centre” species G. deserti (Figures 9, 14, 15); and two endemic species, G. wallabyensis and G. pilbarana (Figures 13-15), have limited records, with occasional microsympatry. Much more collecting is needed in this region. The ‘Red Centre” has a slightly more extensive radi- ation, showing a mixture of very common and widely distributed species (Gastrocopta deserti, Figure 7; Pupoides beltianus, Figure 25; P. eremicolus, Figure 26), widely dis- tributed, but clearly disjunct taxa (G. tatez, Figures 11, 12; G. larapinta, Figure 11), and two species of very limited “Red Centre” distribution (Pupilla ficulnea, Figure 21; Pupoides ischnus, Figures 12, 21). All of the species have been collected from stream drift or fig litter near Glen Helen (WA-113), MacDonnell Ranges, and in Palm Valley (WA-130, WA-131), Kri- chauff Ranges. All of these localities lie in the Finke River drainage. The relative abundance of the three species of Gastrocopta varies greatly from locality to locality (SOLEM, 1989:490). Once the wetter mountains are left, the number of microsympatric species declines. Pupilla ficulnea and Pupoides ischnus are restricted to the central area (Figure 21). The dextral species Pupoides beltianus (Figure 25) is common from the Jervois Range, northeast of Alice Springs, to the Barrow Range in Western Australia, with a prob- able extension to the Shark Bay area (Figure 29). The sinistral Pupoides eremicolus (Figure 26) has been collected at Boulia, Black Mt., and Saxby Downs Homestead in western Queensland, then from Tennant Creek and the Dulcie Range through the Krichauff Ranges; it has not been collected in Western Australia. Gastrocopta deserti (Figure 7) has a significant set of western Queensland records, inhabits northern parts of the Flinders Ranges, where it has one microsympatric record with G. margaretae (Figure 8), is common in the Everard and Mann Ranges (Figure 8), reaches the south fringes of the Kimberley, and near Katherine in the Northern Territory (Figure 10), and then the west coast between Point Quobba and Dampierland (Figures 9, 14, 15). Gastrocopta tate: (Figure 11) partly overlaps the range of G. larapinta in the “Red Centre,” but extends farther west and has an isolated A. Solem, 1991 Page 247 Table 5 Species diversity in Kimberley wet areas. Island samples Number of species Number Percent 0 10 11.0 1 20 22.0 2 14 15.4 3 18 19.8 4 14 15.4 5 10 11.0 6 5 eee) 7 0 0.0 TOTALS 91 100.1 Mean number of species/sample 2.62 record near Elsey Falls, Roper River, “Top End.” Gas- trocopta larapinta extends farther east into the Dulcie and Jervois Ranges (Figure 11) and then appears in Brooking Gorge, Oscar Ranges, Western Australia, plus a more northern locality, the Carson Escarpment. Thus, only two species, Pupoides ischnus and Pupilla ficulnea, are restricted to the ““Red Centre.” The other five show varying patterns of presence in other parts of Aus- tralia. In wetter refugia of the “Red Centre,” most pupilloid species can be found in the litter under a single small patch of figs. The Kimberley and “Top End” have the largest number of species and the most complex patterns of local diversity. A basic area differentiation must be made on moisture patterns. The Darwin to Gulf of Carpentaria part of the “Top End” and the Prince Regent River to Kalumburu part of the northwest Kimberley have 1000-1500 mm wet seasons. The area near Katherine, Northern Territory, the area along the border from Sir Joseph Bonaparte Gulf inland to Halls Creek, and the chain of Devonian limestone reefs from the Napier Range southeast through the Eman- uel and Lawford Ranges have only a 500-759 mm wet season. The two coastal and slightly inland wet regions thus grade into drier and eventually inland desert regions to the south. In addition, they are separated by a trough of land with reduced rainfall that extends along the West- ern Australia-Northern Territory (WA-NT) border. Each section of this region has its own peculiarities of faunal composition and diversity patterns. Distributional data on the “Top End” sections are based upon several sources: collections made by Vince Kessner, as reported in SOLEM (1989:468-516); collections from the “dry trough of the WA-NT border area” made by the author and reported on in SOLEM (1988:71-74); collections from the limestone fringes of the south Kimberley by A. Solem in 1976-1985 and R. Cameron in 1988; and the Kimberley wet area collections primarily by Vince Kessner during the Rain- > Coastal samples Inland samples Number Percent Number Percent 0 0.0 2 6.5 2 Beal 2 6.5 2 5.7 3} 9.7 11 31.4 4 12.9 12 34.5 8 25.8 6 17.1 8 25.8 1 2.9 4 12.9 1 2.9 0) 0.0 35 100.0 31 100.0 3.74 3.74 forest Survey of June 1987 (reported on in SOLEM, in press) and the Kimberley Coast Expedition of June and July 1988 (data summarized here). Fringe intruders from other regions number seven: Ne- sopupa novopommerana (Figure 3) from near Darwin and the Drysdale River, then Tanimbar Islands and New Brit- ain, Bismarck Archipelago; Gastrocopta macdonnelli (Fig- ures 11, 16) from Darwin and Melville Island east to Torres Strait and south at least to Townsville, Queensland; Gastrocopta deserti, G. tatei, and G. larapinta, all from the “Red Centre” (Figures 10, 11); Gastrocopta mussoni (Fig- ures 3, 32), described from near coastal Queensland; and Glyptopupoides egregia (Figures 31, 32) from Queensland and northern New South Wales, and then mainly inland parts of the Kimberley wet area. The wet portion of the ‘““Top End” has a typical assem- blage of Pupisoma orcula, Pupisoma circumlitum, Pumili- copta kessnert, Nesopupa mooreana, and Gastrocopta mac- donnelli (near the coast) or G. simplex (more inland). Dry inland areas will tend to have Gastrocopta recondita (oth- erwise an Indonesian species), Pupoides pacificus, G. sim- plex (or G. deserti, G. tatei, etc.), and (on limestone) Gy- liotrachela catherina, but will be without some of the wetter area taxa. There thus is a common pattern of three to five microsympatric species. The zone along the WA-NT border has many limestone hills that, in general, hold large land snail populations. In the wetter northern area of the Ningbing Ranges and Jeremiah Hills, the restricted endemic Gyliotrachela ning- bingia (Figures 17, 18) and Gastrocopta simplex (Figures 7, 10) are nearly ubiquitous (see SOLEM, 1988:90, 94), while Pupoides pacificus (Figure 25; SOLEM, 1988:97) is much less common. There are one to three records each for Pupisoma orcula, Pupisoma sp., and Nesopupa mooreana from swamp adjacent to the Ningbing Ranges. Further inland, there are only records of Gastrocopta simplex, Pu- poides pacificus, and occasionally G. desert: or G. recondita. A pattern of two or three microsympatric species is typical. Page 248 Along the limestone hills that border the south margin of the Kimberley, there is a clear pattern of gradual re- duction in species diversity from the wetter northwest cor- ner (750 mm) to the much drier Lawford Ranges (550 mm). Rainfall records are not adequate to provide cor- relations, but the general pattern is simple. In the north- west Napiers, Gastrocopta macrodon (a wet Kimberley tax- on at its southern limit), G. recondita (a south fringes species at its northern Australian limit), sometimes G. simplex (a dry Kimberley-““Top End” species), Pupozdes pacificus (a dry zone transcontinental north Australian species), and Gyliotrachela napierana (Figures 17, 18; a restricted endemic in the northwest Napier Range) can be present. This gives a four to five microsympatric species pattern. Gastrocopta macrodon has a sporadic range, from the Van Emmerick Range to Stumpy’s Well, then reap- pearing about 2—4.7 km south of Yammera Gap, and again near the Lillimilura Police Station ruins. Gastrocopta re- condita and Pupoides pacificus continue throughout the limestone hills, and Gastrocopta simplex becomes more abundant to the southeast. Gyliotrachela napierana extends southeast to Barker Gorge and then reappears briefly in a highly dissected set of hills about 2.3-2.4 km south of Wombarella Gap and at the “Dingo Caves” some 10.6 km south of Yammera Gap. From here to Brooking Gorge in the Oscar Ranges, the number of pupilloid species is usually only two or three—Gastrocopta recondita and/or G. simplex, and Pupoides pacificus. In Brooking Gorge, there are isolated records for Gastrocopta larapinta, and G. mussont has been collected near the Brooking Spring Sta- tion air strip, increasing the degree of local diversity. Southeast of the Oscar Range, there are only scattered records for G. simplex and P. pacificus. Thus, diversity along the south fringe of the Kimberley shifts from five to two species along a northwest to south- east axis. This correlates with a similar gradient of decrease in wet season rainfall. The greatest numbers of species and genera, plus the highest levels of local diversity, are found in the wet areas of the northwest Kimberley (see Tables 4, 5). Two com- prehensive field surveys provided directly comparable data on local diversity in relation to habitat and area history, permitting observations on local diversity shifts. The Rain- forest Survey of June 1987 focused on a broad sampling of vine thicket patches throughout the Kimberley, making 82 stations in 20 field days. Their sampling included very few stations from islands, because the helicopter used in this survey was not equipped with over-water safety equip- ment. In June and July 1988, a joint Western Australian Museum-Australian Museum-Field Museum of Natural History expedition visited 84 islands off the Kimberley Coast using the chartered vessel North Star and made 115 collecting stations. A very few of the stations from the two trips overlapped. The Veliger, Vol. 34, No. 3 Of the pupilloid species previously collected in the Kim- berley and reported on by SOLEM (1989), only Nesopupa novopommerana, from inland portions of the Drysdale Riv- er National Park, was not obtained by the two survey teams. The only possibly additional species obtained were: (1) asmall series of dead Gastrocopta from near Kalumburu (SOLEM, in press) that may represent an unknown species or may be subadults of a known species and (2) a recol- lected, sinistral Pupoides from Cassini Island that probably is distinct. ACKNOWLEDGMENTS Field work that provided the materials used in this study was sponsored by National Science Foundation grants DEB 75-20113, DEB 78-21444, BSR 81-19208, BSR 83-12408, and BSR 85-00212 to Field Museum of Natural History, Alan Solem, Principal Investigator, supplemented by gen- erous gifts from Mr. and Mrs. Arthur T. Moulding. Col- lections from the Kimberley in 1987 and 1988 by Field Associate Vince Kessner and along the Gulf of Carpentaria and on the Cape York Peninsula by Field Associates Lau- rie Price and V. Kessner, plus Alan Longbottom of Grass Patch, Western Australia, John Stanisic and Darry] Potter of the Queensland Museum, Brisbane, were sponsored in major part by the Marshall Field Fund, Field Museum of Natural History. The generosity of the late Frederick K. Leisch who provided the Toshiba T250 computer on which this paper was written is greatly appreciated. Much help with the processing of specimens and initial data organization was provided by Field Museum of Nat- ural History staff members Beth S. Morris, Victoria B. Huff, and Margaret Baker. For permission to study material in collections under their charge, I am indebted to Winston Ponder, Australian Museum, Sydney; C. C. Lu, Museum of Victoria, Mel- bourne; John Stanisic, Queensland Museum, Brisbane; Wolfgang Zeidler and Karen Gowlett-Holmes, South Australian Museum, Adelaide; Shirley Slack-Smith and Fred E. Wells, Western Australian Museum, Perth; Fred Aslin, Mount Gambier, South Australia; and Vince Kes- sner, Adelaide River, Northern Territory. All records were entered into the FLORAPLOT program at the Western Australian Wildlife Research Centre, Wannero, Western Australia, through the courtesy of Dr. Andrew Burbidge, Principal Research Officer. The assis- tance of Paul Gioia, Wildlife Research Centre, who de- veloped the program, taught me how to operate it, and supervised the entry of my data base is gratefully acknowl- edged. Final editing of the FLORAPLOT maps for publication was done by Victoria B. Huff. A. Solem, 1991 APPENDIX 1 List of Reviewed Australian Pupilloid Taxa * Indicates an introduced species. Genus Gastrocopta Wollaston, 1878 (Synonyms: Australbinula Pilsbry, 1916; Gyrodaria Iredale, 1940; Papualbinula Iredale, 1941) Gastrocopta deserti Pilsbry, 1917 Synonym: helmsiana Iredale, 1939. See SOLEM, 1986:102-103, figs. 13-15; SOLEM, 1989: 487-489, figs. 48-53. Type locality: “Red Centre,” Australia. Gastrocopta larapinta (Tate, 1896) See SOLEM, 1989:490-491, figs. 54-55. Type locality: “Red Centre,” Australia. Gastrocopta macdonnelli (Brazier, 1875) See SOLEM, 1989:492-493, figs. 60-61. Type locality: Fitzroy Island, NE Queensland. Gastrocopta macrodon Pilsbry, 1917 See SOLEM, 1989:495-496, figs. 62-67. Type locality: Milne Bay, Papua, New Guinea. Gastrocopta margaretae (Cox, 1868) Synonyms: bannertonensis Gabriel, 1930; complexa Ire- dale, 1939. See SOLEM, 1986:99-101, figs. 1-10. Type locality: Wallaroo, South Australia. Gastrocopta mussoni Pilsbry, 1917 See SOLEM, 1989:494, figs. 211-213. Type locality: Calliungal (= Mt. Morgan), SE Queens- land. *Gastrocopta pediculus (Shuttleworth, 1852) See SOLEM, 1989:486-487, figs. 46-47. Type locality: Marquesas Islands. Comment: Probably of Indonesian origin. Gastrocopta pilbarana Solem, 1986 See SOLEM, 1986:103-104, figs. 16-20. Type locality: Sandy Point, Dirk Hartog Island, Shark Bay, Western Australia. Gastrocopta recondita (Tapparone-Canefri, 1883) Synonym: niobe Fulton, 1899. See SOLEM, 1989:496-497, figs. 73-78. Type locality: Wokan, Aru Islands. *Gastrocopta servilis (Gould, 1843) Synonyms: microsoma Tapparone-Canefri, 1883: lyon- stana Ancey, 1892. See SOLEM, 1989:483-484, figs. 38-41. Type locality: near Matanzas, Cuba. Comment: Of West Indian origin, introduced on plants. Page 249 Gastrocopta simplex Solem, 1989 See SOLEM, 1989:484-486, figs. 42-45. Type locality: Pentecost River, El] Questro Homestead, SW of Wyndham, Western Australia. Gastrocopta tate: Pilsbry, 1917 See SOLEM, 1989:491-492, figs. 56-59. Type locality: Central Australia. Gastrocopta wallabyensis (E. A. Smith, 1894) See SOLEM, 1986:101-102, figs. 11-12. Type locality: E Wallaby Island, Houtman Abrolhos group, Western Australia. Genus Glyptopupoides Pilsbry, 1926 (Synonym: Famarinia Iredale, 1933) Glyptopupoides egregia (Hedley & Musson, 1891) Synonym: hedley: Pilsbry, 1926. See SOLEM, 1989:506-508, figs. 214-217. Type locality: Calliungal (= Mt. Morgan), Queensland. Genus Gyliotrachela Tomlin, 1930 (Synonyms: Gyliauchen Pilsbry, 1917 [non Nicoll, 1915]; Gylotrachela Pilsbry, 1931) Gyliotrachela australis (Odhner, 1917) See SOLEM, 1981:92, figs. 7, 8, 12. Type locality: Chillagoe Caves, N Queensland. Gyliotrachela catherina Solem, 1981 See SOLEM, 1981:91-92, figs. 5, 6, 11, 17; SOLEM, 1989: 504-505, figs. 97-102. Type locality: 19 km S of Katherine, Northern Terri- tory. Gyliotrachela napierana Solem, 1981 See SOLEM, 1981:91, figs. 3, 4, 10, 14-16, 18, 19; SOLEM, 1989:503-504, figs. 94-96. Type locality: 5.7 km N of No. 8 Bore, Ningbing Rang- es, N of Kununurra, Western Australia. Genus Nesopupa Pilsbry, 1900 (Synonym: Westralcopta Iredale, 1939) Nesopupa mooreana (E. A. Smith, 1894) See SOLEM, 1989:477-479, figs. 33-37. Type locality: Roebuck Bay, Western Australia. Nesopupa novopommerana I. Rensch, 1932 Synonym: tenimberica Haas, 1937. See SOLEM, 1989:476-477, figs. 27-32. Type locality: Karlei, Weite Bucht, Neu-Pommerm (= New Britain), Bismarck Archipelago. Genus Pumilicopta Solem, 1989 Pumilicopta bifurcata Solem, 1989 See SOLEM, 1989:497-498, figs. 88-90. Type locality: Mountain near Bouldercome, central Queensland. Page 250 Pumilicopta kessnert Solem, 1989 See SOLEM, 1989:499-500, figs. 85-87. Type locality: Wunyu Beach, West Arnhem Land, Northern Territory. Pumilicopta sp. See SOLEM, 1989:498. Locality: Westgid Creek, Bellenden Ker Range, north- east Queensland. Genus Pupilla Leach, 1828 (Synonym: Omegapilla Iredale, 1937) Pupilla (Gibbulinopsis) australis (Adams & Angas, 1864) Synonyms: lincolniensis Cox, 1867; occidentalis Iredale, 1939. See SOLEM, 1986:105-107, figs. 21-24. Type locality: Fleurieu Peninsula, South Australia. Pupilla (Gibbulinopsis) ficulnea (Tate, 1894) See SOLEM, 1989:505-506, figs. 103-104. Type locality: Central Australia. Genus Pupisoma Stoliczka, 1873 (Synonym: /mputegula Iredale, 1937) Pupisoma circumlitum Hedley, 1897 See SOLEM, 1989:473-474, figs. 17, 24, 25. Type locality: Bundaberg, Queensland. Pupisoma orcula (Benson, 1850) See SOLEM, 1989:472-473, figs. 18, 21-23. Type locality: Between Jounpore and Benares, India. Pupisoma sp. See SOLEM, 1989:475, figs. 16, 26. Locality: Scattered Northern Territory records and Ningbing Ranges, Western Australia. Genus Pupoides Pfeiffer, 1854 (Synonymy: Themapupa Iredale, 1930) Pupoides adelaidae (Adams & Angas, 1864) Synonyms: ramsay: Cox, 1864; asserta Iredale, 1939; contexta Iredale, 1939; amolita Iredale, 1940. See SOLEM, 1986:111-113, fig. 31. Type locality: South Australia. Pupoides aff. adelaidae (Adams & Angas, 1864) See SOLEM, 1986:114-115, figs. 32-33. Locality: Shark Bay and slightly north, Western Aus- tralia. Pupoides beltianus (Tate, 1894) See SOLEM, 1989:511-513, fig. 107. Type locality: Central Australia. Pupoides aff. beltianus (Tate, 1894) See SOLEM, 1986:114, fig. 36. Locality: Shark Bay to North West Cape and Ham- ersley Range, Western Australia. The Veliger, Vol. 34, No. 3 Pupoides contrarius (E. A. Smith, 1894) See SOLEM, 1986:109-111, figs. 27, 28. Type locality: East Wallaby Island, Houtman Abrolhos, Western Australia. Pupoides eremicolus (Tate, 1894) See SOLEM, 1989:509-511, fig. 106. Type locality: Central Australia. Pupoides ischnus (Tate, 1894) Synonym: /atior Iredale, 1937. See SOLEM, 1989:508-509, fig. 105. Type locality: Central Australia. Pupoides lepidulus (Adams & Angas, 1864) See SOLEM, 1986:113-114, fig. 34. Type locality: Shark Bay, Western Australia. Pupoides myoporinae (Tate, 1880) Synonym: sinistrorsus Tate, 1879 [non Serres, 1841]. See SOLEM, 1986:108-109, figs. 25, 26. Type locality: Peelunbie, Head of the (Great Austra- lian) Bight, South Australia. Pupoides pacificus (Pfeiffer, 1846) Synonyms: anapacifica Iredale, 1939; dirupta Iredale, 1939; comperta Iredale, 1940. See SOLEM, 1989:513-516, figs. 108-114. Type locality: Sir Charles Hardy’s Island, Cape York Peninsula, Queensland. List of Unrevised Pupilloid Taxa The following taxa listed in the nomenclatural checklist of IREDALE (1937a:301-306) have not been reviewed for lack of adequate material. It is possible neither to char- acterize them adequately as species nor to delineate mean- ingful distributional ranges. References are given both to IREDALE (1937a) and the early revisions by PILSBRY (1916- 1918, 1920-1921). Comments are given where appropri- ate. Gastrocopta hedley: Pilsbry, 1917 See PILsBRY, 1916-1918:166-167, pl. 27, figs. 1-4; IRE- DALE, 1937a:301. Type locality: Narrabri, New South Wales. Comment: A dextral shell with a huge, slanted colu- mellar barrier whose anterior end is lower; parietal long and crescentic; basal tiny and tubercular; lower palatal strongly angled. Gastrocopta macleayi (Brazier, 1876) See PILsBRY, 1916-1918:162-164, pl. 27, fig. 9; IRE- DALE, 1937a:302. Type locality: Bet and Sue Islands, Torres Strait, Queensland. Comment: Probably a synonym of G. macdonnelli (Bra- zier, 1875). A. Solem, 1991 Gastrocopta moretonensis (Cox, 1868) See Piussry, 1916-1918:161-162, pl. 26, figs. 12, 13; IREDALE, 1937a:301. Type locality: Moreton Bay, Queensland. Comment: Type specimens probably lost, no topotypes seen; original illustration inadequate for identification purposes. Gastrocopta queenslandica Pilsbry, 1917 See Piussry, 1916-1918:159-160, pl. 26, fig. 2; IRE- DALE, 1937a:301. Type locality: Calliungal (= Mt. Morgan), Queensland. Comment: The type illustration looks like a “new adult” of G. pediculus (Shuttleworth, 1852) in which the apertural barriers are still undersized. Gastrocopta rossiteri (Brazier, 1875) See Piussry, 1916-1918:147; IREDALE, 1937a:302. Type locality: Picton, New South Wales. Comment: Probably based upon examples of G. pedicu- lus (Shuttleworth, 1852). Gastrocopta strangeana Iredale, 1937 Synonym: strange: Pfeiffer, 1854, non Benson, 1853. See PinsBry, 1916-1918:157-158, pl. 26, figs. 3-6; IRE- DALE, 1937a:301. Type locality: Gordon (= Garden) Island, Port Jackson, New South Wales. Comment: A sinistral shell with the parietal and angular barriers well separated; columellar barrier simple and not inclined; basal a tiny knob; lower palatal crescen- tic; upper palatal a medium-sized knob. The only sinistral Australian Gastrocopta. IREDALE (1940:234) proposed a new genus, Gyrodaria, for this species. Gastrocopta strangeana trita (Iredale, 1940) See IREDALE, 1940:233-234, fig. 3. Type locality: Narrabri, New South Wales. Comment: A “larger sinistral form” of G. strangeana is the only differentiating phrase. Probably a nomen nu- dum. Genus Cylindrovertilla Boettger, 1880 (Synonym: Wallivertilla Iredale, 1937) Comment: Minute, sinistral shells, recorded from New Caledonia and the Queensland-New South Wales arc; mainly coastal areas. Parietal barrier has been lost, but a prominent angular barrier remains. Cylindrovertilla fabreana boynensis Iredale, 1937 See Pitssry, 1916-1918:47-48, pl. 5, figs. 12, 13; IRE- DALE, 1937a:303. Type locality: Boyne Island, Port Curtis, Queensland. Cylindrovertilla hedley: Pilsbry, 1920 See PILsBry, 1920-1921:46, pl. 5, figs. 4, 10; IREDALE, 1937a:303. Type locality: Calliungal (= Mt. Morgan), Queensland. Comment: Lower palatal barrier lost, others reduced in size. Page 251 Cylindrovertilla kingi (Cox, 1864) See Pitssry, 1920-1921:44-46, pl. 5, figs. 1-3; IRE- DALE, 1937a:303. Type locality: Paramatta, New South Wales. Comment: Two palatal barriers present. Cylindrovertilla kingi negata Iredale, 1940 See IREDALE, 1940:233, 235, fig. 2. Type locality: Tweed River, New South Wales. Comment: Probably a synonym of C. king: (Cox, 1864). Pupilla nelsoni (Cox, 1864) See PILsBRY, 1920-1921:219-220—as synonym of P. australis [Adams & Angas, 1864]; also see IREDALE, 1937a:304. Type locality: Nelson’s Bay, Sydney, New South Wales. Comment: Probably a synonym of P. australis. Pupilla tasmanica (Johnston, 1883) See PILsBry, 1920-1921:219-221, pl. 23, fig. 18—as synonym of P. australis [Adams & Angas, 1864]; also see IREDALE, 1937a:305. Type locality: Tasmania. Comment: Probably a synonym of P. australis. Genus Somniopupa Iredale, 1937 Comment: Quite probably a nomen nudum. Somniopupa scotti Brazier, 1875 See PiusBry, 1920-1921:222, pl. 23, fig. 22; IREDALE, 1937a:305. Type locality: Fitzroy Island, Queensland. Comment; Based on a single, probably juvenile example. Very probably a synonym, but its identity remains uncertain. LITERATURE CITED BisHop, M. J. 1981. The biogeography and evolution of Aus- tralian land snails. Pp. 923-954. In: A. Keast (ed.), Ecolog- ical Biogeography of Australia. Vol. 2. W. Junk: The Hague, Netherlands. IREDALE, T. 1930. Notes on some Desert Snails. Victorian Naturalist 47(7):118-120. IREDALE, T. 1933. Systematic notes on Australian land shells. Records of the Australian Museum 19:37-59. IREDALE, T. 1937a. A basic list of the land Mollusca of Aus- tralia. Australian Zoologist 8(4):287-333. IREDALE, T. 1937b. An annotated check list of the land shells of south and central Australia. South Australian Naturalist 18(1-2):6-59. IREDALE, T. 1939. A review of the land Mollusca of Western Australia. Journal of the Royal Society of Western Australia 25:1-88. IREDALE, T. 1940. Guide to the land shells of New South Wales. The Australian Naturalist 10:227-236. IREDALE, T. 1941. A basic list of the land Mollusca of Papua. Australian Zoologist 10(1):51-94. McMIcHAEL, D. F. & T. IREDALE. 1969. The land and fresh- water Mollusca of Australia. Pp. 224-245. In: A. Keast et al. (eds.), Biogeography and Ecology in Australia. Mono- graphiae Biologicae 8. W. Junk: The Hague, Netherlands. Page 252 Pitsspry, H. A. 1916-1918. Manual of Conchology, 2nd series 24:i-xii, 1-380. Pitspry, H. A. 1920-1921. Manual of Conchology, 2nd series 25:i-ix, 1-401. PitsBry, H. A. 1922-1928. Manual of Conchology, 2nd series 27:i-iv, 1-369. Piussry, H. A. 1934-1935. Manual of Conchology, 2nd series 28:i-xii, 97-226. PiusBry, H. A. 1948. Land Mollusca of North America (north of Mexico). Monographs of The Academy of Natural Sci- ences of Philadelphia 3, 2(2):521-1113. SMITH, B. J. 1985. Recording the land mollusc fauna of South Australia. Pp. 341-346. In: J. M. Lindsay (ed.), Stratig- raphy, Palaeontology, Malacology. Papers in Honour of Dr. Nell Ludbrook. Department of Mines and Energy, South Australia. Special Publication 5:1-387. SMITH, B. J. & R. C. KERsHAW. 1979. Field Guide to the Non-Marine Molluscs of South Eastern Australia. Austra- lian National University Press: Canberra, Australia. i—x, 1- 285 pp. SMITH, B. J. & R. C. KersHaw. 1981. Tasmanian Land and Freshwater Molluscs. Fauna of Tasmania Handbook No. 5:1-148. SOLEM, A. 1978. Classification of the land Mollusca. Pp. 49- 97. In: V. Fretter & J. Peake (eds.), Pulmonates, Vol. 2A, Systematics, Evolution and Ecology. Academic Press: Lon- don. SOLEM, A. 1981. Small land snails from Northern Australia. I. Species of Gyliotrachela Tomlin, 1930 (Mollusca: Pul- monata: Vertiginidae). Journal of the Malacological Society of Australia 5:87-100. SOLEM, A. 1986. Pupilloid land snails from the south and The Veliger, Vol. 34, No. 3 midwest coasts of Australia. Journal of the Malacological Society of Australia 7(3-4):95-124. SOLEM, A. 1988. Maximum in the minimum: biogeography of land snails from the Ningbing Ranges and Jeremiah Hills, northeast Kimberley, Western Australia. Journal of the Malacological Society of Australia 9:59-113. SOLEM, A. 1989. Non-camaenid land snails of the Kimberley and Northern Territory, Australia I. Systematics, affinities and ranges. Invertebrate Taxonomy 2(4):455-604. SOLEM, A. In press. Land snails of Kimberley rainforest patches and biogeography of all Kimberley land snails. In: N. L. McKenzie, R. B. Johnston & P. G. Kendrick (eds.), Tropical Rainforests of the Kimberley, Western Australia: Ecology and Biogeography. Department of Conservation and Land Management: Perth. SOLEM, A. & N. L. McKenzie. In press. Biogeographical patterns of land snail assemblages in Kimberley rainforests. In: N. L. McKenzie, R. B. Johnston & P. G. Kendrick (eds.), Tropical Rainforests of the Kimberley, Western Aus- tralia: Ecology and Biogeography. Department of Conser- vation and Land Management: Perth. SOLEM, A. & E. YOCHELSON. 1979. North American Paleozoic land snails, with a summary of other Paleozoic nonmarine snails. U.S. Geological Survey Professional Paper 1072:i- iii, 1-42. TILLIER, S. 1989. Comparative morphology, phylogeny and classification of land snails and slugs (Gastropoda: Pulmona- ta: Stylommatophora). Malacologia 30(1-2):1-303. ZILCH, A. 1959. Gastropoda. Teil 2. Euthyneura. Handbuch der Paldozoologie, 6, Liefereung 1:1-200. The Veliger 34(3):253-258 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Terrestrial Snails (Gastropoda) in Dominican Amber GEORGE O. POINAR, JR. AND BARRY ROTH Department of Entomological Sciences, University of California, Berkeley, California 94720, and Museum of Paleontology, University of California, Berkeley, California 94720, USA Abstract. Seven species of land snails are reported from amber of late Oligocene (25 Ma) to late Eocene (40 Ma) age from the Dominican Republic: Strobilops (?Coelostrobilops) sp.; Subulina sp.; Spiraxis sp.; ?ferussaciid, genus and species indeterminate; Varicella sp.; helicinid, genus and species indeter- minate; and a prosobranch land snail of indeterminate family. As far as determinable, all are within the modern geographic ranges of their taxonomic groups. The taxa are indicative of a tropical or paratropical climate. Strobilopsidae assignable to modern genera and subgenera may have been present in the American tropics at least as early as in western Europe. INTRODUCTION Fossil remains of terrestrial snails (Gastropoda: Pulmona- ta and Prosobranchia) in amber are relatively rare. Shells identified as species of Electrea (?Cyclophoridae), Strobilus (= Strobilops; Strobilopsidae), Vertigo (Pupillidae), Balea (Clausiliidae), Hyalina (= Euconulus; Euconulidae), M:- crocystis (Euconulidae), and Parmacella (Parmacellidae) have been reported from amber of the Baltic region (KLEBS, 1886; SANDBERGER, 1887; LARSSON, 1978; family names updated). Photographs of unidentified snails in amber from the Dominican Republic have been presented in popular books (SCHLEE, 1980, 1986). Those and the forms de- scribed here are at least late Oligocene (25 Ma) in age and may be as old as late Eocene (40 Ma); they represent the earliest records of fossil land snails in Mesoamerica. The specimens described in this paper were obtained by the senior author from private collections and commercial sources. They are well preserved, many with soft tissues present. All probably represent snails that were living at the time they became covered with resin. Several show gas bubbles, which may represent gaseous products of decom- position or perhaps the expulsion of mucous froth by the entrapped animals. Only their preservation in the middle of blocks of fossil resin precludes description of the species in full detail. The specimens document the presence of seven land snail families in this chronostratigraphic setting. Four of the specimens can be assigned to specific extant genera. In the case of Strobilops, the occurrence alters his- torical biogeographic hypotheses that have been proposed for its group. All provide useful “tie points” for the ranges of their groups during the early to medial Tertiary period. MATERIALS anp METHODS The fossils in amber described here are from mines located in the Cordillera Septentrional of the Dominican Republic. The source is the Altamira facies of the El Mamey For- mation, shale and sandstone interspersed with conglom- erate of well-rounded pebbles, which has been assigned to the upper Eocene (EBERLE et al., 1980). Additional studies indicate that the amber in these mines ranges from late Eocene (40 Ma) to late Oligocene (25 Ma) in age (LaM- BERT et al., 1985; BERGGREN et al., 1985). The seven fossils discussed here are in seven separate, worked pieces of amber designated as C-1, MO-1-1, MO- 1-2, MO-1-3, MO-1-4, MO-1-5, and MO-1-6. Piece C-1 is roughly elliptical in shape, 2.7 cm X 1.6 cm X 0.7 cm, and weighs 1.9 g. Piece MO-1-1 is roughly elliptical, 3.7 cm X 1.8 cm x 1.1 cm, and weighs 4.3 g. Piece MO-1-2 is roughly hemispherical, 2 cm x 1.6 cm x 0.8 cm, and weighs 1.8 g. Piece MO-1-3 is elliptical, 3 em x 1.3 cm x 1 cm, and weighs 2.6 g. Piece MO-1-4 is 2.3 cm X 1.6 cm X 1.0 cm, and weighs 2.1 g. Piece MO-1-5 is 1.0 cm x 1.4 cm x 0.5 cm, and weighs 0.6 g. Piece MO-1-6 is 2.4 cm X 2.3 cm X 0.8 cm, and weighs 2.9 g. All pieces were tested for authenticity using methods described earlier (PoinaR, 1982). Specimens MO-1-1, MO-1-2, MO-1-3, MO-1-4, and MO-1-5 are in the Poinar collection of Do- minican amber at the University of California, Berkeley. Page 254 Specimen C-1 is in the Costa collection in the Museum of Dominican amber in Puerto Plata, Dominican Republic. Specimen MO-1-6 is in the Brodzinsky collection of Do- minican amber in Santo Domingo, Dominican Republic. SYSTEMATIC PALEONTOLOGY Class Gastropoda Subclass Pulmonata Family STROBILOPSIDAE Genus Strobilops Pilsbry, 1893 (?)Subgenus Coelostrobilops Pilsbry, 1927 Strobilops (?Coelostrobilops) sp. (Figures 1, 2) Specimen (MO-1-6) 1.8 mm in diameter, thin-shelled, depressed, with 4.25 whorls. Spire broadly conic; suture impressed. Periphery angulate; base convex. Embryonic whorls approximately 1.5, apparently unsculptured. Post- embryonic sculpture of fine, regularly spaced, threadlike, collabral ribs extending from suture to periphery, where they end abruptly. Aperture subcircular, oblique. Lip turned outward at about a right angle; inner lip scarcely impinging on umbilicus. Parietal callus thick, bearing two squarish lamellae; upper lamella much the larger. Palatal lip possibly with a basal plica. Umbilicus contained about 3.7 times in diameter. Remarks—Soft tissues are contained in the shell, visible behind the apertural barriers. The family Strobilopsidae has an extensive Recent and fossil distribution, reviewed by MANGANELLI et al., (1989). The two parietal lamellae visible from the outside in ap- ertural view, and the umbilicus more than one-fourth of the shell diameter, suggest assignment to the subgenus Coelostrobilops (type species: Strobilops wenziana Pilsbry, 1930). Coelostrobilops includes only two other known spe- cies, both Recent: Strobilops salvini (Tristram, 1863) from northern Guatemala, and S. wenziana from Grand Cay- man Island. Two lamellae are also visible in the apertures of species of Eostrobilops Pilsbry, 1927, but in those species the shell is sculptured with irregular incremental rugae rather than distinct ribs. This specimen represents the earliest unquestioned oc- currence of Strobilopsidae in the Western Hemisphere. The late Cretaceous or early Paleocene Strobilops mauryae Ferreira & Dos Santos Coelho, 1971, from Brazil is based on incomplete shells, and its assignment to Strobilopsidae is questionable (MANGANELLI et al., 1989). Two records of Strobilops from the Paleogene of the western interior of the United States (Hanley in TAYLor, 1975; repeated by ROTH, 1986) prove to be erroneous. The specimens on which those records are based, from U.S. Geological Sur- vey localities 20880 and 20881, an unnamed conglomeratic sequence of early Tertiary age along Little Granite Creek, The Veliger, Vol. 34, No. 3 Hoback Basin, northwestern Wyoming, consist of seven specimens, probably representing three taxa. None shows the diagnostic internal lamellae of Strobilops. The two spec- imens from USGS 20881 are 2.28 mm and 2.77 mm in diameter, with sinuous transverse major ribs approxi- mately 0.19 mm apart on the body whorl with 3-5 minor ribs in the interspaces. Compound ribbing of this type is not known in the Strobilopsidae. One specimen from USGS 20880 is a flattened, discoidal shell 3.15 mm in diameter, with sinuous, widely separated, threadlike transverse ribs approximately 0.16 mm apart, and parallel spiral striation that is absent from the last half whorl and may actually be a subsurface feature partly exposed by erosion. The four other specimens from USGS 20880 are depressed- helicoid shells with closely spaced ribs about 0.02 mm wide and interspaces of equal width. The ribbing is as strong on the base as on the spire. One shows faint spiral striation in the interspaces. Another has a 0.3-mm-long spiral la- mella inside the shoulder of the body whorl, about 0.1 mm back from the aperture, but no evidence of basal or parietal lamellae. The barrier is more suggestive of the lamellae in certain Helicodiscidae, or perhaps Megomphicidae. The next earliest records of Strobilops in the Americas are of Blancan (Pliocene, <5 Ma) age from Florida and Kansas (TAYLOR, 1966). The presence of a species of Strobilops in the Paleogene of Mesoamerica requires modification of the historical bio- geographic hypothesis advanced for the Strobilopsidae by MANGANELLI ef al., (1989). Rejecting PILsBRyY’s (1948) earlier concept of an Asian origin for the family, those authors suggested that the Strobilopsidae originated in the late Cretaceous or early Tertiary in an area of Laurasia corresponding to present-day Europe, before the opening of the North Atlantic Ocean had isolated North America from Europe. They attributed the presence of Strobilop- sidae in Central America to later dispersal (presumably, from North America). Similarly, SOLEM (1979a, b, 1981) regarded the Strobilopsidae as a group that had “moved” from its region of origin to a present limit of distribution several thousand kilometers distant. However, based on the present specimen, the earliest occurrence of the family in the Western Hemisphere is Mesoamerican. The earliest generally accepted Strobilop- sidae, from the Lutetian and Bartonian (middle Eocene, >40 Ma) of western Europe are all assigned to the extinct genus or subgenus Paleostrobilops Wenz, 1923 (type spe- cies: Helix menardi Brongniart, 1810); they have more complex internal barrier systems than any extant genera or subgenera. The earliest fossil strobilopsids assignable to extant genera are post-Bartonian: Strobilops (Strobilops) haedonensis (Edwards, 1852) and S. (S.) pseudolabyrinthica (Sandberger, 1873) from the Tongrian, late Eocene to early Oligocene, 38-35 Ma (BERGGREN et al., 1985). Depending on the age of the present specimen, then, strobilopsid land snails assignable to modern taxa may have been present in the American tropics at least as early as in western Europe. They probably formed part of an G. O. Poinar, Jr. & B. Roth, 1991 Page 255 Explanation of Figures 1-9 Figures 1, 2. Strobilops (?Coelostrobilops) sp. (MO-1-6). Top and basal views. Diameter 1.8 mm. Figures 3, 4. Subulina sp. (MO-1-2). Lateral and apical views. Height 11.5 mm. Figure 5. Spiraxis sp. (MO-1-3). Lateral view. Height 3.1 mm. Figure 6. Varicella sp. (MO-1-1). Lateral view. Height 10 mm. Figure 7. Prosobranch land snail, indeterminate (MO-1-5). Oblique lateral view showing soft tissues and associated gas bubbles. Height of shell 3.5 mm. Figure 8. Helicinid, genus and species indeterminate (C-1). Oblique apertural view. Diameter 3.0 mm. Operculum at arrow. Figure 9. ?Ferussaciid, genus and species indeterminate (MO-1-4). Lateral view. Height 7.6 mm. Page 256 early Tertiary land mollusk fauna that was arrayed across the southern part of North America, roughly parallel to the western limb of the Tethyan seaway (ROTH, 1986, 1988). Rather than having “moved” (as per SOLEM, 1979a), they may have undergone mainly a southward restriction of their northern range limit, perhaps accompanying cool- ing climates through the Tertiary period. This model further suggests that the cold-tolerance and northern distribution of such forms as Strobilops labyrin- thica (Say, 1817) and S. affinis Pilsbry, 1893, of the eastern United States is a secondarily derived attribute. This sug- gestion could be falsified by the finding of strobilopsids of this clade in rocks of late Eocene or older age in eastern North America (where, unfortunately, terrestrial deposits of the requisite age are rare). A phylogenetic hypothesis for the members of the Strobilopsidae will have to be devised before the temporal relationships between tropical and extratropical, American and European groups can be further resolved. Family SUBULINIDAE Genus Subulina Beck, 1837 Subulina sp. (Figures 3, 4) Specimen (MO-1-2) 11.5 mm long, 2.3 mm in greatest diameter; opaque, whitish. Lanceolate, slender, straight- sided, with 8+ evenly rounded, rather convex whorls, ta- pering to a blunt apex. Suture appressed, crenulated by a series of short, fine, subsutural folds. Aperture about 25% of total height. Prominent collabral lines, representing growth rests, present on penult and body whorl. Remarks—The specimen is remarkably similar to the Recent species Subulina octona (Bruguiére, 1792). It differs in the body whorl being slightly higher in proportion to total shell height. The buttonlike nuclear tip, nearly im- mersed in a globose first embryonic whorl, and the fine short folds that crenulate the suture are characteristic of the genus. Soft tissue around the aperture obscures details of the columella. The present range of Subulina includes the American tropics. There appears to be no prior record of the genus as fossils. Recent species of Subulina live in ground litter in moist places. Family SPIRAXIDAE Genus Spiraxis C. B. Adams, 1850 Spiraxis sp. (Figure 5) Specimen (MO-1-3) 3.1 mm long, 1.6 mm in greatest diameter, apparently rather solid, with 4.5 whorls (only spire present, base truncated by edge of matrix). Steeply conic, with deeply impressed to channeled suture; whorls narrowly shouldered. Embryonic whorls approximately 1.5, globose, apparently unsculptured. Postembryonic The Veliger, Vol. 34, No. 3 sculpture of narrow, rather crowded, axial ribs, weak at first but after 0.5 whorl becoming continuous across whorls, crenulating suture. Remarks—Apertural characters are not preserved. In its smooth protoconch, deeply impressed suture, and rather straight-sided whorls, this specimen resembles some Re- cent species such as Spiraxis subrectaxis Pilsbry, 1930, from Grand Cayman Island. It is, however, more broadly conic than is typical for modern species. The present range of Spiraxis includes Cuba, Jamaica, and other islands of the West Indies. There is no prior record of fossils of the genus (ZILCH, 1959-1960). Recent species of Spiraxis are typically found among plant debris on the ground (e.g., PILSBRY, 1930). (?) Family FERUSSACIIDAE ?Ferussaciid, genus and species indeterminate (Figure 9) Specimen (MO-1-4) 7.6 mm in height, 2.2 mm in greatest diameter, opaque, cream-white, solid, with about 5 whorls. Elongate, ovate-cylindrical, with strongly impressed suture and narrowly, almost tabulately shouldered whorls. Em- bryonic whorls apparently 2, carinate at shoulder, with close-set, sharp, axial ribbing. Postembryonic whorls smooth, with regularly spaced, incised, axial striations. Aperture about 60% of total height, narrow, pear-shaped, acute posteriorly, rounded anteriorly; outer lip apparently somewhat thickened within; basal lip produced; parietal wall with smooth callus; columella deeply arched, not trun- cated. Remarks—This specimen is referred questionably to Ferussaciidae on the basis of size and overall shape, relative height of body whorl, and shape of aperture and columella. However, the axially sculptured, shouldered embryonic whorls and the incised sculpture of the teleoconch are unlike anything heretofore reported in that family. The compressed ribbing resembles that of some modern species of Varicella Pfeiffer, 1856 (Oleacinidae). A keeled, ribbed protoconch occurs in some groups of Bulimulidae (e.g., subgenus Plicolumna Cooper, 1895, of Rabdotus Albers, 1850), but the present shell is not otherwise bulimuloid. The specimen may belong to an undescribed, extinct group, perhaps in Achatinoidea or Oleacinoidea. The Ferussaciidae are a pantropical group with a few genera in Mesoamerica (ZILCH, 1959-1960). Eocene through Miocene fossils are known from Europe. Recent species are ground-dwelling; some are fossorial. Family OLEACINIDAE Genus Varicella Pfeiffer, 1856 Varicella sp. (Figure 6) Specimen (MO-1-1) 10 mm in height, 3.1 mm in greatest diameter, translucent but solid, fusiform, without about 7 G. O. Poinar, Jr. & B. Roth, 1991 whorls. Spire narrowly conic, convex-sided; suture deeply impressed, crenulated by ribs; whorls narrowly shoul- dered. Embryonic whorls about 2, projecting, smooth, glo- bose. Postembryonic sculpture of strong, smooth, regularly spaced, shallowly sinuous, collabral ribs. Body whorl about 35% of height of shell, compressed, produced anteriorly; ribs becoming weaker on body whorl. Aperture narrow, pear-shaped; outer lip convex in profile, thickened outside and within; basal lip smoothly rounded; columella arched. Remarks—The Recent range of Varicella includes Ja- maica, central and eastern Cuba, Hispaniola, and Puerto Rico. There is no prior record of fossils of the genus (ZILCH, 1959-1960). Most Recent species of Varicella are ground- dwelling (BAKER, 1941, 1962), but the Jamaican Varicella (Costavarix) adamsiana is reported to be a “fair climber, at least occasionally” (BAKER, 1935). Subclass Prosobranchia Family HELICINIDAE Helicinid, genus and species indeterminate (Figure 8) Specimen (C-1) 2.5 mm in height, 3.0 mm in diameter, thin-shelled, translucent, light brown, trochoid, with slightly more than 4 whorls. Spire broadly conic; suture weakly impressed; whorls flattened. Nuclear tip prominent, tumid. Periphery subangulate, grading to rounded on last whorl; base flattened. Surface practically unsculptured, except for faint incremental lines; stronger collabral lines, repre- senting growth rests, present 0.5 and 0.7 whorls back from edge of lip. Aperture gibbous; lip unthickened above; basal lip slightly calloused, left edge produced, with shallow sinus at junction with columellar lip. Base imperforate, apparently with small callus pad in umbilical region. Remarks—Soft tissue extends outside the aperture, and a solid, discoidal structure, here interpreted as an oper- culum, lies near the base of the body whorl, in front of the aperture (Figure 8, arrow). If the living animal were partly extended, one would expect to find the operculum in a similar position. With its relatively unthickened lip, the specimen is probably immature. It cannot be assigned to a specific genus, but the available characters are consistent with several genera of the subfamily Helicininae, such as Helicina Lamarck, 1799, and Olygyra Say, 1818. The present range of the subfamily Helicininae includes the American and east Asian tropics and Pacific Islands. Considerable diversity occurs in Central America and the Greater Antilles. Helicinidae have an extensive and com- plex fossil record in North America, extending back to late Cretaceous time (ROTH, 1986; ROTH & PEARCE, 1988; PIERCE & RASMUSSEN, 1989). The generic allocation of many of the described fossils is uncertain (as PIERCE & RASMUSSEN, 1989, noted) and much further study is nec- essary before a phylogenetic hypothesis and biogeographic history can be postulated. Some Recent species are known to ascend trees (PILSBRY, 1948; Roth, personal observations). Page 257 Family Indeterminate Prosobranch land snail, genus and species indeterminate (Figure 7) Specimen (MO-1-5) approximately 3.4 mm in height, 2.8 mm in diameter, thin-shelled, brown, conical, with about 4 whorls. Apex blunt (sculpture eroded); suture moder- ately impressed; whorls narrowly shouldered. Postembry- onic sculpture of narrow, close-set, axial ribs, apparently slightly beaded. Base inflated, possibly umbilicate. Lip apparently simple; shape of aperture obscured by soft tis- sue. Remarks—The specimen is cracked from compression. Soft tissue, distorted by a gas bubble within, extends from the aperture. A flat structure that we interpret as an oper- culum is present a short distance outside the aperture. The presence of an operculum indicates that the spec- imen is a prosobranch. The conical shape and beaded axial sculpture suggest an immature member of the family An- nulariidae, but the absence of details of the adult aperture or of the operculum make it impossible to rule out high- spired Poteriidae such as Megalomastoma Swainson, 1840, or other taxa (cf. WENZ, 1938-1944). Both the Poteriidae and Annulariidae are at present restricted to the American tropics and are diverse in the Greater Antilles. Neither has a fossil record. DISCUSSION The land snail taxa indicate a tropical or paratropical climate. All the identified genera include Hispaniola or other Antillean islands in their Recent ranges. The oc- currence of a frog of the tropical American genus Lepto- dactylus in amber from the El] Mamey Formation (POINAR & CANNATELLA, 1987) is consistent with this climatic in- terpretation. Of the snails described here, the Varicella and helicinid species might plausibly be considered arboreal snails. Spe- cies of Subulinidae are mainly predaceous, ground-dwell- ing forms, and not normally found in trees. Strobilopsidae and Spiraxidae are predominantly found among plant lit- ter on the ground. According to LARSSON (1978), the snails reported from Baltic amber are also forest-floor dwellers found among rotting plant remains or in moss at the bases of trees. Most likely, these snails crawled in under the loose bark of logs or stumps seeking shelter, and there became entangled in resin. The association of snails and resin is noteworthy in itself. Modern forests dominated by highly resinous (e.g., conif- erous) trees tend to have low land snail diversity (SOLEM, 1984). ACKNOWLEDGMENTS We thank Bob O’Donnell and Emmett Evanoff for access to the collections of the U.S. Geological Survey in Denver, Page 258 Colorado. Michael P. Russell alerted BR to some pertinent literature. LITERATURE CITED Baker, H. B. 1935. Jamaican land snails, 5. The Nautilus 49(1):21-27, pl. 2. BaKER, H. B. 1941. Puerto Rican Oleacinidae. The Nautilus 55(1):24-30, pls. 1, 2. BAKER, H. B. 1962. Puerto Rican oleacinoids. The Nautilus 75(4):142-145. BERGGREN, W. A., D. V. KENT, J. J. FLYNN & J. A. VAN COUVERING. 1985. Cenozoic geochronology. Geological Society of America Bulletin 96(11):1407-1418. EBERLE, W., W. HIRDES, R. MUFF & M. PELAEZ. 1980. The geology of the Cordillera Septentrional. Proceedings of the 9th Caribbean Geological Conference, August 1980. Santo Domingo, D.R. Pp. 619-632. KLEBs, R. 1886. Gastropoden im Bernstein. Jahrbuch der Preussische Geologischen Landesanstalt fir 1885:366-394. LAMBERT, J. B., J. S. FRYE & G. O. POINAR, JR. 1985. Amber from the Dominican Republic: analysis by nuclear magnetic resonance spectroscopy. Archaeometry 27:43-51. Larsson, S. G. 1978. Baltic amber—a palaeobiological study. Entomonograph 1. Scandinavian Science Press: Klampen- bourg, Denmark. MANGANELLI, G., L. DELLE CAVE & F. GrusTI. 1989. Notulae Malacologiae, XLII. Strobilopsidae (Gastropoda, Pulmona- ta), a family new to the Villafranchian land snail fauna of Apenninic Italy. Basteria 53(1):3-13. PiERcE, H. G. & D. L. RASMUSSEN. 1989. New land snails (Archaeogastropoda, Helicinidae) from the Miocene (early Barstovian) Flint Creek Beds of western Montana. Journal of Paleontology 63(6):846-851. Pitssry, H. A. 1930. Results of the Pinchot South Sea Ex- pedition. I. Land mollusks of the Caribbean Islands, Grand Cayman, Swan, Old Providence and St. Andrew. Proceed- ings of the Academy of Natural Sciences of Philadelphia 82: 221-261, pls. 15-19. Piussry, H. A. 1948. Land Mollusca of North America (north of Mexico). Academy of Natural Sciences of Philadelphia, Monograph 3, 2(2):9-xlvii, 521-1113. Pornar, G. O., JR. 1982. Amber—true or false. Gems and Minerals 534:80-84. PornaR, G. O., JR. & D. C. CANNATELLA. 1987. An upper Eocene frog from the Dominican Republic and its impli- cation for Caribbean biogeography. Science 237:1215-1216. 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Early Tertiary mollusks from the Pow- der River Basin, Wyoming-Montana, and adjacent regions. U.S. Geological Survey Open-file Report 75-331:1-515, pls. 1-4. WENZ, W. 1938-1944. Gastropoda, Teil 1, Allgemeiner Teil und Prosobranchia. Handbuch der Paldozoologie 6(1):1- 1505 (1938); 1506-1639 (1944). ZILCH, A. 1959-1960. Gastropoda, Teil 2, Euthyneura. Hand- buch der Paldozoologie 6(2):1-400 (1959); 401-834 (1960). The Veliger 34(3):259-263 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Late Quaternary Chaenaxis tuba (Pupillidae) from the Sonoran Desert, South-Central Arizona by JIM I. MEAD Department of Geology and Quaternary Studies Program, Northern Arizona University, Box 6030, Flagstaff, Arizona 86011, and San Bernardino County Museum, Redlands, California 92374, USA AND THOMAS R. VAN DEVENDER Arizona-Sonora Desert Museum, 2021 N. Kinney Road, Tucson, Arizona 85743, USA Abstract. Shells of Chaenaxis tuba Pilsbry & Ferriss, 1906 (Pupillidae) were recovered from five radiocarbon-dated packrat (Neotoma) middens from the Waterman Mountains, northeastern Sonoran Desert, Pima County, Arizona. Associated plant macrofossils indicate that C. tuba has been present in rocky limestone habitats for 11,470 yr as the local vegetation shifted from a pinyon-juniper woodland in the late Wisconsin glacial to a postglacial juniper woodland/chaparral in the early Holocene (9920 yr B.P.) to a mesic Sonoran desertscrub in the middle Holocene (8910 to 4845 yr B.P.) to a modern desertscrub in the late Holocene (1320 yr B.P.). Chaenaxis tuba persisted in the community in spite of the climatic and vegetational changes within the local habitat. INTRODUCTION Fossil packrat (Neotoma spp.) middens have proven to be a rich source of fossils from the deserts of the southwestern United States and northern Mexico (see references in BE- TANCOURT et al., 1990). In the Sonoran Desert of Arizona, detailed reconstructions of vegetation and climate for the last 40,000 yr have been developed using abundant plant macrofossils from middens. Mesic ice-age pinyon-juniper- oak woodlands were replaced by more xeric juniper wood- land/chapparal in the early Holocene (11,000-9000 yr B.P. = radiocarbon years before 1950 a.D.). Although So- noran desertscrub developed after 9000 yr B.P., relatively modern communities were not present until about 4000 yrs ago (VAN DEVENDER, 1990). Various small vertebrates have been identified from Sonoran Desert middens from Arizona and California (VAN DEVENDER & MEAD, 1978; MEAD et al., 1983; VAN DEVENDER et al., in press a, b). Midden arthropods have been identified from five areas in southwestern Arizona and northwestern Sonora (HALL et al., 1988, 1989, 1990). In this paper, we report land snail shells from packrat middens from the Waterman Mountains of Arizona. MATERIALS anp METHODS Packrat middens are hard, dark organic deposits produced by various species of Neotoma (Rodentia, Cricetidae). In open areas, packrats build protective houses out of various plants, rocks, and animal remains collected within a forage distance of 30-50 m (FINLEY, 1958). Portions of dens constructed in dry rockshelters and crevices can be ce- mented with urine and preserved for tens of millennia (VAN DEVENDER e al., 1987). Chronological series of ra- diocarbon-dated assemblages (MEAD et al., 1978; VAN DE- VENDER et al., 1985; WEBB & BETANCOURT, 1990) can be used to reconstruct the local vegetation and fauna of rocky slopes through time. Snail shells were recovered from six packrat middens from the Waterman Mountains (WAM), Pima County, Page 260 115° The Veliger, Vol. 34, No. 3 10° ARIZONA Figure 1 Distribution of Chaenaxis tuba in Arizona and Sonora, Mexico. Stippled region represents the outline of the Sonoran Desert (TURNER & BROwN, 1982). Hachured area represents the overall range of C. tuba; large dots indicate the primary localities from BEQUAERT & MILLER (1973) and the Waterman Mountains. Solid triangle is the midden location northwest of Tucson. Line drawings of Chaenaxis after PILSBURY & FERRISS (1906). Arizona (32°20'30"N, 111°27'W). The samples were dis- aggregated in water, screened through a 20-mesh soil sieve, and sorted by hand. Radiocarbon dates on Neotoma sp. fecal pellets and Stzpa speciosa (desert needlegrass) florets ranged in age from the latest Wisconsin glacial (11,470 yr B.P.) to the postglacial late Holocene (1320 yr B.p.; Table 1). Although Chaenaxis tuba shells were not directly ra- diocarbon dated, the plant assemblages do not appear to be drastically mixed, an indication of only slight temporal contamination. Pollen and plant macrofossils from the middens were studied by ANDERSON & VAN DEVENDER (1991). The Waterman Mountains are in the Arizona Upland subdivision in the northeastern Sonoran Desert (SHREVE, 1964; TURNER & BROWN, 1982). The local vegetation is a rich, structurally diverse desertscrub dominated by Cer- cidium microphyllum (foothills paloverde), Encelia farinosa (brittlebrush), Olneya tesota (ironwood), Fouquieria splen- dens (ocotillo), Carnegiea gigantea (saguaro), and Partheni- um incanum (mariola). The midden crevices are in both the shady north-facing (WAM 1) and exposed south-fac- ing (WAM 9 and 10) cliffs at 790 m elevation on a steep east-west oriented limestone ridge. Modern litter samples from the cliff bases were screened and sorted for mollusk shells. Chaenaxis tuba was the only species recovered in litter from both slopes. Fossil and modern snails were identified through comparison with modern specimens at the Northern Arizona University, Laboratory of Quaternary Paleontology collection. Spec- imens were deposited into this collection. RESULTS anpb DISCUSSION All of the midden shells are the monotypic Chaenaxis tuba, a tiny snail of the family Pupillidae described by PILSBRY & FERRISS (1906) as a subgenus of Bifidaria from drift along the San Pedro River, opposite the Dragoon Moun- tains in Cochise County, Arizona. The shell of C. tuba has a hollow, broadly open umbilicus, which is diagnostic for the genus and nearly unique in the Pupillidae (BEQUAERT J. 1. Mead & T. R. Van Devender, 1991 Page 261 Table 1 Radiocarbon ages (years before 1950 = yr B.P.) for packrat middens containing Chaenaxis tuba shells from the Waterman Mountains, Pima County, Arizona. Dominant plants in the midden assemblages in order of decreasing relative abundances: = abundant, 4 = very common, 3 = common, 2 = uncommon. Radiocarbon age Sample Lab no.* (yr B.P.) Material dated 9A2 A-4777 11,470 +170 Neotoma sp. dung 9B A-4776 9920 + 130 Neotoma sp. dung 9C A-4779 8910 +110 Neotoma sp. dung 10 AA-3353 83600 +135 Stipa speciosa florets A-4780 8260 + 130 Neotoma sp. dung AA-3353, 8310 + 95 A-4780° 9D A-4781 5540 + 70 Neotoma sp. dung AA-3354 4845 + 80 Stipa speciosa florets A-4781, SL9O=EIS5 AA-3354° 1E A-4558 1320 + 45 Neotoma sp. dung Paleovegetation Dominant plants Pinyon-juniper woodland Acacia greggu (5) Juniperus sp. (5) Brickellia coulteri (3) Lycium sp. (3) Vauquelinia californica (3) Pinus monophylla (2) Juniperus sp. (5) Acacia greggi (4) Brickellia coulteri (3) Rhus cf. aromatica (3) Berberis sp. (2) Acacia greggu (5) Encelia farinosa (5) Lycium sp. (4) Rhus cf. aromatica (4) Crossosoma bigelovii (3) Sphaeralcea sp. (3) Acacia greggu (5) Ferocactus cylindraceus (5) Encelia farinosa (4) Lycium sp. (3) Rhus cf. aromatica (3) Carnegiea gigantea (5) Cercidium floridum (4) Encelia farinosa (4) Acacia greggu (3) Bursera cf. microphylla (3) Ferocactus cylindraceus (3) Hyptis emoryi (3) Opuntia versicolor (3) Prosopis velutina (3) Lycium cf. berlandiert (5) Carnegiea gigantea (4) Cercidium microphyllum (4) Opuntia phaeacantha (4) Ferocactus cylindraceus (3) Jatropha cardiophylla (3) Olneya tesota (3) Juniper woodland/chaparral Mesic Sonoran desertscrub Mesic Sonoran desertscrub Mesic Sonoran desertscrub Modern desertscrub * Radiocarbon codes: A, conventional radiocarbon method; AA, accelerator mass spectrometer method. » Dates averaged by the method of LONG & RIPPETEAU (1974). & MILLER, 1973; Figure 1 herein). The cylindrical or slightly tapering shell varies greatly in size and shape within a population. BEQUAERT & MILLER (1973) placed this species in the subfamily Pupillinae on the basis of its internal anatomy rather than in the Gastrocoptinae as implied by PiLsBry (1948). They hypothesized that Chae- naxis evolved in Arizona within the Southwestern Mollus- can Province. The Waterman Mountains midden speci- mens are the first fossil records for the genus. Today, Chaenaxis tuba is known from 460 to 1470 m elevation from southern Arizona and eastern Sonora. In the Sonoran Desert in Arizona, it has been found living under rocks and leafy plants in arid foothills and desert mountain ranges in portions of the Lower Colorado River Valley and Arizona Upland subdivisions receiving 100- 300 mm/yr precipitation. Our modern Waterman Moun- tains collections are a new locality. In Sonora, Mexico, it has been collected at 275 m in the Plains of Sonora sub- division near Hermosillo (PILSBRY, 1953; BRANSON et al., 1964). In central and southeastern Arizona, C. tuba can be found in higher, wetter (> 400 mm/yr) habitats ranging from Interior Chaparral (PASE & BROwN, 1982) below the Mogollon Rim to a complex mixture of Chihuahuan and Sonoran desertscrub, desert-grassland, and Madrean Page 262 oak woodland in southeastern Arizona. In desert-grassland on limestone slopes at 1465 m in the Dos Cabezas Moun- tains, Cochise County, southeastern Arizona, we found C. tuba under Dasylirion wheelert (sotol) and Nolina micro- carpa (beargrass). Prominent shrubs and succulents in- cluded Acacia greggu (catclaw acacia), A. neovernicosa (Chihuahuan whitethorn), Cercocarpus montanus (moun- tain mahogany), Fouquieria splendens, Mortonia semper- virons (sandpaper bush), Prosopis glandulosa (honey mes- quite), Quercus turbinella (shrub live oak), Rhus aromatica (skunk bush), and Agave palmeri (century plant). Chaena- xis tuba has also been found in eastern Sonora along the elevational gradient from lowland subtropical Sinaloan thornscrub to montane temperate woodlands and forests in the Sierra Madre Occidental. Snail shells have rarely been found in packrat middens. Plant macrofossils associated with the shells of Chaenaxis tuba provide a history of the local vegetation in its rocky, limestone habitat for the Holocene. Six late Wisconsin glacial middens (22,450 to 11,470 yr B.P.) in the Waterman Mountains record a pinyon-juniper woodland dominated by Juniperus osteosperma (Utah juniper) and Pinus mono- phylla (singleleaf pinyon) in association with such chap- arral plants as Quercus turbinella, Rhus cf. aromatica, and Vauquelinia californica (Arizona rosewood). Chaenaxis tuba was not found in five older late Wisconsin midden samples (implying that older Chaenaxis shells were not being mixed into younger, <11,500 yr B.P.., midden assemblages). The appearance of Chaenaxis tuba in the area correlates well with the arrival of Prosopis velutina (velvet mesquite), a desert-grassland dominant directly dated on seeds at 11,740 + 110 yr B.p. (AA-3577). The local vegetation shifted to a juniper woodland/chaparral dominated by Juniperus cf. erythrocarpa (redberry juniper) in the early Holocene (9920 yr B.P.), to a mesic Sonoran desertscrub in the middle Holocene (8910 to 4845 yr B.P.) and to a relatively modern desertscrub in the late Holocene (1320 yr B.P.). The modern vegetation reflects a more xeric cli- mate than any of the midden assemblages. Our conclusions rest on the assumption that the Chaena- xis shells are contemporaneous with each of the midden assemblages. This assumption is justified for two reasons: (1) five of the oldest middens, from the same series, do not contain Chaenaxis shells, and (2) multiple radiocarbon dates from two middens do not indicate drastic temporal mixing. The late Wisconsin-to-modern vegetation development in the Waterman Mountains includes most of the vegetation types presently known for C. tuba. The continued presence of this tiny pupillid in the study area is testimony to its successful adaptation to a xeric, rocky habitat rather than to a particular vegetation type or climatic regime. ACKNOWLEDGMENTS We thank Chris Bell (Northern Arizona University) for laboratory assistance. Emilee Mead drafted the figure, and Maxine Campbell (Center for Colorado Plateau Studies) The Veliger, Vol. 34, No. 3 typed the manuscript. Laurence J. Toolin (National Sci- ence Foundation Facility for Radioisotope Analysis, Uni- versity of Arizona) provided two tandem accelerator mass spectrometer radiocarbon dates on florets of Stzpa speciosa. Albert R. Mead and Walter B. Miller have provided help- ful discussions regarding molluscan studies of the arid Southwest. Paul S. Martin (Desert Laboratory, University of Arizona) has provided stimulating discussions on the ecology and paleoecology of the deserts of the Southwest for more than two decades. Helpful suggestions for our manuscript were received from Dr. D. W. Phillips and two anonymous reviewers. Funds were provided by the Roy Chapman Andrews Fund of the Arizona-Sonora Des- ert Museum. LITERATURE CITED ANDERSON, R. S. & T. R. VAN DEVENDER. 1991. Palynology and packrat (Neotoma) middens: a chronological sequence from the Waterman Mountains, southern Arizona U.S.A. Review of Paleobotany and Palynology. BEQUAERT, J. C. & W. B. MILLER. 1973. The Mollusks of the Arid Southwest with an Arizona Check List. University of Arizona Press: Tucson, Arizona. 271 pp. BETANCOURT, J. L., T. R. VAN DEVENDER & P. S. MARTIN. 1990. Packrat Middens: The Last 40,000 Years of Biotic Change. University of Arizona Press: Tucson, Arizona. 467 PP- BRANSON, B. A., C. J. McCoy & M. E. Sisk. 1964. Notes on Sonoran gastropods. The Southwestern Naturalist 9:103- 104. FINLEY, R. B. 1958. The woodrats of Colorado: distribution and ecology. University of Kansas Publication in Natural History 10:213-552. HALL, W. E., T. R. VAN DEVENDER & C. A. OLSON. 1988. Late Quaternary arthropod remains from Sonoran Desert packrat middens, southwestern Arizona and northwestern Sonora. Quaternary Research 29:277-293. HALL, W. E., C. A. OLSON & T. R. VAN DEVENDER. 1989. Late Quaternary and modern arthropods from the Ajo Mountains of southwestern Arizona. Pan-Pacific Entomol- ogist 65:322-347. HALL, W. E., T. R. VAN DEVENDER & C. A. OLSON. 1990. Arthropod history of the Puerto Blanco Mountains, Organ Pipe Cactus National Monument, southwestern Arizona. Pp. 363-379. In: J. L. Betancourt, T. R. Van Devender & P. S. Martin (eds.), Packrat Middens: The Last 40,000 Years of Biotic Change. University of Arizona Press: Tucson, Arizona. 467 pp. Lone, A. & B. RIPPETEAU. 1974. Testing contemporaneity and averaging radiocarbon dates. American Antiquity 39:205- 2S: Meap, J. I., R. S. THompson & A. LONG. 1978. Arizona radiocarbon dates IX: carbon isotope dating of packrat mid- dens. Radiocarbon 20:171-191. MeapD, J. I., T. R. VAN DEVENDER & K. L. COLE. 1983. Late Quaternary small mammals from Sonoran Desert packrat middens, Arizona and California. Journal of Mammalogy 64:173-180. PasE, C. P. & D. E. BRown. 1982. Interior chaparral. Pp. 95- 99. In: D. E. Brown (ed.), Biotic Communities of the Amer- ican Southwest— United States and Mexico. Desert Plants 4:1-342. J. I. Mead & T. R. Van Devender, 1991 Piuspry, H. A. 1948. Land Mollusca of North America (north of Mexico). II. Part 2. The Academy of Natural Sciences of Philadelphia, Monograph 3. Piussry, H. A. 1953. Inland Mollusca of northern Mexico. II. Urocopitidae, Pupillidae, Strobilopsidae, Valloniidae and Cionellidae. Proceedings of the Academy of Natural Sciences of Philadelphia 105:133-167. Piussry, H. A. & J. H. Ferriss. 1906. Mollusca of the south- western States. II. Proceedings of the Academy of Natural Sciences of Philadelphia 58:123-175. SHREVE, F. 1964. Vegetation of the Sonoran Desert. Pp. 1- 186. In: F. Shreve & I. L. Wiggins, Vegetation of the Sonoran Desert. Stanford University Press: Stanford, California. 1740 Pp: TURNER, R. M. & D. E. BRown. 1982. Sonoran desertscrub. Pp. 181-221. In: D. E. Brown (ed.), Biotic Communities of the American Southwest— United States and Mexico. Desert Plants 4:1-342. VAN DEVENDER, T.R. 1990. Late Quaternary vegetation and climate of the Sonoran Desert, United States and Mexico. Pp. 134-163. In: J. L. Betancourt, T. R. Van Devender & P. S. Martin (eds.), Packrat Middens: The Last 40,000 Years of Biotic Change. University of Arizona Press: Tucson, Arizona. 467 pp. VAN DEVENDER, T. R. & J. 1. MEAD. 1978. Early Holocene and late Pleistocene amphibians and reptiles in Sonoran Desert packrat middens. Copeia 1978:464-475. Page 263 VAN DEVENDER, T. R., P. S. MARTIN, R. S. THompson, K. L. Cote, A. J. T. Jui, A. Lone, L. J. Toouin & D. J. DONAHUE. 1985. Fossil packrat middens and the tandem accelerator mass spectrometer. Nature 317:610-613. VAN DEVENDER, T. R., R. S. THOMPSON & J. L. BETANCOURT. 1987. Vegetation history in the Southwest: the nature and timing of the late Wisconsin-Holocene transition. Pp. 323- 352. In: W. F. Ruddiman & H. E. Wright, Jr. (eds.), North America and Adjacent Oceans During the Last Deglaciation. Decade of North American Geology K-23. Geological So- ciety of America: Boulder, Colorado. 501 pp. VAN DEVENDER, T.R., J. I. MEAD & A. M. REA. In press a. Late Quaternary plants and vertebrates from Picacho Peak, Arizona. The Southwestern Naturalist. VAN DEVENDER, T. R., A. M. REA & W. E. HALL. In press b. Faunal analysis of late Quaternary vertebrates from Or- gan Pipe Cactus National Monument, southwestern Ari- zona. The Southwestern Naturalist. Wess, R. H. & J. L. BETANCOURT. 1990. The spatial and temporal distribution of radiocarbon ages from packrat mid- dens. Pp. 85-102. Jn: J. L. Betancourt, T. R. Van Devender & P. S. Martin (eds.), Packrat Middens: The Last 40,000 Years of Biotic Change. University of Arizona Press: Tucson, Arizona. 467 pp. The Veliger 34(3):264-271 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Generic Identity and Relationships of the Northeastern Pacific Buccinid Gastropod Searlesia dira (Reeve, 1846) GEERAT J. VERMEIJ Department of Geology, University of California, Davis, California 95616, USA Abstract. The buccinid gastropod genus Searlesia Harmer, 1914, contains about a dozen nominal species from the Oligocene to the Pliocene of Europe, with type species 7rophon costifera S. V. Wood, 1848. Oligocene to Recent species assigned to Searlesia from the North Pacific differ consistently from the European species by having an internally lirate aperture and a simple, rather than thickened or reflected, adult lip. The Pacific species are here assigned to the new genus Lirabuccinum, with type species Buccinum dirum Reeve, 1846, from the northeastern Pacific. Suggestions that Lirabuccinum invaded the Atlantic during the Pliocene, when it gave rise to European species of Searlesia, are rejected in favor of the hypothesis that the two genera evolved separately in the Atlantic and Pacific oceans respectively and remained confined to the oceans in which they originated. The name Searlesia dentifera is here proposed to replace Searlesia ravni Schnetler in Schnetler & Beyer, 1990, non Harmer, 1914. INTRODUCTION The genus Searlesia Harmer, 1914, was erected to encom- pass Trophon costiferum Wood, 1848, and about a dozen other species from the Pliocene of the North Sea basin and Iceland (HARMER, 1914-1923). All twentieth-century au- thors have considered Searlesia to belong to the Buccinidae. In his initial treatment of the genus in 1914, Harmer alluded to a letter from W. H. Dall in which Dall ex- pressed the view that Buccinum dirum Reeve, 1846, a com- mon Recent northeastern Pacific species, should be in- cluded in Searlesca along with the European Pliocene fossils. DALL (1916, 1918) reaffirmed this assignment of B. dirum to Searlesia in his review of North Pacific buccinids, and in 1918 he added a second Recent species, S. constricta Dall, 1918, from Korea. All subsequent workers have ac- cepted the assignment of B. dirum to Searlesia. Several additional species from western North America and east- ern Asia were subsequently described, with the result that the stratigraphical range of the Pacific members of Searlesia came to be regarded as Oligocene to Recent. Dall probably had no specimens of Searlesia costifera with which to compare Buccinum dirum, and therefore seems to have relied wholly on the illustrations and de- scriptions supplied to him by Harmer. This may explain why Dall overlooked, or failed to appreciate, the differ- ences in shell form between the two species, which are superficially very similar. In order to assess the taxonomic position of the European and Pacific species assigned to Searlesia, I examined all type specimens of species referred to Searlesia and Cali- cantharus at the U.S. National Museum of Natural History (USNM), Washington, and at the Museum of Paleontol- ogy, University of California, Berkeley (UCB). In addi- tion, I examined species of Pirgos and related European buccinids at the National Museum voor Natuurlijke His- torie (NMNH), Leiden, and species of Searlesia and Cal- icantharus at the California Academy of Sciences (CAS), San Francisco. Assignments of Oligocene European species and of fossil Asian species were based on descriptions in the literature. Although the descriptions are adequate for generic assignments, I have not attempted a full-scale review of all described species. Not only were type spec- imens not available for many of them, but several taxa are based on so few specimens that it would have been im- possible to decide on the basis of the available material whether individuals belong to one or a few variable species or to many closely related but phenotypically rather ho- mogeneous species. In this paper, I shall try to show that the European and Pacific species now generally included in Searlesia belong to two lineages with long separate histories, one in Europe Gar Vermeij; 1991 (Searlesia), the other in the temperate North Pacific. I propose Lirabuccinum [type species: Buccinum dirum Reeve, 1846] as a new genus to encompass the latter group. The biogeographical implications of this new interpretation are briefly considered at the end of the paper. SYSTEMATICS Genus Searlesia Harmer, 1914 Type species: Trophon costuferum Wood, 1848. Description: Shell fusiform; protoconch eroded and there- fore unknown; teleoconch whorls somewhat tabulate; axial sculpture of narrowly rounded straight orthocline folds that on the spire whorls extend suture to suture and on the body whorl extend only part of the way toward the base; axial folds variable in number, prominence, and on- togenetic extent; spiral sculpture of numerous thin cords and secondary threads crossing the axial folds; adult outer lip slightly thickened or reflected, smooth within; inner lip weakly concave, smooth; siphonal canal straight, not de- flected to the left, not curved upward at end, not distinctly set off from rest of shell; no posterior notch; operculum and animal unknown. Composition and comparisons: HARMER (1914-1923) assigned 10 species to the genus Searlesia, all from the Pliocene of the North Sea basin and from the Pliocene of Iceland (see also GLADENKOV et al., 1980). These species, together with their places and times of occurrence, are listed in Table 1. I have not critically reviewed these spe- cies, but I am highly skeptical that they are all distinct. Harmer noted intermediates between some of them, and many were described on the basis of one or two specimens. Many Recent buccinids show great intrapopulational vari- ation in spire height and in the expression of axial sculp- ture, just the characteristics used by Harmer in distin- guishing among his species. JANSSEN (1979) added Searlesia mitgaui (von Koenen, 1867), from the late Oligocene (Chattian) of Germany, to the genus. This species has the outer lip smooth on its inner surface, and bears sculpture similar to that of S. costifera. It apparently continued into the early Miocene of Belgium, where it was represented by Euthria antwerpi- ensis Glibert, 1952, a probable synonym of S. mitgaui ac- cording to JANSSEN (1979). Two additional Oligocene species have subsequently been added by SCHNETLER & BEYER (1990). Searlesia ko- nincki (Nyst, 1845) from the Rupelian of Belgium and Germany and S. ravni Schnetler in Schnetler & Beyer, 1990, from the late Oligocene (Chattian) of Denmark, share with S. mztgaui the presence of a small parietal tooth. This feature is not seen in S. costifera. It may be that these three Oligocene species should be referred to a distinct genus or subgenus (see also SCHNETLER & BEYER, 1990). Unfortunately, Schnetler’s S. ravni is a primary homonym of S. ravni Harmer, 1914, a Pliocene species. In view of Page 265 Table 1 List of the nominal species of Searlesia. S. bjornsont Morch & Poulsen in Harmer, 1914: late Pliocene (Waltonian to Butleyan Red Crags of England, Serripes zone of Tjornes section, Iceland). S. costifera (Wood, 1848) (type): early Pliocene (Coralline Crag of England; Mactra zone of Tjérnes section, Iceland); late Plio- cene (Waltonian to Butleyan Red Crags of England; Isle of Man). S. elegans Harmer, 1914: late Pliocene (Waltonian Red Crag of England). S. forbest (Strickland, 1846): late Pliocene (Waltonian Red Crag of England; Isle of Man). S. harrisoni A. Bell in Harmer, 1914; late Pliocene (Isle of Man). S. konincki (Nyst, 1845): middle Oligocene (Rupelian, western Europe). S. lundgrent Morch & Poulsen in Harmer, 1914: early Pliocene (Mactra zone of Tjérnes section, Iceland); late Pliocene (Ser- ripes zone, Tjornes section, Iceland). S. mitgaui (von Koenen, 1867): late Oligocene (Chattian, Ger- many); early Miocene, Belgium. S. nordmanni Harmer, 1914: late Pliocene (Waltonian Red Crag of England; Isle of Man). S. oyent Harmer, 1914: late Pliocene (Isle of Man). S. proxima Harmer, 1914: late Pliocene (Waltonian Red Crag of England). S. ravni Harmer, 1914: early Pliocene (Coralline Crag of En- gland); late Pliocene (Waltonian Red Crag of England). S. dentifera Vermeij, 1991, new name: late Oligocene (Chattian, Denmark). the tooth on the parietal wall of the Oligocene species, I here propose the replacement name S. dentifera, new name, for the Danish species. The species Searlesia forbesi (Strickland, 1846) was said by HARMER (1914-1923) to differ from S. costifera and other species of Searlesia by the denticulation of the outer lip of the adult. It is unclear from his description and illustrations if this denticulation is in the form of small teeth, which would be discontinuous in the spiral direction, or if they represent spirally continuous lirae. For the time being I regard S. forbesi as a bona fide Searlesia. HARMER (1914-1923) doubtfully included Fusus alveo- latus Sowerby, 1829, and Trophon consocialis Wood, 1848, both ranging from the late Miocene to the late Pliocene of the North Sea basin, in his genus Searlesia. Previously, however, DE GREGORIO (1885) had erected the genus Pirgos [type species: F’. alveolatus] to encompass these species, and several authors have retained this assignment (VAN REG- TEREN ALTENA et al., 1957; GLIBERT, 1963). Harmer was evidently unaware of de Gregorio’s taxon Pirgos, for oth- erwise he might have chosen it to include S. costifera and related British forms. Species of Pirgos differ from S. cos- tufera by having more numerous axial ribs and sharper, more distantly spaced spiral ribs, which cross to form a beaded sculpture. Because of similarities in the ontogeny of spiral and axial sculpture, TEMBROCK (1968) regarded Pirgos as a Page 266 subjective junior synonym of Scalaspira Conrad, 1862 [type species: S. strumosa (Conrad, 1831, early Pliocene York- town Formation, Virginia]. She further suggested that the species previously placed in Pirgos belong to a lineage beginning with S. elegantula (Philippi, 1843) from the late Oligocene of Germany. The latter species, together with many other species from the Oligocene and Miocene of western Europe, had previously been assigned to Aquilo- fusus Kautsky, 1925 [type species: A. puggaardi (Beyrich, 1856)], which TEMBROCK (1968) also synonymized under Scalaspira. In her greatly expanded concept of Scalaspira, TEM- BROCK (1968) brought together gastropods ranging in age from Eocene to Recent in the Atlantic and from Oligocene to Recent in the North Pacific. In addition to Pirgos, Aquil- ofusus, and the Miocene and Pliocene western Atlantic species of Scalaspira, she included in Scalaspira the genera Mohnia Friele in Kobelt, 1878 [type species: M. mohni (Friele, 1877)] from the Recent North Atlantic and the Pliocene to Recent of the North Pacific; Troschelia Morch, 1877 [type species: 7. berniciensis (King, 1846)] from the late Pliocene to Recent of the northeastern Atlantic; and others. In addition, Tembrock included the Pliocene to early Pleistocene Japanese Searlesia japonica Yokoyama, 1926, and S. decessor Yokoyama, 1928, here regarded as belonging to the new genus Lirabuccinum (see below); An- cistrolepis clark: Tegland, 1933, from the Oligocene Blake- ley Formation of Washington, which is usually assigned to Ancistrolepis Dall, 1895 [type species: A. eucosmius (Dall, 1891)] or a related genus (see MoorRE, 1984; GLADENKOV et al., 1988); and some middle to late Miocene species related to Sipho gregarius Philippi, 1846, here tentatively assigned to Colus Roding, 1798 [type species: C. islandicus (Mohr, 1786)]. All these gastropods have a small first whorl followed by a variable number of whorls with a trellislike sculpture composed of spiral and axial elements (TEMBROCK, 1968). The axial sculpture typically appears a little later than do the spiral cords, and may be absent in some species. Adults of the various species differ greatly in size, sculpture, and length of the siphonal canal. Amer- ican species of Scalaspira have strong spiral cords that form nodes where they cross the narrow axial folds, and have a sharply recurved siphonal canal. Species of Mohnia have thin narrow spiral threads and, like members of the C. gregarius complex, lack axial sculpture. Pirgos shares with Aquilofusus the strong spiral cords that form small nodes where they cross the numerous axial ribs. I agree with TEMBROCK (1968) that Pirgos and Aquilofusus are very closely related. A review of all taxa considered by Tem- brock to belong to Scalaspira is beyond the scope of this paper, but I suspect that several genus-level groups are involved, of which Pirgos (including the subjective junior synonym Aquilofusus) is one. Because the protoconch and early teleoconch whorls of Searlesia remain unknown, the relationship of that group to the Scalaspira complex cannot be assessed. It is noteworthy, however, that all species of Searlesia (except perhaps S. forbesz) and all of Tembrock’s The Veliger, Vol. 34, No. 3 Scalaspira (except for two Japanese species here assigned to Lirabuccinum) have the outer lip smooth within. Another related genus is Euthria Gray 1850. The Recent Mediterranean species FE. cornea (Linnaeus, 1758), which is the type species of the genus, lacks apertural lirae, as do several Miocene and Pliocene species from southern Europe. The adult outer lip is thickened and reflected, as in Searlesia, but the spiral sculpture is typically very fine and the axial sculpture generally consists of narrow ribs that often become obsolete on later whorls. Buccinulum Deshayes, 1830, is often regarded as at most subgenerically distinct from Euthria (PONDER, 1971). Most of the Aus- tralian and New Zealand species of Buccinulum, including its type species B. lineum (Martyn, 1784), have a lirate aperture (see below). In summary, Searlesia is a European genus with a range of early Oligocene to late Pliocene, with a gap in the record in the middle and late Miocene. I regard Searlesia as dis- tinct from, but perhaps related to, Pirgos and perhaps other taxa in Tembrock’s broadly conceived version of Scalaspira. Genus Lirabuccinum Vermeij, gen. nov. Type species: Buccinum dirum Reeve, 1846. Diagnosis: Shell fusiform, spire approximately half the total shell height; spiral sculpture of fine threads, increas- ing in width toward base; threads override wide, rounded, low, often slightly oblique axial folds that extend suture to suture in the spire whorls; on body whorl, axials fade out toward base; axials often obsolete on part or all of body whorl; outer lip simple, neither thickened nor re- flected, lirate within, the number of lirae corresponding with the number of external spiral threads; siphonal pro- tuberance short, deflected slightly to left, slightly recurved dorsally, not distinctly set off from rest of shell; inner lip smooth, with single weak basal fold. Composition and comparisons: In shape and sculpture, Lirabuccinum (Figure 1C, D) closely resembles Searlesia (Figure 1A, B), such that it is easy to see why Dall and others have considered the European fossil species and the North Pacific species to belong to the same genus. Both have fusiform shells with broad axial folds and fine spiral threads. This combination of traits is, however, widespread in the Buccinidae and in related families, and is by itself hardly diagnostic. Lirabuccinum differs from Searlesia in at least four ways. The inner surface of the outer lip in Livabuccinum is lirate, whereas in Searlesia it is smooth. The outer lip in Lira- buccinum is thin and unreflected, whereas in adult Searlesia it is thickened or somewhat reflected. In Lirabuccinum, the siphonal canal is short and slightly twisted to the left, as well as dorsally deflected; in Searlesia, it is straight and not recurved. Finally, the axial folds of Lirabuccinum are broader and somewhat more oblique in orientation than are the orthocline, more sharply rounded axials of Searlesia. Another genus that is morphologically similar to Lira- Gaye Vermeij; 1991 Page 267 BE EOS Figure 1 A and B. Searlesia costifera (Wood, 1848), Ellewoudsdijk, Zeeland, Netherlands, beach drift (NMNH); apertural and dorsal views. C and D. Lirabuccinum dira (Reeve, 1846), Whiffen Spit, Sooke, Vancouver Island, British Columbia (Vermeij collection); apertural and dorsal views. Scale bar: 1 cm. Page 268 buccinum is Calicantharus Clark, 1938 [type species: C. fortis (Carpenter, 1866)], known from the Paleocene or Eocene to the Pleistocene of western North America. Spe- cies of Calicantharus differ from Lirabuccinum by the pres- ence of a concave area below the suture on the body whorl, an angulation or rounded swelling on the body whorl below this concave area, the smooth rather than lirate inner sur- face of the outer lip, and by the axial sculpture, which is expressed as axially elongated knobs or nodes rather than as continuous axial folds as in Lirabuccinum. ADDICOTT (1970) assigned Turris carlsoni Anderson & Martin, 1914, which was included in Searlesia by ADEGOKE (1969) and questionably in that genus by Moore (1963), to Calicantharus. This species, which occurs in the Miocene Astoria Formation of Oregon, has a concave subsutural area, a swelling below this concave area, and axial sculp- ture usually consisting of nodes that are most prominent on the swelling. The aperture of most specimens cannot be inspected because of the presence of matrix, but some broken specimens in the collections at UCB reveal a smooth interior. The assignment of 7. carlsoni to Calicantharus therefore seems reasonable. I disagree with ADDICOTT (1970) that Searlesia dira miocenica Etherington, 1931, from the Astoria Formation of Grays Harbor, Washington, is a dwarf or juvenile form of Calicantharus kernensis (Anderson & Martin, 1914). Etherington’s taxon closely resembles the living Lizrabuc- cinum dirum in sculpture. Although the apertures of both the holotype and paratype at UCB are filled with matrix, the holotype shows distinct crenulations on the outer lip, indicating the presence of internal lirae. The whorls are evenly convex, and the distinct subsutural concavity is lack- ing despite ETHERINGTON’S (1931) claim to the contrary. I therefore agree with ETHERINGTON (1931) that this taxon is very Close to the living L. dirum, and I place it in Lirabuc- cinum. Calicantharus kernensis from the Jewett Sand (early Miocene) of California is a typical Calicantharus with a smooth outer lip, subsutural concave area, and weakly developed nodes. WoopRING & BRAMLETTE (1950) considered Chryso- domus portolaensis Arnold, 1908, from the upper Etchegoin and lower Purisima Formations of the Pliocene of Cali- fornia, as a species of Calicantharus. Inspection of the ho- lotype at the USNM and of several lots at CAS, however, revealed that the axial sculpture (though absent on the body whorl) is expressed as continuous if bulging folds in the spire whorls, and that the inner surface of the outer lip is lirate. I therefore agree with GRANT & GALE (1931) in placing this species in their Searlesia (= Lirabuccinum herein). Several other fossil species from the northeastern Pacific have been allocated to Searlesia by previous authors. Sear- lesia dira Clark, 1918, from the San Ramon Sandstone (Oligocene) of California, and S. branneri Clark & Arnold, 1923, from the Sooke Formation (early Miocene) of British Columbia, have regularly convex whorls and continuous axial folds disposed somewhat obliquely on the body whorl. The Veliger, Vol. 34, No. 3 Although the aperture cannot be observed in the available specimens at UCB, assignment to Lirabuccinum is plau- sible. Moore (1963) suggested that Turris cammani Dall, 1909, and 7. coosensis Dall, 1909, both from the Empire Formation (late Miocene) of Oregon, belong to Searlesia. Turris cammani has a distinct posterior notch and lacks axial sculpture; it does not appear to be a buccinid. Tur7is coosensis lacks a posterior notch and possesses axial folds overridden by about 18 strong spiral threads separated by narrow grooves, but the holotype (the only available spec- imen at USNM) is missing the spire and the anterior canal, and its aperture is filled with matrix. This species may belong to Lirabuccinum, but I prefer to regard it as taxo- nomically indeterminable. Searlesia olympicensis Durham, 1944, from the Quimper Sandstone (Oligocene) of Wash- ington, has a very short spire and differs from all species of Lirabuccinum by lacking axial sculpture. The apertural features of the unique holotype at UCB cannot be observed, but the absence of axial sculpture and the very short spire place this fossil outside the limits of Lirabuccinum as here defined. In the western Pacific, seven taxa have been assigned by previous authors to Searlesia. Fusus modestus Gould, 1846, and its subspecies fuscolabiata (Smith, 1875) resem- ble small Livabuccinum dirum in form and in having un- usually strong axial folds. Searlesia constricta Dall, 1918 (Recent, Korea) and Fusus coreanicus Smith, 1875 (warm- temperate western Pacific) are superficially similar to L. modestum and may well belong to a single somewhat vari- able Recent species. Fossil taxa described as Searlesia from the western Pacific include S. japonica Yokoyama, 1926, and §. decessor Yokoyama, 1928, from the Pliocene of Japan, and S. kavranensis Sinelnikova in Gladenkov et al., 1984, from the Ilinsk Suite (middle Miocene) of Kam- chatka. All these species have a lirate outer lip and possess axial folds, and therefore appear to belong to Lirabuccinum. AMANO (1983) has, in addition, pointed to an unidentified species from the Togeshita Formation (early Miocene) of Hokkaido. Finally, Searlesia iljinensis Sinelnikova in Glad- enkov et al., 1984, from the Ilinsk Suite of Kamchatka, was excluded by GLADENKOV et al. (1988) from Searlesia (= Lirabuccinum of this paper) on account of its smooth outer lip. GLADENKOV et al. (1988) place S. ijznensis in Plicifusus Dall, 1902 [type species: P. kroeyer: (Moller, 1842)]. It is likely that many of these names are synonyms of one or a few somewhat variable species, because the pur- ported differences are not great. Searlesia kavranensis is said to have less regular spiral sculpture and a shorter spire than the approximately coeval Lirabuccinum branneri (see GLADENKOV et al., 1984). The expression of spiral sculpture, however, may depend on the shell’s state of preservation. YOKOYAMA (1926), for example, pointed out that the spiral ribs on slightly eroded specimens of L. japonicum have a tripartite appearance not seen in well- preserved shells. Lirabuccinum branneri was said by CLARK & ARNOLD (1923) to differ from L. dirum in that the axial G. J. Vermeij, 1991 Page 269 folds extend onto the body whorl, whereas in L. dirum and in L. portolaense they are confined mainly or entirely to the spire whorls. As in other axially sculptured buccinids and related groups, there is considerable intrapopulational variation in the expression of axial sculpture in L. dirum. Some large L. dirum have axial folds on the whole of the body whorl, whereas others lack folds on this part of the shell. In the northeastern Pacific, therefore, a case could be made that there is a single somewhat variable species of Lirabuccinum that appeared as early as the early Mio- cene. The number and limits of species of Lirabuccinum cannot be decided definitively without more extensive fossil material than is now available. A list of the nominal species of Lirabuccinum is given in Table 2. The 12 taxa range in age from Oligocene to Recent in the eastern Pacific, and from early Miocene to Recent in the western Pacific. RELATIONSHIPS anp BIOGEOGRAPHY Weare still far from an evolutionary understanding of the Buccinidae and related families. This is well reflected in uncertainties surrounding the scope and limits of the family (PONDER & WAREN, 1988) and in the difficulties of as- signing many deep-sea species to family units (BOUCHET & WaAREN, 1986). My purpose here is to review the tax- onomic distribution within the Buccinidae of some of the characters that distinguish Searlesia from Lirabuccinum, and to consider the biogeographical implications of these differences. Lirabuccinum is one of only two genera of cool-water northern Buccinidae with a lirate outer lip. The other genus is the northwestern Pacific Barbitonia Dall, 1916 [type species: B. arthritica (Bernardi, 1858)], ranging in age from Miocene to Recent. This taxon has traditionally been regarded as a subgenus of Neptunea Roding, 1798 [type species: N. antiqua (Linnaeus, 1758)] (see DALL, 1916, 1918; HaBE & SaTo, 1973; GORYACHEV, 1987). NELSON (1978), however, concluded on the basis of shell microstructure that Barbitonza is not closely allied to Nep- tunea, but instead belongs to the group that POWELL (1951) referred to as the Buccinulidae, and that others regard as at most a subfamilial unit Buccinulinae. The Buccinulinae includes many tropical species as well as the majority of cool-water Southern-Hemisphere buccinids. Among the genera included in this group are Buccinulum Deshayes, 1830 [type species: B. lineum (Martyn, 1784)] from the late Oligocene or early Miocene to the Recent of New Zealand and Australia (PONDER, 1971; BEU & MAXWELL, 1990); Siphonalia A. Adams, 1963 [type species: S. cassi- dariaeformis (Reeve, 1846)] from the Eocene to the Recent of east Asia (RUTH, 1942; GLADENKOV et al., 1988); Kel- letia Fischer, 1884 [type species: K. kelletii (Forbes, 1850)] from the Paleocene to the Recent of the eastern Pacific (RUTH, 1942); Penion Fischer, 1884 [type species: P. di- latatus Quoy & Gaimard, 1833)] and related genera, from the Paleocene to the Recent of New Zealand and Australia Table 2 List of the nominal species of Lirabuccinum. L. dirum (Reeve, 1846) (type): Pleistocene to Recent, northeastern Pacific. L. brannert (Clark & Arnold, 1923): early Miocene (Sooke For- mation, British Columbia). L. constrictum (Dall, 1918): Recent, Korea. L. coreanicum (Smith, 1875): Pliocene to Recent, East Asia. L. dalli (Clark, 1918): Oligocene (San Ramon Sandstone, Cali- fornia). L. dirum miocenicum (Etherington, 1931): late Miocene (Empire Formation, Washington). L. decessor (Yokoyama, 1928): Miocene (Moriya Formation) Pliocene or early Pleistocene. L. japonicum (Yokoyama, 1926): Pliocene or early Pleistocene (Sawane and Omma formations). L. kavranense (Sinelnikova in Gladenkov et al., 1984): early Mid- dle Miocene (Ilinsk Suite, Kamchatka). L. modestum (Gould, 1846): Pliocene or early Pleistocene to Re- cent, Japan. L. portolaense (Arnold, 1908): Pliocene (Etchegoin and Purisima formations, California). L. sp. of Amano, 1983: early Miocene (Togeshita Formation, Hokkaido). (PONDER, 1973; BEU & MAXWELL, 1990); Lirabuccinum, from the Oligocene to the Recent of the North Pacific; and the North Atlantic genera in the complex of Scalaspira, Searlesia, and Euthria. POWELL (1951) further includes in his Buccinulidae almost all other cool-water Southern- Hemisphere buccinids. Lirae occur in Buccinulum, Si- phonalia, Kelletia, Penion, and Lirabuccinum, among others, but not in the Atlantic complex discussed above under Searlesia, nor in most cold southern forms. With a few exceptions, “‘buccinulid” genera are constant with respect to the presence or absence of lirae. The exceptions occur in the tropical deep-sea genera Manaria Smith, 1906 [type species: M. thurstoni Smith, 1906], most of whose species are lirate, and Eosipho Thiele, 1929 [type species: E. smithi (Schepman, 1911)], most of which lack lirae (see BOUCHET & WAREN, 1986). Generic assignments in Manaria and Eosipho were regarded by BOUCHET & WAREN (1986) as tentative. Although a close relationship may exist between lirate and nonlirate genera, such as Buccinulum and Eu- thria (PONDER, 1971), it is possible that the lirate condition was stable once it evolved. Such a scenario could, for ex- ample, support PONDER’S (1973) contention that the lirate Penion and Kelletia are closely related, and support POWELL’S (1951) hypothesis that Searlesia dira (= Lira- buccinum) is derived from a Southern-Hemisphere stock perhaps related to Buccinulum. Alternatively, there could be a link between Lirabuccinum and Siphonalia. Until we know more about phylogenetic relationships within the Buccinidae, nothing definitive can be said about how close- ly related Livabuccinum is to Searlesia. However, given that several morphologically similar lirate groups occurred in the Pacific before the time of origin of Lirabuccinum, and Page 270 that many nonlirate taxa from which Searlesia could be derived were present in the Atlantic at or before the time of origin of Searlesia, I suggest that Lirabuccinum and Sear- lesia evolved independently within their respective oceans. Similarly, it is unnecessary to link the smooth-lipped east- ern Pacific Calicantharus and Eosiphonalia Ruth, 1942 [type species: E. washingtonensis (Weaver, 1916); Paleogene of Washington, Oregon, and California] with Livabuccinum. Given the far-reaching similarity in form and sculpture between European and North Pacific species previously included in Searlesia, some investigators might elect to per- petuate the status quo notwithstanding the small but con- sistent differences between Searlesia s.s. and the new genus Lirabuccinum. If this course were followed, however, the name of the inclusive genus could not be Searlesia because, as argued above, the immediate likely ancestors of the Pacific and Atlantic groups are best allocated to such gen- era as Buccinulum, Siphonalia, and Euthria. If Searlesia s.s. arose from Euthria-like ancestors with a nonlirate aper- ture, and if Lirabuccinum came from a lirate Buccinulum- like group, one could unite the Pacific and Atlantic branch- es in Buccinulum s.l., of which Euthria would be a distinct subgenus. The precise choice of names is, I believe, less important than the argument that the North Pacific and North Atlantic species previously brought together under Searlesia represent two independent lineages. The estab- lishment of the genus-level taxon Lirabuccinum more ac- curately reflects this hypothesis of independent descent than do other possible schemes of classification. The clarification of the relationships and taxonomy of Searlesia and Lirabuccinum is of more than routine bio- geographical interest. As conceived by DALL (1916, 1918) and most other authors, Searlesia had representatives in both the North Pacific and North Atlantic oceans. Given that Searlesia in Europe was known only from the Pliocene and that Searlesia in the Pacific was soon discovered to extend back to the Miocene and Oligocene, Searlesia has been regarded as an invader from the Pacific to the Atlantic via the Arctic (DAVIES, 1929; DURHAM & MACNEIL, 1967; VERMEIJ, 1989). The reinterpretation advocated here rad- ically revises this biogeographical history. Neither the true Atlantic Searlesia nor the convergent Pacific Lirabuccinum participated in the trans-Arctic interchange, and there was no geographical restriction of Searlesia to the Pacific as VERMEI]J (1989) inferred. Instead, the two groups evolved independently and remained confined to the Pacific and Atlantic basins. Both groups can be traced back to the Oligocene. Searlesia apparently became extinct at the end of the Pliocene in Europe, whereas Lirabuccinum is still living, being represented by vicariant species on the Amer- ican and Asian sides of the temperate North Pacific. ACKNOWLEDGMENTS I thank R. Janssen for information concerning Searlesia mitgaui; A. W. Janssen for allowing me to borrow material of Searlesia and Pirgos from the NMNH in Leiden; D. R. The Veliger, Vol. 34, No. 3 Lindberg for access to the collections at UCB; P. Rodda for arranging access to CAS; T. R. Waller and W. Blow for access to type material at USNM; and A. Warén and M. G. Harasewych for their valuable comments on the manuscript. Photographs in this paper were kindly taken by M. Graziose, and Janice Cooper provided technical and editorial assistance. LITERATURE CITED AppicoTT, W. O. 1970. Miocene gastropods and biostratig- raphy of the Kern River area, California. United States Geological Survey Professional Paper 642:1-174. ADEGOKE, O. S. 1969. Stratigraphy and paleontology of the marine Neogene formations in the Coalinga region, Cali- fornia. University of California Publications in Geological Sciences 80:1-241. AMANO, K. 1983. 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United States Geological Survey Professional Paper 222:1-185. YOKOYAMA, M. 1926. Fossil shells from Sado. Journal of the Faculty of Science, Imperial University, Tokyo (section 2) 1(8):249-312. The Veliger 34(3):272-290 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Four New Species and a New Genus of Opisthobranch Gastropods from the Pacific Coast of North America TERRENCE M. GOSLINER Department of Invertebrate Zoology and Geology, California Academy of Sciences, Golden Gate Park, San Francisco, California 94118, USA Abstract. This paper describes four new species of opisthobranchs from the eastern Pacific. Runcina macfarlandi is described from Oregon and may also be known as far south as Monterey Bay, California. Baptodoris mimetica is known from Monterey Bay, south to Isla San Martin, Baja California. This represents the first record of the genus from eastern Pacific waters. Noumeaella rubrofasciata is described from southern California south to Islas San Benitos, Baja California. Anetarca gen. nov., with type species A. armata, is described from the Pacific coast of central Baja California. INTRODUCTION The opisthobranch fauna of the Pacific coast of North America has been well studied (MACFARLAND, 1966; BEH- RENS, 1980; McDONALD & NYBAKKEN, 1980; Mc- DONALD, 1983). Despite the fact that the fauna has been extensively surveyed, additional species continue to be de- scribed (MILLEN, 1986, 1987; GOSLINER & BEHRENS, 1986; BEHRENS, 1987; BEHRENS & GOSLINER, 1988a, b; GOSLINER & BERTSCH, 1988). Additional recent collections continue to yield undescribed species. This paper describes four additional species of opisthobranchs from the eastern Pacific. All four of these species are placed in genera that have no previously described representatives recorded from the eastern Pacific. The systematic relationships and bio- geographical affinities of these species are discussed. SPECIES DESCRIPTIONS Order Cephalaspidea Family RUNCINIDAE H. & A. Adams, 1854 Genus Runcina Forbes & Hanley, 1853 Runcina macfarlandi Gosliner, sp. nov. (Figures 1A, 2, 3) Type material: Holotype, California Academy of Sci- ences, San Francisco, CASIZ 074572, found on submerged tips of Cladophora trichotoma (C. A. Agardh) Kutzing, in high intertidal pools, Seal Rock State Park, Seal Rock, Lincoln County, Oregon, 9 July 1990, Cynthia Trow- bridge. Paratype, dissected, CASIZ 074573, same date and locality as holotype. Paratype, CASIZ 074574, dissected, same locality as holotype, 20 June 1990, Cynthia Trow- bridge. Distribution: Runcina macfarlandi has been collected from two localities within Lincoln County Oregon (Cythia ‘Trowbridge, personal communication), Boiler Bay State Park, north of Depoe Bay, south to Seal Beach State Park, near Seal Beach. This species probably has also been col- lected from the central California coast (see Discussion). Etymology: This species is named for the late Frank Mace MacFarland, who pioneered studies of eastern Pacific opis- thobranchs. He also first illustrated a specimen of a species of Runcina collected from Pacific Grove in 1899. In all probability this is the species described here. External morphology: Living animals (Figures 1A, 2A) are 3-5 mm in length. The notum is yellowish brown with darker brown to black pigment in the central portion of the body. The head shield is flattened anteriorly and wid- ens into the broad ovoid body. Posteriorly the ctenidium consists of two simple, rounded plicae, which are well separated from each other. The eyes are visible along the anterolateral sides of the body, between the notum and the foot. A sperm groove traverses the right side of the body from the hermaphroditic gonopore near the posterior end to the penial aperture on the anterolateral end of the body. Figure 1 Living animals. A. Runcina macfarlandi sp. nov. B. Baptodoris mimetica sp. nov. C. Noumeaella rubrofasciata sp. nov. D. Anetarca armata gen. et sp. nov. Page 274 D The Veliger, Vol. 34, No. 3 Figure 2 Runcina macfarlandi sp. nov. A. Dorsal view of living animal: a, anus; ct, ctenidium; scale = 1 mm. B. Central nervous system: cpl, cerebral pleural ganglion; pe, pedal ganglia; sbv, subintestinal-visceral ganglion; sp, suprain- testinal ganglion; scale = 0.25 mm. C. Digestive tract: a, anus; bm, buccal mass; ca, caecum; dg, digestive gland; gi, gizzard; gm, genital mass; p, penis; pt, ptyaline gland; scale = 0.5 mm. D. Reproductive system: albme, albumen- membrane glands; am, ampulla; bc, bursa copulatrix; gp, genital pore; mu, mucous gland; scale = 0.25 mm. E. Penis: pp, penial papilla; pr, prostate; scale = 0.25 mm. Digestive tract (Figure 2C): The buccal mass is short and muscular. Within the mass, near its anterior end is a thin labial cuticle that had no obvious chitinous jaw rodlets. More posterior is the radula (Figure 3A) with a formula of 19-21 x 1-1-1-, in two specimens examined. The ra- chidian teeth (Figure 3B) are broad, with a pair of elon- gate, posteriorly directed limbs. The masticatory edge con- tains a pair of rounded, denticulate pads on either side of the small central denticle. Each of these rounded cutting surfaces bears 5-11 elongate denticles. The lateral teeth (Figure 3C) are elongate and curved. The masticatory border is entirely smooth, without any trace of denticles. Posterior to the buccal mass, the esophagus narrows and contains a large, saccate caecum. The posterior end of the esophagus enters the muscular gizzard. The gizzard is larger than the buccal mass. Four longitudinally directed gizzard plates are contained within the gizzard. Each chi- tinous plate (Figure 3D) contains 6 or 7 denticulate trans- verse ridges. Posteriorly, the gizzard is connected to the large, lobate digestive gland. From the digestive gland, a narrow intes- tine emerges and empties into the anus at the posteromedial end of the body. A simple ptyaline gland is present adjacent to the intestine and exits into the anus. T. M. Gosliner, 1991 Page 275 BOK a9n6o2 15KY x4 Figure 3 Runcina macfarlandi sp. nov. Scanning electron micrographs. A. Entire width of radula. B. Rachidian teeth. C. Lateral teeth. D. Gizzard plate. Page 276 The Veliger, Vol. 34, No. 3 Table 1 Morphological variation in the Runcinidae. Radular Giz- Genus Shell Gill formula Rachidian Laterals zard Runcina Forbes, 1851 present or absent 2 or 3, right side 1.1.1. denticulate denticulate or smooth present Ildica Bergh, 1889 present, external plicate, right side 1.1.1. smooth smooth present Metaruncina Baba, 1967 present plicate, right side reduced reduced reduced present Runnica Miller & Rudman, 1968 present plicate, right side 1.1.1 denticulate short, smooth present Runcinella Odhner, 1924 absent 5 circular plicae 2.1.2. denticulate outers bifid present Runcinida Burn, 1963 absent 5 linear plicae 1.1.1. denticulate smooth present Ilbia Burn, 1963 absent absent 1.1.1. trifid denticulate absent Pseudoilbia Miller & Rudman, 1968 absent absent 2.0.2. absent unequal, denticulate absent Lapinura Marcus & Marcus, 1970 present, external Central nervous system (Figure 2B): The central system surrounds the esophagus, posterior to the buccal mass. The highly cephalized system is formed of four distinct ganglia. A pair of large cerebral ganglia are separated by a short cerebral commissure. The paired pedal ganglia are situated below the esophagus and are separated from each other by a short commissure. On the left side of the nerve ring is a smaller ganglion representing the fusion of the left pleural and supraintestinal ganglia. On the right side, the right pleural ganglion, supraintestinal, and visceral gan- glia have fused to form another small ganglion. No distinct visceral loop was observed. Reproductive system (Figure 2D): The reproductive sys- tem is monaulic. The short saccate ampulla narrows and enters the female gland mass between the mucous and albumen glands. The female glands exist at the gonopore adjacent to the duct of the spherical bursa copulatrix. The penis (Figure 2E) is thin and elongate. The pos- terior end curves under the ventral surface of the gizzard. The posterior three-fourths of the penis is composed of the indistinct prostate and spermatic bulb. The penis proper consists of a simple, poorly developed papilla, which is devoid of any armature. Discussion: The Runcinidae have been subdivided into as many as nine genera by various authors (Table 1). These genera are separated largely on the basis of differences in the arrangement and structure of the ctenidium, formula and shape of the radular teeth, and presence or absence of a shell and gizzard plates. Other than Runcina, all other genera contain only a single species. CLARK (1984) con- siders Lapinura Er. Marcus & Ev. Marcus, 1970, as a junior synonym of Runcina. THOMPSON & BRODIE (1988) considered Runnica Miller & Rudman, 1968, to be a junior synonym of Runcina. Based on this synonymy, they con- sidered Runcina to include 14 nominal species. GOSLINER (1990) discussed problems related to the systematics of eastern Atlantic species of Runcina and suggested possibly synonyms. Certainly, more extensive study of the Runcin- idae is required to determine the range of variability of genera and their phylogenetic relationships. plicate, right side 1.1.1. denticulate smooth present Among described runcinids, Runcina macfarlandi is the only species known to possess a single flattened branchial plica on either side of the anus. In other aspects of its anatomy, it does not differ markedly from other species currently placed in the genus Runcina. Rather than erect yet another monotypic genus, I prefer to place the present species in the genus Runcina. Of described species of Run- cina, only R. marshae Burn, 1966, is similar to R. mac- farlandi in having a yellow ground color. However, the rachidian teeth of R. marshae are not strongly bilobed, as in R. macfarlandi. Also the gizzard plates of R. marshae are more highly denticulate than in R. macfarlandi. Specimens of runcinids have previously been collected from the coast of California. In MacFarland’s original field notes (housed at the California Academy of Sciences), I have located an illustration of a runcinid collected from Pacific Grove on 12 August 1899. The animal is similar in color and shape to the present species. No other details of the anatomy of this animal are known and no specimens have been found in the MacFarland Collection at the Cal- ifornia Academy of Sciences. GOSLINER & WILLIAMS in Smith & Carlton, 1975, listed a yellow Runcina from Pa- cific Grove. This record was based on specimens that Peter Glynn collected and Michael Ghiselin identified from Hopkins Marine Station. Attempts to find other material from the Monterey Peninsula have been unsuccessful to date. It is likely, however, that specimens collected from these localities are conspecific with the present species. Order Nudibranchia Suborder Doridacea Family DiscoDoRIDAE Bergh, 1891 Genus Baptodoris Bergh, 1884 Baptodoris mimetica Gosliner, sp. nov. (Figures 1B, 4-6) Type material: Holotype, California Academy of Sci- ences, San Francisco, CASIZ 074575, intertidal zone, As- ilomar State Park, Pacific Grove, California, 6 July 1986, T. M. Gosliner, 1991 Page 277 y 7 ’ . - S Pen / on q of ; . 5 f 5] : sd boa6as isky & a9a6e7 15KY kige Figure 4 Baptodoris mimetica sp. nov. Scanning electron micrographs of notal structures. A. Surface view of caryophyllidia. B. Cross section of caryophyllidium. C. Cross section of notum. Page 278 The Veliger, Vol. 34, No. 3 Figure 5 Baptodoris mimetica sp. nov. A. Reproductive system: alb, albumen gland; am, ampulla; bc, bursa copulatrix; ej, ejaculatory portion of vas deferens; me, membrane gland; mu, mucous gland; pr, prostatic portion of vas deferens; rs, receptaculum seminis; v, vagina; vg, vestibular gland; scale = 0.5 mm. B. Ventral view of animal showing head and anterior end of foot: scale = 3 mm. C. Distal end of vas deferens and penis: ej, ejaculatory duct; gp, gonopore; scale = 0.5 mm. Gary McDonald. Paratypes, two specimens, CASIZ 074576, south storage tank, Long Marine Laboratory, Santa Cruz, California, 5 October 1983, G. McDonald. Paratype, dissected, CASIZ 074577, south storage tank, Long Marine Laboratory, Santa Cruz, California, 5 Oc- tober 1983, G. McDonald. Paratype, dissected, CASIZ 074578, Long Marine Laboratory, Santa Cruz, Califor- nia, October 1989, G. McDonald. Paratype, CASIZ 072093, Monastery Beach, Carmel, California, 5 October 1975, Andrea Purdue. Paratype, CASIZ 069142, 6 m depth, Monastery Beach, Carmel California, 6 March 1976, A. K. McDonald. Paratype, CASIZ 072094, Mon- T. M. Gosliner, 1991 Page 279 Figure 6 Baptodoris mimetica sp. nov. Scanning electron micrographs of radula. A. Innermost radular teeth. B. Outermost radular teeth. astery Beach, Carmel, California, 25 November 1970, Ed Stark. Paratype, dissected, CASIZ 074579, Isla San Mar- tin, Baja California, David Behrens. Distribution: This species has been collected from Santa Cruz, California, to Isla San Martin, off the Pacific coast of Baja California, Mexico. Etymology: The epithet mimetica refers to the striking external similarity between this species and the common sympatric dorid nudibranch Doriopsilla albopunctata (Coo- per, 1863). External morphology: The living animals (Figure 1B) reach 25 mm in length. The ground color is bright lemon yellow. Small opaque white spots are uniformly scattered over the dorsal surface of the notum. The rhinophores are uniformly brown. The gills are translucent white. The notum is finely studded with minute caryophyllidia. When examined under the scanning electron microscope, these caryophyllidia are 30-50 um in diameter. Each car- yophyllidium (Figure 4A) is supported by a ring of 7-12 calcareous spicules. In the center is a mound covered by dense cilia. The structure of the caryophyllidia is very similar to that described by KREss (1981) and FOALE & WILLAN (1987) for species of Rostanga and Jorunna. The supporting spicules of the caryophyllidia penetrate deeply into the notal tissue (Figure 4B). The rigid notum contains a dense mat of calcareous spicules (Figure 4C). The rhinophores are perfoliate with 14 closely spaced lamellae. The branchial plume consists of 7 or 8 bipinnate gills. The gills are held erectly when fully extended. The anus is situated within the center of the branchial plume. The head (Figure 5B) is well developed, with paired labial tentacles. The foot is broad, and bilabiate anteriorly. The posterior end of the foot is rounded and extends beyond the posterior limit of the notum. The genital aperture is situated between the ventral portion of the notum and the foot, approximately one-third of the body length behind the head. Buccal mass: The buccal mass is large and muscular. The anterior portion of the mass is lined with a thick labial cuticle, which is devoid of any jaw rodlets. More poste- riorly, is the radula, with a formula of 38 x 51-0-51- and 41 x 52-0-52- in two specimens observed. The rachis lacks a rachidian row of teeth. The inner lateral teeth (Figure 6A) are simply hamate. They are devoid of any denticles. The laterals from the middle of the half row are larger Page 280 than the inner ones and have a more elongate cusp. The outermost laterals (Figure 6B) are short and flattened, with a finely serrate masticatory border. The two teeth im- mediately inward from these two (Figure 6C) are typically hamate, but bear 2 or 3 denticles on their outer edge. Reproductive system (Figure 5A, C): The arrangement of the reproductive organs is triaulic. The ampulla is elon- gate and slightly curved. At its distal end, the ampulla divides into a short oviduct and the vas deferens. The oviduct is short and enters the female gland mass between the albumen and membrane glands. The mucous gland is massive with several lobes. It terminates at the nidamental opening, immediately ventral to the common atrium of the vas deferens and vagina. At the junction of the ampulla, vas deferens, and oviduct is the uterine duct. After a short distance, it branches to the duct of the spher- ical receptaculum seminis. The uterine duct curves and joins the base of the pyriform bursa copulatrix. From this junction the thin, convoluted vagina extends distally. At its distal end it expands into a vaginal atrium, which joins with a large lobate vestibular gland. The vas deferens expands immediately into the massive prostate. The prostate narrows into a convoluted ejacu- latory segment, which gradually widens. The muscular portion of the ejaculatory duct empties into a tubular sec- tion with a chitinous lining (Figure 5C). The proximal portion of this segment is lined with four rows of minute chitinous hooks. This area widens into a section without armature. More distally is a segment with four shorter rows of larger spines. Immediately distal to this point the duct widens markedly. On one side of the duct is a swollen muscular pouch, which bears a single large chitinous spine with a curved apex. Discussion: The generic distinctions within the Disco- dorididae are the subject of considerable confusion. More than 30 genera have been included within the family by various workers (THIELE, 1931; FRANG, 1968). Many gen- era are monotypic and are known only from the original descriptions, which are often incomplete. Members of the family appear to be united by several apomorphic features. All species appear to have digitiform labial tentacles, an anteriorly divided foot, and a thick, well-developed pros- tate. Other features vary within and between genera. The notum may be composed of simple tubercles or complex caryophyllidia. Presence or absence of caryophyllidia may vary within a single genus, such as Sclerodoris Eliot, 1904 (RUDMAN, 1978). Jaw rodlets may be present or absent in a single genus, such as /orunna Bergh, 1876 (Ev. Marcus, 1976). Outer radular teeth may be denticulate or simply hamate within a single genus, as in Halgerda Bergh, 1880 (RUDMAN, 1978). A vestibular gland and penial spines may be present or absent in species of Sclerodoris (KAY & YOUNG, 1969; RUDMAN, 1978). Many of the described genera appear to be paraphyletic or are based solely on plesiomorphic features (e.g., Discodoris The Veliger, Vol. 34, No. 3 Bergh, 1877). Revision of the systematics of the crypto- branch dorids must await detailed evaluation of characters, their polarity and phylogeny. Until this is achieved, place- ment of taxa within genera must be regarded as tentative. The present species is placed within the genus Baptodoris Bergh, 1884, based on its similarity to the type species, B. cinnabarina Bergh, 1884. The genus is characterized by having a firm, finely spiculose notum, digitiform labial tentacles, a labial cuticle without rodlets, and penial ar- mature with numerous hooks. SCHMEKEL (1970) further described the reproductive anatomy of B. ciznnabarina. This species has numerous rows of spines lining the distal por- tion of the vas deferens and has a single larger penial spine. It also has an expanded vaginal atrium with an adjacent vestibular gland. Baptodoris mimetica differs from B. cinnabarina in sev- eral significant regards. The ground color of the present species is yellow rather than scarlet. The radular teeth of B. cinnabarina are all narrow and hamate, without den- ticles. In B. mimetica the hamate teeth are broader and the outer ones are denticulate and serrate. The penial spines of B. mimetica are more numerous and complex in their arrangement. Llera & Ortea in ORTEA et al. (1982) described Bap- todoris perezi from the Canary Islands and reviewed the other members of the genus. Like B. mimetica, B. perezi is yellow, but has black rather than yellowish spots. Bap- todoris perezi has unipinnate rather than bipinnate gills. In this species, caryophyllidia are restricted to the margins of the notum rather than being evenly scattered. In B. perezi, the radular teeth are simply hamate, without den- ticles or serrations. This species also lacks a vestibular gland. Baptodoris fongosa Risbec, 1928, known only from its original description from New Caledonia, is reddish yellow with gray patches. Its outer four teeth per half row are finely serrate, while in B. mimetica only the outer two teeth are serrate. A vestibular gland was not described. Baptodoris tuberculata Bergh, 1888a, described from Thailand, is poorly known. All of its radular teeth are hamate, without denticles, except for some of the outermost teeth, which are bifid. A penial gland is present at the gonopore. OrTEA, et al. (1982) also considered Aporodoris rubra Bergh, 1905, as a species of Baptodoris. In this species the outer four teeth are finely serrate. The anatomy of Baptodoris fongosa, B. tuberculata, and B. rubra must be more completely described before they can be adequately compared with other described disco- dorids. Clearly though, enough is known about these taxa to distinguish them from B. mimetica. Gargamella Bergh, 1894, contains two described and two undescribed species that share most of the features listed above for Baptodoris cinnabarina (see ODHNER, 1926; ER. Marcus, 1959; GOsLINER, 1987). The only significant difference between species of this genus and those included T. M. Gosliner, 1991 in Baptodoris is that the vestibular duct is present on the vas deferens rather than on the vaginal duct. On this basis, one might seriously question the homology of these struc- tures. Further study is required to verify the location of these vestibular glands and to examine details of their histology and function. Species of Platydoris Bergh, 1877, also have spines lining the vas deferens (KAY & YOUNG, 1969; EDMUNDS, 1971). Their vestibular gland enters the vas deferens, as in Gar- gamella, rather than entering the vagina. Externally, mem- bers of Platydoris differ from species of both Baptodoris and Gargamella, as they are dorsoventrally flattened and lack caryophyllidia. Baptodoris mimetica closely resembles Doriopsilla al- bopunctata (Cooper, 1863) and other conspecific species of porostomes, whose systematic status remains unclear, in its external morphology and coloration. Living animals of the two species can be readily distinguished. Doriopsilla albopunctata has a soft fleshy texture, whereas B. mimetica is rigid and is finely covered with caryophyllidia. The gills of D. albopunctata are more highly pinnate and cover more of the notum when fully extended. The gills of B. mimetica are held more erectly than those of D. albopunctata. Ven- trally, B. mimetica has elongate digitiform labial tentacles, whereas in D. albopunctata and other porostomes, rudi- mentary tentacles are present on either side of the mouth. Suborder Aeolidacea Family FACELINIDAE Bergh, 1889 Subfamily FAVORININAE Bergh, 1889 Genus Noumeaella Risbec, 1937 Noumeaella rubrofasciata Gosliner, sp. nov. (Figures 1C, 7, 8) Type material: Holotype, California Academy of Sci- ences, San Francisco, CASIZ 074580, 20 m depth, S end of Isla San Benito Oeste, Baja California, 17 August 1987, T. M. Gosliner. Paratype, dissected, CASIZ 074581, same date and locality as holotype. Paratype, CASIZ 074582, same date and locality as holotype. Paratype, CASIZ 074583, Isthmus Cove, Santa Catalina Island, California, 10 October 1985, James Morin. Paratype, CASIZ 074027, under rock, 2-4 m depth, near point in front of Hotel Punta Colorada, Punta Colorada, Gulf of California, Baja California Sur, Mexico, 15 November, 1972, Antonio J. Ferreira. Distribution: This species has been found along the Cal- ifornia coast from Santa Barbara Island (Marc Cham- berlain, personal communication) and Santa Catalina Is- land (present study). It has also been found from the Pacific coast of Mexico from Islas San Benitos (present study) and from Punta Colorada, Baja California Sur, in the Gulf of California (present study). Page 281 Etymology: The epithet rubrofasciata refers to the red- dish stripe present on the middorsal portion of the head. External morphology: The living animals (Figure 1C) reach 8 mm in length. The ground color is translucent white. Most of the dorsal and lateral surfaces of the body are covered with dense opaque white. The base and apex of the rhinophores, the basal one-fourth of the oral ten- tacles, and the sides and bottom of the foot are the only areas that are translucent white. A red-orange stripe ex- tends middorsally from the anterior limit of the head to the anterior limit of the rhinophores. The base of each ceras is opaque white. Above the base, the cerata are trans- lucent and the brick-red digestive gland is visible. The large cnidosac is deep red-orange. The body is thin and elongate (Figure 7A). The foot is approximately equal in width to the notum and tapers to an elongate, posterior tail. The rhinophores (Figure 7B) are widest in the middle and taper to an elongate apex. Their posterior surface bears numerous, elongate papillae. The narrow and acutely pointed oral tentacles are about twice as long as the rhinophores. The anterior ends of the foot form elongate tentacles, which are sharply recurved when the animal is actively crawling. The cerata are short and somewhat inflated in appearance. They are widest in their distal third. The cnidosac is large and conical in shape. The cerata are arranged in a series of 5-7 horseshoe- shaped arches on either side of the body. The single pre- cardiac arch contains 6-9 cerata in the four specimens examined. The first postcardiac arch contains 5-7 cerata. The subsequent arches contain fewer cerata posteriorly and are each composed of 1-6 cerata. The anus is cleio- proctic, located on the right side of the body, within the first postcardiac ceratal arch. The nephroproct is located within the interhepatic space. The gonopore is situated below the anterior limb of the anteriormost ceratal arch. Buccal mass: The buccal mass is short and muscular. A lobate oral gland is present on either side of the buccal mass (Figure 7C). Each gland extends posteriorly for about two-thirds of the length of the buccal mass. Within the mass are the paired chitinous jaws (Figure 7D). The mas- ticatory border of the jaw is of moderate length (Figure 8A) and bears 5 or 6 rows of irregular denticles (Figure 8B). The outermost denticles are irregularly divided into 4 or 5 apices while those of the inner 4 or 5 rows have a simple acute apex. The radular formula in the one specimen examined was 14 x 0-1-0. The radular teeth (Figure 8C, D) are broadest posteriorly. The posterior limbs of the teeth are acutely pointed and evenly arched. The central cups is narrow but wider and more elongate than the adjacent denticles. There are 7-9 elongate, inwardly curved denticles on either side of the central cusp. Reproductive system (Figure 7E, F): The arrangement of the organs is androdiaulic. The ampulla is thin and Page 282 The Veliger, Vol. 34, No. 3 Figure 7 Noumeaella rubrofasciata sp. nov. A. Lateral view of preserved specimen: scale = 1 mm. B. Rhinophore: scale = 0.25 mm. C. Buccal mass: og, oral gland; scale = 0.25 mm. D. Jaw: scale = 0.5 mm. E. Reproductive system: alb, albumen gland; am, ampulla; bc, bursa copulatrix; me, membrane gland; mu, mucous gland; pr, prostatic portion of vas deferens; rs, receptaculum seminis; scale = 0.25 mm. F. Penis: pp, penial papilla; scale = 0.125 mm. slightly coiled. Distally, the ampulla narrows and bifur- cates into the oviduct and vas deferens. The oviduct is narrow and expands into a partially serial pyriform re- ceptaculum seminis. The oviduct again narrows immedi- ately before its entrance into the bilobed albumen gland. The lobate membrane gland is adjacent to the albumen gland. The mucous gland is the largest portion of the reproductive system and consists of three major lobes. The mucous gland terminates at the common gonopore. The elongate duct of the thin-walled bursa copulatrix joins the T. M. Gosliner, 1991 Page 283 B9B607 15K ki Figure 8 Noumeaella rubrofasciata sp. nov. Scanning electron micrographs. A. Masticatory border. B. Denticles of masticatory border. C and D. Radular teeth. Page 284 mucous gland near the gonopore. The vas deferens grad- ually expands into a curved prostatic portion, which again gradually narrows into the simple, elongate penial papilla. The papilla lacks any armature or glands. Discussion: The present species is clearly placed within the Facelinidae and included with the Favorininae on the basis of its cleioproctic anus, cerata all included in arches, and cuspidate radular teeth. Only members of three genera of favorinids—Noumeaella Risbec, 1937, Palisa Edmunds, 1964 and Jason Miller, 1974—include species with pa- pillate rhinophores. WILLAN (1987) discussed character polarities of prim- itive and derived features within the Facelinidae. On the basis of this discussion and the incorporation of other fea- tures not included by Willan, it is clear that Noumeaella rubrofasciata differs markedly from other facelinids with papillate rhinophores. Moridilla brocku Bergh, 1888b, dif- fers from the present species in that all of the cerata are arranged in linear rows rather than in arches. Jason mi- rabilis Miller, 1974, has a vestigial radula consisting of only five teeth, some cerata arranged in arches with two rather than one row of cerata, and a penial papilla with apical glands. Members of the genera Noumeaella Risbec, 1937, and Palisa Edmunds, 1964, are most similar to the present species. Noumeaella includes four species (N. cu- riosa Risbec, 1937, N. rehderi Er. Marcus, 1965, N. isa Ev. Marcus & Er. Marcus, 1970, N. africana Edmunds, 1970), and all are known only from the Indo-Pacific trop- ics. Palisa contains only a single species, P. kristenseni (Ev. Marcus & Er. Marcus, 1963), which is considered a senior synonym of P. papillata Edmunds, 1964 (EDMUNDS & Just, 1983). All of these species share several derived features: papillate rhinophores, cerata arranged in arches with only a single row, and a well-developed prostatic vas deferens. The only difference between Noumeaella and Pal- isa is that P. kristenseni has more precardiac cerata and an unarmed penis. Because both of these features of Palisa are plesiomorphic, there are no autapomorphies to distin- guish it from Noumeaella. On this basis, and by the rule of priority, Palisa is considered a junior synonym of Nou- meaella. Noumeaella rubrofasciata can be readily separated from the other described species of the genus by its unique color pattern with red pigment and by several aspects of its internal anatomy. In N. rubrofasciata there are two ple- siomorphic features not found in other members of the genus: the masticatory border of the jaw bears several rows of denticles, and a distinct distal bursa copulatrix is present adjacent to the gonopore. EDMUNDS (1970: fig. 20B) il- lustrated a structure called a bursa copulatrix in N. afri- cana. However, this structure is contiguous with the serial receptaculum seminis along the oviduct, prior to its en- trance into the female gland mass. It is, therefore, not considered to be homologous with a bursa situated at the gonopore, which is characteristic of N. rubrofasciata and most other opisthobranchs. Noumeaella rubrofasciata has The Veliger, Vol. 34, No. 3 one apomorphic feature not known in other members of the genus: the gonopore is situated anterior to the precar- diac ceratal arch, rather than posterior to it, as in the remaining members of the genus. The radular teeth of N. rubrofasciata are more similar to those of N. africana and N. kristenseni, where the lateral denticles are deeply in- cised. Family FACELINIDAE Anetarca Gosliner, gen. nov. Diagnosis: Body with broad foot. Rhinophores smooth. Foot corners tentacular. Precardiac cerata arranged in arch containing a single row of cerata. Postcardiac cerata ar- ranged in simple rows. Anus cleioproctic, situated between first two postcardiac ceratal rows. Nephroproct situated within interhepatic space. Gonopore ventral to precardiac ceratal arch. Salivary glands simple. Oral glands dorsal. Masticatory border of jaws smooth. Radular teeth with numerous lateral denticles and prominent central cusp. Reproductive system androdiaulic with semiserial recep- taculum seminis. Bursa copulatrix absent. Penis with pos- teriorly directed, subterminal spine. Type species: Anetarca armata Gosliner, sp. nov. Etymology: Anetarca is derived from the reversal of the letters forming the genus Cratena Bergh, 1864, to which the new genus appears to be allied. The letter “a” was added to the end of the name for euphony. BURN (1969) described Sclerodoris tarka based on the Australian aborigi- nal word tark, for a spear. In the present genus, the tarc portion of the name also refers to apical penial spine. Anetarca armata Gosliner, sp. nov. (Figures 1D, 9-11) Type material: Holotype, California Academy of Sci- ences, San Francisco, CASIZ 074067, intertidal zone, S of Punta Asuncion, Baja California Sur, 2 July 1984, Robert Van Syoc. Paratype, CASIZ 074584, same date and locality as holotype. Paratype, dissected, CASIZ 074585, same date and locality as holotype. Distribution: This species is known only from the type locality along the northern Pacific coast of Baja California Sur. Etymology: The specific epithet, armata, refers to the presence of a posteriorly directed penial spine, which dis- tinguishes this species. External morphology: The living animals (Figures 1D, 9A) reach 14 mm in length. The general body color is translucent reddish orange. Almost the entire body surface is mottled by patches of opaque cream-white. The size and density of the patches are extremely variable within a single individual. The rhinophores are largely devoid of opaque patches and are a deeper orange than the rest of T. M. Gosliner, 1991 Page 285 Figure 9 Anetarca armata gen. et sp. nov. A. Dorsal view of living animal: scale = 2 mm. B. Lateral view of preserved animal showing arrangement of cerata: scale = 2 mm. C. Ventral view of head and foot: scale = 2 mm. D. Buccal mass: bm, buccal mass; og, oral gland; scale = 0.5 mm. E. Reproductive system: alb, albumen gland; am, ampulla; fa, female aperture; me, membrane gland; mu, mucous gland; p, penis; rs, receptaculum seminis; scale = 0.5 mm. Page 286 The Veliger, Vol. 34, No. 3 G69 15KY x1, Figure 10 Anetarca armata gen. et sp. nov. Scanning electron micrographs. A. Jaw. B. Older radular teeth. C. Newer radular teeth. T. M. Gosliner, 1991 Page 287 Ag nogead 1SKY x7. GK Figure 11 Anetarca armata gen. et sp. nov. Scanning electron micrographs. A. Penis. B. Penial spine. C. Apex of penial spine. Page 288 the body. Opaque pigment is present on the head, the oral tentacles, and as irregular transverse bands on the cerata. The head, foot, and notum are broad, giving the animal a robust appearance. The smooth and elongate rhinophores are broadest basally and taper to a narrow apex. The oral tentacles are shorter than the rhinophores and are rela- tively stout. The foot corners (Figure 9B) are elongate and tentacular. The ventral portion of the head is deeply cleft and bilabiate (Figure 9C). The cerata are curved and are cylindrical throughout most of their length, but taper to an acute apex. The precardiac cerata are arranged in a single horseshoe-shaped arch that contains only a single row of cerata (Figure 9B). The postcardiac cerata are arranged in a series of 9 or 10 linear rows. The ceratal formula in one specimen is: I-15, II-7; III-7, IV-7, V-7, VI-6, VII-5, VIII-4, IX-3, X-2, XI-1. The gonopore is situated within the arch of the precardiac cerata. The anus is cleioproctic, situated posterior to the first postcardiac ceratal row. The nephroproct is situated within the inter- hepatic space. Buccal mass: The buccal mass is short and muscular. A series of lobed oral glands is present on the dorsal surface of the buccal mass (Figure 9D). The jaws (Figure 10A) are broad with a moderately long masticatory border. The border is smooth, without any evidence of denticulation. The radular formula is 13 x 0-1-0: in one specimen examined. The teeth are narrow and broadly arched. The central cusp is broad and elongate. On either side of the cusp are numerous elongate denticles. Older teeth (Figure 10B) may have as few as 8 denticles on either side of the cusp, while newer ones (Figure 10C) may have as many as 11 denticles. Reproductive system: The arrangement or organs is an- drodiaulic (Figure 9E). The narrow preampullary duct expands into a curved, saccate ampulla that narrows and divides into a short oviduct and a narrower vas deferens. The oviduct is joined by the thick duct of the semiserial, pyriform receptaculum seminis. Slightly distal to this junc- tion the oviduct enters the female gland mass between the albumen and membrane glands. These two glands are small compared to the lobate mucous gland. The mucous gland terminates at the female gonopore. The vas deferens is narrow proximally and expands into the large penis. There does not appear to be a distinct prostatic region of the vas deferens. The penis curves and enters the penial sac. Within its central portion the narrow penial duct is visible. The penial papilla is curved at its distal apex. At this point the penial duct emerges from the papilla. Near the distal end of the papilla, a chitinous spine is visible (Figure 11A). The spine is sharply curved away from the tip of the penial papilla (Figure 11B). The tip of the penial stylet bears an elongate opening at its apex (Figure 11C), which appears similar to the tip of a hypodermic needle. How the stylet functions is uncertain because it does not appear to be in direct contact with the penial duct. The Veliger, Vol. 34, No. 3 Discussion: The systematic relationships of the Facelin- idae have been reviewed and discussed extensively in recent years (MILLER, 1974, GOSLINER, 1980; EDMUNDs & JUST, 1983; GOSLINER & BEHRENS, 1986; WILLAN, 1987). The family has been divided into subfamilies, largely on the basis of differences in ceratal arrangement (ER. MARCUS, 1958; MILLER, 1974). EDMUNDs (1970) suggested that ceratal arrangement has evolved in a polyphyletic fashion within the family, and GOSLINER (1980) has supported this view. Since then, RUDMAN (1981) studied the clearly mono- phyletic facelinid genus Phyllodesmium. In this genus, monophyly is highly probable, given the several synapo- morphies that unite the species, including absence of cni- dosacs, flattened cerata that readily autotomize, and a spe- cialized diet of alcyonarians. RUDMAN (1981: fig. 27) depicted the ceratal arrangement in the various species he studied. The genus Phyllodesmium includes species that have cerata contained in arches with one or more rows of cerata within the arches. There are also several species that have only a preanal arch, followed by postanal linear rows, as in the genus Cratena Bergh, 1864. Because mem- bers of this single genus exhibit most of the ceratal patterns known for members of the family, there remains no ques- tion that the ceratal patterns have evolved polyphyletically. I agree with WILLAN’s (1987) hypothesis that, within the Facelinidae, having all cerata arranged in linear rows represents the plesiomorphic state, and that having cerata arranged in arches represents a derivation from the prim- itive condition. Whether or not evolution of arches from rows occurred only once in the family remains unresolved. Clearly, arches have arisen from rows on at least one other occasion in the Aeolidiidae (GOSLINER, 1985). I would also suggest that, for species of facelinids with arches, those arches with more than one row of cerata are plesiomorphic and those with a single row of cerata are apomorphic. This is consistent with the general trend within aeolids to reduce ceratal numbers. Also apparent in the Facelinidae has been a reduction of postanal ceratal arches to form secondarily derived linear rows, as has occurred independently in some species of Phyllodesmium and in Cratena. These secondarily derived rows differ from the plesiomorphic arrangement in that single rows are well separated from each other rather than forming clusters of dense rows. This ceratal arrangement, with a preanal arch and sin- gle postanal rows, is also found in Anetarca. Anetarca lacks all of the above-mentioned synapomorphies present in species of Phyllodesmium. Species of Cratena are elongate, slender aeolids, whereas Anetarca armata is stockier. All described species of Cratena have a large penial gland and lack a penial stylet. No penial gland is present in A. ar- mata. Several other genera of facelinids possess a single penial stylet (MILLER, 1974). In Emarcusia Roller, 1972, most species of Noumeaella Risbec, 1937, and one species of Favorinus Gray, 1850, the penis bears a straight, hollow Page 289 penial stylet. The penis of Emarcusia also bears an acces- sory appendage. In species of Phidiana Gray, 1850, Godiva Macnae, 1954, and all but two species of Herviella Baba, 1949 (BuRN, 1967; RUDMAN, 1980), there is a curved hook at the apex of the penis. Phidiana s.s. contains species with numerous ceratal rows per cluster, rounded foot corners, and the anus situated in the posterior half of the body. Godiva contains species with all cerata arranged in arches, with more than one row of cerata per arch. Herviella con- tains species with oblique rows of cerata that represent the retention of the anterior limb of a ceratal arch (Miller, 1974). Species in this genus also have rounded foot corners. In all these taxa, the penial hook is situated at the end of the efferent duct. The spine curves inwardly, toward the penial apex. In contrast, the penial hook found in Anetarca is subterminal and curves in the opposite direction. On the basis of its unique structure, I hypothesize that the penial hook of Anetarca has evolved independently from other chitinous hooks found in other facelinids. On this basis, Anetarca cannot be readily accommodated into any exist- ing genus and is considered to be distinct from all other described facelinids. ACKNOWLEDGMENTS I am grateful to the individuals who provided specimens to permit the present study to be undertaken: Dave Beh- rens, Gary McDonald, Jim Morin, Cynthia Trowbridge, and Robert Van Syoc. Gary McDonald and Cynthia Trowbridge went to considerable effort to ship live spec- imens to me. Mark Chamberlain also provided color trans- parencies of Noumeaella rubrofasciata. Field work for the collection of material from Baja California was generously provided by the In-House Research Fund and Lindsay Field Research Fund of the California Academy of Sci- ences. I thank Lisa Borok for assistance with the prepa- ration of critical point dried material for scanning electron microscopy. Jan Lundberg printed the final photographic prints and Jean De Mouthe prepared the ink drawings. I greatly appreciate their assistance. LITERATURE CITED Basa, K. 1949. Opisthobranchia of Sagami Bay Collected by His Majesty the Emperor of Japan. Iwanami Shoten: Tokyo. BEHRENS, D. 1980. Pacific Coast Nudibranchs: A Guide to the Opisthobranchs of the Northeastern Pacific. Sea Challeng- ers: Los Osos, California. BEHRENS, D. 1987. Two new aeolid nudibranchs from southern California. 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Bulletin Museum National d Histoire Naturelle Paris, series 2, 9:159-164. ROLLER, R. A. 1972. Three new species of eolid nudibranchs from the west coast of North America. The Veliger 14(4): 416-423. RupDMAN, W. 1978. The dorid opisthobranch genera Halgerda Bergh and Sclerodoris Eliot from the Indo-West Pacific. Zoo- logical Journal of the Linnean Society of London 62(1):59- 88. RupMaAN, W. 1980. Aeolid nudibranch molluscs (Glaucidae) from the Indian Ocean and the south-west Pacific. Zoological Journal of the Linnean Society of London 68(2):139-172. RuDMAN, W. 1981. The anatomy and biology of alcyonarian- feeding aeolid opisthobranch molluscs and their development of symbiosis with zooxanthellae. Zoological Journal of the Linnean Society of London 72(3):219-262. SCHMEKEL, L. 1970. Anatomie der Genitalorgane von Nudi- branchiern (Gastropoda Euthyneura). Pubblicacioni della Stazione Zoologica di Napoli 38(1):120-217. THIELE, J. 1931. Handbuch der Systematischen Weichtier- kunde Band 1. Jena. THompson, T. & G. BRODIE. 1988. Eastern Mediterranean Opisthobranchia: Runcinidae (Runcinacea), with a review of runcinid classification and a description of a new species from Fiji. Journal of Molluscan Studies 54:339-346. WILLAN, R. 1987. Phylogenetic systematics and zoogeography of Australian nudibranchs. 1. Presence of the aeolid Godiva quadricolor (Barnard) in Western Australia. Journal of the Malacological Society of Australia 8:71-85. The Veliger 34(3):291-296 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Morphological Variability in the Gastroesophageal Ganglion of the Nudibranch 77ritonia diomedea by ROGER D. LONGLEY'! Friday Harbor Laboratories, Friday Harbor, Washington 98250, USA Abstract. Gastroesophageal ganglia are occasionally missing from their normal location in the nu- dibranch 77ritonia diomedea. When the identifiable gastroesophageal ganglion neuron G1 is absent from the gastroesophageal ganglion, it is found in the buccal ganglion. The rate of occurrence of this anomaly, which ranged from 3 to 20%, is dependent on animal collection site. Genetic differences and environmental effects are considered as possible reasons for between-site variability in this anomaly. These results suggest that gastroesophageal ganglion neurons may be present in other non-nudibranch opisthobranchs, but because of differences in timing of neuron development and in neuron migration, they develop in the buccal ganglion. INTRODUCTION The gastroesophageal ganglion (geg) is a morphological character that distinguishes nudibranchs from other opis- thobranch mollusks (RUSSELL, 1929). This small ganglion, attached to the lateral margin of the buccal ganglion, is classed by BULLOCK & HORRIDGE (1965) with evolution- arily labile accessory ganglia. The geg typically has a num- ber of small neurons and a giant neuron, G1, with its axon extending in a nerve along the esophagus to the stomach. The neuron G1 has been studied electrophysiologically in Anisodoris nobilis (MacFarland, 1906) by GORMAN & MIROLLI (1969), and a similar neuron has been identified with antibodies in 77ztonia diomedea (Bergh, 1894) and other nudibranchs (LONGLEY & LONGLEY, 1985; MASINOVSKY ef al., 1988). In specimens from the same species, the configuration of the gastroesophageal ganglion and the identifiable neu- ron G1 may vary. In the nudibranch Archidoris pseudoargus (Rapp, 1827), Rose (1971) found that the left gastro- esophageal ganglion and G1 were fused with the left buccal ganglia about 5% of the time. I report here a generally similar anomaly that may occur in either the left or right gastroesophageal ganglion in 77:tonza diomedea. MATERIALS anp METHODS The Pacific coast nudibranch used in this study has been identified as Tritonia diomedea by THOMPSON (1971) and was obtained locally by trawling at three sites in Puget Address for reprints: Pacific Sciences Institute, P.O. Box 835, Friday Harbor, WA 98250, USA. Sound (Figure 1). Tritonia diomedea collected in Belling- ham Bay (KEMPF & WILLows, 1977) apparently feed on Virgularia sp.; however, animals collected in East Sound by WILLows (1967) were found with Stylatula elongata (Gabb, 1863). Tritonia diomedea obtained from Santa Monica Bay, California, were collected in the vicinity of the Hyperion outfall system by Pacific Biomarine Supply Co., Los Angeles, California, and are also typically found with Stylatula elongata (personal communication from Marion Patton). Animal weight ranged from 5 to 400 g. Collection years at each site and numbers of animals used in determining the frequency of G1 in the buccal ganglion are given in Table 1. For East Sound and Bel- lingham Bay sites, several trips were made to each site during a year and a number of trawls were made in the general area of the site each trip. In the latter part of the 1970s when trips to East Sound were generally unsuc- cessful, efforts to restock this site were made by depositing in East Sound egg strings and small animals collected in Bellingham Bay (personal communication from David King, captain of the collection vessel Hyda). Animals from Port Townsend were collected in one trawl, and animals from Santa Monica Bay were received in a single shipment. The location of G1, which was visually identifiable be- cause of its large size and orange pigmentation, was de- termined with a dissecting microscope. In addition, in some preparations one of the following histological procedures was used to identify the location of G1 and to show the number of neurons and neuron size relations in the gas- troesophageal and buccal ganglia. (1) Ganglia were stained in 0.01% methylene blue seawater to enhance visibility of neurons. (2) Nerves were backfilled with cobalt chloride CANADA 10 km Figure 1 Map of northern Puget Sound indicating collection sites: East Sound (1), Port Townsend (2), and Bellingham Bay (3). by placing ganglia in seawater and isolating with a petro- leum jelly dam the freshly cut nerve in 3% CoCl,. After 24 hr at 4°C, these ganglia were washed in seawater, treated with 1% ammonium sulfide solution in seawater to precipitate the CoCl,, fixed in Carnoy’s, dehydrated in ethanol, and cleared and photographed in methy] salicy- late. (3) Buccal and gastroesophageal ganglion paraffin sections were stained using the Feulgen reaction (STOWELL, 1945). RESULTS In Tritonia diomedea the gastroesophageal ganglion (geg), which is attached through a short connective to the an- terolateral edge of each buccal ganglion (Figure 2), is variable in size and may be reduced in cell number or missing entirely from its usual location (Figure 2A, B). The anterior location of this ganglion relative to the buccal ganglion (6g) in 7. diomedea results from the rotated po- sition of the buccal mass such that the buccal ganglia lie on its dorsal surface under the esophagus rather than in a more typical position under the buccal mass. When the geg is attenuated in size or is absent, nerves that normally arise from the geg still branch from its short The Veliger, Vol. 34, No. 3 Table 1 Collection site, year, and number of animals from each site. Number of animals collected at each site Collection site 1977 1978 1981 1988 1989 Bellingham Bay 43 15 — 28 19 Santa Monica Bay 7 — — . 28 — Port Townsend — 37 East Sound 5 2 52 — — connective near the buccal ganglion, but it has not been determined how numbers of axons in these nerves vary with the size of the geg. Cobalt backfills of geg nerves show that some axons in these nerves come from peripheral somata and enter the buccal ganglion or come from somata in the buccal ganglion. In salivary duct nerves, which enter the bg through the geg connective, axons arise from pe- ripheral neurons, enter the buccal ganglion, pass through the buccal commissure, and exit the ganglia through the contralateral homologue of the nerve from which they orig- inated. Other than the identifiable neuron G1 (Figure 2), spe- cific geg neurons with axons in geg nerves have not been identified. The most medial of these nerves, the gastro- esophageal nerve (gen), carries the axon of G1, and in the absence of the geg, this nerve appears to be the principal continuation of the geg connective. Individual neurons smaller than G1, and occasionally a neuron identified as G1 on the basis of its size and pigmentation, may be attached to the gen adjacent to but distal to the geg, 1.e., the geg is not always well-defined. When G1 could not be identified in the geg or on the gen, a neuron similar to G1 in size and pigmentation was found in the buccal ganglion near the axon tract that forms the geg connective (except in 3 of 458 ganglia in which G1 could not be located). In Figure 2B, cobalt backfills of the left and right gas- troesophageal nerves show a typical result when one G1 is in the buccal ganglion and its contralateral homologue is in its normal location in the geg. Following the nomen- clature of MASINOVSKY et al. (1985), the two anterodorsal buccal ganglion neurons of intermediate size that also have axons in the gen and are shown by cobalt backfills of the gen (Figure 2B) are identified as B11 and B12. In the anterior part of the bg, most of the neurons are small with only a few neurons of intermediate size, such that when G1 is anomalously located there, on the dorsal surface or anterior edge of the buccal ganglion, it is easily recognized by its size and pigmentation. This is shown in Figure 2C, where the size of the G1 nucleus can be compared to those of the smaller neurons in the geg and the anterior part of the buccal ganglion near the geg connective. Examples of the gastroesophageal ganglion neuron G1 appearing in the buccal ganglion in 77itonia diomedea were R. D. Longley, 1991 Page 293 ; @ *@e a ° . «e - me gq ' oe, en, s 5 eo. rh a a » .2@ @ ® ® o @ & « s @ * ®e ° Pie) *e” e+ @ 6. e i & 8 P) ” %%— * re 2 P) i Za . @. Figure 2 A. Methylene blue stained buccal and gastroesophageal ganglia showing distribution of neuron sizes and normal location of G1 neurons in the gastroesophageal ganglia. B. Cobalt chloride back- filled gastroesophageal nerves showing G1 in the gastroesopha- geal ganglion (geg) on the left and in the buccal ganglion on the right. Bilaterally symmetric B11 and B12 neurons, which also have axons in the gastroesophageal nerves, are indicated. C. Feul- gen stained nucleus of G1 in the geg and nuclei of smaller neurons in the geg and anterior part of the buccal ganglion (10 um parafhin section). Size bar in B (for both A and B) = 250 um. Size bar in C = 50 um. found in animals from all collection sites. The number of animals from each collection site and the number of anom- alies (G1 in dg) in the left and right ganglia are given in Table 2. Although the frequency appears higher for the left buccal ganglion, the difference between the estimated probability of G1 in the bg on the left (P = 0.157) and on Table 2 Number of G1 neurons found in buccal ganglia (bg) and the probability of G1 occurring in the bg for each collection site. Number of Left bg Right bg Collection site animals anomalies anomalies Probability Bellingham Bay 105 24 17 0.195 Santa Monica Bay 28 6 2 0.143 Port Townsend a7 3 6 0.122 East Sound 59 3 1 0.034 Totals 229 36 26 0.135 the right (P = 0.114) is not significant (z = 1.44, 0.1 > P > 0.05, one-tailed test). In four animals from Bellingham Bay and in one animal from Santa Monica Bay, both gastroesophageal ganglia were missing and the G1 neurons were found in both left and right buccal ganglia, as would occasionally be expected if this anomaly occurred randomly and independently in left and right ganglia. In the absence of a significant left-right bias, data from left and right ganglia are grouped together in comparing the probability of G1 in the dg at different times and from different col- lection sites. For animals collected from Bellingham Bay over a period of years, the estimated probability of G1 in the bg in 1977 (P = 0.22), 1978 (P = 0.20), 1988 (P = 0.18), and 1989 (P = 0.16) does not seem to have changed significantly, although it may be slowly declining. Esti- mated probabilities of G1 in the bg for each collection site are shown in Table 2. When animals from Bellingham Bay, Port Townsend, and Santa Monica Bay are compared using the Chi-squared test, the hypothesis that these prob- abilities are equal cannot be rejected (x? = 2.04, 0.25 > P > 0.1, d.f. = 1). However, the hypothesis of equal probability of this anomaly at different sites is solidly re- jected when East Sound is included as a fourth site (x? = 14.7, P < 0.001, d.f. = 2). DISCUSSION Morphological observations suggest that the neuron iden- tified as G1 in the buccal ganglion (dg) is the same as the G1 neuron normally found in the gastroesophageal gan- glion (geg). G1 in the geg is similar in size and pigmen- tation to its putative counterpart found in the bg. The axon of this neuron in the buccal ganglion follows the same path into the gastroesophageal nerve as G1 in the geg, and the neuron presumed to be G1 is found in the bg only when G1 is absent from the geg. Unlike in Archidoris pseudoargus, where G1 was found predominantly in the left buccal ganglion (RosE, 1971), in Tritonia diomedea there does not appear to be a clear left-right bias for this anomaly. The anatomical differences observed in the 7. diomedea gastroesophageal ganglion are Page 294 not readily described as simply a partial fusion or fusion of this ganglion with the buccal ganglion, as reported for A. pseudoargus by ROsE (1971). In all cases in 7. diomedea when the geg was missing, its nerves did not arise indi- vidually from the buccal ganglion but rather from the geg connective, which was always present; 7.e., the normal site of development of the geg was retained. Smaller neurons that appear to be missing from the geg may develop in the buccal ganglion as G1 apparently does, or alternatively, some or all of these neurons may simply fail to develop. In animals from Bellingham Bay collected in four dif- ferent years over a 13 year period, the variability observed in the development of the geg was consistently high, which suggests that the factors that produced this variability were present throughout this period. Consistent with this result, single samples from the Port Townsend and Santa Monica Bay sites also show high variability of G1 position. Sta- tistically significant data from East Sound showing low variability in the position of G1 are available for only one summer. In the absence of other information, these results might suggest that high variability is normal and that low variability in geg development is the novel condition. How- ever, because the gastroesophageal ganglion has been his- torically described as a normal characteristic of nudi- branchs (BULLOCK & HORRIDGE, 1965; RUSSELL, 1929), animals collected in East Sound, where variability in the geg was low, are considered here to be examples of a more normal development of the nervous system in comparison to animals collected at other sites where geg variability was high. The finding of a significantly lower rate for G1 in the buccal ganglion in animals from East Sound, when com- pared to animals from the other three sites, could be caused by genetic and/or environmental differences. The extent of genetic isolation of veligers settling to metamorphose at the different sites depends on the dispersal of the veligers in the planktonic phase, which lasts at least five weeks in Tritonia diomedea (KEMPF & WILLOWS, 1977). It is likely that animals from Santa Monica Bay, which is exposed to an open-ocean environment, are not genetically isolated from other 7. diomedea along the California coast because of wide dispersal during such a long planktotrophic period (STRATHMANN, 1974), but the long distance between Santa Monica Bay and Puget Sound (2000 km) could produce genetic isolation between animals from these two areas. In Puget Sound the greatest difference in variability in de- velopment of the geg was between animals from the Bel- lingham Bay and East Sound collection sites, which are about 30 km apart (Figure 1). In Bellingham Bay the typical residence time of seawater is 4-5 days with a range of 1-11 days (BECKER et al., 1989), while from a study of sand dollar larvae in East Sound (EMLET, 1986), the res- idence time of larvae in East Sound appears to be less than two weeks. The apparent exchange of external seawater into these sites and the vertical mixing of this seawater by tidal action (WALDICHUK, 1957) as in Rosario Strait, which The Veliger, Vol. 34, No. 3 separates these sites and has tidal currents of 10 km/hr with runs up to 30 km (THOMSON, 1981), suggest that 7. diomedea in the Bellingham Bay and East Sound sites come from a common planktotrophic population of veligers and are not genetically isolated. This does not rule out the possibility of genetic differences in adults from these sites, however, because strong selection by different environ- ments at these sites can result in genetic differences in the animals that mature (SLATKIN, 1985). The low salinity of surface water in Bellingham Bay, which occurs seasonally near the Nooksack River delta, may be an environmental factor that could affect early development of veligers before they settle to metamorphose (if they are present in this surface layer). Studies of de- velopment in the nudibranch veligers of Doridella stein- bergae (BICKELL & CuHIA, 1979), Melibe leonina (BICKELL & KeEempr, 1983), and 77itonia diomedea (KEMPF et al., 1987) have shown that the buccal ganglion, and presum- ably the attached gastroesophageal ganglion, does not ap- pear until the veliger is on the substratum just prior to metamorphosis. This timing suggests that factors affecting the variability in the location of G1 are associated with development while the animals are on or near the sub- stratum rather than while they are in the low-salinity surface water. The absence of low-salinity surface water comparable to that in Bellingham Bay at the Port Town- send and Santa Monica Bay sites, where variability in the position of G1 is also high, suggests that low-salinity sur- face water is not a cause of this variability. Other environmental factors during early development in the veliger phase such as temperature and food would not be different for animals in the East Sound and Bel- lingham Bay sites because of the intermixing of seawater in this area. Veligers in Santa Monica Bay may be exposed to a warmer temperature and develop faster than those in Bellingham Bay, but the variability in the location of G1 is not statistically different at these two sites, which sug- gests that temperature is not an environmental factor that produces this developmental variability. In the laboratory, Tritonia diomedea will feed on a variety of octocorals, but the normal diet of this species is not well documented (WILLows, 1978). The metamorphosing animal will feed on Virgularia sp. (KEMPF & WILLOwS, 1977), which is apparently present in Bellingham Bay, but Stylatula has been reported with 7. diomedea in East Sound and Santa Monica Bay, and in the laboratory 7. diomedea prefers Stylatula elongata over Virgularia sp. (WILLOwS, 1978). Thus, there is no clear correlation with the type of food available to the newly metamorphosed animal and the amount of variability in the development of the geg. Teratogenic substances in bottom sediment may con- tribute to variability in the development of the geg if neu- rons are migrating to this ganglion after the veliger has settled to the substratum. Supporting this possibility is the fact that pollution from industry or municipal wastewater has been reported at each of the three collection sites that R. D. Longley, 1991 Page 295 have high rates of G1 in the buccal ganglion (MPERA, 1971; SCCWRP, 1973; PSEA, 1987). For East Sound in the San Juan Islands, which have no heavy industry and are considered environmentally clean, pollution in bottom sediments is presumed to be relatively low, although no measurements from this area have been reported. This sparsity or absence of data is a ubiquitous problem in trying to assess the effects of pollution at different sites. Dioxins and furans, which have caused fishing bans and consumption advisories at coastal sites around pulp paper mills along Georgia Strait (personal communication from M. Nassichuk, Fisheries and Oceans, Vancouver, B.C.), may also have accumulated from pulp paper mill or mu- nicipal wastewater discharges at the Bellingham Bay, Port Townsend, and Santa Monica Bay sites; however, no mea- surements of these teratogenic chemicals have been re- ported for bottom sediments or biological samples at these sites. Mercury, one teratogenic chemical that has been reported at these sites, has been correlated with abnormal neuron migration (CHO! et al., 1978), has been shown to have teratogenic effects at concentrations lower than those reported in collection site sediments (DIAL, 1978; SCHOWING & BOVERIO, 1979), and has been found to accumulate in the food chain, e.g., in spiny dogfish around the Fraser River delta in Vancouver, British Columbia, (FORRESTER et al., 1972). This correlation of abnormal development of the gastroesophageal ganglion in Tritonia diomedea with the presence of teratogenic chemicals in bottom sediments suggests that such chemicals may act on the developing nervous system and affect the location of G1 and other geg neurons. If this is the case, small changes in the nervous system, such as the anomaly described here, may be a sensitive indicator of environmental pollution. The bilateral symmetry of the geg may provide sufficient redundancy such that only one ganglion is necessary in a viable animal. In five instances, however, T7ritonia diomedea were found with G1 neurons in the buccal ganglia and both gastroesophageal ganglia missing. The fact that 7. diomedea is viable without a geg suggests that the location of neurons in the geg is not a necessary anatomical feature in nudibranchs, but is present in nudibranchs and not in other opisthobranchs because of small developmental tim- ing differences in the central nervous system and differ- ences in neuron migration. Such differences may affect gross morphology of the nervous system and neuron lo- cation without affecting essential characteristics of indi- vidual neurons. This possibility also implies that a neuron functionally similar to G1 may be present in the buccal ganglia of other gastropod species that are closely related to nudibranchs but that do not normally have a gastro- esophageal ganglion. ACKNOWLEDGMENTS I thank A. O. D. Willows, Director of University of Wash- ington Friday Harbor Laboratories, for use of laboratory facilities during most of this work and Peter Getting and Bill Frost for sharing 77ztonza ganglia with me. This work was supported in part by NIH Special Research Fellow- ship 5 FO3 GM45283. LITERATURE CITED BECKER, D. S., R. SONNERUP & J. J. GREENE. 1989. Belling- ham Bay Action Program: Initial Data Summaries and Prob- lem Identification. PTI Environmental Services: Bellevue, Washington. 124 pp. BICKELL, L. R. & F. S. Cua. 1979. Organogenesis and his- togenesis in the planktotrophic veliger of Doridella steinbergae (Opisthobranchia: Nudibranchia). Marine Biology 52:291- 313. BICKELL, L. R. & S.C. Kemper. 1983. Larval and metamorphic morphogenesis in the nudibranch Melibe leonina (Mollusca: Opisthobranchia). Biological Bulletin 165:119-138. Buttock, T. H. & G. A. HorripGe. 1965. Structure and Function in the Nervous System of Invertebrates. W. H. 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Department of Fisheries and Oceans: Ottawa. 291 PP- WALDICHUK, M. 1957. Physical oceanography of the Strait of Georgia, British Columbia. Journal of the Fisheries Re- search Board of Canada 14:321-486. WILLows, A. O. D. 1967. Neural topography and the function of single nerve cells in the behavior of the nudibranch 77- tonia. Doctoral Dissertation, University of Oregon, Eugene. 124 pp. WILLows, A. O. D. 1978. Physiology of feeding in 7ritonza I. Behavior and mechanics. Marine Behavior and Physiology 5:115-135. The Veliger 34(3):297-301 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Female Genital System of Chorus giganteus (Prosobranchia: Muricidae) ROBERTO JARAMILLO Instituto de Embriologia, Universidad Austral de Chile, Casilla 567, Valdivia, Chile Abstract. The female genital system of Chorus giganteus has evolved and specialized in accordance with the requirements of internal fertilization. It includes the renal and pallial oviducts. The pallial oviduct is composed of a glandular region, which is differentiated into albumin and capsule glands, and a nonglandular region formed by the seminal receptacle, the bursa copulatrix, and the genital pore. The epithelium of the seminal receptacle of Chorus giganteus is of the simple glandular type, and many secretion granules are gathered at the surface, suggesting a possible nutritive function. INTRODUCTION The muricids are considered to be some of the most ad- vanced of the prosobranchs. All exhibit internal fertiliza- tion and have complex behavior patterns. A highly spe- cialized reproductive system permits the animal to deposit many eggs within an individual capsule. Many neogastropods do not have a free-living larval stage. In some species with direct development, all the young emerge as miniature adults. In other species, how- ever, many eggs are deposited within each of several cap- sules, but only a few develop; the remainder, termed nu- tritive eggs, serve as a food source for the developing embryos (THORSON, 1935, 1940; RADWIN & CHAMBERLAIN, 1973; Moore & SANDERS, 1978; GALLARDO, 1980). The female genital system of neogastropods has evolved and specialized in accordance with the requirements of internal fertilization and the deposition of eggs within a capsule (FRETTER, 1941, 1946, 1953). The system includes a glandular region for supplying nutritive and capsule- forming materials, the latter being secreted around the eggs after fertilization. The pallial oviduct has been modified for the development of accessory structures such as the seminal receptacle, the bursa copulatrix, and the ingesting gland, in which the autolysis of superfluous sperm takes place. These structures are common throughout the order Neogastropoda, although there are differences between species in their location and the presence or absence of particular structures. The objective of this paper is to de- scribe the reproductive system of the muricid Chorus gi- ganteus, and to compare it with that of some other neo- gastropods. MATERIALS anp METHODS A total of 10 male and 10 female specimens of Chorus giganteus were collected by s.c. at Puerto Claro, Valdivia (39°53'S, 73°22'W). Five male and five female individuals were dissected, and the whole male gonad or the female gonad plus the pallial oviduct was fixed with Hollande Bouin (picric acid-formalin-acetic acid plus copper (II) acetate mixture) for 24 hr. Embedded tissue was sectioned at 5-10 wm and placed serially on slides. Tissue was de- hydrated in a series of increasing ethanol solutions, and sections were stained with azocarmine and hematoxylin- eosin. In addition to the specimens dissected for gonads, mac- roscopic dissections were made of five males and five fe- males under a Leitz Wetzlar stereomicroscope. RESULTS Chorus giganteus is a gonochoristic species that has no apparent external sexual dimorphism. The gonad and vis- ceral mass (Figure 1) are surrounded by the pallial epi- thelium, which is a single layer of cuboidal cells having clear, homogenous cytoplasm and spherical, centrally lo- cated nuclei. Beneath the epithelium lies a thin layer of dense connective tissue containing muscle fibers. This con- nective tissue, which is less densely packed in the deeper part of the gonad, is arranged in irregular segments, and supports the ovarian tubules (Figure 2). The ovary is yellow to dark brown in color, depending on the stage of maturation. It is located in the most distal part of the visceral mass, in the ultimate and penultimate Page 298 The Veliger, Vol. 34, No. 3 5 1 ft fs pie on Ps O8Be, 20-8 R. Jaramillo, 1991 Page 299 (part) whorls of the shell, and lies adjacent to the digestive gland (Figure 1). The ovary is a multilobed organ con- taining large tubules oriented perpendicularly to the spiral axis. The ovarian tubules, some of which intrude between the diverticula of the digestive gland, are separated from one another by a sheet of loose connective tissue projecting perpendicularly from the gonad wall or the mantle. Under this sheet, from which it is separated by the basal lamina, is located the germinal epithelium. Follicle cells and young oocytes lie closest to the basal lamina (Figure 2), whereas vitellogenic and postvitellogenic oocytes occur near the cen- ter of the tubule. The ovarian tubules join to form a single oviduct, which emerges from the ovary and extends along the columellar side of the visceral mass, beneath the pallial epithelium. At the posterior limits of the mantle cavity, the oviduct abruptly enlarges. The enlarged portion continues in the mantle roof. The oviduct consists of two morphologically distinct por- tions, a renal component and a pallial component (Figure 1). The former, which is more proximal to the ovary, passes along the visceral mass before enlarging to form a glan- dular region, the pallial oviduct, which traverses the mantle and terminates near the right tentacle. In gross histological sections, the pallial oviduct is the more visible of the two components, and varies in length from 3 to 6 cm, according to the stage of maturity of the female. The renal oviduct (200-300 wm diameter), which lies embedded in connective tissue under the pallial epithelium, has a wall composed of a thin circular muscle and some connective tissue cells (Figure 4). It is lined with a simple columnar epithelium that lies on a thick basal lamina. These epithelial cells vary in height, giving the cell layer an irregular surface. The pallial oviduct is composed of a glandular region, formed by the more enlarged section, and a nonglandular region (Figure 2). The former is differentiated into two regions, the albumin gland and the capsule gland (Figure 6), both of which are composed of a right and left lobe when viewed in cross section. These lobes are connected by thin walls that give the lumen of the oviduct the ap- pearance of a dorsoventral slit (Figure 6B, C). The albumin gland is the part of the glandular region closest to the ovary (Figure 1), and it is formed by tall Figure 6 Line drawing (not to scale) of a longitudinal section of the pallial oviduct (right side view). A, B, and C show transverse sections. ag, albumin gland; bc, bursa copulatrix; cg, capsule gland; lag, lumen albumin gland; Icg, lumen capsule gland; sr, seminal re- ceptacle; vc, ventral channel. columnar epithelial cells that have a basal cell nucleus. Crypts are produced in the wall of the gland by invagi- nation of the epithelium, and beneath these crypts lies a compact mass of glandular acini that release secretions into the lumen. The capsule gland is more distal to the ovary (Figures 1, 6). Its lumen is lined with small cuneiform cells that overlie clusters of pyriform glandular cells with spherical, basal nuclei. These glandular cells are elongate, and their cytoplasm contains secretory granules that are released into the lumen after migrating through the elongated neck of the cell. These necks are extended toward the surface and the tips reach the lumen, where they are interspersed with cuneiform ciliated cells. The capsule gland stains differentially with hematoxylin and eosin—the lobes appear light red and the connecting walls pale violet-—or with azocarmine—in which these structures stain dark red and pale blue/violet, respectively. The nonglandular region is formed by the seminal re- ceptacle, bursa copulatrix, and the genital pore (Figure 6A-C). Explanation of Figures 1 to 5 Figure 1. Female Chorus giganteus, whole animal, shell removed. DG, digestive gland; F, foot; K, kidney; O, ovary; PO, pallial oviduct; RO, renal oviduct; T, tentacle. Figure 2. Cross section of ovary (x 400) showing the pallial epithelium (E). CT, connective tissue; Oo, oocyte; Y, yolk. Figure 3. Cross section of genital pore (x80). Sz, spermatozoa. Figure 4. Cross section of renal oviduct (x 250). Oo, oocyte; CT, connective tissue; MF, muscle fibers. Figure 5. Cross section (360) of bursa copulatrix (top) and seminal receptacle (bottom) showing spermatozoa. be, bursa copulatrix; CT, connective tissue; GC, glandular cells; sr, seminal receptacle; Sz, spermatozoa. Page 300 Genital pore. The oviduct is connected with the external environment through the genital pore, situated near the right tentacle. This last portion of the oviduct consists of a cylindric, ciliated pseudostratified epithelium, with some intercalated mucous glandular cells. Beneath the epithe- lium lie the basal lamina and a layer of dense connective tissue (Figure 3). Bursa copulatrix. The bursa copulatrix consists of an oval-shaped chamber that is connected with the seminal receptacle and, by means of a short duct, with the glandular portion of the oviduct (Figure 6A). This chamber has a simple cuboidal, ciliated epithelium in which some glan- dular cells contain an eosinophilic secretion. A basal lam- ina and muscle layer are found under this ciliated epi- thelium (Figure 5). The ducts that connect with the oviduct consist of a cylindric, ciliated epithelium. Under the basal lamina is situated a layer of connective tissue with muscle fibers (Figure 5). From the bursa copulatrix emerges a duct, the ventral channel, that runs along the bursa cop- ulatrix and ventral region of the capsule gland. This chan- nel, which is connected always with the lumen of the capsule gland (Figure 6A, B) is covered by a cylindric, ciliated epithelium. Inside the bursa copulatrix and the seminal channel, many spermatozoa can be found. Seminal receptacle. The seminal receptacle is proximal to the bursa copulatrix chamber and is connected to it by a duct similar to that which connects the bursa copulatrix to the capsule gland. The seminal receptacle consists of an elongated chamber divided into two portions: the anterior portion, which is situated over the bursa copulatrix, and the posterior portion situated over the posterior one-third of the capsule gland. This receptacle was full of sperma- tozoa and stained a pale violet color. The wall of the seminal receptacle is covered by a glandular, simple epi- thelium (Figure 5). The cells of this epithelium are pyr- iform with spheric, basal nuclei, and many secretion gran- ules are gathered at the surface of the epithelium. Some spermatozoa were observed scattered over the epithelium with the heads near the granules and the tails toward the lumen of the receptacle (Figure 5). The outer surface of the pallial oviduct is covered by a cylindric epithelium. An ingesting gland was not observed in Chorus giganteus, and no region of the pallial oviduct appears to serve as a sperm ingesting area. DISCUSSION In neogastropods with the habits of depositing numerous eggs within a capsule and of internal fertilization, the female genital system has evolved and specialized in ac- cordance with these behaviors (FRETTER, 1941, 1946, 1953). Fertilization must occur before nutritive and capsule-form- ing materials are secreted around the eggs, and it is most plausible that fertilization occurs in the lumen of the al- bumin gland of this species, because after albumin depo- sition, the fertilization of eggs may be obstructed (KOOL, 1988). However, spermatozoa are generally deposited at The Veliger, Vol. 34, No. 3 the terminal end of the female duct (FRETTER, 1941, 1946; HousToNn, 1976). Spermatozoa may be stored at the ter- minal end, within the bursa copulatrix, or they may be passed up the oviduct and stored within specialized regions connected to the gonoduct, such as the seminal receptacle or the ingesting gland (FRETTER, 1941, 1953; KooL, 1988; OEHLMANN et al., 1988; Houston, 1976). In Chorus gi- ganteus, sperm from a copulation probably are deposited in the bursa copulatrix and then transferred to the seminal receptacle, where they are stored. The seminal receptacle, which occurs generally in neo- gastropods, may be divided, with one portion serving as an ingesting gland and the other to store sperm. Chorus giganteus has a seminal receptacle formed by a simple glandular-type epithelium as in Colus gracilis (HOUSTON, 1976); Concholepas concholepas (HUAQUIN, 1966), another Chilean muricid, also has a seminal receptacle, but Colus stimpsoni (WEST, 1979) and Nucella lapillus (OQEHLMANN, 1988) lack this structure. An ingesting gland or sperm resorbing areas have been reported for some neogastropods. For example, Concho- lepas concholepas (HUAQUIN, 1966), Nucella lapillus (OEHLMANN, 1988), and Plicopurpura patula (KOOL, 1988) have an ingesting gland. In Chorus giganteus an ingesting gland was not observed, nor was any region of the pallial oviduct seen to serve as a sperm ingesting area. The absence of an ingesting gland combined with the presence of a seminal receptacle in Chorus giganteus and Colus gracilis (HousTon, 1976) is in conflict with the suggestions of FRETTER (1941) and HousTon (1976) that these struc- tures may have a common origin and may be homologous. The seminal receptacle usually contains sperm oriented with their heads buried in the epithelium (HyMaNn, 1967). In Chorus giganteus this epithelium is a simple glandular type and many secretion granules are accumulated on the surface of the epithelium. Spermatozoa with their heads buried in these granules may indicate a possible nutritive function of the seminal receptacle. This possibility was suggested for species of Viviparus by ANKEL (1925), who reported the survival of spermatozoa for five months after copulation, and by RAMORINO (1975), who reported that an isolated female of Concholepas concholepas produced fertilized ova four months after copulation. Chorus giganteus has a ventral channel that connects the bursa copulatrix with the proximal portion of the albumin gland. This channel runs along the ventral region of the oviduct, and spermatozoa fertilize eggs at the posterior end of the pallial oviduct before they become surrounded by the secretory products of the albumin gland. Probably not all sperm that pass to the albumin gland are utilized in fertilization (WEST, 1979). In Chorus giganteus, the pres- ence of spermatozoa in the albumin surrounding the eggs was observed, suggesting that excess spermatozoa are void- ed within the egg capsule. A similar description for Colus stumpsoni was reported by WEST (1979). The albumin gland is constituted by columnar epithelial cells. Crypts are produced in the wall of the gland by R. Jaramillo, 1991 invaginations of the epithelium, and beneath these crypts lies a compact mass of glandular acini that release secre- tions into the lumen of the gland. This glandular formation differs from that in the albumin gland of Thais lapillus (FRETTER, 1941) and Colus stimpsoni (WEST, 1979). In- deed, no description similar to the arrangement in Chorus giganteus has been described for any other species. By contrast, the capsule gland of Chorus giganteus appears very similar to that of Thavs lapillus (FRETTER, 1941) and Colus stimpsoni (WEST, 1979). ACKNOWLEDGMENTS I thank Mr. A. Firmani and Mr. J. Deppe for providing the biological material; Dr. R. J. Thompson for his as- sistance in the first manuscript; Mr. J. Pena for his tech- nical assistance in photography; and Miss M. Valenzuela for typing the text. This work was supported by a D.I.D. UACH 1-85-44 Research Project. LITERATURE CITED ANKEL, W. 1925. Zur befruchtunsfrage bei Viviparus viviparus nebst bemerkungen uber die erst reifungsteilung des eies. Senckenbergiana 7:37-54. FRETTER, V. 1941. The genital ducts of some British stenoglos- san prosobranchs. Journal of Marine Biology Association U.K. 25:173-211. FRETTER, V. 1946. The genital ducts of Theodoxus, Lamellaria and 77a, and a discussion on their evolution in the proso- branchs. Journal of Marine Biology Association U.K. 25: 312-351. FRETTER, V. 1953. The transference of sperm from male to female prosobranchs, with reference, also, to the pyrami- dellids. Proceedings of Linnean Society of London 164(1951- 1952):217-224. Page 301 GALLARDO, C. 1980. Adaptaciones reproductivas en gastro- podos muricaceous de Chile; conocimiento actual y perspec- tivas. Investigaciones Marinas de Valparaiso 8(1-2):115- 128. Houston, R. 1976. The structure and function of neogastropod reproductive system, with special reference to Columbella fuscata (Sowerby, 1832). The Veliger 19(1):27-46. Huaquin, L. 1966. Anatomia de Concholepas concholepas (Bru- giére, 1789) (Gastropoda: Muricidae). Tesis de Grado, Es- cuela de Pedagogia Universidad Catolica de Chile. 53 pp.; 24 figs. Hyman, L. 1967. The Invertebrates. Vol. 6. Mollusca I. Mc- Graw-Hill Book Co.: New York. 792 pp. KooL, S. 1988. Aspects of the anatomy of Plicopurpura patula (Prosobranchia: Muricidae: Thaidinae), new combination, with emphasis on the reproductive system. Malacologia 29(2): 373-382. Moore, E. & F. SANDERS. 1978. Spawning and early life of Murex pumun (Gmelin 1791). The Veliger 20(3):251-259. OEHLMANN, VON J., E. STROBEN & P. FIORONI. 1988. Zur anatomie und Histologie des Fortpflanzungssystems von Nu- cella lapillus (L., 1758). (Prosobranchia, Stenoglossa). Zoolo- gischer Anzeiger 221 (3/4):101-116. RADWIN, G. & J. CHAMBERLAIN. 1973. Patterns of larval de- velopment in stenoglossan gastropods. Transactions of the San Diego Society of Natural History 17:107-118. RamorIno, L. 1975. Ciclo reproductivo de Concholepas con- cholepas en la zona de Valparaiso. Revista de Biologia Ma- rina de Valparaiso 15(2):149-177. THORSON, G. 1935. Studies on the egg-capsules and develop- ment of Artic marine prosobranchs. Meddelelser om Gron- land 100(5):1-71. TuHorRSON, G. 1940. Notes on the egg-capsules of some North Atlantic prosobranchs of the genus T7roschelia, Chrisodomus, Volutopsis, Sipho and Trophon. Videnskabelige meddelelser fra Dansk naturhistorisk Forening 104:251-265. WEST, D. 1979. Reproductive biology of Colus stumpsonz. III. (Prosobranchia: Buccinidae). Female genital system. The Veliger 21(4):432-438. The Veliger 34(3):302-308 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 Induced Spawning and Ontogeny of Modiolus capax Conrad (Bivalvia: Mytilidae) by JAVIER ORDUNA ROJAS anp BLANCA CLAUDIA FARFAN Centro de Investigacion Cientifica y de Educacion Superior de Ensenada, Espinoza 843, Ensenada, B.C., Mexico Abstract. The artificial spawning of Modiolus capax was successfully accomplished with the consec- utive application of several stimuli, comprising 6 hr of air exposure, valve scraping, transfer to recir- culating seawater at 27°C, increase in water temperature to 30°C over a 3-hr period, and addition of stripped gametes to the water. Mussels from Bahia de Los Angeles, Baja California, Mexico, subjected to this procedure registered the maximum percentage of spawning in July and August. Described here are the spawning mechanisms, morphology of the sexual products, and the embryonic development of M. capax. Lengths of selected larval stages were as follows: straight-hinge larvae, 108-160 wm; rounded- umbo larvae, 165-195 wm; knobby umbo larvae, larger than 200 wm. Eyespots and a well-developed active foot were first observed in larvae larger than 230 wm. Larval developmental rates at 20 + 1 and 24 + 1°C, hinge structure characteristics, and a three-dimensional growth diagram are included. INTRODUCTION Modiolus capax Conrad, 1837, the fat horse mussel, may be found intertidally, where it forms clusters on rocks or boulders, or dredged in mud to 46 m. Its geographic dis- tribution extends from central California, USA, to Peru, including the Galapagos Islands and the Gulf of California (SMITH & CARLTON, 1975; BRuUscA, 1980; MEINKOTH, 1981). Modiolus capax is not commercially exploited, but its widespread distribution in the eastern tropical Pacific, where the genus Mytilus is not present (KEEN, 1971), has recently stimulated interest in this mussel as a possible candidate for aquaculture or as an indicator of marine pollution. Pollution by heavy metals and chloride hydrocarbons along the west coast of the Gulf of California has already been assessed using natural populations of Modiolus capax (VILLAESCUSA-CELAYA, 1987; GUTIERREZ-GALINDO et al., 1988; EspINOZA-OLGUiN, 1989; Da CosTa-GOMEZ & VALLE- Diaz, 1989). Also in recent years some aspects of its biology related to feeding, metabolism, reproductive cycle, and natural spatfall availability were investigated (OCHOA-BAEZ, 1985; ORDUNA-RojJas, 1986; R1Ico-Mora, 1987; MAZON-SUASTEGUI, 1987; AGUIRRE-HINOJOSA, 1987; ESPINOZA-PERALTA, 1989; GARZA-AGUIRRE & BUc- KLE-RAMIREZ, 1990a, b). The present work describes a reliable procedure for the artificial spawning of M. capax and provides information on its developmental morphology from fertilization to the pediveliger stage and develop- mental rates at two temperatures. MATERIALS anD METHODS Samples of adult Modiolus capax (90 + 11 mm in length) were collected monthly from February through September 1985, from a natural population in Bahia de Los Angeles, Baja California, Mexico (28°53’33’N, 113°31'30”W). The mussels were taken to the laboratory, cleaned of any epi- biotic growth, and kept in lots of 25 in 40-L aquaria with seawater at 36 + 1 %o and 20 + 2°C. Water renewal and feeding were done three times a day to provide an ap- proximate daily ration of Pavlova (Monochrysis) lutheri (Droop) Green equivalent to 0.5% of the mussel’s soft body tissue. The rations were calculated using an average dry weight of 28 pg/cell of P. luther: and 2.5 g of dry soft body tissue/mussel, values estimated in the laboratory with eight nonaxenic P. luther: cultures and 10 mussels. Feeding was discontinued 24 hr before the spawning inducement, which was performed no more than 18 days after collection. A sample of 10 to 15 mussels was used to estimate an J. Ordufia Rojas & B. C. Farfan, 1991 average gonadic index (GI) based on wet weights (+0.001 g) of the gonad central body (GW) and total soft body tissue (TW) according to the formula GI = (GW/TW) x 100. Although from February to April the gonadic index was low (<20%), specimens were used in lots of 25 to test the following spawning stimuli: air exposure, thermal shock, gradual increase in water temperature, potassium chloride immersion, addition of gametes to the water, and me- chanical shock (IWATA, 1951; LOOSANOFF & DAvIS, 1963). Also, different combinations of these stimuli were tested. All the spawning trials lasted 3.5 hr. Fertilization was carried out at 24°C with the spawned products from at least two males and two females. Prior to this, the obtained ova were allowed to hydrate in clean seawater, also at 24°C, from 1 to 2 hr. The addition of 3 mL of a dense sperm suspension to a 4-L suspension of ova was followed by gentle agitation of the mixture, al- lowing 5 min to complete fertilization. The eggs were washed through a 56-ym sieve and transferred to 40-L aquaria containing UV sterilized seawater (36%, 24 + 1°C); their density was adjusted to 150 eggs/mL. At 10- min intervals during the first 3 hr and every hour after- wards, embryonic development was checked under an Olympus BHT dissecting microscope equipped with a camera. Larval culturing at 20 + 1 and 24 + 1°C was also carried out in 40-L aquaria with an initial concentration of 15 larvae/mL. These cultures were supplied with aer- ation and the microalga Pavlova luther in concentrations of 10° cell/mL. Every other day the water was changed, the larvae were examined, photographed and measured, and a sample of organisms preserved in a fixative described by CULLINEY et al. (1975). Values of total length, height, and depth obtained from the preserved larvae were used to construct a three-dimensional growth diagram as de- scribed by CHANLEY & VAN ENGEL (1969). An JSM5300 scanning electron microscope was used to examine the hinge structure of selected larval stages. RESULTS anp DISCUSSION Spawning During the spawning trials, we noted that a combination of air exposure, mechanical stimulation, and thermal stim- ulation invariably elicited in the mussels mucus secretions and a vigorous flow from the exhalant region. Similar behavior in other mussel species is indicative of strong stimulation and usually precedes spawning. Thus, no fur- ther attempts were made with the other stimuli nor to improve or simplify the technique. The successful proce- dure consisted of exposing the specimens to air for 6 hr, scraping their valves, and transferring them to a 70-L rectangular, fiberglass tank with recirculating seawater at 27°C. If a subsequent increase in water temperature to 29°C (accomplished over a 2-hr period) did not initiate spawning, stripped gametes (preferably ova) were added Page 303 to the water and the temperature was increased to 30°C over the course of an hour. Using this procedure, spawning was induced for the first time in early May with a spawning efficiency ratio (organisms spawned/organisms tested) of 5/25. This ratio was 8/25 in June, 18/25 in July, 90/190 in August, and 8/25 in September. The monthly averages in the gonadic index of Modiolus capax were consistent with these results: below 20% from February to April when no spawnings were obtained, highest in July and August (32 + 5%) when the spawning efficiency ratio was maximum, and sharply lower (<15%) in September when the spawning ratio also declined. These results are in fair agreement with the reproductive cycle described by OcHOoA-BAEZ (1985) for a population of M. capax from La Paz, B.C.S., Mexico, a location approximately 750 km south of our collecting site. According to that study, M. capax shows no sexual activity in late autumn and winter, but has contin- uous gonadal activity from spring to early autumn, with a first spawning peak in April and a second, very intense one, in July-August. In this location, the water temper- ature range is 22~29°C; in Bahia de Los Angeles it is 14- 29°C. In both sites the minimum and the maximum tem- perature occur in February and August, respectively. A detailed study of the reproductive cycle of the Modiolus capax population from Bahia de Los Angeles, using his- tological analysis of the gonads, later confirmed this spawn- ing season (GARZA-AGUIRRE & BUCKLE-RAMIREZ, 1990a). However, in contrast to OCHOA-BAEZ (1985) these authors found some gonadal activity during late autumn and win- ter. Later work (still in progress) on the artificial spawning of M. capax has shown that during this period a fraction of the population may spawn, though an additional ther- mal shock may be necessary. The spawning organisms are mainly males, however, while females usually discharge gonadal tissue and a small quantity of ova, which is con- sistent with the reduced gonadal volume found during this period. The spawning mechanisms observed in Modiolus capax were comparable to those described in other mussels (BAYNE, 1978). In neither sex is the deposition of gametes accompanied by valve contractions. The sperm flows out of the valves in a continuous milky stream propelled by currents of the exhalant region. In females the process is similar. The bright orange ova flow out in a scattered stream or in short disconnected bands. The spermatozoa have an oval head (4 x 3 wm) with a small protuberance in the anterior region and two pos- terior spherical bodies less than 1 wm in diameter. The tail is 41-44 um long. The ova are spherical, 70-81 um in diameter, and have no visible nucleus. Embryological Development At 24°C, the egg extrudes the first polar body 3-5 min after fertilization. The second polar body appears under- neath this within 5-10 min of fertilization (Figure 1A). Page 304 The Veliger, Vol. 34, No. 3 Figure 1A-I Embryological development of Modiolus capax. A. Egg with first (1) and second (2) polar bodies. B. Egg prior to first division showing ooplasmic segregation (1) and enlarged perivitelline space (2). C. First division in progress: vegetative pole (1), animal pole (2), and polar lobe (3). D. Second division in progress: macromere (1), micromeres (2), and polar lobe (3). E. Embryo product of third division showing macromere (1) and micromeres (2). F. Morula stage. G. Ciliated gastrula. H. Early trochophore showing cilia (1) and flagellum (2). I. Late trochophore. J. Orduna Rojas & B. C. Farfan, 1991 Page 305 — s 164m 9802997 S.OkU' X2,000 Figure 2A—J Photomicrographs of Modiolus capax larvae and scanning electron micrographs of hinge structures of selected larval stages. A and B. D-shaped larvae, with corresponding lengths of 129 and 156 um. C. Round-umbo stage: 178 um long larva showing velum (1) and incipient foot (2). D and E. Umboned larvae: corresponding lengths of 220 and 250 wm. F and G. Pediveligers showing well-developed, active foot (1), corresponding lengths of 275 and 290 um. H. Hinge structure of newly shelled straight-hinge larva. I. Hinge structure of round-umbo larva. J. Hinge structure of umboned larva. Page 306 240 The Veliger, Vol. 34, No. 3 KEY: =0-| Observations ° =2-5 Observations e =6-I10 Observations @ =||-25 Observations 0 20 40 60 80 100 120 140 160 180 200 320 DEPTH Figure 3 Larval dimensions of Modiolus capax. Three-dimensional diagram showing polyhedron encompassing all possible length-depth-height combinations of M. capax larvae and two-dimensional graphs of height-length and length-depth observations. Figure constructed according to the procedure described by CHANLEY & VAN ENGEL (1969). During the next 20-30 min, ooplasmic segregation toward the center of the egg leaves a conspicuous perivitelline space, and the vitelline membrane becomes wavy in outline (Figure 1B). During the first cleavage, a polar lobe is formed, pro- ducing in this way the trefoil stage shown in Figure 1C. The two-cell stage, reached 50-70 min after fertilization, has unequally sized blastomeres. As shown in Figure 1D, the second cleavage is also unequal and accompanied by polar lobe formation. The four-cell stage has three micro- meres and one macromere, with their nuclei visible as round clear spots in the center of the cells. This stage is reached 80-90 min after fertilization. The following two cleavages occur within the next 50 min. The resulting embryos also show a cup of micromeres over a single macromere (Figure 1E), which becomes enveloped by the micromeral cells as cell multiplication proceeds. The mor- ula (Figure 1F) was first observed 2.5 hr after fertilization and lasted a few minutes. The gastrula stage was observed 7 hr after fertilization (Figure 1G). As in Mytilus edulis (FIELD, 1922) it has short, fine cilia over its entire surface and moves slowly. General descriptions of development in other Modiolus spe- cies are restricted to larval stages and provide no infor- mation regarding their cleavage pattern and early devel- opment (LOoOSANOFF et al., 1966; CHANLEY & ANDREWS, 1971; DE SCHWEINITZ & LUTZ, 1976). Given the type of process described earlier, it seems probable that gastru- lation and germ layer formation are similar to those of Mytilus edulis. In this species, gastrulation is by epiboly and invagination: the mesoderm arises from the macromere that is ultimately surrounded by the micromeral cells, the J. Orduna Rojas & B. C. Farfan, 1991 ectoderm from the micromeres situated on top, and the endoderm from the invagination of micromeres that come to lie in the region of the vegetative pole. Larval Development In the early trochophore of Modiolus capax, observed 9 hr after fertilization, the cilia have grown larger, especially in the anterior region where a long flexible flagellum com- posed of three filaments has also developed (Figure 1H). At this stage, swimming is forward in a spiral motion. During the next 10 hr, the larvae experience a general thickening of the ectoderm and become triangular in shape (Figure 11). A further thickening of the dorsal ectoderm forms the shell gland and the embryonic shell soon appears as a thin integument over the gland. As shell secretion continues, the anterior region of the embryo enlarges to form the velum. A typical straight-hinge larva was observed 24 hr after fertilization. The newly shelled, straight-hinge larvae mea- sure, on average, 105 + 8 wm in length, 85 + 8 um in height, and 53 + 6 wm in depth. The hinge line is 88 + 3 um long; scanning electron micrographs revealed 18 small central hinge teeth and two larger ones on each side (Figure 2H). As in Modiolus modiolus (DE SCHWEINITZ & LUTZ, 1976) and M. demissus (LOOSANOFF et al., 1966) the straight-hinge form in M. capax persists to an approximate length of 160 wm (Figure 2A, B). At this larval size the hinge line is 93 + 3 wm long, and the hinge teeth are stronger and increased by one on each side (Figure 21). The umbo appears as a rounding of the hinge line (Figure 2C), becoming more conspicuous and broadly round in larvae larger than 200 um (Figure 2D-G). With growth the hinge teeth increase further in size and number; the umboned larvae have four large teeth at each end of the hinge line (Figure 2J). In larvae reared at 24 + 1°C, the round-umbo stage was first observed the sixth day of cul- ture and the umbo stage on day 12. Eyespots (on average 8 um in diameter) and a well- developed, active foot were first observed in larvae larger than 230 um in length. In pediveligers of Modiolus capax larger than 270 um (first observed on day 18 of culture at 24°C), the foot, when fully extended, is almost as long as in larvae that are apparently fully competent for settlement (Figure 2G, H). By contrast, in M. modiolus, pigmented eyespots first appear in larvae exceeding 270 um in length, and a full-grown, functional foot appears in larvae larger than 295 wm (DE SCHWEINITZ & LUTZ, 1976). First-shelled larvae transferred from water at 24°C to 20 + 1°C had comparable mortality rates (55%) to those kept at 24°C during the first seven days of culture. At the lower temperature, however, mortality increased sharply thereafter, and larval growth was negligible. Larvae at- tained a maximum length of 150 wm, first registered on the eighteenth day of culture. A data set of 670 length-height measurements from ve- ligers in all stages of development yielded the linear re- Page 307 gression equation: height = 0.913 x length — 14.0 (7? = 0.95). The same calculation for 280 length-depth mea- surements yielded the relationship: depth = 0.978 x length — 57.0 (7? = 0.86). Both sets of data were used to construct the three-dimensional diagram of Figure 3, showing the polyhedrons encompassing all length-height-depth com- binations found throughout larval development. ACKNOWLEDGMENTS We wish to thank Norberto Flores, Luis Manuel Gomez Duran, Gabriel Carrillo, and Carlos Ceballos for their help in the maintenance of the algal and larval cultures, and Saul Serrano and Miguel Avalos for their technical assistance with the scanning electron microscope work. We are grateful to Dr. Domenico Voltolina for his critical reading of the manuscript. Part of the information con- tained in this paper was extracted from the B.S. Thesis of the first author, who acknowledges support from the Con- sejo Nacional de Ciencia y Tecnologia (Co.Na.C. y T.) research studentship program. This work was funded by the Co.Na.C. y T. grant PCECCNA-050018. LITERATURE CITED AGUIRRE-HINoJosA, E. 1987. Analisis de la fijacion, creci- miento y sobrevivencia del mejillon Modiolus capax (Conrad) (Bivalvia-Mytilidae) durante el desarrollo de una comunidad sobre sustratos artificiales en la Bahia de Los Angeles, B.C. M.S. Thesis. Centro de Investigacion Cientifica y de Edu- cacion Superior de Ensenada. Ensenada, B.C., Mexico. 106 pp. [in Spanish]. BAYNE, B. L. 1978. The biology of mussel larvae. pp. 81-120. In: B. L. Bayne (ed.), Marine Mussels: Their Ecology and Physiology. Cambridge University Press: Cambridge, En- gland. Brusca, R. C. 1980. Common Intertidal Invertebrates of the Gulf of California. 2nd ed. The University of Arizona Press: Tucson. 513 pp. CHANLEY, P. & J. D. ANDREWS. 1971. Aids for identification of bivalve larvae of Virginia. Malacologia 11(1):45-119. CHANLEY, P. & W. A. VAN ENGEL. 1969. A three-dimensional representation of measurement data. Veliger 12:78-83. CULLINEY, J. L., P. J. BAYLE & R. D. TURNER. 1975. New approaches and techniques for studying bivalve larvae. Pp. 257-271. In: W. L. Smith & M. H. Chanley (eds.), Culture of Marine Invertebrate Animals. Plenum Press: New York. Da CostTa-GOMEZ BUENO, C. A. & N. A. VALLE-Dfaz. 1989. Disponibilidad biologica de metales traza en el mejillon Mo- diolus capax del Mar de Cortés. B.S. Thesis, Facultad de Ciencias Marinas. Universidad Autonoma de Baja Califor- nia. Ensenada, B.C., Mexico. 77 pp. [in Spanish]. DE SCHWEINITZ, E. M. & R. A. Lutz. 1976. Larval devel- opment of the northern horse mussel Modiolus modiolus (L.) including a comparison with the larvae of Mytilus edulis (L.) as an aid in planktonic identification. Biological Bulletin 150:348-360. EsPINOZA-OLGUIN, G. 1989. Metales traza en moluscos del Valle de Mexicali y Alto Golfo de California. B.S. Thesis, Facultad de Ciencias Marinas. Universidad Autonoma de Baja California. Ensenada, B.C., Mexico. 61 pp. [in Span- ish]. ESPINOZA-PERALTA, A. M. 1989. Dilacion del desove de Mo- Page 308 diolus capax Conrad (Bivalvia: Mytilidae) en condiciones controladas de temperatura y alimentacion. B.S. Thesis, Es- cuela Superior de Ciencias. Universidad Autonoma de Baja California. Ensenada, B.C., Mexico. 106 pp. [in Spanish]. FIELD, I. A. 1922. Biology and economic value of the sea mussel Mytilus edulis. Bulletin of the United States Bureau of Fish- eries 38:127-259. GARZA-AGUIRRE, M. DEL C. & L. F. BUCKLE-RAMIiREZ. 1990a. Ciclo reproductivo del mejillon Modiolus capax (Conrad, 1837) (Bivalvia, Mytilidae, Anisomyaria) en la Bahia de Los An- geles, Baja California. México. Anales del Instituto de Cien- cias del Mar y Limnologia. In press. GARZA-AGUIRRE M. DEL C. & L. F. BUCKLE-RAMIREZ. 1990b. Estructura de tallas, reclutamiento y crecimiento del mejillon Modtolus capax (Conrad) (Bivalvia: Mytilidae) en la Bahia de Los Angeles, Baja California, México. Anales del Insti- tuto de Ciencias del Mar y Limnologia. In press. GUTIERREZ-GALINDO, E. A., G. FLORES-MuNoz & J. A. VILLA- ESCUSA-CELAYA. 1988. Hidrocarburos clorados en molus- cos del Valle de Mexicali y Alto Golfo de California. Ciencias Marinas 14(3):77-90. IwaTA, K. S. 1951. Spawning of Mytilus edulis. 4. Discharge by KCI injection. Bulletin of the Japanese Society of Sci- entific Fisheries 16:393-394. KEEN, A. M. 1971. Sea Shells of Tropical West America Ma- rine Mollusks from Baja California to Peru. Stanford Uni- versity Press: Stanford, California. 1004 pp. LoosanorrF, V. L. & H. C. Davis. 1963. Rearing of bivalve mollusks. /n: F. S. Russell (ed.), Advances in Marine Biology 1:1-136. LoosaANoFF, V. L., H. C. Davis & P. E. CHANLEY. 1966. Di- mensions and shapes of larvae of some marine bivalve mol- lusks. Malacologia 4(2):351-435. The Veliger, Vol. 34, No. 3 MEINKOTH, N. A. 1981. The Audubon Society Field Guide to North American Seashore Creatures. Knopf Editions: New York. 587 pp. MAZON-SUASTEGUI, J. M. 1987. Evaluacion de cinco dietas microalgales en el crecimiento larval de Modiolus capax (Con- rad, 1837) y Pinctada mazatlanica (Hanley, 1845). (Mollus- ca: Bivalvia). M.S. Thesis, Centro Interdisciplinario de Ciencias Marinas. Instituto Politénico Nacional. La Paz, B.C.S., Mexico. 70 pp. [in Spanish]. OcHoA-BAEZ, R. I. 1985. Antecedentes sobre el ciclo de re- produccion de Modiolus capax (Conrad, 1837) (Bivalvia: My- tilidae) en la Bahia de La Paz, Baja California, Sur, México. Investigaciones Marinas CICIMAR (2):86-103. OrbuUNA-Rojas, J. 1986. Desove, desarrollo embriologico y larval del mejillon Modiolus capax (Conrad) (Bivalvia: My- tilidae) en condiciones controladas. B.S. Thesis, Escuela Su- perior de Ciencias Marinas. Universidad Autonoma de Baja California. Ensenada, B.C., Mexico. 52 pp. [in Spanish]. Rico-Mora, R. 1987. Efecto interactivo de la temperatura y de la concentracion de microalgas en la fisiologia alimenticia y la energia potencial para el crecimiento de Modiolus capax (Conrad) (Bivalvia: Mytilidae). M.S. Thesis, Centro de In- vestigacion Cientifica y de Educacion Superior de Ensenada. Ensenada, B.C., Mexico. 91 pp. [in Spanish]. SMITH, R. L. & J. T. CARLTON. 1975. Light’s Manual: In- tertidal Invertebrates of the Central California Coast. 3rd ed. University of California Press: Berkeley. 716 pp. VILLAESCUSA-CELAYA, J. A. 1987. Hidrocarburos clorados en moluscos del Valle de Mexicali y Alto Golfo de California. B.S. Thesis, Facultad de Ciencias Marinas. Universidad Autonoma de Baja California Ensenada, B.C., Mexico. 60 pp. [in Spanish]. The Veliger 34(3):309-313 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 A New Species of Mopalia (Polyplacophora: Mopaliidae) from the Northeast Pacific ROGER N. CLARK'! Field Associate in Malacology, Natural History Museum of Los Angeles County, 900 Exposition Boulevard, Los Angeles, California 90007, USA Abstract. A new species of chiton, Mopalia ferreirai, is described from the shallow subtidal waters (0-18 m) of the Pacific coast of North America. Specimens are of medium size for the genus and resemble Mopalia spectabilis Cowan & Cowan, 1977, but differ in the structure of the girdle hairs. INTRODUCTION For many years an undescribed species of the genus Mo- palia Gray, 1847, has been known to malacologists in the Pacific Northwest. It has often been erroneously identified as Mopalia swanu Carpenter, 1864, M. spectabilis Cowan & Cowan, 1977, or M. lowe: Pilsbry, 1918, to which it is closely related. On recent trips to southeastern Alaska I have collected many specimens of this species. An exam- ination of these along with other specimens from through- out the region (Alaska to central California) confirmed that it was indeed a new species, which is described here. Abbreviations used in text are LACM, Los Angeles County Museum of Natural History; USNM, United States National Museum of Natural History, Washington, DG; CAS, California Academy of Sciences, San Francisco; SBMNH, Santa Barbara Museum of Natural History; ZIAS, Zoological Institute, Academy of Sciences, Lenin- grad; RMNH, Rijksmuseum van Natuurlijke Historie, Leiden; UMMZ, University of Michigan Museum of Zo- ology, Ann Arbor; ANSP, Academy of Natural Sciences, Philadelphia; RNC, private collection of Roger N. Clark; BMNH, British Museum of Natural History, London. TAXONOMY Class POLYPLACOPHORA Gray, 1821 Order NEOLORICATA Bergenhayn, 1955 Family MOPALIIDAE Dall, 1889 ‘Mailing address: 549 Torrey St., Klamath Falls, Oregon 97601, USA. Genus Mopalia Gray, 1847 Type species: Chiton hindsw Reeve, 1847. Mopalia ferreirai Clark, sp. nov. (Figures 1-5, 12, 13) Mopailia lowe, non Pilsbry: BURGHARDT & BURGHARDT, 1969: cover, pl. 4, no. 62, 63; SMITH, 1977:251 (from Sitka, Alaska). Diagnosis: Chitons of medium size (up to 5 cm), variably colored, carinate, beaked: tegmentum microgranular; cen- tral areas reticulate; lateral areas weakly elevated, well defined and finely beaded; mucro posterior one-third. Gir- dle moderately wide (about one-half the width of valve five), armed with short, very spinose setae. Radula mo- palioid, with large tricuspid major laterals. Type material: Holotype (LACM 2329) and 18 para- types (3, LACM 2330); (2, CAS 069315); (1, SBMNH 35141); (2, USNM 860484); (1, ZIAS 1931); (2, UMMZ 252311, 252312); (1, RMNH 9236); (1, ANSP A-13392); and 5 in the collection of the author (RNC 269, 538). Holotype and 11 paratypes are preserved dry (with glycerin), flat, and fully extended; collected 17 August 1986 by R. N. Clark. Seven additional paratypes, also flat and fully extended, are preserved in 70% isopropyl alcohol; collected 28 August 1990. Type locality: Rotary Beach, 5 km S of Ketchikan, Re- villagigedo Island, Alaska (55°16'N, 131°34'W), 0.5 to 1 m, on the bottoms of large rocks. Description: Holotype (Figures 1-4) dry preserved, flat, fully extended; dimensions (including girdle) 41.0 mm in The Veliger, Vol. 34, No. 3 Page 310 Pars s Sex SS x a, * a = rs toe bt ve > af Explanation of Figures 1 to 4 bar = 3 mm. b) i-iv (left side) Figure 3. Intermediate valves ii sp. nov., holotype. > Clark Figure 1. Whole animal (dorsal view), a ferreira 4. Mopalia Figures 1 bar = 4 mm. b) Figure 4. Posterior valve bar = 1 cm. = 5 mm. bar Figure 2. Anterior valve, R. N. Clark, 1991 length, 24.0 mm in width, and 7.0 mm in elevation; jugal angle about 110°; valves carinate, moderately elevated, and slightly beaked. Color overall reddish-brown, with yellow- ish tint on older portion of shell; central portion of anterior valve, and jugum of second valve white. Anterior valve (Figure 2): 11.0 mm in width and bearing 10 rows (2 marginal and 8 intermediate) of low, rounded pustules, about 14 in a series (apex eroded); interstices with 3-8 radiating rows of low, smooth pustules. Intermediate valves (Figure 3): valve five 16.0 mm in width and 8.0 mm in length (including sutural laminae); central areas with 22- 24 longitudinal ribs per side of jugum, transversed by smaller, slightly upwardly diverging ribs giving fine but crisp pitted appearance; lateral areas very slightly raised, defined by one row of pustules similar to those on anterior valve; surface of lateral areas with 8-10 staggered, radi- ating rows of low, smooth pustules; posterior margin of valves with backwards and slightly upwardly directed elongate-oval pustules. Posterior valve (Figure 4): 10.0 mm in width (tegmentum 8.5 mm in width) and 6.0 mm in length (including sutural laminae); mucro posterior one- third and raised; premucronal area with 18 longitudinal ribs crossed by much finer (nearly obsolete) transverse ribs; postmucronal area obsoletely sculptured like lateral areas. Articulamentum translucent white, tinted with faint blue- green at apices. Slit formula typical for genus, 8/1/2, slits in posterior valve separated by a moderately wide caudal sinus; sutural laminae moderately long and rounded; in- sertion teeth long and well formed, and bearing fine vertical striations on outside surface. Girdle (Figure 5): moderately wide, about 4.5 mm at valve five, moderately encroaching at sutures, light brown; covered with very fine spicules up to 150 wm in length, occurring singly or in groups of up to 10, and with tiny scales that are striated along the upper one-fourth; scales on dorsal surface measuring 45 um in length and 8 um in width, those on ventral surface mea- suring 80 wm in length and 12 wm in width; girdle also bearing short (up to 2.0 mm), flattened setae armed with numerous rows of chitinous bristles, generally three rows on dorsal surface and one each on lateral surfaces. Radula (Figure 12): preserved separately, in 70% isopropyl al- cohol, 13 mm in length and bearing about 28 mature rows of teeth; central tooth rectangular, though somewhat ta- pered on the lower one-third, 300 um in length, cutting edge about 150 um in width; minor lateral teeth triangular, about 300 um in length; major laterals very large, about 800 wm in length and bearing one large tricuspid head about 300 um in length and 180 um in width, central cusp the largest, inner cusp slightly smaller, and outer cusp slightly more than one-half length of central one; first marginal teeth large and angular, bearing large hornlike projection on inner lateral margin, dimensions 350 um by 260 um; spatulate (third) marginal teeth large, about 625 um in length and 75 wm in width; outer marginals rounded, diamond shaped, about 430 um in length and 210 wm in width. Gills merobranchial, abanal, extending three-fourths length of foot; about 30 plumes per side. Page 311 5 6 1.0mm 1.Omm 7 8 @G 1.0mm 1.0mm Explanation of Figures 5 to 8 Figure 5. Mopalia ferreirai Clark, sp. nov. (Annette Id., Alaska; RNC 867). Single seta with bristles. Figure 6. Mopalia swanu Carpenter, 1864 (Neah Bay, Wash- ington; RNC 202). Single seta with bristles. Figure 7. Mopalia spectabilis Cowan & Cowan, 1977 (Coos Bay, Oregon; RNC 354). Single seta with bristles. Figure 8. Mopalia acuta (Carpenter, 1855) (Point Conception, California; RNC 444). Single seta with bristles. Variation: Girdle: In some specimens the setae bear a few spines on the ventral as well as the dorsal and lateral surfaces, but this is rare. Coloration: The tegmental coloration may be uniform or nearly uniform rose, violet, light blue, green, yellow, reddish-brown, or orange. Alternatively, it may be mac- ulated with these colors or with black, tan, white, or brown. Some specimens have one or more unicolored valves and the rest varicolored. A common variant has a blue-green ground color maculated with reddish-brown and occasion- ally white. Distribution: Mopalia ferreirai has been found continu- ously between latitudes 60°N (Prince William Sound, Alaska) and 36°N (Carmel Bay, Monterey County, Cal- ifornia) (Figure 13) and from a bathymetric range of +0.5 m in the north to at least 18 m in the southern portion of its geographic range. It is usually found on the bottoms of large rocks. Etymology: Named in honor of the late Dr. Antonio J. Page 312 1.0mm 1.0mm 200ym Explanation of Figures 9 to 12 Figure 9. Mopalia seta Yakovleva, 1952 (Sea of Japan; RNC 482). Single seta with bristles. Figure 10. Mopalia ciliata (Sowerby, 1840) (Point Conception, California; RNC 208). Single seta with bristles. Figure 11. Nopalia lowe: Pilsbry, 1918 (Shell Beach, California; RNC 288). Single seta with bristles. Figure 12. Mopalia ferreirai Clark, sp. nov., holotype. Central and minor lateral teeth. Ferreira, who greatly expanded our knowledge of this fascinating group of mollusks. DISCUSSION Because of the taxonomic confusion associated with the genus Mopalia, it was necessary to examine the type ma- terial (either directly or via photographs) of as many of the similar-appearing species as could be obtained. These were as follows: Mopalia lowe: Pilsbry, 1918 (ANSP 117951), Mopalia spectabilis Cowan & Cowan, 1977 (para- type RNC 223, ex I. McT. Cowan 10593), Chiton acutus Carpenter, 1855 (holotype, BMNH 61.5.20.103; illus- irated by PALMER, 1958:pl. 31, fig. 18). The type of Mopalia swanu Carpenter, 1864, is lost (PALMER, 1958:283), and present identifications of this species are based on BERRY (1951:214-217, 219, pl. 26, fig. 15). The type of Chiton ciliatus Sowerby, 1840, was not examined because the original description (republished by Pilsbry in 1892) is adequate for recognizing this species. The type of Mopalia seta Yakovleva, 1952, is at the ZIAS, The Veliger, Vol. 34, No. 3 Cape Arago Figure 13 Mopalia ferreirai Clark, sp. nov. Distribution map. R. N. Clark, 1991 and was not examined, but Dr. B. I. Sirenko of that in- stitution provided me with four specimens of this species (all collected and identified by him) that agree very well with the original description. On the basis of seta structure, Mopalia ferreirai belongs in the same species group as: M. acuta (Carpenter, 1855), found from central California to Baja California Norte, Mexico; M. swani Carpenter, 1864, found from Unalaska Island, Alaska, to Malibu, California; M. spectabilis Cow- an & Cowan, 1977, found from Kodiak Island, Alaska, to Point Conception, California; and Mopalia seta Yakovleva, 1952, which is restricted to the Sea of Japan. This group is characterized by thick setae (0.5 to >1.0 mm in width at the base in specimens over 25 mm in length) bearing chitinous bristles. This group is clearly distinct from the group—comprised of Mopalia ciliata (Sowerby, 1840), found from Kamchatka to Baja California Norte, Mexico, and M. lowei Pilsbry, 1918, found from Bodega Bay, Califor- nia, to Baja California Norte, Mexico—characterized by thick setae (0.5 to >1.0 mm in width at the base in spec- imens over 25 mm in length) bearing calcareous spines. These two groups were separated by immersing the setae from each species in a solution of hydrochloric acid, which dissolves calcareous spines. This difference in setal com- position is regarded as a provisional indication that the M. acuta and M. ciliata groups are natural assemblages, but this view awaits additional corroboration. Mopalia ferreirai may be distinguished from the other four members of the M. acuta group by the presence of short, flattened (sometimes slightly trough-shaped) setae bearing three rows of short, thick, curved bristles on the dorsal surface and one row each on the lateral surfaces. All other members of the M. acuta have strongly trough- shaped setae. Mopalia acuta (Figure 8) has one row of long, fine, curved bristles originating in the trough; M. swanu (Figure 6) has two rows of long, curved bristles, one each originating on the inner lateral surface of the setae; and M. spectabilis (Figure 7) has very long setae (up to 6.0 mm in length) bearing five rows of very long (up to 1.0 mm), curved bristles. In M. seta the trough is reduced to a narrow groove from which arises a single row of very long, fine, curved bristles. Mopalia ciliata (Figure 10) has flattened or slightly trough-shaped setae that are usually strongly recurved, and bear three rows of short, stout, white spines, not ex- tending beyond one-half the length of the seta. Mopalia lowe: (Figure 11) has long (up to 5.0 mm) thick, tapering, shaftlike (round) setae bearing rather short, sharp spines all the way around the axis, about 6-9 per axil row (in- creasing in number with the size of the seta). Mopalia ferreirai and M. lowe: are superficially similar, particularly in the spinose appearance of their setae. But the tegmental sculpture of M. lowez is much stronger. Also, the spines of M. lowe: (and M. ciliata) are white, whereas the spines of M. ferreirai and all of the members of the M. acuta group are light brown, golden, or tan. Page 313 ACKNOWLEDGMENTS Much thanks and appreciation are due the following peo- ple for their help and encouragement: the late Dr. Antonio J. Ferreira, who started me on this project; Col. George A. Hanselman of San Diego, California, for his excellent photographs and for critical reading of early manuscripts; Rae Baxter of Red Mountain, Alaska, for sending many specimens and data; Dr. lan McTaggart Cowan of Vic- toria, British Columbia, for lending many specimens and providing additional data; Gordon Green of the Royal British Columbia Museum, Victoria, for the loan of spec- imens; Dr. James T. Carlton (formerly of the Oregon Institute of Marine Biology) for making his facilities avail- able to me and for help on the manuscript; Dr. James H. McLean, Los Angeles County Museum of Natural His- tory, for his help and encouragement and for critical read- ing of the manuscript; Thomas C. Rice, of Sea & Shore Museum, Port Gamble, Washington, for his help and encouragement; Lindsey Groves, Los Angeles County Mu- seum of Natural History, for help with the literature search; Dr. Douglas J. Eernisse, University of Michigan Muse- um, for his helpful comments; Dr. B. I. Sirenko of the Zoological Institute, Academy of Sciences, Leningrad, for sending specimens of Mopalia seta; Elizabeth Kools, Cal- ifornia Academy of Sciences, for her help; David S. Wieder of the Academy of Natural Sciences in Philadelphia for sending photographs of the type specimen of M. lowez; Graham and Sue Jeffrey and George P. Holm of Van- couver, British Columbia, and Elsie Marshal and William E. Rice of Seattle, Washington, for making their specimens and collecting notes available to me. The evaluations of two anonymous reviewers greatly enhanced this paper. LITERATURE CITED Berry, S.S. 1951. Notes on some British Columbian chitons— II. Proceedings of the Malacological Society of London 28(6): 213-229. BURGHARDT, G. E. & L. E. BURGHARDT. 1969. A Collector’s Guide to West Coast Chitons. Special Publication Number 4, San Francisco Aquarium Society, Inc. 45 pp., 4 color pls., 7 text figs. (November 1969) (reprinted in Of Sea and Shore, Spring-Winter, 1972). Cowan, G. McT. & I. McT. Cowan. 1977. A new chiton of the genus Mopalia from the north east Pacific coast. Syesis 10:45-52. PALMER, K. E. H. 1958. Type specimens of marine Mollusca described by P. P. Carpenter from the West Coast (San Diego to British Columbia). Geological Society of America, Memoir 76:viii + 376 pp.; 35 pls. SmitH, A. G. 1977. Rectification of west coast chiton nomen- clature (Mollusca: Polyplacophora). The Veliger 19(3):215- 258. YAKOVLEVA, A. M. 1952. Shell-bearing mollusks (Loricata) of the seas of the U.S.S.R. Fauna USSR 45:1-107, figs. 1-53, pls. 1-11 (Zoological Institute, Academy of Sciences, USSR, Moscow and Leningrad) (Translated into English by the Israel Program for Scientific Translations, Jerusalem, 1965.) The Veliger 34(3):314 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 NOTES, INFORMATION & NEWS International Commission on Zoological Nomenclature The following applications were published on 20 Decem- ber 1990 in Volume 47, Part 4 of the Bulletin of Zoological Nomenclature. Comment or advice on these applications is invited for publication in the Bulletin and should be sent to the Executive Secretary, I.C.Z.N., % The Natural His- tory Museum, Cromwell Road, London SW7 5BD, U.K. Case 2768—Lepidomenia Kowalevsky in Brock, 1883 (Mollusca: Solenogastres): proposed designation of Lepidomenia hystrix Marion & Kowalevsky in Fi- scher, 1885, as the type species. Case 2739—Helicarion Férussac, 1831 (Mollusca: Gas- tropoda): proposed conservation, and proposed des- ignation of Helixarion cuviert Ferussac, 1821, as the type species. Case 2588—Haminaea Leach, [1820] (Mollusca: Gas- tropoda): proposed conservation. Case 2670—Kobeltia Seibert, 1873 (Mollusca: Gastropo- da): proposed confirmation of Arion hortensis Férussac, 1819, as the type species. Meeting of the American Society of Zoologists 1991 The 1991 Meeting of the American Society of Zoologists will be held from 27 to 30 December in Atlanta, Georgia. The meetings will be held in conjunction with the Amer- ican Microscopical Society, Animal Behavior Society, ‘The Crustacean Society, and The International Association of Astacology. Many symposia have been planned, includ- ing—Libbie H. Hyman, Life and Contributions; Repro- duction, Larval Development and Recruitment in the Deep- Sea Benthos; Long-term Dynamics of Coral Reefs; and The Biology of Flatworms. The deadline for abstracts is 1 August 1991 if you wish to present a poster or oral paper. For more information contact: Mary Adams-Wiley, Executive Officer American Society of Zoologists 104 Sirius Circle Thousand Oaks, CA 91360 Phone: (805) 492-3585; FAX (805) 492-0370 Announcement: Royal British Columbia Museum During 1991 and 1992, the Royal British Columbia Mu- seum will be packing and moving their biological, anthro- pological, and historical collections to allow for removal of asbestos in their collections building. During this time some of their specimens and artifacts will be inaccessible. They will meet all existing commitments regarding loans and research access and will endeavor to meet any addi- tional requests. Nevertheless, the necessary move will probably inconvenience users of the collection for much of 1991-1992. For information on loans and research, contact: Grant W. Hughes Assistant Director, Collections Program Royal British Columbia Museum 675 Belleville Street Victoria, B.C. Canada V8V 1X4 The Veliger 34(3):315-316 (July 1, 1991) THE VELIGER © CMS, Inc., 1991 BOOKS, PERIODICALS & PAMPHLETS Antillean Seashells The 19th Century Watercolours of Caribbean Molluscs Painted by Hendrik van Rijgersma by HENRY E. Coomans. 1989. De Walburg Pers, P.O. Box 222, 7200 AE Zutphen, Holland. 192 pp., 74 color pls. + 6 text figs. + map endpapers. 814” x 512”. Hard- back. ISBN 906011.616.X. U.S. $24.00. This is not an identification handbook, but it deserves a place in the history of West Indian marine malacology. Van Rijgersma (1835-1877) was a Dutch physician-nat- uralist stationed intermittently from 1863 until his death on the Dutch-French island of St. Martin in the northern Lesser Antilles. He delighted in collecting shells, observing the living animals, and recording some of what he saw with watercolors. (He did the same with flowering plants, the subject of a companion book by H. E. Coomans and M. Coomans-Eustatia.) Van Rijgersma was careful to re- cord whether his observations and paintings were made on St. Martin or on another nearby island that he visited. A few of his illustrations are copies (the radulae), but there are admittedly somewhat amateurish original renditions of the mainly large shells of some of the conchs, cowries, helmets, and cymatiums, etc., that one would expect to find in the West Indies. The color plates illustrate 75 species (excluding the few copied from others). There are surprises such as six turrid species, not usually paid heed by the average collector, and the only good published illustrations known to me of the opercula of Strombus gigas and Cassis madagascariensis (but the last should be brown, not white). Many of the shells are life size, so that four trivias on one plate have come out as small, almost meaningless blobs. But there are nine species showing the living animals—the most unexpected being Strombus gallus. 1 am sure that there is no other color picture of this animal in the literature. Not to be overlooked are the observations in the text, which when originally in Dutch have been translated into English. Van Rijgersma noted the pearls of Strombus gigas. Dr. Henry E. Coomans, a malacologist at the Zoologisch Museum, Amsterdam, has long been interested in Carib- bean malacology and van Rijgersma. In 1974 Coomans published in Bijdragen tot de Tierkunde his doctoral the- sis—a scholarly study of van Rijgersma’s malacological manuscripts and illustrations. At that time, the paintings could only be published in part and in black-and-white. Now we have all of them in splendid color, in a book appropriately written by Coomans himself. The taxonomy is up-to-date (but one could quibble about a few of the names). Morum is correctly placed in the Harpidae. The book is usefully rounded out with a biography of van Rijgersma, a history of malacological research in the Neth- erlands Antilles, and a chapter on Rijgersma and mala- cology, all by Coomans. There is a good bibliography and an index. Van Rijgersma’s manuscripts are now in the Archives of the Academy of Natural Sciences of Philadelphia. Robert Robertson Weichtiere: Europaische Meeres- und Binnenmollusken by ROSINA FECHTER & GERHARD FALKNER, edited by Gunter Steinbach, illustrated by Fritz Wendler. 1990. 288 pp., 740 color photographs, 13 drawings. Steinbachs Na- turftihrer, ISBN 3-570-03414-3. Mosaik Verlag GmbH, Neumarkter Str. 18, D-8000 Munchen 80, Germany. Price: DM 29.80. This German publication, neatly produced in the form of a hard-bound, small-octavo volume, has just appeared in the series of Steinbach’s nature guides (other volumes cover topics ranging from orchids to minerals). The title Weichtiere (mollusks) becomes more narrowly focused in the subtitle, which promises European marine and non- marine mollusks. No, this is not just another pretty-picture-guide for the beginning shell collector. Some technical data: this work presents 660 species, almost half of them documented by color photographs of living animals. A general introduction to Mollusca and its classes is given. In addition to the main groups Gastropoda and Bivalvia, the guide covers eight species of Polyplacophora, five of Cephalopoda, and one of Scaphopoda. Common (German) and Latin names, de- scriptions, chapters on distribution, habits and habitat, and often reproduction are arranged on pages adjacent to the photographs. No page leafing is required to match text and figures. To conserve space in the descriptive part, several abbreviations are used. These are explained on the verso of the title page (p. [4]). The reader not very familiar with the German language may find a translation useful: A = Atlantic Ocean, M = Mediterranean, N = North Sea, O = Baltic Sea, M = Characters, L = Habitat, D = Species occurs in West Germany [original Federal Re- public], (D) = Species was introduced to West Germany, RL = Species is listed in German “red list” of endangered species. The appendix contains a brief system of the treated taxa (arranged by superfamilies), a description of one new taxon (see below), a glossary, suggestions for further read- ing, general hints for collectors, a source index for illus- trations and figured specimens, as well as a comprehensive taxonomic index. Page 316 The general sections, introducing the phylum and class- es, are informative but not always accurate. In cephalo- pods, the molluscan foot does not only form the tentacles (p. 11), but also the funnel. Molluscan gills can show other arrangements than the stated one-, two-, or fourfold con- ditions (p. 11). The sketch of the anatomical organization of a snail (p. 23) should have included a digestive gland. Also, the statement that there are only a few hermaph- roditic bivalves (p. 72) is incorrect. This work is especially noteworthy for its second part, Binnenmollusken (nonmarine [or more literal: landlocked] mollusks), written by Gerhard Falkner (pp. 112-280, in- cluding appendix). This section combines well-researched, concise text with excellent illustrations. The color photo- graphs (480 species of land and freshwater mollusks, 279 of which are illustrated with the living animal) impress the reader by their quality and are also well documented with footnotes stating collecting region and exact scale. In addition to the illustration of taxonomic characters of shells and exposed soft parts, they provide a wealth of biological information. Polymorphism, feeding, mating, egg-laying, aestivation, hibernation, parasitism, and predation are only some of the topics well documented in text and photo- graphs. Space does not allow a list of all the highlights in this part. Whether it is the variation in shell and opercula of freshwater Neritidae (p. 115), the photographs of crawling individuals of Valvatidae (p. 121), Clausiliidae (pp. 154- 165), and land slugs (pp. 184-199), of Oxychilus draper- naudi feeding on an earthworm (p. 180), or the underwater photographs of living unionids (p. 261), even the en- trenched marine worker will be fascinated by this book. Many years of extensive literature and field research must have gone into the preparation of this section. The marine part, written by Rosina Fechter (pp. 9- 111, including the general section), is no match in com- parison and looks like any other shell guide produced for the casual beach tourist. The editor (p. 7) found a some- what peculiar explanation for the difference in quality and arrangement between the marine and nonmarine parts of the book. According to his conception, the beachcomber (Strandganger) needs photographs of empty shells on neu- tral background for identification, while the nonmarine mollusks are best illustrated by photographs of living an- imals because they can be visited in their respective hab- itats. Come on, the North Sea and Mediterranean are not that cold! It is difficult to understand why common species like Gibbula cineraria (p. 31), Littorina littorea (p. 38), and The Veliger, Vol. 34, No. 3 Turritella communis (p. 40) had to be illustrated by beach- worn shells. Unlike Falkner, who collected and photo- graphed especially for this work, Fechter relied largely on photographs supplied by a private collector. The result of this is not only the worn “beached” appearance of many of the shells, but also an array of backgrounds and visible mounting media (from sticky tape on p. 27 to mounting putty on p. 61). The arrangement of the marine gastropod plates is haphazard, negating the original attempt to have text and figures logically and compactly arranged. Shell orientation is random, forcing the reader to rotate the book in various directions. The colored thumb guide, which allows quick location of the nonmarine mollusks at the family level (as German common names), is replaced in the marine section by the not very helpful arrangement at the class level (marine snails, marine bivalves). When com- pared to the excellent nonmarine part, it is odd to discover that readers interested in marine species are not “bur- dened” with minor details such as author and date ref- erences or figure scales. Alfred Limbrunner deserves credit for many of the pho- tographs of living nonmarine animals and all of the non- marine shells. Unfortunately, authors and editor chose a problematic way to show their appreciation. On page 276 (not “275” as stated on p. 158), one finds a description of a new subspecies of Clausiliidae in his honor. In addition to inherent problems of introducing new names in com- mercial book publications, this case is even more compli- cated. The author of this new subspecies is not one of the book authors, but Hartmut Nordsieck, who (according to Steinbach’s introduction) assisted Falkner with the tax- onomy of the volume, especially that of the Clausiliidae. This means that a proper citation for this new taxon must be the cumbersome “Carinigera schuetti limbrunnen H. Nordsieck 7m Fechter & Falkner in Steinbach, 1990.” The exact date of publication cannot be found in the book (the title verso just states “1990”’), and has to be deduced from external sources: the advertisement flyer of the publishing company announced a delivery date of September 1990, the review copy was mailed on 17 October 1990. Despite these points of critique, this book (more pre- cisely, Falkner’s part of this book) is of exceptional quality and sets new standards for a malacological field guide. It is highly recommended for anybody interested in European mollusks. Rudiger Bieler Information for Contributors Manuscripts Manuscripts must be typed on white paper, 82” by 11”, and double-spaced throughout (including references, figure legends, footnotes, and tables). If computer generated copy is to be submitted, margins should be ragged right (7.e., not justified). To facilitate the review process, manuscripts, including figures, should be submitted in triplicate. The first mention in the text of the scientific name of a species should be accompanied by the taxonomic authority, including the year, if possible. Underline scientific names and other words to be printed in italics. Metric and Celsius units are to be used. The sequence of manuscript components should be as follows in most cases: title page, abstract, introduction, materials and methods, results, discussion, acknowledgments, lit- erature cited, figure legends, figures, footnotes, and tables. The title page should be on a separate sheet and should include the title, author’s name, and address. The abstract should describe in the briefest possible way (normally less than 200 words) the scope, main results, and conclusions of the paper. Literature cited References in the text should be given by the name of the author(s) followed by the date of publication: for one author (Smith, 1951), for two authors (Smith & Jones, 1952), and for more than two (Smith e¢ al., 1953). The “literature cited” section must include all (but not additional) references quoted in the text. References should be listed in alphabetical order and typed on sheets separate from the text. Each citation must be complete, with all journal titles unabbreviated, and in the following form: a) Periodicals Cate, J. M. 1962. On the identifications of five Pacific Mitra. The Veliger 4:132-134. b) Books Yonge, C. M. & T. E. Thompson. 1976. Living marine molluscs. Collins: London. 288 pp. c) Composite works Feder, H. M. 1980. Asteroidea: the sea stars. Pp. 117-135. Jn: R. H. Morris, D. P. Abbott & E. C. Haderlie (eds.), Intertidal Invertebrates of California. Stanford Univ. Press: Stanford, Calif. Tables Tables must be numbered and each typed on a separate sheet. Each table should be headed by a brief legend. Figures and plates Figures must be carefully prepared and should be submitted ready for publication. Each should have a short legend, listed on a sheet following the literature cited. Text figures should be in black ink and completely lettered. Keep in mind page format and column size when designing figures. Photographs for half-tone plates must be of good quality. They should be trimmed off squarely, arranged into plates, and mounted on suitable drawing board. Where necessary, a scale should be put on the actual figure. Preferably, photographs should be in the desired final size. It is the author’s responsibility that lettering is legible after final reduction (if any) and that lettering size is appropriate to the figure. Charges will be made for necessary alterations. Processing of manuscripts Upon receipt each manuscript is critically evaluated by at least two referees. Based on these evaluations the editor decides on acceptance or rejection. Acceptable manuscripts are returned to the author for consideration of comments and criticisms, and a finalized manuscript is sent to press. The author will receive from the printer two sets of proofs, which should be corrected carefully for printing errors. At this stage, stylistic changes are no longer appropriate, and changes other than the correction of printing errors will be charged to the author at cost. One set of corrected proofs should be returned to the editor. An order form for the purchase of reprints will accompany proofs. If reprints are desired, they are to be ordered directly from the printer. Send manuscripts, proofs, and correspondence regarding editorial matters to: Dr. David W. Phillips, Editor, 2410 Oakenshield Road, Davis, CA 95616 USA. CONTENTS — Continued Induced spawning and ontogeny of Modiolus capax Conrad (Bivalvia: Mytilidae). JAVIER ORDUNA ROJAS AND BLANCA CLAUDIA FARFAN ...............- 302 A new species of Mopalia (Polyplacophora: Mopaliidae) from the northeast Pacific. ROGER Nu (CLARK «jee ea hs ae Se aie ally erie ee 309 NOTES, INFORMATION & NEWS ISSN 0042-3211 ‘THE VELIGER A Quarterly published by CALIFORNIA MALACOZOOLOGICAL SOCIETY, INC. Berkeley, California R. Stohler, Founding Editor Volume 34 October 1, 1991 Number 4 CONTENTS A bibliography and brief biography of G. Alan Solem, 1931-1990. PEIZABEDH IE OUISEMGIRAR DES ons set Ss ta Ie ac ogy cc eis lea SLi Growth, size at sexual maturity, and egg-per-recruit analysis of the abalone Hathiotis fulgens in Baja California. S. A. SHEPHERD, S. A. GUZMAN DEL PROO, J. TURRUBIATES, J. BELMAR, SNINEIC BAKER AND) P2R2 SEUCZANOWSKI (42555. 2000 006 pn 324 Growth rings within the statolith microstructure of the giant squid Architeuthis. GEORGE D. JACKSON, C. C. LU, AND MALCOLM DUNNING ............. 331 Seasonal variation in biochemical composition of three size classes of the Chilean scallop Argopecten purpuratus Lamarck, 1819. CC HORUAGINIARTINE Zita eon On eR amet Bi) ay acl ehh gen d.10 Pelee ne netle a sicahis 339 The family Galeommatidae (Bivalvia: Leptonacea) in the eastern Atlantic. SYSIRGAD, (CHOIRS se RU Ee etre Laan Ee 344 A new middle Eocene potamidid gastropod from brackish-marine deposits, south- ern California. INICEVARD Blea OWTRIES apt tene erik dn veut oi tags, uke Ws ectilanttabpsaises coat dirs 354 The Philadelphia syntypes of Ammonites hoffmanni Gabb (Cretaceous) (Mol- lusca: Ammonoidea). EGER Wk ODDACANDEMICHABL A] MIURPHY (6 5.008.055 9n 88 e528: | 360 CONTENTS — Continued The Veliger (ISSN 0042-3211) is published quarterly on the first day of Jartee April, July, and October. Rates for Volume 35 are $28.00 for affiliate members (including domestic mailing charges) and $56.00 for libraries and nonmembers (77- cluding domestic mailing charges). For subscriptions sent to Canada and Mexico, add US $4.00; for subscriptions sent to addresses outside of North America, add US $8.00, which includes air-expedited delivery. Further membership and subscription infor- mation appears on the inside cover. The Veliger is published by the California Ma- lacozoological Society, Inc., % Museum of Paleontology, University of California, Berkeley, CA 94720. Second Class postage paid at Berkeley, CA and additional mailing offices. POSTMASTER: Send address changes to The Veliger, Museum of Paleon- tology, University of California, Berkeley, CA 94720. THE VELIGER Scope of the journal The Veliger is open to original papers pertaining to any problem concerned with mol- lusks. This is meant to make facilities available for publication of original articles from a wide field of endeavor. Papers dealing with anatomical, cytological, distributional, eco- logical, histological, morphological, physiological, taxonomic, evolutionary, etc., aspects of marine, freshwater, or terrestrial mollusks from any region will be considered. Short articles containing descriptions of new species or lesser 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 specimen must be included in the manuscript. Type localities must be defined as accurately as possible, with geographical longitudes and latitudes added. Very short papers, generally not exceeding 500 words, will be published in a column entitled “NOTES, INFORMATION & NEWS”; in this column will also appear notices of meetings, as well as news items that are deemed of interest to our subscribers in general. Editor-in-Chief David W. Phillips, 2410 Oakenshield Road, Davis, CA 95616, USA Editorial Board Hans Bertsch, National University, Inglewood, California James T. Carlton, University of Oregon Eugene V. Coan, Research Associate, California Academy of Sciences, San Francisco J. Wyatt Durham, University of California, Berkeley William K. Emerson, American Museum of Natural History, New York Terrence M. Gosliner, California Academy of Sciences, San Francisco Cadet Hand, University of California, Berkeley Carole S. Hickman, University of California, Berkeley David R. Lindberg, University of California, Berkeley James H. McLean, Los Angeles County Museum of Natural History Frank A. Pitelka, University of California, Berkeley Peter U. Rodda, California Academy of Sciences, San Francisco Clyde F. E. Roper, National Museum of Natural History, Washington Barry Roth, Santa Barbara Museum of Natural History Judith Terry Smith, Stanford University Ralph I. Smith, University of California, Berkeley Wayne P. 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The Veliger 34(4):317-323 (October 1, 1991) THE VELIGER © CMS, Inc., 1991 A Bibliography and Brief Biography of G. Alan Solem, 1931-1990 ELIZABETH-LOUISE GIRARDI Division of Invertebrates, Field Museum of Natural History, Roosevelt Road at Lake Shore Drive, Chicago, Illinois 60605, USA G. Alan Solem was born on 21 July 1931, in Chicago, Illinois, the son of a physician and a mother who was active in church work. The family lived in Oak Park, a suburb of Chicago. His association with the Field Museum of Natural History began in 1946, when he began work as a volunteer in the Division of Insects. By 1949, he was working with Dr. Carl P. Schmidt, Chief Curator of Zo- ology, and Dr. Fritz Haas, Curator of the Division of Lower Invertebrates. He attended Haverford College, Haverford, Pennsy]- vania, obtaining his B.S., magna cum laude, in 1952. He did his graduate study at the University of Michigan, Ann Arbor, obtaining his M.A. in 1954 and his Ph.D. in 1956. At Michigan his mentor was Professor Henry Van der Schalie, and he worked during the summers at the Acad- emy of Natural Sciences, Philadelphia, with Dr. Henry Pilsbry, as well as at the Field Museum with Dr. Haas. In 1956 he joined the scientific staff of the Field Museum as the Assistant Curator of Lower Invertebrates, succeed- ing Dr. Haas as Curator in 1959, and becoming Curator of Invertebrates when the name of the Division was changed in 1971. He was still in that position at the time of his death. Beginning in 1971, he was Lecturer for the Committee on Evolutionary Biology at the University of Chicago, where he also taught graduate seminar courses. From 1967 to 1975 he taught both undergraduate and graduate courses at Northwestern University, and directed the research of graduate students at both Chicago and Northwestern. He was appointed a Research Associate in the Department of Biological Sciences at Northwestern in 1970, and at the Australian Museum in 1976. He taught an adult education class in the operation and use of the scanning electron microscope at the Field Museum, 1978-1982. He served as Vice President, President, and Past Pres- ident of the American Malacological Union, as well as a Member or Chairman of many committees of that orga- nization. He was a Counselor, Panel Member, Committee Chairman, or Chairman of four other professional soci- eties, and was on the editorial boards of six scientific pub- lications. He was a Member, Fellow, or Life Member of 10 scholarly scientific societies in four countries, and was named an Honorary Life Member of the Malacological Society of Australia. He participated in 23 international congresses and meet- ings, presenting papers at nearly all of them. At 11 of the meetings, he was a symposium organizer and/or invited speaker. In his 33 years at the Field Museum, he made 19 field trips, many including more than one country. In addition to two trips within the United States, he went once each to Panama, the Lesser Antilles, and Namibia, and three times to New Zealand and various small Pacific islands. However, the bulk of his field work was carried out in Australia, to which he journeyed 11 times. In all, he was out in the field for 40 months: three and a third years, 10% of his time at the Field Museum. I began working for Dr. Solem as a volunteer in 1963, and continued as volunteer, student, and, finally, colleague over the next 27 years. With his encouragement I entered graduate school, and he was one of my teachers, a member of my doctoral committee, and the director of my research. I found him to be a perfectionist, insisting that everyone who worked for him put forth his or her very best, as he always did himself. He was a leader, rather than a driver: he never asked anyone to do anything that he was not willing and able to do himself. If a student was in difhi- culties, he could be patience personified, explaining the problem over and over again—if the student was really trying to understand. If he thought the student was just being lazy, he could be very brusque, and those who at- tempted to get by with second-rate work got very short shrift indeed. Writing of the results of Dr. Solem’s Australian field work, Victoria Huff, former collection manager in the Division of Invertebrates, says in a memo (1990) to Field Museum administration, quoted in a personal communi- cation to me: Page 318 As a result of Dr. Solem’s vigorous research activities and the enthusiam that he generated among field asso- ciates and colleagues in Australia, Field Museum has built an impressive collection of Australian land snails. These collections include over 8,000 lots of land snails, many preserved in alcohol and suitable for further an- atomical studies, virtually all with extremely precise locality data. Associated data include: shell measure- ments of many lots; over 5,500 SEM photographs of shells, jaws, and radulae; hundreds of detailed scientific illustrations of anatomy and shells; well over 300 com- puter-generated distribution maps; and a limited amount of frozen tissue samples, suitable for at least preliminary electrophoretic studies. A colleague, Dr. Rupert L. Wenzel, Curator Emeritus of Insects, has written an excellent summary of Dr. Solem’s work: Solem’s field work and research dealt with molluscs of many parts of the world, but his most important work focused on snails of the Pacific islands and the Australian Region. . .. He became interested in the problem of how numerous closely related species, presumably from a single or only a few colonizations, could evolve on one small island, possibly as a result of conditioning to spe- cific food resources and microniches, leading in turn to microgeographic and reproductive isolation, followed by differentiation into species that differed in their feeding specializations. This ‘flowering’ of species was exemplified by the endodontid snails .. . on the tiny Pacific island of Rapa, and appeared at variance with accepted biogeographic theory on island colonization and establishment of biotic equilibrium. It also conflicted with the then widely ac- cepted doctrine ... that new species did not form in the absence of (macro) geographic isolation. Solem’s concern with these problems led him to pursue detailed analyses of differences in the feeding mechanism of snails, cor- relating them with differences in reproductive anatomy and niche and food specialization. These analyses are essential to delineating their evolutionary relationships and to exploring the history of their distribution through geologic time. ... [He was interested in Australian snails because] it was evident that they represented a largely unknown fauna and seemed to pose questions similar to those encountered in his studies of island faunae. In some ways they proved to be even more interesting because isolated ‘islands’ of vegetation possessed clusters of species that could interact for feeding and reproduction only during the scarce and very short periods of rain. Between rains, they underwent long periods of dormancy. ... Addi- tional field trips ... added much more material and raised additional questions concerning the evolution and relationships of the [Australian] snail fauna to that of the rest of the world. (WENZEL, 1990) The Veliger, Vol. 34, No. 4 Alan Solem was an extraordinarily productive writer. In addition to 45 popular articles and a children’s book, he published 150 scientific papers, including encyclopedia articles, chapters for textbooks, and one semitechnical book. Two more papers were published after his death in 1990, and he left five completed family accounts to appear in Fauna of Australia, as well as 11 other scientific papers in press or submitted. Evaluating Dr. Solem’s productivity, Dr. Wenzel writes: [Solem’s publications] set new high standards for the study and description of molluscs as well as for analysis of the data. ... He described dozens of new genera and several hundred new species and subspecies, a remark- able output, but in itself not as important as the gen- eralizations as well as other research which they make possible. (WENZEL, 1990) As an editor and teacher of scientific writing, he held his students to his own high standards. Multiple rewrites were sometimes required before he was satisfied, but his students understood that he would never allow them to write themselves into indefensible corners. If a paper left the Museum with the Solem zmprimatur, its acceptance for publication was assured. Dr. Solem’s most recent scientific illustrator, Mrs. Lin- nea Lahlum, who worked for and with him for 10 and a half years, spoke at his memorial gathering. A copy of her remarks was given to me, and among them were the fol- lowing: He was straightforward. He did not pretend. ... He was extremely generous and considerate . . . always ready to listen and give what support he could. As busy as he was, he was never too preoccupied to care... . He had a drive for achievement that was unusual. The atmosphere of productive activity that he established was infectious. ... He was demanding, but be made you feel that he had perfect faith in your ability to meet the demand. He had the quality of inspiring excellence. . . . [He was] genuinely appreciative of the work you did [and] never took your work or its quality for granted... . He had his own standard of excellence he was always testing himself against, and he knew that we, too, had our own standards, and must be encouraged to surpass them. ... Working with [him] was never boring. He made it interesting. There was a sense of an adventure in progress. He took such enjoyment in it, such relish of the discovery of the new. [He] once wrote, “The joy of scientific research. Partly answer one question, reveal a dozen others. Learn a bit, question a lot. Improve the quality of the questions asked. A continuous and enjoy- able process on which I’m well along.” (SOLEM, 1981). He was a grantsman extraordinaire. Between 1961 and 1988, he was awarded 15 grants totaling $771,000, with additional funding from private individuals. One of his E.-L. Girardi, 1991 Page 319 grants, from the National Science Foundation, enabled the Field Museum to acquire its first electron microscope. Thanks to his high professional standing and persuasive- ness, at least three major mollusk collections were given to the museum. The Hubricht Collection of eastern North American land snails, comprising 500,000 specimens in 48,000 lots, had been promised to the Museum before Dr. Solem’s death, and arrived shortly thereafter. He had been looking forward eagerly to its coming, because he said it would make the Field Museum’s holdings “the finest land snail collection anywhere.” He died on 26 February 1990, leaving a wife, Sylvia, and two adult children, Anders and Kirsten. He is also survived by his sister, Elizabeth (Mrs. George) Dutton. He is most sorely missed, both personally and profession- ally, by all who knew, or knew of, the man and his work. SCIENTIFIC PUBLICATIONS oF G. ALAN SOLEM Some mollusks from Door Co., Wisconsin. The Nautilus 65(4):127-129. Scalariform Anguispira and Triodopsis. The Nautilus 67(1): 18-20. Marine and fresh-water mollusks of the Solomon Islands. Fieldiana: Zoology 34(22):213-227. Notes on Mexican mollusks. I. Durango, Coahuila and Tamaulipas, with descriptions of two new Humboldtiana. The Nautilus 68(1):3-10, 1 pl. Living species of the pelecypod family Trapeziidae. Pro- ceedings of the Malacological Society of London 31(2): 64-84, 4 figs., 3 pls. Studies on Mesodon ferrissi (Gastropoda, Pulmonata). I. General ecology and biometric analysis. Ecology 36(1): 83-89, 3 figs., 1 table. Mexican mollusks collected for Dr. Bryant Walker in 1926. XI. Drymaeus. Occasional Papers of the Museum of Zoology, University of Michigan, No. 566:1-20, 5 pls. New and little-known Mexican Helicidae (Mollusca, Pul- monata). The Nautilus 69(2):40-44, 2 pls. The helicoid cyclophorid mollusks of Mexico. Proceedings of the Academy of Natural Sciences of Philadelphia 108: 41-59, 2 pls. Non-marine Mollusca from Salobra, Matto Grosso, Bra- zil, and a collection of South Brazilian Artemon. Notulae Naturae of the Academy of Natural Sciences of Philadel- phia, No. 287:1-14, 1 pl. Lysinoe sebastiana Dall, a correction. The Nautilus 69(4): 140. Philippine Zoological Expedition 1946-47. Philippine snails of the family Endodontidae. Fieldiana: Zoology 42(1): 1-12, 4 figs. Notes on some Mexican land snails. Notulae Naturae of the Academy of Natural Sciences of Philadelphia, No. 298: 1-13, 1 pl. Biogeography of the New Hebrides. Nature 181:1253- 1255. Endodontide Landschnecken von Indonesen und Neu Guinea. Archiv ftir Molluskenkunde 87(1-3):19-26, 1 ta- ble. Marine mollusks from Bougainville and Florida, Solomon Islands. Fieldiana: Zoology 39(20):213-226. 1952. 11953! 1953. 1954. 1954. 955% 11955: 1955. 1956. 1956. 1956. IDE/- 1957. 1958. 1958. 1958. 1958. 1958. 1959. 1959. 1959. 1959. 1960. 1960. 1960. 1960. 1960. 1960. 1960. 1961. 1961. 1961. 1961. 1962. 1963. 1963. 1963. 1963. 1963. 1964. 1964. 1964. 1964. 1965. New land snail from Queensland. The Nautilus 72(1): 20-22. Marines from Manus, Admiralty Islands. The Nautilus 72(2):62-64. Marine Mollusca of the New Hebrides. Pacific Science 13:253-268. Notes on Mexican mollusks. II. Occasional Papers of the Museum of Zoology, University of Michigan, No. 611:1- 15, 2 pls. Systematics and zoogeography of the land and fresh-water Mollusca of the New Hebrides. Fieldiana: Zoology 43(1- 2):1-359, 38 figs., 34 pls., 18 tables. On the family position of some Palau, New Guinea, and Queensland land snails. Archiv fiir Molluskenkunde 88(4— 6):151-158, 2 pls. Non-marine mollusks from British Honduras. The Nau- tilus 73(4):129-131, 2 figs. (with F. Haas). Non-marine Mollusca from the Florida Islands, Solomon Islands. Journal of the Malacological Society of Australia 4:39-56, 3 pls. New Caledonian non-marine snails collected by T. D. A. Cockerell in 1928. Notulae Naturae of the Academy of Natural Sciences of Philadelphia, No. 338:1-9, 7 figs. Notes on South American non-marine Mollusca, I-III. Annale del Museo Civico di Storia Naturale di Genova 71:416-432, 2 pls. Review: Handbook of Gastropods in Kansas. The American Midland Naturalist 63:511-512. Fred L. Button collection. The Nautilus 74(1):38-39. Charles G. Nelson collection. The Nautilus 74(1):39. New Caledonian land and freshwater snails. An annotated check list. Fieldiana: Zoology 41(3):413-501, 8 figs. Hydrobiid snails from Lake Ponchartrain, Louisiana. The Nautilus 74(4):157-160. The land snail genus Amphidromus. A synoptic catalogue. Fieldiana: Zoology 41(4):502-677, figs. 15-40 (with F. Laidlaw). A preliminary review of the pomatiasid land snails of Central America. Archiv ftir Molluskenkunde 90(4-6): 191-213, 3 pls., 2 maps. Notes on, and descriptions of, New Hebridean land snails. Bulletin of the British Museum (Natural History), Zo- ology 9(5):217-247, 17 figs., 2 pls. On the identities of Trivza buttoni and Trivia galapagensis Melville, 1900. The Veliger 6(1):20-22, 1 pl. Eudolichotus from British Guiana. Journal of Conchology 25(5):192-194. New Hebridean land mollusks collected by Felix Speiser from 1910-1912. Verhandlungen der Naturforschenden Gesellschaft in Basel 74(2):161-168, 2 figs. Animals, Distribution of. Encyclopaedia Britannica, 1963 ed. 1:967-981. Slug. Encyclopaedia Britannica, 1963 ed. 20:801. Amimopina, an Australian enid land snail. The Veliger 6(3):115-120, 4 figs. Foxidonta, a Solomon Island trochomorphid land snail. The Veliger 6(3):120-123, 5 figs. New records of New Caledonian non-marine mollusks and an analysis of the introduced mollusks. Pacific Science 18(2):130-137. A collection of non-marine mollusks from Sabah (formerly British North Borneo). Sabah Society Journal 2(1-2):1- 40, 5 pls. Adelopoma costaricense Bartsch and Morrison, 1942, not Page 320 1965. 1966. 1966. 1966. 1967. 1968. 1968. 1968. 1968. 1968. 1968. 1969. 1969. 1969. 1969. 1970. 1970. 1970. 1970. 1970. NSIle NOTA. an inhabitant of the United States. The Nautilus 78(2): 68 (with F. Haas). Land snails of the Genus Amphidromus from Thailand (Mollusca: Pulmonata: Camaenidae). Proceedings of the United States National Museum 117(3519):615-628, 2 pls., 2 tables. Zum 80. Geburstag von Fritz Haas. Archiv flr Mollusk- en-kunde 95(1-2):1-2 (with A. Zilch). The neotropical land snail genera Labyrinthus and Isomeria (Pulmonata, Camaenidae). Fieldiana: Zoology 50:1-226, 61 figs., 16 tables. Some non-marine mollusks from Thailand, with notes on classification of the Helicarionidae. Spolia Zoologica Mu- sei Hauniensis, Copenhagen 24:7-110, 24 figs., 3 pls. New molluscan taxa and scientific writings of Fritz Haas. Fieldiana: Zoology 53(2):69-144, 1 pl. Endodontid land snails of Rapa Island: patterns and prob- lems in speciation. Annual Reports for 1967, American Malacological Union, Inc., pp. 33-34. Locomotion in Aporrais and Haliotis. Annual Reports for 1967, American Malacological Union, Inc., p. 45. Basic distribution patterns of non-marine mollusks. Ab- stracts of Papers, Marine Biological Association of India Symposium on Mollusca, p. 25. Cyclospongia discus Miller, 1891—a gastropod operculum, not a sponge. Journal of Paleontology 42(4):1007-1013, 2 figs., 1 pl. (with M. Nitecki). ‘Ptychodon’ misoolensis Adam & van Benthem Jutting, 1939, a New Guinea strobilopsid land snail and a review of the genus Enteroplax. The Veliger 11(1):24-30, 1 fig., 1 table, 1 map. The subantarctic land snail, Notodiscus hookeri (Reeve, 1854) (Pulmonata, Endodontidae). Proceedings of the Malacological Society of London 38(6):251-266, 8 figs., 1 table. Basic distribution of non-marine mollusks. Proceedings of the Symposium on Mollusca, Part I, Marine Biological Association of India, pp. 231-247, 10 figs. Abundance, local variation, and brood pouch formation in Libera fratercula from Rarotonga, Cook Islands. Annual Reports for 1968, American Malacological Union, Inc., pp. 10-12, 3 figs. Methods of subfamily recognition in Pacific Island en- dodontid land snails. Annual Reports for 1969, American Malacological Union, Inc., pp. 37-39, 2 figs. Phylogenetic position of the Succineidae. Jn: Proceedings of the Third European Malacological Congress, Malaco- logia 9(1):289. The endodontoid land snail genera Pilsbrycharopa and Paryphantopsis. The Veliger 12(3):239-264, 3 figs., 6 ta- bles. Malacological application of scanning electron microsco- py. I. Introduction and shell surface features. The Veliger 12(4):394-400, 3 pls., 1 table. The land snail genus Afrodonta (Mollusca: Pulmonata: Endodontidae). Annals of the Natal Museum 20(2):341- 364, 2 figs., 3 tables. Fritz Haas, 1886-1969. The Nautilus 83(4):117-120, portrait. Obituary—Fritz Haas. Journal of Conchology 27(3):182. Mollusks introduced into North America. A Symposium Presented at the 36th Annual Meeting of the American Malacological Union, Key West, Florida, 19 July 1970. Biologist 53(3):89-92. Structure and function of teeth in unrelated carnivorous 1972. 1972. 1972. 1972. 1973. 1973. 1973. LOTS: 1973. 1973. L973: 1973! 1973. 1973. 1974. 1975. 1975. The Veliger, Vol. 34, No. 4 snails. Year Book of the American Philosophical Society, pp. 347-349. Malacological applications of scanning electron micros- copy. II. Radular structure and functioning. The Veliger 14(4):327-336, 1 fig., 6 pls. Mollusks from prehistoric sites in Afghanistan. Trans- actions of the American Philosophical Society 62(4):57- 65. Tekoulina, a new viviparous tornatellinid land snail from Rarotonga, Cook Islands. Proceedings of the Malacolog- ical Society of London 49(2):93-114, 3 figs., 3 pls., 1 table. Microarmature and barriers in the apertures of land snails. The Veliger 15(2):81-87, 5 pls. Convergence in pulmonate radulae. The Veliger 15(3): 165-171, 4 pls. Apertural barriers in Pacific Island land snails of the families Endodontidae and Charopidae. The Veliger 15(4): 300-306, 7 pls. Scanning electron microscope studies of land snail radulae. Bulletin of the American Malacological Union, Inc., March, 1973, p. 43 (abstract). A new genus and two new species of land snails from the Lau Archipelago of Fiji (Mollusca: Pulmonata: Endo- dontidae). The Veliger 16(1):20-30, 6 figs., 3 pls. Craterodiscus McMichael, 1959, a camaenid land snail from Queensland. Journal of the Malacological Society of Australia 2(4):377-385, 1 fig., 1 pl. Review: The Mollusks of the Arid Southwest with an Arizona Checklist, by J. C. Bequaert & W. B. Miller, University of Arizona Press, Tucson, 271 pages, maps. The Nautilus 87(3):78. A problematic organism from the Mazon Creek (Penn- sylvanian) of Illinois. Journal of Paleontology 47(5):903- 907, 2 figs., 2 pls. (with M. Nitecki). Notes on a collection of non-marine Mollusca from Palau Aur, an island off the east coast of Malaya. Federation Museums Journal, 16(1971):91-95 (with P. F. Basch [sic]). Island size and species diversity in Pacific Island land snails. Proceedings of the Fourth European Malacological Congress, Malacologia 14:397-400, 2 tables. Convergent evolution in pulmonate radulae. Proceedings of the Fourth European Malacological Congress, Malaco- logia 14:144-146, 2 figs. On the affinities of Humboldtiana fullingtoni Cheatum, 1972 (Mollusca: Pulmonata: Helminthoglyptidae). The Veliger 16(4):359-365, 2 figs., 2 pls., 1 table. . The Shell Makers: Introducing Mollusks. John Wiley & Sons: New York. 289 p., 12 color pls., many illustrations. . Patterns of radular tooth structure in carnivorous land snails. The Veliger 17(2):81-88, 7 pls., 1 table. . Review: A Field Guide to Shells of the Atlantic and Gulf Coasts and the West Indies, by Percy A. Morris, 3rd ed. W. J. Clench, ed. The Veliger 16(3):341. . Gastropoda. Encyclopaedia Britannica, 15th ed. 1974:947- 954, 3 figs., 1 pl. . Scanning electron microscope and optical microscope ob- servations on urocyclid land snail radulae (Mollusca: Pul- monata: Urocyclidae). Bulletin de I’Institut Royal des Sci- ences Naturelles de Belgique. Biologie 50(7):1-9, 4 pls. (with J. L. Van Goethem). Paleocadmus, a nautiloid cephalopod radula from the Pennsylvanian Francis Creek Shale of Illinois. The Ve- liger 17(3):233-242, 1 fig., 5 pls. (with E. Richardson). Character weighting in land snail classification. Bulletin of the American Malacological Union, Inc., 1974:47-50. E.-L. Girardi, 1991 CY/S). 1975. 1975. 1975. 1975. 975: 1976. 1976. 1976. 1976. 1976. 1976. IST. OTe IST. IT, 1978. 1978. 1978. 1979. 1979. 1979. Notes on Salmon River Valley oreohelicid land snails, with description of Oreohelix waltoni. The Veliger 18(1): 16-30, 7 figs., 5 pls. Polygyriscus virginianus (Burch, 1947), a helicodiscid land snail (Pulmonata: Helicodiscidae). The Nautilus 89(3): 80-86, 3 figs. Structures of recent cephalopod radulae. The Veliger 18(2): 127-133, 4 pls. (with C. F. E. Roper). Recent mollusk collection resources of North America: a report to the Association of Systematics Collections. The Veliger 18(2):222-236. Oreohelicid land snails of the Salmon River Valley, Idaho. Bulletin of the American Malacological Union, Inc., 1975: 55 (abstract). Structures of recent cephalopod raduale. Bulletin of the American Malacological Union, Inc., 1975:58 (abstract). Comments on eastern North American Polygyridae. The Nautilus 90(1):25-36, 29 figs. Species criteria in Anguwispira (Anguispira) (Pulmonata: Discidae). The Nautilus 90(1):15-23, 18 figs. Status of Succinea ovalis chittenangoensis Pilsbry, 1908. The Nautilus 90(3):107-114, 17 figs. Pseudoglessula libera, a new subulinid land snail from Guinea, West Africa (Mollusca: Gastropoda: Pulmonata). Zoologische Mededelingen, Leiden 49(18):255-263, 2 figs., 3 pls. (with A. C. van Bruggen). Apertural microprojection size correlations in pupillid and polygyrid land snails. The Veliger 19(2):115-120, 7 pls. (with S. Lebryk). Endodontoid land snails from Pacific Islands. Part I. Fam- ily Endodontidae. Field Museum Press: Chicago. 501 pp., 208 figs., 114 tables. Radiodiscus hubrichtt Branson, 1975, a synonym of Stria- tura (S.) pugetensis (Dall, 1895) (Mollusca: Pulmonata: Zonitidae). The Nautilus 91(4):146-148, 3 figs. Fossil endodontid land snails from Midway Atoll. Journal of Paleontology 51(5):902-911, 2 figs., 4 pls. Shell microsculpture in Striatura, Punctum, Radiodiscus, and Planogyra (Pulmonata). The Nautilus 91(4):149-155, 18 figs. 1. Fam. Charopidae. Jn: La Faune Terrestre de I’Ile de Sainte-Helene, quatrieme partie, Annales, Sciences Zoolo- giques, Musée Royale de l’Afrique Centrale, No. 220: 521-533, 3 figs., 4 pls., 3 tables. Cretaceous and early Tertiary camaenid land snails from western North America (Mollusca: Pulmonata). Journal of Paleontology 52(3):581-589, 3 figs. Land snails from Mothe, Lakemba, and Karoni Islands, Lau Archipelago, Fiji. Pacific Science 32(1):39-45. Classification of the land Mollusca. Pp. 49-97, 2 figs., 4 tables. In: V. Fretter & J. Peake, (eds.), Pulmonates, Vol. 2A. Academic Press: London and New York. X. A theory of land snail biogeographic patterns through time. Pp. 225-249, 4 figs., 6 tables. Jn: S. van der Spoel, A. C. van Bruggen & J. Lever (eds.), Pathways in Mal- acology, 6th European Malacological Congress, Amster- dam, 1977. Bohn, Scheltema & Holkema: Utrecht; Dr. W. Junk b. v., Publishers: The Hague. North American Paleozoic land snails, with a summary of other Paleozoic non-marine snails. U.S. Geological Sur- vey, Professional Paper No. 1072: 1-42, 6 figs., 10 pls., 4 tables (with E. Yochelson). The phylogeny of clams. [Review: Evolutionary Systematics of the Bivalve Molluscs, Philosophical Transactions of the Royal Society of London.] Science 204:1402-1404. 19/9? 1979. 1979. 1980. 1980. 1980. 1980. 1981. 1981. 1981. 1981. 1981. 1981. 1982. 1982. 1982. 1982. 1982. 1982. 1982. Page 321 Biogeographic significance of land snails, Paleozoic to Re- cent. Pp. 277-287, 4 tables. In: J. Gray & A. J. Boucot (eds.), Historical Biogeography, Plate Tectonics, and the Changing Environment, Proceedings of the 37th Annual Biological Colloquium and Selected Papers. Oregon State University Press: Corvallis. Some mollusks from Afghanistan. Fieldiana: Zoology, New Series 1:1-89, 32 figs., 8 tables. Camaenid land snails from western and central Australia (Mollusca: Pulmonata: Camaenidae). I. Taxa with trans- Australian distributions. Records of the Western Austra- lian Museum, Supplement No. 10:1-142, 35 figs., 11 pls., 10 tables. Faunistics in 1979: a comparative review. [Review: Ha- wauan Marine Shells, by E. A. Kay, vs. New Zealand Mol- lusca, by A. W. B. Powell.] The Veliger 23(1):101-105, 4 tables. The reasons for land snail diversity. Haliotis 10(2)131 (abstract for symposium, 7th International Congress of Malacology, Perpignan, France). Review: The Origin and Evolution of the Gastropod Family Pomatiopsidae, with Emphasis on the Mekong River Tricu- linae, by G. M. Davis. American Scientist 68(2):216. Patterns of speciation in camaenid land snails of the Kim- berley, Western Australia. Journal of the Malacological Society of Australia 4(4):236-237 (abstract for Sympo- sium on Molluscs). Camaenid land snails from western and central Australia (Mollusca: Pulmonata: Camaenidae). II. Taxa from the Kimberley, Amplirhagada Iredale, 1933. Records of the Western Australian Museum, Supplement No. 11:147- 320, figs. 36-73, tables 11-33, pls. 12-14. Camaenid land snails from western and central Australia (Mollusca: Pulmonata: Camaenidae). III. Taxa from the Ningbing Ranges and nearby areas. Records of the West- ern Australian Museum, Supplement No. 11:321-425, figs. 74-110. tables 34-42, pls. 15-18. Land snail biogeography: a true snail’s pace of change. Pp. 197-237, figs. 5.1-5.14. In: G. Nelson & D. E. Rosen (eds.), Vicariance Biogeography: A Critique. Columbia University Press: New York. Standards for malacological collections. Curator 24(1):19- 28 (with W. K. Emerson, B. Roth & F. G. Thompson). Small land snails from northern Australia. I. Species of Gyliotrachela Tomlin, 1930 (Mollusca: Pulmonata: Ver- tiginidae). Journal of the Malacological Society of Aus- tralia 5(1-2):87-100, 19 figs. Sympatric species diversity of New Zealand land snails. New Zealand Journal of Zoology 8:453-485, 2 figs., 6 tables, appendices (with F. M. Climo & D. J. Roscoe). The tyranny and opportunity of numbers. ASC Newsletter 10:1-5 (with W. Burger). Why New Zealand forests have so many land snail species. American Philosophical Society, Year Book for 1981: 46- 47. Pulmonata. McGraw-Hill Encyclopedia of Science and Technology, 5/e:88-89. Basommatophora. McGraw-Hill Encyclopedia of Science and Technology, 5/e:138-139. Stylommatophora. McGraw-Hill Encyclopedia of Science and Technology, 5/e:255-256. Systellommatophora. McGraw-Hill Encyclopedia of Sci- ence and Technology, 5/e:463. Small land snails from northern Australia. II. Species of Westracystis Iredale, 1939 (Mollusca: Pulmonata: Heli- Page 322 1982. 1983. 1983. 1983. 1984. 1984. 1984. 1984. 1984. 1984. 1984. 1985. 1985. 1985. 1986. 1986. 1988. carionidae). Journal of the Malacological Society of Aus- tralia 5(3-5):175-193, 19 figs. Austroassiminea letha, gen. nov., sp. nov., a rare and en- dangered prosobranch snail from south-western Australia (Mollusca: Prosobranchia: Assimineidae). Journal of the Royal Society of Western Australia 65(4):119-129, 13 figs., 2 tables (with E. L. Girardi, S. Slack-Smith & G. M. Kendrick). Endodontoid land snails from Pacific Islands (Mollusca: Pulmonata: Sigmurethra). Part II. Families Punctidae and Charopidae, zoogeography. Field Museum Press: Chi- cago. 336 pp., 143 figs., 76 tables. First record of Amphidromus from Australia, with ana- tomical notes on several species (Mollusca: Pulmonata: Camaenidae). Records of the Australian Museum 35:153- 166, 24 figs. Lost or kept internal whorls: ordinal differences in land snails. Journal of Molluscan Studies, Supplement 12A: 172-178, 5 text figs. Small land snails from northern Australia. IIT. Species of Helicodiscidae and Charopidae. Journal of the Malaco- logical Society of Australia 6(3-4):155-179, 45 figs. Camaenid land snails from western and central Australia (Mollusca: Pulmonata: Camaenidae). IV. Taxa from the Kimberley, Westraltrachia Iredale, 1933 and related gen- era. Records of the Western Australian Museum, Sup- plement No. 17:427-705, figs. 111-180, pls. 19-63, tables 43-75. Camaenid land snail reproductive, cycle and growth pat- terns in semi-arid areas of north-western Australia. Aus- tralian Journal of Zoology 32(4):471-491, 2 figs., 5 tables (with C. C. Christensen). Pseudo-operculate pulmonate land snails from New Cal- edonia. The Veliger 27(2):193-199, 5 figs. (with S. Tillier & P. B. Mordan). Preface. Pp. vii-ix. In: A. Solem & A. C. van Bruggen (eds.), World-wide Snails: Biogeographical Studies on Non- marine Mollusca. E. J. Brill: Leiden (with A. C. van Bruggen). Introduction. Pp. 1-5. Jn: A. Solem & A. C. van Bruggen (eds.), World-wide Snails: Biogeographical Studies on Non- marine Mollusca. E. J. Brill: Leiden. A world model of land snail diversity and abundance. Pp. 6-22, 2 tables. In: A. Solem & A. C. van Bruggen (eds.), World-wide Snails: Biogeographical Studies on Non-ma- rine Mollusca. E. J. Brill: Leiden. Simultaneous character convergence and divergence in Western Australian land snails. Biological Journal of the Linnean Society of London 24:143-163, 8 figs., 3 tables. Structure and habitat correlations of sympatric New Zea- land land snail species. Malacologia 26(1-2):1-30, 9 figs. (with F. M. Climo). Camaenid land snails from western and central Australia (Mollusca: Pulmonata: Camaenidae). V. Remaining Kim- berley genera and addenda to the Kimberley. Records of the Western Australian Museum, Supplement No. 20: 707-981, figs. 181-256, tables 76-94, pls. 64-94. Origin and diversification of pulmonate land snails. Jn: E. R. Trueman (ed.), The Mollusca, Vol. 10:269-293. Ac- ademic Press: London. Pupilloid land snails from the south and mid-west coasts of Australia. Journal of the Malacological Society of Aus- tralia 7(3-4):95-124, 36 text figs. New camaenid land snails from the northeast Kimberley, Western Australia. Journal of the Malacological Society of Australia 9:27-58, 3 tables, 34 text figs., 3 pls. 1988. 1989. 1989. 1990. 1990. 19.5972 1957. 1958. 1958. 1958. 1958. 1958. 1959. 1959. 1959. 1960. 1960. 1960. 1960. 1961. 1961. 1961. 1962. 1963. 1963. The Veliger, Vol. 34, No. 4 Maximum in the minimum: biogeography of land snails from the Ningbing Ranges and Jeremiah Hills, northeast Kimberley, Western Australia. Journal of the Malaco- logical Society of Australia 9:59-113, 10 tables, 25 text figs. Non-camaenid land snails of the Kimberley and Northern Territory, Australia. I. Systematics, affinities, and ranges. Invertebrate Taxonomy 2(4):455-604, text figs. 1-217, tables 1-2. Cristilabrum kessneri, a new camaenid land snail from the Jeremiah Hills, Western Australia. Journal of the Mal- acological Society of Australia 10:97-107, 2 tables, 5 text figs., 2 pls. Allozyme variation in the Australian camaenid land snail Cristilabrum primum: a prolegomenon for a molecular phy- logeny of an extraordinary radiation in an isolated habitat. The Veliger 33(2):129-139, 4 figs., 5 tables (with D. Woodruff). How many Hawaiian land snail species are left?—and what can we do for them? Bishop Museum Occasional Papers 30:27-40. POPULAR ARTICLES Unusual Pacific shells added to museum collections. Chi- cago Natural History Museum Bulletin 28(4):3, 7. Museum receives valuable shell collection. Chicago Nat- ural History Museum Bulletin 28(10):5. Museum acquires Zetek shell collection. Chicago Natural History Museum Bulletin 29(1):4. Science baffler: how many animals are there? Chicago Natural History Museum Bulletin 29(2):5-7. Hunger & thirst: man & snails. Chicago Natural History Museum Bulletin 29(6):7. Edgar Allen Poe, ghost writer. Chicago Natural History Museum Bulletin 29(10):4. Shell exhibit features little-known inhabitants. Chicago Natural History Museum Bulletin 29(12):3. Museum collectors, adventures in Panama. Chicago Nat- ural History Museum Bulletin 30(6):5. Museum acquires museum. Chicago Natural History Museum Bulletin 30(8):2 (with E. Richardson). Review: Sea Treasure, A Guide to Shell Collecting, by Kath- leen Yerger Johnstone. Chicago Natural History Museum Bulletin 30(8):7. Some specimen labels tell old stories. Chicago Natural History Museum Bulletin 31(2):7. Museum receives gift of lifelong hobby! Chicago Natural History Museum Bulletin 31(3):8. Rocks, snails, and cactus spines. Chicago Natural History Museum Bulletin 31(6):3, 8. Hidden relics of the ocean deeps. Chicago Natural History Museum Bulletin 31(10):6-7. Wanted: used snail shells. Chicago Natural History Mu- seum Bulletin 32(4):3. Gems of the Everglades. Chicago Natural History Mu- seum Bulletin 32(5):8-9. Articles on invertebrates. Basic Science Handbook, K-3, by W. L. Beauchamp & H. J. Challand. Scott, Foresman, & Co. Portrait of a collector. Chicago Natural History Museum Bulletin 33(6):6-7. Pacific snail trail. Chicago Natural History Museum Bul- letin 34(4):4-5, 7. Pacific snail trail. Chicago Natural History Museum Bul- letin 34(5):6-7. E.-L. Girardi, 1991 1963. 1964. 1965. 1965. 1966. 1967. 1967. 1969. 1970. 1970. 1970. 1970. 1971. 1972. 1973. 1976. 1977. 1977. 1979. 1979. Life Along the Seashore. Encyclopedia Britannica Press. 30 pp. (children’s book). Giant hunters of the open sea. Chicago Natural History Museum Bulletin 35(6):2-3. Snails and human welfare. Part I. Health 10(7):31-37. Snails and human welfare. Part II. Health 10(8):17-23. Sacks of exotic dirt. Field Museum of Natural History Bulletin 37(6):3-4. Review: Shell Collecting: An Illustrated History, by S. Peter Dance. Field Museum of Natural History Bulletin 38(9):7. The two careers of Fritz Haas. Field Museum of Natural History Bulletin 38(11):2-5. ... in his dim, uncertain sight. Field Museum of Natural History Bulletin 40(3):7-9. Fritz Haas, former curator, dies. Field Museum of Nat- ural History Bulletin 41(2):12. Extinction strikes 10,000 species, Man remains uncon- cerned. Field Museum of Natural History Bulletin 41 (4): 4-6. Another view of the elephant. Field Museum of Natural History Bulletin 41(12):8-10. Wiped out and unsung. National Parks and Conservation Magazine 44(275):7-8. High hopes to fallen dreams. Field Museum of Natural History Bulletin 42(5):11-13. The world is our study. Field Museum of Natural History Bulletin 43(7):13-16. Below man’s vision: electronic windows to unseen worlds. Field Museum of Natural History Bulletin 44(2):2-7. Western Australian field program, 1976-77. Field Mu- seum of Natural History Bulletin 47(7):8-9. Kimberley snail hunt—Round I. Field Museum of Nat- ural History Bulletin 48(3):6-9. Kimberley snail hunt—Round II through IV. Field Mu- seum of Natural History Bulletin 48(9):6-9. Chance encounter of a good kind. Field Museum of Nat- ural History Bulletin 50(1):10-13. Kimberley snail hunt—Round V. Field Museum of Nat- ural History Bulletin 50(4):4-7. Page 323 1981. A curatorial legacy: 226 years dedication to Field Mu- seum. Field Museum of Natural History Bulletin 52(1): 6-14. 1981. Kimberley snail hunt again! Field Museum of Natural History Bulletin 52(3):18-23. 1985. Founders’ Council member honored. Field Museum of Natural History Bulletin 56(8):25-26. 1986. A collector’s tale. Field Museum of Natural History Bul- letin 57(6):22-25. 1987. Afterword A, the Streets and their expeditions. Field Mu- seum of Natural History Bulletin 58(1):23-24. 1988. We gottah, wannah, gointuh, should, must, will. . .see. Field Museum of Natural History Bulletin 59(5):24-29 (with W. P. Fawcett). Note: At the time of Dr. Solem’s death, six of his scientific papers were in press, 11 had been submitted for publi- cation, and one was in review. The paper in review and one of those in press were published after his death, and appear above (1990). When all of the remaining papers have been published, an addendum to this bibliography will appear. A list of his new molluscan taxa will also appear at a later date. ACKNOWLEDGMENTS The author wishes to thank Victoria Huff and Margaret Baker for their assistance in the preparation of this paper, and Mrs. Huff, Mrs. Lahlum, and Dr. Wenzel for per- mission to quote them. LITERATURE CITED SOLEM, A. 1981. Kimberley snail hunt, again! Field Museum of Natural History Bulletin 52(3):18-23. WENZEL, R. L. 1990. G. Alan Solem, 1931-1990. Field Mu- seum of Natural History Bulletin 61(3):8-9. The Veliger 34(4):324-330 (October 1, 1991) THE VELIGER © CMS, Inc., 1991 Growth, Size at Sexual Maturity, and Egg-Per-Recruit Analysis of the Abalone Haliotis fulgens in Baja California by S. A. SHEPHERD Department of Fisheries, 135 Pirie Street, Adelaide, South Australia 5000 S. A. GUZMAN DEL PROO Escuela Nacional de Ciencias Biologicas I.P.N. Apdo 26375, Mexico DF 02860 J. TURRUBIATES Centro Acuacultural e Investigacion Pesquera (I.N.P.), Bahia Tortugas, B.C.S. C.P.23950 Mexico J. BELMAR Escuela Nacional de Ciencias Biologicas I.P.N. Apdo 26375, Mexico DF 02860 JANINE L. BAKER anp P. R. SEUCZANOWSKI Department of Fisheries, 135 Pirie Street, Adelaide, South Australia 5000 Abstract. The growth rate and size at sexual maturity of Haliotis fulgens were measured at Bahia Tortugas, Baja California Sur. The parameters of the fitted von Bertalanffy growth equation were: K = 0.38, L., = 183 mm. There was no significant difference in growth rate between the sexes. The length at which 50% of a sample reached sexual maturity was 105 mm. These data, with other published data on H. fulgens, were used to do yield-per-recruit and egg-per-recruit analyses. Maximum yields occurred at ages 4-7 years, according to the natural mortality rate chosen. At the current fishery size limit (145 mm), egg production levels are 6-17% and are considered to be dangerously low and inadequate to maintain recruitment. INTRODUCTION Numerous abalone fisheries around the world have col- lapsed with increasing fishing pressure, and in some cases this has been attributed to the removal of too much of the parent stock (recruitment overfishing) (reviewed by BREEN, in press). In consequence, simple egg-per-recruit models have been devised to show the number of eggs produced under different fishing intensities and with different size limits (SLUCZANOWSKI, 1984, 1986; BREEN, in press; TEGNER et al., 1989). Such models can be used in a pop- ulation at equilibrium to specify size limits to maintain a given level of egg production or, alternatively, to examine a fishery in retrospect to see what egg production level maintained the stock or, in the case of a collapsed fishery, led to such a collapse. In the absence of knowledge of the relation between breeding stock size and recruitment, egg- per-recruit analyses of many stocks, including collapsed ones, can give clues as to appropriate egg production levels. The abalone Haliotis fulgens Philippi is taken commer- cially in Baja California where it comprises up to 85% of the abalone catch (TURRUBIATES et al., 1987), but little is known of the parameters required to apply an egg-per- recruit model to the fishery. In this paper we describe an S. A. Shepherd e¢ al., 1991 BAHIA TORTUGAS Los Morros CaS Si Page 325 Figure 1 Map of Bahia Tortugas showing Los Morros Islands, and (on right) their location in Baja California. experiment to measure the growth rate of H. fulgens at Bahia Tortugas, Baja California (Figure 1). We also at- tempted to measure the natural mortality rate, M, but the experiment failed, and we discuss it only to illustrate the problems of dealing with a cryptic species. We determined size at sexual maturity, and used these results and other published information to do yield and egg-per-recruit anal- yses for H. fulgens. We then apply the results to manage- ment of the fishery and suggest an appropriate size limit. MATERIALS anD METHODS By agreement with the local fishermen’s cooperative, a study site on the inner shore of Los Morros Island was selected and closed to fishing. The shore here is composed of large boulders and blocks up to 2 m diameter close to shore and a deeply creviced reef of 1-2 m relief. The giant kelp, Macrocystis pyrifera, forms a dense forest to about 2 m depth and, beyond the forest, the seagrass Phyllospadix torreyi, coralline algae, and other red and brown algae dominate exposed rock surfaces to about 5 m depth where rock is buried by sand. Haliotis fulgens mainly occurred at the edge of the Macrocystis forest from 2 to 4 m depth. Individuals of Haliotis fulgens between 70 and 140 mm shell length (SL) were measured and marked with plastic numbered tags riveted to the shell through the proximal pore-hole (PRINCE, 1991) in August 1987, November 1987, and May 1988, and placed within an area marked out with chain. In August 1988, one year after the initial tagging, the area was thoroughly searched for 35 hr diving time and marked individuals recaptured. Subsequent fur- ther searching for 9 hr increased the number of recaptures. The abalone taken in August 1987 were sexed, by visual inspection of the gonad, prior to marking, and the data obtained were used to determine size at sexual maturity. In this species the gametes are mature from June to Sep- tember and the sexes are readily distinguishable visually by color (GUZMAN DEL PROO, in press); visual inspection is considered to give a reliable indication of the presence of gametes, but not the onset of spawning. Growth rates were estimated by fitting von Bertalanffy growth curves to growth increment data by the method of FABENS (1965). For this calculation we excluded growth data where the period at liberty was less than a year, in order to avoid bias from differential seasonal growth. A simple model was developed to examine the biomass yield (BEVERTON & HOLT, 1957) and production of eggs (SLUCZANOWSKI, 1984) during the life of a cohort. We used the following equations as inputs. In the absence of published fecundity estimates for Haliotis fulgens in Baja California we used: a mean fecundity (F) of 2.67 million eggs at 172 mm length, derived from TUTSCHULTE (1976) and TUTSCHULTE & CONNELL (1988) for H. fulgens at Santa Catalina; a length-weight relationship of W = 2.72 x 10°> L** (after GUZMAN DEL PROO, in press); and a mean length at sexual maturity of 105 mm (this paper). We assumed fecundity was linear with total weight (W) and derived the equation: F = 0.0026W — 0.61. In these equations W is expressed in g, L in mm, and F in millions of eggs. Parameters of the von Bertalanffy growth equation are those given for females in this paper. Page 326 Table 1 Values of the parameters of the von Bertalanffy growth equation for Haliotis fulgens at Los Morros. The total number (32) includes 4 that were sexually immature. K 16s Sex n (yr!) SE (mm) SE Male 15 0.39 0.10 181.2 8.3 Female 13 0.41 0.09 179.9 8.1 Total 32. 0.38 0.04 183.1 6.1 RESULTS Growth and Size at Maturity Annual increment data for mark-recapture data are plotted in Figure 2 and estimates of the parameters of the von Bertalanffy growth equation are given in Table 1 for males, females, and all data, which includes juveniles. The slight differences in growth rate between the sexes are not significant. We did not have data on the growth rate of Halhiotis fulgens below about 80 mm in this study. However, ‘TURRUBIATES (1989) found that the growth rate of juve- niles was 35 mm per year for the first 2 years at a different site in Bahia Tortugas. Assuming that the mean length of H. fulgens is 70 mm at 2 years, a mean growth curve can be constructed for the Los Morros site (Figure 3). A plot of the percent sexually mature individuals against size (Figure 4) shows that sexual maturity occurs between 70 and 140 mm SL. Fifty percent are sexually mature at about 105 mm SL, suggesting that sexual maturity is at- tained at about 3 years of age. The sex ratio changes from 1:2 (males to females) for (@)) O aN oO INCREMENT (mm y~!) N oO 60 80 The Veliger, Vol. 34, No. 4 those <120 mm SL to 1.17:1 for those >120 mm SL. The change in sex ratio with size is significant (Cochrans Test: x? = 4.07; P < 0.05) and unless differential mortality occurs, suggests a slightly faster growth rate of males than females because of the higher proportion of mature females in smaller size classes. Emigration from the study site was about 12% of those recaptured. Four individuals were found during extensive searching for 50 m beyond the marked boundary. The mean distance moved by these abalone was about 14 m (maximum 25 m) in a year, in each case in the direction of the approaching swell. In addition, fishermen reported three more tagged abalone that were estimated to have moved about 50 m. Egg-Per-Recruit and Yield-Per-Recruit Analysis Egg-per-recruit analysis and biomass yield (Figure 5) are presented as a percentage of the maximum number of eggs produced by a cohort, or the maximum weight of the cohort, as the case is, for three rates of M—0.1, 0.2, and 0.3—for a range of ages at first capture. We chose a high, fixed value of F for the analysis because this is the most realistic assumption of the intensity of fishing during the recent history of the fishery (see Dis- cussion). It is also more useful for management because, in the future, control of fishing is likely to be more easily achieved by an output control, such as a size limit, than an input control, such as a direct control of effort. The results show that egg production increases more or less monotonically from ages 5 to 10 years for the three chosen values of M, whereas biomass decreases from max- ima at 4-8 years according to the value of M. Male Female Indeterminate 100 120 140 160 INITIAL LENGTH (mm) Figure 2 Plot of annual increment data for Haliotis fulgens at Los Morros for males, females, and those of indeterminate sex. S. A. Shepherd e¢ al., 1991 160 120 80 LENGTH (mm) 40 2 4 6 Page 327 Bahia Tortugas Punta Abreojos Santa Catalina 8 10 2 14 AGE (years) Figure 3 Growth curves of Haliotis fulgens at Los Morros (Bahia Tortugas) (this study), Punta Abreojos (GUZMAN DEL PROO & MarIN, 1976), and Santa Catalina, California (TUTSCHULTE & CONNELL, 1988). DISCUSSION Growth, Size at Maturity, Sex Ratio, and Mortality Previously published growth rates of Haliotis fulgens are given in Table 2 (see review by Day & FLEMING, in press) and compared graphically in Figure 3. The growth rates of H. fulgens are almost identical at Punta Abreojos and Los Morros, and both are much faster, especially at smaller sizes, than that recorded by TUTSCHULTE & CONNELL (1988) at Santa Catalina Island. This is consistent with GUZMAN DEL PROO’s (1989) statement that the growth rate of abalone decreases with increasing latitude along the Californian peninsula. Compared with the growth rates of other abalone species (DAY & FLEMING, in press) this species in central Baja California must rank among the fastest growing abalone in the world. The size at sexual maturity from our data occurs over a wide size range (70-140 mm), an only slightly greater range than that given by TUTSCHULTE & CONNELL (1981), 61-128 mm, although these authors suggested a much slower rate of growth. Our values are also less than that given by GUZMAN DEL PROo (in press) in his review of earlier work; 50% of the population was mature at 141 mm SL. Size at sexual maturity has been suggested to be age-dependent rather than size-dependent (PRINCE, 1989), and this accords with our experience (SHEPHERD & LAws, 5 PERCENT MATURE 80 60 40 / N 20 nose 70 80 90 6100 110 120 130 140 SHELL LENGTH (mm) Figure 4 Percentage of sexually mature Haliotis fulgens with size. Page 328 Haliotis fulgens LENGTH AT FIRST CAPTURE (mm) The Veliger, Vol. 34, No. 4 147.8 165.7 Witacite Uae UAed5 OF 179.4 {MOXOS ; + + {|__| | |__| — je 120 0.3 0.2 BIOMASS ea % 80 + 0.1 A x Ey ” M 6 60 —- A G ‘s 0.1 P . Un poo & R ae Nea Al fe} fe) iN Dp +09; vo va ISK H U NY | Ss 5 y we \ 40 = T Y | 0.2 fe) we N 20 ye yo Vian ee + 20 a Ye 0.3 VOSEGGS a) + = oe © 5 6 ig 9g 10 AA 12 18 14 15 l | 8 AGE AT FIRST CAPTURE Figure 5 Yield-per-recruit and egg-per-recruit curves for Haliotis fulgens at M values of 0.1, 0.2, and 0.3, for high values of F(= 8). 1974; GUZMAN DEL PROO, in press). Because growth rates can vary greatly between reefs, the size at sexual maturity would also be expected to be variable between sites. The significance of a changing sex ratio with size is still not clear (see , TUTSCHULTE & CONNELL, 1981). SHEPHERD & HEARN (1983) suggested that differential growth be- tween the sexes was the most likely cause of changing sex ratios. This implies that allocation strategies may vary between the sexes in a population, a possibility that de- serves further study. Our tagging experiment was conducted in a way that allowed for measurement of the natural mortality rate (M) by the BEINSSEN & POWELL (1979) method. However, of the 533 marked abalone released only 10% were recap- tured; the obtained value of M (0.31) did not differ sig- nificantly from zero, and is of no value. The experiment illustrates the problems encountered when the recapture rate is low. The low recapture rate was due partly to the cryptic nature of Haliotis fulgens in a deeply creviced hab- itat that contained many large boulders that could not be overturned, partly to the abundance of Phyllospadix and algae which made searching difficult, and partly to low visibility due to red tide. A low searching efficiency is not inconsistent with a high value of F; the former applies to Table 2 Parameters of the von Bertalanffy growth equation for Haliotis fulgens at different sites. K Lo Place Latitude (yr!) (mm) Santa Catalina 37°N 0.10 205 Punta Abreojos 26°40'N 0.38 171 Punta Abreojos 26°40'N 0.37 170 Sex Authority both TUTSCHULTE & CONNELL (1988) male GUZMAN DEL PROO & MarIN (1976) female GUZMAN DEL PROO & MarIN (1976) S. A. Shepherd e¢ a/., 1991 the smaller, cryptic fraction of the population whereas the latter applies to the larger, more exposed fraction. Further, the study site may have contained more cryptic habitat than is typical of fished habitats. The problem of low searching efficiency was experienced by SHEPHERD et al. (1982) in measuring M for H. rubra, a species of similar cryptic habit. SHEPHERD & BREEN (in press) have dis- cussed the problem and recommended a pilot experiment to obtain some idea of the likely movement and recapture rate. Estimates of M for Haliotis fulgens range from 0.07 to 0.53 (reviewed by SHEPHERD & BREEN, in press) but we think the high values are not realistic for adult abalone. For the purpose of the egg-per-recruit analysis we use M values of 0.1-0.3, which should span the likely range of M. Implications for Management The history of the Mexican abalone fishery in Baja California is described by GUZMAN DEL PROO (in press), and salient features are summarized here. From the early 1960s the fishery was subject to high fishing pressure. From 1970 to 1985 the combined annual catch of Haliotis fulgens and H. corrugata in Zones I-IV (the mid-Baja California coast that includes Bahia Tortugas) declined to one-fifth, although the proportion of H. fulgens increased, indicating a proportionally smaller decline of that species. The density of H. fulgens apparently declined to one-third in the same period (GUZMAN DEL PROO, in press). It seems reasonable to assume that the fishing mortality rate (/) was high (>1.0) during this period. Size limits existed in name only until 1984, when a limit of 145 mm SL was enforced by requiring divers to land abalone in the shell. However, Haliotis fulgens has a cryptic habitat to at least 140 mm SL (TUTSCHULTE, 1976, un- published), so that, even under intense fishing, few indi- viduals <130-140 mm SL would have been taken. We conservatively assume that the age of first capture is 5 years (=148 mm SL). On the basis of the above assumptions, egg production since 1970 would have been in the range of 6 to 17% of the maximum possible according to the chosen value of M. Intuitively, this seems extremely low, and raises the pos- sibility that recruitment overfishing (reduction of parent stock to a level that adversely affects recruitment) may have occurred, and precipitated the decline in catch and density during the history of the fishery (GUZMAN DEL PROO, in press). NASH (in press) presented evidence sug- gesting that at least 50% of the egg production potential should be maintained in an exploited stock. SLUCZANOWSKI (1984, 1986) suggested minimum levels of 40%. SHEPHERD (1991) found that recruitment failed in an isolated pop- ulation, when the population density declined to around 32% of the virgin population and when the fraction of the population that aggregated for spawning fell to 6%. How- ever, such values are at best suggestions only until the stock-recruitment relations in abalone are better known. Page 329 Until more information on natural mortality is avail- able, it would be prudent to increase the size limit to around 165 mm SL to ensure 20-40% egg production. This mea- sure would be certain to have serious social and economic implications, which would need to be explored. ACKNOWLEDGMENTS This study was supported by a grant (PCECNA-050769) under the Australia-Mexico agreement on Science and Technology. We are grateful to: the Sociedad Cooperativa de Produccion Pesquera, Bahia Tortugas, S.C.L. for co- operation and support; Centro de Investigacion Cientifica y de Educacion Superior de Ensenada for facilities and support for the second author; and Centro de Acuacultura de Bahia Tortugas for diving equipment and field support. The following assisted with the diving or in the boat: Job Alcantara, Raul Mateos, Luis Guzman, Oscar Alvarez Patron, Ramon Quezada, Jesus Garcia Constante, Ramon Ayala, Bernardo Gomez, Armando Pinuelas, and Agustin del Valle. Ms. K. Hill gave statistical advice, and B. Wall- ner, Dr. M. J. Tegner, and Dr. P. A. Breen and an anonymous referee gave helpful criticism on the manu- script. LITERATURE CITED BEINSSEN, K. & D. POWELL. 1979. Measurement of natural mortality in a population of blacklip abalone, Notohaliotis ruber. Rapports Precis- Verbal Reunion Conseil internation- al pour la Exploration de la Mer 175:23-26. BEVERTON, R. J. H. & S. J. HOLT. 1957. On the dynamics of exploited fish populations. U.K. Ministry of Agriculture and Fisheries, Food and Fisheries Investigations (Ser.2) 19:1- 533. BREEN, P. A. In press. A review of models used for stock assessment in abalone fisheries. Jn: S. A. Shepherd, M. J. Tegner & S. A. Guzman del Proo (eds.), Abalone of the World: Biology, Fisheries and Culture. Blackwells: Oxford. Day, R. W. & A. E. FLEMING. In press. The determinants and measurement of abalone growth. Jn: S. A. Shepherd, M. J. Tegner & S. A. Guzman del Proo (eds.), Abalone of the World: Biology, Fisheries and Culture. Blackwells: Ox- ford. FABENS, A. J. 1965. Properties and fitting of the von Bertalanffy growth curve. Growth 29:265-289. GUZMAN DEL PrOo, S. A. 1989. Problemas y perspectivas de las investigaciones pesqueras sobre los abulones de Mexico. Pp. 297-305. In: Proceedings of the Workshop Australia- Mexico on Marine Science. Merida, Mexico. GUZMAN DEL Proo, S. A. In press. A review of the biology of abalone and its fishery in Mexico. Jn: S. A. Shepherd, M. J. Tegner & S. A. Guzman del Proo (eds.), Abalone of the World: Biology, Fisheries and Culture. Blackwells: Oxford. GUZMAN DEL Proo, S. A. & A. MARIN. 1976. Resultados preliminares sobre crecimiento de abulon amarillo y azul (Haliotis corrugata y H. fulgens) en Punta Abreojos, B.C. Instituto Nacional de Pesca. INP/SC. No. 17:11 pp. Nasu, W. J. In press. An evaluation of egg-per-recruit-analysis as a means of assessing size limits for blacklip abalone (Hal- totis rubra) in Tasmania. In: S. A. Shepherd, M. J. Tegner Page 330 & S. A. Guzman del Proo (eds.), Abalone of the World: Biology, Fisheries and Culture. Blackwells: Oxford. PRINCE, J. D. 1989. The fisheries biology of the Tasmanian stocks of Haliotis rubra. Ph.D. Thesis, University of Tas- mania, Hobart. PRINCE, J. D. 1991. A new technique for tagging abalone. Australian Journal of Marine and Freshwater Research 42: 101-106. SHEPHERD, S. A. 1991. A review of the concept of stock in abalone fisheries: implications for the role of refugia in con- servation. American Fisheries Society. San Antonio, Texas (abstract only). SHEPHERD, S. A. & P. A. BREEN. In press. Mortality in abalone: its estimation, variability and causes. Jn: S. A. Shepherd, M. J. Tegner & S. A. Guzman del Proo (eds.), Abalone of the World: Biology, Fisheries and Culture. Blackwells: Ox- ford. SHEPHERD, S. A. & W. S. HEARN. 1983. Studies on southern Australian abalone (genus Haliotis). 1V. Growth of H. lae- vigata and H. ruber. Australian Journal of Marine and Freshwater Research 34:461-475. SHEPHERD, S. A., G. P. KiRKwoop & R. L. SANDLAND. 1982. Studies on southern Australian abalone (genus Halzotis). III. Mortality of two exploited species. Australian Journal of Marine and Freshwater Research 33:265-272. SHEPHERD, S. A. & H. M. Laws. 1974. Studies on southern Australian abalone (genus Haliotis). 11. Reproduction of five species. Australian Journal of Marine and Freshwater Re- search 25:49-62. SLUCZANOWSKI, P. R. 1984. A management oriented model of The Veliger, Vol. 34, No. 4 an abalone fishery whose substocks are subject to pulse fish- ing. Canadian Journal of Fisheries and Aquatic Sciences 41: 1008-1014. SLUCZANOWSKI, P.R. 1986. A disaggregate model for sedentary stocks: the case of the South Australian abalone. Canadian Special Publications in Fisheries, Aquatic Sciences 92:393- 401. TEGNER, M. J., P. A. BREEN & C. E. LENNERT. 1989. Pop- ulation biology of red abalones (Haliotis rufescens) in south- ern California, and management of the fishery. Fishery Bul- letin 87:313-339. TURRUBIATES, J. R. 1989. Edad, crecimiento y reproduccion del abulon azul Haliotis fulgens Philippi 1845 (Mollusca: Gastropoda) de Bahia Tortugas, B.C.S. Tesis de Maestro en Ciencias, Instituto Politecnico Nacional, Mexico D.F. TURRUBIATES, J. R., M. Ortiz, F. Lopez, R. AYALA & B. GOMEZ. 1987. Informe de la temporada de pesca 1985- 86 de abulon, Haliotis spp en la costa occidental de la Penin- sula de Baja California. Resumenes de VII Congreso Na- cional de Oceanografia, Ensenada, B.C. July 1987. TUTSCHULTE, T. C. 1976. The comparative ecology of three sympatric abalones. Ph.D. Thesis, University of California, San Diego. 355 pp. TUTSCHULTE, T. C. & J. H. CONNELL. 1981. Reproductive biology of the species of abalones (Haliotis) in southern Cal- ifornia. The Veliger 23:195-206. TUTSCHULTE, T. C. & J. H. CONNELL. 1988. Growth of three species of abalone (Haliotis) in southern California. The Veliger 31:204-213. The Veliger 34(4):331-334 (October 1, 1991) THE VELIGER © CMS, Inc., 1991 Growth Rings Within the Statolith Microstructure of the Giant Squid Architeuthis GEORGE D. JACKSON Department of Marine Biology, James Cook University of North Queensland, Townsville, Queensland, Australia 4811 Cc. Gc. LU Department of Invertebrate Zoology, Museum of Victoria, Russell Street, Melbourne, Victoria, Australia 3000 MALCOLM DUNNING ueensland Department of Primary Industries, Fisheries Branch, Brisbane, p Y/ Queensland, Australia 4001 Abstract. The microstructure of a statolith taken from a juvenile, female specimen of giant squid Architeuthis sp. (42.2 cm ML) trawled off southern Australia was examined. The statolith was mounted in thermoplastic cement and ground and polished on both the anterior and posterior surfaces to reveal the growth rings from the nuclear region to the edge. The growth rings were similar in appearance to daily growth rings observed in other oegopsid and myopsid squids. Based on replicate ring counts, the Architeuthis specimen was 153 days old and had an average daily growth rate of 2.76 mm per day. The presence of growth rings within the statoliths of the giant squid indicates that growth rings exist across the spectrum of cephalopod size from the smallest species, /diosepius, to the largest of all cephalopods, Architeuthis. INTRODUCTION Growth rings have been observed in the statoliths of many cephalopod species: in the oegopsid squids Illex illecebrosus (HurLEY & BECK, 1979), Illex argentinus (RODHOUSE & HATFIELD, 1990), Todarodes sagittatus (ROSENBERG et al., 1981), and Gonatus fabricii (KRISTENSEN, 1980); in the myopsid squids Alloteuthis subulata (LIPINSKI, 1986), Pho- tololigo edulis (NATSUKARI et al., 1988), Heterololigo bleekeri (KINOSHITA, 1989), Sepioteuthis lessoniana (JACKSON, 1990a), Loliolus noctiluca (JACKSON, 1990b), Loligo forbes: (MARTINS, 1982), Loligo opalescens (SPRATT, 1978), Loligo gah: (RODHOUSE & HATFIELD, 1990), and Loligo chinensis (JACKSON, 1990b). Growth rings have been shown to exist also in the sepioids Rossia glaucopis (KRISTENSEN, 1980) and Idiosepius pygmaeus (JACKSON, 1989). Here we report on the statolith ring structure of a juvenile giant squid (Architeuthis sp.) that was trawled off the southern coast of Australia. MATERIALS anD METHODS The specimen of Architeuthis sp. (a female, 42.2 cm ML) was captured on 30 January 1982 on a cruise of the CSIRO FRV Soela using an International Young Gadoid Pelagic Trawl (IYGPT). The tow was taken off New South Wales Australia (33°44'S, 153°00’E) between 1845 and 1950 hr, obliquely from the surface to a depth of 600 m. Bottom depth at the locality was approximately 2000 m. Details of the specimen will be published elsewhere (Lu and Dun- ning, unpublished). The statoliths were removed before preservation of the specimen, placed in 70% ethanol, and Page 332 The Veliger, Vol. 34, No. 4 Figure 1 Growth rings within the statolith microstructure of a juvenile Architeuthis sp. A. Dorsal dome region of statolith; scale bar = 80 um. B. Close-up of ring structure within the dorsal dome showing clear ring sequence to the statolith margin; note the unusual discontinuity within the ring structure approximately 17 rings in from the margin; scale bar = 40 um. G. D. Jackson et al., 1991 subsequently examined in January 1990. The years of preservation in ethanol did not appear to damage the stato- liths. One of the statoliths was embedded in the thermoplastic cement Crystal Bond®. The ring structure on the edge of the dorsal dome region was visible immediately upon being embedded in the cement. However, the statolith required both grinding and polishing on both the anterior and pos- terior surfaces to produce a thin section and to reveal the rings deeper within the microstructure. Grinding and pol- ishing techniques were the same as previously described (JAcKsoN, 1990a, b). RESULTS anp DISCUSSION Specimen Identification The specimen of this study was identified as Architeuthis sp. on the basis of several distinguishing features: it pos- sessed a straight simple funnel-locking cartilage, the buccal connectives were attached to the dorsal border of arm IV, and the tentacular club had four rows of suckers, with those on the medial rows of the manus much larger and those on the marginal rows small. Also, a distinct cluster of numerous small suckers and knobs were at the proximal end of the manus, and two longitudinal rows of alternating suckers and pads were on the tentacular stalks. The spec- imen is lodged at The Museum of Victoria (registration number: F57913). Statolith Analysis The grinding and polishing of the Architeuthis statolith produced a translucent section in which the microstruc- tural ring sequence was visible (Figure 1A) with ring def- inition very clear to the outer edge of the dorsal dome (Figure 1B). Although the ring sequence could be traced back to the nuclear region, no clear point marking the start of the ring sequence could be seen. Examination of more statoliths will be needed to define accurately the nuclear region. The growth rings were similar in structure to growth rings observed in loliginids, for example by NATSUKARI et al. (1988) and JACKSON (1990a, b), and in other oceanic squids, for example by KRISTENSEN (1980), ROSENBERG et al. (1981), and RODHOUSE & HATFIELD (1990). The ring structure was bipartite and consisted of a narrow dark zone and a broader light (more translucent) zone. Three replicate counts of all the growth rings from the nuclear region to the edge were very close (154, 154, 150). Architeuthis represents the upper end of the size range of cephalopods, with individuals reaching huge dimensions of over 20 m total length and a mantle length of 6 m (ROPER et al., 1984). However, biological data for this species are fragmentary and mostly derived from the ex- amination of a relatively few stranded specimens (CLARKE, 1966; ROPER & Boss, 1982; BOYLE, 1986). Although it would be difficult to validate the periodicity of the growth rings within the Architeuthis statoliths, the Page 333 rings do resemble growth rings that have been shown to be laid down daily in other species. Assuming the daily formation of growth rings and a mantle length at hatching of approximately 1 mm, the specimen examined would have been about 153 days old with an average growth rate of 2.76 mm per day. Obtaining statolith age estimates from a number of dif- ferent-sized individuals of Architeuthis would allow a more accurate determination of the form of the growth curve for this squid. Statolith growth ring analysis has now spanned the en- tire size range in cephalopods, from the tiny /diosepius (<2 cm ML) (JACKSON, 1989) to this specimen of giant squid, Architeuthis (42.2 cm ML). The maximum size of Archi- teuthis indicates that statolith rings are laid down in ceph- alopods over a size range of over three orders of magnitude. Future research on the aging of oceanic squids promises to provide insights into the growth dynamics of many other poorly understood species. LITERATURE CITED BoyLe, P.R. 1986. Report ona specimen of Architeuthis strand- ed near Aberdeen, Scotland. Journal of Molluscan Studies 52:81-82. CLARKE, M. R. 1966. A review of the systematics and ecology of oceanic squids. Advances in Marine Biology 4:91-300. Hur ey, G. V. & P. Beck. 1979. The observation of growth rings in statoliths from the ommastrephid squid Illex ille- cebrosus. Bulletin of the American Malacological Union, Inc., pp. 23-25. Jackson, G. D. 1989. The use of statolith microstructures to analyze life-history events in the small tropical cephalopod Idiosepius pygmaeus. Fishery Bulletin, U.S. 87:265-272. Jackson, G. D. 1990a. Age and growth of the tropical near- shore loliginid squid Sepioteuthis lessoniana determined from statolith growth ring analysis. Fishery Bulletin, U.S. 88: 113-118. Jackson, G. D. 1990b. The use of tetracycline staining tech- niques to determine statolith growth ring periodicity in the tropical loliginid squids Loliolus noctiluca and Loligo chinen- sis. The Veliger 34:395-399. KINnosHiTA, A. 1989. Age and growth of loliginid squid, Het- erololigo bleekeri. Bulletin of the Seikai Regional Fisheries Research Laboratory 67:59-69. KRISTENSEN, T. K. 1980. Periodical growth rings in cephalopod statoliths. Dana 1:39-51. LiPINsKI, M. 1986. Methods for the validation of squid age from statoliths. Journal of the Marine Biological Association of the United Kingdom 66:505-524. Martins, H.R. 1982. Biological studies of the exploited stock of Loligo forbesi (Mollusca: Cephalopoda) in the Azores. Journal of the Marine Biological Association of the United Kingdom 62:799-808. NATSUKARI, Y., T. NAKANOSE & K. Opa. 1988. Age and growth of loliginid squid Photololigo edulis (Hoyle, 1885). Journal of Experimental Marine Biology and Ecology 116:177-190. RopuHousE, P. G. & E. M. C. HATFIELD. 1990. Age deter- mination in squid using statolith growth increments. Fish- eries Research 8:323-334. Roper, C. F. E. & K. J. Boss. 1982. The giant squid. Scientific American 246:82-88. Page 334 Roper, C. F. E., M. J. SWEENEY & C. E. NAUN. 1984. Ceph- alopods of the world. An annotated and illustrated catalogue of species of interest to fisheries. FAO Fisheries Synopsis No. 125(3), 277 pp. ROSENBERG, A. A., K. F. WiporG & I. M. BECH. 1981. Growth of Todarodes sagittatus (Lamarck) (Cephalopoda, Om- The Veliger, Vol. 34, No. 4 mastrephidae) from the Northeast Atlantic, based on counts of statolith growth rings. Sarsia 66:53-57. SpraTT, J.D. 1978. Age and growth of the market squid Loligo opalescens Berry, in Monterey Bay. California Department of Fish and Game Fish Bulletin 169:35-44. The Veliger 34(4):335-343 (October 1, 1991) THE VELIGER © CMS, Inc., 1991 Seasonal Variation in Biochemical Composition of Three Size Classes of the Chilean Scallop Argopecten purpuratus Lamarck, 1819 by GLORIA MARTINEZ Departamento de Biologia Marina, Facultad de Ciencias del Mar, Universidad Catdlica del Norte, Casilla 117, Coquimbo, Chile Abstract. Seasonal changes in protein, carbohydrate, and lipid levels of different size classes of the Chilean scallop Argopecten purpuratus Lamarck, 1819, were examined in order to describe these changes, both as a function of reproductive activity and age. Three size classes of individuals were examined: 20, 50, and 80 mm mean length. Separate analyses were made for adductor muscle, mantle, and gonad body components. Protein was always the most abundant substrate in all components. Adductor muscle protein content exhibited a different seasonal pattern for each size class of animals. Adductor muscle lipid levels varied significantly only in the middle size class, and the carbohydrate content showed a similar seasonal course for all size classes. The gonad had the greatest variation in biochemical com- position, not only seasonally, but also with size class. A negative correlation between gonad index and carbohydrate content of all examined components was observed in summer for 80-mm scallops, indicating that, in A. purpuratus, this metabolic substrate is being utilized for the maturation of gametes. In ripe gonads, lipid and protein levels of the female portion were higher than those of the male portion, indicating that these substrates become the constituent and reserve materials for larvae. Biochemical analyses of the mantle revealed clear differences among the three size classes of individuals, suggesting that this tissue could be a site for storage of metabolic substrates to be utilized for growth rather than for gametogenesis. INTRODUCTION The scallop Argopecten purpuratus Lamarck is one of the most commercially important bivalves in northern Chile. After being intensively fished for several years, its culture under managed conditions has been developed. DIsALVO et al. (1984) were the first to study the feasibility of rearing this scallop in mass culture and described the entire growth cycle from egg to the attainment of adult size. Argopecten purpuratus is a functional hermaphrodite and presents a continuous reproductive cycle with a major spawning peak in late summer and a minor one in autumn (BROWN & GUERRA, 1982; WOLFF, 1988). Seasonal changes in the composition and utilization of metabolic substrates in marine bivalves have generally been attributed to reproductive activity (for reviews see GIESE, 1969; GABBOTT, 1976, 1983). However, the studies of Pectinidae have shown that the manner in which nutrient reserves are utilized for gametogenesis is variable. For Pecten maximus (FAVERIS, 1987), Chlamys opercularis (TAYLOR & VENN, 1979), and Argopecten irradians con- centricus (BARBER & BLAKE, 1981), energy for the mat- uration of gametes comes from reserves of glycogen and protein stored in the adductor muscle. In Argopecten ir- radians irradians, gametogenesis occurs mainly at the ex- pense of adductor muscle protein and lipid reserves (EPP et al., 1988). The energy for this process in Chlamys sep- temradiata (ANSELL, 1974) comes mainly from ingested food, whereas in Placopecten magellanicus it comes from both stored reserves and ingested food (THOMPSON, 1977; ROBINSON et al., 1981). The present study investigates seasonal changes of the principal biochemical constituents of some tissues of Ar- gopecten purpuratus. Individuals of different sizes are ex- amined in an attempt to explain seasonal patterns, not only as a function of reproductive activity, but also as a function of age. MATERIALS anp METHODS The scallops Argopecten purpuratus were obtained from an experimental culture in Herradura Bay, Coquimbo, Chile Page 336 GONAD INDEX (%) Figure 1 Seasonal changes in the gonad index of three size classes of Argopecten purpuratus. Number within columns is (7). (30°S). Three size classes of animals were chosen: 15-25 mm, 45-55 mm, and 75-85 mm in shell length. I shall refer to them by their mean values: 20, 50, and 80 mm, respectively. Three times a week, 6 to 10 individuals of each size class were sampled for biochemical analyses. This sampling was done during the following periods: summer, from 15 December to 30 January; autumn, from 15 March to 30 April; winter, from 15 June to 30 July; and spring, from 15 September to 30 October. Individuals were cleaned, blotted dry, and weighed with the shell and without it. Adductor muscle, gonad, and mantle body components were separated, weighed, and dried to constant weight at 70°C. When the gonads ap- peared ripe, male and female portions were easily distin- guished and dissected separately. The male portion has a light creamy white color while the female is orange colored. Twenty milligrams of dried tissue was homogenized in 1 mL of deionized water and subsamples of this homogenate were used to determine protein, carbohydrate, and lipid levels (ug/mg dry weight). Proteins were assayed by the Lowry method (Lowry et al., 1951) using bovine serum albumin as the calibration standard. Carbohydrates were determined using the phe- nol-sulfuric acid method of DuBols et al. (1956) with minor modifications: one aliquot of the original homogenate was resuspended in 10% trichloroacetic acid, placed in a 65°C hot water bath for one hour, cooled, and centrifuged for 15 min at 6000 rpm. One milliliter of supernatant was taken and 2 mL of phenol reagent was added and mixed rapidly. Five milliliters of concentrated sulfuric acid was then added, mixed thoroughly, and heated in boiling water for 20 min. After cooling, optical density was read at 490 The Veliger, Vol. 34, No. 4 nm on a Shimadzu spectrophotometer using oyster gly- cogen as the standard. Lipids were extracted from 0.2 mL of the original homogenate with chloroform-methanol (2: 1). Portions of this extract were used for colorimetric de- termination with phosphovanillin reagent, using choles- terol for calibration (BLIGH & Dyer, 1959; PosTMA & STROES, 1968). The gonad index, used as an indicator of reproductive activity, was determined as the percentage of the total tissue weight of the animal that consisted of gonad. One-way and two-factor analyses of variance were used to test for differences in biochemical composition among seasons and size classes of individuals (STEEL & TORRIE, 1980). A Tukey’s test was applied to evaluate the signif- icance of the possible differences found (STEEL & TORRIE, 1980). RESULTS—GONAD INDEX The gonad index of Argopecten purpuratus exhibited a seasonal pattern that was different for each size class of individuals (Figure 1). The smallest class of A. purpuratus (20 mm) did not show significant changes in this index throughout the year. The other two classes (50 and 80 mm) showed the highest values in summer, which were coincident with visual estimation of a prespawning stage of maturity. Notwithstanding, in summer, 50-mm scallops showed a significantly lower index (Tukey’s test, P < 0.05) than 80-mm individuals. After this, the gonad index de- clined steadily in the 80-mm scallops to a minimum value in winter, which began to recover towards spring. In 50- mm animals, the index fell to a minimum value in autumn. RESULTS—BIOCHEMICAL COMPOSITION Adductor Muscle Analyses Protein: Of the three biochemical constituents analyzed, protein was always the most abundant (Figure 2A). This metabolic substrate exhibited seasonal variations that dif- fered according to the mean length of individuals (Table 1). In the 20-mm group, protein content remained fairly constant in summer and autumn but was significantly greater (P < 0.05) in winter. In 50-mm scallops, a small rise was present in autumn, after which there was a sig- nificant decrease (P < 0.05) in winter and a rapid recovery in spring. In the 80-mm size class, protein content re- mained fairly constant all year except for a significantly higher value (P < 0.05) in spring (Appendix 1). Carbohydrate: This substrate showed a clear seasonal pattern (Figure 2B), but two-factor analysis of variance indicated no variation of this pattern between size classes of scallops (Table 1). The carbohydrate levels in summer were rather low, increased in autumn, decreased (except in 20-mm animals) in winter, and then attained high values in spring. This last increase was as high as 363% in the largest individuals (Appendix 1). G. Martinez, 1991 Page 337 Mg/mg DRY WEIGHT Figure 2 Seasonal changes in protein (A), carbohydrate (B), and lipid (C) contents of adductor muscle of three size classes of Argopecten purpuratus. Lipids: Two-factor analysis of variance for this constituent showed that seasonal variation was independent of body size (Table 1). Nevertheless, statistical analyses of the dif- ferences (Tukey’s test) showed that these were significant only for the 50-mm individuals. The lipid content of these animals decreased significantly in autumn (Appendix 1). This low value was sustained in winter and then under- went a great increase (63%) in spring (Figure 2C). Gonad Analysis This tissue showed the greatest variation in the content of its biochemical components, not only with respect to season, but also (with the exception of lipids) with respect to scallop sizes (Figure 3, Table 2; for actual values see Appendix 2). Table 1 Two-factor analysis of variance for adductor muscle bio- chemical components of Argopecten purpuratus. Season and size are the main effects considered. ns, not significant; *0.01 < P < 0.05; **0.001 < P < 0.01; ***P < 0.001. d.f. PF Proteins season 3 Onset size 2; 8.12*** interaction 6 4.23** residual 59 Carbohydrates season 3 LSe/ As size 2 0.74 ns interaction 6 2.11 ns residual 59 Lipids season 3 5.24** size 2 2.24 ns interaction 6 1.17 ns residual 56 Proteins: As in adductor muscle, protein was the major organic constituent in the gonad. The smallest size class of animals exhibited the lowest value in summer, which thereafter increased steadily to a maximum in spring. The pattern of changes was exceptional in mid-length scallops; protein content was low in summer, increased 45% (P < 0.05) in autumn, then decreased significantly in winter, and again increased, 53% (P < 0.05), in spring. In the largest size class of animals, the summer value fell steadily towards the winter value when it amounted to only 61% of the summer level. After this, there was a rapid recovery in the spring. The winter value was statistically different from the values of the other three seasons. Comparisons within the same season show that, in summer, 80-mm- length scallops exhibited the highest protein level, whereas, during the rest of the year, 20- and 50-mm-length indi- viduals had larger values (Figure 3A, Appendix 2). Carbohydrate: The seasonal pattern for carbohydrate showed differences between size classes of animals (Figure 3B, Table 2). A significant increase (P < 0.01) in car- bohydrate content occurred for all size classes during au- tumn after very low levels in summer. In 50-mm scallops this increase amounted to 239%. There was then a sig- nificant decrease (P < 0.05) in winter, followed by a small recovery in spring, which was significant only for 50-mm animals. The spring value for the largest scallops was 116% higher (P < 0.05) than the summer value. Noteworthy differences in gonadal carbohydrate levels also occur between different size classes within the same season (Appendix 2). In summer and autumn, values for the biggest scallops are significantly less (P < 0.05) than Page 338 The Veliger, Vol. 34, No. 4 AN as Se B® 3 eo a : = ee o @ uu = > iam (a) m € > mn 3 3 (we 5 Q oh Figure 3 Seasonal changes in protein (A), carbohydrate (B), and lipid (C) contents of gonad tissue of three size classes of Argopecten pur- puratus. the corresponding values of the other two size classes of specimens. The mean carbohydrate content of all body components examined was related to the gonad index (GI) during the summer and, for 80-mm scallops, there was a negative correlation between these two variables, described by the equation: In carbohydrate = 4.57 — 0.097 GI d.f.=9 P= 0.025 r=-0.84 712=0.699 No significant correlation (7? < 0.3, P > 0.05) was found for the rest of the year, nor was one found for any other size class of animals in the same season. Lipids: Lipids showed a similar seasonal pattern in the Table 2 Two-factor analysis of variance for gonad biochemical components of Argopecten purpuratus. Season and size are the main effects considered. ns, not significant; *0.01 < P <= 0.05; **0/001 =P 20101-2200 0ik d.f. F Proteins season 3 Di MOF? size 2 14.34*** interaction 6 8.08*** residual 59 Carbohydrates season 3 41.69*** size 2 ISO interaction 6 5.44*** residual 59 Lipids season 3 20.47*** size 2 1.25 ns interaction 6 1.15 ns residual 53 three size classes of scallops (Figure 3C, Table 2), although for the smallest individuals, one-way ANOVA showed no statistical difference between seasons. The winter lipid levels were always significantly lower (with the above- mentioned exception) than the other seasonal values. Comparative analysis between female and male por- tions of ripe gonads: In summer, the gonads of 50- and 80-mm-length scallops appeared ripe, and female and male portions were analyzed separately for biochemical com- position. For these two size classes of animals, female portions showed significantly higher protein and lipid lev- els than male portions (Table 3). There was no difference in carbohydrate levels between the two gonadal portions of the same size class of scallops. The carbohydrate content in the female gonadal portion of 80-mm-length specimens was higher than in the female portion of 50-mm-length specimens (one-way ANOVA, F = 26.62, P < 0.001). Mantle Analyses Protein: Protein was the main biochemical constituent of mantle tissue (Figure 4). Two-factor analysis of variance (Table 4) showed there was no overall seasonal variation but, rather, a clear size effect on protein content. In every season except summer, protein mantle content was always significantly lower (P < 0.05) in 80-mm-length individuals than in smaller ones (Appendix 3). One-way ANOVA for the smallest scallops showed significant seasonal differ- ences (F = 5.38, P < 0.05) which a Tukey test showed to reside in lower summer than autumn and winter values. Carbohydrates: Mantle carbohydrate content exhibited a clear seasonal pattern of changes (Figure 4B). Moreover, G. Martinez, 1991 Page 339 Table 3 Protein, carbohydrate, and lipid levels of male and female portions of ripe gonads of two size classes of scallops. Values are means + SD (n = 5). ns, not significant; *0.01 < P < 0.05; **0.001 < P < 0.01; ***P < 0.001. Male 50-mm length proteins 452.73 + 13.58 carbohydrates 5.03 + 0.63 lipids 89.69 + 7.69 80-mm length proteins 394.94 + 25.98 carbohydrates 6.86 + 1.28 lipids Soy 22 5.7/9 ug/mg DRY WEIGHT Figure 4 Seasonal changes in protein (A), carbohydrate (B) and lipid (C) contents of mantle tissue of three size classes of Argopecten pur- puratus. Female F 567.69 + 45.59 5.84* 4.78 + 0.57 0.08 ns 176.94 + 27.64 9.24* 612.98 + 39.22 21.49** 8.06 + 0.26 0.81 ns 245.90 + 22.45 46.75 *** carbohydrate level not only changed with respect to season, but also with individual size (Table 4). In 50-mm animals, a very high value (248.67 + 62.50 ug/mg dry wt.) occurred in autumn, contrasting with a very low summer level in the smallest scallops amounting to only 5.98 + 1.23 ug/ mg dry wt. In general, each size class of individuals showed the maximum carbohydrate level during autumn and the min- imum in summer. In spite of a significant difference be- tween summer and autumn (P < 0.05), the largest spec- imens showed smaller seasonal variations in this organic constituent than did the other two size classes of scallops. Lipids: Mantle lipid content followed a clear seasonal pattern (Figure 4C) which was independent of the size class of the animals (Table 3). After summer, values de- creased during the autumn and winter and increased in Table 4 Two-factor analysis of variance for mantle biochemical components of Argopecten purpuratus. Season and size are the main effects considered. ns, not significant; *0.01 < P < 0.05; **0.001 < P < 0.01; ***P < 0.001. d.f. F Proteins season 3 1.28 ns size 2 19.87*** interaction 6 3.00* residual 60 Carbohydrates season 3 46.12*** size 2 28.43*** interaction 6 DOM Dre residual 60 Lipids season 3 9.14*** size 2 2.53 ns interaction 6 1.99 ns residual 55 Page 340 the spring. This increase was significant only in 20- and 50-mm-length individuals (P < 0.05). DISCUSSION Argopecten purpuratus is reproductive all year, with spawning peaks occurring in late summer and autumn (BROWN & GUERRA, 1982; DISALVO et al., 1984; WOLFF, 1988). This pattern coincides with the gonad indices of adult scallops presented here, which showed maximal mean values in summer decreasing towards autumn, although not attaining indices as low as in winter. Nevertheless, in mid-length specimens a peak occurred only during sum- mer, although this mean gonad index was well below the mean value shown by the largest scallops. According to the growth curve of A. purpuratus (DISALVO et al., 1984), 45- to 55-mm-length individuals are still in a rapid phase of growth, so we may consider this size class to be expe- riencing both somatic and germinal growth. In contrast to the observations by DISALVO et al. (1984) of gonadal material in specimens as small as 13 mm in length and the induction of spawning in individuals rang- ing in length from 21 to 27 mm, we did not find mature scallops under 25 mm in length. Moreover, our gonad indices showed very low values throughout the year, such that, in this context, we may consider animals of these size classes to be in a nonreproductive stage of their life cycles. Individuals 75 to 85 mm in length, which are in a slow- growing phase (DISALVO et al., 1984), besides representing the major population mode in the natural banks (SER- PLAC, unpublished data), are considered adult (repro- ductive) individuals. The biochemical composition of adult Argopecten pur- puratus showed a seasonal course whose most relevant feature was a decrease of carbohydrate content in the body components examined, associated with an increase of go- nadal indices and high gonadal lipid and protein levels. This seasonal course is similar to that followed by other marine bivalves. It comprises a storing of energy substrates during a reproductively quiescent period and their sub- sequent utilization to support gametogenesis (GABBOTT, 1976, 1983; GIESE, 1966, 1969; SAsTRY, 1979; BARBER & BLAKE, 1981, 1985). In the adductor muscle of adult scallops, protein content rose in spring after remaining fairly constant the rest of the year. A similar rise in this constituent level of phasic adductor muscle at the time of gonad restoration has been reported for Pecten maximus by FAVERIS (1987). Studies on Chlamys septemradiata by ANSELL (1974), Chlamys oper- cularis by TAYLOR & VENN (1979), Argopecten irradians concentricus by BARBER & BLAKE (1981), and Argopecten irradians irradians by Epp et al. (1988), among others, have shown that these pectinids store protein and carbohydrate in their adductor muscle as an energy reserve for game- togenesis. The spring rise in adductor muscle protein found in adult Argopecten purpuratus does not necessarily mean that The Veliger, Vol. 34, No. 4 this biochemical component is the energetic substrate for gametogenesis, because 20- and 50-mm-length individuals also showed high values in the spring. Moreover, the small- est specimens had already attained this level during winter, and mid-sized animals increased their muscle protein con- tent in autumn coincident with a fall of the gonad index, which remained low the rest of the year. The largest variations in Argopecten purpuratus muscles were found in the carbohydrate content, with low levels in summer and winter and higher levels in autumn and spring. This pattern was similar for gonads and for the three size classes of individuals examined. Spring increases in the three biochemical constituents analyzed might be explained by an increase of phytoplankton abundance dur- ing this season (URIBE, 1989). The higher level of car- bohydrate could represent the storage of reserves that the largest scallops would utilize for gametogenesis, the small- est for somatic growth, and the mid-sized individuals for both processes. DISALVO et al. (1984) showed that rapid growth of A. purpuratus occurs during the spring. In relation to the utilization of carbohydrates for ga- metogenesis, BARBER & BLAKE (1985) have stated that during the initial stages of this process, the bay scallop Argopecten irradians concentricus catabolizes primarily car- bohydrates and, as gametes mature and spawning begins, metabolism shifts to protein as the primary substrate. Sex- ual maturation in Pecten maximus occurs to the detriment of the phasic adductor muscle, which suffers a depletion of glycogen content (FAVERIS, 1987). Similar data have been reported for other pectinid bivalves such as Chlamys septemradiata by ANSELL (1974), Chlamys opercularis by TAYLOR & VENN (1979), and Placopecten magellanicus by ROBINSON et al. (1981). In A. purpuratus I have found very low carbohydrate levels during the summer when the go- nad is ripe and the individual is ready to spawn. The inverse correlation between gonad index and carbohydrate content in reproductively mature individuals indicates that, in A. purpuratus as in other scallop species, carbohydrates are important for the maturation of gametes. Lipids represent less than 10% of the dry weight in the muscle and mantle of adult Argopecten purpuratus and remain fairly constant throughout the year. They are al- ways more abundant in the gonad, however, and experi- ence great seasonal variations in this tissue related to oocyte development. Although these changes are not statistically significant in nonreproductive individuals, the lowest val- ues are found in winter and the highest in summer coin- cident with the maximal gonad index. Similar results were obtained for Chlamys opercularis where muscle lipid con- tent showed no clear seasonal change but increased greatly in the gonad during maturation (TAYLOR & VENN, 1979). High lipid levels were found in the ovary of Placopecten magellanicus from April until November, and then dropped as a result of spawning (ROBINSON et al., 1981). Chlamys tehuelcha showed an increase in lipid content of the gonad in November-December and again in February-March coincident with a semiannual spawning cycle (POLLERO et G. Martinez, 1991 Page 341 al., 1979). BESNARD (1987, 1988) stated that total lipid and triglyceride contents in the gonad of Pecten maximus faithfully reflect the course of sexual maturation, with highest levels being found during the period when oocytes are ready to be fertilized, thus assuring larval development. A high lipid content has also been reported in several bivalve larvae and its importance as an energy reserve has been established by HOLLAND & SPENCER (1973), MANN & GALLAGER (1985), and WHYTE et al. (1987). The importance of lipid as an energy source in the planktonic eggs and larvae of marine bivalves is clearly demonstrated in the different biochemical compositions of ripe female and male gonad portions of Argopecten pur- puratus. This pectinid showed a lipid content at least twice as large in the female portion as in the male portion. These results are comparable with those obtained for Chlamys septemradiata by ANSELL (1974) and for Placopecten ma- gellanicus by THOMPSON (1977) and ROBINSON et al. (1981); in both species the ripe female gonad showed approxi- mately twice as much lipid as the male. Nevertheless, in these pectinids, protein content in female gonads was less than in male gonads. In A. purpuratus, the protein level was higher in the female portion of the gonad than in the male. This difference might be related to the different reproductive characteristics of these pectinids: A. purpur- atus is a functionally hermaphroditic bivalve, whereas P. magellanicus and C. septemradiata are dioecious. In A. 1r- radians concentricus, another functionally hermaphroditic pectinid, the study of seasonal biochemical composition did not examine male and female gonad portions separately (BARBER & BLAKE, 1981; Epp et al., 1988). Analyses of the mantle tissue showed some surprising results, with clear differences occurring among the three size classes of Argopecten purpuratus. Nonreproductive specimens had high carbohydrate and protein levels during the autumn and winter. A second bloom of phytoplankton during autumn has been detected in Herradura Bay (URIBE, 1989), and these results might indicate that these smaller scallops store nutrients in the mantle. The present study suggests that biochemical components of adult Argopecten purpuratus follow a seasonal cycle re- lated to reproductive activities. Carbohydrate represents the major storage substrate utilized for gametogenesis and varies inversely with gonadal maturity. Lipids are accu- mulated in the ripe gonad to supply the metabolic needs of future larvae. The seasonal pattern differs between scal- lops in nonreproductive and reproductive stages and be- tween reproductive and growing stages of the life cycle, reflecting complex interactions among age, food supply, temperature, growth, and gametogenesis. ACKNOWLEDGMENTS This research was supported by grants from the Direccion General de Investigacién, Extension y Asistencia Técnica of Universidad Catolica del Norte. I thank the Departa- mento de Acuacultura for the supply of samples and X. Bennett, A. Rodriguez, L. Mettifogo, A. Rivera, and R. Vera for their technical assistance. LITERATURE CITED ANSELL, A. D. 1974. Seasonal changes in biochemical com- position of the bivalve Chlamys septemradiata from the Clyde Sea Area. Marine Biology 25:85-99. BaRBER, B. J. & N. J. BLAKE. 1981. Energy storage and utilization in relation to gametogenesis in Argopecten irra- dans concentricus (Say). Journal of Experimental Marine Biology and Ecology 52:121-134. BARBER, B. J. & N. J. BLAKE. 1985. Substrate catabolism related to reproduction in the bay scallop Argopecten irradians concentricus, as determined by O/N and RQ physiological indexes. Marine Biology 87:13-18. BESNARD, J. I. 1987. Lipid metabolism in the female gonad and larvae of the scallop Pecten maximus L. Sixth Interna- tional Pectinid Workshop. Menai Bridge (Wales). 15 pp. BESNARD, J. I. 1988. Etude des constituants lipidiques dans la gonade femelle et des larves de Pecten maximus L. Thése de Docteur en Biologie. Université de Caen. 154 pp. BLIGH, E. G. & W. F. Dyer. 1959. A rapid method of total lipid extraction and purification. Canadian Journal of Bio- chemistry and Physiology 37:911-917. Brown, D. & R. GUERRA. 1982. Ciclo reproductivo en dos poblaciones de Chlamys (Argopecten) purpurata (Mollusca: Bivalvia). Archivos de Biologia y Medicina Experimental 15:R-111. DISALVO, L. H., E. ALARCON, E. MARTINEZ & E. URIBE. 1984. Progress in mass culture of Chlamys (Argopecten) purpurata Lamarck (1819) with notes on its natural history. Revista Chilena de Historia Natural 57:35-45. Dusois, M., K. A. GILLIES, J. K. HAMILTON, P. A. REBERS & F. SMITH. 1956. Colorimetric method for the determina- tion of sugars and related substances. Analytical Chemistry 28:350-356. Epp, J.,. V. M. BricELJ & R. E. MALour. 1988. Seasonal partitioning and utilization of energy reserves in two age classes of the bay scallop Argopecten irradians irradians (La- marck). Journal of Experimental Biology and Ecology 121: 113-136. FAVERIS, R. 1987. Studies on the evolution of glycogen content of somatic and germinal tissues during the annual repro- ductive cycle in Pecten maximus. In: Sixth International Pec- tinid Workshop. Menai Bridge (Wales). 10 pp. GassoTT, P. A. 1976. Energy metabolism. Pp. 293-355. In: B. L. Bayne (ed.), Marine Mussels: Their Ecology and Physiology. Cambridge University Press: Cambridge, En- gland. GaBBoTT, P. A. 1983. Developmental and seasonal metabolic activities in marine molluscs. Jn: P. W. Hochachka (ed.), The Mollusca, Vol. 2. Academic Press: New York. GlEsE, A. C. 1966. Lipids in the economy of marine inverte- brates. Physiological Reviews 46:244-298. GIEsE, A. C. 1969. A new approach to the biochemical com- position of the mollusc body. Oceanography and Marine Biology, an Annual Review 7:175-229. HOLLAND, D. L. & B. E. SPENCER. 1973. Biochemical changes in fed and starved oysters, Ostrea edulis L. during larval development, metamorphosis and early spat growth. Journal of the Marine Biological Association of the United Kingdom 53:287-298. Lowry, O. H., N. J. ROSEBROUGH, A. L. FARR & R. J. RANDALL. 1951. Protein measurement with the Folin phenol reagent. Journal of Biological Chemistry 193:265-275. Page 342 Mann, R. & S. M. GALLAGER. 1985. Physiological and bio- chemical energetics of larvae of Teredo navalis L. and Bankia gould: (Bartsch) (Bivalvia: Teredinidae). Journal of Exper- imental Marine Biology and Ecology 85:211-228. POLLERO, R. J., M. E. RE & R. R. BRENNER. 1979. Seasonal changes of the lipids of the mollusc Chlamys tehuelcha. Com- parative Biochemistry and Physiology 64A:257-263. PosTMA, T. & J. A. P. STROES. 1968. Lipid screening in clinical chemistry. Clinica Chimica Acta 22:569-578. RosiInson, W. E., W. E. WEHLING, M. P. Morse & G. C. McLeEop. 1981. Seasonal changes in soft-body component indices and energy reserves in the Atlantic deep-sea scallop Placopecten magellanicus. Fishery Bulletin 79:449-458. Sastry, A. N. 1979. Pelecypoda (excluding Ostreidae). Pp. 113-292. In: A. C. Giese & J. S. Pearse (eds.), Reproduction of Marine Invertebrates. Academic Press: New York. STEEL, R. G. D. & J. H. Torrie. 1980. Principles and Pro- cedures of Statistics: A Biomedical Approach. McGraw Hill Inc.: New York. 633 pp. TayLor, A. C. & T. J. VENN. 1979. Seasonal variation in APPENDIX 1 Seasonal values for protein, carbohydrate, and lipid levels (ug/mg dry wt.) of adductor muscle of three size classes of Argopecten purpuratus. Values are means + SD. The Veliger, Vol. 34, No. 4 weight and biochemical composition of the tissues of the queen scallop Chlamys opercularis from the Clyde Sea Area. Journal of the Marine Biological Association of the United Kingdom 59:605-621. TuHompson, R. J. 1977. Blood chemistry, biochemical com- position, and the annual reproductive cycle of the giant scal- lop, Placopecten magellanicus, from southeast Newfoundland. Journal of the Fisheries Research Board of Canada 34:2104- 2116. URIBE, E. 1989. Fitoplancton. Jn: Estudio repoblamiento de recursos bentonicos area piloto IV Region. Edited by COR- FO, Chile. WuyteE, J. N. C., N. BoURNE & C. A. HopGson. 1987. As- sessment of biochemical composition and energy reserves in larvae of the scallop Patinopecten yessoensis. Journal of Ex- perimental Marine Biology and Ecology 113:113-124. Wo trF, M. 1988. Spawning and recruitment in the Peruvian scallop Argopecten purpuratus. Marine Ecology—Progress Series 42:213-217. APPENDIX 2 Seasonal values for protein, carbohydrate, and lipid levels (ug/mg dry wt.) of gonad tissue of three size classes of Argopecten purpuratus. Values are means + SD. Size 20 mm 50 mm 80 mm Protein summer 496.7 + 50.9 514.6 + 89.9 487.6 + 61.6 autumn 458.2 + 68.9 604.2 + 88.7 459.4 + 58.3 winter 590.6 + 29.1 428.7 + 54.4 480.9 + 29.4 spring 605.7 + 31.8 583.9 + 67.0 570.1 + 83.8 Carbohydrate summer 31.8 + 11.9 SyleSy ax alZAS) 64.4 + 56.1 autumn ST eersileri 131.9 + 58.5 86.8 + 23.5 winter 86.5 + 38.8 33.0 + 25.8 40.7 + 26.0 spring 141.9 + 53.4 115.3 + 88.7 188.7 + 39.2 Lipid summer 67.4 + 4.5 62:9 EEM1I232 55.1 + 10.0 autumn 62.9 + 18.2 45:2) + 15:6 64.0 + 30.5 winter 59.8 + 18.3 441+ 9.4 41.5+ 14.9 spring 72.1 + 20.8 72.0 + 13.1 59.7 + 10.7 Size 20 mm 50 mm 80 mm Protein summer 444.2 + 68.1 419.7 + 64.1 5Sile/ 216768 autumn (pile ses 535)-7/ 609.2 + 46.8 462.9 + 62.6 winter 661.1 + 98.7 398.5 + 68.4 324.8 + 95.9 spring 753.6 + 99.4 610.4 + 93.2 599.9 + 98.1 Carbohydrate summer 53.6 + 10.8 46.9 + 11.6 PADS 32 PII autumn 119.3 + 48.8 159.4 + 26.4 72.6 = 14.5 winter 53.9 + 24.6 Sy/Aeyas I7/I 31.9 + 14.7 spring 71.4 + 27.8 55.1 + 18.4 56.6 + 16.9 Lipid summer 130.9 + 35.3 135.0 + 40.9 170.6 + 25.4 autumn 118.5 + 46.9 127.1 + 25.8 164.9 + 33.0 winter 85.7 + 43.2 82.0 + 22.9 78.3 + 31.5 spring N28) a2 Bsyil 173.7 + 43.8 183.2 + 57.9 G. Martinez, 1991 Page 343 APPENDIX 3 Seasonal values for protein, carbohydrate, and lipid levels (ug/mg dry wt.) of the mantle tissue of three size classes of Argopecten purpuratus. Values are means + SD. Size 20 mm 50 mm 80 mm Protein summer 511.6 + 92.2 515.3 + 59.9 490.4 + 61.3 autumn 710.6 + 82.5 647.6 + 50.3 448.4 + 61.3 winter 702.8 + 78.3 553.1 + 99.2 476.9 + 98.1 spring 643.9 + 62.5 636.2 + 73.9 391.6 + 38.6 Carbohydrate summer 5S) ae 41 7 15.7 + 4.1 14.5 + 14.2 autumn 89.0 + 46.3 248.7 + 62.5 36:25-EA1353 winter 76.9 + 68.5 47.2 + 33.1 33.8 + 19.7 spring 39.9 + 15.6 39.9 + 19.4 26.6+7.5 Lipid summer 95.7 + 26.5 77.4 + 18.8 90.2 + 26.4 autumn 86.5 + 31.5 56.3 + 18.6 59.0 + 26.5 winter B33 a2 Aoi OL 222 61.1 + 16.4 spring We; 35 "S)S)0) 119.0 + 30.4 Ona 1ES The Veliger 34(4):344-353 (October 1, 1991) THE VELIGER © CMS, Inc., 1991 The Family Galeommatidae (Bivalvia: Leptonacea) in the Eastern Atlantic SERGE GOFAS Muséum National d’Histoire Naturelle, Laboratoire de Biologie des Invertébrés marins et Malacologie, 55 rue Buffon, 75005 Paris, France Abstract. Two new species of the Galeommatidae are described from West Africa: Galeomme coalita, unusual for the genus in having valves that may close almost completely, and Ephippodonta gregaria, the first known representative of its genus in the Atlantic. Galeomma coalita and the European species Galeomma turtoni (probably also the South African species Coleoconcha opalina) have parasitic dwarf males attached to the mantle, whereas E. gregaria is hermaphroditic. The range of Galeomma turtoni also includes West Africa. INTRODUCTION The Galeommatidae are a family of small marine bivalves that have attracted the attention of malacologists for their unusual characters: a trend towards expansion of the man- tle over the shell and the ability to crawl about on their foot. They are represented in the Indo-Pacific by many genera and species. Only two Atlantic species resemble the European Galeomma turtoni Sowerby, 1825, with a large ventral gape on the shell: the American Aclistothyra atlan- tica McGinty, 1955, and the South African Coleoconcha opalina Barnard, 1963. More species of Galeommatidae have now been described from Florida by MIKKELSEN & BIELER (1989) who provided detailed anatomical and bi- ological data. Other genera and species from the eastern Atlantic have been assigned to the family, but without data on the living animals and, thus, with great uncertainty. Collecting in West Africa has yielded new localities extending the known range of Galeomma turtoni, and ma- terial for two new species that are described herein. Field notes were taken on these and on European specimens of Galeomma turtoni collected alive. Museum abbreviations used in this paper are: ANSP, Academy of Natural Sciences, Philadelphia; MNCN, Mu- seo Nacional de Ciencias Naturales, Madrid; MNHN, Muséum National d’Histoire Naturelle, Paris; SAM, South African Museum, Cape Town; USNM, National Mu- seum of Natural History, Washington. TAXONOMY Family GALEOMMATIDAE Gray, 1840 Galeommatidae (corrected name, herein, for Galeomatidae Nordsieck, 1969, incorrect original spelling) is a junior homonym and synonym. Ephippodontidae (corrected name, herein, for Ephippiodontidae Scarlato & Starobogatov, 1979), type genus Ephippodonta Tate, 1889, is considered a synonym. Genus Galeomma Turton, 1825 Original reference: TURTON, 1825:361, pl. 13, fig. 1. Type species: Galeomma turtoni Sowerby in TURTON, 1825, by monotypy (see ICZN, Art. 69a, vii). Synonym: Parthenope Scacchi, 1833 (type species: P. formosa Scacchi, 1833, by monotypy). Galeomma turtoni Sowerby in Turton, 1825 Original reference: TURTON, 1825:361, pl. 13, fig. 1. Type material: Holotype USNM 199412 (WaREN, 1983:pl. 9, figs. 5-8). Synonyms: “Hiatelle de Poli’? Costa, 1828 (vernacular); Miatella Poli Costa in Scacchi, 1836, Hiatella poliana Costa in Philippi, 1844 (both first published as a syn- onym and not available). Parthenope formosa SCACCHI, 1833:8-10, 19. Galeomma pileum BRUSINA, 1866:42-43. Material examined: European Atlantic and Mediterra- nean—Herm, Channel Islands, 4 shells (Staadt collection, MNHN); Roscoff, Brittany, 2 shells (leg. Gofas 1976, MNHN); Guethary, Basque coast, Bay of Biscay, 3 spec- imens (leg. Gofas September 1988, MNHN)); Sagres, Al- garve, southern Portugal, 4 specimens (Mission Algarve, May 1988, MNHN); Cabo de Gata, Spain, 1 specimen (leg. Hergueta March 1986, MNCN); Marseille, 5 spec- imens (old collection MNHN); Marseille, 3 specimens (Jousseaume collection, MNHN); Toulon, 4 specimens (Petit collection, MNHN); Giottani near Cap Corse, Cor- sica, 2 specimens (MNHN). New occurrences—Ouaran, S. Gofas, 1991 ja Page 345 Explanation of Figures 1 to 5 Figures 1-5: Galeomma turtoni Sowerby in Turton. Figure 1. Exterior of shell of adult female from Guethary, Bay of Biscay (actual length 8.6 mm). Figure 2. Protoconch and initial part of teleoconch of the same specimen as in Figure 1 (scale bar is 100 um). Figure 3. Shell of dwarf male attached to the same specimen as in Figure 1 (actual length 770 um). Figure 4. Exterior of left valve and interior of right valve of a specimen from Cabo Ledo, Angola (actual length 5.4 mm). Figure 5. Protoconch of specimen in Figure 4 (scale bar is 100 um). near Dakar, Senegal, among rocks (/eg. Bouchet August 1973, MNHN); Cabo Ledo, Angola, under stones taken in fishing nets 10-40 m, 2 specimens (/eg. Gofas, MNHN). Habitat: Inside large crevices in rocks or other hard sub- strata, from just below low tide level to ca. 20 m, crawling free or byssally attached, generally isolated or in small numbers. Selected measurements (in millimeters, length x max- imum height from umbo to margin): Page 346 Guethary 8.6 x 4.0 Marseille 13.4 x 6.3 eo) SOD 9.2 x 4.9 9.2 x 4.3 Algarve 9.6 x 4.4 8.2 x 4.0 8.8 x 4.3 8.1 x 4.3 7.8 x 3.8 8.0 x 3.8 6.3 x 2.9 Corsica OW/EX: 353 Herm 12.4 x 5.3 bs) 6 PAR 10.8 x 5.2 10.6 x 5.1 Almeria 6.7 X 3.4 10.3 x 5.1 Remarks: The morphology and anatomy of this species have been described in detail by several authors, among them MITTRE (1847), PELSENEER (1911:44-45, pl. 16), and POPHAM (1940). BRUSINA (1866) distinguished Gale- omma pileum as being shorter, more oval, and more mark- edly depressed laterally. This description is here considered to fall within the variability of G. turtonz. Two specimens from Guethary, Bay of Biscay, have each been observed to host a dwarf individual attached to the ventral part of the mantle, near the edge of the valve. One of these has been sectioned (personal communication, G. Rodriguez, University of Oviedo). The large individual was a female. The small specimen has only a reduced foot and mantle, and a male gonad occupying its entire internal volume. The shells of the other pair were photographed under SEM (Figures 1-3). The large shell is 9 mm long and has a smooth protoconch consisting of hemispherical valves 310 um in diameter. These are separated from the teleoconch by a sharp boundary, and the radial ribs of the teleoconch start exactly from that boundary. The smaller attached shell is 740 um long, with a protoconch similar in size and shape to that of the larger shell. Its teleoconch is very small, with sculpture consisting only of irregular, coarse growth lines, and no radial ribs. A brooding specimen from Sagres, southern Portugal, was seen releasing spawn, eggs or small larvae less than 100 wm in size, in May 1988. The morphology of the larval shell, with recognizable protoconch-1 and proto- conch-2, and the abrupt protoconch-teleoconch boundary suggest that there is planktotrophic larval development. Specimens collected in Angola (Figures 4, 5) are sep- arated from the nearest northward locality (Ouaran, Sen- egal) by a large gap. The distribution of the species may be disjunct, like that of many West African bivalves (R. von Cosel, personal communication). Galeomma coalita Gofas, sp. nov. (Figures 6-8) Type material: Holotype (MNHN), live-taken specimen and attached allotype: Caotinha, under stone at low tide mark, leg. Gofas, December 1985. Paratypes (all leg. Gofas, 1983-1986, MNHN): An- The Veliger, Vol. 34, No. 4 gola—Bango, 10 km S Ambrizete, province of Zaire, 1 valve (Figure 6); Praia Sao Tiago, province of Bengo, 1 valve; Barra do Dande, province of Bengo, 1 juvenile valve; Sao Nicolau, province of Namibe, 1 live-taken specimen (left valve crushed), under stone at low tide mark. Type locality: Caotinha (12°36’S, 13°15’E), Benguela Province, Angola. Other material examined: Senegal—Baie de Gorée, south of Tacoma, 25 m, 1 valve (leg. Marche-Marchad, MNHN); SE of Gorée, in fine muddy sand, 17 m, 1 valve (/eg. von Cosel 24 March 1988, MNHN). Habitat: The living specimens were found under stones, byssally attached to the rock surface. Description: Shell 8-11 mm long, thin and fragile, equi- valve, slightly inequilateral with beaks anterior to the ver- tical midline. Outline oval-elongate with dorsal margin straight along ca. 4) of the total length, anterior and posterior margins well rounded, and ventral margin nearly straight beneath the umbos. Protoconch with hemispher- ical valves, 300 wm in diameter, smooth, demarcated from the teleoconch by a distinct line. Teleoconch with a retic- ulate external sculpture of radial riblets and concentric threads; the interspaces 2-3 times as broad as the riblets. Radial ribs divergent along the anterior and posterior slopes of the shell. Additional riblets added in the interspaces, and a few riblets terminating without reaching the margin of the shell. Shape laterally compressed, with valves almost closing ventrally. Hinge line smooth, interrupted under the umbo by a small resilifer, of different shape on the two valves. Left valve with a small vertical notch just beneath umbo and an oblique toothlike structure next to it posteriorly; right valve with a very oblique notch opposite to the toothlike structure of left valve, and hinge line abutting anteriorly to it with a small knob. Internal ligament short, in resilifer; external ligament thin, extending along hinge line. Inside of valves with a broad, irregular, entire pallial line merging into the muscle scars. Scar of anterior ad- ductor larger and closer to dorsal line than that of posterior adductor. Scar of posterior pedal retractor large, above the posterior adductor. Inner area beneath the umbo slightly granulated. Mantle (Figure 8) thin and translucent, covering outer two-thirds of shell with tiny (ca. 200 um) papillae scattered over surface. One short tentacle attached at each end of hinge line. Dwarf individual found attached by its foot to mantle of holotype, close to middle part of ventral margin: pro- toconch as above, teleoconch with leaf-shaped valves, gap- ing ventrally, pointed anteriorly and posteriorly, and with sculpture of coarse concentric growth lines only. Selected measurements (in millimeters, length