THE NAUTILUS Volume 101, Number 1 January 30, 1987 ISSS 0028-1344 A quarterly devoted to malacology. UBKkm FEB a 1987 Woods Hole, Mass. EDITOR-IN-CHIEF Dr. M. G. Harasewych Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC 20560 ASSOCIATE EDITOR Dr. R. Tucker Abbott American Malacologists, Inc. P.O. Box 2255 Melbourne, FL 32902 CONSULTING EDITORS Dr. William K. Emerson Department of Living Invertebrates The .American Museum of Natural History New York, NY 10024 Mr. Samuel L. H. Fuller 1053 Mapleton Avenue Suffield, CT 06078 Dr. Robert Hershler Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC 20560 Dr. Richard S. Houbrick Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC 20560 Mr, Richard I. Johnson Department of Mollusks Museum of Comparative Zoology Harvard University Cambridge, MA 02138 Dr. .'\urele La Rocque Department of Geology The Ohio State University C:oiumbus, OH 43210 Dr. James H. McLean Department of Malacology Los Angeles County Museum of Natural History 900 Exposition Boulevard Los Angeles, CA 90007 Dr. Arthur S. Merrill % Department of Mollusks Museum of Comparative Zoology Harvard University Cambridge, MA 02138 Dr. Donald R. Moore Division of Marine Geology and Geophysics Rosenstiel School of Marine and .Atmospheric Science University of Miami 4600 Rickenbacker Causeway Miami, FL 33149 Mr. Richard E. Petit P.O. Box 30 North Myrtle Beach, SC 29582 Dr. Edward J. Petuch Department of Geology Florida Atlantic University Boca Raton, FL 33431 Dr. G. Alan Solem Department of Invertebrates Field Museum of Natural History Chicago, IL 60605 Dr David H. Stansbery Museum of Zoology The Ohio State University C:olumbus, OH 43210 Dr. Ruth D. Turner Department of Mollusks Museum of C^omparative Zoology Harvard University C:ambridge. MA 02138 Dr. Geerat J. Vermeij Department of Biology University of Maryland College Park, MD 20740 Dr. Gilbert L. Voss Division of Biology and Living Resources Rosenstiel School of Marine and Atmospheric Science University of Miami 4600 Rickenbacker Causeway Miami, FL 33149 SUBSCRIPTION INFORMATION The subscription rate per volume is US $15.00 for individuals and US $25.00 for institutions. Postage outside the United States is an additional US $2.00 for surface and US $10.00 for air mail. All orders should be accompanied by payment and sent to: THE NAUTILUS, P.O. Box 3430, Silver Spring, MD 20901. Change of address: Please inform the publi.sher of your new address at least 6 weeks in advance. All communications should include both old and new addresses (with zip codes) and state the effective date. THE NAUTILUS (ISSN 0028- 1344) is published quarterly by Trophon Corporation, 363 Crescendo Way, Silver Spring, MD 20901. Second Class postage paid at Silver Spring, MD and additional mailing offices. POSTMASTER: Send address changes to: THE NAUTILUS P.O. Box 3430 Silver Spring, MD 20901 THE NAUTILUS Volume 101 1987 AUTHOR INDEX Abbott, R. T 101 Batie, R. E 186 Berg. C J , Jr 19 Boss. K, J 45, 151 Bltm.an. B 19 D'.-\ttilio. .V 162 Davis. L. E 93 Early, J. A. 19 Emerso.\. W K 194 Fairbanks. H. L 86 H.arasewych, M. G 3, 48, 166 Hershler. R 25, 133 Houbrick. R, S 9, 80. 101, 155 Knight, R. L 93 KooL, S. 117 Longley, G 133 Lowell, R. B 69 Marks, J. A 69 Martin, R. F 75 McLean, J. H Ill Merrill, .AS. 45 Mikkelsen. p. M 51 \1ikkelsen, p. S ■ 51 Myers, B. W 162 Petit, RE 48, 154 Petlch, E. J 200 Pip. E 33, 140 PooN. PA 88 QuiNN, J. F.. Jr .59, 111 Randall, C. W 75 Robertson, R 101 S,\GE, W E, III 194 Salnders. W. B 93, 188 Schmidt, J. E 182 Shasky. D, R 162 Theler, J. L 143 Thompson, F. G 25 ToLiN. W. A 182 TlRNER, R. D 19 \ krmeij, G. J 69 \\ alters. L. J 69 Ward, P. D 188 Zeto. M. .\ 182 NEW TAXA PROPOSED IN VOLUME 101 (1987) GASTROPODA Cataeginae McLean and Quinn, new subfamily (Trochidae) Ill Cataegis McLean and Quinn, new genus (Trochidae) 113 Cataegis loreuta McLean and Quiiui, new species (Trochidae) 113 Cataegis mcroghjpta McLean and Quinn, new species (Trochidae) 115 Cataegis celebescnsis McLean and Quinn, new species (Trochidae) 115 Hadroconus Quinn. new genus (Seguenziidae) 61 Rotcllcnzia Quinn, new genus (Seguenziidae) 64 Asthelijs Quinn, new genus (Seguenziidae) 66 Phreatodrobia coronae Hershler. new species (Hydrobiidae) 133 Ataxocerithitim eximium Houbrick, new species (Cerithiopsidae) 157 PhijUonotus eversoni D'AttiUo, Myers and Shasky. new species (Muricidae) 162 Ecphora hradleyae Petuch, new species (Thaididae) 204 Ecphora hertweckunim Petuch, new species (Thaididae) 204 Tractoliru germonae Harasewsch, new species (Volutidae) 3 BenthoLoliita claydoni Harasevv\ch, new species (Turbiiiellidae) 173 CanccUaria quasiUa Petil. new name (Cancellariidae) 154 Cancvllaria (Mcrica) laddi Pclil. ricu name (C^ancellariidae) 154 THEC7NAUTILUS Voltiiue 101. Number 1 Jamicny 30, 1987 ISSN 0028-1344 CONTENTS M. G. Harasewych Tractolira germonae, A new abyssal Antarctic volute 3 Richard S. Houbriek Anatomy of Alaba and Litiopa (Prosobranchia: Litiopidae): Systematic implications 9 Carl J. Berg, Jr., Seasonal recruitment of marine invertebrates to hard Bradford Butman, substrates on Georges Bank and the eastern continental Julie A. Early, and shelf of the United States 19 Ruth D. Turner Robert Hershler and North American Hydrobiidae (Gastropoda: Rissoacea): Fred G. Thompson Redescription and systematic relationships of Tryonia Stimpson, 1865 and Pyrgulopsis Call and Pilsbry, 1886 25 Eva Pip Ecological differentiation within the genus Helisoma (Gastropoda: Planorbidae) in central Canada 33 Kenneth J. Boss and The publication date of Solarium architae O. G. Costa 45 Arthur S. Merrill M. G. Harasewych and The status of Tritonium viridulum Fabricius, 1780 48 Richard E. Petit News and Notices 50 IJIariMBidB^UtaaHT i LIBRARY j FEB 11 19fiy 1 Woods Hole. Mass. With the completion of Volume 100 of THE NAUTILUS, one dedicated to "all the molluscan enthusiasts, both private conchoiogists and professional malacologists, who founded and carried on for the last 100 years America's oldest journal devoted exclusively to the study of mollusks," Dr. R. Tucker Abbott retired as Editor-in-Chief. Under his direction, first as co-editor (1958-69) then as editor (1970-86), THE NAUTILUS has prospered and grown for nearly three decades. During his tenure as editor of THE NAUTILUS, R. Tucker Abbott also founded and edited Indo- Pacific Molhtsca and Monographs of Marine Mollusca. In addition, Dr. Abbott has become the most prolific and widely published malacological author of his generation, having written many landmark books on .\merican and worldwide mollusks, several of which have been published in multiple editions, as well as a number of monographs and numerous research papers. Having ushered THE NAUTILUS into its second century of publication. Dr. Abbott will continue to serve as Associate Editor, but will devote more time to writing. Like preceding editors of THE NAUTILUS, Dr. Abbott has earned an eminent position in the history of American malacology. With a change in editorship, a number of other changes may be apparent, among them yet another change in journal size, a new cover and format, expanded instructions to authors, a larger panel of consulting editors, and a new publisher, Allen Press. For the new cover and format, we are greatly indebted to Hal Lewis Design, Inc. FinalK', THE NAUTILUS, which had been privately owned in its first century of publication, is now published b\ Trophon Corporation, a non-profit corporation established to publish works on mollusks. Despite these changes, the purpose of this publication, that of "giving information of \ital interest to the student of Mollusca", remains the same. As it begins its second century of service to the malacological community, THE NAL TILLS will continue to meet ever higher standards in the publication of papers on all aspects of the biolog\- and systematics of mollusks. M. G. Harasewych Editor THE NAUTILUS 101(l):3-8, 1987 Page 3 Tractolira germonae, A New Abyssal Antarctic Volute M. G. Harasewych Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA ABSTRACT Tractolira germonae, a new species of volute, is described from abyssal depths along the Scotia Arc, and assigned to the previously monotypic genus Tractolira on the basis of shell and radular morphology. Anatomical characters of this new species support the inclusion of Tractolira in the subfamily Odontocymbiolinae, and suggest a close relationship between the subfamilies Odontoc\mbiolinae and Zidoninae. INTRODUCTION The United States Antarctic Research Program (USARP) has been conducting research, including the samphng of Antarctic and Subantarctic biotas for nearly three decades. A study of the abyssal gastropods collected by USARP has uncovered a number of specimens of a new species of volute, apparently endemic to the perimeter of the Scotia Sea. This species described herein is as- signed to the previously monotypic genus Tractolira Dall, 1896. The inclusion of Tractolira in the subfamily Odontoc>mbiolinae by Weaver and duPont (1970:133) rested on the statement by Dall (1907:365) that the now lost radula of T. sparta Dall, 1896, the t\pe species from the abyssal zone off western Central America, "is marked by the same tusk-like cusps as are found in Miomelon", one of the two genera originally included in the subfam- ily. A description of the anatomy serves as the basis for a discussion of the phylogenetic affinities of Tractolira and Odontocymbiolinae. SYSTEMATICS Family Volutidae Rafinesque, 1815 Subfamily Odontocymbiolinae Clench and Turner, 1964 Genus Tractolira Dall, 1896 Tractolira gernwnae new species (figures 1-3, 5-13; table 1) Description: Shell (figures 1-3) to 60 mm, extremely thin, translucent, elongate, fusiform, eroded where not covered by periostracum (figures 5, 7). Protoconch badly eroded on all specimens, with vestiges of projecting cal- carella at ape.x. Shell with up to five moderately convex whorls. Suture impressed. Spiral sculpture of 60-80 fine threads on body whorl, 20-30 on preceding whorls, de- creasing in prominence with increase in shell size. Axial sculpture limited to fine growth striae. Aperture ovate. Outer lip smooth, slightK' flared in larger specimens. Inner lip smooth, with thin transparent inductura along parietal region. Columella smooth, with raised white si- phonal fold. Outer shell layer white to light tan, eroded areas of shell white, aperture white. Periostracum (fig- ure 5) thin, greenish brown. Inner shell surfaces smooth, continuous. Ultrastructure: Shell of three orthogonal layers of crossed lamellar crystals: outer layer 20 ^lm thick, with crystal faces perpendicular to growing edge; middle lay- er 120 nm thick, with cr\stal planes colabrally aligned; inner layer 12 yum thick, with crystal planes again per- pendicular to growing edge. X-ray diffraction analysis showed shell to be composed almost exclusively (> 99%) of aragonite, with no significant amounts of calcite or vaterite. External anatomy: Soft parts comprise three whorls, mantle cavity spans V2 whorl, kidney '/$ whorl, digestive gland two whorls. Foot (L/W = 1.5) broad anteriorly, tapering posteriorly, with deep propodial mucous gland (figure 9, pmg). Operculum absent. Animal yellowish tan, without visible color pattern in alcohol-preserved material. Sole of foot deeply glandular, producing co- pious mucus. Siphon (figure 9, s) muscular, free, about 1/5 shell length. Two ventral appendages, equal in length, extend from base of siphon (figure 9, sa), one on each side of left cephalic tentacle (figure 9, t). Head broad, with short tentacles on each side of hood that extends over rhynchostome. Outer edges of tentacles with broad semicircular projections. Eyes absent. Mantle cavity: Arrangement of mantle cavity organs similar to that of Alcithoe arabica as described by Pon- der (1970). Mantle edge thickened, muscular, smooth. Osphradiuin with 46 filaments below and 60 above os- phradeal ganglion. Ctenidium, of about 200 filaments, slightly narrower (0.9 x ) and about 1.4 times as long as osphradium. Hypobranchial gland deeply glandular, producing purple secretion. Pericardium forms left rear Page 4 THE NAUTILUS. Vol. 101, No. 1 igurcs 1-3. Tractulira gcrmomw new .species 1. Holotype, USNM 859076 2. Paratype 1, USNM 845611, both from Islas Orcada a. 38, east of Candlemas Island, South Sandwich Island's, in 2,740-2,757 m. 3. Paratype 5, USNM 845612, Islas Orcada sta 51, south of Candlemas Island, South Sandwich Islands, in 2,248-2,402 m. Figure 4. Traciolira sparta Dall, 1896 Holotype, USNM 122999, Albatross sta. 3360, Gulf of Panama, in 3,058 m, sand bottom. All figures 1.5 x. F] sta wall of mantle cavity, ventricle diameter 2.5 x auricle diameter. Alimentary system: Proboscis short, broati, pleurem- bolic, partially protruded in majority of specimens ex- amined (figure 9, pb). Proboscis retractor muscles at- tached to walls of cephalic hemocoel. Mouth (figures 9, 10, m) triangular. Buccal mass (figure 10, bm) muscular. Radular ribbon short (5-7 mm), uniserial with 48-56 teeth, each with three tusk-like cusps. Central cusps M G Harasewvch, 1987 Page 5 Figures 5-8. Tractolira germonae new species. 5. Periostracum, scale bar = 200 nm. Note erosion of shell where not covered by periostracum. 6. Shell ultrastructure, fracture surface parallel to growing edge, scale bar = 25 fim. 7. Eroded surface of shell, scale bar = 80 /im. 8. Radular ribbon, scale bar = 80 /im. shorter and narrower than outer cusps (figure 8). Acces- sory salivary glands (figure 10, asg) wrapped tightly around salivary glands (figure 10, sg). Ducts of accessory salivary glands join (figure 10, dasg) before entering buccal cavity ventrally. Ducts of salivary glands run along the esophagus, entering buccal cavity dorso-laterally. Valve of Leiblein (figure 10, vl) large, nearly spherical. Gland of Leiblein (figure 10, gl), long, tubular, highly convoluted, fills posterior % of cephalic hemocoel. Pos- terior esophagus (figure 10, pe) reflected dorsally before joining U-shaped stomach. Section of stomach anterior to single duct from digestive gland (figure 11, ddg) tu- bular, with longitudinal folds. Posterior to digestive gland duct, stomach forms caecum (figure 10, c), becoming transversely pleated before joining intestine (figure 10, int). Intestine with longitudinal folds, expands into pink rectum (figure 10, r), with jade green anal gland (figure 10, ag) along distal '/s of its length. Anus (figure 10, a) with muscular rim and ventral papilla. Female reproductive system: Ovary ascinous, whitish, on columellar side of digestive gland. Oviduct (figure Page 6 THE NAUTILUS, Vol. 101, No. 1 11 pmg 12 rmc asg Figures 9-13. Anatomical features of Tractolira germonae new species. All figures 3.0 x. 9. .interior view of animal. 10. Alimentary system, 11. Stomach, opened dorsally. 12. Female glandular oviduct. 13. Male pailial gonoduct. a. anus; ag, albumen gland; asg, accessory salivary gland; be, bursa copulatrix; bm, buccal mass; c, caecum; eg, capsule gland; co, connective tissue; dasg, duct accessory salivary gland; ddg, duct digestive gland; fo, female opening; gl, gland of Leiblein; ig, ingesting gland; int, intestine; m, mouth; od, oviduct; pap, papilla; pb, proboscis; pe, posterior esophagus; pen, penis; pmg, propodial mucous gland; pr, prostate gland; r, rectum; rg, rectal gland; rmc, rear mantle cavity; s, siphon; sa, siphonal appendage; sg, salivary gland; sto, stomach; t, tentacle; td, testicular duct; vd, vas deferens; vl, valve of Leiblein. 12, od), thin, leading to rear of mantle cavity and en- tering anterior ventral edge of albumen gland (figure 12, ag), which forms right wall of kidney Pailial oviduct is joined by the purplish ingesting gland (figure 12, ig) before expanding into capsule gland ( figure 12, eg). Bur- sa copulatrix (figure 12, be) forms blind muscular di- verticulum between female opening (figure 12, fo) and capside gland. Male reproductive system-. Testis yellowish tan, lines right side of digestive gland. Testicular duct tubular, passing along pericardium before entering mantle cav- M. G. Harasewych, 1987 Page 7 ity. Prostate gland (figure 13, pr) slit ventrally, spans posterior half of mantle cavity. Prostate and rectum sur- rounded by connective tissue (figure 13, co) to form cylindrical mass. Vas deferens (figure 13, vd) descends to mantle Door, forming groove w ith fused edges that runs to base of penis (figure 13, pen). Penis short, dor- soventrally flattened, reflected posteriorly, with terminal papilla (figure 13, pap). Penial duct as in Alcithoe ara- bica (Ponder, 1970: fig. 32). Kidney: Kidney similar to that of Alcithoe arabica (Ponder, 1970: fig. 33), consisting of nephridial gland adjacent to pericardium, heavily pleated dorsal area, and ventral area with seven large lamellae. Latter two areas each fed by branch of the renal vein. Kidney opening over renal vein on left side of kidne\'. Reno-pericardial opening at anterior upper left corner of kidney. Nervous system: Nervous system Type 2 (Ponder, 1970: 159), with supraesophageal and right pleural ganglia fused. Etymology: This species honors Mrs. Raye N. Germon, Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution, for her con- tributions to the study of Antarctic mollusks. Type locality: East of Candlemas Island, South Sand- wich Islands, 57°00.4'S, 27°10.1"W, in 2,740-2,757 m, Islas Orcada Cruise 575, sta. 38, May 22, 1975. Holotype: USNM 859076, 9, length 59.1 mm. Paratypes: Paratypes 1-4, USNM 845611, from the tvpe locality; paratvpes 5-10, USNM 845612, paratvpe'll, ANSP A 11540, paratvpe 12, BM(NH) 198141, 57°22.6'S, 26°34.0'W, in 2,248-2,402 m, May 26, 1975, IO-575, sta. 51; paratypes 13-16, USNM 845613, 57°39.0'S, 26°00.4'W, in 2,380-2,609 m. May 27, 1975, IO-575, sta. 54; paratvpes 17-19, USNM 845614, 56°29.5'S, 26°46,9'W, in 2,248-2,387 m. May 30, 1975, 10-575, sta. 63; paratypes 20-29, USNM 845615, paratypes 30-31, DMNH 169441, 56°03.5'S, 26°58.3'W, in 2,128-2,161 m, June 3, 1975, IO-575, 53°25.2'S, 45°17.0°W, in 2,632- 2,691 m, June 12, 1975, IO-575, sta. 104. Distribution: All live-collected specimens were taken off the South Sandwich Islands, with one record, based on shell fragments, from the Scotia Ridge. The con- firmed bathymetric range for T. germonae is 2,161- 2,740 m, with a mean station depth (n = 6) of 2,449 m. This species appears to be endemic to the Scotia Arc. Ecology: All specimens of this abyssal species were tak- en on mud bottoms. Upper whorls of even the smallest specimens are eroded. The periostracum protects the shell from dissolution (figure 5), as this species lives be- low the aragonite compensation depth (Morse & Berner, 1979). A radular ribbon belonging to a naticid of the genus Amauropsis (Powell, 1951: fig. J) was found in the stomach of a dissected specimen. Table 1. Tractolira germonae new species. Measurements of shell and radular characters. Linear measurements in mm. n = 10. Character .\ Range SD Shell length .50.0 35.9-59.2 6.9 Aperture length 27.0 21.4-30.1 3.2 Shell length Aperture length 0,540 0.503-0,586 0.028 Total # whorls 4,75 4.25-5.00 0.25 Spire angle .31,8° 28.8°-37.6° 2.8° Radular length 6.2 5,0-6.8 0 6 # Radular rows .52.4 48-56 2,7 Comparative remarks: Tractolira germonae differs from T. sparta Dall, its only living congener, in having a broader, less elongate shell with a proportionally larger aperture, in lacking axial ribs on the early whorls and in having broader, less pronounced spiral sculpture. Nei- ther preserved material of T. sparta nor the radula de- scribed by Dall are available, and anatomical compari- sons cannot be made, other than to note that the radula of T. germonae resembles that of Miomelon philip- piana (Dall, 1896) (Pilsbry & Olsson, 1954: pi. 3, fig. 9), therein agreeing with Dall's (1907:365) description of the radula of T. sparta. The holotype of Tractolira spar- ta was illustrated by Dall (1908). The specimen figured by Weaver and duPont (1970: pi. 56 G, H) as the ho- lotype is a paratype (USNM 123000) from Malpelo Is- land, Colombia. The holotype of T. sparta is figured herein (figure 4). DISCUSSION Clench and Turner (1964:170) erected the taxon Odon- tocymbiolinae, a replacement name for the subfamily Adelomeloninae Pilsbry and Olsson (1954), to include the South American genera Odontocymbiola and Miomelon. Although some species in these genera strongly resemble some members of the Zidoninae in shell form, Odontocymbiolinae can be readily identified by their characteristic radular teeth, which have "fang- like" denticles. Other characters that serve to differen- tiate the Odontocymbiolinae include the presence of the long, symmetrical siphonal appendages, tubular acces- sory salivary glands that are tightly wound around com- pact salivary glands, a vas deferens that forms a closed duct, a penis with closed duct and terminal papilla, and a stomach with a tubular anterior region. Although fig- ured (pi. 82, figure 36), the last feature was not discussed by Clench and Turner (1964). Weaver and duPont (1970) provisionally included the abyssal eastern Pacific genus Tractolira and the Australian genus Volutoconus in Odontocymbiolinae, largely on the basis of radular mor- phology. The inclusion of Tractolira in Odontocymbiolinae is further supported by features of the salivary glands, ac- cessory salivary glands, stomach, and male reproductive Pages THE NAUTILUS, Vol. 101, No. 1 system. Although fang-like cusps are present in Trac- tolira, they are not as elaborately modified as in some other members of the subfamily (Weaver & duPont, 1970: figure 27). The protoconch of Tractolira, with its pointed calcarella, more closely corresponds to that of Adelometon ancilla (Solander, 1786) (Clench & Turner, 1964: pi. 93), a member of the Zidoninae, than to those of Odontocymbiolinae (Clench & Turner, 1964: pi. 82, fig. 35). The penis of Tractolira has the duct and papilla of Odontocymbiolinae, but resembles that of Zidoninae in size and disposition. In view of the numerous similarities in anatomy and shell morphology between the Zidoninae and Odonto- cymbiolinae (Clench & Turner, 1964), and because the character states that have been used to distinguish the Odontocymbiolinae are clearly derived from homolo- gous features in the Zidoninae, it is suggested that these two subfamilies are sister groups, with the Odontocym- biolinae being derived from the Zidoninae, and that Tractolira is a primitive genus within the Odonto- cymbiolinae. Zoogeographic distributions of Recent species (Weaver & duPont, 1970) further suggest that the Zidoninae radiated in the Austral Province (Kauff- man, 1973) during the Cretaceous, while the geograph- ically more restricted Odontocymbiolinae evolved in the Weddellian Province (Zinsmeister, 1979, 1982) after the separation of New Zealand at the end of the Early Pa- leocene. Dall (1907:365) proposed "Valuta" alta Sowerby, 1844, from shallow water early Tertiary deposits of Chile, as an ancestor of Tractolira. It is here proposed that the genus Tractolira colonized the abyssal regions of the Peru Basin during the early Tertiary, and that speciation of T. germonae is due to vicariance resulting from the displacement of tectonic fragments from the Pacific hin- terland of the Andean-West Antarctic Cordillera into the southwestern Atlantic during the Cenozoic (Dalziel & Elliot, 1973). ACKNOWLEDGEMENTS The assistance of Mr. Victor Krantz with specimen pho- tography, Mrs. Susann Braden with scanning electron microscopy, and Mrs. Molly Kelly Ryan with illustration is gratefully acknowledged. I thank Dr. Thomas Waller for helpful discussions and comments on an earl\ draft of the manuscript. LITERATURE CITED Clench, W. J. and R. D. Turner, 1964. The subfamilies V'olu- tinae, Zidoninae, Odontocymbiolinae and Calliotectinae in the western Atlantic. Johnsonia 4(43):129-180, Dall, \\ . li 1896. Diagnoses of new species of mollusks from the west coast of America. Proceedings of the United States National Museum 18:7-20. Dall, W. H. 1907. A review of the American Volutidae. Smithsonian Miscellaneous Collections 48(.3):34 1-373. Dall, VV. H. 1908. Reports on the dredging operations off the west coast of Central .-America to the Galapagos, to the west coast of Mexico, and in the Gulf of C^alifornia, in the charge of Alexander .Agassiz, carried on by the U.S. Fish Commission steamer "Albatross during 1891, Lieut. Commander Z. L. Tanner, U.S.N., Commanding, XXXVIII. and Reports on the scientific results of the ex- pedition to the eastern tropical Pacific in charge of Alex- ander Agassiz, by the U.S. Fish Commission steamer "Al- batross", from October, 1904, to March, 190.5, Lieut. Commander L. M. Garrett, U.S.N., Commanding, XIV. Reports on the Mollusca and Brachiopoda. Bulletin of the Museum of Comparative Zoology 43(6):205-487, pis. 1- 22. Dalziel, I. W. D. and D. H. Elliot 1973 Evolution of the Scotia Arc and Antarctic Margin. In: Nairn, A. E. M. and F. G. Stehli (eds). The ocean basins and margins, vol. 1, The South .Atlantic. Plenum Press, New York, NY, p. 171- 245. Kauffman, E. G. 1973. Cretaceous Bivalvia. In: Hallam, A. (ed.). Atlas of palaeobiogeographv. Elsevier, .Amsterdam, p. 353-383. Morse, J. W. and R. C. Berner. 1979. Chemistry of calcium carbonate in the deep oceans. In: Jenne, E. A. (ed). Chemical modeling in aqueous systems. American Chem- ical Society Symposium Series 93, Washington, DC, p. 499-535, Pilsbry, H. A. and A. A. Olsson. 1954. Systems of the Volu- tidae, Bulletins of American Paleontologv •35(152):271- 306, Ponder, W. F, 1970, The morpholog\ of Alcithoe arabica (Gastropoda: Volutidae), Malacological Review 3:127-165. Powell, A. W. B. 1951. Antarctic and Subantarctic mollusca: Pelecypoda and Gastropoda. Discover\ Reports 2647-196, pis. .5-10. Sowerby, G, B, 1846. Descriptions of Tertiary fossil shells from South America, In: Darwin, C, Geological observa- tions on South America, being the third part of the geol- ogy of the voyage of the Beagle, under the command of Capt, Fitzroy, R.N. during the years 18:32 to 1836, Smith, Elder and Co., London, Appendix, p. 249-268, pis, 2-5, Weaver, C. S. and J. E. duPont. 1970. Living volutes. Dela- ware Museum of Natural History, Greenville, DE, 375 p. Zinsmeister, W, J 1979. Biogeographic significance of the Late Mesozoic and EarU Tertiar\ molluscan faunas of Seymour Island (Antarctic Peninsula) to the final breakup of Gondwanaland, In: Gra\, J, and .A, J, Bouchot (eds.) Historical biogeography, plate tectonics, and the changing environment. Oregon State Universit) Press, Corvallis, OR, p. 349-355, Zinsmeister, W. J. 1982. Late Cretaceous-Early Tertiary molluscan biogeography of the southern circum- Pacific. Journal of Paleontology 56(1 ):84-102. THE NAUTILUS 101(1):9-18, 1987 Page 9 Anatomy of Alaba and Litiopa (Prosobranchia: Litiopidae): Systematic Implications Richard S. Houbrick Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA ABSTRACT Anatomical study of Litiopa and Alaba shows that these taxa differ from other cerithiaceans by a significant number of syn- apomorphies. These two taxa have been variously assigned to the Planaxidae, Litiopidae, Diastomidae, Rissoidae, Cerithi- idae, and to a number of subfamilies of the latter family Both genera are highly adapted to algal habitats and have a meso- podial mucous gland on the sole of the foot that produces long, anchoring mucus threads preventing dislodgement from the algae. They share similar taenioglossate radulae; many-whorled, ribbed protoconchs; nearly identical pallial oviducts; egg masses; and planktotrophic larvae. Both genera stand apart from other cerithiacean groups in having long, tapered, epipodial tenta- cles. The morphological evidence points to a close relationship between the two taxa and also supports their inclusion in the family Litiopidae Fischer, 1885. INTRODUCTION The higher taxonomic assignment of many small species of cerithiacean snails is controversial and frustrating. Convergent shell characters and lack of anatomical knowledge about the various taxa have resulted in an unstable classification. Moreover, many of the published systematic opinions about genera and families of ceri- thiaceans are based on vague, equivocal, conchological characters. I have discussed the taxonomic problems of small, heterogeneous cerithiacean taxa elsewhere (Hou- brick, 1980:4-5, 1981:610-611). This paper deals with the anatomy of Litiopa Rang, 1829, Alaba H. and A. Adams, 1853, and several related taxa, and presents an- atomical data for their natural systeinatic arrangement. Litiopa, while usually assigned to the family Litiopidae, has been thought to be related to the Planaxidae, Ris- soidae, or Cerithiidae by various authors. Alaba has like- wise been referred to the Cerithiopsidae, Planaxidae, Dialidae, Litiopidae, Diastomatidae, Cerithiidae, and to a number of subfamilies of the latter family. Bandel (1984:55) has discussed the confusing literature regard- ing the placement of Alaba. The status of a few other genera such as Stijliferina A. Adams, I860, and Diffal- aba Iredale, 1936 remains uncertain. The genus Diala A. Adams, 1861 is frequently considered a close relative of both Alaba and Litiopa and has been grouped with them (A. Adams, 1862; Smith, 1875:538) or placed in its own family, Dialidae (Hornung & Mermoud, 1928). Dall (1889:258) suggested that Alaba was related to Bittium Gray and Diastoma Deshayes. Other workers, such as Wenz (1938) and Franc (1968), have included Finclla A. Adams, Alabina Dall, and Alaba with the Diasto- matidae. A summary of the various taxonomic alloca- tions of Alaba and Litiopa is presented in table 1. Most workers have referred the two taxa to the subfamily Litiopinae and placed this group under the Cerithiidae Bruguiere, 1789. MATERIALS AND METHODS Living specimens of Litiopa melanostoma Rang, 1829 and Alaba incerta (Orbignv, 1842) were studied at the Smithsonian Marine Station at Link Port, Ft. Pierce, Florida during January, Februar\, and April of 1986. Litiopa melanostoma was collected offshore on Sargas- sum weed. Alaba incerta was collected from intertidal marine grass beds in St. Lucie Inlet, Florida, and on shallow water grass beds around Peanut Island in Lake Worth, Riviera Beach, Florida. Living snails were main- tained in petri dishes of sea water and relaxed in a 10% MgCL solution for study under a binocular dissecting microscope. Snails were preserved in Bouin s seawater fixative, embedded in paraffin, sectioned at 7 ^m, and stained with Alcian blue-PAS and counterstained in he- matoxylin (Humason, 1962:269). Critical point dried an- imals extracted from shells, radular ribbons, and proto- conchs were examined under a Novascan-30 scanning electron microscope to determine inicroscopic anatom- ical features. Protoconchs of some Australaba and Fi- nella species were also compared with those of litiopids. MORPHOLOGY Shell morphology: Members of both genera are small, not exceeding 25 mm in length, and have moderately turreted, conical, thin, nearly transparent shells. The shell Page 10 THE NAUTILUS, Vol. 101, No. 1 Figures 1-3. Animal of Alaba incerta. 1. Operculum, showing sinuous attachment ridge, by transparency. 2. Ventral view, showing sole of foot and disposition of epipodial tentacles. 3. Side view of female, showing ciliated groove and ovipositor on right side of head-foot (bar = 1 mm), ag = albumen gland; eg = capsule gland; cgr = ciliated groove; cm = columellar muscle; ct = cephalic tentacle; dg = digestive gland; e = eye; et = epipodial tentacle; etl = epipodial tentacular lobe; k = kidney; m = mouth; me = mantle edge; mmg = mesopodial mucous gland; op = operculum; ov = ovary; ovp = ovipositor; pmg = propodial mucous gland; pt = propodial tentacle; r = rectum; sn = snout; sf = sole of foot. of Alaha (figure 11) differs from that of Litiopa (figure 9) in being longer and in having irregularly distributed, wide varices and a taller, more turreted apex. In Litiopa, the whorls are more inflated and fewer in number than in Alaba, and the shell is tan-yellow while that of Alaba is vitreous and white. Litiopa has a wider aperture and a weak tooth at the base of the columella. Both taxa have tiny brown subsutural spots and flammules, but Alaba also has weak, spiral bands of tan spots. Litiopa and Alaba have nearly identical protoconchs comprising 3.5-4 whorls (figures 8, 10). Protoconch 1 is smooth (pit- ted under high magnification) while protoconch II is sculptured with numerous axial riblets divided by a thin spiral thread from a band of subsutural plaits. Micro- scopic spiral lines lie between the axial riblets in Litiopa (figure 8). A good figure of Litiopa melanostoma and its protoconch has been given by Okutani et al. (1983: 24, figs. 1-5). Robertson (1971:5, pis. 2, 3) presented detailed figures of the protoconchs of Alaba incerta and Litiopa melanostoma. The periostraca of both taxa are thin and transparent. The ovate, paucispiral opercula are completely transparent and have eccentric nuclei in both taxa. Only the portions of the opercula beneath the nuclei are attached to the metapodia by fine sinuous ridges (figure 1). This opercular attachment scar is clear- ly depicted by Robertson (1971;pl. 4, fig. 16), who noted R. S. Houbrick, 1987 Page 1 1 the similarity of the opercula of both taxa. A ridge-hke attachment scar is also described for Alaba goniochila by Kosuge (1964:36, fig. 6). External anatomy: Litiopa and Alaba are very active snails and move about quickly in the algae or on the underside of the surface film of the water, on which they glide shell down by means of their long foot. E.\- ternally, Litiopa is yellow with a pale foot while Alaba has a whitish base color flecked with olive brown and red spots. The slender cephalic and pedal tentacles are striped with reddish brown in Alaba. A conspicuous fea- ture in both genera is the long, narrow, active foot which is used to climb about algal filaments and fronds. A very deep, anterior propodial mucous gland lies at the lead- ing edge of the sole (figures 2, 3, 7, 15, pmg) and a large, mesopodial mucous gland is centrally located at the pos- terior of the sole (figures 2, 3, 7, 12, 15, mmg). The propodial mucous gland produces a sheet of mucus that moves posteriorly along the sole of the foot. Scanning electron micrographs of critical point dried snails show that the sole of the foot is covered with long, dense, cilia (figure 17). The mesopodial mucous gland is defined by a slit-like groove (figures 2, 3, 7, 12, 15, mmg) that pro- duces a strong mucus thread attaching the snail to the substrate or surface film of the water. If accidentally pulled or dislodged from their algal habitat, litiopids cling to the mucus thread in spider-like fashion, em- ploying the foot and mouth to crawl back and reestab- lish themselves. The mucus thread is quite strong and tensile. The mesopodial mucous gland occurs in both genera, but is especially well-developed in the pelagic snail, Litiopa. Neither of these anatomical features was noted by Kosuge (1964), although he depicted a longi- tudinal groove on the sole. A. Adams (1862) was the first to note the mesopodial mucous gland in Alaba. but his comments on the gland and its use in the spinning of mucus threads have been overlooked by subsequent workers. He also remarked that Alaba was similar to Litiopa in this respect. A small, median, mesopodial mu- cous gland that opens by a short duct to the posterior portion of the sole also occurs in the Turritellidae (Ran- dies, 1900:57). Another conspicuous feature in litiopids, and espe- cially in Alaba, is the presence of long epipodial tenta- cles along the sides of the foot (figures 2, 3, 15, 16, et), as noted by A. Adams (1862). The leading edge of the propodium has a pair of small, short tentacles, one on each side (figures 2, 3, pt). A lobe of epipodial tissue runs along the postero-lateral part of the metapodium, adjacent to the edge of the sole and supports the epi- podial tentacles and operculum (figure 2, etl). The major epipodial tentacles are long and tapered. A pair occurs on the left side of the foot and a single one is on the right side. A single tentacle is also at the posterior of the foot. Other smaller tentacles flank the major tentacles. When Alaba is viewed dorsally, the long right epipodial tentacle emerges from the exhalant siphon. Epipodial and cephalic tentacles have circular ridges along their lengths (figures 15, 16, et, ct). These ridges are not seen osb Figures J-, 5. Litiopid pallia! oviducts (distal end on left; bar = 0.3 mm). 4-. Litiopa melanostoma. 5. Alaba incerta (dotted lines 1 and 2 represent cuts corresponding to diagram- matic cross sections 1 and 2). acg = anterior ciliated groove; ag = albumen gland; eg = capsule gland; 11 = lateral lamina; ml = medial lamina; odg = oviductal groove; osb = opening to spermatophore bursa; osr = opening to seminal receptacle; sb = spermatophore bursa; sg = sperm groove; sr = seminal receptacle on living snails and may be the result of contraction of the tentacles. A. Adams (1862) described a pair of epi- podial tentacles on each side of the foot and a posterior pair in Alaba picta A. Adams, 1861. Kosuge (1964:36, figs. 1, 2) illustrated slender epipodial tentacles extend- ing well beyond the shell margin of Alaba goniochila. In Litiopa, the epipodial tentacles are much shorter and less conspicuous. The small head has a moderately extensible bilobed snout and a pair of long, tapered cephalic tentacles (fig- ures 2, 3, 6, 15, ct) that are extremely retractile and touch the substrate alternately while the snail is crawl- ing. The black e\es are surrounded by yellow pigment and located on the outer edge of the tentacular peduncle (figures 2, 3, e). The eyes are tiny and the tentacular bases have no peduncular bulge in Litiopa. The mantle edge of litiopids is smooth and bifurcate (figures 3, 15, me). Females have a ciliated groove (figures 3, 15, cgr) that emerges from the distal pallial oviduct, runs down the right side of the head-foot, and ends at the foot edge Page 12 THE NAUTILUS, Vol. 101, No. 1 -V rt'\. ^■^ -^ vl^lw ■xj i^x.l'myng Figure 6. Litiopa melanostoma and egg mass on Sargassum leaf (ct = cephalic tentacle; em = egg mass). Figure 7. Sagittal section through foot of Alaba incerta, showing operculum (op), mesopodial mucous gland (mmg), duct opening (Immg), and propodial mucous gland (pmg) (bar = 0.5 mm). Figure 8. Protoconch of Litiopa melanostoma, showing sinusigeral notch (bar = 80 /jm). Figure 9. .\dult shell of Litiopa melamistoma from off Ft. Pierce, Florida (length 7 mm). Figure 10. Protoconch of Alaba incerta, showing sinusigeral notch (bar = 80 ;uni). Figure II. Adult shell of Alaha incerta from St. Lucie Inlet, Florida (length 15 mm). Figure 12. Transverse section of Alaha incerta showing buccal mass (bm), foot (f), large mesopodial mucous gland (mmg), and lumen of duct (Immg) (bar = 0.5 mm) Figure 13. Radula of Litiopa melanostoma (bar = 20 ^lm). Figure 14. Details of rachidian, lateral, and marginal teeth of Litiopa melanostoma (bar = 16 Mni). R. S. Houbrick, 1987 Page 13 adjacent to the sole, where a fleshy glandular pad, the ovipositor (figure 3, ovp), is situated. The ovipositor is especially well-developed in Litiopa. Okutani et al. (1983:24, fig. 6) depicted the groove but not the ovipos- itor. The coils of the body whorl comprise the digestive gland, gonad, stomach, and kidney and are typically cerithioid in groundplan. Mantle cavity organs: Litiopid snails have a deep man- tle cavity dominated by a large ctenidium. A ridge-like monopectinate osphradium extends the full length of the ctenidium. Ctenidial filaments are long, tapered, tri- angular, and have many long cilia. Similar observations were made by Kosuge (1964:34) on Alaba goniochila. The narrow hypobranchial gland is thick, and in Alaba secretes an iridescent green substance when the snail is injured or irritated. The rectum is thin walled and pro- duces large ovoid fecal pellets that are tapered at one end. The glandular pallial gonoducts are large and thick in females but small and thin in males. Alimentary tract: The buccal mass of litiopids is large in relation to the snout size and has a pair of semicircular jaws. The radular ribbon of Alaba comprises 35-40 rows of teeth (n = 6) and is about one-fourth the shell length. The large buccal mass of Alaba was also noted by Kosuge (1964:34). The radulae of Alaba (figures 18-20) and Litiopa (figures 13, 14) are taenioglossate (2-l-H-H-l -1-2) and typically cerithioid, closely resem- bling the radulae of Cerithiidae in overall morphology. The rachidian tooth of Alaba (figure 19, r) is wider than long, has a straight anterior front, and an hourglass- shaped basal plate with a prominent central triangular buttress. This hourglass shape is also found in some gen- era and species of the Cerithiidae (Houbrick, 1980). The cutting edge of the rachidian has a sharply pointed cen- tral cusp flanked on each side by a pair of smaller den- ticles. The lateral tooth (figure 19, 1) is trapezoidal and has a basal plate with a long lateral basal extension and a strong, ventral, inner buttress. The cutting edge has a long central cusp, one inner denticle, with two outer denticles in Alaba (figure 19, 1), and two to four in Li- tiopa (figure 13). The marginal teeth of both genera (figures 13, 14, 18-20) are equal in length, scythe-shaped, and have cusped, spoon-like tips. The inner marginal tooth is about twice as broad as the outer and has two inner denticles, a long terminal cusp, and one outer den- ticle. The narrow outer marginal has 4-5 inner denticles in Alaba (figure 20), 8-9 in Litiopa (figure 13), a long terminal cusp, and a smooth outer edge. The radula of Alaba incerta has been described and figured in detail by Bandel (1984:39-40, fig. 71, pi. 4, figs. 1, 9). The mouth (figures 2, 15, m) and oral cavity are large and manipulate long strands of filamentous algae in Ala- ba and large Sargassum particles in Litiopa. The radula of Alaba goniochila is very similar to that of Alaba in- certa (Kosuge, 1964:36, figs. 7-10). Litiopids have a pair of tubular, uncoiled salivary glands that originate well behind the nerve ring and pass through it before emptying into the buccal cavity. Sal- ivary gland tubes are thicker in Litiopa than in Alaba. A large esophageal gland, formed by outpocketing of the lateral walls of the midesophagus, is present in Li- tiopa. This was also found in Alaba incerta and was noted by Kosuge (1964:34) in Alaba goniochila. The stomach of litiopids has a large central ridge, a gastric shield, and a short style sac. Although not seen in dis- sections, histological sections show that a crystalline style is present. The stomach of Alaba goniochila has been depicted by Kosuge (1964:36, fig. 5), and is similar to Alaba incerta. Sections show that the major typhlosole extends well into the proximal intestine. Reproductive tract: Litiopa and Alaba are typically cerithiacean in having open gonoducts and aphallate males. The pallial oviducts of both taxa consist of a thick- walled, slit tube attached along its dorsal side to the mantle wall (figures 4, 5). It comprises two laminae, a lateral one attached along its width to the mantle wall (figures 4, 5, II) and a medial, free lamina (figures 4, 5, ml). Along the longitudinal base of the laminae is the oviductal groove, which is wide and shallow (figures 4, 5, odg). The bulk of the pallial oviduct is dominated by a large swollen, proximal albumen gland (figure 5, ag) and by the adjacent distal capsule gland (figures 4, 5, eg). These glands have a mucus-like consistency and quickly swell with water when cut or injured. The al- bumen gland is more opaque than the capsule gland and stains a deep blue in section. The free medial lamina has a sperm groove along its median edge (figures 4, 5, sg) that enters into a small, proximal bursa (figures 4, 5, sb). In Litiopa. the bursa leads into a small pouch that appears to have a tiny opening on the inner side of the medial lamina (figure 4, osr). In the lateral lamina, im- mediately adjacent to this opening, is a pit-shaped pouch that is probably the seminal receptacle (figure 4, sr). The seminal receptacle is a round, deep chamber in Litiopa (figure 5, sr) while it is a compact pouch in Alaba. Eggs and larvae: The egg masses of Litiopa and Alaba are similar, forming flattened, gelatinous, clockwise spi- rals comprising one to four tight turns. Spawn masses of Alaba vary in size but average about 4.8 mm in diameter (n = 6). Unwound, an egg mass of this dimension com- prises a ribbon 18.5 mm long and 0.35 mm wide. A ribbon has 2-3 layers of very small eggs, about six across the ribbon width, and contains about 4,800 eggs. Each egg is 60 |im in diameter and is enclosed in a clear hyaline capsule about 80 ^im in diameter. This, in turn, is enclosed in an irregularly shaped gelatinous chamber about 0.13 mm across. The jelly chambers are covered in a gelatinous sheet forming a ribbon which is wound into a spiral which slightly overlaps the previous spirals. Jelly chambers and their enclosed eggs are tightly packed in the central region of the ribbon. The egg mass of Litiopa is deposited on Sargassum fronds (figure 6, em) and is similar to but smaller than that of Alaba. mea- suring about 2.5 mm in diameter and having fewer, broader spirals. Page 14 THE NAUTILUS, Vol. 101, No. 1 Egg masses of Alaba picta have been depicted by Habe (1960:122, fig. 4; cited as Australaba picta), Amio (1963:306, fig. 26), and Bandel (1976:262). Their figures conform witfi observations of Alaba incerta spawn. The egg mass of Litiopa has been poorly figured by Lebour (1945:467-468, fig. 8a) who described it as a flat circular mass. She did not note the spiral arrangement of the jelly ribbon. Development is rapid in both genera, the trochophore stage being attained in 2 days and early veliger stages within 3 days. Hatching takes place in about 6 days and is preceded by disintegration of the egg mass. Freed veligers are active swimmers and have a large bilobed velum with long cilia and a transparent shell. Lebour (1945:467, fig. 8c) depicted velar lobes of very unequal size in Litiopa and stated that it is one of the commonest veligers in open water plankton. The larval shell of Ala- ba has a reddish brown columella. Bandel's (1976:262) observations on Alaba from Santa Marta, Colombia, are essentially in agreement with mine. He noted that it takes a female about 90 minutes to produce a 2 cm long ribbon. The many-whorled, sculptured protoconchs with deep sinusigeral notches (figure 10) seen on the apex of adult snails of both taxa indicate a long planktotrophic phase before settlement. The protoconchs of Litiopa and Ala- ba are nearly identical in having many axial riblets. The protoconch of Litiopa has microscopic spiral lines be- tween the riblets and comprises about five sculptured whorls (figure 8) while in Alaba, there are only three whorls (figure 10). The larger protoconch of Litiopa in- dicates a long planktonic phase that is reflected in the pan-tropical distribution of this pelagic species. Robert- son (1971:5) noted the close resemblance between the protoconchs of Litiopa and Alaba and pointed out that full grown larval shells of Litiopa are larger than those of Alaba. He also noted the spiral lines ("crests") be- tween the axial ribs on Litiopa protoconchs. The litiopid protoconch is distinctive among cerithiaceans and ap- pears to be a good familial taxonomic character. Nervous system: Litiopids have an epiathroid nervous system. A statocyst occurs on the posterior of each pedal ganglion. The cerebral ganglia are joined by a very short commissure and the pleural ganglia are closely joined to the cerebrals. The subesophageal ganglion, although completely separated from the left pleural ganglion, is only separated from it by a very short connective. Zygo- neury does not occur. The supraesophageal ganglion is embedded in the left wall of the cephalic cavity. The RPG ratio (Davis et al., 1976:263) was 0.43 (n = 2) in Litiopa, indicating a tightly organized nerve ring. This is the lowest ratio observed among the Cerithiacea, but the low value may be a reflection of the small body size of litiopids, and its significance is questionable. SYSTEMATIC CONCLUSIONS Below is a family diagnosis and synonymies suggested for the genera Litiopa and Alaba. The synonymy for Alaba is tentative and needs confirmation by careful conchological and anatomical examination of the type- species of each taxon. Family Litiopidae Fischer, 1885 Diagnosis: Shell small, thin, having weak, shallow an- terior canal and protoconch sculptured with numerous axial riblets and subsutural plaits. Animal with epipodial tentacles, smooth mantle edge, mesopodial mucus gland, ridge-like osphradium, large esophageal gland, short sperm gutter, and seminal receptacle in lateral lamina of pallial oviduct. Genus Litiopa Rang Diagnosis: Shell moderately turreted, yellow-brown in color, with inflated, weakly sculptured whorls and ovate aperture with weak tooth at base of columella. Proto- conch sculptured with microscopic spiral lines between axial riblets. Animal yellow with well-developed ovipos- itor on right side of foot in females. Seminal receptacle a deep round chamber in posterior lateral lamina of pallial oviduct. Litiopa Rang, 1829:306. Type-species: Litiopa melanostoma Rang, 1829, by SD, Nevill, 1884. Bombijxintis Belanger in Lesson, 1835:32. T\pe-species: Litio- pa melanostoma Rang, 1829, bv OD. Bombycinus (emend, pro Bombyxinus Belanger, 1835) Agas- siz, 1846:104. Genus Alaba H. and A. Adams Diagnosis: Shell \itreous, white, weakly sculptured, with quadrangular aperture and very weak anterior canal; thick varices present on several whorls. Protoconch with numerous axial riblets. Seminal receptacle a compact pouch in posterior lateral lamina of pallial oviduct. Alaba H. and A. Adams, 1853:241. Tvpe-species: Rissoa me- laneura C. B. Adams, 1850, by SD (Nevill, 1885). Gihhorissoa Cossmann in Sacco, 1895:34. Type-species: ,Bu/i- mu.'i costcllala Grateloupe, 1828, by OD. Diffalaha Iredale, 1936:290. Tvpe-species: Diff alaba opiniosa Iredale, 1936, bv OD. Figures 15-20. Alaba incerta, animal and radula. 15. Critical point dried head-foot, showing sole and mucous glands, ct = cephalic tentacle; et = epipodial tentacle; cgr = ciliated groove; m = mouth; me = mantle edge; mmg = mesopodial mucous gland; pmg = propodial mucous gland (bar = 240 urn). 16. Detail of epipodial tentacles on critical point dried snail, et = epipodial tentacle (bar = 40 urn). 17. Dense cilia on sole of foot (bar = 4 ^m) 18. l?adula ribbon with marginal teeth spread back (bar = 40 ^m). 19. Detail of rachidian (r) and lateral (1) teeth (bar = 20 ^m) 20. Inner and outer marginal teeth (bar = 20 /um). R. S. Houbrick, 1987 Page 15 Page 16 THE NAUTILUS, Vol, 101, No. 1 Table 1. Taxononiic allocations given to Litiopa and Alaba. Genus SubfamiU FamiK Citation Litiopa Alaba Litiopinae Litiopinae Litiopinae Litiopinae Litiopinae Litiopinae Litiopinae Litiopinae Litiopinae Litiopinae Diastominae Cerithiopsinae Planaxidae Litiopidae Planaxidae Cerithiidae Cerithiidae Cerithiidae Cerithiidae Cerithiidae Litiopidae Planaxidae Cerithiopsidae Cerithiidae Cerithiidae Cerithiidae Dialidae Cerithiidae Cerithiidae Diastomidae Rissoidae Tryon (1882:246-247) Fischer (1887:718-719) Cossmann (1906:196-197) Thiele (1929:210-211) Wenz (1938:753) Franc (1968:281) Keen (1971:415-416) Abbott (1974:108) Iredale and McMichael (1962:43) Tryon (1882:246-247) H. and A. Adams (1853:239) E. A. Smith (1875:537) Thiele (1929:210-211) Wenz (1938:753) Iredale and McMichael (1962:43) Keen (1971:415-416) Abbott (1974:108) Kilburn and Rippey (1982:537) Laseron (1956:459) Obstopalia Iredale, 1936:299. Tvpe-species: Obstopalia lixa Iredale, 1936, by OD. Australaba Laseron, 1956:459. Type-species: Australaba bo- wenensis Laseron, 1956, by OD. Stijliferina A. Adams, 1860:.335. Type-species: Styliferina or- thochila A. Adams, 1860, by OD. Dialessa Iredale, 1955:81. Tvpe-species: Alaba transhicida Hedley, 1906, by OD. DISCUSSION No comprehensive anatomical studies of Litiopa or Ala- ba have previously been made. The earliest descriptions of the superficial anatomy and habits of Alaba were by A. Adams (1862), who described the animal of Alaba picta, a Japanese species living in shallow water Zostera beds. Adams (1862) pointed out the unusual features, such as epipodial tentacles and the mesopodial mucous gland, and noted that Litiopa shared these characters. He considered Diala and Styliferina as subgenera of Alaba and grouped all three in the family Litiopidae. His paper has been overlooked by subsequent workers. The genus Styliferina was originally described by A. Adams (1860:335), who later considered it a subgenus of Alaba A. Adams, 1862. There are two short recent papers on the anatomy of litiopids; one by Kosuge (1964) on Alaba goniochila, and a few brief notes on Litiopa melanostonm In Okutani et al. (1983). Ponder (1985:104) has noted that in Ko- suge's (1964) paper, Alaba goniochila is incorrectly cited as Diala goniochila, and likely to be overlooked in the literature for this reason. Furthermore, this paper ma\ mislead others to include the genus Diala with the Li- tiopidae. There can be no doubt that the species show n by Kosuge (1964) is an Alaba and not a Diala, for his description and figures unequivocally depict epipodial tentacles. I was previously misled by this paper when I incorrectly stated that Diala snails have epipodial ten- tacles (Houbrick, 1980:4). Living Diala species exam- ined in Queensland, Australia, did not have epipodial tentacles. It is thus clear that Diala is not closely related to Litiopa or Alaba and should not be referred to the Litiopidae. In the brief paper by Okutani et al. (1983) on Litiopa, only a radular drawing and a sketch of the head-foot were presented. The authors did not note the epipodial tentacles or the metapodial mucous gland, and incorrectly stated that there was no modification for pe- lagic life. Although only two genera are now unequivocally in- cluded in Litiopidae, other species and genera of small cerithiaceans may prove to be members of this group when their anatomy is better studied. The type of Fi- nella xanthacme (Melvill, 1904) [= Obtortio] has a pro- toconch like that of Litiopa, but no epipodial tentacles (Ponder, personal communication). Ponder (1967:197, pi. 10, figs. 7-9) has depicted the radula and operculum of Alaba (Dialessa) transhicida (Hedle\), strongly sug- gesting that the subgenus Dialessa is a litiopid. He later considered Dialessa to be a litiopid (Ponder, 1985:104) and has stated that Dialessa has an AlabaAike animal (Ponder, personal communication). Much of the anatomy of litiopids is similar to that of the cerithiids. The long extensible foot observed in li- tiopids also occurs in Bittium species from similar algal habitats. The ovate, paucispiral operculum w ith eccen- tric nucleus is also like that of Cerithium species. The ciliated groove and ovipositor on the right of the foot of females occur in Cerithiidae, in the genera Cerithium, Bittium (Marcus & Marcus, 1964:507), and Rhinoclavis (personal observation); in Potamididae. in Batillaria (personal observation) and Cerithidea (Houbrick, 1984: 3); and in the Modulidae and Thiaridae (Houbrick, 1984: 10). The large esophageal gland is also present in most members of the Cerithiidae (Houbrick, 1985:29) and R. S. Houbrick, 1987 Page 1' Modulidae (Houbrick, 1980:126). Litiopids, however, differ from members of the Cerithiidae in having a smooth mantle edge and in lacking a bipectinate os- phradium. Bandel {1984:55). on the basis of radular con- figuration alone, erroneous!) placed Alaba close to Cer- ithium. However, a number of significant, apomorphic, anatomical characters separate litiopids from other cer- ithiacean families and define them as a unique group that should be gi\en familial recognition. These include: 1) a median posterior, metapodial mucous gland that produces a strong mucus thread, anchoring the snail to its algal habitat [a mesopodial mucous gland also exists in the Turritellidae (Randies, 1900:57), but does not pro- duce a mucus thread and is probably a convergence]; 2) location of the seminal receptacle in the lateral lamina of the pallial oviduct; 3) an extremely short, distal sperm gutter in the medial lamina of the pallial oviduct; 4) long, retractile epipodial tentacles along the sides and posterior of the foot; and 5) an unusual protoconch sculptured with numerous axial riblets and subsutural plaits. Other distinguishing characters are: 1) a very deep propodial cleft into which the anterior mucous gland empties; 2) extremely long, slender cephalic tentacles; 3) a long extensible, narrow foot; 4) an operculum with a narrow spiral ridge on the attached surface; 5) an hourglass-shaped rachidian tooth with a strong trian- gular buttress; 6) large, swollen albumen and capsule glands in the pallial oviduct; and 7) mound-shaped egg masses comprised of tightly coiled jelly ribbons. The hypothesis that Litiopa and Alaba are closely re- lated had been previously suggested by A. Adams (1862) and Robertson (1971). Anatomical, radular, and con- chological e\idence resulting from this stud\' supports this hypothesis. The two genera are herein allocated to the family Litiopidae, as defined by the shared, derived characters described above. ACKNOWLEDGEMENTS Much of this work was supported by a grant from the Smithsonian's Marine Station at Link Port, Florida. I thank the following station staff for their help in this project: Hugh Reichart for assistance with photography, Woody Lee for histology, Julie Piraino for help on the SEM, and June Jones for computer assistance. This is Smithsonian Marine Station Contribution 172. I also thank Ms. Diane Bohmhauer of the National Museum of Natural History, Smithsonian Institution, for assis- tance with histology and proofreading the manuscript. Dr. Robert Hershler, National Museum of Natural His- tory, Smithsonian Institution, criticalh reviewed the manuscript. LITERATURE CITED Abbott, R. T. 1974 American seashells, 2nd ed. New York, 663 p., 24 pis. Adams, A. 1860. On some new genera and species of Mol- lusca from Japan. Annals and Magazine of Natural His- tory 6:331-;3.37. Adams, A. 1861. On some new genera and species of Mol- iusca from the north of China and Japan. Annals and Magazine of Natural History, series 3, 8:239-246. Adams, A. 1862. On the animal and affinities of the genus Alaba with a review of the known species, and descrip- tions of some new species. Annals and Magazine of Nat- ural History 1862:1-7. Adams, H. and A. Adams. 1853-58 The genera of Recent Mollusca, 3 vols., 389 p.. 138 pis, .4gassiz, J, L. R. 1846. Nomenclatoris Zoologici Index Univ- ersalis. Jent et Gassmann, Soloduri, 393 p Amio, M. 1963. A comparative embryology of marine gas- tropods, with ecological considerations. Journal of the Shi- monosseki University of Fisheries 12(2-3):229-358. Bandel, K. 1976. Observations on spawn, embryonic devel- opment and ecology of some Caribbean lower Mesogas- tropoda (Mollusca). The Veliger 18(3):249-271, 25 figs. Bandel, K. 1984 The radulae of Caribbean and other Me- sogastropoda and Neogastropoda. Zoologische Verhande- lingen No. 214:188 p., 22 pis. Cossmann, M 1906. Essais de paleoconchologie comparee. vol. 7. Paris, 261 p., 14 pis. Dall, W. H. 1889 Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mex- ico (1887-78) and in the Caribbean Sea (1879-80), by the U.S. Coast Survey Steamer 'Blake', Lieut-Commander C D. Sigsbee, U.S.N,, and Commander J. R. Bartlett. U.S.N., commanding. 29, Report on the Mollusca. Part 2, Gastrop- oda and Scaphopoda. Bulletin of the Museum of Com- parative Zoology 18:492 p., 40 pis. Davis, G. M., V. Kitikoon, and P. Temcharoen. 1976. Mono- graph on " Lithoghjphopsis" aperta, the snail host of Me- kong River schistosomiasis. Malacologia 15(2):241-287, 22 figs. Fischer, P. 1880-87. Manuel de conchyliologie et de paleon- tologie conchyliologique. Paris, 1369 p., 23 pis., 1158 figs. Franc, .\, 1968. Classe des Gasteropodes (Gastropoda Cuvier, 1798). In: Grasse (ed). Traite de zoologie. anatomic, sys- tematique biologic, 5 (Mollusques Gasteropodes et Sca- phopodes. III). Paris, 1083 p. Grateloupe, J. P. S. de. 1828. Tableaux des coquilles fossiles qu'on recontre dans les terrains calcaires tertiares (faluns) des environs de Dax, dans le departement des Landes. Bulletin de la Societe Linneenne d Histoire Naturelle, Bordeaux 2(9):72-109. Habe, T. 1960. Egg masses and egg capsules of some Jap- anese marine prosobranchiate gastropod (sic). Bulletin of the Marine Biological Station of Asamushi 10(2):121-126. II figs. Hedley, C. 1906, Studies on Australian Mollusca, Proceed- ings of the Linnean Society of New South Wales 30:522. Hornung, A. and G, Mermoud. 1928. Mollusques de la Mer Rouge recueilles par A. Issel faisant partie des collections du Musee Civique d Histoire Naturelle de Genes. Cinqu- ieme et derniere partie, Pleurotomides et Mitrides .\p- pendice. Litiopides (p 115-118) Annali del Museo Civico di Storia Naturale di Genova 53:108-121, 3 figs. Houbrick, R. S. 1980. Review of the deep-sea genus Argy- ropeza (Gastropoda: Prosobranehia: Cerithiidae). Smith- sonian Contributions to Zoology No. 321:30 p., 12 figs. Houbrick, R, S, 1981. Anatomy of Diastoma melanoides (Reexe, 1849) with remarks on the systematic position of the family Diastomatidae (Prosobranehia: Gastropoda). Proceedings of the Biological Society of Washington 94(2): 598-621. " Page 18 THE NAUTILUS, Vol. 101, No. 1 Houbric'k, R. S. 1984. Revision of higher taxa in genus Cer- ithidea (Mesogastropoda: Potamididae) based on compar- ative morphology and biological data. American Mala- cological Bulletin 2:1-20, 5 figs. Houbrick, R. S. 1985. Genus Chjpeomorus Jousseaume (Cer- ithiidae: Prosobranchia), Smithsonian Contributions to Zo- ology No. 403:131 p., 62 figs. Humason, G. L. 1962. Animal tissue techniques. San Fran- cisco, 468 p. Iredale, T. 1936. Australian molluscan notes. No. 2. Records of the Australian Museum 19:267-340, pis. 20-24. Iredale, T. 1955. Proceedings of the Royal Society of New South Wales 1953-54:81. Iredale, T. and D. F. McMichael. 1962. A reference list of the marine Mollusca of New South Wales. The Australian Museum, Sydney, Memoir 11109 p. Keen, A. M. 1971. Sea shells of tropical West America, 2nd ed. Stanford University Press, Stanford, 1064 p., 22 pis. Kilburn, R. N. and E. Rippey. 1982. Sea shells of southern Africa. Macmillan, Johannesburg, 249 p., 46 pis. Kosuge, S. 1964. Anatomical study of Diala goniochilia (A. Adams) (Gastropoda). Bulletin of the National Science Museum 7(l):33-36, 10 figs. Laseron, C. F. 1956. The families Rissoinidae and Rissoidae (Mollusca) from the Solanderian and Dampierian zoogeo- graphical provinces. Australian Journal of Marine and Freshwater Research 7(3):384-487, 228 figs. Lebour, M. V. 1945. The eggs and larvae of some proso- branchs from Bermuda. Proceedings of the Zoological So- ciety of London 114:426-489. Lesson, R. P. 1835. Illustrations de zoologie (20) Appendi.x, 14, no pagination. Marcus, E. and E. Marcus. 1964. On Cerithium airatum (Born, 1778) (Gastropoda: Prosobranchia). Bulletin of Ma- rine Science of the Gulf and Caribbean 14(3):494-510. Melvill, J C. 1904. Descriptions of tvvent\-three species of Gastropoda from the Persian Gulf, Gulf of Oman and Arabian Sea, dredged by Mr. F. W. Townsend of the Indo-European Telegraph Service, in 1903. Proceedings of the Malacological Society of London 6(l):51-60, 5 pis.; 158-169, pi. 10. Nevill, G. 1885. Hand list of Mollusca in the Indian Museum, Calcutta. Part 2, Gastropoda. Prosobranchia-Neurobran- chia (cont'd). Calcutta, 306 p. Okutani, T., T. Habe, and K, Hasegawa. 1983. An observa- tion on Litiopa melanostoma. Chiribotan 14(2):23-25. Ponder, W. F. 1967, The classification of the Rissoidae and Orbitestellidae with descriptions of some new taxa. Trans- actions of the Royal Societv of New Zealand 9(17):193- 224, 13 pis. Ponder, W. F. 1985. A review of the genera of Rissoidae (Mollusca: Mesogastropoda: Rissoacea), Records of the Australian Museum (1984), Supplement 4:221 p., 1.53 figs. Randies, W. B. 1900. On the anatomy of Turritella com- munis, Risso. Proceedings of the Malacological Societv of London 4:56-65, pi. 6. Rang, P. S. 1829. Notice sur le Litiope, Litiopa, genre nou- veau de Mollusques gasteropodes Annales des Sciences Naturelles. 16(3):303-307. Robertson, R. 1971. Scanning electron microscopy of plank- tonic larval marine gastropod shells. The \'eliger 14(1):1- 12, 9 pis. Sacco, F. 1895. I Molluschi dei terreni Terziarii del Piemonte e della Liguria. Pt. 18 (Melaniidae, Littorinidae, Fossari- dae, Rissoidae, Hydrobiidae, Paludinidae, e \'alvatidae). Turin, 52 p., 1 pi. Smith, E. A. 1875. Remarks on the genus Alaba, with the description of a new species. Proceedings of the Zoological Society of London 1875:537-540. Thiele, J. 1929. Handbuch der Systematischen Weichtier- kunde. Part 1. Jena, 376 p., 470 figs. Tryon, G. W. 1882. Manual of concholog)-, first series, vol. 4:5-276, 58 pis. Philadelphia. Wenz, W. 1938. Gastropoda, 1. In: Schindewolf Handbuch der Palaozoologie 6(1):848 p., 2479 figs. Berlin. THE NAUTILUS 101(1 ):19-24, 1987 Page 19 Seasonal Recruitment of Marine Invertebrates to Hard Substrates on Georges Bank and the Eastern Continental Shelf of the United States Carl J. Berg, Jr. Marine Biological Laboratory Woods Hole, MA 02543, USA Bradford Butman U.S. Geological Survey Woods Hofe. MA 02543, USA Julie A. Early Marine Biological Laborator\ Woods Hole. MA 02543, USA Ruth D. Turner Harvard University Cambridge, MA 02138, USA ABSTRACT Seasonal recruitment of marine invertebrates to hard substrates placed on the U.S. continental shelf from 1978 to 1981 was studied. A large fouling community was present at the bottom of Georges Bank and distinct patterns of settlement were ob- served for wood-boring pholads {Xylophaga). barnacles (Chi- rona hameri). and jingle shells (Anomia squamula)- Seasonal changes in gonadal development of the pholads suggested late summer and late fall spawnings. Examination of wood samples from 85 stations helped to document the bath\ metric and geo- graphic distribution of nine species of pholads and eight species of teredinids on the US continental shelf. Key words: Recruitment; in\ertebrate larvae; hard substrates; wood panels; boring organisms; settlement; continental shelf; Georges Bank. INTRODUCTION This study was designed to examine patterns of seasonal recruitment of marine invertebrates to hard substrates on the continental shelf. It was conducted in conjunction with studies of sediment transport on the eastern United States continental shelf (Butman & Folger, 1979). Wood was chosen as the substrate so that organisms that live both in (wood-boring mollusks) and on hard substrates could be studied. Annual recruitment of animals with planktonic larvae could serve as a natural biological in- dicator of the effects of oil and gas drilling activities on the continental shelf. MATERIALS AND METHODS Settling panels of soft spruce (3.6 x 8.7 x 31.0 cm) were attached with plastic straps to bottom tripod sys- tems designed to measure processes of bottom-sediment movement on the continental shelf (Butman & Folger, 1979). Samples were obtained from a total of 12 stations over a 3-year period (table 1; figures 1, 2). The bottom tripod systems measured water temperature, current, pressure, and light transmission, and photographed the seafloor every few hours (Butman & Folger, 1979). Panels were strapped to the tripods in a horizontal orientation approximately 1 m above the seafloor. Tripods were de- ployed for periods averaging 4 months duration (figure 2).' The entire panels were preserved in approximately 7% formalin seawater soon after the tripods were re- covered. They were later examined under a dissecting microscope to determine species and number of individ- uals present, and to estimate the percent surface covered by each species. The presence of larvae or newly set juveniles was noted. Examples of each species were re- moved and stored in ethanol for identification. Wood borers were dissected from the panels, identified to species, and their shells removed. Tissues were embed- ded in paraffin, sectioned at 7 ^m, stained with hema- toxN'lin and eosin using standard histological procedures, and analyzed for gonadal ripeness. Another set of samples of wood borers was obtained from the L^.S. National Marine Fisheries Service (NMFS), which collected wood in its sampling gear during sur- veys of fisheries stocks on the continental shelf. Over a 5-year period (1976-81) a total of 142 pieces of wood was obtained from 85 stations, ranging from 34°N to 42°N at depths of 18 to 183 m (figure 1). A third set of samples was received from a joint NMFS- USGS submarine cruise at 360 m on the continental slope near 39°03'N, 72°46'W (July, 1978). Wood borers dis- sected from all of these samples were treated identically to those obtained from the tripod panels. Page 20 THE NAUTILUS, Vol. 101, No. 1 ^. Table 1. Depth and location of monitoring stations. ♦i4f 39^ Depth Latitude Longitude Area Station (m) (X) (W) Georges A 85 40°51.2' 67°24.1' Bank K 64 41°02,2' 67°.33.5' (41°) P 71 40°29.0' 70°30,2' Q 67 40°29.9' 70°1.3.0' LCA 100 40°34.2' 67°44.8' Mid-Atlantic B 60 38°43.5' 73°36.5' (39°) D 41 38°58.9' 74°02.9' E 59 39°.57.1' 72°35.6' F 234 .38°31.0' 70°16,9' Soutlicrn A 44 32°33.7' 78°39.5' Atlantic B 47 31°06.8' 80°10.6' (32°) D 86 32°32.5' 78°37.5' s® •/32" ing pholads {Xylophaga atlantica Richards, 1942), but other species occurred as well (table 2). Greatest surface cover, nearly 90% at times, was provided by A. squa- mula, C. hameri, and the suite of hvdroid species (table 2). The timing of larval settlement was determined from the number and size of animals on the panels. The pres- ence of larval forms or newly metamorphosed juveniles indicated that recruitment, but not necessarily spawn- ing, had just occurred. The presence of large animals suggested that recruitment occurred during the early part of panel deployment, but because little is known of growth rates of invertebrates on the continental shelf, exact timing of recruitment could not be determined. Panels that were submerged for short periods (e.g., a panel deployed for 26 days at Station P in October, 1978) provided better resolution of the timing of re- cruitment than panels deployed for the average 4-month Figure 1. Eastern continental shelf of the I'nited States with offshore 200-m contour line. Shading indicates area surveyed by the U.S. National Marine Fisheries Service during this study. Locations of the U.S. Geological Survey long-term monitoring stations are indicated by dots and their appro.ximate latitudes. Exact locations of stations are given in table 1. RESULTS Georges Bank (Five Stations, 64 to 99 m) The number and species of fouling organisms on each panel were dependent on a number of factors including recruitment, competition, predation, and succession. However, obvious patterns in colonization were ob- served over the 3-year (1978-82) sampling period. The most consistently present organisms on the wood panels were jingle shells {Anomia squamula Linne, 1758), bar- nacles (Chirona hameri Ascanius, 1767), and wood-bor- W J S N J W M Figure 2. Sampling periods of U.S. Geological Survey tripods on the continental shelf of the eastern United States. Station locations are listed in table 1 and shown in figure 1. C. J. Berg, Jr. ct al.. 1987 Page 21 Table 2. Fouling organisms present on wood panels from Georges Bank Cnidarians Hsdrozoans Tubularia crocea (L. Agassiz, 1862) Tubularia couthomji L. Agas- siz, 1862 Pennaria tiarella (Avres, 1854) Clijtia edwardsi (Nutting, 1901) Anthozoans Metridium senile (Linne, 1758) Annelids Polychaetes Lepidonotus squamatus (Linne, 1758) Antinoe sarsi (Kinberg, 1855) Arthropods Pvcnogonids Callipallene brevirostris (Johnson, 1837) Cirrepedia Chirona hameri (Ascanius, 1767) Amphipods Gammarus annulatus Smith, 1874 Caprellids Aeginina longicornis (Kroy- er, 1843) Mollusks Eolids Eubranchua pallidus (Alder and Hancock, 1842) Bivalves Anomia squamula Linne, 1758 Xijlophaga atlantica Rich- ards, 1942 X. species 1, 2, 3, 4 (Turner, ms.) Placopecten magellanicus (Gmehn, 1791) Ectoprocts Microporella eiliata (Pallas, 1766) Barentsia laxa Kirkpatrick, 1890 period. Finally, because the timing of deployment var- ied slightly each year, different periods were sampled. Interpretation of the data was difficult, but the repeat- ability of distinct periods of settlement during the 3 years of the study sampled is remarkable (figure 3). Newly set larvae of Anomia squamula occurred on panels recovered in October and March; animals with shells less than 2 mm occurred on panels recovered in April and the beginning of June. Large numbers of an- imals settled on the panels deployed from October to May, with little or no recruitment during the summer months. Chirona hameri cyprid larvae and newly metamor- phosed juveniles were collected in May, June, and Au- gust, suggesting spring and summer recruitment. Panels deployed during fall and winter were notably free of barnacles. Xylophaga atlantica larvae or juveniles less than 1 mm in shell length were collected in October, Decem- ber, early March, and August. Panels deployed in the spring, during periods of coldest bottom-water temper- 40r :0 20 10 mOPHACA ■6 & •ft 1 1 1 r 1 SNJMMJSNJMMJSNJM 600 400 I5°C 10° 5° IMMJ5NJMMJSNJMM ANOMIA ir -h 6 ir !l000 800 600 400 200 Figure 3. Mean seasonal abundance of Anomia squamula, Chirona hameri, and Xylophaga atlantica on fouling panels recovered from the Georges Bank. Stars indicate periods of settlement as determined by the presence of newly settled an- imals on the panels. The mean monthly bottom-water temperatures measured by the tripod systems are shown in the middle graph. Tempera- tures indicated by solid dots (•) are from Station A, circles (O) from Station K, open squares (D) from Station Q, and open triangles (A) from Station LC. For a more detailed description of the seasonal cycle of temperature at Station A on Georges Bank, see Butman and Beardsley (in press). atures on the Georges Bank (figure 3), had the least amount of recruitment. This same pattern was observed for the scallop Placopecten magellanicus Gmelin, 1791, which was collected only from October to mid-March and again from August to January. Mid-Atlantic Region (45 Stations, 41 to 234 m) The single panel submerged at the shallow-water station on the Middle Atlantic Bight (41 m) from October, 1978 to March, 1979 was covered with hydroids and mud tubes. Fifty-nine specimens of Xylopholas altenae Tur- ner, 1972 less than 1.56 mm in shell length and a few large Anomia squamula (8.5 mm) were also removed. At intermediate-depth stations (59 and 66 m), hydroids were present May through December. Based upon the presence of newly set juveniles, it appears that Anomia squamula set only during that period as well. Very small numbers of recently metamorphosed X. atlantica were found throughout the year in every panel, with the ex- ception of a single panel submerged May through Oc- tober, 1978 when water temperatures were at a low of 5 to 9 °C. Panels submerged in subsequent years over- lapped this period and showed settlement. At the deep station (234 m) the only fouling organism was X. atlan- tica. Both large and newly metamorphosed specimens Page 22 THE NAUTILUS, Vol. 101, No. 1 Table 3. Wood-boring mollusks collected during this study along the continental shelf of the eastern I'liited States. Aster- isk (*) indicates range extensions. Pholadidae Xylophaga atlantica Flich- ards. 1942 Jouannetia qtiillingi Tur- ner, 1955* Xylopholas altenae Turner, 1972* Martesia jragilis Wrrill and Bush. 1890 Barnea truncata (Say, 1822) Xylophaga species 1. Tur- ner, nis. Xylophaga species 2. Tur- ner, ms Xylophaga species 3. Tur- ner, ms. Xylophaga species 4. Tur- ner, ms* Teredinidae Teredo navalis Linne, 1758 Bankia gouldi (Bartsch, 1908) Bankia carinata {Gray, 1827) Lyrodus floridanus "(Bartsch, 1908) Nototeredo kiioxi (Bartsch, 1917) Psiloteredo megotara Hanley, 1848 Teredothyra matocotana (Bartsch, 1927) Teredora malleolus (Tur- ton, 1822) were removed from the panel, indicating settlement throughout the period of submergence. Southern Atlantic Region (Three Stations, 44 to 86 m) Tripods were deployed in the South Atlantic Bight over an 11-month period in 1978. Recruitment at mid-shelf depths (44 and 47 m) was distinctly different from re- cruitment at the 86-m station. At the shallow stations the wood borers of Xylophaga (Turner species 4) and Bankia carinata (Gray, 1827) (table 3) bored into the panels from April through mid-July when water tem- peratures were appro.ximately 19 °C. No wood borers appeared from mid-July through November. Barnacles, Balanus amphitrite (Linne, 1767) and B. veniistus (Linne, 1767), and the bivalves Hiatella arctica (Linne, 1767) and Chione cancellata (Linne, 1767) settled dur- ing February to mid-April. From mid-April to July the panel was covered with hydroids and barnacles. These were also present from July to November, with addi- tional settlement of C. cancellata and the serpulid worm Serpula vermicularis (Liiuie, 1767). A panel placed at the deep station near the edge of the shelf (86 m) from July to December had little surface fouling, but was infested with large wood borers {Xylophaga species 4), Teredothyra matacatona (Bartsch, 1927), and Bankia gouldi (Bartsch, 1908) (table 3), Water temperatures 50 40 ID uj 30 CD •=1 10 0 0 15 10 ■)! 20 « 36 0 N D Figure 4. Percent of population of Xylophaga species with gonads in stage 5 ripe condition and mean gonad inde.x for the months the animals were collected. Monthly sample size is given at the top ol the graph. reached mean monthly values of 18.9 °C for July and a high of 24.4 °C for November. Wood-Boring Mollusks From the total collection of wood samples provided by the tripod deployments and by the U.S. National Marine Fisheries Service, nine species of pholads (Pholadidae) and eight species of shipworms (Teredinidae) were iden- tified (table 3). Xylophaga atlantica was found only north of Cape Hatteras and was the most common pholad in northern areas. It was collected at depths of 42 to 234 m, but only settled on panels at stations deeper than 60 m on the Middle Atlantic Bight and on Georges Bank. An undescribed species of Xylophaga (Turner species 4) settled only at the South Atlantic Bight stations. Its dis- tribution overlapped little with X. atlantica. Xylopholas altenae, previously known from a few deep stations off Florida (Turner, 1972a), was collected at both shallow (41 m) and deep (360 m) USGS stations at 39°N, firmly establishing this northern range extension. Only single samples of the other pholads were collected. Histological examination of the gonads of the pholads indicated gonadal ripening during the spring and spawning during summer and late fall (figure 4) when bottom water temperatures exceeded 10 °C on the Georges Bank. With a long planktonic stage predicted (Culliney & Turner, 1976), the larvae would not be ex- pected to settle and metamorphose until the fall and winter. Table 4-. Anomia size analysis from data of Merrill (1962) and Merrill and Kdwards (1976), Buoy Location Dates in field Mean size (mm) of Anomia Nantucket Lightship Buov 40°33'N, 69°28'\V 10/8/57-5/10/58 X = 4,7 4 Davis Shoals #1 Buov 40°57'N, 69°55'W 5/7/57-5/15/58 X = 9, 1 4 Davis Shoals U'2 Buoy 40°57'N, 69°55'W 5/15/58-11/10/58 X = 2.4 C. J. Berg, Jr. ct al., 1987 Page 23 DISCUSSION The observed seasonal settlement of the key species {Anomia squamula, Chirona hameri, and Xylophaga at- lantica) is quite striking. There are only a few studies in the literature that discuss seasonal settlement of these organisms. Seasonality of occurrence of Anomia squamala has been reported. Lebour (1938) found A. squamula larvae common in the plankton throughout the year off Eng- land, but especially in earl> autumn. Jorgensen (1946) stated that A. squamula spawn from July to September off Denmark, but larvae were also noted in November and December. Dons (1936; in Jorgensen, 1946) reports attachment of young to occur only during 3 months in southern Norway, with a peak in either August or Sep- tember. Merrill (1962) and Merrill and Edwards (1976) studied A. squamula settlement on surface buoys just south of Georges Bank and found heavy settlement in the autumn (table 4), as reported in this study. It ap- pears, therefore, that throughout its distribution in northern latitudes, A. squamula has greatest recruitment during autumn and winter. Off New England, settle- ment occurs both at the surface and at the bottom dur- ing this time. Insufficient data are provided in the earlier papers to correlate settlement with environmental fac- tors such as water temperature. We could find no reference to seasonality of spawning and settlement of C. hameri, nor to other species of barnacles on Georges Bank. Based on the data presented here, settlement of C. hameri at the bottom on Georges Bank appears restricted to a short period from late April through Jul\ , Almost nothing is known about the life history and reproductive biology of species of Xylophaga. Short-term placement of panels has shown that settlement of X. dorsalis occurs between December and April off Mill- port, Scotland (Turner & Johnson, 1971), and that set- tlement of A', washingtona occurs between November and January off Oregon (Turner and Johnson, 1971) and year-round in California (Haderlie, 1983). Although X. atlantica has been reared to metamorphosis (Culliney & Turner, 1976) little else is known concerning its repro- ductive or general biology. Our work suggests spawning occurs in summer and again in late fall for these pholads. On Georges Bank, X. atlantica metamorphoses and bores into wood primarily between September and February. At the Mid-Atlantic site this occurs 2 months later (No- vember through April) and again later at the Southern Atlantic site (December through June). This reflects dif- ferences in periods of peak water temperatures at these three areas. Turner (1955) reviewed the available information on pholads and emphasized how little was known. Purchon (1941) discussed the biology of X. dorsalis, including descriptions of general anatomy and feeding. Tipper (1968) was the first to study the ecology of deep-sea wood borers. He found X. washingtona in panels set at depths of 200, 500, and 1,000 m on the continental ter- race off Oregon. In general, the number of X. washing- tona per square centimeter decreased with increasing depth, and increased over time. The teredinid Bankia setacea was also present in his collecting panels set at 200 m, but he did not recover them from shallower depths, and attributed this to seasonal patterns of repro- duction and coastal upwelling. Haderlie (1983) found the overlap in B. setacea and X. washingtona to occur only between 35 and 70 m in Monterey Bay, California. Below that, X. washingtona was the only wood borer present and settled during all months of the year. Water temperatures at 70 m averaged 10 °C and were only slightly colder at deeper sites. DePalma (1963), in a series of tests conducted off Florida, also documented an overlap in bathymetric ranges of teredinids [Bankia carinata) and pholads (Xy- lophaga sp.) Bankia carinata was found in test panels set as deep as 165 m, but only in low numbers. Pholads were common in panels set at 90 m, but none were found at depths less than 30 m (Turner, 1966). In recent tests, DePalma obtained Teredothyra matacotana in wood set at 200 m, making this the deepest record for teredinids invading new wood (Turner, personal obser- vation). However, pholads invade the depths of the oceans (Turner, 1972a,b, 1973a,b, 1981). In the northwestern Atlantic, Teredo navalis and Xy- lophaga atlantica exhibit overlapping bathymetric ranges, with T. navalis extending from intertidal down to 66 m and X. atlantica from 18 m (Turner & Johnson, 1971) to 234 m. In our study two minute teredinids were collected with X. atlantica in a panel at 67 m on Georges Bank and one T. navalis was collected among the X. at- lantica at 60 m on Mid-Atlantic Station B. In the South Atlantic Bight Xylophaga (Turner species 4) occurred with Bankia carinata at 44 m and with Teredothyra matacotana and Bankia gouldi at 86 m. These panels were carried quickly to the bottom, and so could not have become infested on the way down. Consequently, the reported occurrence of these borers indicates their true bathymetric range. Wood collected from the bot- tom by the National Marine Fisheries Service was prob- ably infested with teredinids at the surface or while slowly sinking from the surface, and cannot be used to describe bathymetric distributions. Some planktonic larvae of marine invertebrates live in the water column for extended periods of time before they settle to the bottom and metamorphose into juve- nile benthic forms. During their planktonic stage they serve as food for other pelagic organisms, especially fish. Alteration of the marine environment by outer conti- nental shelf exploratory drilling and production might have long-term effects upon phytoplankton production, zooplankton production (including larvae), and fish pro- duction. The use of wood panels to measure recruitment might be used to measure some of these perturbations, although the variability observed in this study and the difficulty in separating larval availabilit) and observed recruitment suggests that interpretation of such simple monitoring studies would be difficult. Seasonal patterns Page 24 THE NALTILL'S, Vol. 101, No. 1 of larval recruitment might be better defined and cor- related to physical parameters (water temperature, cur- rents, etc. ) if panels were deployed for short periods in overlapping succession. ACKNOWLEDGEMENTS We thank Nancy Adams, Donald Flescher, and the staffs of the Woods Hole branches of the U.S. Geological Sur- vey and the National Marine Fisheries Service for help in collecting and processing samples. The biological pro- gram was supported b\' new initiative funds from the Woods Hole Oceanographic Institution Sea Grant Pro- gram (04-8-M01-149), and ONR contract NOOO 14-76- C-0281, NR 104-687 with Harvard University. The bottom tripod observations were supported by the U.S. Geological Survey and the U.S. Bureau of Land Man- agement through Memoranda of Understanding AA551- MU8-24, AA551-MU9-4, AA551-MU0-18, AA551-MU8- 21, AA551-MU8-13, AA551-MU9-8, and Interagency Agreement AA851-IA1-17. LITERATURE CITED Butman, B. and R. C. Beardsley. In press. Long-term obser- vations on the southern flank of Georges Bank; Part I. Seasonal cycle of current, temperature, stratification and wind stress. Journal of Physical Oceanography. Butman, B. and D. W. Folger. 1979. An instrument system for long-term sediment transport studies on the continen- tal shelf. Journal of Geophysical Research 84:1215-1220. Culliney, J. L. and R. D. Turner. 1976. Larval development of the deep-water wood boring bivalve, Xylophaga atlan- tica Richards (Mollusca, Bivalvia, Pholadidae) Ophelia 15: 149-161. DePalma, J. R. 1963. Marine boring and fouling organisms off Fort Lauderdale, Florida. U.S. Naval Oceanographic Office. Marine Sciences Department, hiformal Manu- script No. 0-70-62a, 27 p. Haderlie, E. C. 1983, Depth distribution and settlement times of the molluscan wood borers Bankia setacea (Tryon, 1863) and Xylophaga washingtona Bartscli, 1921, in Monterey Bay. The VeUger 25:339-342, 2 pis. Jergensen, C B. 1946. Lamellibranchia. Meddelelser Kom- missionen Danmarks Fiskeri- og Havunders0gelser, Serie Plankton 4:277-311. Lebour, M. V. 1938. Notes on the breeding of some laniel- libranchs from Plymouth and their larvae. Journal of the Marine Biological Association of the L'nited Kingdom 23: 119-144. Merrill, A. S. 1962. Variation and change in surface sculpture in Anomia acoleata. The Nautilus 75:131-138 Merrill, A S. and R L. Edwards. 1976. Observations on mollusks from a navigation buoy with special emphasis on the sea scallop Placopecten magellanicus. The Nauti- lus 90:54-61. 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: 1-39. Tipper, R. C. 1968. Ecological aspects of two wood-boring molluscs from the continental terrace off Oregon. Doc- toral dissertation, Oregon State Universit) , Corvallis, OR, 137 p. Turner, R. D. 1955, The family Pholadidae in the western Atlantic and the eastern Pacific. Part II — Martesiinae, Jouannetiinae, and Xvlophaginae. Johnsonia 3:65-160, pis. 35-93. Turner, R. D. 1966. Implications of recent research in the Teredinidae. Beihefte zu Material und Organismen, Ber- lin, Heft 1:437-446. Turner, R. D. 1972a, A new genus and species of deep-water wood-boring bivalves (Mollusca, Pholadidae, Xylophag- ainae). Basteria 36:97-104. Turner, R. D. 1972b. Xyloredo, a new teredinid-like abyssal wood-borer (Mollusca, Pholadidae, Xylophagainae). Bre- viora 397:1-19, pis. 1-6. Turner, R, D, 1973a, Deep water wood-boring mollusks. Pro- ceedings of the Third International Congress on Marine Corrosion and Fouling, National Bureau of Standards, Gaithersburg. Mar\land, p. 836-841. Turner, R. D 1973b. Wood-boring bivalves, opportunistic species in the deep sea. Science 180:1377-1379. Turner, R. D. 1981. "Wood islands" and "thermal vents" as centers of diverse communities in the deep sea Biolo- giya Morya 1:3-10. Turner, R. D. and A. C. Johnson. 1971. Biology of wood- boring molluscs. In: Jones, E. B. G, and S. K. Eltringham (eds.). Marine borers, fungi and fouling organisms of wood. Organisation for Economic Co-operation and Develop- ment, Paris, p. 259-301. THE NAUTILUS 101(l);25-32, 1987 Page 25 North American Hydrobiidae (Gastropoda: Rissoacea): Redescription and Systematic Relationships of Tryonia Stimpson, 1865 and Pyrgtdopsis Call and Pilsbry, 1886 Robert Hershler Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC: 20560, USA Fred C. Thompson Florida State Museum University of Florida Gainesvilie, FL 32611, USA ABSTRACT Anatomical details are provided for the type species of Tryonia Stimpson, 1865, Ptjrgulopsis Call and Pilsbry, 1886, Fonteli- cella Gregg and Taylor, 1965, and Microamnicola Gregg and Ta\ lor, 1965, in an effort to resolve the systematic relationships of these taxa, which represent most of the generic-level groups of Hydrobiidae in southwestern North America. Based on these and other data presented either herein or in the literature, Hyalopyrgus Thompson, 1968 is assigned to Tryonia, and Fontelicella. Microamnicola, Natricola Gregg and Taylor, 1965, Marstonia F. C, Baker, 1926, and Mexistiobia Hershler, 1985 are allocated to Pyrgulopsis. The ranges of both Tryonia and Pyrgulopsis include parts of eastern and western America and northern Mexico. Tryonia is closely related to a group of North and Central American littoridinine genera having an elongate-conic shell and (mam- miform) glandular penial lobes, and Pyrgulopsis (Nympho- philinae) is closely allied to Cincinnatia Pilsbry, 1891 from eastern North America. INTRODUCTION Prosobranch snails of the family Hydrobiidae comprise a major faunal element of North American freshwaters, numbering some 28 genera and 148 species (Burch, 1982). Despite their diversity and ubiquity. North American Hydrobiidae are poorly understood in terms of systematics, as the anatomy of few species is known. While recent advances have been made in the system- atic study of southeastern Hydrobiidae (Thompson, 1968, 1969, 1977, 1984; Thompson & McCaleb, 1978), the fau- na of other large expanses of territory is virtually un- studied. One such fauna is that of the arid Southwest. Of the generic-group taxa found in this region, onK Flurijini- cola Stimpson, 1865 has received sufficient morpholog- ical study to allow clarification of its relationships (Thompson, 1984). Relatively little is known of Pyrgu- lopsis Call and Pilsbry, 1886, Tryonia Stimpson, 1865, and Fontelicella Gregg and Taylor, 1965, the latter two of which comprise more than 30 species (mostK unde- scribed) in the Southwest. Taylor (1966) placed Tryonia in the Littoridininae Taylor, 1966 on the basis of its turreted shell and glandular penial lobes. It is clear from the initial descriptions and subsequent studies illustrat- ing the penis (Russell, 1971: fig. 4; Taylor, 1983:16-25) that Fontelicella and its subgenera, Natricola Gregg and Taylor, 1965 and Microamnicola Gregg and Taylor, 1965 belong to the Nymphophilinae Taylor, 1966 (see Thompson, 1979). While the type species of Pyrgulop- sis, P. nevadensis (Stearns, 1883), has not received an- atomical study, the penes of several eastern species have been examined b\' Thompson (1977), who suggested that the genus may be a nymphophiline. The scant published morphological data do not, however, allow meaningful comparisons of the above with other Hydrobiidae. Our anatomical study of the type species of Tryonia and Hyalopyrgus Thompson, 1968 showed that Hyalo- pyrgus, endemic to Florida (and placed in the Littori- dininae by Davis et al., 1982), should be allocated to Tryonia. Similarly, study of type species and published accounts indicated that Fontelicella, Natricola, Mi- croamnicola, as well as Mexistiobia Hershler, 1985 (from northern Mexico) and Marstonia F. C. Baker, 1926 (widespread in eastern North America) should be allo- cated to Pyrgulopsis. In this paper we redescribe Tryon- ia and Pyrgulopsis and briefly discuss their affinities. MATERIALS AND METHODS Anatomical illustrations given in this paper are based on study of the following lots (representing fully relaxed alcohol material unless otherwise indicated): Tryonia clathrata Stimpson, 1865, Moapa Springs, Clark County, NV, USA, USNM 850291; Hyalopyrgus aequicostatus (Pilsbry, 1889), Lake Dora, Lake County, FL, USA, USNM 847212; Alexander Springs, Lake County, FL, USA, UF uncatalogued lot; Pyrgulopsis nevadensis, re- hydrated (in Bouin's solution) bodies, south end of Pyr- amid Lake, Washoe County, NV, LISA, UF uncata- logued lot; Pijrgulopsis archimedis S. S. Berry, 1947, unrela.xed. Upper Klamath Lake, Klamath County, OR, Page 26 THE NAUTILUS, Vol. 101, No. 1 Figure 1. Photograph (SEM) of holotype of Tryonia claihrata Stimpson, Colorado Desert, CA, USA (but see Taylor, 1966: 197), ANSP 27969. Shell height is 4.36 mm. Figure 2. Close- up photograph of shell of Tryonia dathrata Stimpson, Moapa Springs, Clark County, NV, USA, USNM 850291, showing sculptural pattern. The height of the portion of shell photo- graphed is 2.36 mm. Figure 3. Photograph of shell of Tryon- ia aequicostata (Pilsbry), Lake Dora, Lake County, FL, USA, USNM 847212, printed to same enlargement as figure 1. Fig- ure 4. Photograph of paratype of Pyrgulopsis nevadensis, south end of Pyramid Lake, Washoe County, NV, USA, USNM 75450, printed to same enlargement as figure 1 Figure 5. Photograph of shell of Pyrgulopsis lustrica (Pilsbrv), Little Lakes. Herkimer County, NY, USA, USNM 28085, printed to same enlargement as figure 1. Figure 6. Photograph of para- type of Pyrgulopsis californiensis (Gregg and Taylor), Campo Creek, San Diego County, CA, USA, USNM 850292, printed to same enlargement as figure 1. Figure 7. Photograph of shell of Pyrgulopsis micrococcus (Pilsbry), Springdale Springs, Nye County, NV, USA, USNM 850297, printed to same en- largement as figure 1. Figure 8. Photograph of shell of Pyr- gulopsis manantiali (Hershler), spring at Tierra Blanca, SW of Cuatro Cienegas, Coahuila, MEX, ANSP A9888L, printed to same enlargement as figure 1. Figure 9. Photograph (SEM) of central radular teeth of Tryonia aequicostata (Pilsbry), Lake Dora, Lake County, FL, USA, USNM 847212. Scale bar equals 10 ^m. Figure 10. Photograph of protoconch of Tryonia aequicostata (Pilsbrv) (from same lot as above). Scale bar equals 150 nm. Figure 11. Photograph of central radular teeth of Tryonia dathrata Stimpson, Moapa Springs, Clark County, NV, USA, USNM 850291. Scale bar equals 10 fim. Figure 12. Photograph of protoconch of Tryonia dathrata Stimpson (from same lot as above). Scale bar equals 150 nm. 1985, small spring at Tierra Blanca, SW of Cuatro Cie- negas, Coahuila, ME.X, ANSP A98881. Snails were dissected in dilute Bouin's solution at 50 x using a Wild M-8 dissecting microscope. Ciliation pat- terns on the cephalic tentacles and penis were examined using a Hitachi S-570 scanning electron microscope, with the animals having first been graded into 100% ETOH and dried using a Denton DCP-1 Critical Point Drier. Shells and radulae were cleaned with Clorox and then photographed using the scanning electron microscope. USA, ANSP A602b; Pyrgulopsis letsoni (Walker, 1901), creek W of Crenshaw Lake, Oakland County, MI, USA, UF 91726; Pyrgulopsis scalariformis (Wolf, 1869), Mer- amec River, 12.0 km SE of Leesburg, Crawford County, MO, USA, UF 91727. Fontelicella (sensu stricto) cali- forniensis Gregg and Taylor, 1965, Campo Creek, San Diego County, CA, USA, USNM 850292 (paratypes); Fontelicella (Microamnicola) micrococcus (Pilsbry in Stearns, 1893), Springdale Springs, Nye County, NV, USA, USNM 850297; Mexistiohia manantiali Hershler, SYSTEMATICS Genus Tryonia Stimpson, 1865 Tryonia Stimpson, 1865:54. Type species: Tryonia dathrata Stimpson, 1865:54, by original designation; 1865:54. Hyalopyrgus Thompson, 1968:43. Type species: Bythinella aequicostata Pilsbr\, 1889:86, by original designation; Thompson, 1968:45. Diagnosis: Shell (figures 1-3) colorless, transparent, elongate-conic to turreted, 1.7-7.0 mm tall with 4.0-8.0 R. Hershler and F. G. Thompson, 1987 Page 27 Figure 13. Photograph (SEM) of left tentacle of Tryonia clathrata Stimpson, Moapa Springs, Clark County, NV, USA, USNM 850291, showing ciliary tracts. Scale bar equals 176 ^ni. Figure 14. Photograph of right tentacle of Tryonia clathrata Stimpson (from same lot as above). Scale bar equals 170 /um. Figure 15. Close-up photograph of ciliary tracts on right tentacle of Tryonia clathrata Stimpson (same specimen as above). Scale bar equals 30 ^m. Figure 16. Photograph of left tentacle of Tryonia aequicostata (Pilsbry), Alexander Springs, Lake County, FL, USA, UF uncatalogued lot. Scale bar equals 176 ixm. Figure 17. Photograph of right tentacle of Tryonia aequicostata (Pilsbry) (from same lot as above). Scale bar equals 200 nm. Figure 18. Photograph of penial tip of Tryonia clathrata. Moapa Springs, Clark County, NEV, USA, USNM 850291, showing sparse ciliation, terminal papilla, and blunt swelling on inner (left) side. Scale bar equals 50 ^ni. whorls; typically high-spired with rounded whorls and indented sutures. Aperture simple, unthickened, and complete. Umbilicus narrow or absent. Sexual dimor- phism pronounced, with males often half of female shell height. Protoconch (figures 10, 12) flat or slightlv pro- truding, smooth or slightly wrinkled. Teleoconch sculp- ture consisting of fine growth lines, sometimes coupled with weak spiral lines or collabral striations or varices. Central tooth of radula (figures 9, 11) broader than tall, with 1-3 pairs of basal cusps. Digestive gland without anterior lobe. Cephalic tentacles with several elongate ciliary tracts (figures 13-17). Flattened penis (figures 19, 20) elongate and slender, with a single, enlarged glan- dular (mammiform) lobe at its base and 1-4 smaller glandular lobes on the inner curvature. Distal portion of penis ciliated (figure 18) to varying degrees, base some- times also ciliated. Tip of penis with blunt swelling on inner curvature. Females ovoviviparous, with 3-15 em- bryos brooded in enlarged capsule gland (figure 21). Capsule gland with muscular sphincter at anterior end. Pallial oviduct reflected posteriorly, albumen gland re- duced in size (figure 22, Ag). Small-sized bursa copula- trix and seminal receptacle ventral to albumen gland; coiled seminal receptacle duct opens into short sper- mathecal duct (figures 23, 24, Osr). Species included: Bijthinella aequicostata; Bythinella brevissima Pilsbry, 1890:64; Potamopyrgus cheatumi Page 28 THE NAUTILUS, Vol. 101, No. 1 0.75 mm Figure 19. Penis of Tnjonia clathrala Stimpson, Moapa Springs, Clark County, NV, USA, USNM 850291- Figure 20. Penis of Tnjonia aequicostata (Pilsbry), Alexander Springs, Lake County, PL, USA, UF uncatalogued lot. Patterns of ciliation are not shown. Flo = penial lobe. Pilsbry, 1935:91; Calipyrgula circumstriata Leonard and Ho, 1960a:125; Tnjonia clathrata; Paludestrina diaboli Pilsbry and Ferriss, 1906:125; Paludestrina imitator Pilsbry, 1899:121; Calipyrgula pecosensis Leonard and Ho, 1960b:110; Amnicola protea Gould, 1855:129; Pa- ludestrina stokesi Arnold, 1903:22. The identity of the Central and South American taxa assigned to Tryonia by Taylor (1966) is uncertain due to lack of anatomical study. Distribution: Tryonia occurs in much of Florida as well as in the arid Southwest, including parts of California, Figure 2L Tryonia clathrala Stimpson (without shell), Moa- pa Springs, Clark C:ounty, NV, USA, I'SNM S.50291. viewed from the right side. Note the enlarged capsule gland (C^g) with embryos (dotted circles). The thickened dots on the digestive gland (Dg) are pigment granules. C;g = capsule gland, Ct = ctenidium, Dg = digestive gland, Edg = posterior end of diges- tive gland. In = intestine, Ki = kidney. Op = operculum, Pc = pericardium, St = stomach. Nevada, Arizona, New Mexico, and Texas, and northern Mexico. Remarks: Given the overall similarity between the Flo- ridian and southwestern species, even extending to de- tails of the bursa copulatrix complex (figures 23, 24), there can be no doubt that these species belong to a single genus. Tryonia belongs to a group of littoridinines having an elongate-conic shell and mammiform glan- dular lobes on the penis that includes Aphaostracan Thompson, 1968, Littoridinops Pilsbry, 1952, Mexipyr- gus Taylor, 1966, and Pyrgophorus Ancey, 1888 (but not Durangonella Morrison, 1945; contrar\- to Hershler, 1985). Tryonia is distinguished from the above by its turreted shell and unique position of its penial lobes. Genus Pyrgulopsis Call and Pilsbry, 1886 Pyrgiilopsis Call and Pilsbry, 1886:9. Type species: Ptjrgiila i\evadetisis Stearns, 1883:173, bv original designation; Call and Pilsbry, 1886:9. Marstonia F. C. Baker, 1926:195. Type species: Amnicola lus- trica Pilsbry, 189053, bv original designation; F. C. Ba- ker, 1926:195. Fontelicella Gregg and Taylor, 1965:103. Type species: Fon- telicrlla californiensis Gregg and Ta\lor, 1965:109, by original designation; Gregg and Ta\lor, 1965:104. Natricola C-regg and Taylor, 1965:108. T>pe species: Pomal- iopsis rohusta Walker, 1908:97, b\ original designation; Gregg and Taylor, 1965:109 Microamnicola Gregg and Taylor, 1965:109. Type species: Amnicola micrococcus Pilsbry in Stearns, 1893:277, by original designation; Gregg and Taylor, 1965:109. R. Hershler and F. G. Thompson, 1987 Page 29 Sts Osd 0.5 mm Figure 22. Posterior portion of pallial oviduct and associated organs and structures of T. clathrata Stimpson, Moapa Springs, Clark County, NV, USA, USNM 850291, viewed from the right. Note the posterior reflection of the palhal oviduct and small albumen gland (Ag). The thickened curving Hne indicates the posterior end of the pallial cavity \g = albumen gland, Bu = bursa copulalri.x, Cg = capsule gland. In = intestine, Oes = oesophagus, Osd = opening of the spermathecal duct, Ov = oviduct, Pc = pericardium, Sd = spermathecal duct, Sts = style sac. Figure 23. Bursa copulatrix complex of Tnjonia clathrata (from same lot as above), with the bursa removed (position indicated by dashed lines) in order to reveal the underlying structures. The visceral ganglion connective (Cvg) is tightly pressed against the oviduct. Bu = bursa copulatrix, Cvg = visceral ganglion connective, Oov = opening of oviduct into albumen gland, Ov = oviduct, Osr = opening of seminal receptacle into spermathecal duct, Sd = spermathecal duct, Sr = seminal receptacle. Figure 24. Bursa copulatrix complex of Tnjonia aequicostata (Pilsbry), Alexander Springs, Lake County, FL, USA, UF uncatalogued lot. The thickened curving line indicates the posterior end of the pallial cavity. Bu = bursa copulatrix, Cvg = visceral ganglion connective, Oov = opening of oviduct into albumen gland, Osr = opening of seminal receptacle into spermathecal duct, Sd = spermathecal duct, Sr = seminal receptacle. Mexistiobia Hershler, 1985:46. Type species; Mexistiobia manantiali Hershler, 1985:47, by original designation; Hershler, 1985:46, Diagnosis: Shell (figures 4-8) globose to elongate-conic, 1.2-8.0 mm in height, with 3.0-6.0 whorls. Aperture simple, sometimes loosened from body whorl. Umbilicus absent to open. Protoconch partly or totally covered with wrinkled pits (Thompson, 1977: fig. 4; Hershler, 1985: fig. 11). Teleoconch smooth or unicarinate on periphery (figure 3), usually with fine growth lines. Radula (figures 25-28) typically taenioglossate, with basal cusps on the central teeth. Mantle and/or penial filament (figures 29, 30, 32, 33) often with distinctive pigment markings. Pe- nis (figures 29-33) with small, distal lobe and narrow, elongate filament. Penial surface with one to fifteen glandular ridges, sometimes on stalked crests. Females oviparous; capsule gland with two tissue sections and a near-terminal opening (figures 34, 35; Thompson, 1977: figs. 5, 7, 10, 11, 18; Hershler, 1985: fig. 14). Oviduct with a single anterior coil on the left side of the albumen gland into which opens the seminal receptacle. Bursa copulatrix typically enlarged and partly posterior to al- bumen gland; bursa duct and oviduct jointly open into anterior portion of albumen gland. Species included: Marstonia agarhecta Thompson, 1969:243; Pyrgulopsis archimedis S. S. Berry, 1947:76; Fontelicella californiensis; Marstonia castor Thomp- son, 1977:130; Amnicola deserta Pilsbry, 1916:111; Marstonia halcyon Thompson, 1977:128; Amnicola hendersoni Pilsbry, 1933:10; Amnicola idahoensis Pils- bry, 1933:11; Pomatiopsis intermedia Tryon, 1865:220; Amnicola letsoni Walker, 1901:113; Amnicola longin- qua Gould, 1855:130; Amnicola lustrica; Mexistiobia manantiali; Amnicola micrococcus; Amnicola neomex- Page 30 THE NAUTILUS, Vol. 101, No. 1 Figure 25. Photograph (SE\4) of central radular teeth of Pyr- gulopsis nevadensis (Stearns), Pyramid Lake. Washoe County, NV, USA, UF uncatalogued lot. Scale bar equals 12.0 ftm. Figure 26. Photograph of lateral teeth of Pyrgttlopsis neva- densis (Stearns). Scale bar equals 12.0 fim. Figure 27. Pho- tograph of inner marginal tooth of Pyrgulopsis nevadensis (Stearns). Scale bar equals 8.6 ^ni. Figure 28. Photograph of outer marginal tooth of Pyrgulopsis nevadensis (Stearns). Scale bar equals 7.5 nm. icana Pilsbry, 1916:111; Marstonia ogmorphaphe Thompson, 1977:120; Amnicola olivacea Pilsbry, 1895: 115; Pyrgulopsis ozarhensis Hinkley, 1915:588; Mar- stonia pachyta Thompson, 1977:121; Amnicola pilsbfiji Baily and Bally, 1952:50; Pomatiopsis rohusta Walker, 1908:97; Ptjrgula scalariformis Wolf, 1869:198; Palii- destrina stearnsiana Pilsbry, 1899:124; Pyrgulopsis wa- bashensis Hinkley, 1908:117. Fossil species assigned to Marstonia and Fontelicella by Taylor (1960) and Gregg and Taylor (1965) are not included. Distribution: Pyrgulopsis occurs in much of eastern North America as well as throughout western North America and parts of northern Mexico. Remarks: Only a limited anatomical study could be made of Ptjrgulopsis nevadensis, the type species of Pyrgulopsis, as only dried bodies were available. We were able to describe its radula (figures 25-28) and penis (figure 29). The species has long been considered en- dangered (Taylor, 1970) and may now be e.xtinct in the sole locality from which living material was ever found. Pyramid Lake. A recent limnological survey of this lo- Figure 29. Penis of Pyrgulopsis nevadensis (Stearns), south end of Pyramid Lake, Washoe County, NV, USA, UF uncat- alogued lot. The dorsal aspect is shown to the left and ventral aspect is on the right. The screened areas indicate glandular ridges whereas the darkened areas are pigmented. Figure 30. Penis of Pyrgulopsis letsoni (Walker), creek W of Crenshaw Lake, Oakland County, MI, USA, UF 91726. Figure 31. Pe- nis of Pyrgulopsis scalariformis (Wolf), Meramec River, 12,0 km SE of Leesburg, Crawford County, MO, USA, UF 91727. Figure 32. Penis of Pyrgulopsis californiensis (Gregg and Taylor), Campo Creek, San Diego County, CA, USA, USNM 850292, Plo = penial lobe, Vd = vas deferens. Figure 33. Penis of Pijrgulopsis micrococcus (Pilsbrv), Springdale Springs, Nye County, NV, USA, USNM 850297.' cality yielded no live individuals (Galat ct al.. 1981) of this species, nor were they found during a recent trip to the lake by one of us (F.G.T.). It is clear from our study that the sole character dis- tinguishing species assigned to Pyrgulopsis and other taxa that we consider congeneric is the presence of a peripheral carina on the shell. Pyrgulopsis is noteworthy tor its diversity in shell and penial morphology. Even within small regions in the .Southwest, groups of species show gradations from globose to elongate-conic shells, or gradations from a simple penis with few ridges to a more complex penis with accessory crests and numerous ridges. The eastern species previously assigned to Mar- stonia and Pyrgulopsis. united by possession of a penis having few glandular ridges and a broad penial lobe (Berry, 1943: fig. 6; Thompson, 1977: figs. 5, 7, 11, 13, 19, 22, 24), clearly intergrade with western species as- signed to Pyrgulopsis, Fontelicella sensu stricto and Mi- croamnicola. We have no doubt that Pomatiopsis ro- Imsta, the type species of Natricola, is also a Pyrgulopsis, based on anatomical data given by Gregg and Taylor R. Hershler and F. G. Thompson, 1987 Page 31 Dbu Figure 34. Left lateral aspect of the paUial oviduct and bursa copulatrix complex of Pyrgiilopsis californiensis (Gregg and Taylor), Campo Creek, San Diego County, CA, USA, USNM 850292. The two tissue sections of the capsule gland (Cg) are indicated by the stippled areas. The thickened curving line indicates the posterior end of the pallial cavity. Ag = albumen gland, Bu = bursa copulatrix, Cg = capsule gland, Cga = capsule gland opening, Dbu = duct of the bursa copulatrix, Sr = seminal receptacle. Figure 35. Left aspect of the pallial oviduct and bursa copulatrix complex of Pyrgiilopsis archi- medis S. S. Berry, L'pper Klamath Lake, Klamath County, OR, USA, ANSP A662B. (1965:108). The unique, stunted appearance of the bursa copulatrix complex of P. manantiali (Hershler, 1985: fig. 14) is probably a result of the extremely minute size of the snail. In other features such as shell form and penial morphology the species clearly conforms to the Pyrgulopsis groundplan. Among nymphophilines that have received anatomi- cal study, Pyrgulopsis is most similar to Cincinnatia Pilsbry, 1891, which has a somewhat larger and broader shell as well as a more complex penis having a very small filament, a large number of glandular ridges, and nu- merous accessory crests (Thompson, 1968: figs. 43-47; Davis & Mazurkiewicz, 1985: figs. 11-15). ACKNOWLEDGEMENTS Drs. G. M. Davis (ANSP), A. Bogan (ANSP), and W, L. Pratt (Museum of Natural History, University of Nevada at Las Vegas), as well as J. J. Landye (Arizona Game and Fish) and K. Auffenberg (Florida State Museum, University of Florida) loaned material necessary for the completion of this report. Mrs. M. Ryan assisted with the preparation of the illustrations. We thank two anon- ymous reviewers for their useful criticisms. LITERATURE CITED Ancey, C, F. 1888. Etude monographique sur le genre Pyr- gulopsis. Bulletins de la Societe Malacologique de France 5:185-202. Arnold, R. 1903. The paleontology and stratigraphy of the marine Pliocene and Pleistocene of San Pedro, California. Memoirs of the California Academy of Sciences 31-420 Baily, J. L. and R. I. Baily. 1951-52. Further observations on the Mollusca of the relict lakes in the Great Basin. The Nautilus 65:46-53, 85-93. Baker, F. C. 1926. Nomenclatural notes on .American fresh water mollusks. Transactions of the Wisconsin Academy of Science, Arts, and Letters 22: 193-205. Berry, E. G. 1943. The .\mnicolidae of Michigan: distribution, ecology, and taxonomy. Miscellaneous Publications of the Museum of Zoology, University of Michigan 57:1-68. Berry, S. S. 1947. A new Pyrgulopsis from Oregon. The Nau- tilus 60:76-78. Burch, J. B. 1982. Freshwater snails (Mollusca: Gastropoda) of North .f^merica. U.S. Environmental Protection .Agen- cy, Contract No. 68-03-1280, EPA-600/3-82-026, 294 p. Call, R. E. and H. A Pilsbry 1886. On Pyrgulopsis. a new- genus of rissoid mollusk, with descriptions of two new forms. Proceedings of the Davenport Academy of Natural Sciences 5:9-14. Davis, G. M. and M, Mazurkiewicz. 1985. Systematics of Cincinnatia winkleyi (Gastropoda: Hydrobiidae). Pro- ceedings of the Academv of Natural Sciences of Phila- delphia 137:28-47. Davis, G. M., M. Mazurkiewicz, and M. Mandracchia. 1982. Spurwinkia: morphology, ssstematics, and ecology of a new genus of North American marshland H\drobiidae (Mollusca: Gastropoda). Proceedings of the Academy of Natural Sciences of Philadelphia 134:14.3-177. Galat, D. L., E. L. Lider, S. Vigg, and S. R Robertson. 1981. Limnology of a large, deep North American terminal lake. Pyramid Lake, Nevada, U.S. Hydrobiologia 82:281-317. Gould, A. A. 1855. New species of land and freshwater shells from western (N.) America, Proceedings of the Boston Society of Natural History 5:127-130. Gregg, VV.'\'. and D. W. Taylor. 1965. Fontelicella (Proso- branchia: Hydrobiidae), a new genus of West American freshwater snails. Malacologia 3:103-110. Hershler, R. 1985. Systematic revision of the Hydrobiidae (Gastropoda: Rissoacea) of the Cuatro Cienegas Basin, Coahuila, Mexico. Malacologia 26:31-123. Hinklev, A. A. 1908. A new species of Pyrgulopsis. The Nau- tilus 21:117-118. Hinklev, .A. ■\. 1915. New fresh-water shells from the Ozark Mountains. Proceedings of the United States National Mu- seum 49:587-589. Leonard, A. B. and T.-Y. Ho. 1960a, New Calipyrgula from Page 32 THE NAUTILUS, Vol. 101, No. 1 Pleistocene of Texas and notes on Cochhopa riogranden- sis. The Nautilus 73:125-129. Leonard, A. B. and T.-Y. Ho. 1960b. A new species of Cal- ipyrgula (H\drobiidae) from the Pleistocene of Texas. The Nautilus 73!ll0-113. Morrison, J. P. E. 1945. Durangonella, a new hydrobiine genus from Mexico, with three new species. The Nautilus 59:18-23. Pilsbry, H. A. 1889. New and little known American mol- lusks. No 1. Proceedings of the Academy of Natural Sci- ences of Philadelphia 41:81-89. Pilsbry, H. A. 1890. Notices of new Amnicolidae The Nau- tilus 4:63-64. Pilsbry, H. A. 1895. New American freshwater mollusks. The Nautilus 8:114-116. Pilsbry, H. A. 1899. Catalogue of the Amnicolidae of the western United States. The Nautilus 12:121-127. Pilsbry, H. A. 1916. New species of Amnicola from New Mexico and Utah. The Nautilus 29:111-112. Pilsbry, H. A. 1933. .*\mnicolidae from Wyoming and Ore- gon. The Nautilus 47:9-12, Pilsbry, H. A. 1935. Western and southwestern Amnicolidae and a new Huniboldtiana. The Nautilus 48:91-94. Pilsbry, H. A. 1952. Littoridina leniiipes (Couper). The Nau- tilus 66:50-54, Pilsbry, H. A. and J. H. Ferriss. 1906. Mollusca of the south- western states. II. Proceedings of the Academy of Natural Sciences of Philadelphia 58:123-175. Russell, R. H. 1971. Mollusca of Fish Springs, Juab County, Utah: rediscovery of Stagnicola pilshryi (Hemphill, 1890). Great Basin Naturalist 31:223-236, Stearns, R, E, C, 1883, Description of a new hydrobiinoid gasteropod from the mountain lakes of the Sierra Nevada, with remarks on allied species and the physiographic fea- tures of said region. Proceedings of the Academv of Nat- ural Sciences of Philadelphia 35:171-176, Stearns, R, E. C, 1893, Report on the land and fresh-water shells collected in California and Nevada by the Death Valley Expedition, including a few additional species ob- tained by Dr C, Hart Merriam and assistants in parts of the southwestern United States, North .American Fauna 7:269-283. Stimpson, W. 1865. Researches upon the Hydrobiinae and allied forms. Smithsonian Miscellaneous Collections 201: 1-59. Taylor, D. W. 1960. Late Cenozoic molluscan faunas from the High Plains. U.S. Geological Survey Professional Pa- pers 337:1-94. Taylor, D. W. 1966. A remarkable snail fauna from Coa- huila, Mexico. The Veliger 9:152-228, Taylor, D, W. 1970. 4. Western freshwater mollusks. In: Clarke, A. H. (ed.). Proceedings of the American Malaco- logical Union Symposium on Rare and Endangered Mol- lusks. Malacologia 10:33-34. Ta\ lor, D. W. 1983 Status investigation of mollusks. Report to the New Mexico Department of Game and Fish, Con- tract Nos. 519-69-01, 519-69-OlA, 81 p. Thompson, F. G. 1968. The aquatic snails of the family Hy- drobiidae of peninsular Florida, University of Florida Press, Gainesville, FL, xv -I- 268 p. Thompson, F G, 1969. Some h>drobiid snails from Georgia and Florida, Quarterlv Journal of the Florida .\cademy of Science 32:242-265', Thompson, F. G, 1977. The hydrobiid snail genus Marstonia. Bulletin of the Florida State Museum, Biological Sciences 21:113-158. Thompson, F, G, 1979, The systematic relationships of the hvdrobiid snail genus Nymphophilu.s Ta\lor 1966 and the status of the subfamily Nymphophilinae, Malacological Review 12:41-49, Thompson, F, G, 1984. North American freshwater snail genera of the hydrobiid subfamily Lithoglyphinae. Mal- acologia 25:109-141. Thompson, F. G. and J. E. McCaleb. 1978 A new freshwater snail from a spring in eastern Alabama. .American Mid- land Naturalist 100:350-358. Tryon, G. W. 1865. Descriptions of new species of Amniro/a, Pomatiopsis, Somatogyrus. Cahbia, Hydrobia, and Ris- soa. Journal of Conchology 1:219-222. Walker, B. 1901. A new species of Amnicola. The Nautilus 14:113-114. Walker, B. 1908. Pomatiopsis robusta n. sp. The Nautilus 21:97. Wolf, J. 1869 Descriptions of three new species of shells. American Journal of Conchology 5:198. THE NAUTILUS 101(1)33-44, 1987 Page 33 Ecological Differentiation Within the Genus Helisoma (Gastropoda: Planorbidae) in Central Canada Eva Pip Department of Biology University of Winnipeg Winnipeg, Manitoba R3B 2E9 Canada ABSTRACT The distributions of Helisoma anceps. H. campanulatum. H. corpulentum. H. pilslnyi infracarinatum. and H. trivolvis were examined in relation to water body and substrate type, eight water chemistry parameters, Helisoma species diversity (HSD), total gastropod diversity (TGD), and macrophyte diversity (MD). A total of 310 of the 437 sites studied contained Heli- soma. Significant interspecific differences existed with respect to the most frequented types of water bodies and substrates, as well as with respect to ecological tolerance ranges for total dissolved solids, total alkalinity, phosphorus, nitrate, sulphate, dissolved organic matter, and chloride. These differences were reflected in the geographical distributions of the species. Hel- isoma trivolvis was the most widespread species within the study area, and showed the broadest ecological tolerance ranges for the parameters examined, while H campanulatum was the most restricted in terms of habitat parameters, and was found primarily on the Precambrian Shield, Helisoma anceps occupied an intermediate position between these two species. Helisoma corpulentum and H. p. infracarinatum were rare in the study area. Geographical range extensions are presented for H. a. royalense, H. corpulentum. and H. campanulatum. Multiple regression analysis showed that sulphate, dissolved organic matter, and chloride together accounted for ca. 10% of the variability in HSD. HSD was positively correlated with TGD and MD. Significant interspecific differences existed with respect to HSD and MD, but not TGD, Ecological differences between species of the same genus may reduce competition where geographical ranges overlap and may be an important factor in divergent evolution. INTRODUCTION The geographical boundaries of the distributions of sev- eral planorbid species are located in central Canada, an area which also contains a number of important geologic interfaces. The genus Helisoma is of particular interest, since in this region it is represented by all five species [as currently understood (e.g., Clarke, 1981)] native to Canada: H. anceps Menke, 1830, H. campanulatum Say, 1821, H. corpulentum Say, 1824, H. pilsbryi Baker, 1926, and H. trivolvis Say, 1816. Although the ranges of these species overlap in central Canada, preliminary observations have suggested that often only one or two species of this genus may be pres- ent in any given habitat. It was therefore the objective of the present study to determine whether the latter suspicion was indeed true, and if so, whether the distri- butions of individual species could be differentiated with respect to common habitat descriptors such as water body type, bottom substrate, and water chemistry. The ecol- ogy of Helisoma species is thus far known primarily in qualitative terms (e.g.. Baker, 1932, 1936, 1945; Clarke. 1973, 1981); some quantitative data have been reported for the study area by Pip (1978, 1985, 1986). THE STUDY AREA The present study was carried out within the area bounded by 47° and 54°N, and 94° and 106°W. This region is geologically diverse. The Precambrian Shield, which consists largely of granitic and gneissic volcanic rock, dominates the eastern portion of the study area east of Lake Winnipeg. The area west of Lake Winnipeg and including much of Lakes Winnipegosis and Mani- toba is underlain mainly by Ordovician, Silurian, and Devonian sedimentary rocks, particularly limestone and dolomite. West of the latter two lakes these sedimentary rocks are of more recent Triassic and Cretaceous origin. Irregular deposits of Cenozoic shales occur in the south- western portion of the study area. The waters of the Precambrian Shield are typically low in dissolved inor- ganic materials (Pip, 1985), but west of the Shield boundary, total alkalinity and dissolved solids tend to show higher values. MATERIALS AND METHODS A total of 437 sites was examined within the study area during the May-September seasons of 1972-85. Of these, 41% were lakes (> 10 ha), 42% ponds (< 10 ha), 9% rivers ( > 2 m deep), and 8% creeks ( < 2 m deep). Because of environmental heterogeneity, large lakes were sampled at a number of different stations, which were each treated as separate sites. All sites contained water year-round. While heterogeneous substrate types were present at Page 34 THE NAUTILUS, Vol. 101, No. 1 54 "N 48'N I02«W 94°* Figure 1. Distribution of sites where H trivolvis was record- ed. many sites, habitats were classified according to the pre- dominant substrates present where the snails were found. Approximately 11% of the water bodies sampled had primarily granitic bedrock bottom, 2% limestone bed- rock, 1% shale, 16% a mixture of gravel and coarse sand, 27% sand, 6% silt, 19% clay, and 18% mainly organic substrates such as peat. Shallow sites were examined for the presence of mol- luscs and aquatic macrophytes by wading, while deeper waters were sampled by dredging with a rake from a small boat, or, at depths of > 3 m, by using SCUBA. Search time at each site was limited to 1 hr. Plant ma- terial was taken to the laboratory, washed, and exam- ined for additional snails. Only macrophytes that were at least partially submerged were scored. Diversity was defined as the number of species present. Surface water samples were collected for most sites, although at depths of > 3 m a van Dorn sampler was used. The samples were placed on ice in darkness and frozen within a maximum of 48 hr. Samples were ana- lyzed using methods recommended by the American Public Health Association (1971). The pH was measured in situ with a portable pH meter. While most sites were visited only once, approxi- mately 50 locations were resampled at different times of the season and in different years. For these sites, ex- treme low and high water chemistry parameter values were used for statistical analysis. The critical signifi- • H. ANCEPS ANCEPS *« ANCEPS ROYALENSE • HPILSBRYI INFRACARINATUM 94° W Figure 2. Distribution of sites where H. anceps and H. pils- briji infracarinatum were recorded. cance level for all statistical procedures in the present study was p = 0.05. RESULTS Distribution Of the 437 cases examined, 310 contained a record of one or more Helisoma species. Helisoma trivolvis was the most frequently observed member of this genus and was widely distributed throughout the study region (fig- ure 1), occurring at approximately 44% of the sites vis- ited. Clarke (1981) recognized two subspecies of H. tri- volvis in the area under consideration: H. t. trivolvis east of Manitoba (except for a small region in central Sas- katchewan) and H. t. subcrenatum Carpenter, 1856 in Manitoba and to the west. In the present study this zoo- geographical separation was not found to be quite as distinct; both forms occurred in southern Manitoba, al- though H. t. subcrenatum was much more common. These two forms are usually distinguished by differences in axial height (Clarke, 1981), but large series examined at certain sites {e.g., Jackson Lake, near Sidney in south- western Manitoba) showed a wide range of this char- acter, suggesting that further study is needed regarding the status of these two forms. Helisoma anceps was also widely distributed in the study area, although it was less common in the south- western portion (figure 2). It was found at 24% of the sites sampled. While H. a. anceps formed the majority E. Pip, 1987 Page 35 of the occurrences of this species, two populations of H. a. royalense Walker, 1909 were found in eastern Man- itoba (West Hawk Lake in Whiteshell Provincial Park and Bird Lake in Nopiming Provincial Park), repre- senting a westward range extension for this taxon from its previously known boundary in northwestern Ontario. Helisoma campanidatum (figure 3) was distributed primarily on the Precambrian Shield. Occurrences west of the Shield were sporadic, but these constituted south- westward extensions of the range reported by Clarke (1981). The bulk of the populations encountered con- sisted of H. c. campanidatum, although a few occur- rences of H. c. coUinsi Baker, 1939 were noted in the southeastern portion of the study area. This species showed a wide range of morphology and size at different sites. Helisoma pilsbryi infracarinatum Baker, 1932 was infrequently found in the present study (4% of sites sam- pled). It was not seen in the southwestern portion of the study area (figure 2). Helisoma corptdentum was very rare in the study area and was found at only 1% of the sites visited. It was found at a few stations on the Winnipeg River in southeastern Manitoba, and in Whitefish Lake, located on the Manitoba-Saskatchewan border in the Porcupine Provincial Forest, approximately 400 km west of its nearest Winnipeg River occurrence, thus constituting a range extension (figure 3). The Whitefish Lake locus, so far as is known, was not linked by intervening occur- rences to the Winnipeg River populations and may pos- sibly have been the result of accidental transport by human agency, since this lake is frequented by tourist sport fishermen. However, H, corpulentum was com- mon in the lake and therefore must have existed there for some time. Community Diversity The mean number of Helisoma species (HSD) found at the same site was lowest for sites containing H. trivolvis and highest for sites where H. pilsbryi infracarinatum was observed (table 1). HSD was compared for the four most frequent species; one-way analysis of variance was used, since Cochran's C and Bartlett-Box F tests indicat- ed that the homogeneity of variance assumption re- quired for this test was valid. The F ratio between the 54°N 100 km •H. CAMPANULATUM ■ H. CORPULENTUM 'iB'U 102° W 94" W Figure 3. Distribution of sites where H. campanidatum and H. corpulentum were recorded. species was highly significant (table 2), suggesting that the respective species differed in their tendency to occur in communities where other members of the genus were present. Different species pairs were further examined using Duncan's, Student-Newman-Keuls, Tukey's "hon- estly significant difference, " and Scheffe's multiple com- parison procedures (Winer, 1971). The results (table 2) showed that H. trivolvis and H. p. infracarinatum each differed from the other three species with respect to HSD. When the four species were compared with respect to the total numbers of gastropod species recorded at each site (TGD), there were no significant differences between them (table 2). However, comparisons of aquatic Table 1. Mean HSD, TGD, and VID values for sites where each Helisoma species occurred. Values in parentheses are standard errors Species HSD TGD MD N H. trivolvis H. anceps H campanulatum H. pilsbryi injracarinatum H. corpulentum Total sites 1.53 (0.05) 1.73 (0.08) 1.83(0.09) 2.52 (0.20) 2.0 0.95 (0.05) 5.80 (0.20) 5.61 (0.28) 6.36 (0.35) 6.95 (0.76) 5.0 4.58(0.14) 7.39 (0.35) 7.33 (0.45) 11.95(0.52) 9.10(1.29) 9.5 6.96(0.22) 200 113 92 21 4 430 Page 36 THE NAUTILUS, Vol. 101, No. 1 Table 2. Results of one-way analysis of variance and species-pair comparisons with respect to coinmunit\ diversit\ for the four most frequent species. Diversit) parameter Significance of F ratio among four species Species pairs significantK (p < 0.05) different No. of Helisoma spp. at same site (HSD) Total gastropod diversity at same site (TGD) Macrophyte diversit) at same site (MD) F = 11.6 p < 0.001* 2.03 0.11 F P F = 20.1 p < 0,001* H. trivolvis vs. H. campanulattim' -•'^■■' H. trivolvis vs. H. anceps' - H. trivolvis vs. H. p. infracarinatum^-'^'' H. p. infracarinatum vs. H. ancpp.s' - '^ H. p. infracarinatum vs. H. campanulatum'^^-^'* None H. campanulatum vs. H. anceps^''-^* H campanulatum vs. H trivolvi.s^-^'' II campanulatum vs. H p. infracarinatum' - ' Duncan. - Student-New man-Keuls. ^ Tukey "honestly significant difference' ' Scheffe. * Significant difference. macrophyte species richness (MD) yielded a highly sig- nificant F ratio that was largely attributed to differences between H. campanulatum and the other three species (table 2). HSD was highly significantly correlated with TGD (r = 0.56, p < 0.001, N = 430) and with MD (r = 0.32, p < 0.001, N = 430) recorded at the same sites. TGD and MD were also correlated with each other (r = 0.26, p < 0.001, N = 430). Chi-square tests were applied to determine whether any of the species appeared to be associated with others. The results (table 3) showed that most species pairs were not significantly associated. Only two significant positive associations were found: H. trivolvis with H. pilsbryi in- fracarinatum, and H. campanulatum with H. corpu- lenturn. In both cases the second species was rare. Thus the three most common species did not tend to occur with each other at the same site, suggesting that they frequented different habitats within the study area. Be- cause of the low frequencies of H. p. infracarinatum and H. corpulentum. these taxa were excluded from further analysis; what is known of their habitat charac- teristics within the study area has been summarized by Pip (1986). Water Body and Substrate Type The distributions of the three common species were ex- amined with respect to water body type by using 2 x 4 chi-square tests to compare the number of occurrences in each of the four cells for sites where each species was present and those where it appeared to be absent. These groups are henceforth designated as "found sites and "remaining " sites, respectively. "Remaining" sites were used for comparison rather than the overall site sam- pling distribution because the more frequently a species occurs, the more its distribution pattern approaches that of the overall sampling distribution. In the study area both H. anceps and H. campanulatum showed signifi- cantly different distributions at found sites compared to the remaining sites (figure 4). Helisoma anceps was moderately and H. campanulatum strongly more fre- quent in lakes than would be expected from the sam- pling distribution. Helisoma campanulatum also oc- curred the most frequently of the three species in rivers, but was not found in creeks. Helisoma anceps occurred less frequentK in lotic waters. Helisoma trivolvis did not appear to show any distinct preference with respect to water body type. Table .3. Results of chi-square tests for interspecific association. Upper diagonal = chi-square, lower diagonal = p N = 437 H. trivolvis H.p. H. anceps H. campanulatum infracarinatum II. corpulentum H. trivolvis \ 0,04 0,49 H anceps 0.83 \ 1,92 II campanulatum 0.48 0 IT X H. p. infracarinatum < 0.001* 0,19 0,15 II. corpulentum 0.43 0,97 < oor 2,76 0 62 1,71 < 0,01 2,05 8,23 X 0,18 0 67 X * Significant positive correlation. E. Pip, 1987 Page WATER BODY TYPE SUBSTRATE TYPE < o o I- z UJ o cr. 50 40 30 20 10 A H. ANCEPS IN' 106 50-1 N-308 p<0.04 20 -^H I 2^ B^^^ H. CAMPANULATUM H. TRIVOLVIS N« 189 |X^'I.82 P'0.61 N.S. I« LAKES, >I0 ho 2" PONDS, < 10 ho 3« RIVERS, >2 m deep 4= CREEKS, <2 m deep 301 20 10 H. ANCEPS N- 107 X - 13.1 p<0.04 30 20- 10- N'30l 12345678 B| 2 34567 8 50 40 30- 20- 10 H. CAMPANULATUM 1 N* 73 ■ N'335 X ' 32 5 p- type H. trivolms x 3.02 50.7 H. anceps 0 61 x 46 4 H. campanulatiirn < 0 001* < 0.001* x Overall chi-square = 57.5, p < 0,001* B. Bottom substrate type H. trivolvis x 14.4 36.5 H. anceps 0.03* x 20.5 H. cnmpanulatum < 0.001* < 0.001* x Overall chi-square = 47 9, p < 0 001* * Significant difference. that were sampled a number of times. The distributions were divided into six cells for all factors except chloride and sulphate, which were assigned three and four cells, respectively. All three species showed significantly different distri- butions for total dissolved solids at found sites compared to remaining sites (figure 5). Helisonia campanulatum showed the greatest affinity for low values, while H. trivolvis appeared to tolerate the highest concentrations. The differences between these two species can be seen in the similarity of the distributions of the found sites for H. trivolvis and the remaining sites for H. campan- ulatum in figure 5. Total alkalinity showed trends sim- ilar to those seen for total dissolved solids (figure 5). Molybdenum reactive phosphorus was significantly different at found and at remaining sites for all species (figure 6). The greatest proportion of found sites in the lowest concentration class was seen for H. anceps. How- ever, H. campanulatum showed the lowest mean value because H. anceps could also occur at sites with higher values than the maximum seen for H. campanulatum. Helisoma trivolvis showed the highest percentage of sites with high values. Significant differences for combined nitrate and ni- trite were observed at found and at remaining sites only for H. campanulatum and H. trivolvis (figure 6). Heli- soma campanulatum showed the greatest frequencies at the lower end of the concentration scale, while H. trivolvis showed the greatest proportion of higher val- ues. The pH was significantly different at found and at remaining sites only for H. campanulatum (figure 7), which showed the narrowest range of values of the three species. Chloride appeared to be important for H. cam- panulatum (figure 7), which occurred exclusively at sites with low values of this parameter. Chi-square values were very small for the other two species. Sulphate was a significant parameter for H. campan- ulatum and H. trivolvis (figure 8). The former was lim- ited (with one exception) to the lowest concentration cell, while the latter tolerated a broad range of values. Dissolved organic matter was significant for all species Table 5. Results of Kruskal-Wallis one-way analysis of variance and species-pair comparisons with respect to water chemistry parameters for the three most frequent species. Parameter Chi-square, corrected for ties Species pairs significantly different (p < 0,05) pH Total dissolved solids Total alkalinity Molybdenum reactive phosphorus Nitrate and nitrite (Chloride Sulphate Dissolved organic matter 0.38, p = 0.83 62.1, p < O.OOl'* 54.9, p < 0.001* 9.16, p = 0.01* 15.0. p < 0 001* 29.9, p < 0.001* 39.1, p < 0.001* 15.0, p < 0.001* None H. trivolvis vs H. trivolvis vs H. anceps vs. H. trivolvis vs H. trivolvis vs H. anceps vs. H. trivolvis vs H. trivolvis vs H. trivolvis vs H. trivolvis vs H. trivolvis vs trivolvis vs trivolvis vs anceps vs. trivolvis vs trivolvis vs . H. campanulatum'- . H. anceps'-^* H. campanulatum' . H. campanulatum'-'' . H. ancep.t''-^^ H. campanulatum' -•' . H. campanulaliun''- . H. anceps' -' . H. campanulatum'- . H. anceps' -^ . H. campanulatum' - . H. campanulatum'' . H. anceps' -■^'' H. campanulatum' . H. campanulatum' ' . H. anceps'" ' Duncan, * Student- Newman- Keuls. ' Tukey "honestly significant difference' ■' Scheffe. * Significant difference. E. Pip, 1987 Page 39 B < H O UJ B TOTAL DISSOLVED SOLIDS, mg I' H. ANCEPS p<.OI o 5 o rj tM .^ CA A ^ tt O O o o o o o o o o o o o o o o o o o o o o o o H- CAMPANULATUM t ■ 104 N • 90 X* ■ 62.7 p <<*:.ooi fo (ji X. ui ^ •^ a x;=Noi*u> OOoOOOoSqOoOO ooooooog8g§go X • 382 o o o o o 6 o o o o o o 30-1 H. TRIVOLVIS A ZO- ^^^^^ • 349 X '. 26.4 IC- ^^^^^^ N • 196 P < .001 0'^^^^^t^<^— — fout^^ oOoooooqOJJoooo "ooooooo 2S oooo o O o o o o 40 -W 30-^^ B 20-^^L 267 246 I I I XOoOOOOQ °OoOOOOO ro oj .tt ^ ^ o o o °o §§§ o o 01 o o o B TOTAL ALKALINITY, mg T' CaCO, 40 30 A to 10 30 20 10 50 40 A 30 20 10 H. ANCEPS ;• Its N- 114 X- 16.9 P<.OI = Soo 91 X • 90. 1 p o o o -J OB O o o B 20-1 ■, J h 1 i- 135 ,o] I O 1 o o 1 u o k ro o o m o N« 359 ■ Ol Ol O 0< o o O W o o Ol o o CD o o o o o o w o o o 30-1 H. TPIVOLVIS x' A ?0 J L ■ X • 144 • 28.0 10 40-1 O i o o 1 u o 1 ro o o U O N» 193 p < .001 Ol Ol O m o o 4> ^ o o u o o Ol o 01 o o Ol .^ m o o o -g OB Ol O o o B 30- 1 x ■ 104 20 L ■ L N- 257 10- 1 o i o o 1 o 1 ro O O ro Ol O Ol Ol O o o o c» o o o o o 01 o o 01 ^ O" o o o -vj CD o< O o o t Figure 5. Comparisons of sampling distributions for total dissolved solids and total alkalinit\ of found {.\) and remaining (B) sites for the three most frequent species. Horizontal brackets indicate the cells that were combined for chi-square analysis for all species at found us. remaining sites (figure 8). As had been seen for total dissolved solids, again the distribution of re- maining sites for H. campanulatum resembled the dis- tribution of found sites for H. trivolvis. The water chemistry parameters were examined fur- ther for interspecific differences among the three most frequent species. Since several water chemistry param- eters did not show normal sampling distributions, non- parametric multiple comparisons were made for all parameters using Kruskal-Wallis one-way analysis of variance. The results indicated that all parameters ex- cept pH showed significant interspecific differences (ta- ble 5). Each species pair was then compared using Dun- can's, Student-Newman-Keuls, Tukey's "honestly significant difference," and Scheffe s multiple compari- son tests. The results showed significant pair differences for all variables except pH (table .5). Helisoma trivolvis differed significantly from H. campanulatttm and from H. anceps with respect to total dissolved solids, total alkalinity, phosphorus, combined nitrate and nitrite, sul- phate, and dissolved organic matter. Helisoma trivolvis also differed from H. campanulatum with respect to chloride. Helisoma anceps differed from H. campanu- latum with respect to fewer chemical parameters; these were: total alkalinity (most significant) and, at reduced levels of significance, total dissolved solids and sulphate. Page 40 THE NAUTILUS, Vol. 101, No. 1 MOLYBDENUM REACTIVE PHOSPHORUS, mg ^O"^ H. ANCEPS 30-H X" 2.5 X ■ 13.7 N- 116 p <0.02 < O LlI o a: UJ . F^. V oiO»oiji6oibbbbiO« w u i • 2.2 N- 353 Or-— mmwo<**«««>-JOBq ijV <*°'*bbiboiobw oi k. H. TRIVOLVIS i • 3.6 N ■ 197 X ■ 16.1 p <0.0I P--r-MMOI W4>4k(* Oi<»)--J0B55y ""-'''bbibbiocxow u o - o. o ' T T ! -1 1 1 1 1- 1 1 1- T ^ I — MMW CM.;*^ w V o> -4 9 Q mV " o iji o 'a> o o o u) oi I , It , 1 1 , 1 30 A 20 10 B 50 40 30 20 10 30 A 20 10 40 30 20 10 NITRATE*NITRITE, mg I" -^^ H. ANCEPS .^^H^N: IIS X*. 3.46 p • a63 N.S. — :- M M bbiboib«Ooi I I I — I— r Or-— mmo'><'**«o" wO'^bixboibo' T — r I I ffi r-J N di b in O t» % H. CAUPANULATUM i =■ 0.8 X*' 35.8 N"9I p0)r N bwooibwbu'ouio 0.9 253 I I I I I t — I I I p — — MMO<}«**««0)0>S-~J oiO«»baiOoiboiOoib6iObi Figure 6. CJomparisons of sampling distributions for moK bdenum reactive phosphorus and combined nitrate and nitrite of found (A) and remaining (B) sites for the three most frequent species. Horizontal brackets indicate the cells that were combined for chi- square analysis for all species. N.S. = no significant difference. The relative importance of the different water chem- istry parameters could not be defined, since the latter showed a high degree of intercorrelation (table 6). HSD was significantly inversely correlated with dissolved or- ganic matter, total dissolved solids, chloride, and total alkalinity (table 6). Stepwise multiple regression of un- transformed water chemistry parameters on HSD as the dependent variable admitted two parameters into the regression equation, which together accounted for only 4% of the observed variability in HSD: dissolved organic matter (R- = 0.03 after step 1) and chloride (R- = 0.04 after step 2) (p = 0.0001, N = 479). Respective beta values were —0.17 and —0.12, indicating that dissolved organic matter was more important. When HSD and the chemical parameters (e.xcept pH) were log transformed, correlation with total dissolved solids improved substantially when compared with the corresponding values for untransformed variables (table 6), and new significant inverse correlations emerged for sulphate and combined nitrate and nitrite. Apparently these relationships were nonlinear. Stepwise multiple regression of untransformed variables (except pH) ad- mitted sulphate alone into the equation (R- = 0.05, p = 0.020, N = 479). DISCUSSION The results of the present study suggested that the three most common Helisoma species coexist within the study area by frequenting habitats with somewhat different physical and chemical characteristics. Within the study area the major factors that differed between H. trivolvis E. Pip, 1987 Page 41 PH o 40^ H ANCEPS A 30- !■ 8.0 20' N> 116 10- 5 6 30-1 «• 8.0 B 20- 10- N* 343 5 6 30-1 ;. 8.0 10 10 30' H. f CAUPANULATUH . a 1 ^^1 x». 11.5 ^o■ N .93 ^^M p ■ 0.04 10- 1- U^ 10 Figure 7. Comparisons of sampling distributions for pH and chloride of found (A) and remaining (B) sites for the three most frequent species. Horizontal brackets indicate the cells that were combined for chi-square analysis for all species. N.S. = no significant difference. and H. campanulatum were: habitat type, substrate type, total dissolved solids, total alkalinity, phosphorus, ni- trate/nitrite, sulphate, chloride, and dissolved organic matter. Helisoma trivolvis differed from H. anceps with respect to fewer factors; these were: substrate type, total dissolved solids, total alkalinity, phosphorus, nitrate/ni- trite, and sulphate. Helisoma campanulatum and H. anceps differed with respect to the fewest factors: hab- itat type, substrate type, total alkalinity, total dissolved solids, and sulphate. In addition, H. campanulatum tended to occupy habitats that had a much higher macrophyte species richness than those frequented by other species. These observations explained to a large extent the geographical distributions of these species. Helisoma campanulatum, with its significant prefer- ence for lakes and rivers, sand substrates, low water chemistry parameter values, and high macrophyte di- versity, was found mainly on the Precambrian Shield, where such habitat characteristics were common. Heli- soma anceps, with less stringent requirements, occupied a correspondingly broader area. Its significant but re- duced preference for lakes (compared to H. campanu- latum), decreased frequency in lotic waters, and greater tolerance of rather higher water chemistry parameter values was reflected in its greater frequencies in waters west of the Shield, even though it was still much more common in Shield waters, where low parameter values predominated. Because of the reduced number of low-value water chemistry parameter sites west of the Shield, H. anceps and H. campanulatum often occurred together at these sites, and therefore appeared to be associated when a subset of data containing a high proportion of non-Shield sites was considered (Pip, 1978). However, such associ- ation was not apparent on the Shield (Pip, 1985). Helisoma trivolvis showed the widest tolerance ranges for water chemistry values and could occupy all water body and bottom substrate types. The broader variety Page 42 THE NAUTILUS, Vol. 101, No. 1 DISSOLVED ORGANIC MATTER, A UJ o cm LJ a. 279 nm 30 A 20 10 fc H. ANCEPS ; ■ 0.29 1 N* 112 X*' 20.4 p-^ooP'^*> TRIVOLVIS p <0.0I p p O O O P P NOI*o 85% of the cases where H. p. infracarinatum was recorded. The systematic relationship between H. trivolvis and Page 44 THE NAUTILUS, Vol. 101, No. 1 H. p. infracarinatum is unclear. Previous workers {e.g.. Baker, 1928, 1936; Clarke, 1973) have remarked on the problematic amount of variation in morphology of H. p. infracarinatum. In the present study, many occur- rences could be clearly assigned to either H. trivolvis or H. p. infracarinatum, but at several sites both forms were present together with intergrades. Baker (1928) also reported such intergradation from Wisconsin. The two ta.xa may possibly be more closely related than is thought at present. One possibility, suggested by Clarke (1973), is that, if the two taxa are interrelated, H. p. infracarinatum might be a hybrid of H. trivolvis and H. corpulentum, although it was much more common in the present study area than H. corpulentum. This could be explained by its wider ecological tolerance ranges. Another possibility might be that it is indeed a separate species, and the intergrades observed at some sites may be hybrids between it and H. trivolvis. Heli- soma p. infracarinatum might also be a genetic variant of H. trivolvis; populations where the two forms appear to be distinct could be examples of dimorphism. Since, in the study area, H. p. infracarinatum showed a well- defined range of ecological parameters within which it occurred, it might be an ecophenotype of H. trivolvis, manifested by certain genotypes in the population. Whatever the explanation, it must account for the high degree of association between the two taxa. Until more studies are made, the status of H. p. infracarinatum remains uncertain. tance of chemical and spatial variables, Annales Zoologici Fennici 15:155-164. American Public Health Association. 1971. Standard meth- ods for the examination of water and wastewater Amer- ican Public Health Association, New York, 874 p. Baker, F. C, 1928. The fresh water Moiiusca of Wisconsin. Part I. Gastropoda. Bulletin No. 70, Wisconsin Geological and Natural History Survey, Madison, Wisconsin, 507 p. Baker, F. C. 1932. New species and varieties of Helisoma and Gyraultis from Canada. The Nautilus 466-9. Baker, F. C. 1936. The freshwater mollusc Helisoma cor- pulentum and its relatives in Canada. Bulletin No. 79, National Museum of Canada, p, 1-37, Baker, F, C, 1945, The molluscan family Planorbidae. Uni- versity of Illinois Press, Urbana, IL, 519 p. Clarke, A. H. 1973. The freshwater molluscs of the Canadian Interior Basin. Malacologia 13(l-2):l-509. Clarke, A. H. 1981, The freshwater molluscs of Canada. Na- tional Museum of Natural Sciences, Ottawa, Ontario, 446 p. Pip, E. 1978. A survey of the ecology and composition of submerged aquatic snail-plant communities. Canadian Journal of Zoology 56:2263-2279, Pip, E. 1985, The ecology of freshwater gastropods on the southwestern edge of the Precambrian Shield. Canadian Field-Naturalist 99:76-85, Pip, E, 1986. The ecology of freshwater gastropods in the central Canadian region. The Nautilus 100:56-66. Pip, E, and J, M. Stewart. 1976. The dynamics of two aquatic plant-snail associations. Canadian Journal of Zoologv 54: 1192-1205. Winer, B. J. 1971. Statistical principles in experimental de- sign McGraw-Hill, New York, 907 p. LITERATURE CITED Aho, J. 1978. Freshwater snail populations and the equilib- rium theory ol island biogeography. II. Relative impor- THE NAUTILUS 101(l):45-47, 1987 Page 45 The Publication Date of Solarium architae O. G. Costa Kenneth J. Bos§ Arthur S. Merrill Department of Molliisks Museum of Comparative Zoology Harvard Universitv Cambridge, MA 02138. USA Recent and current interest in the gastropod family Ar- chitectonicidae continues unabated with revisions of genera (Bieier, 1984a, 1985a,b, 1986), descriptions of new species (Bieier, 1984b; Merrill & Boss, 1984; Bieier et al., 1985), considerations of the radular apparatus (Bandel, 1984; Boss & Merrill, 1984), the larval shell (Scheltema & Williams, 1983; Bandel et al, 1984), and the anatomy (Haszprunar. 1985a,b) as well as remarks on the geological occurrences (Janssen, 1984; Moroni & Ruggieri, 1984) and zoogeographical ranges (Emerson, 1983; Bieier, 1984a; Melone & Taviani, 1985). It is troublesome to note that conflicting opinion char- acterizes the citation of the original publication and date of the binomen Solarium architae O. G. Costa, a species of architectonicid. With a distribution in the Atlantic Ocean and Mediterranean Sea (Merrill, 1970), this rea- sonably common, off shore benthic species has been re- centU placed in the genus Pscudotorinia (Bieier, 1985b; Bieier et al., 1985). The type-specimen in the Zoological Museum of the University of Naples was destroyed dur- ing World War II (Bieier. 1985b; Melone & Taviani, 1985). Dates given for the original introduction of this taxon in the literature include 1830, 1831, 1839, 1841, 1843, and 1844. These include, chronologically arranged: for 1830, Costa (1841), Aradas and Benoit (1870), Monter- osato (1873), Jeff revs (1885), Locard (1886), Kobelt (1887), Marshall (1887), Watson (1897), Locard (1899), Tomlin and Shackleford (1914), Bayer (1948), Marche-Marchad (1969), Merrill (1970), Turolla (1974), Piani (1980), Ter- reni (1981), Micali and Giovine (1983), Boss and Merrill (1984), and Bieier (1985b); for 1831, Ghisotti (1974); for 1839, Ghisotti (1976), Ghisotti and Turolla (1976). and Melone and Taviani (1985); for 1841, Monterosato (1872), Nobre (1938-40), Priolo (1955), and Bieier et al. (1985); for 1843, Ghisotti (1974); and for 1844, Hanlev (1863), Keen (1971), Abbott (1974), and Sherborn (1923). The title of the publication in which the binomen supposedly appeared for the first time also differs; Ca- talogo de' Testacei viventi nel Golfo di Taranto (Costa, 1841), Catalogo dei Testacei viventi nel grande e pic- colo mare di Taranto (Aradas & Benoit, 1870; Parenzan, no date [post 1976]), Catalogo dei Testacei viventi nel Goljo di Taranto (Turolla, 1974), Catalogo de Testacei viventi nel Piccolo e Grande mare di Taranto (Ghisotti, 1974) and Catalogo sisteniatico dei Testacei viventi nel mare di Taranto (Ghisotti, 1976). There are even inconsistencies in quoting the original Latin description (viz. Turolla, 1974; Ghisotti & Turolla, 1976). Thus, the problem of properly citing this species is compounded by conflicting opinion as to the date of publication of the nomen and the title of the original work in which it appeared; the rarity and obscurity of the publications of O. G. Costa further e.xacerbate this situation. Oronzio-Gabriele Costa (1787-1867) published nu- merous papers in conchology and paleontology, a partial list of which was given b\' Ghisotti (1974). A more com- plete listing is provided in the Catalogue of Scientific Papers (1800-63), Vol. II, compiled and published by the Royal Society of London (1868). A thorough search of original sources shows that Solarium architae was first described and figured in Costa's Fauna del Regno di Napoli. Animali Molli. Classe III. Gasteropodi. Pettini- branchi. p. 5, which was published Ma\ 12, 1841 (Sher- born, 1910, 1937; Erasmo, 1949; Johnson, 1984). There- in, Costa (1841:6) gave the following citation: Solarium Architae, Costa, Catal. de' Test. viv. nel Golfo di Taranto (Atti della R. Accad. delle Scienze vol. \T [sic]. — Rapporto de' lavori della stessa pel 1830, p. 40, n. 15). This referred to a paper that was in press or preparation in the Atti and appeared as: Costa, Oronzio-Gabriele 1844. Catalogo de' testacei viventi nel piccolo e grande mare di Taranto redatto sul sistema di Lamarck. Atti della Reale Accademia delle Scienze, Sezione della Societa Reale Borbonica, Vol. V, Parte II, pp. 13-66, pis. 1-4. His comment, "Rapporto de lavori della stessa pel 1830, p. 40, no. 15 [Report of the work of the same title for 1830] must have been construed by subsequent workers as an actually published paper appearing in the Atti for Page 46 THE NAUTILUS, Vol. 101, No. 1 1830. No such paper of that title appears in the Atti in 1830 or any year until 1844, nor were any recorded by Sherborn (1922, 1932). This was confirmed b\ a search of the Atti as well as by consulting the Indice gene- rale del lavori pubhiicata dal MDCCXXXVII al MDCCCCIII of the Reale Accademia Delle Scienze Fisiche e Matematiche (Classe delta Societd Reale di Napoli) which is an index of all published papers in the variously titled series for those dates. In the 1844 publication of Costa, "Solarium architae nob." appears on p. 48 as the first species of Solarium and no figure is included; this dating of the name was cited in Sherborn (1923) and others as noted above. Although a manuscript of the "Catalogo" or a pri- vately printed paper by Costa may have circulated, much like his rare zoological observations in the Pantellerian Islands (Iredale, 1922), there is no indication of this being the case and no such document has ever been located. Furthermore, authors who cited the year 1830 as the original date for the introduction of S. architae either referred to the "Catalogo in one of its variant titles and/or to the Atti, vol. 3, p. 40, no. 15, first so cited by Monterosato (1873). In summary. Solarium architae Costa, despite nu- merous other datings in the literature, was first described in 1841; the type-specimen is lost; the t\pe-locality is the Gulf of Taranto and the type-figure is the original Costa (1841), pi. 5, figs, a. A, B, C. The species is of particular interest in having such a long lived larval form that its distribution, like a number of teleplanic architectonicids, is amphi-Atlantic. ACKNOWLEDGEMENTS We thank the librarians of the Museum of Comparative Zoology, Harvard University, the Smithsonian Institu- tion, the American Museum of Natural History, the Academy of Natural Sciences of Philadelphia, the Bos- ton Public Library, the New England Book Deposit Li- brary, and the Library of the Rijksmuseum van Na- tuurlijke Histoire in Leiden. Our colleagues, Dr. Riidiger Bieler, Dr. William K. Emerson, Mr. Richard I. Johnson, Dr. Graham Oliver, Dr. Robert Robertson, Dr. Joseph Rosewater, and Dr. A. C. van Bruggen are personally to be acknowledged. We especially thank Dr. R. Tucker Abbott who, in a critical evaluation of the Bieler et al. (1985) manuscript, called attention to a discrepancy of Costa dates in that paper with the dates which appeared in another recent paper by Boss and Merrill (1984). LITERATURE CITED Abbott, R. Tucker. 1974. American seashells: the marine MoUusca of the Atlantic and Patiiic coasts of North Amer- ica, 2nd ed. Van Nostranai and ab\ssal Neogastropoda excluding Turridae (Mollusca, Gastropoda). Bollettino Malacologico, Suppleinento 1:121-296, figs. 282-723. Dall, W. H. 1887. Supplementary notes on some species of mollusks of the Bering Sea and vicinity. Proceedings of the U.S. National Museum 9:297-309, pis. 3, 4. Fabricius, O. 1780. Fauna Groenlandica. Hafnia et Lipsiae. 452 p. Fretter, V. and A. Graham. 1985. The prosobranch molluscs of Britain and Denmark. Pt. 8 — Neogastropoda. Journal of Molluscan Studies, Supplement 15:435-556, figs. 310- 376. Harasewvch, M G. and R. E. Petit. 1986. Notes on the mor- phology of Admctc viridula (Gastropoda: Cancellariidae). The Nautilus 100(3);85-91, figs. 1-11. Harmer, F. W. 1918. The Eocene Mollusca of Great Britain, being supplementary to S. V. Wood's monograph of the Crag Mollusca. Pt. 3. Palaeontographical Society 70(337): 303-461, pis. 33-44, Moller, H. P. C. 1842. Index Molluscoruni Groenlandiae. Naturhistorisk Tidsskrift 4:76-97. Morch, O A L 1852 Catalogus Conchyliorum quae reliquit (. . .) de Yoldi. 1. Hafniae, 172 p. Morch, O. .\. L. 1857. Fortegnelse over Gronlands Bloddyr. In: Rink, H. J. Gronland geographisk og statistik beskriv- et, p. 75-100 [separate, p. 3-28]. Morch, O. A. L. 1868. Fauna Molluscoruni Islandiae. Viden- skabelige Meddelelser fra den naturhistoriske Forening i Kjobenhavn (ll-13):l-43. Morch, O. A. L. 1869. Catalogue des Mollusques du Spitz- berg. Memoires de la Societe Malacologique de Belgique 4:7-32 [separate, p. 3-28]. Morch, O. A L. 1877. Mollusca In: Rink, H. Danish Green- land, its people and its products. S. King, London, p. 435- 442. Pilsbrv, H. A. 1938. On the histor\ and status of Lora Gistel. The Nautilus 51(4):115-118. Sars, G. O. 1878. Mollusca regionis arcticae Norvegiae. Brog- ger, Christiania, 466 p. Sneli, J. -A. and O. Stokland. 1986. On the taxonomical status of Tritonium viridulum Fabricius, 1780 (Gastropoda: Cancellariidae). The Nautilus 100(4):121-124, figs. 1-7. Sowerby, G. B., I. 1832. In: Broderip, W. J. and G. B. Sow- erby. [Characters and descriptions of new species of Mol- lusca and Conchifera collected by Mr. Cuming] Proceed- ings of the Zoological Society of London 17:50-61. Wood, W. 1828a. Index Testaceologicus; . . . [third edition of this title, but called "Second Edition, corrected and revised " on title page]. London, p. i-xxii, [-1- 1,] 1-212, 38 pis. Wood. W. 1828b. Supplement to the Index Testaceologicus; or a catalogue of shells, British and foreign. London, p. i- iv, [-1- 1,] 1-.59, 8 pis. THE NAUTILUS 101(1):50, 1987 Page 50 News and Notices SMITHSONIAN FUNDS FOR MALACOLOGY STUDENTS The Division of Mollusks, Department of Invertebrate Zoology, National Museum of Natural History, Smith- sonian Institution announces the availability of two fel- lowships to be awarded to graduate students of system- atic malacology. 1. Rosewater Fellow Award (up to $500) 2. Smithsonian-COA Fellow Award (up to $1,000) These awards provide support for students conducting systematic studies of Mollusca (leading to publication) who require access to collections and libraries of the Division of Mollusks, National Museum of Natural His- tory. Funds can be used for travel, subsistence, and re- search costs. Interested students should submit a succinct proposal (1-2 pages), including budget with indication of any matching funds, and a supporting letter from faculty advisor(s). Application deadline is March 1, 1987. Awards will be announced on April 1, 1987. TENTH INTERNATIONAL MALACOLOGICAL CONGRESS The Tenth International Malacological Congress will be held from August 27 to September 2, 1989, in Tiibingen, Southwest Germany. Papers dealing with any aspects of malacology are invited for oral or poster presentation. Malacologists wishing to attend should be prepared to submit provisional titles of papers, together with one or two sentences exposing the questions dealt with therein (instead of an abstract for which it would be too early), before September 30, 1988. Address inquiries to the current president of UNITAS MALACOLOGIA: Dr. Claus Meier-Brook Tropenmed. Inst. d. Univ. Wilhelmstr. 31 D-7400 Tubingen Federal Republic of Germany INSTRUCTIONS TO AUTHORS THE NAUTILUS publishes papers on all aspects of the biology and systematics of mollusks. Manuscripts de- scribing original, unpublished research as well as review articles will be considered. 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Marine Biological Laboratory LIBRARY MAY 7 1987 3 Woods Hole, Mass. i— ^— — — ^— — ir-w^ii I Mil iwiii.^J s. I EDITOR-IN-CHIEF Dr. M. G. Harasewych Division of Mollusks National Museiini of Natural Histor\ Smithsonian Institution Washington, DC; 20560 ASSOCIATE EDITOR Dr. R. Tucker Abbott American Malacologists, Inc. P.O. Bo.\ 2255 Melbourne, FL 32902 CONSULTING EDITORS Dr. William K. Emerson Department of Living Invertebrates The American Museum of Natural History New York, NY 10024 Mr. Samuel L. H. Fuller 1053 Mapleton .^ venue Suffield. CT 06078 Dr. Robert Hershler Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC 20560 Dr Richard S. Houbrick Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC: 20560 Mr. Richard I. Johnson Department of Mollusks Museum of Comparative Zoology Harvard University Cambridge, MA 02138 Dr. Aurele La Rocque Department of Geology The Ohio State University C:oliitnl)us. 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Box 3430 Silver Spring, MD 20901 THEt^NAUTILUS CONTENTS ' Marine Biological Laboratory LIBRARY MAY 71987 Woods Hole, Mass. Volume 101, Number 2 April 28. 1987 ISSN 0028-1344 Paula M. Mikkelsen and Paul S. Mikkelsen Redescription of Acteocina recta and A. lepla, two species of cephalaspidean gastropods from the western Atlantic 51 James F. Quinn. Jr. A revision of the Seguenziacea Verrill, 1884 (Gastropoda: Prosobranchia). II. The new genera Hadrocontis, Rotellenzia, and Asthelys 59 Geerat J. Vernieij, Richard B. Lowell, Linda J. Walters, and Jessica A. Marks Good hosts and their guests: Relations between trochid gastropods and the epizoic limpet Crepidula adiinca 69 Charles W. Randall and Robert F. Martin Distribution, abundance, and movement patterns of shoreline chitons of the Caribbean coast of Mexico 75 Richard S. Houbrick Transfer of Cerithiopsis crystallina Dall to the genus Varicopeza Griindel, famih Cerithiidae (Prosobranchia: Gastropoda) 80 H. Lee Fairbanks Identity and status of Philomycus pennsylvanicus Pilsbry, 1894 (Gastropoda: Pulmonata: Philom\cidae) 86 Perry A. Peon The diet and feeding behavior of Caduhis tolmiei Dall, 1897 (Scaphopoda: Siphonodentaiioida) 88 W. Bruce Saunders, Larry E. Davis, and Ron L. knight Sympatric species of Nautilus (N. pompilius and N. scrobiculatus) in the .\dmiralty Islands, Papua New Guinea 93 News and Notices 100 THE NAUTILUS 101(2):51-58, 1987 Page 51 Redescription of Acteocina recta and A. lepta, Two Species of Cephalaspidean Gastropods from the Western Atlantic Paula M. Mikkelsen Paul S. Mikkelsen Harbor Branch Oceaiiographic Institution, Inc. 5600 Old Dixie Highway Ft^ Pierce, FL 33-150-9719, USA ABSTRACT Acteocina recta (Orbigny, 1841) and A. lepta Woodring, 1928, both from the Western Atlantic, are redescribed on the basis of type material and other specimens from museums and pri- vate collections. Acteocina recta, for which a lectotype is des- ignated, is characterized by its generally small (1-2 mm), thin shell, spiral striae, low spire, double-keeled shoulder, and ta- pered protoconch, indicative of planktotrophic larval devel- opment. It ranges from eastern Florida to Texas, and through- out the Caribbean to Brazil. Acteocina lepta was originally described as a Plio- Pleistocene fossil from Jamaica. It is thick- shelled and spirally striate, with a low spire, double-keeled shoulder, and bulbous protoconch, indicative of non-plankto- trophic larval development; adults are 2-5 mm in length. In the Recent fauna, it ranges from Bermuda and North Carolina to Louisiana, and throughout the Caribbean to Brazil INTRODUCTION In the course of studying collections of Western .Atlantic Acteocina species, numerous niorphot\ pes have been dis- tinguished. Three of these, A. canaliculata (Say, 1826), A. candei (Orbigny, 1841), and A. atrata Mikkelsen and Mikkelsen, 1984, have already been recognized as valid species (Mikkelsen & Mikkelsen, 1984). Two others. A, recta (Orbigny, 1841 ) and A. lepta Woodring, 1928, have often been misidentified in collections, and have fre- quently been confused with each other. The present pa- per redescribes the last two species on the basis of type specimens and other live- and dead-collected material, and redefines their geographic distributions. MATERIALS AND METHODS Dried and wet-preserved specimens from the following museums and private collections were utilized to deter- mine geographic and bathymetric distributions of these species: ANSP, Academ\' of Natural Sciences of Philadelphia, Philadelphia, PA. BM(NH), British Museum (Natural History), London. Coovert Collection, Gary A. Coovert, Dayton, OH. Edwards Collection, Amy L. Edwards, LTniversitv- of Georgia, Athens, GA. Finlay Collection, C. John Finlay, Palm Ba\', FL. FSBC 1, Florida Department of Natural Resources, Bureau of Marine Research, St. Petersburg, FL. HMNS, Houston Museum of Natural Science, Hous- ton, TX. IRCZM, Indian River Coastal Zone Museum, Harbor Branch Oceanographic Institution, Ft. Pierce, FL. Keeler Collection, James H. Keeler, Tallahassee, FL. Lee Collection, Harry G. Lee, Jacksonville, FL. LIU, Southampton College (Long Island University), Southampton, NY. MCZ, Museum of Comparative Zoology, Harvard Uni- versity, Cambridge, MA. MORG, Museu Oceanografico, Rio Grande, Brazil. Redfern Collection, Colin Redfern, Boca Raton, FL. UNC-IMS, Institute of Marine Sciences, University of North Carolina, Morehead City, NC. USNM, National Museum of Natural History, Smith- sonian Institution, Washington, DC. Williams Collection, Peggv Williams, Sarasota, FL. Worsfold Collection, Jack Worsfold, Freeport, Baha- mas. In "Material Examined" sections, an "L" following the number of specimens indicates that at least one of the specimens in the lot was live-collected and contained soft parts; an "E indicates that all specimens w ere empty shells. Shell terminology is after Smith (1967:758-760) and Knight (1952:7-9); radular terminology is after Bertsch (1977:110-111). Radulae and gizzard plates were ex- tracted and prepared for light microscopy using the method previouslv described (Mikkelsen & Mikkelsen, 1984; Mikkelsen, 1985). Page 52 THE NAUTILUS, Vol. 101, No. 2 Figures 1-4. Acteocina recta. 1. Syntypes, BM(NH) 1854.10.4.16. Left 1.41 mm (lectotype), center 1.S5 mm (paralectotype), right 1.76 mm (paralectotype). 2. Adult shell from off Ft. Pierce, Florida, 1.62 mm. 3. Specimen in figure 2, oblique view of p. M. Mikkelsen and P. S. Mikkelsen, 1987 Page 53 SYSTEMATIC RESULTS Genus Acteocina Gray, 1847 Acteocina recta (Orbigny, 1841) (figures 1-6) Bulla recta Orbigny, 1841:131. 1842: pi 4 bis, figs, 17-20. Material examined: Syntypcs: 3 specimens [lectotype (1.41 mm), 2 paralectotvpes (1.85 mm, 1.76 mm frag- ment)], BM(NH) 1854.10.4.16. Other material: 632 specimens (ANSP, HMNS, LIU, MCZ, MORG, USNM, Worsfold Collection), including the follovsing as repre- sentative \oucliers: Florid.\: Oi^ Ft. Pierce: IIL, IRCZM 065:02411, 065:M0063 (microslide with radula and giz- zard plates); 2L, USNM 859080; 2L, USNM 859081; 6L, ANSP A11629; 6L, BM(NH) 1986149 (including mi- croslide with radula and gizzard plates). — Bahia Honda Key: IE, USNM 358296— Louisiana: South Pass: 30E, HMNS 9222.— Texas: Southeast of Freeport: 15L, HMNS 8122.— North of Port Isabel: 9E, HMNS 8151 —Greater Antilles: Northwestern Cuba: IE, USNM 358229.— Cavman Islands: IE, ANSP 295944 —Haiti: 2E, USNM 859087.— Bahamas: North of Abaco: IE, MCZ 294082.— Lesser Antilles: British Virgin Islands: 5L, ANSP 351676.— Antigua: IE, USNM 859088; 6E, ANSP 8220.— West Grenada: IE, ANSP 296955 —Central America: Belize: 6E, ANSP 285386— Guatemala: IE, ANSP 76460.— Panama: 2E, ANSP 200034— South America: South Bahia, off eastern Brazil: IE, MORG 20.110 (spec- imen subsequently lost). Original description: Orbignv (1841:131) originally de- scribed Bulla recta from the Antilles as "oblong, straight, cylindrical, uniform throughout its length, slender, frag- ile, shining, displaying nevertheless, under magnifica- tion, signs of transverse striations. Spire projecting, very short, strongly channeled at the suture. Aperture linear, straight behind, suddenK enlarging at the front, colu- mella simple, without teeth. Color uniformly white." He distinguished the species by its strongly cylindrical shape and spiral striations, and described its protoconch as "transverse to the spiral axis," or hyperstrophic. Type material: The type material of Bulla recta (figure 1) consists of three specimens, all originally glued to a strip of black paper. The smallest specimen (1.41 mm length), still glued to the paper, has an intact protoconch, highly evident spiral striae, and has retained its trans- parency. A second specimen (1.85 mm length), although more worn than the first, shows fine spiral striae and a slightly glossy surface. The third specimen (1.76 mm length), consisting of a fragmented body whorl, is of a size and shape to be positively identified as A. recta. The latter two specimens are loose, but have glue and paper remnants on their dorsal surfaces. The locality given on the label is "Antilles." The smallest syntype (figure 1, left), being the best representative of the species-specific characters, is here designated as lectotype for Acteocina recta. The re- maining two specimens (figure 1, center and right) are designated as paralectotypes. Diagnosis: Teleoconch thin-walled, cylindrical, with fine spiral striae throughout its length. Shoulder with rounded keel adjacent to suture and sharp keel at shoulder; 2 keels separated by concave trough. Protoconch tapered, in- dicating planktotrophic development. Lateral radular teeth each with a wing-like expansion bearing a single row of denticles; rachidian teeth with 3 robust denticles per half. LInpaired gizzard plate T-shaped. Distribution: St. Lucie County, eastern Florida, to southern Texas; Bahamas; Greater and Lesser Antilles; Atlantic Panama; southeastern Brazil. Recorded living at depths of 33-44 m; empty shells collected from 2-128 m. Description: The orthostrophic, dextral teleoconch of Acteocina recta (figure 2) is cylindrical with nearly par- allel sides, and has fine spiral striae. Two to three whorls are typical of adult (1-2 mm) specimens. The aperture is narrow (i.e.. less than Vi of the shell width), paralleling the side of the body whorl, and flaring anteriorly. The columella, although "toothless" as Orbigny (1841) stated, bears a single weak fold. The shell walls are thin and transparent in fresh material. The shoulder (figure 3) is double-keeled; a sharp keel at the shoulder is separated from a rounded keel adjacent to the suture by a narrow concave trough of var\ ing depth. The rounded keel and concave trough are crossed by strong axial wrinkles. The spire is nearK flat in specimens under 2 mm; in larger individuals (to 2.5 mm), spire height is typically less than 20% of the shell length. The periostracum is thin and transparent. The smooth, hyperstrophic protoconch (figure 4) is tapered and similar in shape to that of Acteocina ca- naliculata (Say, 1826), which was shown to indicate planktotrophic larval development (Mikkelsen & Mik- kelsen, 1984: fig. 3, e-g). The radular formula of Acteocina recta is 1-R-l, with 8-14 radular rows in adults (n = 6). The rachidian teeth (figure 5, R) are centrally notched, with each rounded half bearing three (rarely four) sharply pointed, robust denticles. The lateral teeth (figure 5) are sickle-shaped and unicuspid, with the cusp bearing a wing-like expan- sion supporting one row of 4-6 denticles. A blunt basal tubercle is present for articulation with adjoining lateral teeth. Three calcareous gizzard plates are present (figure 6): a "pair of non-identical, but similarly elongated, plates shoulder. Scale bar = 40 nm. 4-. Specimen in figure 2, protoconch showing tapered, planktotrophic-type morphology. Scale bar 40 ^m. Page 54 THE NAUTILUS, Vol. 101, No. 2 Figures 5-8. Radulae and gizzard plates. Acteocina recta: 5. Two rachidian (R) and two lateral teeth. Scale bar = 10 ^m. 6. Gizzard plates. Scale bar = 100 /im. A. lepta: 7. Two ra- chidian (R) and two lateral teeth. Scale bar = 10 ^m. 8. Gizzard plates. Scale bar = 100 txm. opposes a larger "unpaired" plate. The unpaired plate is most dorsal in the crawling animal and is distinctly T-shaped (n = 5). Remarks: Since its original description, Acteocina recta has appeared in the literature mainly as an undiscussed member of various Recent faunal lists {e.g., Gabb, 1873, 1881; Morch, 1875; Guppy, 1876; Arango y Molina, 1878; Dall, 1889, 1903b; Smith, 1890; Ihering, 1915; Maury, 1922; Johnson, 1934; Lange de Morretes, 1949; Coomans, 1963; Marcus & Marcus, 1964; Abbott, 1974). One such Bermudan record (Peile, 1926) has been found, by ex- amination of voucher specimens (ANSP 141560; see A. lepta synonymy), to be A. lepta. Pilsbry (1895) and Ver- rill and Bush (1900) figured A. recta, gave brief synon- ymies, and/or reiterated previous descriptions. In the fossil literature, A. recta has been recorded from the Miocene of Santo Domingo (Gabb, 1873; Maury, 1917, 1922), the Oligocene of Jamaica (Dall, 1903a), and the Miocene and Pliocene of Costa Rica (Olsson, 1922, and Gabb, 1881, respectively). None of these previous rec- ords, with the e.xception of Peile (1926), have been ver- ified through specimen examination, although all fall within the verified geographic range of the species. Some workers (Dall, 1889; Maury, 1917; Olsson, 1922; Woodring, 1928) have cited Tornatina coixlacrijma Guppy, 1867, from the Jamaican Miocene, as a synonym (in whole or in part) of Acteocina recta. However, the neotype of T. coixlacrijma (I'SXM 369322, designated by Woodring, 1928) differs markedly from A. recta in conchology in having a larger, more robust shell with a deeply channeled suture and bulbous protoconch. Caution must be used in dealing with small specimens of Acteocina candei (Orbigny, 1841), which are often thin-shelled, low-spired and lack distinct subsutural sculptural bands, thus resembling specimens of A. recta. The former species may be distinguished in these cases by the absence of spiral striae. Acteocina lepta Woodring, 1928 (figures 7-13) Acteocina lepta Woodring, 1928:121, pi. 2, fig. 5. Retusa candei (Orbigny, 1841). Warmke and Abbott, 1962: 143, pi. 27g; Rice and Kornicker, 1965:129, pi. 8, fig. 10. Acteocina recta (Orbigny, 1841). Peile, 1926:85 [ref. ANSP 141560 (voucher specimens)]. Tornatina candei (Orbigny, 1841). Rehder, 1981:635, fig. 356. ? Tornatina cijlindrica Emmons, 1858:181, fig. 182. Material examined: Holotype: 3.78 mm, USNM 369320. Other material: 2,302 specimens (ANSP, FSBC I, HMNS, IRCZM, LIU, MCZ, MORG, UNC-IMS, USNM, and collections of Coovert, Edwards, Finla\ , Keeler, Lee, Redfern, Williams, Worsfold) including the following as representative vouchers: Bermuda: 24E, ANSP 141560. — North Carolina: Off Cape Hatteras: IL, USNM 329930.— Off Cape Lookout: 3L, UNC-IMS 9858.1-3; 2L, IRCZM 065:02056, 065:M0057 (microslide with rad- ula and gizzard plates). — South Carolina: IE, IRCZM 065:01930. — Georgia: IE, Edwards Collection. — Flori- da: Off St. Lucie County: IE, FSBC I 26258.— Off Palm Beach: 3E, ANSP 359158.— Off Miami: 9E, USNM 859089.— Key Largo: 18E, ANSP 336230 —Kev West: 2L, USNM 859090.— Off Sanibel: IL, MCZ 245062.— Off Tampa: 2E, ANSP 358045.— Off Cape San Bias: 3E, USNM 323422.— Louisiana: Off Cameron: 3E, HMNS 8161. — Greater Antilles: Northern Cuba: 2E, Finlay Collection.— Southeastern Cuba: IE, USNM 383696 — Jamaica: 27E, USNM 859091.— Cayman Islands: 5E, ANSP 296098.— Dominican Republic: 2E, USNM 807258.— Western Puerto Rico: IE, USNM 859092.— Bahamas: Greater Abaco Island: 3E, ANSP 357901.— Bimini Islands: 9E, USNM 859093— Andros Island: 548E, USNM 859094.— Lesser Antilles: Barbados: 2E, USNM 500361. — Central America: Yucatan: IE, USNM 667674. — South America: Northern Brazil: 8E, MORG 22.365. Original description: Acteocina lepta was originally described as a fossil from Bowden, Jamaica: "shell small, slender, tightly coiled, subcylindrical, bod) whorl ta- pering gently at base. Nuclear whorls forming a large tip. Anal fasciole concave, bearing axial puckers, bound- ed by sharp-edged ridges. Middle of outer lip slightK constricted. Umbilical groo\e narrow , deep (Woodring, 1928:121). Although presumed by Woodring to be Late Middle Miocene, Blow (1969) and Robinson and Lamb (1970) have shown the type locality to be Pliocene to Early Pleistocene in age. p. M. Mikkelsen and P. S. Mikkelsen, 1987 Page 55 Figures 9-13. Acteocina lepta. 9. Holotype, 3.78 mm, USNM 369320. 10. Adult shell from Cuba, 4.50 mm. 11. Specimen in figure 10, oblique view of shoulder. Scale bar = 100 ^m. 12, 13. Specimen in figure 10, protoconch showing bulbous, non- planktotrophic morphology. Scale bars = 40 ^m. Page 56 THE NAUTILUS, Vol. 101, No. 2 Type material: The holotype of Acteocina lepta (figure 9), although worn, is in generally good condition and has an intact protoconch. A bored hole with worn edges is on the ventral surface of the body whorl. No sculptural details can be discerned on the shell surface, e.xcept for distinct a.xial wrinkles on the shoulder. Diagnosis: Teleoconch thick-walled, porcellaneous, cy- lindrical, fineK spirally striate throughout its length. Shoulder w ith rounded, elevated keel adjacent to suture, plus sharp keel at shoulder, separated by a slightly con- cave, axially wrinkled area. Protoconch well-protruded and bulbous, indicating non-planktotrophic develop- ment. Lateral radular teeth each with a wing-like ex- pansion bearing a single row of denticles. Rachidian teeth with robust base, median buttress, and fine denticles. Unpaired gizzard plate heart-shaped. Distribution: Bermuda; North Carolina to the Florida Keys and to Louisiana; throughout the Caribbean, in- cluding the Greater and Lesser Antilles, the Bahamas, Yucatan, and to northern Brazil. Plio-Pleistocene to Re- cent. Recorded living at depths of 7-226 m; empty shells collected from 2-457 m. Description: The orthostrophic, dextral teleoconch of Acteocina Icpta (figure 10) is c\lindrical, with nearly parallel sides, and is finely spirally striate. The shells are rather thick, giving a porcellaneous appearance to av- erage-sized (3-5 mm) specimens. The columella bears a single strong fold. In live-collected or fresh-dead mate- rial, a thin, light Nellow periostracum is evident. The shoulder (figure 11) is sharply keeled, with a second elevated keel just below the suture. Between these keels, the rather wide slope is slightly concave and axialK wrin- kled The spire is generally very low, usually 7-9% (max- imum 13%) of the total length. The smooth, hyperstrophic protoconch (figures 12, 13) is typically well-protruded above the first teleoconch whorl. It is bulbous and similar in shape to that of Ac- teocina atrata Mikkelsen and Mikkelsen, 1984 (Mikkel- sen & Mikkelsen, 1984: fig. 8, e-g). This type of proto- conch has been observed in at least ten species of cephalaspids in the Western Atlantic alone, and is known in two, including A. atrata, to reflect capsular meta- morphic (= direct) larval development (personal obser- vation). However, some recent workers (Turner et al., 1985) have surmised that prosobranch protoconchs of this same general size and morpholog\ indicate lecitho- trophic (= non-feeding planktonic) development. Given this apparent discrepancy, the best we can infer from the available evidence is that A. lepta probabK' has non- planktotrophic development. The radular formula of Acteocina lepta is 1-R-l with about 16 rows in adult specimens (n = 3). The rachidian teeth (figure 7, R) are centrally notched with each half bearing 6-9 fine, sharply pointed denticles. The base of the rachidian is robust (staining dark pink in acid fuchsin) and extends along the center of the tooth in the form of a triangular buttress. The apex of this buttress meets the approximate center of the indentation between the two halves of the tooth. The lateral teeth (figure 7) are sickle- shaped and unicuspid, with the cusp bearing a wing-like expansion supporting one row of 10-12 denticles. A blunt, basal tubercle is present for articulation with adjoining lateral teeth. The three subequal calcareous gizzard plates (figure 8) consist of a rounded heart-shaped "unpaired" plate, and two elongated, nonidentical "paired" plates (n = 3). Remarks: Acteocina lepta has been cited in the liter- ature only once since its original description, from the Middle Miocene of Santa Rosa, Veracruz, Mexico (Per- rilliat, 1974). It has not been previously recorded as part of any Recent fauna. The results of our previous work on the type species A. canaliculata (see Mikkelsen & Mikkelsen, 1984) allow the genus Acteocirm to be used for this, and other, extant species. Numerous museum lots of Acteocina lepta ha\e been misidentified as A. recta. This may stem from a mis- leading statement by Woodring (1928:121) who origi- nally described A. lepta as "the Bowden representative of and "smaller than" the living A. recta. Acteocina lepta is similar in general appearance to Tornatina persimilis Dall, 1895, from the Oligocene of Florida, as noted by Woodring (1928). However, the latter species (holotype, 3.02 mm, USNM 112607) has a tapered, planktotrophic-type protoconch and completely lacks spiral striations. The original figure of the North Carolina Miocene species Tornatina cylindrica Emmons, 1858, is ex- tremely similar to Acteocina lepta. A search for type material of Emmons species has been unsuccessful, mak- ing determination of protoconch morphology and other critical features impossible. The original description is inadequate to distinguish it from other species, therefore, T. cylindrica must be considered a nomen dubium. Acteocina lepta bears close resemblance to Tornatina liratispira E. A. Smith, 1872, the sole conchological dif- ference being protoconch morpholog\. The four syn- types of the latter species [BM(NH) 1860.5.2.29] were examined; one of the four specimens was found to be A. candei (Orbigny). As no live-collected specimens of T. liratispira were available for dissection, radular and giz- zard plate morphologies remain unknown. Determina- tion of its proper generic placement and relationship with A. lepta must therefore await further study. Tornatina liratispira is here reported from the Bahamas, the Great- er and Lesser Antilles, and the northern coast of Brazil, at depths ranging from 35 to 106 m. Acteocina lepta has been figured several times in the literature as A. candei (Orbign\) (Warmke & Abbott, 1962; Rice & Kornicker, 1965; Rehder, 1981). DISCUSSION Morphological characteristics of Acteocina recta and A. lepta are summarized in table 1. Extreme caution is advised when identifying speci- mens of these and other species of Acteocina sensii lato. Key characters include shell shape and general sculpture. p. M. Mikkelsen and P. S. Mikkelsen, 1987 Page 57 Table 1. Distinguishing characteristics of Actcocina recta and A. lepta. A. recta A lepta Shell length Shell shape Spire height Sutural keel Trough between shoulder and sutural keels Shell walls Columella Periostracum Protoconch Inferred type of larval development Lateral tooth denticles Rachidian tooth denticles Rachidian buttress Unpaired gizzard plate 1-2 mm c\ lindrical, parallel sides fiat to low (<20?'c) rounded narrow, concave thin, transparent weak fold thin, transparent tapered planktotrophic 4-6 3 per half not present T-shaped 3-5 mm c\ lindrical, nearK parallel sides flat to low (7-13'7) sharp, elevated wide, concave thick, porcellaneous strong fold thin, light yellow bulbous non-planktotrophic 10-12 6-9 per half present heart-shaped shoulder sculpture, type of protoconch, radula, and giz- zard plates. Spiral striae are often exceedingly fine and may be imperceptible in wet {i.e., alcoholic) specimens; momentary dry ing of the shell surface is freciuently nec- essary for examination. Worn shells, especially those with eroded surfaces and/or missing or worn protoconchs are particularly problematic. All species of Acteocina (and other closely related genera) that we have examined thus far are conchologically separable. However, these con- chological distinctions may be in the protoconch only. A thorough understanding of species-specific shell char- acters, in combination with radular and gizzard plate characteristics, is essential. ACKNOWLEDGEMENTS The time required to conduct this work was generously allowed by Dr. Robert W. Virnstein (Seagrass Ecosystems Analysts, Ft. Pierce, FL) and Mr. John E. Miller [Harbor Branch Oceanographic Institution (HBOI), Ft. Pierce, FL]. Our thanks extend to the following for arranging examination of museum specimens entrusted to their care: the late Dr. Joseph Rosewater, Mr. Frederick J. Collier, and Mr. Warren C. Blow (USNM); Dr. John Taylor and Ms. Kathie Way [BM(NH)]; Dr. Robert Rob- ertson and Ms. Mary A. Garback (ANSP); Dr. Kenneth J. Boss, Dr. Ruth D. Turner, and Ms. Carey Westermann (MCZ); the late Dr. Thomas Pulley and Ms. Constance Boone (HMNS); Mr. Hugh J. Porter (UNC-IMS); Dr. E. de C, Rios (MORG); Mr. William G. Lyons (FSBC I); and Ms. Amy L. Edwards (LIU, and University of Geor- gia, Sapelo Island). We also thank the following for al- lowing examination of specimens in their personal col- lections: Gary A. Coovert (Davton, OH), C. John Finlay (Palm Bay, FL), James H. Kee'ler (Tallahassee, FL), Har- ry G. Lee (Jacksonville, FL), Colin Redfern (Boca Raton, FL), Peggy Williams (Sarasota, FL), and Jack Worsfold (Freeport,'Bahamas). P. A. Linley (HBOI) and R. Bieler [Smithsonian Marine Station at Link Port (SMSLP), Ft. Pierce, FL] read and commented on various versions of the manuscript. J. Piraino (SMSLP) and T. Smoyer (HBOI) assisted with SEM and light photography, respectively. K, Metzger and C. Browder (HBOI), and the staff of the Division of Mollusks, USNM, assisted in literature ac- quisition. This is Contribution Number 546 of Harbor Branch Oceanographic Institution, Inc. LITERATURE CITED Abbott, R. T. 1974, American seashells, 2nd ed. Van Nostrand Reinhold Company, New York, 663 p., 24 pis, Arango y Molina, R, 1878, Contribucion a la fauna malaco- logica Cubana. Imp. de G, Vlontiel y Comp., Habana, 280 text p. -I- 35 index p, Bertsch, H. 1977, The Chromodoridinae nudibranchs from the Pacific coast of America, Part I, Investigative methods and supra-specific taxonomy. The Veliger 20(2):107-118. Blow, W. H. 1969. Late Middle Eocene to Recent planktonic foraminiferal biostratigraphy. In: Bronnimann, P. and H. H. Renz (eds. ). Proceedings of the First International Con- ference on Planktonic Microfossils, Geneva, 1967, E, J, Brill, Leiden, 1:199-421, 54 pis, Coomans, H. E. 1963, The marine MoUusca of St, Martin, Lesser Antilles, collected by H, J, Krebs. Studies on the Fauna of Curacao and Other Caribbean Islands 16:59-87, Dall, W, H, 1889. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U.S. Coast Survey Steamer "Blake," Lieut-Commander C. D. Sigsbee, U.S.N,, and Commander J, R, Bartlett, U.S,N,, commanding X.XIX Report on the Mollusca Part II Gas- tropoda and Scaphopoda, Bulletin of the Museum of Com- parative Zoology at Harvard College 18:1-492, pis, 1-40, Dall, \V, H. 1895, Diagnoses of new Tertiary fossils from the southern United States, Proceedings of the United States National Museum 18(1035):21-46, Dall, W, H 1903a, Contributions to the Tertiary fauna of Florida w ith especial reference to the Silex Beds of Tampa and the Pliocene beds of the Caloosahatchie [sic] River , , , Part \'I, Concluding the work. Transactions of the Wagner Free Institute of Science of Philadelphia 3:1219-1654, pis, 48-60. Page 58 THE NAUTILUS, Vol. 101, No. 2 Dall, W. H 1903b. .\ preliminar)- catalogue of the shell- bearing marine niollusks and braehiopods of the south- eastern coast of the United States, with illustrations of many of the species. Reprint, to which are added 21 plates not in the edition of 1889. United States National Museum Bulletin 37, new edition, 232 p., 95 pis. Emmons, E. 1858. Report of the North Carolina Geological Survey. .Agriculture of the eastern counties; together with descriptions of the fossils of the Marl Beds. Bulletins of .•\merican Paleontology 56(249):230 p. Gabb, VV. M. 1873. [On the] Topograph) and geology of Santo Domingo. Transactions of the American Philosophical So- ciety 15:49-259, 2 maps. Gabb, W. M. 1881. Descriptions of new species of fossils from the Pliocene clay beds between Limon and Moen, Costa Rica, together with notes on previously known species from there and elsewhere in the Caribbean area. Journal of the Academy of Natural Sciences of Philadelphia 8:349-380. Gray, J. E. 1847. A list of genera of Recent Mollusca, their synonyms and types. Proceedings of the Zoological Societv of London, Part 15:129-219. Guppy, R. J. L. 1867. Notes on West Indian geology, with remarks on the existence of an Atlantis in the Early Ter- tiary period; and descriptions of some new fossils, from the Caribean [sic] Miocene. Geological Magazine 4:496- 501. Guppy, R. J. L. 1876. On the Miocene fossils of Haiti. Quar- terlv Journal of the Geological Societv 32:516-532, pis. 28, 29. ' Ihering, H. von. 1915. Die Opisthobranchien der brasilian- ischen Kiiste. Nachrichtsblatt der Deutschen Malakozoo- logischen Gesellschaft 47(3):133-144. Johnson, C. W. 1934. List of the marine Mollusca of the Atlantic coast from Labrador to Texas. Proceedings of the Boston Society of Natural History 40(1): 1-204. Knight, J. B, 1952. Primitive fossil gastropods and their bear- ing on gastropod classification, Smithsonian Miscellaneous Collections 117(13):l-56, pis. 1, 2. Lange de Morretes, F. 1949. Ensaio de catalogo dos moluscos do Brasil. Arquivos do Museu Paranaense 7(art. 1):5-216. Marcus, E. and E. Marcus. 1964. Verzeichnisdereuthyneuren Meeresschnecken Brasiliens. Beitrage zur Neotropischen Fauna 3:195-206. Maury, C. J. 1917. Santo Domingo type sections and fossils. Part I. Bulletins of American Paleontology 5(29):165-415, 39 pis. Maury, C. J. 1922. Recent Mollusca of the Gulf of Me.xico and Pleistocene and Pliocene species from the Gulf states. Part 2. Scaphopoda, Gastropoda, .Amphineura, Cephalop- oda. Bulletins of American Paleontology 9{38):1-142. Mikkelsen, P, S. 1985. A rapid method for slide mounting of minute radulae, with a bibliography of radula mounting techniques. The Nautilus 99l2-3):62-65. Mikkelsen, P. S. and P. M. Mikkelsen. 1984. Comparison of Acteocina canaliculata (Say, 1826), A. candei (d'Orbigny, 1841) and A. atrata sp. nov. (Gastropoda: Cephalaspidea). The Veliger 27(2): 164-192. Morch, O. A L. 1875. Synopsis molluscorum marinoruni In- diarumoccidentahum. Malakozoologische Blatter fiir 1874 und 1875, 22:142-184. Olsson, A. A. 1922. The Miocene of northern Costa Rica, with notes on its general stratigraphical relations. Part I. Bul- letins of American Paleontology 9(39):309 p., 32 pis. Orbigny, .-K. d'. 1841. Mollusques, vol. 1. /n.Sagra, R Histoire physique, politique, et naturelle de I'lle de Cuba, Paris, 264 p, Orbigny, A, d', 1842. Mollusques, atlas. In: Sagra, R. Histoire physique, politique, et naturelle de I'lle de Cuba. Paris. Peile, A. J. 1926. The Mollusca of Bermuda. Proceedings of the Malacological Society of London 17(2-3):71-98. Perrilliat, M. d. C. 1974. Monografia de los moluscos del Mioceno medio de Santa Rosa, \eracruz, Mexico. Parte III Gasteropodos: P\ramidellidae a Siphonariidae Uni- versidad Nacional Autononia de Mexico, Institute de Geo- logia, Paleontologia Mexicana No. 37:1-46, pis. 1-8, 1 table. Pilsbry, H. A. 1895, Tectibranchiata, Manual of Conchology 15:181-436, pis, 4.3-50, 59-61. Rehder, H. A. 1981. The Audubon Society field guide to North American seashells. Alfred A. Knopf, New York. 894 p. Rice, W. H. and L, S Kornicker, 1965, Mollusks from the deeper waters of the northwestern Campeche Bank, Mex- ico, Publications of the Institute of Marine Science, Uni- versity of Texas 10:108-172, Robinson, E. and J, L. Lamb. 1970. Preliminary paleomag- netic data from the Plio-Pleistocene of Jamaica. Nature 227(.5264):1236-1237. Say, T. 1826. Descriptions of marine shells recently discov- ered on the coast of the United States. Journal of the Academy of Natural Sciences of Philadelphia 5:207-221. Smith, E. A. 1872, Remarks on several species of Bullidae, with descriptions of some hitherto undescribed forms, and of a new species of Planaxis. Annals and Magazine of Natural History 4(9):344-355. Smith, E. A. 1890. Report of the marine molluscan fauna of the island of St. Helena. Proceedings of the Zoological Society of London [April 1, 1890]:247-319, 4 pis. Smith, S. T. 1967. The development of Retusa obtusa (Mon- tagu) (Gastropoda, Opisthobranchia). Canadian Journal of Zoology 45:737-764. Turner, R. D., R. A. Lutz. and D. Jablonski 1985. Modes of molluscan larval development at deep-sea hydrothermal vents. Bulletin of the Biological Societv of Washington No. 6:167-184. Verrill, A. E. and K J. Bush. 1900. .Additions to the marine Mollusca of the Bermudas. Transactions of the Connecticut Academy of Sciences 10:513-544, pis. 63-65. Warmke, G. and R. T. Abbott, 1962. Caribbean seashells. Dover Publications, New York, xx + 348 p., 44 pis Woodring, W. P. 1928. Contributions to the geology and paleontology of the West Indies. Miocene mollusks from Bowden, Jamaica. Part II. Gastropods and discussion of results. Carnegie Institute of Washington, 564 p., 40 pis. THE NAUTILUS 101(2):59-68, 1987 Page 59 A Revision of the Seguenziacea Verrill, 1884 (Gastropoda: Prosobranchia). II. The New Genera Hadroconus, Rotellenzia, and Asthelys James F. Quinn, Jr. Florida Department of Natural Resources Bureau of Marine Research 100 Eigfitfi Ave.. S.E. St. Petersburg, FL 33701, USA ABSTRACT Three new genera of the superfamil\ Seguenziacea are pro- posed, Hadroconus is erected for two western Atlantic and one western Pacific species formerly assigned to Basilissa Watson, 1879. Another species, Basilissa larnpra Watson. 1879. is here made type-species of the monotvpic genus Rotellenzia. One specimen from the syntype series of Carenzia carinata (Jef- freys, 1877) from the North Atlantic Ocean is a juvenile of Basilissa munda Watson, 1879, which is here established as type-species of Asthelys new genus; Basilissa simplex Watson, 1879, is also assigned to this genus. Shells of Hadroconus alius (Watson, 1879). Rotellenzia larnpra (Watson. 1879). and Asthe- lys munda (Watson, 1879), are described and illustrated b\ SEM micrographs and/or light photographs. Comments on util- ity of shell and radular characters for generic definitions are presented. INTRODUCTION The systematics of the Seguenziacea Verrill, 1884, has undergone extensive examination and revision during the last 5 years. Prior to 1983, only six valid genera had been established. An equal number of new genera were erect- ed in 1983 [Marshall. 1983 (5); Quinn, 1983a (1)]. Sub- sequent research on the western Atlantic fauna has re- vealed two additional genera, and examination of the unique specimen of Basilissa larnpra Watson, 1879, makes a third new genus necessary. In a previous paper (Quinn, 1983b), I noted that shell characters were useful in distinguishing between taxa and, in most cases, were the only characters available at the species and genus levels. For example, differences in size of protoconch, number and distribution of primary and secondary sculptural elements (e.g., spiral carinae, cords, threads, collabral riblets), features of the intersec- tion of the sculptural elements (e.g., nodulose or smooth, sharp or rounded nodules, laterally compressed or not), t\pe of columellar tooth, etc., are important in species discriminations. Some characters, especially shell pro- portions, may or may not be adequate for species dis- tinctions and must be evaluated on a case-by-case basis. Ideally, delimitations of genera should entail analyses of shell, radular, and anatomical characters. That ideal is hampered in the Seguenziidae by lack of material available for dissection (see summary in Quinn, 1983b). As a result, all genera have been established principally on the basis of subjective evaluations of shell features, sometimes augmented by a description of the radula. Despite this approach, with the attendant potential for unnecessary generic splitting, authors prior to 1970 \\ ere very conservative in erecting new genera. In three recent papers (Vlarshall, 1983; Quinn, 1983a, b), generic con- cepts of seguenziids have been refined, again based prin- cipally on conchological characters, but no author has presented a discussion of shell characters that, when used in combination, are useful in delimiting genera. I take the opportunity to do so here. Shell shape: With few exceptions, shell shape gives a good first approximation of generic placement. The fol- lowing definitions of shell shape w ill be used in this and subsequent papers; (1) conical — spire height greater than aperture height, sides of spire flat or almost so, sutures not impressed, base flat to weakly convex (Thelyssa Bay- er, 1971; Thelys.sina Marshall, 1983, Basilissa Watson, 1879; Hadroconus new genus; Asthelys new genus); (2) depressed conical — similar to (1) but spire height ap- proximately equal to aperture height and base rather strongly convex (Fluxinella Marshall, 1983; Botellenzia new genus); (3) conico-turbinate — spire height greater than aperture height, spire weakly to strongly gradate, sutures weakly to strongly impressed, base flat to weakly convex (Aiicistrobasis Dall, 1889; Carenzia Quinn, 1983; Segiienziella Marshall, 1983; Basilissopsis Dautzenberg and Fischer, 1897; Seguenziopsis, Marshall, 1983); (4) ovate-conical — spire height greater than aperture height, sides of spire flat or almost so, sutures weakK impressed, base strongly convex [Segiienzia Group III of Quinn, 1983b (this group being described by Marshall, personal Page 60 THE NAUTILUS, Vol. 101, No. 2 communication)]; and (5) ovate-turbinate — similar to (4) but with spire strongly gradate and sutures often strongly impressed (Seguenzia Jeffreys, 1876; Guttula Schepman, 1908). .Midwhorl angulation: Presence or absence of a mid- whorl angulation is consistent within genera, with one exception (see below). "Midwhorl angulation" includes any angulation that is formed along, although not nec- essarily confluent with, the anterior (abapical) edge of the posterior labral sinus and is usually weaker than the peripheral carina. Only one genus {Guttula} lacks any trace of this angulation at any stage of growth. Among those with an angulation, there are three variations: (1) angulation initialK absent, forming on second half of first whorl, then disappearing again later in ontogeny (Thelyssina and Asthelys); (2) angulation initially pres- ent but becoming obsolete or absent after first one to three whorls (Basilissa, most Ancistwbasis, Thelyssa, Fluxinella, Carenzia, and Hadroconus); and (3) angu- lation present on all whorls, often becoming a strong carina (all other genera, plus Ancistwbasis regina Mar- shall, 1983). Axial sculpture: Axial sculpture above the periphery usually comprises fine, sharp threads to strong cords trac- ing, more or less exactly, the outline of the outer lip, but is absent in a few genera. I use the term "sigmoid" to denote the simple reversed S-shape, exemplified by An- cistrobasis, and "collabral" for the more complex con- figuration seen in Seguenzia (for general discussion I include both types in the less precise term "axial"). Again, this sculpture falls into several categories: (1) absent on all whorls (Guttula, Fluxinella, Thelyssina, Seguenziop- sis, and Asthelys); (2) initially present on first one or two whorls as sharp, collabral threads, becoming weak, sig- moid threads on subsequent whorls, or disappearing com- pletely except for plications near the sutures, nodulation of the midwhorl angulation, and/or plications on or cren- ulation of the peripheral carina (Thelyssa, Seguenziella, Carenzia, Rotellenzia, and Hadroconus); (3) initially present on first one or two whorls as sharp, collabral threads and persisting on all subsequent whorls as strong, rounded, sigmoid cords (Basilissa, Ancistrobasis, and Basilissopsis); and (4) present on all whorls as fine, sharp collabral threads (Seguenzia and Seguenzia Group III). The axial sculpture may extend onto the base as trans- verse riblets or threads. The inclination of the axial riblets with respect to the suture line (i.e., an imaginary line connecting the intersections of the riblet ends with the sutures) is useful as an additional character for distin- guishing between genera that have similar shell mor- phologies and sculptural types. At least two cases are known for which this comparison obtains: in Basilissa the axials are prosocline, but in Ancistrobasis they are opisthocline; in Thelyssa the axials are prosocline, but in Hadroconus they arc opisthocline. Labral sinuses: The number of labral sinuses in the shell lip is one of the more important characters, if not the most important, in seguenziid systematics. Absence of a sinus in the shell lip does not necessarily reflect a corresponding lack of a sinus in the mantle edge, nor do the shapes of axial riblets necessarily reflect the exact shape of the posterior sinus. Most seguenziid genera have either two or three sinuses (see Marshall, 1983; Quinn, 1983b). Guttula alone has none, and Thelyssina seem- ingly has only one. Seguenzia, previously defined in part by presence of three sinuses, actualK has a fourth (a wide, open. Dared extension of the basal lip, rarely pre- served in either dead- or live-collected material) located in the extreme inner (adaxial) part of the basal lip; this sinus corresponds to a papillate sinus in the mantle (Quinn, 1983b). The shape of the posterior sinus has been described as J-, reversed L-, U-, or V-shaped (Quinn, 1983b). How- ever, this actually was a description of the shape of the axial riblets in the selenizone behind the sinus itself. (1) The J- and reversed L-shapes are merely variations on a common theme in which the lower arm of the sinus is essentially parallel to the suture line, and the apex (closed end) is broadly and evenly rounded (Seguenzia, Se- guenzia Group III, Hadroconus, and possibK Thclys.sa). (2) The V-shape is that in which the upper and lower arms of the sinus are divergent and the apex is narrowly rounded (Carenzia, Seguenziella, Fluxinella, Rotellen- zia). (3) The U-shape should actualK, and loosely, be termed "broadly U-shaped", because the apex is very broadly and evenly rounded, but the upper and lower arms of the sinus are divergent, not parallel (Ancistro- basis. Basilissopsis, Asthelys. and probably Basilissa). (4) The sinus edge in Seguenziopsis apparently sweeps for- ward in a sigmoid, opisthocline line with the posterior- most point at the suture. As indicated above, the true shape and depth of the posterior sinus is not necessariK reflected in the shape of the axial sculpture. For example, in Hadroconus the sigmoid axial threads suggest a very shallow, broadly U-shaped sinus similar to that of Ancistrobasis, but the sinus of the former is actualK considerabK deeper than that of Ancistrobasis, and the lower arm is parallel, or nearly so, to the suture line. However, in Ancistrobasis, Basilissopsis, and probably Basilissa, the sigmoid axials accurately trace the sinus (Marshall, 1983; Quinn, 1983b, unpublished observations). This does not, however, ob- viate the systematic value of the shapes of axials for discriminating between closely related taxa (Quinn, in preparation). Depth of the posterior sinus is defined here b> arbitrary sinus depth: shell diameter ratios (X) — very shallow = X < 0.10; shallow = 0.10 < X < 0.20; moderate = 0.20 < X < 0.30; deep = X > 0.30. Umbilicus: The presence, absence, and relative width of the umbilicus may or may not be of systematic sig- nificance at the generic level; characteristics of the um- bilicus usualK are useful onK at the species level. How- ever, presence of an umbilical septum is a rare feature in the Seguenziidae, as it also is in the Trochacea. An umbilical septum is known only in Basilissa superba J. F. Qiiinn, Jr., 1987 Page 61 Watson, 1879, and Tliclyssa callisto Bayer, 1971, and is here considered autapomorphic in Imtli genera. Radula: The snperfamil\ has been characterized b\' the presence of a single pair of lateral teeth and more than two pair of marginal teeth in each radular tooth-row (Qiiinn, 1983b). Including the three new genera defined here, radulae have been illustrated for nine of the fifteen described genera (including Scg(/('?i;ia Group III). These illustrations seem to indicate three distinct types of lateral teeth: (1) Type I is broadly triangular, with the dentic- ulate cusp not narrowed {Ancistrohasis, Fluxinella, Had- ruconus. and Guttula in part); (2) Type II has a broad, triangular base, but with a long, narrow cusp arising from the proximal corner (Seguenzia, Seguenziella and Ro- tellenzia); and (3) Type III is a simple, triangular tooth base lacking a cusp (Guttula in part, Carcnzia, and Se- guenzia Group III). At present, structure oi the rhach- idian and number of marginals cannot be satisfactorily categorized. In summary, characters of genus-level importance in- clude shell shape, expression and persistence of a mid- whorl angulation, expression and shape of axial sculpture, shape of the posterior labral sinus, presence or absence of an umbilical septum, and shape of the lateral tooth of the radula. The number of labral sinuses is probably significant at higher taxonomic levels. Features not nec- essarily useful for discrimination of genera include pres- ence or absence of an umbilicus or columellar tooth and, in most cases, spiral sculpture. However, it must be stressed that all characters must be used in combination, and anatomical characters should also be included when available. I believe that, although anatomical details are lacking for most described genera, and radulae are un- known for several, basing genera principally on shell characters still has validit\ in the Seguenziidae, and I am confident that anatomical characters, when known, will confirm the validity of most, if not all, seguenziid genera now defined on conchological characters. Institutional abbreviations used in this paper are: BM(i\H), British Museum (Natural History); MCZ, Mu- seum of Comparative Zoology, Harvard University; MNHN, Museum National d'Histoire Naturelle, Paris; TAMU, Systematic Collection of Marine Organisms, Te.xas A&M University; UMML, Rosenstiel School of Ma- rine and Atmospheric Science, University of Miami; USNM, U.S. National Museum of Natural History. Hadroconus new genus Basilissa Watson, 1879:593 (partim); 1886:96 (par(im).— Mar- tens, 1881:56 (par(im).— Dall, 1881:48; 1885:34 (partim); 1889a:32, 384 [partim). 1889b:164-165 (partim); 1890: 354; 1927:109 (par(im).— Fischer, 1885:827 (partim).— Pilsbrv, 1889:15, 419 (parhm). —Schepman, 1908:61 (par- tim).—Maury, 1922:157 (par/im ).—Thiele, 1929:48 (par- tim).—]o\ir\son, 1934:73 (par/im). —Wenz, 1938:276 (par- (im).— Cotton, 1959:189 (par(im).— Keen and Cox, 1960: 1250 (par/im).— Clarke, 1962:12 (parfim).— Bayer, 1971: 123.— Abbott, 1974:39 (partim).— Quinn. 1979:49 (par- tim); 1981:74 (partim). 1983b:729 (par/im).— Goryachev, 1979:70 (partim)— Boss, 1982:974 (partim). Seguenzia: Daii, 1881:48 (partim). Type-species: Basilissa alt a Watson, 1879; here desig- nated. Gender: Masculine. Diagnosis: Shell small, conical, peripheralK carinate, umbilicate, nacreous under thin outer porcelaneous lay- er, white, polished; spire with flat to slightly concave sides, sculptured by widely spaced, sigmoid axial riblets, and fine spiral threads; periperal carina strong, overlaid with several spiral threads, crenulated by terminations of axial riblets; base slightly convex, with strong, flattened spiral cords and/or narrow threads; umbilicus wide, deep, funnel-shaped, bounded by strong, tuberculate cord; ap- erture subrectangular; outer lip thin, with shallow pos- terior sinus occupying adapical half of whorl, claw-like near periphery; basal lip thin, w ith wide, shallow sinus in outer part; columella straight, slightK' oblique, some- what inflated medially, terminating in a rounded boss. Remarks: Cossmann (1888) designated Basilissa super- ba Watson, 1879, as type-species of Basilissa Watson, 1879, although B. alta Watson, 1879, has been the species most frequently associated with that genus. Because that type-designation may not be changed, Hadroconus is erected for B. alia, B. sibogae Schepman, 1908, B. tvat- soni Dall, 1927, and an undescribed western Atlantic species. Together, these four species form a morpholog- ically cohesive species-group that may be distinguished from all other seguenziacean genera. Shells of these four species are small ( < 10 mm), have spiral sculpture much weaker than axial riblets, or predominantK absent, the axial riblets are strongly sigmoid and opisthocline, and the umbilicus lacks a septum. Shells of B. superba are large ( > 20 mm), have spiral sculpture subequal to axial riblets, axial riblets almost a simple prosocv rt arc except for a weak opisthocyrt sinuation near the adapical suture, axials weakly prosocline, and umbilicus partially covered by a septum. In addition, shells of Hadroconus species usually have height : width (h:w) ratios less than 1.0, those of B. superba greater than 1.0; however, two specimens of H. attus (UMML 30.8155) have h:w ratios of 1.03 and 1.07, and Okutani (1982) recorded two juvenile speci- mens of B. superba with h:w ratios of 0.96 and 0.98 (he did not indicate whether apical parts of these specimens are intact). Shells of Hadroconus are most similar to those of The- lijssa Ba\er, 1971, but differ in that the axial riblets are rather strongly sigmoid and opisthocline, and the um- bilical walls lack callus and an umbilical septum. Had- roconus and Thchjssa are apparentK' sister taxa sepa- rated principalK by the autapomorphic umbilical septum of Thelyssa. Although I have not had an opportunity to examine a properly preserved specimen of any species of Hadro- conus, dried specimens of both H. alius and H. watsoni were available for study and afforded the following ob- Page 62 THE NAUTILUS, Vol. 101, No. 2 Figures 1 -5. Hadroconus alius (Watson, 1879). 1,2. Apertural and basal views of lectotype of Basilissa aha, BM(NH) 1887.2.9.351. height 6.3 mm, maximum diameter 5.9 mm. 3. Apertural view of specimen from Gerda station G-965, UMML 30.7759 (SEM micrograph, x 9), 4. Protoconch of another specimen from G-965 (SEM, x 140). 5. Same, apical view (SEM, x 9). servations of external anatomy. A well-developed epi- podium bears four (or five) to six epipodial tentacles. The mantle edge has two broad sinuses, corresponding to the basal and posterior labral sinuses of the shell; mid-dor- sally is a prominent, seemingly papillate tentacle, to the left of which is a narrow, C-shaped sinus which corre- sponds to the peripheral angulation of the shell. The esophagus, seen by transparency after the animals were soaked in trisodium phosphate, e.xtends posteriori) from the buccal area, sharply turns ventrally at the level of the last intestinal turn, and then runs posteriorly along the ventrolateral surface of the right intestinal tract. The intestine is similar to that of Segitcnzia sp. cf. S. eritinia V'errill, 1884 (Quinn, 1983b), but coils in the opposite direction; the shape of the fecal string is also similar to that of Seguenzia: oval with a shallow medial groove on one side. The cephalic tentacles are long, papillate, ap- prcssed basalK, and a long, slender penis arises just to the right of the right cephalic tentacle. On either side of the snout is a prominent, paddle-shaped oral lappet. Etymology: From the Greek adros, stout, strong, and konos, a cone. Hadroconus alius (Watson, 1879) (figures 1-5) Basilissa alia Watson, 1879:597; 1886:100, pi. 7, fig. 8.— Mar- tens, 1881:56.— Dall, 1881:48; 1885:34; 1889a:32, 384; 1889b: 164-165; 1890:.354,— Pilshrv, 1889:419, pi. 36, fig. 5.— Maurv, 1922:157.— Johnson, 1934:73.— Cotton, 1959: 189 —Clarke, 1962:12— Bayer. 1971:123, figs. 6D-G, l.\- D.— Abbott, 1974:37, fig. 239— Quinn, 1983b;729, figs. 13, 28, 40. Seguenzia dclicatula Dall, 1881:48; 1885:265. Bfl.si/i.vxfl alta var. oxytoma Watson, 1886:100, pi, 7, fig. 8a. — I'iLshry, 1889:421, pi. 36, fig. 4. Basilissa alta var. delicatula: Dall, 1889a:384, pi. 22, figs. 2, 2a; 1889b:164-165. — Pil.shr\. 1889:421, pi. 48, figs. 3, 4.— Maury, 1922:158. Basilissa delicatula delicatula: Johnson, 1934:73. Basilissa (Basilissa) alia: Quinn, 1979:50, figs. 83, 84. J. F. Quiiin, Jr., 1987 Page 63 Material examined: 1 specimen, UMML 30.8156; Co- lumbus Iselin sta. CI-356, 24°28.3'N, 77°29.5'W, 1,597 m; 40 foot otter trawl; August 20, 1975. — 1 specimen, UMML 30.8146; Gerda sta. G-478. 24°15'N, 82°11'W, 543-348 m; 10 foot otter trawl; Januar\' 26, 1965.— 3 specimens, UMML 30.8152; Ccrda sta. G-967, 24°15'N, 82°26"W, 499-503 m; 10 foot otter trawl; February 2, 1968.— 1 specimen, UMML 30.8018; Gerda sta. G-1099, 24°12.5'N, 82°50'W, 622 m; 10 foot otter trawl; April 28, 1969—1 specimen, UMML 30.8144; Gerda sta. G-356; 24°11'N, 81°37'W, 672 m; 10 foot otter trawl; September 15, 1964.-1 specimen, UMML 30.8151; Gerda sta. G-966, 24°10'N. 82°22'W, 553-558 m; 10 foot otter trawl; Feb- ruary 2, 1968.— 1 specimen, UMML 30.8147; Gerda sta. G-815, 24°08'N, 79°48'W, 618 m; 10 foot otter trawl; June 27, 1967.— 1 specimen, USNM 94941; Blake sta. 43, 24°08'N, 82°51"W, 620 m — 1 specimen, UMML 30.8145; Gerda sta. G-370, 23°54'N, 81°19'W, 1,281 m; 16 foot otter trawl; September 16, 1964. — 1 specimen, UMML 30.7764; 2 specimens, UMML 30.8150; Gerda sta. G-964, 23°46'N, 81°51'W, 1,390-1,414 m; 10 foot otter trawl; February 1, 1968. — 5 specimens, UMML 30.7759; Gerda sta. 'G-965, 23°45'N, 81°51'W, 1,394- 1,399 m; 10 foot otter trawl; February 1, 1968.-1 spec- imen, UMML 30.8022; Gerda sta.'G-1112, 23°44'N, 81°14'W, 2,276-2,360 m; 10 foot otter trawl; April 30, 1969.— 1 specimen, MCZ 7596; Blake sta. 41, 23°42'N, 83°13'W, 1,573 m.— 1 specimen, UMML 30.7692; Gerda sta. G-963, 23°41'N, 82°16'W, 1,441-1,454 m; 10 foot otter trawl; February 1, 1968. — 7 specimens, UMML 30.8149; Gerda sta. G-960, 23°30'N, 82°35'W, 1,692- 1,697 m; 10 foot otter trawl; January 31, 1968. — 5 spec- imens. UMML 30.8148; Gerda sta. G-959, 23°25'N, 82°26'W, 1,830 m; 10 foot otter trawl; January 31, 1968.— 6 specimens, MCZ 135024; Atlantis sta. 2993, 23°24'N, 80°44'W, 1,061 m; 14 foot Blake trawl; March 15, 1938.— 1 specimen, MCZ 135022; Atlantis sta. 2987E, 23°19'N, 79°59'W, 576 m; 14 foot Blake trawl; March 13, 1938.— 1 specimen, MCZ 135023; Atlantis sta. 2988, 23°15'N, 79°57'W, 695 m; 14 foot Blake trawl; March 14, 1938 — 1 specimen (lost), MCZ 7598 (? holotype of Seguenzia delicatula); 1 specimen, USNM 94943; Blake sta. 2, 23°14'N, 82°25"W. 1.472 m — 1 specimen, MCZ 135021; Atlantis sta. 2989, 23°10'N, 80°04"W, 658 m; 14 foot Blake trawl; March 14, 1938—11 specimens, MNHN; Alaminos sta. 66-A9-15, 28°13.5'N, 87°04'W, 1,200-800 m; 10 ft midwater trawl; 1967. — Fragments, USNM 93805; A/foifross sta. 2384, 28°45'00"N. 88°15'30"W. 1,719 m; large beam trawl; March 3, 1885. — 3 specimens, MNHN; Alaminos sta. 69-A11-7, 27°01.3'N, 94°43.5'W, 1,399 m; 3 m benthic skimmer; 1969. — 3 specimens, TAMU 4-1950; Alaminos sta. 69-A11-74, 21°29'N, 96°41.5'W, 1,189-1.280 m; 3 m benthic skimmer; August 22, 1969—1 specimen, UMML 30.8153; John Elliott Pillshunj sta. P-585, 21°02'N. 86°29'W, 567-570 m; 10 foot otter trawl; May 23, 1967. — 1 specimen. MCZ 135261; Atlantis sta. 3370.' 20°47'N. 75°11'W, 829 m; 14 foot Blake trawl; April 20, 1939—1 specimen, USNM 429445; 12 specimens, USNM 429465; 3 specimens, USNM un- catalogued; Johnson-Smithsonian Deep-Sea Expedition sta. 67, 18°30'12"N. 65°45'48"W, 329-512 m; 4 foot dredge; February 23, 1933. — 1 specimen, BM(NH) 1887.2.9.351 (lectotype); 1 specimen. BM(NH) 1887.2.9.352 (paralectotype); Challenger sta. 24, 18°30'30"N. 65°05'30"W, 713 m; March 25, 1873.-1 specimen, USNM 214142; Albatross sta. 2750, 18°30'N. 63°3rW. 913 m; 2 foot ship's dredge; Noyember 27. 1887.-2 specimens, UMML 30.8327; John Elliott Pills- bury sta. P-988. 18°29.3'N, 63°24'W. 686-723 m; 5 foot Blake trawl; July 23, 1969.-2 specimens, UMML 30.8328; John Elliott Pillsbury sin. P-1255, 17°18'N, 78°32'W. 23- 622 m; 10 foot otter trawl; July 14, 1970. — 4 specimens, UMML 30.8155; John Elliott Pillsbury sta. P-1261, 17°13'N. 77°50'W, 595-824 m; 10 foot otter trawl; July 15, 1970.-14 specimens, USNM 95399; 9 specimens, USNM 614087; Albatross sta. 2751, 16°54'N, 63°12'W, 1,257 m; large beam trawl; November 28, 1887. — 1 spec- imen, MCZ 7597; Blake sta. 163. 16°03'10"N. 6r52'20"W, 1,407 m; Januarx 20, 1879—1 specimen, UMML 30.8154; John Elliott Pillsbury sta. P-861, 12°42'N, 61°05.5'W, 18-744 m; 10 foot otter trawl; July 4, 1969. — 2 specimens, USNM 94942; Blake sta. 264. 12°03'15"N. 61°48'30"W. 767 m; March 1, 1879—1 specimen, USNM 96876; Al- batross sta. 2754, ir40'N, 58°33'W, 1,609 m; large beam trawl; December 18, 1887.— Fragments, BM(NH) 1887.2.9.353; Challenger sta. 120, 8°37'S, 34°28'W, 1,235 m; September 9, 1873. — 11 specimens, USNM 150756; Albatross sta. 2760, 12°07'S, 37°17'W, 1,864 m; large beam trawl; December 18, 1887. Description: Shell small (height of largest specimen 7.2 mm, width 8.2 mm), conical, peripheralK carinate, pol- ished, white, iridescent under thin outer porcelaneous layer. Protoconch 375-450 ^m (usually about 425 nm) in ma.ximum diameter, prominent, glassy. Teleoconch whorls 7.5-8.0; spire whorls flat, with widely spaced (2- 4 per mm) sigmoid a.xial riblets and fine spiral threads; sculpture usually strongest near suture and peripher)-, obsolete medially on whorls 3-6, becoming distinct again on whorls 7-8; suture distinct but not impressed. Pe- riphery marked by strong carina, overlain by about 4 spiral threads, rendered strongly denticulate by the axial riblets, visible on all whorls. Base almost flat, often smooth medially, otherwise with strong spiral cords and obscure transverse threads in striae between spiral cords; sculp- ture stronger near umbilicus. Umbilicus wide, approxi- mately 24% maximum shell diameter, bounded periph- erally by strong, tuberculate spiral cord, .\perture subrectangualr, lips thin; outer lip bisinuate. with pe- ripheral spur, and with wide, moderately deep. U-shaped posterior sinus, abapertural edge of which slightly flared; basal lip with wide, shallow, sinus, with weakly flared edges, apex in outer third of lip; columella straight, slight- ly oblique, distinctK inflated medially, terminating in rounded boss. Animal occupies approximately 2 whorls, with esti- mated length of 8-10 mm. Epipodium prominent, flap- like, bearing 4 (probably 5) epipodial tentacles, ante- Page 64 THE NAUTILUS, Vol. 101, No. 2 riormost and posteriormost rather long, slender, middle 2 (or 3) much shorter. Esophagus running posteriorly from buccal area, making sharp ventral turn at level of last intestinal loop, then running posteriorly along ventral margin of right intestinal tract. Intestine very long, prob- ably 15-20 mm total length when complete, running forward along left side of animal, forming series of tight convolutions and loops in anterior 2-3 mm, abruptly crossing to right side approximately 2 mm posterior to mantle edge, making short, tight dorsal loop before run- ning posteriorly in series of strong sinuations; at some point posterior to preserved sections, intestine makes sharp U-turn, running anteriorly along left side of animal, the 2 sections closely appressed posteriorly, then separated by intervening structures anteriorly; about 3 mm pos- terior to mantle edge it makes 2 tight right-left loops, then runs straight along left side for about 2 mm, turning sharpK right for about 0.5 mm, finally running anteriorly for final 1.5 mm; anus lying just posterior to edge of mantle on right side of animal. A 3 mm long fragment from near posterior reach of intestine contained some loops of intestine and/or esophagus ventrally and an ovate, 1.75 mm long organ that occupied the same rel- ative position as the kidney of Segnenzia cf. sp. S. eritima (see Quinn, 1983b: fig. 34), but was solid and evenly rounded, rather than delicate and somewhat lobulate as in the Seguenzia species. No other features were ob- served because of poor preservation. Radula lost during preparation for SEM. "The operculum is circular, very thin, concave, of about four whorls. The radula , . . has a rhachidian with a triangular cusp finely denticulated on the sides, a wide lateral with an inwardly directly [sic, directed] triangular cusp denticulated on both sides, and several (6 or 7) marginals, flat and rather narrow, denticulated along most of the outer edge but on the inner edge onlv near the tip" (Bayer, 1971:124). Measurements: Lectotype [BM(NH) 1887.2.9.351; here designated]: 6.3 mm high, 5.9+ mm wide. Largest spec- imen: 7.2 mm high, 8.2 mm wide. Type-locality: NW of St. Thomas, Virgin Islands, Chal- lenger sta. 24, 18°30'30"N, 65°05'30"W, 713 m (here designated). Remarks: All four species of Hadroconns are very sim- ilar morphologically. Hadroconns sibogae (Schepman, 1908), from Makassar Strait, off Celebes Island, Indo- nesia, differs from the three western Atlantic species in that it totally lacks spiral sculpture on the upper whorl surface, except for "one or two spiral elevated striae . . . on part of the upper whorls (Schepman, 1908:62-63). The three western Atlantic species are more difficult to distinguish from each other, especialK because of the iiitraspecific variation of shells of H. altus. Discussions and analyses of characters distinguishing //. altiis from //. watsoni (Dall, 1927) and the undescribed species will be presented in a future paper revising the western At- lantic Hadroconns. Intraspecific variation in shells ol H. altns is extensive. The height: width (h:vv) ratio varies from 0.68 to 1.07 (x = 0.85 ± 0.10; N = 22); the lower the ratio, the more distinctly concave the spire outline becomes. In a manner similar to that of the spiral sculpture above the periphery, the basal spiral cords tend to become obsolete on the medial part of the base. This smooth area varies from 15% to 47% (x = 28.5%) of the umbilicus-periphery distance. In a few specimens [BM(NH) 1887.2.9.351-352, and UMML 30.8018, 30.8151, and 30.8155], the basal spiral cords are all strong and separated by strong grooves. These specimens also had the highest h:w ratios (0.97- 1.07) and some of the smallest protoconchs (375-400 ^m), but these values were not significantly different from those of the lower spired forms (Student s t; P < 0.05). Hadroconns altns is known from the Bahamas, Straits of Florida, Gulf of Mexico, Yucatan Channel, the entire Antillean Arc, and oft Brazil. Bathymetric occurrence is about 500-700 m in the northern Straits of Florida, and generally deeper than 1,000 m elsewhere, with the deep- est record (2,276-2,360 m) in the southern Straits of Florida. Depths of the three lots with live-collected spec- imens were 805-722 m (UMML 30.8328, P-1255). 1 ,200- 800 m (MNHN, Alaniinos sta. 66-A9-15), and 1,390- 1,414 m (UMML 30.8150, G-964). Hadroconns altns thus seems to inhabit depths considerabK greater than those in which either of the other western Atlantic species live (H. watsoni: approximateU' 430-805 m: Hadroconns n. sp.: 329-512 m; personal observations). Rotellenzia new genus Basilissa: Watson, 1879:.593 {partim); 1886:96 (partim).— Schepman, 1908:61 (par/im).— Cotton, 1959:189 {par- tim). Seguenzia Group II: Quinn, 1983b:728 {partim). Type-species: Basilissa lampra Watson, 1879; here des- ignated. Gende Feminine. Diagnosis: Shell of moderate size, depressed conical, weakly carinate peripherally, fragile, brilliantly irides- cent under very thin outer porcelaneous layer, color brassy; spire almost flat-sided, sutures weakK impressed; whorls with 2 weak carinae at periphery, visible onl\ on last whorl, with numerous spiral threads above peripheral cords, strongest on first 3 whorls, obscure subsequently; axial sculpture of low riblets on first 1.5 w horls, thereafter almost absent; base weakly convex, with numerous spiral threads, umbilicate; umbilicus wide, defined by strong, smooth spiral cord; aperture rhomboidal; lips thin with broad, \'-shaped posterior sinus, and broad, ver\ shallow. U-shaped basal sinus; anterolateral sinus, it present, prob- ably narrow, shallow and U-shaped; columella thin, very weakly sigmoid, edentate. Remarks: The shell of the t\ pe-species of this genus is most similar to those of species of Segnenziella Marshall, 1983. Rotellenzia lampra. however, lacks the strong mid- whorl and peripheral carinae which characterize Se- J. F. Quinn, Jr., 1987 Page 65 / ^ A;* N^lfea^ Figures 6-8. Rolellenzia lainpra (Watson, 1879). Apical, apertiiral, and basal views of holot\pe of Basilissa lampra. BM(NH) 1887.2.9.348, height 7.5 mm. maximum diameter 12.2 mm. Figures 9, 10. Asthehjs miinda (Watson, 1879), Apertiiral and basal views of holotvpe of Basilissa munda, BM(NH) 1887.2.9.350, height 3.0 mm, maximum diameter 3.3 mm. guenziella. Moreover, if Schepman's (1908: text fig. 1) illustration of the radula of R. lampra is accurate, the odd structure of the cusps of the rhachidian and laterals further separates the two genera. However, the two gen- era undoubtedK are closely related, and, on the evidence of the radula, both are more closely allied to Seguenzia Jeffreys, 1876, than to other genera with similar shell shapes, such as Carenzia Quinn, 1983. If the similarities of shells hold between Rotcllenzia and Seguenziella, a narrow, U-shaped anterolateral labral sinus probably ex- ists. However, the chipped lip of the holotype of R. lampra prevents direct observation of this feature, and the growth lines give no additional indication, a situation also found in Scgiienziella. Etymology: From the Latin diminuati\e of rota, a wheel, and Seguenzia, a genus of Seguenziidae. Rolellenzia lampra (Watson, 1879) (figures 6-8) Basilissa lampra Watson, 1879:593; 1886:97, pi. 7, fig. 5. — Schepman, 1908:61, text fig. 1.— Cotton, 1959:189. Seguenzia lampra: Quinn, I983b:728, fig. 45. Material examined: 1 specimen, BM(NH) 1887.2.9.348 (holotvpe); Challenger sta. 246, 36°10'N, 178°00'E, 3,749 m; July 2, 1875. Description: Shell of moderate size (height 7.5 mm, width 12.2 mm), depressed conical, weakly carinate pe- ripherally, umbilicate, thin, iridescent under very thin porcelaneous layer, brass-colored. Protoconch large, about 500 ^m in maximum diameter, about 1 whorl. Teleo- conch whorls 5.25, spire whorls flat to weakly convex; first 3 whorls with fine, sharp spiral threads, one at mid- whorl strongest, subsecjuent whorls with spirals subequal in strength, all becoming weaker over last 2 whorls; threads number 19 near aperture; last whorl with 2 strong, smooth spiral cords, anterior one peripheral, posterior one close above and along which suture runs, interspace narrow, weakly concave; axial sculpture of low, sharp collabral riblets on first 1.5 whorls, thereafter rapidly disappearing, except near suture where they remain ev- ident as short, comma-like folds. Base weakly convex, umbilicate, with 15 spiral cords (increasing rapidK near aperture to 25), outer 3 rather strong, separated by con- cave interspaces bearing 3-4 fine spiral threads near ap- erture, middle 75% of base with 9 broad, flat spiral cords separated by shallow striae, inner 3 cords strong, sharp, separated b\ concave interspaces with fine, sharp trans- verse riblets. Umbilicus wide, about 30% maximum shell diameter, funnel-shaped, walls weakly concave, smooth except for growth lines. Aperture trapezoidal; outer lip thin, posterior sinus shallow, broadly \'-shaped, apex in posterior 25% of whorl; basal lip thin, basal sinus a wide, very shallow sinuation of lip, apex located in abaxial quarter of base; columella thin, weakly concave in adap- ical half, weakK con\ex in abapical half Operculum unknown. Radula with lanceolate rhachidian, cusp not reflected, finely denticulate along cusp base, unarmed Page 66 THE NAUTILUS, Vol. 101, No. 2 Figures 11-14. SEM micrographs of Asf/if/ys munda (Watson, 1879) from Porcupine st&iion 22, USNM 859916. II. Apertural view, X 45.5. 12. Oblique apical view, x 42. 13. Protoconch, x 126. 14. Oblique basal view, x 45.5. distally; lateral with wide, triangular base, long, unre- flected cusp on proximal side, finely denticulate along distal edge well back from tip; inner marginal sickle- shaped, edentate. Holotype: height 7.5 mm, width 12.2 Measurements: mm. Type-locality: NW of Midway Island, Hawaiian Is- lands, Challenger sta. 246, 36°10'N, 178°00'E, 3,749 m. Remarks: See under generic remarks. Asthelys new genus Seguenzia: Jeffreys, 1877:320 {partini). Rasilissa Watson. 1879:59.3 (partim): 1886:96 (parhm).— Quinn, 1983b:729 (partim). Type-species: Basilissa tiiunda Watson, 1879; here des- ignated. Gender: Feminine. Diagnosis: Shell small, conical, |5eripherall\ bicariiiate, umbilicate, nacreous under thin outer porcelaneous la\- 61 white; protoconch large; first 0.5 whorl lacking spiral sculpture, subsequent whorls with strong cord abo\e pe- riphery and strong peripheral cord, together forming weakly bicarinate periphery, weak to strong spiral cords on base, and strong, smooth or pustulate circumumbilical cord; a.xial sculpture of obscure, sigmoid folds and growth lines; surface microsculpture of microscopic, shallow punctae; base weakly conve.x; umbilicus narrow, funnel- like; aperture subquadrate; labral sinuses 2, wide, shal- low; columella straight or weakly concave. Radula un- known. Remarks: Aslhclys most closeK' resembles Thelyssina Marshall, 1983. Shells of both genera are conical with almost flush sutures, lack a midw horl carina, spiral cord, or angulation on the first teleoconch whorl immediately follow ing the termination of the protoconch, lack strong coUabral and spiral microsculpture above the whorl pe- riphery, and have a narrow, funnel-like umbilicus. The type-species of Asthelys differs from that of Thelyssina by lacking a trochoid tip and terminal rim on the pro- toconch, having minute punctae instead of vermiculate microsculpture on the first two spire whorls (although T. sterrha Marshall, 1983, also has punctations, fide Mar- shall, personal communication), ha\ ing a bicarinate rath- er than unicarinate periplier\ , ha\ ing a distinct posterior J. F. Quinn, Jr., 1987 Page 67 shell sinus, persistence of the initial spiral cord on all teleoconch whorls, and lacking a strong parietal callus. At least two other species may also be assigned to Asthe- lys: Basilissa simplex Watson, 1879, and an undescribed Antarctic species (Marshall, personal communication). Etymology: .\nagram of Thelyssa. a genus of Seguen- ziidae Asthelys miinda (Watson, 1879) (figures 9-14) Seguenzia carinata Jeffreys, 1877:320 (partim). Basilissa mimda Watson, 1879:596; 1886:99, pi. 7, fig, 7,— Quinn, 1983b:729, [Son Basilissa munda Barsanova, 1966: 150 (misidentiflcation).] Material examined: 1 specimen, USNM 859916 [(para- lectotvpe of Carcnzia carinata (Jeffre\'s, 1877)]; Porcu- pine sta. 22, 56°08'N, 13°34'W, 2,311 m; July, 1870.— 1 specimen, BM(\H) 1887.2.9.350 (holotvpe); 'c/ia//r»gfr sta. 85, 28°42'N, 18°06'W, 2,058 m; August 29, 1873. Description: Shell \er\ small (height of holotype 3,0 mm, width 3.3 mm), conical, weakly bicarinate periph- erally, narrowly umbilicate, thin, iridescent under thin outer porcelaneous layer, white. Protoconch with irreg- ular microsculpture, about 350-375 /um maximum diameter, of about 1 whorl, lacking terminal rim. Te- leoconch whorls 4.75; spiral sculpture absent on first half- whorl; fine spiral thread appears on second half-whorl, located at abapical fifth of whorl, gradually strength- ening to become subequal to peripheral cord; peripheral cord visible only on last whorl, forming bicarinate pe- riphery with upper spiral cord; axial sculpture present on all whorls, consisting of e.xtremely obscure sigmoid folds, most apparent as undulations of spiral cords; sur- face microsculpture of microscopic, extremeK- shallov\' punctae generally arranged in spiral pattern. Base weak- ly convex, with 11 spiral cords, innermost strongest, with 8 pustules, and sigmoid transverse rugae and minute punctae. Umbilicus narrow, about 14^ of maximum shell diameter, funnel-shaped, walls smooth except for axial growth lines. Aperture subquadrate; outer lip thin, with very wide, shallow, U-shaped posterior sinus, apex lo- cated above midwhorl; basal lip thin, with ver\' wide and shallow basal sinus, apex at abaxial third of base; columella almost straight, very weakly concave above, very weakly convex below, slightly thickened, edentate. Type-locality: W of Palma, Canarv Islands, Challenger sta. 85, 28°42'N, 18°06'W, 2,058 m'. Remarks: Asthelys munda is most similar to A. simplex (Watson, 1879), but A. munda is smaller, relatively broader, lacks a subsutural spiral cord, and has weaker basal spiral cords, pustulate circumumbilical cord, and less oblique aperture. The specimen from the Porcupine Expedition is a juvenile (figures 9-12) from the syntype lot of Carenzia carinata (Jeffreys, 1877). The localit)' of this specimen (NW of Ireland) extends the known range of the species northward more than 2,600 km, indicating a distribution throughout the northeastern Atlantic in depths of about 2,000 m, ACKNOWLEDGEMENTS Special thanks are due to Bruce A, Marshall (National Museum of New Zealand) for providing me with results of his work on New Zealand seguenziids, particularly on Asthelys, and for reading a previous version of this paper. His willingness to share such information has made it possible to avoid certain errors of commission, as well as omission. I thank the two anonymous reviewers for their constructive comments. I thank the following for allow- ing access to specimens in the collections under their charge: Richard S, Houbrick and the late Joseph Rose- water, USNM; Gilbert L, Voss, UMML; Philippe Bou- chet, MNHN; and John Taylor and Kathie Way, BM(NH ). Some of the specimens examined for this paper were collected during the National Geographic-Universitv- of Miami Deep-Sea Expeditions supported by a grant from the National Geographic Society, Washington, D.C, Ar- thur E. Bogan (ANSP), David K. Camp, and Jennifer Wheaton (Florida Department of Natural Resources, Bu- reau of Marine Research) commented on a draft of this paper. The SEM micrographs of Hadroconus alius were made by Lana Tester (formerly Florida Department of Natural Resources, Bureau of Marine Research); those of Asthelys munda were made b>' the author under a Morris K. Jacobson Scholarship award from the Astronaut Trail Shell Club, Melbourne, Florida. Sally Kaicher pro- vided photographs of the types. A portion of this paper was a part of a dissertation submitted to the Universitv of Miami in partial fulfillment of the requirements for the degree of Doctor of Philosophy, and constitutes a scientific contribution from the Rosenstiel School of Ma- rine and Atmospheric Science, Universit>' of Miami, Cor- al Gables, Florida. LITERATURE CITED .Abbott, R, T, 1974, American seashells, 2nd ed. Van Nostrand Reinhold, New York, NY, p. 663, Barsanova, N, G, 1966, K nachozhdeniyu glubokovodnikh predstavitelei semeistva Seguenziidae (Gastropoda, Pro- sobranchia) v Tikhom Okeane, [On the finding of deep- sea representatives of the family Seguenziidae (Gastrop- oda, Prosobranchia) in the Pacific Ocean,] Trudy Instituta Okeanologii 81:144-152. Baver, F. M, 1971, New and unusual mollusks collected by R/V JOHN ELLIOTT PILLSBURY and R/V GERDA in the tropical western Atlantic. Bulletin of Marine Science 21(l):lll-236, Boss, K. J, 1982. Seguenziidae, /n; Parker, S. P. (ed.). Synopsis and classification of living organisms. Vol, 1, McGraw- Hill, New York, NY, p. 973-974. Clarke, A. H. 1962. Annotated list and bibliography of the abyssal marine molluscs of the world. National Museum of Canada, Bulletin 181:vi + 114 p, Cossmann, M. 1888, Catalogue illustre des coquilles fossiles de I'Eocene des environs de Paris. III. .Annales de la Societe RoNale Malacologique de Belgique 23:3-324. Page 68 THE NAUTILUS, Vol. 101, No. 2 Cotton, B. C. 1959. South Australian Mollusca. — Archaeo- gastropoda. Handbook of the Qora and fauna of South Australia. Government Printer, Adelaide, p. 449, Dall. \V. H. 1881. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mex- ico, and in the Caribbean Sea, 1877-79, by the United States Coast Survey steamer "Blake", Lieutenant-Com- mander C. D. Sigsbee, U.S.N., and Commander J. R. Bart- lett, U.S.N., commanding. XV. Preliminary report on the Mollusca. Bulletin of the Museum of Comparative Zoology 9(2):33-144. Dall, VV. H. 1885. List of marine Mollusca comprising the Quaternary fossils and Recent forms from .American lo- calities between Cape Hatteras and Cape Roque including the Bermudas. United States Geological Survey, Bulletin 24:1-336. Dall, W. H. 1889a. Reports on the results of dredging, under the supervision of .Alexander .\gassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U.S. Coast Survey steamer "Blake", Lieut-Commander C. D. Sigsbee, U.S.N. , and Commander J. R. Bartlett, U.S.N,, commanding, XXIX. Report on the Mollusca. Part 2, Gas- tropoda and Scaphopoda. Bulletin of the Museum of Com- parative Zoology 18:1-492. Dall, W. H. 1889b. A preliminary catalogue of the shell- bearing marine mollusks and brachiopods of the south- eastern coast of the United States. Bulletin of the United States National Museum 37:1-221. Dall, W. H. 1890. Scientific results of explorations by the U.S. Fish Commission steamer "Albatross". VII. Preliminary report on the collection of Mollusca and Brachiopoda ob- tained in 1887-88. Proceedings of the United States Na- tional Museum 12:219-362. Dall, W. H. 1927. Small shells from dredgings off the southeast coast of the United States by the United States Fisheries steamer "Albatross" in 1885 and 1886. Proceedings of the United States National Museum 70(2667):1-134. Fischer, P. 1885. Manuel de conchy liologie et de paleonto- logie conchyliologique, ou historie naturelle de mollusques vivants et fossiles. F. Savy, Paris, p. 689-896. Goryachev, V, N. 1979. K sisteme glubokovodnikh mollyus- kov semeistva Seguenziidae (Gastropoda). [On the system of the deep-sea molluscan family Seguenziidae (Gastrop- oda).] In: Likharev, I. M. (ed.). Molluscs. Main results of their study. Abstracts of communications. Zoological In- stitute, Akademiya Nauk SSSR, Leningrad, p. 70-71. Jeffreys, J, G. 1877. New and peculiar Mollusca of the Eu- limidae and other families of Gastropoda, as well as of the Pteropoda, procured in the Valorous' Expedition. .Annals and Magazine of Natural History (4)19:317-.339. Johnson, C. W. 1934. List of marine Mollusca of the Atlantic coast from Labrador to Texas. Proceedings of the Boston Society of Natural History 40(l):l-204. Keen, A. M. and L. R. Cox. 1960. [Margaritinae]. In: Moore, R. C. (ed). Treatise on invertebrate paleontology. Part I, Mollusca 1. Geological Society of America, University of Kansas Press, Lawrence, KS, p 1249-125 1. Marshall, B .A 1983 Recent and Tertiar> Seguenziidae (Mol- lusca: Gastropoda) from the New Zealand region. New Zealand Journal of Zoology 10:2.35-262. Martens, E. von. 1881. Mollusca. Zoological Record 16:93 p. Maury, C. J. 1922. Recent Mollusca of the Gulf of Mexico and Pleistocene and Pliocene species from the Gulf states. Part 2: Scaphopoda, Gastropoda, Amphineura, Cephalop- oda. Bulletins of American Paleontology 9(38):34-142. Okutani, T. 1982 Rediscoveries of an abyssal trochid, Basi- lissa superba Watson from the south of Japan. Venus, Japanese Journal of Malacology 40(4):237-239. Pilsbry, H. A. 1889. Trochidae, Stomatiidae, Pleurotomari- idae, Haliotidae. Manual of Conchology. Series 1, Volume 11. Conchological Section, .Academy of Natural Sciences, Philadelphia, PA, p. 519. Quinn, J. P., Jr. 1979. Biological results of the University of Miami Deep-Sea Expeditions. 130. The systematics and zoogeography of the gastropod family Trochidae collected in the Straits of Florida and its approaches. Malacologia 19(l):l-62. Quinn, J. F,, Jr. 1981. A preliminary overview of the Se- guenziidae Verrill, 1884. Bulletin of the American Mala- cological Union for 1980:74 (abstract). Quinn, J. F, Jr. 1983a. Carejuia. a new genus of Seguenziacea (Gastropoda: Prosobranchia) with the descripion of a new- species. Proceedings of the Biological Societv of Washing- ton 96(3):.355-364. Quinn, J. F., Jr. 1983b. ,A revision of the Seguenziacea \'errill, 1884 (Gastropoda: Prosobranchia). I. Summary and eval- uation of the superfamily. Proceedings of the Biological Society of Washington 96(4):725-757, Schepman, M, M, 1908, The Prosobranchia of the Siboga Expedition Part 1 Rhipidoglossa and Docoglossa. Siboga Expedition, Monographic 49'a: 1-107. Thiele, J. 1929-35. Handbuch der systematischen Weich- tierkunde. 2 vols. Gustav Fischer, Jena, p. 1134 Watson, R. B. 1879. Mollusca of H.M.S. "Challenger' Expe- dition. III. Trochidae, viz. the genera Seguenzia, Basilissa, Gaza and Bembix. Journal of the Linnean Societ> of Lon- don, Zoology 14:586-605, Watson, R. B. 1886. Report on the Scaphopoda and Gaster- opoda collected by H.M.S. Challenger during the years 1873-76. Report on the Scientific Results of the Vovage of H.M.S. Challenger, 1873-1876, Zoology 151-680.' W'enz, W. 1938. Gastropoda. Allgemeine Teil und Proso- branchia. In: Schindewolf, O. Handbuch der Palaozoolo- gie. Band 6, Teil 1, Leiferung l&2:l-480 THE NAUTILUS 101(2):69-74, 1987 Page 69 Good Hosts and Their Guests: Relations Between Trochid Gastropods and the Epizoic Limpet Crepidula adunca Geerai J. Vermeij Department of Zoology University of Maryland College Park, MD 20742 USA Richard B. Lowell Department of Zoology Uniyersit)' of Alberta Edmonton, Alberta Canada Linda J. Walters Department of Biology University of South Carolina Columbia, SC 29208, USA Jessica A. Marks Department of Zoology University of Washington Seattle, WA 9S195, USA ABSTRACT The suspension-feeding cal\ ptraeid limpet-like gastropod Cre- pidula adunca (Sowerby ) is found chieQ> on the shells of other gastropods in the temperate northeastern Pacific. In the San Juan Islands (Washington, US.\), its only host is the trochid Calliostoma ligatum (Gould), Experiments in the laboratory showed that Crepidula was protected from predation by the sea-star Leptasterias hexactis by virtue of its close fit on the host shell and by the effective escape response of Calliostoma to sea-stars. The added weight of Crepidula (up to 24*7 of combined weight of guest and host) reduced escape speed and increased the time required for hosts to right themselves after falling in an aperture-up orientation. INTRODUCTION Intimate associations between host and guest species are widespread among bottom-dwelling marine organisms. Such associations — parasitisms, commensalisms, and mu- tualisms— may arise for any of several reasons. In the first place, there are apt to be benefits to the guest. These include a greater and more predictable food supply, greater protection from enemies, and shelter from harsh ph\sical conditions. The suitabilit\ of a given species as host depends on its abundance, defenses against potential enemies, and extent to which it is able to provide benefits. If the presence of the guests improves the host's own performance in coping with surroundings, selection in favor of traits facilitating the association would be es- pecially strong. The present paper is the first in a projected series on the evolution of one widespread but little studied type of intimate association among marine species, that of epizoic limpet-like gastropods living on the shells of other invertebrates. We report here on the association of the temperate northeastern Pacific calyptraeid limpet-like gastropod Crepidula adunca (So\\erb\ ) (hereafter known as Crepidula) with two trochid gastropod hosts, Callios- toma ligatum (Gould) and Tegula funebralis (A. Adams) (hereafter known as Calliostoma and Tegula. respec- tively). Specifically, we investigated the host distribution of Crepidula. the predators of Calliostoma, the effect of Crepidula on the antipredatory performance of its host in the laboratory, and some factors that render Callios- toma an especialK' suitable host for Crepidula. This research was carried out during May and June, 1986, as part of a field course on functional morphology and evolution given at the Friday Harbor Laboratories (Friday Harbor, Washington, USA) by A. R. Palmer and the senior author, with assistance from R. B. Lowell. MATERIALS AND METHODS The distribution of Crepidula among hosts was assessed at several localities in Washington and California. E.x- perimental work was conducted with Calliostoma and Crepidula from Lime Kiln Light (San Juan Island, Wash- ington) and with Tegula and Crepidula from Tatoosh Island (Washington). As a first step in the identification of potential pred- ators of Calliostoma, a field collection of all available "dead shells (either empty or occupied by hermit crabs) was made at Lime Kiln Light. Shells were categorized as intact, lethally broken (the apex removed, the lip bro- ken back, or one or more holes of irregular shape through the shell wall), or drilled, \e.\t, Calliostoma with epizoic Crepidula were maintained in the laboratory with three species of predator that commonly co-occur with Cal- liostoma in the lower intertidal zone. Three crabs (male Cancer ore gonensis Rathbun, 29.0-44.2 mm in carapace width) were maintained for 9 days with 10 Calliostoma each bearing an epizoic Crepidula. Another 30 Callios- Page 70 THE NAUTILUS, Vol. 101, No. 2 toma with epizoic Crepidula were kept w ith 15 Nucella lamelloaa ((jirielin), a drilling muricacean gastropod, for 4 days. The sea-star Leptasterias hexactis (Brandt) in preliminary trials was offered Calliostoma with epizoic Crepidula as well as Crepidula that had been removed from their hosts and allowed to attach to the floor of an acjuariuni before sea-stars were introduced. .\11 subsequent work involving predation concentrated on how Calliostoma protects Crepidula from predation b\ Leptasterias. In the first experiment, 20 Crepidula ranging in apertural length Irom 6.5 to 9.5 mm were removed from their original hosts and transplanted onto 10 living Calliostoma and 10 empty Calliostoma. All Crpp!c/(//a-bearing Calliostoma (18.7-21.8 mm in lon- gest dimension) were then glued to square pieces of Plex- iglas, 3 cm on each side, with Z-Spar (Koppers Company Inc., Pittsburgh, PA 15219, USA), a quick-setting un- derwater epoxy-putty, and placed in an aquarium with 30 Leptaserias (48-78 mm in diameter) for 7 days. Glue was applied to the shell base in such a way that the aperture was oriented obliquely to the floor of the aquar- ium, so that the snail's foot was able to attach to the substratum and capable of reaching the shell's apex. Moreover, the foot v\as free to reach the shell s apex, as would be the case in free-roaming individuals. If differ- ences in the mortality of Crepidula did appear between those on living and empty Calliostoma, they would be accounted for by traits of the host's soft parts and not by the locomotor performance of the host or the precision of the Crepidula' s fit on the host. None of the trans- planted Crepidula had as close a fit on the new host as they did on their original hosts. In order to evaluate how the locomotor performance of Calliostoma affects Crepidula, we ran a laboratory trial for 2 days with 10 glued Calliostoma (16.9-20.8 mm long), 10 free-roaming Calliostoma (16.2-25,0 mm long), and 18 Leptasterias. Each Calliostoma bore a Crepidula (8.5-12.0 mm long) which was found on it in the field and which therefore conformed precisely to the shell contour of the host. The presence of Crepidula potentially influences the escape of the host from slow-moving predators like sea- stars. In this study, we focused on three factors of im- portance in the escape of Calliostoma and Tegula from sea-stars, and on how Crepidula affects the host s escape performance in the laboratory. These were (1) the speed oi flight, (2) orientation of the host on the aquarium floor after the snail is dropped from a vertical surface (a sim- ulation of what happens when the snail drops from the substratum upt)n contact with a sea-star), and (3) the time needed to right the shell if the snail fell with ap- erture (and foot) facing up. Escape speed of Calliostoma and Tegula was mea- sured in an acjuarium at a temperature of 11.5-13.0 °C. .\fter 2 min of acclimation to the aiiuarium, each snail was touched for 3 sec with the tube foot of the sea-star Pycnopodia helianthoides (Brandt) on the cephalic ten- tacles. The snail then reared up, rotated 180°, and began its escape. The speed of escape was measured from the time that flight began. Traces of the snail's movements were drawn on a clear plastic sheet that was taped to the underside of the clear Plexiglas aquarium. String was then placed along the trace, cut, and measured according to the path follov\ ed by the snail for each interval of 30 sec until the snail encountered the w all of the aquarium. Tests were conducted on snails naturalK lacking Cre- pidula, snails with naturally fitted Crepidula whose im- mersed weight in sea-water was less than 10% of the combined weight of host and guest, and snails with nat- urally fitted Crepidula w hose immersed weight account- ed for 10% or more of the total weight of host and guest. Orientation of hosts after falling from a vertical sur- face was assessed for individuals w ith and without Cre- pidula. Snails held as if the\' were clinging to a vertical wall of an aquarium were touched with a tube foot and then allowed to fall through 31.5 cm of water to the bottom. Orientation upon landing w as considered to be either aperture-up or aperture-dow n. Three trials were done on each snail. The time required for snails landing aperture-up to right themselves after a fall was measured for Callios- toma and Tegula with and without epizoic Crepidula. After unsuccessful trials with bottoms of sand, small grav- el, and smooth Plexiglas (substrata on which the snails were unable to right themselves), a 6 mm plastic mesh was used as the substratum on which righting was as- sessed. The holes in the mesh were smaller than the smallest linear dimension of the snail's foot. Righting was divided into two phases: (1) attachment of the foot to the substratum, and (2) placement of the shell over the foot. RESULTS Host Specificity of Crepidlla At the sites we have investigated, Crepidula adunca were found as adults only on the shells of other animals, chieflN' gastropods (Table 1). The trochid Calliostoma ligatum was the only host at San Juan Island, On the outer Pacific coast of Washington and British Columbia, we have also seen C. adunca on Amphissa columbiana (Dall), Sear- lesia dira (Reeve), and Tegula funehralis. Tegula is not found at San Juan Island, but Amphissa and Searlesia are common there; \et they lacked epizoic Crepidula. Calliostoma, some with epizoic Crepidula, is common on the outer Pacific coast together with the other hosts. In the vicinity of Monterey, California, C. adunca is apparentK restricted to Tegula funehralis (see also Put- nam, 1964). Juvenile C. adunca are found on adult Cre- pidula as well as on the other hosts mentioned. Crepidida was the only organism found living on the shells of living Calliostoma. B\ virtue of its ability to extend the foot over the whole shell surface (Harrold. 1982), Calliostoma is apparently able to prevent settle- ment of epizoans other than Crepidula (figure 1). Shells of Calliostoma occupied b\ hermit crabs ha\e a variety of epizoans, including small limpets (Tectura scutum G J. Vermei] et ai. 198" Page 71 Table 1. Occurrence of Crepidnla adunca on hosts at various sites in the northeastern Pacific Inci- dence Locality and host N {%) San Juan Islands, Washington, May-June, 1986 Lime Kiln Light Calliostoma ligatum (Gould) 179 41 Hermit crabs in C ligatum 74 3 Searlcsia dira (Reeve) 36 0 Amphissa columhiana (Dall) 8 0 Margarites pupillus (Gould) 24 0 Nucella lamellosa (Gmelin) 26 0 Peavine Pass, 10 fathoms C. ligatum 20 55 A. Columbiana 20 0 Rock Point, 40 fathoms C. ligatum 31 0 Amphissa spp. 97 0 Trichotropis canccllata (Hinds) 111 0 Margarites spp. 11 0 Hermit crabs 109 0 Central California, March, 1980 Pacific Grove, intertidal Tcgula funebralis (A. Adams) 89 26 T. brunnca (Philippi) 50 0 Other gastropods 100 0 Eschscholtz and Acmaea mitra Eschscholtz), barnacles, serpulid pol\chaetes, and the bryozoan Tiibulipora sp. Tegula does not extend its foot up to the shell ape.x, and apparently cannot prevent settlement of epizoans on the outer shell surface. Of 22 living T. funebralis from Ta- toosh Island, seven (32?o) bore Crepidula and nine (41%) bore serpuiids, barnacles, or coralline red algae. Three individuals bearing Crepidula also had other epizoans growing on the shell. Crepidula itself also carried various combinations of corallines, br\ozoans, and serpuiids. Predators of Calliostoma An analysis of "dead" shells of Calliostoma from Lime Kiln Light suggested that drilling is not a cause of death, and that breakage ma\ be less common than those forms of death that leave the shell intact. Of 78 shells collected, 61 (78%) were intact and 17 (22%) were lethally broken. The proportion of broken shells may have been under- estimated owing to the fact that apical fragments may have been lost quickly from the supply of shells available to hermit crabs. Laboratory trials indicated that the crab Cancer or- egonensis is a potential predator of both Calliostoma and Crepidula. Over a 9-da\ period, three out of 10 Calliostoma. as well as three out of 10 Crepidula epizoic on the victims, were eaten bv the three male crabs. The Figure 1. Crepidula adunca epizoic on Calliostoma ligatum from Lime Kiln Light, San Juan Island, Washington. Photo- graph by R.B.L. broken shells of Calliostoma closely resembled the dam- aged "dead" shells collected at Lime Kiln Light. None of the 30 Calliostoma maintained with 15 Su- cella lamellosa for 4 days was eaten. This finding cor- roborated the field evidence that Calliostoma was not drilled. Several sea-stars include Calliostoma in their diet and leave the shell intact after the prey is consumed. They include Pycnopodia helianthoides (Shivji et ai, 1983), Orthasterlas koehleri (Mauzey et ai, 1968), Stijlasterias forreri (Mauzey et al.. 1968), Pisaster giganteiis (Har- rold, 1982), and Leptasterias hexactis (Hoffman, 1981). Calliostoma has well-developed escape responses to these sea-stars (Hoffman, 1981; Harrold, 1982). We concen- trated our work on Leptasterias. which attacks its prey by everting the stomach into the aperture and digesting the flesh externally. Not only is Leptasterias abundant in the low intertidal habitat of Calliostoma, but in pre- liminary trials this sea-star ate naturally fitted guests as well as their hosts that had been confined with Leptas- terias in mesh cages under water. We suspected that a good fit of the guest on the host, together with the hosts escape reaction, protected Crepidula from predation by sea-stars. Trials with 10 Crepidula-hearing free-roaming Cal- liostoma kept with six Leptasterias for 7 days resulted in the predation of four hosts and no guests. In another trial, three Leptasterias during a 16-hr period ate four of eight Crepidula that had been allowed to attach to the floor of an aquarium after being remo\ed from their hosts. Imprecisely fitted Crepidula apparently gained no Page THE NAUTILUS, Vol. 101, No. 2 Table 2. Escape speeds of Calliostoma ligatum in response to contact with the sea-star Pycnopodia. Snails that were used either bore naturally fitting Crepidula or were found in the field to lack epizoic Crepidula. Table 3. Effect of Crepidula on landing orientation of hosts after the latter fall from a vertical surface. Category Trials Escape speed (cm/sec) with SD Crepidula lacking Crepidula less than 10% of total weight Crepidula greater than 10% of total weight 0.34 ± 0.037 0.32 ± 0.022 (1.27 ± 0.070 protection from sea-stars b\ their association with living Calliostoma if the latter were unable to escape. In the experiment with transplanted Crepidula on living and empt) Calliostoma. mortaiitv' of Crepidula was the same (five of 10 individuals) whether the host shell was empty or contained a living snail. In addition to preying on Crepidula, Leptasterias ate seven of 10 living Callios- toma. The effects of a close fit and of the host s escape were further demonstrated by the pattern of attack by sea- stars in the experiment with immobile (glued) and free- roaming CrepiV/u/a-bearing Calliostoma. After the first 9 min of the experiment, nine of 10 free-roaming hosts had already crawled from the floor of the aquarium to just above the surface of the water on the vertical walls of the aquarium. Of the 10 Calliostoma attacked by Leptasterias during the first 4 hr of the experiment, eight were immobile and onl\ two were free-roaming. This difference was significant at the 0.05 level (two-by-two contingency test). After 2 days, Leptasterias had con- sumed seven of 10 glued Calliostoma, three of 10 free- roaming Calliostoma, and none of the Crepidula. Escape was not the only defense of Calliostoma against Leptasterias. Of the 42 cases of subjugation of Callios- toma by Leptasterias that we witnessed, at least 19 (45%) were unsuccessful. The latter figure is almost certainly an underestimate, because we were unable to monitor the animals continuously. In the 19 unsuccessful attacks, Leptasterias was found to be humped over the prey and to have extruded the stomach into the aperture in the usual way, but the sea-stars were unable to push aside Percent landing aper- ture- Category Trials down Calliostoma with Crepidula Calliostoma from which Crepidula were removed 180 132 23% 10% Calliostoma naturallv without Crepidula Tegula with Crepidula Tegula from which Crepidula were removed 39 21 4.5 21% 5% 18% the tightly fitting operculum of the retracted gastropod. When the sea-stars released the Calliostoma, the latter remained withdrawn for some time before resuming nor- mal crawling activity. The average time required for Leptasterias to subdue and consume Calliostoma was 2 days. Effect of the Guest on the Host Crepidula could have several detrimental effects on its host. In the first place, it adds substantial weight to the animal. Crepidula accounted for a mean of 10.2 ± 5.3% of the immersed weight of the host and guest combined (range 1.0-23.8%', n = 57). For Tegula and Crepidula. the mean contribution of Crepidula s immersed weight was 7.3% (range 0.9-16.0%, n = 7). The added weight of Crepidula could reduce the lo- comotor performance of Calliostoma during escape at- tempts from sea-stars. Compared to individuals lacking Crepidula. Calliostoma with a load of Crepidula greater than 10% of total immersed weight moved 20% less rap- idly upon being touched by a tube foot of Pycnopodia (p < 0.05, see Table 2). Calliostoma with a moderate load (less than 10% of immersed weight) of Crepidula moved at intermediate speeds, but did not differ statis- tically from the heavily weighted or the Crepidida-iree snails. Data in Table 3 on landing orientation indicate that Table 4. Effect of epizoic Crepidula on the time required by hosts to right themselves after landing aperture-up Differences between Calliostoma with and without Crepidula were statistically significant at p < 0,001 for both the foot-attachment (first) and shell-positioning (second) phases of righting. For Tegula. differences for the first iihase and for the righting process as a whole were significant at p < 0.02. Time in seconds with SD Category Trials Phase 1 Phase 2 Calliostoma with Crepidula Calliostoma without Crepidula Tegula with Crepidula Tegula without Crepidula 180 132 21 28 82 ± 185 34 ± 21 774 ± 257 527 ± 420 6.2 ± 11 1.2 ± 1.2 0.24 ± 0.77 0 84 ±0 44 G. J. Vermeij ct ai, 1987 Page 73 epizoic Crepidula had an inconsistent effect on its host. The chance of the host s landing aperture-down, en- abling the snail to begin crawling aw ay sooner, was great- er for Crcpiclula-hfdnng CaUioHtoma than for indi\id- uals whose Crepidula were removed, but snails naturally lacking Crepidula had the same rather high probability of landing aperture-down as did individuals with epizoic Crepidula. Tegula w ith Crepidula were less likeK to fall aperture-down than were indi\iduals without epizoic Crepidula. The time required for hosts to right themselves after landing in an aperture-up position was significantK greater in individuals bearing Crepidula than in those same individuals from which the Crepidula had been removed (Table 4). In Calliostoma. this was true for both the foot-attachment and the shell-positioning phases of the righting process, whereas in Tegula the pattern was due entirely to the first (foot-attachment) phase. The presence of Crepidula increased the time of righting by factors of 2.5 and 1.5 in Calliostoma and Tegula. re- spectively. DISCUSSION Our study of Crepidula adunca showed that this species is more or less specialized to live as an epizoan on the shells of living gastropods. Hoagland (1977a) reported that the species has also been collected from the surfaces of subtidal stones, but we have never found C. adunca on substrata other than the shells of gastropods and a few hermit crabs despite extensive dredging on all tvpes of bottom in the San Juan Islands. In its apparent restriction to the shells of other animals, C. adunca resembles the tropical Eastern Pacific C. incurva (Broderip), but the latter species is found on many gastropod hosts as well as on hermit crabs (Vermeij, unpublished data) whereas C. adunca is apparently absent from most potential host gastropods with which it lives in the lower intertidal and subtidal zones. The eastern North American C. convexa (Sa\ ) ma\' live on the shells of gastropods (Hoagland, 1977b), but it is more common on shells occupied by hermit crabs (Karlson & Cariolou, 1982; Shenk & Karl- son, 1986), and also frequently adheres to stones and sea- grasses (Hoagland, 1977a, b). Among species that have been ecologicalK characterized, therefore, C. adunca ranks as one of the most specialized w ith respect to the range of substrata occupied. As sedentarv- filter-feeders, adult Crepidula would in general be highK- vulnerable to many kinds of predators, as well as to competitors and physical calamities. Species that characteristically live on exposed surfaces of stones or rocks tend to be large, thick-shelled, and sometimes spiny, whereas most species (except C. incurva) living on the outer or inner surfaces of shells tend to be small and thin-shelled. That shells provide a refuge from pred- ators is suggested by our data. Although C. adunca that were artificially removed from their host readiK fell victim to Lcptasterias, epizoic individuals were rarely eaten by this predator by virtue of the effective escape responses of Calliostoma ligatum, one of its chief hosts. A similar benefit of living on the shells of mobile trochids (Austrocochlea constricta Lamarck) was demonstrated by Mapstone et al. ( 1984) in experiments with the grazing epizoic lottiid limpet Patelloida niufria (Hedley) in New- South Wales, but in this case the chief predator was the muricacean gastropod Morula marginalba (Blainville). Our results may be criticized for having been obtained under controlled laboratorv conditions rather than in the field. We believe, however, that the types of field ex- periment used by Mapstone et al. (1984), in which lim- pets w ith and w ithout host snails were maintained with and without predators in cages, introduce the same kinds of limitations that are imposed by conditions in the lab- oratory. Another objection — our lack of replication of some of the experiments — was forced upon us by insuf- ficient time. We do not know if Crepidula gains an)- substantial protection from its hosts in encounters with other pred- ators. Preliminar>' trials showed that Calliostoma as well as epizoic Crepidula were attacked successfullv bv the crab Cancer oregonensis. Our data indicate clearly that the presence of Cre- pidula decreased the locomotor performance of hosts during escape attempts from sea-stars. To what extent the decrease in escape speed and the increase in the time required for righting the shell after a fall place Callios- toma and Tegula at greater risk to predation in the field cannot be determined at present. In a similar case, Schmitt et al. (1983) showed that when the Californian trochid Norrisia norrisi (Sowerby) attempted to escape from Pi- saster giganteus, its escape velocity was decreased in the presence of the epizoic barnacle Megabalanus califor- nicus, and that this decrease resulted in a higher success rate for Pisaster. It is likely that weight rather than drag is responsible for the decrease of the snails locomotor performance in the presence of epizoic Crepidula. At the relatively low velocities of most gastropods, drag is low (Palmer, 1980). Crepidula ma} benefit from its association with snails in wa>s that we did not investigate. The fact that Cal- liostoma ligatum is capable of cleaning its shell and laying down a thin film of mucus on the outer shell surface suggests that settlement of potential competitors such as bryozoans, barnacles, and algae is usually pre- vented. How juvenile Crepidula are able to settle and stay on Calliostoma when the latter's foot is extended over the shell is not known. It is also possible that the mucus may contribute to, or help trap, Crepidula s food supply. A possible benefit of Crepidula for its hosts is that it increases the effective size of the host, so that potential predators would have greater difficulty in sub- duing the host. A potential disadvantage of the associa- tion to Crepidula is that the guest is exposed to desic- cation and is prevented from feeding when the host crawls out of water. A similar disadvantage was noted by Mapstone et al. (1984) for Patelloida mufria on Aus- trocochlea constricta. but in that case the limpet tended to be found chiefl\' on the underside of the host's shell Page 74 THE NAUTILUS, Vol. 101, No. 2 where the guest is less at risk to desiccation, whereas in the present instance the guest often occurs on the upper surface of the shell. Adult (female) Crepidula are sed- entary, and are therefore incapable of moving to the safer underside of the host. Compared to other species in its size range, Callios- toma ligatum is the fastest among the low intertidal gastropods in the San Juan Islands (Miller, 1974). This fact suggests that other potential hosts would pose greater risks for epizoic Crepidula. We do not know why Sear- lesia and Amphissa serve as hosts on the outer Pacific coast whereas they are not occupied by Crepidula in the San Juan Islands. Searlesia seems to be avoided by sea- stars, and it would therefore seem to be a good host for Crepidula wherever it occurs; but the animal is very slow, it extends higher into the intertidal zone than does Calliostoma, and its shell is extensively grazed by small patellacean limpets. Although mobility of the host may be an important attribute protecting epizoic Crepidula and some other limpets such as Patelloida nnifria, it may have little to do with the choice of hosts by other epizoic limpets. What these other attributes might be and how they vary geo- graphically are interesting questions for future investi- gations. ACKNOWLEDGEMENTS We thank the Friday Harbor Laboratories for providing research facilities and a stimulating environment, and Elaine Hoagland and Ronald Karlson for reviewing the manuscript. LITERATURE CITED Harroid, C. 1982. Escape responses and prey availability in a kelp-forest predator-prey system. American Naturalist 119:132-135. Hoagland, K E. 1977a. Systematic review of fossil and Recent Crepidula and discussion of evolution of the Calyptraei- dae. Malacologia 16:353-420. Hoagland, K. E. 1977b. A gastropod color polymorphism: one adaptive strategy of phenotypic variation. Biological Bul- letin 152:360-372. Hoffman, D. L. 1981. Defensive responses of marine gastro- pods (Prosobranchia, Trochidae) to certain predatory sea stars and the dire whelk, Searlesia dira (Reeve). Pacific Science 34:231-243. Karlson, R. H and M. A Cariolou. 1982. Hermit crab shell colonization by Crepidula cotivexa Say. Journal of Exper- imental Marine Biology and Ecology 65: 1-10. Mapstone, B. D., A. J. Underwood, and R. G. Creese. 1984. Experimental analyses of the commensal relation between intertidal gastropods Patelloida mufria and the trochid Aiistrocochtea constricta. Marine Ecologv Progress Series 17:85-100. Mauzey, K. P., C. Birkeland, and P. K. Dayton. 1968 Feeding behavior of asteroids and escape responses of their prey in the Puget Sound region. Ecology 49:603-619. Miller, S. L 1974. Adaptive design of locomotion and foot form in prosobranch gastropods. Journal of Experimental Marine Biology and Ecology 14:99-156. Palmer, A. R. 1980. Locomotion rates and shell form in the Gastropoda: a re-evaluation. Malacologia 19:289-296. Putnam, D. ,\. 1964. The dispersal of young of the commensal gastropod Crepidula adunca from its host, Tegula june- bralis. The Veliger 6(Suppl.):63-66. Schmitt, R. J., C. W. Osenberg, and M. G. Bercovitch. 1983. Mechanisms and consequences of shell fouling in the kelp snail, Norrisia norrisi (Sowerby) (Trochidae): indirect ef- fects of Octopus drilling. Journal of Experimental Marine Biology and Ecology 69:267-281. Shenk, M. A. and R. H. Karlson. 1986. Colonization of a shell resource by calyptraeid gastropods: tests of habitat selec- tion and preemption models Journal of Experimental Ma- rine Biology and Ecology 99:79-89. Shivji, M., D. Parker, B. Hartwick, M. J. Smith, and N. A. Sloan. 1983. Feeding and distribution study of the sunflower sea star Pycnopodia helianthoides (Brandt, 1835). Pacific Sci- ence 37:133-140. THE NAUTILUS 101(2):75-79, 1987 Page 75 Distribution, Abundance, and Movement Patterns of Shoreline Chitons of the Caribbean Coast of Mexico Charles W. Randall Robert F. Martin Texas Memorial Museum and Department of Zoology The Universit\ of Texas at Austin Austin, TX 78705, USA ABSTRACT Observations of relative numbers, wet weight, distribution, and movements of Chiton squamosus and Acanthopletira granu- lata were made during 1983 and 1984 along unsubmerged, wave-washed portions of the rocky shorelines of Akumal and Tulum, Quintana Roo, Mexico. Incidental, less detailed data are presented for Chiton marmoratus, Ceratozona squalida. and Chiton tuberculatus. Chiton sqtiamosus was most abun- dant at Tulum in exposed, wave-washed situations well above mean sea level; A, granulata occurred in lower, more protected areas, and was most common in shore-margin pools at Akumal Chiton marmoratus was less common than the former two species, and usually occurred in areas exposed to wave action in three morphotypes, Ceratozona squalida and C. tubercu- latus were uncommon above mean low water level. Numerical densities of C. squamosus ranged from 0.3/m- to 13.9/m-, depending upon habitat type; biomass densities ranged from 0.3 g, m- to 28.2 g/m-. Numerical density of A. granulata ranged from O.l/m- to 16.4/ m-, biomass densit\ from 0 g/m- to 54.9 g/m-. Jul) and December size distributions and total numbers are presented for C. squamosus and A. granulata at four subsites of each major research area. Numbers of C. squa- mosus at three Tulum subsites were reduced following severe summer storms. Movements of both C. squamosus and A. gran- ulata were primarily nocturnal, although some individuals of each were active diurnalK'. Nocturnal movement b\ individual chitons usualK w as discontinuous. Comparison of total distances moved with total displacements from original sites suggested tendencies to travel within restricted areas. INTRODUCTION Although the marine invertebrates of the Caribbean Sea have been studied with considerable intensity, reports dealing with the invertebrate fauna from the north- western shores of these waters are relatively scarce. Re- search on chitons reflects this situation well; although a number of works on various aspects of the biologv of West Indian species exist (see Glynn, 1970, for refer- ences), the species of the western shores of this sea have been relatively neglected and t\ pically are represented casualK in publications dealing with general moUuscan faunas (e.g., Weisbord, 1926; Jaume, 1946; Hidalgo, 1956; Yokes, 1983). Here, we list the chitons of the rocky shore- line of a restricted segment of the eastern coast of the Yucatan Peninsula and discuss in preliminary fashion various aspects of the ecology of Chiton squamosus and Acantbopleura granulata, the two most common chitons there. STUDY AREA AND METHODS Our study sites are at Akumal (20°24'N, 87°18"W) and Tulum {20°13'N, 87°26"W), Quintana Roo, Mexico. In this area, sandy embayments alternate with rocky headlands of dark limestone, eroded remnants of Pleis- tocene reefs. Fringing, live reefs lie from several hundred to nearly a thousand meters offshore. During much of the \ear, the easterly tradewind sweeps the coast; vari- ations in water level at the shoreline appear to be more a function of wind velocity and direction than that of the minor semidiurnal tidal changes (less than 0.3 m; data from tide tables for Key West, Florida, USA cor- rected for Belize City, Belize, 325 km S Akumal) that occur along this coast. At Akumal, a shallow (maximum depth 1.5-4 m), cres- centic bay approximately 1 km broad and 500 m deep is protected at its seaward boundary by a living coral reef. The flanking, northern margin of the bay is a flat, weathered Pleistocene reef-limestone headland, frag- mented at its seaward fringe, and rising shallowly from sea level at its outer edge to only several meters above sea level at its junction with the forebeach. In 1983, six pools (subsites) were selected from along the seaward margin of this headland for surveys of numbers and densities, and for observations of movements of chitons; only data from four of these are presented here. All were within 10 m of the sea margin and were filled and drained by wave action for at least part of each da\'. In some areas of these pools, chitons were exposed to conditions of drying and direct sunlight. Crude measurements along the longest axis of each pool and along the longest axis perpendicular to this were taken; in addition, two pools Page 76 THE NAUTILUS, Vol. 101, No. 2 were measured more accurately and were drawn to scale on graph paper to allow calculations of chiton densities. Pool 1 measured 7.0 x 4.6 m; Pool 3, 1 1.6 x 1.8 m; Pool 5, 7.3 X 4.6 m; Pool 6, 4.3 x 2.7 m. Water depth within pools usually ranged from less than 0.3 m to approxi- mately 0.8 m. During the storms of July 2-18, 1983, pools frequentK were totalK' immersed by the sea for several hours to longer than one da> . Various pools were surveyed for size class, numbers, and species of chiton on July 20 and December 15, 1983; other, less detailed surveys were made prior and subsequent to these dates. .\t the Tulum site, the coast is sublinear; steep lime- stone cliffs (remnants of the Pleistocene reef) rise directly from the sandy bottom, or from a litter of very large to small breakdown boulders. A fringing reef lies approx- imately 0.5 km offshore. Horizontally, much of the cliff base and breakdown is below water for most of the day and wave splash usually precludes drying. A zone of multicellular reddish- to greenish-brown adherent algal vegetation coats the lowest portions of most cliff faces and breakdown rubble from the sandy bottom extending upward from several cm to 1.2 m. On this (windward) coast, the vertical limit of this vegetation probably is the product of a number of physical (wind direction and intensity, mean and extreme low tide, etc. ), and possibly, also, biotic factors (Duggins and Dethier, 1985). At Tulum, the plane of the upper level of this algal zone served as our major vertical reference point. Lack- ing calm conditions during the stud>, we could not de- termine tidal stands here with accuracy, but feel that the zone's upper level more nearly approximates mean high, rather than mean low, water level. Chitons were far more numerous above (up to 1.8 m above the sandy substrate) than within this vegetation, and only those above and a few easily visible within the upper 30 cm of the zone were counted in our surveys. Constantly submerged areas were not examined for presence of chi- tons during this stud\ . Seven subsites were selected along cliff bases and breakdown rubble; only data for four of these are pre- sented here. Subsite 1 was a moderate-sized, deeply pit- ted boulder of irregular shape, separated by 1 m from an adjoining rock. Its base was completely submerged to a depth of 0.3-0.6 m at most times; its top usually ex- tended 0.6-0.9 m above sea level, and its circumference at the upper macro-algal limit was approximately 12.2 m. .Approximately 75% of its exposed (all but its upper- most) surface was inhabited by chitons. Subsite 2 was an undercut cliff face just N of Subsite 1; approximately 14.3 m of its length was surveyed for chitons. Subsite 5 was a very large, slab-sided boulder separated from other rock surfaces by at least 3 m of sand; most (all but the farthest backside) of its lower circumference was inhab- ited by chitons; this 28.7 m was surveyed. Subsite 7 was an isolated rock just S oi Subsite 5 and surrounded b\ sand; 12.2 m of its circumference were surveyed. Subsites 1-7 were surveved on Julv 20 and 21 and December 13, 1983. Prior to survey and movement studies, six size classes of chitons were erected as follows: Class 1, those less than 1.27 cm from anterior to posterior tips of girdle; Class 2, those from 1.27 to 2.53 cm; Class 3, 2.54-3.80 cm; Class 4, 3.81-5.07 cm; Class 5, 5.08-6.34 cm; Class 6, 6.35-7.61 cm. To crudely assess biomass, wet weights were taken for five specimens of each species from each of the three size classes which held the greatest number of individuals of that species. Chitons were removed from substrate, blotted dry with a soft cloth, and weighed to the nearest 0. 1 g with a Pesola spring balance. .After weighing, shell plates were removed from an additional sample of eight formalin-preserved chitons, and weigh- ings were repeated to determine ratios of wet soft part weight to total weight. These ratios were utilized in final calculations of biomass densities. To investigate movement patterns, indi\ iduals of each species were marked with small spots of quick-drying paint and their locations were noted. One to several re- turn visits were made to determine if movement had occurred from the original location of each. .\t Tulum on June 28, six C. squamosus clinging in relatively ver- tical wave-splashed areas were marked during the period 0545-0750 hr; all were checked near 1700 hr and one was checked twice additionally at 0700 hr on June 28 and at 0600 hr on June 29. At Akumal on July 18, 1983, nine A. granulata were marked near 1000 hr and were checked for displacement from original sites twice sub- sequently on that date; three additional individuals were marked at 0215 hr and checked near 1700 hr. .A full dark to davlight vigil was maintained during the night of July 28-29, 1983 (Akumal Pool 2, 2015-0545 hr) to monitor nocturnal movements of both species; a less thor- ough vigil was undertaken during the night of JuK 1-2, 1984 at .Akumal Pool 3 to gain additional data. On both nights, movements were checked at 15-min intervals. Voucher specimens of the fi\e species of chiton en- countered are deposited in the Recent Invertebrate Col- lection of the Texas Memorial Museuni-The University of Texas at Austin: C. squamosus, 1574TX1; .4. granu- lata. 1574TX2; Chiton marmoratiis, 1574T\3, 1574T.\4, 1574TX5; Ceratozona squalida. 1574TX6; Chiton tii- berculatus, 1574TX7. RESULTS Distribution: Chiton squamosus is most numerous in areas exposed to wave action; at Tulum, most adhere to vertical surfaces above the level of the multicellular algae and are kept moist by wave splash or inundation. Here, Acanthuplcura granulata occurs in lower, more shel- tered or concealed locations, among the cre\ ices of cliff breakdown rubble, closer to, and sometimes within the algal zone. Chiton marmoratiis occurs in three color morphs (.Abbott, 1974) and at lower frequenc> at Tulum than C. squanwsus and .A. grauuUita, but still is relativ cK common; it represents less than 20% of the entire chiton population here. The reddish morph of C. marmoratus is far less common here than the light and dark morphs. The distribution of this species is similar to that of C. C. W, Randall and R. F. Martin, 1987 Page 7' Table 1. Numbers of Chiton sqtiamosus and Acanthopleura grantilata at four Tulum subsites on July 20 and December 13, 1983. Size class Subsi ite 1 Sl: ibsite .1 Su ibsite 5 Subsite 7 Species Jul, Dec Jul. Dec Jul. Dec Jul Dec. C. sqiiamosus 1 1 0 0 — 4 — 0 1 2 8 0 12 — 32 — 22 18 3 20 17 36 — 68 — 42 86 4 25 38 52 — 57 — 35 68 5 0 3 0 — 0 4 3 6 0 0 0 — 0 — 0 0 Total 54 58 100 — 161 — 103 176 A. granulata 1 3 0 0 — 0 — 0 0 2 7 0 0 — 2 — 2 0 3 6 0 5 — 2 — 0 0 4 4 ( 11 — 3 — 0 0 5 6 6 4 — 0 — 0 0 6 0 1 1 — 0 — 0 0 Total 26 14 21 — 7 — 0 0 December surveys not performed at Subsites 2 and 5. squamosus, but somewhat closer to the top of the algal zone. Ceratozona squalida occurs within, and occasion- ally above, the zone of algae and forms less than 1*^ of the non-submerged population visible at this site. Chiton luberciilatus is rare; only two were encountered during our surveys. On the relatively exposed vertical rock faces and rub- ble at Tulum, C. squamosus was more common than A. granulata (table 1), although the cryptic distribution of A. granulata here results in some degree of underesti- mation of its abundance. In the shelf-margin pools at Akumal, A. granulata was far more common than C. squamosus (table 2). No additional species of chiton were observed here. Just beyond the seaward entries and spill- ways of these pools, in alternately exposed and inundat- ed, heavily surf-swept areas not surveyed, C. squamosus were more numerous, and A. granulata decreased in frequency. Biomass: Mean \\et weights per most common size classes (x ± SE) of C. squamosus were: Class 2, 0.68 ± 0.08 g; Class 3, 1.98 ± 0.23 g; Class 4, 6.28 ± 0.21 g. Those for A. granulata were: Class 3, 4.06 ± 0.35 g; Class 4, 8.94 ± 0.29 g; Class 5, 11.40 ± 0.92 g. Ratios of wet soft part weight to total v\ eight were: C. sqiia- nwsus. 0.50; A. granulata, 0.43. Density: Numerical density data for both species were calculated (table 3) and reflect those presented previously for numbers (tables 1, 2) at both sites. Inter-subsite dif- ferences in numerical density (table 3) are more pro- Table 2. Numbers of Chiton squamosus and Acanthopleura granulata at four .Akumal subsites on July 20 and December 15, 1983.' Size class Subsite 1 Subsite 3 Subsite 5 Subsite 6 Species Jul, Dec Jul Dec. Jul Dec Jul Dec C squamosus 1 0 0 0 — 0 — 0 0 2 0 1 0 — 1 — 1 7 3 4 12 8 — 15 — 6 8 4 0 5 1 — 7 — 2 1 5 0 0 0 — 0 — 0 0 6 0 0 0 — 0 — 0 0 Tot. 4 18 9 — 23 — 9 16 A. granulata 1 0 1 0 — 0 — 0 0 2 3 2 1 — 1 — 4 9 3 36 24 82 — 9 — 39 78 4 148 124 269 — 120 — 135 117 5 16 5 1 — 15 — 5 2 6 4 0 0 — 0 — 0 0 Tot. 207 156 353 — 145 — 183 206 ' December surveys not performed at Subsites 3 and 5. Page 78 THE NAUTILUS, Vol. 101, No. 2 Table 3. Numerical density (individuals/ m-) and biomass density' (g, m'; in parentheses) for Chiton squamoHus and Acanthopleura granulata at Tulum and Akiniial .subsites on July 20 and December 13 or 15, 1983 Sub- Ju y 20 December 13 or IS- C. squa- A. gran- C', sqtia- A. gran- Site site mosus ulata mosus ulata Tulum 1 7.5 3.8 8.1 1.9 (14.0) (7.7) (18.9) (7.8) 2 13,9 2.9 — (28.2) (9.8) — — 5 4.3 0.2 — (6.8) (0.4) — — 7 7.6 0.1 12.9 0 (11.7) (-) (22.4) (0) .\kunial 1 0.3 15.6 1.4 11,7 (0.3) (53.4) (2.1) (40,8) 3 0.4 16.4 (0.5) (54.9) — — ' Biomass densities are based only on size classes 2, 3, and 4 for C, squamosus and 3, 4, and 5 for A. granulata. hence are conservative (see tables 1 and 2 to assess unincluded specimens), - Tulum surveyed December 13; Akumal, December 15, nounced at Tulum than at Akumal due to the greater amount of habitat diversity (degree of exposure versus shelter) here; biomass densities in g/m- also reflect this relationship (table 3), Size distribution: At both Tulum and Akumal, individ- uals of size Class 4 usually were the most comnnon A. granulata during July and December surveys (tables 1, 2), At Akumal, individuals of Class 3 were the most common C. squamosus in both surveys (table 2); at Tul- um, C. squamosus of Class 3 were most common during three surveys, while those of Class 4 were most common in three other surveys (table 1), Storm effects: A number of storms with severe easterly winds struck our sites during the period of July 2-18, 1983; that on July 16 was particularly severe. Percentage losses of C, squamosus at three Tulum subsites between JuK 7, the date of preliminarv surveys at several subsites, antl JuK 20, 1983 (table 1), the date of our main survey, were: Subsite 2, 32%; Subsite 5, 27%; Subsite 7, 29%. By December 13, 1983, the population of C, squamosus at Subsite 7, one of two subsites at Tulum surveyed then (table 1), exceeded that of the July 20 survey by 71% and that of the July 7 preliminary survey by 20%. Pop- ulations of A, granulata at these sites were too small to use in loss estimates (table 1), Movements: Diurnal displacements of C, squamosus marked on June 29 were as follows: Chiton 1) 0715-1700 hr, 35,6 cm; 2) 0715-1700 hr, 0 cm; 3) 0750-1705 hr, 10,2 cm; 4) 0750-1705 hr, 5.1 cm; 5) 0750-1715 hr, 11.4 cm; 6) 0545-0700 hr, 48.3 cm; 0700-1705 hr, 91.4 cm; 1705-0600 hr, 170 cm. Diurnal displacements of A. gran- ulata marked on July 18 were as follows: 1) 1000-1350 hr, 7,6 cm; 1350-1710 hr, 0 cm; 2) 1000-1350 hr, 2,5 cm; 1350-1710 hr, 99,1 cm; 3) 1000-1350 hr, 0cm; 1350- 1710 hr, 0 cm; 4, 5, 6) 1015-1430 hr, 0 cm; 1430-1725 hr, 0 cm (all three individuals); 7) 1415-1710 hr, 7,62 cm; 8, 9) 1415-1710 hr, 0 cm. General observations of C. squamosus at Tulum and of A, granulata at Akumal during census periods also indicated that individuals of the former species were more likely to be in motion during daylight than those of the latter. Distributive statistics for total time observed, total dis- tance moved, and rate of travel are presented by species and size class for the 1983 nocturnal movement survey in table 4. Individuals of both species moved discontin- uously; some remained motionless for more than an hour between bouts of movement; none were active contin- uously through the night (table 4). Sample sizes were small and did not permit confident comparisons between species or size classes. Displacement ol individual chitons from place of initial observation to place of final obser- vation usually was considerably less than 30% of total distance traveled; this suggested either a lack of strongly directional movement or a weak tendency to remain within a home "range". In 1984, distances travelled and rates of travel for 6 C. squamosus were approximately 50% those of 1983; those for A. granulata were less than 33% of those in 1983. Table 4. Distributive statistics for nocturnal movements of Chiton squamosus and Acanthopleura granulata at ,\kumal Subsite 2 on July 28-29, 1983, during 2015-0545 iir. Size class N Time in motion (hr)' Distance moved (cm) Rate (cm. hr) Species X SE X SE X SE C, squamosus A. granulata 3 4 2 4 5 4 5 2 2 2 6,68 7,25 7.13 8.00 7,00 0,66 0.41 0,37 1,25 2.50 106.04 30.89 108.97 18.27 194.31 24.13 124.46 68.59 262.89 14100 16.92 15.14 27.53 17.32 34.80 5.65 2.33 4.84 11.28 7.71 .•\ 15 min period m w hicli motion occurred was scored as full 15 nun of motion; tiuis time in motion is an overestimation of actual activitv. C. W, Randall and R. F. Martin, 1987 Page 79 DISCUSSION Few works of direct ecological bearing exist for com- parison with this study (Glynn, 1970; Kangas & Shep- herd, 1984; Duggins & Dethier, 1985; Otaiza k Sante- llces, 1985). Glynn (1970) found A. granulata to be the chiton that occurred highest on the shore in Puerto Rico as did Lewis (1960) at Barbados; these authors did not discuss C. squamosus. At Tulum, when the shoreline structure permitted comparisons, A. granulata occupied a physical niche similar to those reported by Lewis (1960) and b\ Glynn (1970), but o\erlapped approximately the lower 0.3 m of the habitat of C. squamosus. which oc- curred considerably higher and was considerably more numerous at the study site here (table 1). At Akumal, the study site was not comparable physically with those at Puerto Rico, Barbados or Tulum, but A. granulata occurred in greater numbers than C. squamosus (table 2) in situations that were more protected from wave action. Here, but not at Tulum, A. granulata occurred in numerical densities (table 3) approaching those re- ported by Glynn (1970), suggesting that the presence of C. squamosus may serve to limit the numbers or modify (toward crypticity) the distribution of A. granulata on Tulum's vertically disposed shorelines. At our sites (table 3), neither chiton reached densities of the four most common intertidal chitons studied in Chile by Otaiza and Santelices (1985), but the average sizes of each of those four species were considerably smaller than those of each of ours (tables 1, 2). The range of densities of a variety of subtidat Australian chitons examined by Kan- gas and Shepherd (1984), with a single exception, fell within that of densities of C. squamosus and A. granulata at our study sites (table 3). Chiton marmoratus was con- siderably more numerous at the Tulum site than at Glynn's Puerto Rican stud\ area (1970) and, on the unsubmerged portions of the shoreline at Tulum, occurred higher than A. granulata. rather than lower, as at Barbados (Lewis, 1960). Both Chilean (Otaiza & Santelices, 1985) and Aus- tralian (Kangas & Shepherd, 1984) chitons also displayed the species-specific vertical habitat stratification char- acteristic of Caribbean sites. Following hurricanes that struck Turrumote Reef, Puerto Rico, in 1963 and 1967, Glynn (1970) noted 46% and 41% diminutions in numbers of C. tuberculatus and A. granulata. respectiveh', in 1968 — reductions similar to those observed in C. squamosus at Tulum following severe summer storms. Size distributions (table 1) do not elucidate the process of population recovery at Tulum Subsite 7, but suggest migration of adults from other areas less than 3 m distant. As reported previousK- b\ Glynn (1970) for .4. gran- ulata and C. tuberculatus in the eastern Caribbean, A. granulata and C. squamosus from our study area, fed (indexed by movement) primarily nocturnally, and dis- played only weak homing abilities. ACKNOWLEDGEMENTS We thank the following for their assistance in or support of the project: Jose Luis Sierra V. and Eric Villanueva Mukul, Director and Subdirector, Centro Regional del Sureste, Institute Nacional de Antropologia e Historia; Victor Segovia Pinto, Jefe de Campo de la Zona Ar- queologia de Tulum, INAH; and William G. Lyons, Har- old E. and Emilv H. Yokes, Karsten Tedin, Anthony Amos, Chris Kitting, Peter E. Scott, James Ponton, Jeffrey Zeikus, Mark W. Martin, and Nancy G. Lanier Martin. Partial support for this study was provided by the Texas Memorial Museum-The Universitv of Texas at Austin. LITERATURE CITED .•\bbott, R- T, 1974. .American seashells, 2nd ed. Van Nostrand Reinhold, New York, 663 p. Duggins, D, O, and M. N. Dethier. 1985. Experimental studies of herbivor> and algal competition in a low intertidal habitat. Oecologia 67:183-191 Glynn, P. W. 1970. On the ecolog\ of the Caribbean chitons Acanthoplcura granulata Gmelin and Chiton tubercula- tus Linne: density, mortalit\, feeding, reproduction, and growth. Smithsonian Contributions to Zoolog) 66:1-21. Hidalgo, E. 19.56. Algunos moluscos de la Isla de Cozumel, Quintana Roo, Mexico. Acta Zoologica Mexicana 1:1-16. Jaume, M. L. 1946. Moluscos marines litorales del Cabo Ca- toche, Yucatan, Mexico. Revista de la Sociedad Malaco- logica "Carlos de la Torre ' 4:95-110. Kangas. M. and S. A, Shepherd. 1984, Distribution and feed- ing of chitons in a boulder habitat of West Island, South Australia. Journal of the Malacological Society of Australia 6:101-111. Lewis, J. B. 1960. The fauna of rocky shores of Barbados, West Indies. Canadian Journal of Zoology 38:391-435. Otaiza, R. D. and B. Santelices. 1985. Vertical distribution of chitons (MoUusca: Polyplacophora) in the Rocky Intertidal Zone of central Chile Journal of Experimental Marine Biology and Evolution 86:229-240. \okes, H. G, 1983. Distribution of shallow-water marine Mol- lusca, Yucatan Peninsula, Mexico. National Geographic Society Research Reports 15:715-723. Weisbord, N. E. 1926. Notes on marine mollusks from the Yucatan Peninsula, Mexico. The Nautilus 39(3):81-87. THE NAUTILUS 101{2):80-85. 1987 Page 80 Transfer of Cerithiopsis crystallina Dall to the Genus Varicopeza Griindel, Family Cerithiidae (Prosobranchia: Gastropoda) Richard S. Houbrick Department of linertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560, I'SA ABSTRACT The small cerithiid, formerly known as Cerithiopsis crystallina Dall, is transferred from the family Cerithiopsidae to the famih Cerithiidae, genus Varicopeza, on the basis of conchological, radular, and anatomical characters. Varicopeza crystallina is the first Atlantic species of a previously monot\ pic. Indo-Pacific genus. It has an extensive, offshore, geographic distribution throughout the Antilles, Florida, and the Gulf of Mexico. Key uords: Prosobranchia; Cerithiidae; Cerithiopsis; Vari- copeza. systematics; Caribbean. INTRODUCTION Examination of numerous lots of a small enigmatic cer- ithiid-like prosobranch, given the specific name crystal- lina and assigned by Dall (1881:89) with a query to the genus Cerithiopsis Forbes and Hanley, 1851, has prompted this paper. "Cerithiopsis" crystallina Dall, 1881 has been dredged in numerous localities throughout the Antilles, off Florida, and in the Gulf of Mexico. Although common in some museum collections, it is not a well- known species and rarely listed in popular shell books. Dall (1881:89), although initially uncertain of the generic assignment of this species, later (1889:254) allocated it to Cerithiopsis with more certitude, and his allocation has been followed by subsequent authors. Despite Dall's (1881:90) final referral of this species to Cerithiopsis. he appears to have been uncomfortable with this assign- ment, as he compared C. crystallina with other small dredged cerithiids assigned by Watson (1885) to Bittiuni Gray, 1847. Dall apparently examined some live-col- lected material, because he described alcohol-preserved animals as having well developed eyes and long tentacles, and a short rounded foot with a circular operculum. He noted that "the opercular lobe appears to have several short processes on each side". To my knowledge, no other published information about this species exists. A studv of conchological features of "Cerithiopsis" crystallina indicates that this species does not fit the criteria defining Cerithiopsis species. Moreover, recent examination of preserved animals and a study of the radula w ith scanning electron microscopy ha\ e provided substantial evidence that C crystallina should not be considered a member of the Cerithiopsidae. The follow- ing account presents this evidence and provides a new description and generic assignment. MATERIALS AND METHODS Preserved specimens from Spanish Wells, Eleuthera, ob- tained from the gut of the starfish Astropecten, were dissected under a binocular dissecting microscope to study the operculum, radula, and anatomv'. Scanning electron micrographs (SEM) were made of the radula, operculum, and shell on a Zeiss-Novascan-.'30 instrument. The following abbreviations appear in the text: IRCZM, Indian River Coastal Zone Museum, Harbor Branch Oceanographic Institution, Ft. Pierce, Florida; MCZ, Museum of Comparative Zoologv-, Harvard University, Cambridge, Massachusetts; MNHNP, Museum National Figures 1-7. Varicopeza crystallina (Dall). 1. Dead collected specimen from 116 fm, off St. Lucia (USNM 810888), 14.41 mm. 2. Live-collected specimen from 85 fm. Gulf of Mexico, between Mississippi delta and Cedar Keys, Florida (USNM 93763), 17.5 mm. 3. Scanning electron micrograph (SEM) of operculum from specimen off Spanish Wells, Eleuthera, Bahamas (IRCZM 065: 02228), bar = 200 ^m. 4. SEM detail of mid whorl sculpture on specimen from Spanish Wells. Eleuthera, Bahamas (IRCZM 065: 02228), bar = 300 ^m. 5. SEM of protoconch and early whorls of specimen from 100 fm off Barbados (I'SNM 87295), bar = 80 ^m. 6. Closeup of early and midwhorls showing sculptural details on specimen depicted in figure 2 (USNM 93763). 7. Detail of body whorl and aperture from specimen depicted in figure 2 (USNM 93763). R. S. Houbrick, 1987 Page 81 Page 82 THE NAUTILUS, Vol. 101, No. 2 d'Histoire Naturelle, Paris; USBF, United States Bureau of Fisheries; USNM, United States National Museum, National Museum of Natural History, Smithsonian In- stitution, Washington, DC. Records and specimens examined: LESSER AN- TILLES, B.\RB.4.DO.s; MCZ 7406, 13.3 m, R\' Blake, Sta 290; MCZ 7394, 182 m, R\' Hassler, Sta. 1; MCZ 238240 229 m. West Coast, Barbados; USNM 434158, 434164 419146, 419147, 419149, 419150, 434167, 434153, 434154 419148, 430161, 434168, 434159, 434160, 434163, 430162 810910, 810917, all 150-182 m, RV Blake. Sta. 300 Gu.adeloupe: USNM 434155, 1,605 m, RV Blake. Sta 14; St. Lucia: MCZ 7405, 212 m, RV Blake. Sta, 220 USNM 810888, 212 m, RV Blake. Sta. 270, 13°50'15"N 6r03'45"W; Martinique: MCZ 7404, 715 m, RV Blake Sta. 210; Dominica: MCZ 7402, 583 m, Sta. 176; MCZ 7403, 252 m, Sta. 36; St. Croix: MCZ 7399, 7400, 7401, 210-453 m, RV Blake. Sta. 128, 132, 134, all off St. Croi.x. GREATER ANTILLES, Cuba: MCZ 7395, 1,472 m, RV Blake. Sta. 2, off Morro Light, Havana (holotype); MCZ 7398, 823 m, RV Blake. Sta. 51, off Havana; MCZ (no number), 344 m, RV Blake, Sta. 5, off Santiago; MCZ (no number), 457 m, RV Atlantis. Sta. 3490, off Havana i23°ll'N, 81°55'W); USNM 93832, 369 m, RV Blake. Sta. 2131, S of Cuba; USNM 94109, 366 m, RV Blake. Sta. 2135, S of Cuba; Puerto Rico: USNM 161327, Aqadilla. BAHAMAS: USNM 87304, 618 m, RV Blake. Sta. 2655, Little Bahama Bank; USNM 216670, RV Albatross. "Ba- hamas"; IRCZM 065:02228 472 m, RV Johnson. Sta. JSL- 11, 24°52.2'N, 77°15.5'W, off Spanish Wells, Eleuthera; IRCZM 065:00892, 256 m, RV Gerda, Sta. 638, 26°05'N, 79°12'W, Bimini Banks. FLORIDA: USNM 434151, 219 m, RV Eolis, Sta. 330, off Sambo Reef; USNM 516445, 686 m, RV Eolis. Tortugas; USNM 419006, 119 m, RV Eolis. Sta. 100, Sand Kev; USNM 419007, 382 m, Eolis, Sta. 340, off Fowley Light; USNM 419014, 174 m, Eolis, Sta. 325, off Sand Key; USNM 419010, 155 m, Eolis, Sta. 163, off Sand Key; USNM 419012, 165 m, Eolis. Sta. 319, off Western Dry Rocks; USNM 419008, 155 m, Eolis. Sta. 338, off Sand Key; USNM 419009, 155 m, Eolis, Sta. 327, off Sand Key; USNM 434152, 139 m, Eolis, Sta. 161, Sand Key; USNM 419011, 143 m, Eolis. Sta. 63, off Kev West; USNM 419013, 146 m, Eolis. Sta. 320, off Western Dry Rocks. GULF OF MEXICO, USA: USNM 323844, 309 m, USBF Sta. 2400, off Cape San Bias, Florida; USNM 323977, 110 m, USBF Sta. 2402, off Cape San Bias, Flor- ida; USNM 87297, 91 m, RV Blake. W of Florida; USNM 93998, 309 m, USBF Sta. 2400, between Mississippi Delta and Cedar Key, Florida; USNM 608531, 121 m, 100 mi off Ft. Myers, Florida; USNM 83532, Cedar Keys, Flor- ida; USNM 323834, 309 m, USBF Sta. 2400, off Cape San Bias, Florida; USNM 323906, 203 m, USBF, off Cape San Bias, Florida; USNM 93763, 161 m, US Fish Com- mission Sta. 2403, between Mississippi Delta and Cedar Keys, Florida; MNHNP, 344-346 m, 28°19'N, 85°44'W; MCZ I458I9, 24-35 m, 1,5-35 mi off Ft W^alton, Florida; Mexico: USNM 667771, 168 m, Sta. 1253, Campeche Banks, off Yucatan. RESULTS Description: Shell small, reaching 19 mm in length and 4 mm in width [length measurements of random sample from throughout geographic range: x = 14.64; sd = 2.49; range = 10.81-18.04 (n = 13)]. Shell translucent white, turreted, elongated, comprising up to 25 straight-sided whorls (figures 1, 2). Shell sculptured with 3 major, nod- ulose, spiral cords and 14 axial ribs per whorl (figure 4). Suture deeply impressed. Protoconch-one not seen; pro- toconch-two large, comprising about 3 whorls (figure 5). Protoconch-two lacking sculpture except for spiral row of minute pustules adjacent to suture and 2 very weak, spiral cords (figure 5). Pronounced sinusigeral notch pres- ent. Four to 6 juvenile whorls beneath protoconch sculp- tured with axial ribs only (figure 5). Subsequent early whorls with 2 beaded spiral cords per whorl that become 3 major spiral cords in later whorls (figure 6). Of these 3, first spiral cord adapical, other 2 cords separated by weaker, less nodulose spiral cord (figure 4). Bod\ whorl constricted at siphonal canal and sculptured with 4 raised, nodulose, spiral cords and 5 or 6 smooth cords on base (figure 7). Outer lip convex and slightly pinched into posterior anal notch where it joins penultimate uhorl. Aperture ovate with wide, distinct anterior canal and well-developed anal canal (figure 7). Operculum thin, corneous, circular, externally con- cave, and with central nucleus; early whorls multispiral, becoming paucispiral later (figure 3). Animal with short, wide, bilobed snout and pair of very long cephalic tentacles. Cephalic eyes large, black. Mantle edge wavy, edged with tiny papillae strongly developed at inhalant siphon. Buccal mass relatively large, bearing small pair of jaws and short taenioglossate radula. Radula (figure 8) with about 18 rows of teeth. Rachid- ian tooth (figure 10) with hourglass-shaped basal plate and cutting edge of 1 large central cusp flanked on each side by 3 small denticles. Lateral tooth (figures 9, 10) wide, rhomboidal, with long lateral extension, and cut- ting edge comprising one sharp, tiny, inner denticle, a large pointed cusp and 4 or 5 sharp, outer denticles. Marginal teeth (figure 9) long, hook-like, with sharp tips comprising central cusp and 3 sharp, inner denticles. Inner marginal tooth with 2 small denticles on outer side; outer marginal with smooth outer edge. Discussion: Although many authors have placed "Cer- ithiopsis" crystallina in the Cerithiopsidae, this classi- fication has not realK been satisfactor\ . Cerithiopsids are characterized b\' small turreted shells having well-de- veloped, beaded, spiral sculpture, an aperture with a slight to Daring anterior notch, and a flattened, excavated shell base. The\' have a pleurembolic proboscis and a distinctive radula (Marshall, 1978:59-60, figs. 3, 4). The shell of "Cerithiopsis ' crystallina is not really comparable with those of cerithiopsid species. The sculp- ture is more nodular than beaded and more strongly spiral in composition. The base of the shell is not flattened or excavated and has a longer, wider anterior canal than those of cerithopsid species; moreover, the aperture has R. S. Houbrick, 1987 Page 83 a distinct anal canal and the upper lip flares into a weak notch where it joins the penultimate whorl. The short, wide snout does not have the pleurembolic proboscis of Cerithiopsis species. The tiny taenioglossate radula of C. crystallina is close to those of members of the Cerithiidae in overall morpholog\' (see Houbrick, 1978, 1980, 1985). Dall (1889:254) noted the long cephalic tentacles and large, black e\ es. His description of the external features of the animal agrees with m\- observations, but I did not find the "opercular lobe with "several short processes on each side", which he mentioned. Dall s words seem to indicate epipodial tentacles, such as found on Litiopa Rang and Alaba H. and A. Adams species, but I found no trace of these structures. The material I examined appeared to be in good condition; consequentK', I cannot explain this discrepancy. The soft anatom\ , radula, and shell of "Cerithiopsis" crystallina indicate that this species should be removed from the Cerithiopsidae, superfamily Cerithiopsacea, and transferred to the Cerithiidae, superfamily Cerithiacea. Cerithiopsids, although traditionalK- grouped with the cerithiids on the basis of shell morpholog\ , are now con- sidered as a separate superfamiK (Kosuge, 1966; Mar- shall, 1978, 1983). They have been placed in the super- order Heterogastropoda by Kosuge (1966:297) and more recently in a new suborder, Heteroglossa, by Haszprunar (1985). Further evidence separating cerithiopsids from cerithiaceans has been presented by Healy (1983:212, 1986:195) who has discovered that their euspermatozoan morphology is quite different from that of other ceri- thiaceans. Comparison of the shell and radula of Cerithiopsis crystallina with those of other small-shelled taxa within the Cerithiidae shows that it most closely resembles those of species in the genera Bittium Gra\, Argyropeza Mel- vill and Standen, and Varicopeza Griindel. Of these three taxa, the shell shape and sculpture typical of Bittium species (Houbrick, 1977) does not closely match the over- all morphology' of C. crystallina. although there is some resemblance. Protoconch-two of Argyropeza species, as depicted by Houbrick (1979:8, fig. 2), is different from that of C. crystallina, as is the sculpture of the adult whorls and the aperture. Thus, Bittium and Argyropeza are best excluded as proper generic assignments. Shell characters such as the strong, nodulose spiral sculpture, deepK impressed suture, and aperture with a well-de- fined anal canal and posterior apertural notch all indicate a morphological resemblance to Varicopeza. a monotyp- ic taxon previously known only from the Indo-Pacific and represented bv V. pauxilla (A. Adams, 1854) (see Houbrick, 1980:528-529, figs. 1, 2). The radula of C. Figures 8-10. Radula of Varicopeza crystallina (Dall) from Spanish Wells, Eieuthera, Bahamas (IRCZM 065:02228), 8. General view of raduiar ribbon, bar = 43 iim. 9. Detail of half row of teeth, bar = 25 ^m. 10. Detail of rachidian and lateral teeth, bar = 10 ^m Page 84 THE NAUTILUS, Vol. 101, No. 2 Figure 11. Geographic distribution ol Varicopeza crystallina (Dall) based on collection data. crystallina, particularly the hourglass-shaped rachidian tooth and the dentition and overall shape of the other teeth, is also similar to that of Varicopeza pauxilla. The shell of Varicopeza pauxilla is not as large or elongate as that of C crystallina and has a more strongly defined posterior apertural notch. The operculum of the two species differs, that of V. pauxilla has a more eccentric nucleus and is more ovate than the operculum of V. crystallina. It appears that C. crystallina most closely resemf)les Varicopeza, and as I consider the concholog- ical and opercular differences between the two taxa noted above to be specific ones, proposal of a new genus to accommodate C. crystallina is not justified. I think it best to assign this Western Atlantic species to the genus Var- icopeza. The genus Varicopeza was previously know n only from a single Indo-Pacific species. The addition of V. crys- tallina to the genus adds a Western Atlantic component to the geographical distribution of this group. Varicopeza crystallina has a wide geographic distribution through- out the Lesser and Greater .Antilles, the eastern Gulf of Mexico, and around the Florida peninsula (figure 11). Collection data indicate that it is a common offshore species having a wide batlnmetric distribution ranging from 14.8 m to 1,605 m, with a mean depth of 272 m (n = 41). Nearly all lots comprised a great number of specimens. The deepest collected specimens are from the Lesser Antilles, while those from shallowest areas are from off the west coast of Florida. .\11 specimens have come from sandy, silty bottoms and although man\ rec- ords are for empty shells, there were enough live-col- lected lots (dried animals in shells) to dismiss the possi- bility that this species occurs in significantK different bathymetric ranges than indicated. .Specimens (empty shells) have been found on the beach at Cedar Keys, Florida, R. S. Hoiibrick, 1987 Page 85 CONCLUSIONS Synonymy: The following syiioiiyniy summarizes tiie taxonomic decisions reached in this paper. A more com- plete definition of the genus Varicopcza is found in Houbrick (1980:525-526). FamiK Cerilhiidae Fleming, 1822 Genus Varicopcza Griindel, 1976 Varicopcza crijstallina (Dall, 1881) Cerithiopsis ? crystallimi Dall, 1881:89. Holotype: MCZ 7395, figured type and one paratype; type-locality: RV Blake. Sta. 2, off Morro Light, N of Havana, Cuba — also Bar- bados: here restricted to off Morro Light, N of Havana, Cuba; 1889:254, pi. 20, fig. 3. Cerithiopsis crystallinum Dall, .-Abbott, 1974:109, fig. 1049G; Dall and Simpson, 1901424; Warmke and Abbott, 1962: 75; Rice and Kornicker, 1965:119, pi. 2, fig. 9; Boss et al, 1968:95. ACKNOWLEDGEMENTS This is contribution No. 181 of the Smithsonian Marine Station at Link Port, Ft. Pierce, Florida, where most of this work was done, I thank Paula Mikkelsen, assistant curator, Indian River Coastal Zone Museum, Harbor Branch Oceanographic Institution, Ft. Pierce, Florida, for the loan of preserved specimens in her charge, Drs. Rudiger Bieler and M. G. Harasewych of the Smithsonian Institution critically read drafts of the manuscript. I thank Dr. Kenneth J. Boss, Museum of Comparative Zoology, Cambridge, Massachusetts, for sending data about t>pe- material, 1 also thank Julianne Piraino for assistance on the SEM. LITERATURE CITED Abbott, R. T. 1974. American seashells, 2nd ed. New York, 663 p., 24 pis., 6405 figs. Adams, A. 1854. A monograph of Cerithidea. a genus of Mollusca, with descriptions of several new species, from the collection of Hugh Cuming, Esq.: to which are added descriptions of two new species of Colina. and one of Donax. Proceedings of the Zoological Society of London 22:83-87. Boss, K. J., J. Rosewater, and F. A. Ruhoff. 1968. The zoo- logical ta.xa of William Healy Dall Bulletin of the U.S. National Museum No, 287:427 p. Dall, W. H 1881. Reports on the results of dredging, under the supervision of Alexander Agassiz, in the Gulf of Mexico and in the Caribbean Sea, 1877-1879, by the L'S. Coast Steamer "Blake . Preliminary report on the Mollusca. Bul- letin of the Museum of Comparative Zoologv, Harvard 9: 33-144, Dall, W. H. 1889. Reports of the results of dredging, under the supervision of .Alexander Agassiz, in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80), by the U.S. Coast Survey Steamer "Blake Lieut -Commander C. D. Sigsbee, U.S.N. , and Commander J. R. Bartlett, U.S.N., commanding Report on the Mollusca. Part 2. Gastropoda and Scaphopoda. Bulletin of the Museum of Comparative Zoology, Harvard 18:1-492, pis. 10-40. Dall, W. H.' and C. T. Simpson. 1901. The Mollusca of Porto Rico. Bulletin of US, Fish Commission for 1900 1.351- 524, pis. 53-58. Fleming, J. 1822, The philosophy of zoology or a general view of the structures, functions, and classifications of an- imals, etc., 2 vols Edinburgh, no pagination Forbes, E. and S, Hanley, 1850-51. .\ history of British Mol- lusca and their shells. Vol. 3. Van Voorst, London, 616 p Gray, J. E. 1847. The classification of the British Mollusca by N. E. Leach, M.D. Annals and Magazine of Natural His- tory 20:267-273. Griindel, J. 1976, Zur Taxonomie und Phylogenie der BH- tium-Grnppt- (Gastropoda. Cerithiacea). Malakologische Abhandlungen Staatliches Museum f iir Tierkunde in Dres- den 5(3):33-59, 2 pis., 17 figs. Haszprunar, G. 1985. The Heterobranchia — a new concept of the phylogen)' of the higher Gastropoda. Zeitschrift fiir Zoologische Systematik und Evolutionstorschung 23(1):15- 37. Healy, J. M. 1983. llltrastructure of euspermatozoa of ceri- thiacean gastropods (Prosobranchia: Mesogastropoda). Journal of Morphology 178:57-75. Healy, J. M, 1986. Ultrastructure of paraspermatozoa of cer- ithiacean gastropods (Prosobranchia: Mesogastropoda). Helgolander Meeresuntersuchungen 40:177-199. Houbrick, R. S. 1977. Reevaluation and new description of the genus Bittium (Cerithiidae). The Veliger 20(2): 101- 106. Houbrick, R. S. 1978, The family Cerithiidae in the Indo- Pacific, Part 1: the Genera Rhinoclavis, Pseudovertagus. Longicerithium, and Clavocerithium. Monographs of Ma- rine Mollusca No. 1:130 p., 98 pis. Houbrick, R. S. 1979. Review of the deep sea genus Argy- ropeza (Gastropoda: Prosobranchia: Cerithiidae). Smith- sonian Contributions to Zoology No. 321:.30 p., 12 pis. Houbrick, R, S, 1980. Reappraisal of the gastropod genus Varicopeza Griindel (Cerithiidae: Prosobranchia). Pro- ceedings of the Biological Society of Washington 93(3): 525-535. Houbrick, R, S. 1985. Monograph of the genus Clypeornonis (Cerithiidae, Prosobranchia). Smithsonian Contributions to Zoology No. 403:131 p., 62 pis Kosuge, S, 1966. The family Triphoridae and its systematic position. Malacologia 4(2):297-.324. Marshall, B. A. 1978. Cerithiopsidae (Mollusca: Gastropoda) of New Zealand and a provisional classification of the family. New Zealand Journal of Zoology 5:47-120. Marshall, B. A 1983. A revision of the Recent Triphoridae of southern Australia, Records of the .Australian Museum, Supplement 2:119 p., 33 figs. Rice, W. H. and L, Kornicker. 1965, Mollusks from the deeper waters of the northwestern Campeche Bank, Mexico, Pub- lications of the Institute of Marine Science, Texas 10:108- 172. Warmke, G and R T .A.bbott 1961 Caribbean seashells. Narberth, PA, 346 p , 44 pis. Watson, R. B. 1884-86. Report on the Scaphopoda and Gas- teropoda collected by H.M.S. Challenger during the years 1873-1876. In: Report on the scientific results of the voy- age of the H.MS. Challenger during the years 1873-76 15(42):756 p., 53 pis. THE NAUTILUS 101(2):86-87, 1987 Page 86 Identity and Status of Philomycus pennsylvanicus Pilsbry, 1894 (Gastropoda: Pulmonata: Philomycidae) H. Lee Fairbanks The Penns\l\aiiia State University Beaver Campus Monaca, PA 15061, USA ABSTRACT The nomenclatural history of Plulornycus pennsylvanicus Pils- bry, 1894 is resiewed. As the original specimens were lost and their description was incomplete, two field trips were conducted to locate the population from which the specimens were col- lected. The results of this fieldwork and a study of the Inter- national Code of Zoological Nomenclature support two con- clusions: (1) Philomijcus pennsylva7iicus is a nomen nudum and (2) the slug that Pilsbry began to describe is probably what is now known as Megapallifera mutabilis (Hubricht, 1951), INTRODUCTION The name Philomycus pennsylvanicus was cited by Pils- bry (1894) for "A maculated species . . .", an extremely cryptic description. A "Full description ..." was to be published at a later date. Subsequent usage in fauna! lists or descriptive papers was limited to Sterki (1907), Dai! (1916), and Clapp (1920). In his monograph of North American land mollusks, Pilsbry (1948:767) transferred the name to the genus Pallifera, and explained the lack of the promised detailed description, because of "... a local flood ..." which destroyed the specimens. Pilsbry (1948) also noted that "It is practically a nude name." The original collection by Witmer Stone was from York Furnace, York County, Pennsylvania. Fieldwork to resample this population and lab work to determine its identity are reported below. MATERIALS AND METHODS Two field trips were conducted to the town of York Furnace, York County, Pennsylvania (ca. 76°23'18"W, 39°52'25"N) (figure 1 ), the locality given by Pilsbry (1894). Specimens were collected from trees, logs, under loose bark, and in the litter around the bases of trees. Data collected included length (live specimens), mantle pat- tern, and the appearance of the jaw and reproductive system. Dissected specimens were drowned first in dis- tilled \s ater. All material was preserved in 70% ethanol. RESULTS A total of 22 slugs were collected on May 22, 1984, after a rainy night. Dissection revealed that all but one of these specimens were attributable to the genus Philo- mycus (presence of dart sac and dart). The reproductive system of the one specimen was not fully developed, but the slug did have a ribbed jav\' and was therefore iden- tified as a species of Pallifera. An additional 36 slugs were found on July 18, 1984, also after a night of rain. The mantle pattern on five of these slugs was different from that of the others. Dissec- tion demonstrated that all five lacked a dart sac and dart; the other 31 were all species of Philomycus (dart and dart sac present). One of the five specimens measured 30 mm in length (crawling), the others were larger (four specimens, average length crawling 51 mm, range 45- 55 mm). All specimens were mature, i.e.. had fully de- veloped reproductive systems. Voucher material, three specimens of Philon}ycus car- olinianus and one specimen of Pallijcra mutabilis has been deposited in the United States National Museum (USNM 853181 and 853182). DISCUSSION The International Code of Zoological Nomenclature (1985) Chapter IV, Article 12 states, "To be available every new scientific name published before 1931 must satisf\ the provisions of Article 1 1 and must be accom- panied by a description or a definition, of the taxon that it denotes, or by an indication." In addition. Article 10(b) states, "If publication of the data relating to a new nom- inal taxon or a nomenclatural act is interrupted and con- tinued at a later date, the name or nomenclatural act becomes available only when it satisfies all the relevant provisions of Articles 10 to 20." Pilsbry stated (1894) that he would publish a "Full description with anatomical details ... at a later date. ClearK, publication was in- terrupted because he intended to publish at a later date, data ". . . relating to a new nominal taxon . . .". Because the name did not become available, Pilsbry created a H. L. Fairbanks, 1987 Page 87 A y*^ £k York Furnace Figure 1. A. The location of York Furnace in York County, Pennsylvania. B. The Y'ork Furnace area, the cross-hatching represents the search area. Scale bar equals 0.5 km. nomen niiJiim which has no standing in zoological no- menclature. Comparison of the dart-less slugs collected at York Furnace during this study with the descriptions of the species of Pallifera and Megapallifcra resulted in the following identifications. The larger specimens were M. mutabilis (Hubricht, 1951) (confirmed by L. Hubricht, personal communication, August 31, 1984); the smaller specimen was Pallifera josteri Baker, 1939. Pilsbry (1894) described Plulomycus pennsylvanicus as "A maculated species having the jaw strongly ribbed. It is smaller and less distinctly marked than P. cawli- nianus" (length crawling 70-100 mm). Pilsbry was fa- miliar with Pallifera dorsalis, then called Philomycus dorsalis (length crawling 20-25 mm). If P. pennsylvan- icus was small, i.e.. 30 mm long, it would seem likely that Pilsbry would have compared it to Pallifera dorsalis. Smaller than Philomycus carolinianus then probably meant closer to 70 mm long rather than 25 mm, i.e., closer to the size of Megapallifcra mutabilis (length craw ling ca. 50 mm), not Pallifera fosteri (length crawl- ing ca. 30 mm). The results of this study support two conclusions. One, Philomycus pennsylvanicus is a nomen nudum and therefore must be dropped from the literature and should not appear in any future synonymy. Two, it appears likely that the slug Pilsbry described was what is now known as Megapatlifera mutabilis (Hubricht, 1951). ACKNOWLEDGEMENTS The author thanks Leslie Hubricht for his confirmation of the identification of specimens, and Walter B. Miller, Richard L. Reeder, and Russell Doyle for their encour- agement and critiques of the first draft of this paper. Financial support was granted by the Faculty Scholar- ship Support Fund of The Pennsylvania State University. LITERATURE CITED Baker, F. C 1939, Fieldbook of Illinois land snails. Illinois Natural History Survey Manual 2:133-134, Urbana, Illi- nois, Clapp, W. F. 1920. The shell of Philomycus carolinianus (Bosc). The Nautilus 33(3);8:3-S9, Dall. W. H, 1916. Shells of Mt. Monadnock, N.H, The Nau- tilus 30:57-58. Hubricht, L. 1951. Three new land snails from eastern L'nited States. The Nautilus 65(2):57-59. International Commission of Zoological Nomenclature. 1985. International Code of Zoological Nomenclature, 3rd ed. London, 338 p. Pilsbry, H. A, 1894. Critical list of mollusks collected in the Potomac Valle\', Proceedings of the .\cademy of Natural Sciences of Philadelphia for 1894:11-31, Pilsbrv, H, .\ 1948. Land Mollusca of North America (north of Mexico). Academy of Natural Sciences of Philadelphia Monographs No. 3, Vol. II, Part 2. Sterki, V, 1907. A preliminary catalogue of the land and fresh- water Mollusca of Ohio, Proceedings of the Ohio State Academy of Sciences \'ol, I\', Part 8, Special Papers No. 12:367-402. THE NAUTILUS 101(2):88-92, 1987 Page The Diet and Feeding Behavior of Cadulus tolmiei Dall, 1897 (Scaphopoda: Siphonodentahoida) Perry A. Poon 167 Millbourne Road East Edmonton, Alberta T6K 1R2 Canada ABSTRACT Specimens of Cachihis tolmiei and sediment samples were ob- tained from Numukamis Bay, Barkley Sound, off Vancouver Island, British Columbia. The shell length and oral aperture diameter were measured, and the scaphopods dissected to re- move gut contents. Live and dead prey items were recorded, and foraminiferans identified to genera. Sediment samples were analyzed for potential prey. Chi square tests showed significant differences between the relative abundances of organisms in the buccal pouches and the sediment, and between the relative abundances of live and dead organisms within the buccal pouches. Selective indices show C. tolmiei to feed preferentially on living foraminiferans, particularly Uvigerina sp. The feed- ing behavior of this cadulid is similar to that of dentalioid scaphopods. INTRODUCTION The class Scaphopoda is a very uniform group within Mollusca, characterized by specialized habits and sim- plified structures (Morton & Yonge, 1964). Scaphopods are detritivores and micro-carnivores, living in the sand with their shell apices above the substrate (Morton, 1967). The shell is usually oriented with its concave side upward (figure 1). Palmer (1974) divided the Scaphopoda into the orders Dentalioida and Siphonodentalioida, which can be dis- tinguished on the basis of e.xternal features. The Den- talioida have elongated conical shells and a conical foot. The Siphonodentalioida have a vermiform loot with a crenulated pedal disc, and are generally smaller than dentalioids (Pelseneer, 1906; Palmer, 1974). Scaphopods burrow and construct a feeding cavity wherein the captacula probe the cavity walls (Gainey, 1973) and substrate, and detect and capture live fora- miniferans and other prey (Morton, 1959; Gainey, 1973; Bilyard, 1974). Dentalioid epipodial lobes may dislodge and waft .sediment toward the oral aperture, where the captacula probe it (Dinamani, 1963). When food is ab- sent, scaphopods burrow to a new location (Gainey, 1973). Dinamani (1963) observed Dentalium conspicuum Melvill collecting and conveying particles along its cap- tacula by ciliary action. These particles were whisked onto the captaculum by the cilia on the bulbous tip and transported along the filament to the mouth by ciliary action. Morton (1959) suggested that D. entalis Linne may use captacular alveoli as suction cups to capture foraminiferans. Gainev (1973) observed D. cboreum Conrad and D. pseudohexagonum Henderson probing into the substrate with their feet to form feeding cavities (figure L fc). The captacula then browsed along the cavity walls and conveyed small particles to the mouth. BiKard (1974) showed that D. cntalc stirnpsot}! Hen- derson feeds selectively on living foraminiferans and or- ganic material, and rejects dead foraminiferans and in- organic material. There have been few studies on siphonodentalioids. Davis (1968) described the captac- ular behavior of Cadiihis qiiadridentatus Dall, but did not observe feeding. Rokop (1977) reported a seasonal reproductive cycle in C. californicus Pilsbry and Sharp. CMduliis tolmiei is a common deepwater siphonoden- talioid occurring in Barkley Sound, off the western coast of Vancouver Island, British Columbia. The feeding be- havior of this species is described and compared to that of dentalioid scaphopods. The diet of Cadulus tolmiei and the selection of particular prey items are reported. MATERIALS AND METHODS Specimens of Cadulus tolmiei were dredged from two sites in Numukamis Ba\ on June 22, 1984. Site 1 (4S°53.70'N, 125°00.83'W to 48°54.01'N, 125°02.98'W, in 139-199 m) yielded 26 specimens; site 2 (48°53.80'N, 125°03.12'W to 48°53.77'N, 125°03.84'W, in 157-183 m) yielded 61 specimens (voucher specimens USNM 859073). A thermometer was inserted into the samples immedi- atel) upon collection to determine the bottom sediment temperature. Temperatures at site 2 averaged 8.9 ± 0.4 °C. No sediment was obtained at site 1. Twenty-four specimens from site 1 and 11 specimens from site 2 were preserved in 37"^^ isopropyl alcohol containing Rose Bengal. Shell lengths and oral aperture widths were measured, and the specimens dissected. All prev items were removed from the buccal pouches, live (stained) and dead (unstained) prey items recorded, and p. A. Poon, 1987 Page 89 — cb ^5f^'.;vY i'Vm^-PxC-^- Figure 1. Cadulus folmici in sediment, showing orientation, cb, captacular burrow, del, digestive diverticula; fc, feeding cavity, g, gonad; m, mantle; pa, posterior appendix; s, shell. prey maximum lengths measured. Foraminiferans were identified to genus using the keys in Cushman (1959). Sediment samples were immediately preserved in Rose Bengal-isopropanol solution, sieved to 63 /jm and ex- amined under a dissecting microscope. All stained po- tential prey items were counted and collected. A linear regression (Schefler, 1969) of C. tolmiei oral aperture width vs. live prey item length was plotted and the correlation coefficient calculated. Chi scjuare tests (Siegel, 1956) were used to determine if there were sig- nificant differences between the prey items in the buccal pouches and in the sediment, and between the live and dead prey items in the buccal pouches. Selective indices (Bilyard, 1974), the ratios of percent organisms in the buccal pouches to the percent organisms in the sediment, were calculated for the major prey categories. Indices greater than 1.0 indicate positive selectivity, values less than 1.0 indicate negative selectivitv (BiKard, 1974). Additional sediment was sieved through a 1 mm screen to remove macro-invertebrates, and kept in plastic, mesh- sided containers in circulating seawater (9.6 ± 0.2 °C). These samples were further sieved through 275 nm. 180 ixm. and 63 nm screens to retrieve foraminiferans for use as prey in feeding observations. Living Cadulus tolmiei were attached to glass slides with rubber bands and placed Figure 2. Observation tank constructed from 2 x 8 cm glass slides. Scaphopod is attached to slide by rubber band. about 1 mm above the substrate in a small glass tank filled with sediment and seawater (figure 2). Tempera- ture was maintained at 13.2 ± 0.8 °C. Specimens were backlit to reveal internal activity through the translucent shell. Foraminiferans were placed in the tanks and feed- ing observed through a horizontally mounted dissecting microscope. RESULTS Living and dead organisms taken from the buccal pouch- es of Cadulus tolmiei were identified, counted, and are listed in table 1. The site 2 sediment sample was com- posed mostly of silty fecal pellets. Nematodes, annelids and dead centric diatoms were common. The forami- niferans Bu/iHiina sp., Vvigerina sp., Bolivina sp., Quin- queloculina sp., and Rheophax sp. were present in the Page 90 THE NAUTILUS, Vol. 101, No. 2 Table 1. Buccal pouch contents of 26 Cadulus lolmiei. Table 3. Chi square test comparing live prey in sediment and Number Total Number in Number in buccal Live prey items Dead Live Foraminifera Bulimina sp. 29 2 18 24 47 26 Live prey items sediment pouches Total Vvigerina sp. Bulimina sp. 33 51 84 Bolivina sp. 5 1 6 Vvigerina sp. 4 33 37 Truncatulina sp. 4 2 6 Eggs 39 34 73 Discorlns sp. 1 2 3 Others 14 36 50 Clobigcrina sp. S'onionella sp. 1 I 2 0 3 Total 90 154 244 Unidentified foraminiferan 1 0 X'ta - o(irii idii = 16.2 ( Foraminiferan fragments 6 1 X^.,in,i.„„i = 20.75 Uvigerina sp. fragments 3 4 Bulimina sp. fragments 2 2 Mollusca Juvenile Table 4. Chi square test the buccal pouches comparing dead and live prey within Bivalves 1 1 2 Eggs Number Number Thick shelled eggs 2 27 29 Prey items dead live Total Thin shelled eggs Egg shell 3 1 4 Bulimina sp. Vvigerina sp. 1 0 1 31 5 20 28 51 33 Inorganic material Eggs 6 28 34 Detritus 6 0 6 Others 26 10 36 Other Total 68 86 154 Unidentified X-,„.u«ii.i,ii = 16.27 Test 0 1 1 X%.,c„l.,e collection; Museo Poey. fide Jaume & Sarasiia, 1943; ANSP 316919); Camarioca Reef area, Matanzas (J. Finlay, leg.); Bahia de Matanzas (R. Burquete, leg.). A live-collected, mature, female snail was collected May, 1986 by Joseph Lleida at Brown s Point, New Prov- idence, Bahamas, where it was found living in shallow water. The specimen, which had a shell 32.1 mm long and 11 mm wide, was preserved in 70% EtOH. It was kindly given to one of us, R Tucker .Abbott, and sent to the senior author for anatomical studies. The soft parts were extracted by breaking the shell in a small vise. The animal was dissected under a binocular dissecting mi- croscope. Shell pieces, apex, operculum, and radula were examined using a Zeiss Novascan-30 scanning electron microscope. This specimen and its parts (USNM 859097) are deposited in the National Museum of Natural His- tory, Smithsonian Institution. RESULTS Systematic Description Family Cerithiidae Fleming, 1822 Subfamil)- Cerithiinae Fleming, 1822 Genus Fastigiella Reeve, 1848 Genus Fastigiella Reeve, 1848:14-1.5. Type-species. Fastigiella carinata Reeve, 1848, b> monot\py. Diagnosis: Shell large, turreted, high spired, sculptured with 3 major, strong, raised spiral cords per whorl, ex- clusive of body whorl. Aperture ovate, about Vi the shell length, and with short, recurved anterior canal. Pseud- umbilicus and siphonal fasciole present on mature adults. Taenioglossate radula with lateral teeth having large bas- al plate and long lateral extension; marginal teeth long, hook-like. Paired salivary glands in front of nerve ring. Hypobranchial gland comprised of man\- transverse leaf- lets. Strong longitudinal ridge bisects distal oviductal groove of pallial oviduct. Remarks: Various fossil species have been referred to Fastigiella (e.g., by Cossmann, 1906:93-95). The only one appearing to us as possibly belonging in the genus is "Cerithium" rugosiitn Lamarck. 1804. of the Middle Eocene of France. Mellciillia C^ossmann. 1889. named as a Lower Eocene "section of Fastigiella from France, has none of the characteristics of the genus. The Eocene fossil. Zefallacia australis (Suter, 1919) somewhat resem- bles Fastigiella. Fastigiella is a nionotx pic geims restricted to a small area of the western Atlantic, i.e., the central Bahamas and northwestern Cuba. Its closest relatives appear to be in the cerithiid genus Pscudovcrtagus \ignal, which is now confined to the Indo- Pacific. "Fastigiella" squamii- losa Pease. 1868. from the Tuamotus (.Polynesia), is a high-spired Recent Coralliophita species. Figures 1-5. Fastigiella carinata Reeve from Holms Cay. Berry Islands, Bahamas. Note light tan spiral band adjacent to suture. Leiinth 44.4 mm (J. Cord\ collection). L ,\perliiral view showing anal fasciole and pseudumbilicus, 2. Lateral view, showing coiiBgnration of outer lip. '.\. Basal \iew. showing reflected anterior canal and basal sculpture. 4. Dorsal view. 5. Dorsal view of shell « hitencd w ith ammonium chloride to enhance sculplnral details. Figures 6-8. FasligicUa carinata. juvenile from Nassau, New Providence Id. Bahamas Length 12 mm (J Lieida collection). 6. Scanning electron micrograph of earl\ whorl scnipture of specimen in figure 8 (protoconch missing). 7. Detail of midw horl sculpture of shell in figure 8. 9. Upper whorls of Pscudovcrtagus aluco Vignal, showing early sculpture similar to that of adult Fastigiella. Total shell length 79 mm. Figures 10. 11. Scanning electron micrographs showing microscopic spiral striae (fragments of USNM 859097). 10. Scale bar = 200 nm. 11. Close up of spiral striae showing microscopic cancellate sculpture of striae. Photograph turned 90 degrees; scale bar = 600 iim. R. S. Houbrick et al.. 1987 Page 103 Page 104 THE NAUTILUS, Vol. 101, No. 3 Fastigiella carinata Reeve Fastigiella carinata Reeve, 1848:15, 1 fig. Type-locaUty un- known; subsequently selected: Eleuthera, Bahamas (Sara- sua and Espino.sa, 1977:4); two s\ ntvpes: BM(NH) 1986272; 1860:122-123, Woodward, 1851:129; H. .'\dams and A. Adams, 1853:155,655, pi. 16, fig. 7; Clienu, 1859:182, fig. 916; Trvon, 1882:249, pi. 70, fig. 64; pi. 10, fig. 46; Thiele, 1929:214; VVenz, 1943:770, fig. 2230; Pilsbrv, 1953:77-78, pi. 6, figs. 2, 3; Kline, 1953:142; Jensen, 1968:6-7, fig.; Abbott, 1974:105, fig. 1009; Sarasua and Espinosa, 1977: 1-11, fig. 1; Abbott and Dance, 1982:68. fig. 6. Fastigiella poiilseni Morcli, 1877:207-208. (Type-locality: Eleuthera, Bahamas; holotype: an immature shell without a pseudumbilicus.) Poulsen, 1878:9, no. 533; Perez Far- farite, 1940:71, pi. 13, fig. 3; Jaume and Sarasiia, 1943:57. Fastigiella (Cerithidea) carinata Reeve. Ford, 1945:8. Description: Shell description (figures 1-8, 10, 11): Shell length 11.2-48.4 mm [mean 33.0 inm; n = 16; observed up to 53.2 mm in Cuba (Sarasua & Espinosa, 1977:5, 11)]. Spire high; spire angle 25-35 degrees (mean 28 degrees). Shell fairly thin to thick, white, sometimes with brov\ nish orange or light tan spiral band (figures 1, 2, 4). Periostraeum inconspicuous, but scale-like when viewed microscopically (figures 10, 11). Protoconch unavailable (shell prone to decollation). Teleoconch whorls 11. 7 + . Teleoconch initially with a subsutural ramp and 3 spiral cords, the uppermost forming a slight shoulder (figures 6, 7). Upper whorl cords with slight nodes or prickles caused by weak, regularly spaced axial growth wrinkles. Lower whorls of large shells with increasing number of spiral cords (figures 1-5), the new ones beginning as intercalations. Subsutural ramp becoming a wide, slightly raised cord accompanied below by a smaller cord. All other cords larger and about equal-sized on large shells. Counting all 3 kinds of cords, there are 11-14 on last whorl of large shells. Fine spiral threads on all cords and interspaces (figure 10). Pair of subperipheral keels absent on small shells. Suture slightly impressed. Several irreg- ularly spaced faint varices present on lower whorls of large shells (figure 3). A short, somewhat recurved but deeply incised anterior canal present (figures 1, 3, 8). On small shells its left edge is a slightly raised spiral fold joining the columella distalK ; on large shells a faint swell- ing in its place (figure 1). Anterior canal \ariable in width (averaging lairly wide) and, after shell attains length of about 25 mm, leaving a spiral siphonal fasciole with strong growth lines (figure 3). A pseudumbilicus (figure 1) of variable width (up to 1.3 mm) and morphology develops after shell reaches length of about 25-35 mm. Parietal callus thin, conforming with underlying cords on small shells; on large shells callus thick and not con- forming, so that there can be 1-3 false umbilical chinks formed by cord interspaces to produce a siphonal fas- ciole. Faint, v\'ide posterior canal present on large shells, viewed aperturalK (figure 1). Columella roimdK con- cave. Outer lip thin in juveniles and thick on large shells; no thick peritreme callus, eversion of outer lip, or up- turned suture near outer lip. External anatomy (figure 18): Adult female (shell 32 mm long) body slender, tapering, and comprising 6 or 7 whorls. Animal whitish with tiny red dots on head- foot. Head has conspicuously large, broad, spade-shaped snout, bilobed at the tip (figure 18, sn). Pair of stubby cephalic tentacles and tiny black eye at peduncular base of each tentacle (figure 18, t). Foot thick and muscular. Propodial mucus gland (figure 18, mg) is a deep slit along leading edge of anterior sole. Sole composed of thick, hard, yellowish tissue thrown into lumps. Large, dark brown, horny operculum (figure 17) thick, ovate, pau- cispiral with subcentral nucleus and filling the shell ap- erture. Columellar muscle (figure 18, cm) thick and short, about '/2 mantle cavity length. Mantle edge thick and dorsally fringed with short papillae (figure 18, mp). In- halant and exhalant siphons inconspicuous except for slight thickening of mantle edge. Posterior 5 whorls com- prise digestive gland (figure 18, dg), which is overlain by ovarv (figure 18, ov). The 2 whorls above body whorl accommodate the kidney (figure 18, k) and stomach (fig- ure 18, st), respectively. Mantle cavity: Mantle cavity deep and spacious, oc- cupving about 2.5 whorls. Osphradium (figures 19, 20, os) a raised ridge, squarish in cross section, darkly pig- mented and probably highly ciliated on each side. Os- phradium begins about 2 mm behind distal end of ctenid- ium and extends for % ctenidial length. It lies closely adjacent to ctenidium, but deviates from it in region of inhalant siphon. Ctenidium (figures 19, 20, ct) a narrow, large, well-developed organ comprising long, triangular filaments with finger-like tips. Each filament has a sup- porting rod along its leading edge. Hv pobranchial gland (figures 19, 20, hg) a highl\- developed, thick organ com- prising a series of thin, transparent, semicircular leaflets that run adjacent to ctenidium and extend length of mantle cavitv . Spaces between each leaflet filled with tlocculent, acellular mucus-like material that may be se- creted by epithelial lining of leaflets. Rectum (figures 19, 20, r) tubular and thick, filled with rod-shaped fecal pellets \\ ithout sand and consisting of detritus. Alimentary tract: Broad, spade-shaped snout (figure 18, sn) highh nuiscular and bearing relati\el\ large buccal mass. Pair of small, semilunar, chitinous jaws comprising man\ small, overlapping scales at tip of buccal mass. Figures 12-17. Scanning electron micrographs of radula and operculum of Fastigiella carinata (USNM 859097). 12. View of part of radular ribbon with marginal teeth spread out. Scale bar = 125 ^m '3. Half row of teeth showing long lateral tooth and narrow hooklikc marginal teeth. Scale bar = 63 ;jm. 14. Detail of rachidian tooth, showing basal plate and cu.sps of rachidian and lateral leeth. Scale bar = 25 ^m. 15. Tips of marginal teeth showing small denticles. Scale bar = 19 /um 16. Rachidian and lateral teeth showing long lateral-basal extensions of lateral teeth. Scale bar = 43 ^m, 17. Operculum. Length 8.4 mm. R. S. Houbrick et al, 198" Page 105 Page 106 THE NAUTILUS, Vol. 101, No. 3 erne cm 19 hg ct Figures 18-21. Anatomical features ol I-Mtigii'lla carinata. 18. Fxtcriial feature.s of female \ie\\'e(l from the right 14. Schematic representation of cross .section behind nerve ring show ing morphological relationships ot major mantle cavil) organs 20. .Schematic representation of section of mantle cavity organs exclusive of paUial gonoduct showing relationship of h\ pobranchial gland leaflets to rectum and ctenidiurn. 21. .Schematic representation of pallial osiduct antl its internal components, ag = albumin gland; cm = columellar mu.scle; cme = cut mantle edge; cod = coelomic oviduct; ct = ctenidium; dg = digestive gland; es = esophagus; f = fusion of lateral and medial laminae; ft = foot; hg = hypobranchial gland; k = kidney; 11 = lateral lamina; mc = mantle cavity; mg = mucus gland; nd = medial lamina; mp = mantle papillae; op = operculum; os = osphradium; ov = ovary; ovg = oviductal groove; po = pallial oviduct; r = rectum; rd = central ridge di\iding anterior o\ iductal groove; sg = sperm gutter; sn = snout; sr = seminal receptacle; st = stomach; t = cephalic tentacle. R, S. Houbrick ct al.. 19S7 Page 107 Buccal mass has long oddiitophorc, Sali\ar\ glands con- sist ot pair of \veakl\- coiled tubes that originate in front of nerve ring and empt\ at dorsal anterior part of buccal mass near jaws. Salivary glands thicker anteriorly. Mid- esophagus slightK expanded and has large dorsal food channel. Large stomach occupies about 1.5 whorls and comprises short st\le sac, hyaline gastric shield, large central pad-like ridge, and enormous sorting area. Radula (figures 12-16): Taenioglossate radula short, about '/|h shell length (L = 2.2 mm), and comprises around 2S0 tranverse rows of teeth. Rachidian tooth wider than high, with convex tip and scjuat, hourglass-shaped basal plate i figure 14). Cutting edge of rachidian tooth com- prises central cusp flanked on each side by 3 smaller denticles. Lateral tooth conspicuously large with very long lateral extension of basal plate and weak central buttress that extends posteriorly (figure 16). Cutting edge of lateral tooth serrated \\ ith 2 or 3 inner denticles, a large, pointed central cusp, and 4-6 outer denticles (fig- ure 14). The two marginal teeth (figures 13, 15) are narrow, elongate, curved hooks with pointed tips and are wider where attached to basal radular membrane. Outer marginal tooth slighth larger and less hooked than inner one. Marginal teeth serrated near their distal outer sides with 3-5 tin\', sharp denticles (figure 15). Reproductive tract: Large, acinous ovary (figure 18, ov) overlies digestive gland and occupies the first 4 or 5 w horls. It appears to consist of large cells. Female pallial oviduct (figures 19, 21) a very long open tube, comprising lateral (figures 19, 21, 11) and medial (figures 19, 21, ml) laminae connected to mantle floor along their dorsal mar- gins. Posterior end of pallial oviduct has thickened walls and is closed b\- tusion of the 2 laminae (figure 21, f). Thick albumen gland (figure 21, ag) at posterior end of pallial oviduct. Seminal receptacle (figure 21, sr) and sperm gutter (figure 21, sg) lie near posterior end of medial lamina. Oviductal groove (figure 21, ovg) formed at thick, glandular, connecting bases of these 2 laminae. Oviductal groove divided along its length by large, cen- tral ridge (figure 21, rd) that begins anteriorly and ex- tends back a little [jast midpoint of pallial oviduct. Ridge tapers and ends just anterior to opening of sperm gutter to seminal receptacle on medial lamina. This ridge ef- fectively divides anterior and median parts of the oviduct into 2 open chambers, 1 of which may function as sper- matophore bursa. Male gonoduct unknown. Nervous system: Nervous system epiathroid. Cerebral ganglia joined b\ short, but distinct, connective. Right pleural ganglion joined to right cerebral ganglion b\- short connective. Distribution and Ecology Distribution (figure 22): Fastigiclla carinata is known only from the Great Bahama Bank and the northwestern coast of Cuba. The known distribution in Cuba is from Santa Fe, S km west of Marianao, Habana, west to Car- denas (Perez Farfante, 1940;71, pi. 13, fig. 3; Sarasua & Figure 22. Geographical distribution of Fastigiclla carinata based on available records, showing disjunct range. Espinosa, 1977; USNM 434792), a coastline oiiK about 140 km long that is not the nearest part of Cuba to the Bahamas. Although previously published Bahamian rec- ords were from Andros and Eleuthera only, Fastigiclla has been found on the eastern coast of Andros Island; the northern coast of New Providence Island; the Berry Islands; the southwestern coast of Eleuthera and the near- b) Schooner Cays; Cat Island; Exuma Cays. This species appears to be absent from the Little Bahama Bank. Fastigiclla carinata seems to be fairly rare in the lo- calities discussed above, but may ocur in other parts of the Bahamas and Cluba that are not as conchologically well known. Sarasua and Espinosa (1977), who knew of 13 Cuban and only three Bahamian shells, stated that the species is more common in Cuba than in the Bahamas. VVe have been able to stud\ main Bahamian and onK 3 Cuban shells. Like such other shallow water species as Cittariuin pica (Linnaeus) and Turhinclla angulata (Lightfoot), this Bahamas-Cuba species has not been re- ported in Florida or Bermuda. Ecology: Not much can be said about the ecology of Fastigiclla. All of the shells available to us are slightly to moderately decollated (figures 6, 7), with not even part of a protoconch present. As the smallest intact w horl width is 0.7 mm, larval development could be plankto- trophic or lecithotrophic. Although spawn and larvae remain unknown, the restricted geographic range sug- gests lecithotrophy or direct development. The single, live-collected female described herein was found after a five-day blow, intertidally in a small hole on a rocky shelf bordering deeper sand and grass banks. As onlv one living specimen has loeen found, it is not certain that this is the normal habitat. Frequently , empty shells are inhabited by hermit crabs which also occur in other shallow water species such as Tegula fasciata (Born) and Ccrithium litteratuv^ (Born). The alimentary tract and fecal pellets indicate typical cerithiacean algal-de- trital herbivorv. Page 108 THE NAUTILUS, Vol. 101, No. 3 DISCUSSION Shell variation: This .species does not display the mor- phological sariatioii that is so common among cerithiid genera such as Cerithium. Clypcaruoms Jousseaume, and Rhinoctavix Swainson. Ne\ertheless, there are some variations that should be noted. Newly dead specimens ma\ have a light tan spiral band adjacent to the suture (figures 1, 2, 4). Sarasiia and Espinosa (1977:6-7) re- corded remnants of a brov\'nish orange color pattern on some Cuban shells. Differences between fully grown and immature shells are most pronounced in the columellar and siphonal areas of the bod\ v\horl. Immature shells (figure 8) lack the pseudumbilicus and siphonal fasciole that is present in fully grown specimens (figures 1-3). The narrow pseud- umbilicus, which varies in width, and the siphonal fasciole develop after the shell reaches a length of 25-35 mm. as noted by Jensen (1967). Several Cuban shells reach a length of 52-60 mm, while the largest Bahamian specimens observed are 45- 48.4 mm. FulK- mature specimens from Cuba, exceeding 35 mm in length and having a deep, narrow pseudum- bilicus, differ in having six or seven evenK-sized spiral cords on the penultimate whorl, while those from the Bahamas have oiiK three or four cords. We do not believe that this geographical difference is worthv of subspecific recognition. Cuming s specimen, illustrated b\ Reeve (1848:15) and copied by Woodward (1851), Tryon (1882), Wenz (1943), and others, is evidently a Bahamian spec- imen. Comparative eonchology: Before the live-collected specimen became available for study, one of us (Rob- ertson) noted similarities between the shells of full-grown Fastigiella and \oung Pscudovcrtagus N'ignal, a genus that has been monographed b> Houbrick (1978:99-120), In the Recent fauna, Pseudovertagiis is restricted to the tropical Indo-Pacific, where there are four species, Hou- brick classified Pseudovertagiis in the famiK' Orithi- idae, subiamiK Cerithiinae. .although full-grown shells of Pseudovertagus and Fastigiella are dissimilar, the sculpture of their upper whorls is very similar. The upper whorls of Fastigiella carinata (figures 6, 7) and Pseu- dovertagus aliico (Liiuie) (figure 9) are illustrated here. Both have three or four main spiral cords per whorl; the cords are prickly or noded; a subsutural ramp is faint to well-developed, and the whorls may or may not be slight- ly shouklered by one of the cords. Pseudovertagus and Fastigiella are the only living cerithiaceans known b\ us to have this apical sculpture. Cerithium nodulosum Bruguiere, 1792, of the Indo-Pacific, is anomalous within its genus by having apical sculpture intermediate be- tween that of CU'rithium sensu stricto and those of Pseudovertagus and Fastigiella. This suggests that these three genera may be fairly closely related. Pseudovertagus undergoes much greater ontogenetic sculptural change than Fastigiella. Fastigiella ma\ be a neotenous relative to Pseudovertagus. .Adults of the two genera both lack a prominent fold on the middle of the columella such as is present in species of Rhir^oclavis. an Indo-Pacific genus close to Pseudovertagus (see Hou- brick, 1978). The outer lip (viewed laterally) is not sin- uous in either Fastigiella (figure 2) or Pseudovertagus, as it is in Clavocerithium Cossmann. another genus close to Pseudovertagus (see Houbrick. 1978). Pseudovertagus is not congeneric with Fastigiella as there are a number of conchological and anatomical autapomorphies distin- guishing the latter taxon (see "Conclusion"). There are a few vague resemblances between Fastig- iella and Campanile Fischer (Cerithiacea: Campan- ilidae), of which one relict species occurs in southwest Australia (Houbrick, 1981a). There are two Eocene species of Pseudovertagus in France, and two Miocene and Plio- cene species in Florida (Houbrick, 1978:116-120), close to Fastigiella's range. Comparative anatomy: Stud\ of the radula and anat- omy has done much to clarif\' the systematic position of Fastigiella. Although only a single, poorly preserved specimen was studied, it was a sexualK mature female and provided most of the important characters essential for comparison with other cerithiacean taxa. Externally, the snail removed from its shell looks very much like some members of the Cerithiidae, such as Cerithium. Rhinoclavis. and Pseudovertagus. Notable features are the broad, bilobed snout, small cephalic ten- tacles, and tiny eyes (figure 18). The broad snout, con- tracted by preservation, is probably long and extensible in a living snail. In its contracted state it resembles those observed in Diastema (Houbrick, 1981b:603, fig. 2) and Campanile Desha\es (Houbrick, 1981a:269, fig, 3, a, b), some Cerithium species, and especially Pseudovertagus. The mantle edge, fringed with small papillae (figure 18, mp), and the large, thick operculum (figure 17) are typ- ical of those observed in cerithiids. The sole of the foot, particularl) the anterior portion, w as composed of thick, yellowish, hard tissue. This ma\ be an unusual feature of Fastigiella foot morphology l)ut is more likely an artifact of preservation. Man\ cerithiaceans have a cil- iated groove or ovipositor on the right side of the foot, but no trace of these structures was seen in Fastigiella. The mantle cavity is quite deep and typically ceri- thiacean in organization. The osphradium appears to be a raised ridge with w rinkled sides. It does not resemble the osphradium oi cerithiid species of comparable size, but is more like those seen in potamidids, modulids, and thiarids. An important character is the unusual hypo- branchial gland, which ciniiprises a long row of trans- verse, thin, transparent leaflets and resembles a secondary ctenidium (figure 20, hg). Between the leaflets is thick mucus-like, flocculent, granular material. Due to the poor preservation of the animal, it was not determined if this material was formed b\ a breaktlown of the epithelial lining of the leaflets or was merely hypobranchial gland secretion. The hypobranchial gland is unlike those of all other know n cerithiaceans except Pseudovertagus s|5ecies (iamily Cerithiidae), which have a iiearK idi'iitical hy- pobranchial gland (Houbrick, personal observation). The hypobranchial gland ol Cerithium nodulosum has prom- R. S. Houbrick ct ai, 19S7 Page 109 inent raised transverse ridges and nia\ be a transitional stage before the development of leaflets as found in Fas- tigiella and Psetidovcrtagtts (Houbrick, personal obser- vation). The hypobranchial gland of Campanile also has leaflets, but they are tiny and comprise many parallel rows (Houbrick. 19Sla:274. fig. 4, .\, Ihg). This gland is thus a much different structure in Campanile and its leaflet structure is not considered homologous w ith that seen in Fastigiella. The pallial oviduct is a t>picall\ cerithiacean open duct. There is no spermatophore bursa, but its fiuiction may be taken o\er b\' the large closed portion of the posterior pallial oviduct. A spermatophore bursa in the outer or inner laminae of the pallial oviduct is a common feature in most cerithiids and its absence in Fastigiella is noteworth) . This pallial o\ itluct is \ery similar to those described for many cerithiids, potamidids, and Diasioma (see Houbrick. 1974. 1978, 1981b). The posterior end of the pallial o\iduct is closed by fusion of the edges of the two laminae (figure 21, f ). The pallial oviduct of Fastig- iella differs from all other known cerithiacean pallial oviducts in having a large, swollen central ridge (figure 21, rd) at the base of the anterior oviductal groove. This ridge diminishes in size and disappears about midwa> along the pallial o\ iduct effective!}' forming two anterior oviductal grooves that merge past the middle of the pallial oviduct to form the main posterior oviductal groove. The function of this apomorphic structure is im- known. The ovar\- is large and differs from other ob- served cerithiid ovaries in being higliK acinous. Males remain unknown but, on the basis of female anatomy, are expected to be aphallate and have open pallial gon- oducts. The alimentary tract is indicative of a microphagous, herbivorous mesogastropod. The short radula is different from that of most cerithiids in having long lateral teeth with conspicuous platelike lateral extensions (figure 16) and long hooklike marginals with microscopic serrations near their tips (figure 15). Similar lateral and marginal teeth occur in the cerithiids Clavoccrithium taeniatum (Quo\- & Gaimard) and Rhinoclavis sordidiila (Gould) (Houbrick, 1975:101, figs. 9-12; 1978:71, pi. 40). Some planaxid radulae have similar lateral teeth (Houbrick. 1987). Although the sali\ar\ glands, or at least the left salivary gland, pass through the nerve ring in most cer- ithiids, the salivary glands of Fastigiella originate in front of the nerve ring. The esophagus widens behind the nerve ring, but there is no trace of an esophageal gland. A large dorsal food groove is present. The large, complex stomach with its extensive sorting area and large, raised central ridge (pad) is not unlike stomachs described for many other cerithiacean taxa. The number of openings to the digestive gland was not ascertained. CONCLUSIONS On the basis of the presence of a taenioglossate radula, proboscis structure and alimentary tract anatomy, we can confidentK state that Fastigiella is a mesogastropod (order Caenogastropoda Cox, 1959). The open pallial oviduct and internal arrangement of the seminal recep- tacle and spermatophore bursa in the medial lamina strongly support an assignment to the superfamily Cer- ithiacea. Other external anatomical structures such as the head and snout, fringed mantle edge, corneous, ovate, paucispiral operculum, aiul propodial mucus gland are characters common in many cerithiacean families. In- ternal anatomical structures of the alimentary tract are likewise consistent with the cerithiacean anatomical or- ganization. Most characters, including those of the shell, indicate the family Cerithiidae as a suitable assignment for Fas- tigiella. Ontogenetic shell characters and a few anatom- ical characters suggest a close relationship to the genus Pseudoiertagus \ignal, 1904. The unusual shell sculp- ture of three or four main spiral cords per whorl on the post-nuclear and upper whorls of Fastigiella is very sim- ilar to that seen in Pseudovertagus species. The broad snout is a character shared with Pseudovertagus. The h\pobranchial gland comprised of transverse leaflets is likewise a synapomorphous character found onl\- in Pseudovertagus and Fastigiella. The pseudumbilicus and siphonal fasciole with one to three false umbilical chinks formed b\ cord interspaces in large shells are autapomorphic characters clearly de- fining Fastigiella. Other shell characters identifying the axon are the strong spiral sculpture of three or four rounded cords per w horl, and the short, slightly reflected siphonal canal. The unusual, large ridge bisecting the anterior ovi- ductal groove of the pallial oviduct is an autapomorphy that sets Fastigiella aside as a good genus. Other non- apomorphic anatomical characters including placement anti origin of the sali\ar\ glands anterior to the nerve ring, the shape of the lateral and marginal teeth, and the unusual leaflets of the hypobranchial gland, are more equivocal, but together pro\ ide a distincti\e set of char- acters defining this taxon as a separate genus. No radular or anatomical characters have emerged from this stud\ to suggest that Fastigiella should be given a higher than generic status. Fastigiella is a relictual, and geographical!) disjunct genus (at least on the basis of a\ai!able material). We assign tliis genus in tlie Cer- ithiidae, close to the genus Pseudovertagus. Although it is unlikely that this assignment is incorrect, further study of males, other females, eggs, and !ar\ae may provide more characters supportive of this classification. Tlie sys- tematic position advocated herein is based on knowledge of a single female snail and is tentatixe until more is known about this rare animal. ACKNOWLEDGEMENTS We appreciate loans of material anti useful information from James Cordy, Merritt Id., Florida; Dieter Cosman, Ft. Lauderdale, Florida; C. John Finlay, Palm Bay, Flor- ida; Joseph \'. Lleida, Nassau, Bahamas; William G. L\ons, Marine Research Laboratory, St. Petersburg, Page 110 THE NAUTILUS, Vol. 101, No. 3 Florida; Lois F. McNeil, PKnioiith Meeting, Pennsyl- vania; Marilee McNeilus, Eleutliera, Bahamas, antl Dodge Center, Minnesota; Gary Rosenberg, Museum oi Com- parative Zoology, Harvard University, Cambridge, Mas- sachusetts; Jack VVorsfold, Freeport, Grand Bahama Id., Bahamas. Photograplu was done by Mr. N'ictor Krantz, Smithsonian Photographic Services. Rudiger Bieler, Smithsonian Marine Station, Link Port, Florida, and Pau- la Mikkelsen, Harbor Branch Oceanographic Institution, F't. Pierce, Florida, critically read drafts ol the manu- script. LITERATURE CITED Abbott, R. T. 1974. American seashells, 2iid ed. New York, 66.3 p., 24 pis. .Abbott, R. T. and P. Dance. 1982. Compendium of seashells. New York, 411 p., illus. .\dams, H. and A. Adams. 1853-58. The genera of Recent Mollusca, 3 vols. London, 389 p., 138 pis. C'lienu. J. C. 1859. Manuel de conchyliologie et de paleon- toiogie. Vol. 1. Paris, 508 p., 3707 figs. Cossmann, M. 1906. Essais de paleoconchologie comparee. Vol. 7. Paris, 261 p., 14 pis. Co.\, L. R. 1960. Thoughts on the classification of the Gas- tropoda. Proceedings of the Malacologieal Societ\ of Lon- don 33(6):239-261. Fischer, P. 1880-87. Manuel de conchyliologie et de paleon- tologie concliyliologique. Paris, 1369 p., 23 pis,, 1158 figs. Ford, P. D. 1944. .A, complete list of Bahamian shells collected and classified by the Bahamas Conchological Society Pri- vately published, Nassau, Bahamas, 11 p Houbrick, R. S. 1974. The genus Ccrithium in the western Atlantic. Johnsonia 5(50):33-84. Houbrick, R. S. 1975. Clavoccrithium (Indocerithium) tae- nialum. a little-known and unusual cerithiid from New Guinea. Tlie Nautilus 89(4):99-105. Houbrick, R. S. 1978. Tlie family Oritliiidae in the Indo- Pacific. Part 1; the genera Rhinoclavis. Psciulovcrtagus and Clavoceritbium. Monographs of Marine Mollusca No. 1:130 p., 98 pis. Houbrick, R. S. 1981a. Anatomy, biology and systematics of Campanile symbolicum with reference to adaptive radia- tion of the Cerithiacea (Gastropoda: Prosobranchia). Mal- acologia 21(l-2):26.3-289. Houbrick, R. S. 1981b. .Anatomy of Diastotna melanioides (Reeve, 1849) with remarks on the systematic position of the family Diastomatidae (Prosobranchia: Gastropoda). Proceedings of the Biological Societ\ of Washington 94(2): .598-621. Houbrick, R. S. 1987. .Anatonu, biolog\ and plnlogeny of the Plana.vidae (Cerithiacea: Prosobranchia). Smithsonian Contributions to Zoology No. 445:57 p., 27 figs., 6 tables. Jaume, M. L. and H. Sarasua. 1943. Notas sobre moluscos marines Cubanos. Revista de la Sociedad Vlalacologica "Carlos de la Torre" 1(2):52-61. Jensen, D. 1967. Fastigiella carinata, a little known species. New York Shell Club Notes 128:6-7, 1 fig. Kline, G. F. 1953. .Another specimen of Fastigiella carinata Reeve. The Nautilus 66(3): 142. Lamarck, J. B, 1804. Suite des memoires sur les fossiles des environs de Paris. Annales du Museum National d'Histoire Naturelle (Paris) 3:436-441. Moore, D. R. 1971. What is Fastigiella carinata''' Mollusk Chaser, South Florida Shell Club 9(8): 1-2 Morch. O. A. L. 1877 Description d une nou\elle especie du genre Fastigiella Reeve. Journal de Conch) liologie 25:207. Perez Farfante, I. 1940. .Adiciones a la liste de moluscos Cu- banos. Memorias de la Sociedad Cubana de la Historia Naturalia 14(l):69-73. Pilsbr) , H. .A. 1953. Fastigiella carinata Ree\ e, a Httle-know n mollusk. The Nautilus 66(3):77-78. Poulsen, C. M. 1878. Catalogue of west India shells. Copen- hagen, 16 p. Reeve, L. A. 1848. On Fastigiella. a new genus of shells of the Lamarkian famiK' Canalifera. Proceedings of the Zoo- logical Societ) of London 16:14-15. Reeve, L. .A. 18(50. Elements of concholog\ . \ dl 1. London, 260 p.. 21 pis. Sarasua, H. and J. Espinosa. 1977. Notas sobre el genero Antilliano Fastigiella (Mollusca: Mesogastropoda). Poey- ana 171:1-11. Thiele, J. 1929. Handbuch der s>stematischen Weichtier- kunde. Band 1. Teil 1 Gustav Fischer, Jena, .376 p.. 470 figs. Trvon, G. W, 1882. Manual of conchology, first series. Vol. 4. Philadelphia, p. 5-276, .58 pis. Wenz, W. 1940. Gastropoda, 1. Handbuch der Palaozoologie, Band 4, Part 4:721-960, te.xt figs. 2085-2787; 1943, Band 6, Part 1:770 p., text figs. 3417-4211. Borntrager, Berlin. Woodward, S P. 1851. A manual of the Mollusca or a treatise of Recent and fo.ssil shells. London, .338 p., figs., pis. Note added in proof: Another live specimen ot Fastigiella was recenth collected sand, at Marsh Harbour, .Aljaio, Bahamas. Ke\an Sunderland m Im depth on a patch reel, half buried on THE NAUTILUS 101(3):111-116, 1987 Page 111 Cataegis, New Genus of Three New Species from the Continental Slope (Trochidae: Cataeginae New Subfamily) James H. McLean Los Angeles Couiit\ Museum ot Natural Histor\ 900 Exposition Blvd. Los Angeles, CA 90007, USA James F. Quinn. Jr. Florida Department of Natural Resources Bureau of Marine Research 100 Eighth Ave., S,E. St. Petersburg, FL 33701. USA ABSTRACT Cataegis new genus, type species C. toreida new species, is proposed to include three new species from continental slope depths (200-2,000 m): the t>pe species and C. meroghjpta from the Gulf of Mexico to Colombia, and C. celebesensis from Makassar Strait, Indonesia. Important shell characters are the prominent spiral cords, non-umbilicate base, and oblique ap- erture. The radula is unique among the Trochidae in lacking the rachidian, having the Erst pair of laterals fused and un- cusped, and the first marginals enlarged. The gill is the ad- vanced trochid t\pe with well-developed afferent membrane. These characters do not correspond to an available subfamily; the new subfaniiK C^ataeginae is therefore proposed. INTRODUCTION The two hitherto unknown species of trochids described here from continental slope depths in the Caribbean Sea and Gulf of Mexico w ere first examined by Quinn, who noted that shell characters of the two species are unlike those of any known genus of Trochidae. Epipodial and radular characters were later examined by McLean, who found a unique combination of radular features in one of the two species. A third member of the genus from slope depths in Indonesian waters was subsequently rec- ognized by McLean in unidentified material received on loan from the Paris Museum. An unsuccessful search for a genus for these species prompted the present descrip- tion of a new genus. Although higher classification of Trochidae has been unsettled (Marshall, 1979), consideration of gill charac- ters has led to new understanding (McLean, 1982), and a full review of higher classification of Trochacea is Hear- ing completion by Hickman and McLean (in prepara- tion). Full discussion of trochacean classification is de- ferred to that review. The new genus cannot be assigned to an existing trochid subfamily, necessitating the pro- posal of a new subfamily. Institutional abbreviations used here are: ANSP (Acad- emy of Natural Sciences, Philadelphia); FSBC I (Florida Department of Natural Resources, Bureau of Marine Re- search, St. Petersburg); FSM (Florida State Museum, Uni- versity of Florida, Gainesville); LACM (Los Angeles County Museum of Natural History, Los Angeles); MCZ (Museum of Comparative Zoology, Harvard University, Cambridge); MNHN (Museum National d'Histoire Na- turelle, Paris); TAMU (Invertebrate Collection, Texas A&M University, College Station); UMML (Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, Coral Gables); USNM (U.S. National Museum of Natural History, Washington). SYSTEMATICS Family Trochidae Cataeginae new subfamily Type genus: Cataegis new genus. Diagnosis: Shell non-umbilicate, with strong spiral cords, nacreous interior, oblique aperture, non-plicate colu- mella, multispiral operculum. Left gill bipectinate with long afferent membrane pos- terior to free tip. Snout expanded at tip; cephalic ten- tacles « ith broad bases, eyes on short peduncles; cephalic lappets lacking; epipodial tentacles small; left and right neck lobes well developed, finely fringed at edges; left neck lobe folded over, evidently capable of rolling to form incurrent siphon. Radula lacking rachidian; lateral teeth 4 pairs, inner laterals fused, uncusped; second, third, and fourth lat- erals with simple, tapered, overhanging tips, shafts elon- gate with narrow frontal elements and large, triangular rear elements; inner edge of rear element interlocking with corresponding depression on outer edge of adjacent lateral tooth; latero-inarginal plate not evident; margin- als numerous, first marginal enlarged, second and third marginals decreasing in size, remaining marginals with sickle-shaped tips and up to 6 blunt denticles on each side of tip. Discussion: .Although shell characters are of minor im- portance in suprageneric classification of trochids, the combination of shell characters (strong spiral cords, lack Page 112 THE NAUTILUS, Vol. 101, No. 3 Figures 1-5. Shells of new species of Catacgis, apertural and basal views. 1, 2. Cataegis toreuta new species, 1. Holot\pe, off Colombia, USNM 784755, height 21.8 mm. 2. Paratype. off Biloxi, Mississippi, USNM 801816, height 19.3 mm. 3, 4. Cataegis meroglypta new species. 3. Holotype, off Mississippi River Delta, Louisiana, MNHN uncat., height 17.8 mm. 4. Parat\pe, off Colombia, USNM 784757, height 16,9 mm. 5. Cataegis celebesensis new species. Holotype, MNHN uncat., Makassar Strait, Celebes, Indonesia, height 20.4 mm. of coluineiiar plications, oblique, broadly expanding ap- erture) in Cataegis is unique. Epipodial characters are llio.se of generalized trochids in having well-developed left and right neck lobes, al- though most trochids have cephalic lappets and better- developed epipodial tentacles. Most deeper water trochid genera are included within the broadly defined subfam- ily Margaritinae (as used In Keen in Moore, 1960); these genera have in common a thin shell and most lack col- umellar plications. On shell and external anatomical characters it seemed likely that Cataegis should be re- lated to such margariline genera as Cidarina Dall, 1909. McLean (1982) noted, however, that genera ol the old group "Margaritinae" have a primitive gill structure in which the afferent membrane is short, ('ontrarv to all expectations for a deep-water genus, the gill structure ol Cataegis is advanced, with a long afferent membrane like that of genera of the subfamilies Monodontinae, Trochinae, C-'alliostomatinae, and Solariellinae (as used by Keen in Moore, 1960). The new subfamilial classification of Trochidae to be introduced by Hickman and McLean (in preparation) is, in large part, based upon a discrete radular plan for each subfamily. The radula of Cataegis fits nowhere within this scheme but represents yet another unique plan. .Al- though there are genera in which the rachidian is un- cusped, no other trochid group completely lacks the ra- chidian tooth and no other group exhibits a fusion of the bases of the first pair of lateral teeth, torming a "central element" that replaces the rachidian. The interlocking of the laterals is also unique; other radular plans show- interlocking of the lateral teeth in different ways (for J. H. McLean and J. F. Quinn, Jr., 1987 Page 113 Figures 6-8. External anatoiin of Cataegis, photographs of retracted bodies, 6. Cataegis torcuta new species (sta. P-388). 7. 8. Cataegis meroglypla new species (holot\'pe). Bar = 2 mm, C, ctenidium; E, eye; F, foot; L, left neck lobe; O, operculum; R, right neck lobe; S, snout; T, cephalic tentacle. discussion see Hickman, 1984). Enlargement of the first marginal is a character state of the Caliiostomatinae, but other features of the radula and external anatomy of Calliostoma Swainson, 1840, are missing. Cataegis new genus Type species: Cataegis toreuta new species. Diagnosis: Shell of moderate size (to about 25 mm in height), turbinate, slightly wider than high, non-umbil- icate, with strong spiral sculpture; white under greenish- brown periostracum. Whorls well rounded, with about 7-12 strong, irregularK rugose or fineK' nodose spiral cords; axial sculpture of nodes or limited to strong growth lines; base rounded, aperture oblique, circular, nacreous within; outer lip thin, fluted by spiral sculpture; colu- mella smooth, thickened, evenly arcuate. Operculum corneous, thin, circular, multispiral, w ith central nucleus. Characters of gill, external anatomv, and radula as described above under subfamilial diagnosis. Distribution: Cataegis is known from the three new- species here described; the type species C. toreuta, C. meroglypta (both known from contiguous continental slopes of the mainland extending from the Gulf of Mexico to Colombia), and C. celebesensis at similar depths from Indonesia. The existence of two Caribbean species plus C. celebesensis in the Indo-Pacific faunal province in- dicates that the distribution of the genus is Tethx an and at least Cretaceous in origin. Until continental slope depths of other regions of the world are adequately sampled, it is unknown whether the present distribution is that of a relict genus, although that is the most likely explanation. All records for this genus are from continental slope depths, suggesting that the genus survives in relatively deep water. This agrees with the conclusion of Jablonski et al. (1983) that evolutionary innovations arise in shallow water and survive extinction by retreating offshore to deeper water where conditions are more stable. Gut contents of the specimen of Cataegis toreuta from which the radula was prepared (figures 9, 10) included numerous pieces of plant remains identified as the Ca- ribbean turtle grass, Thalassia testudinum. remains of which are common in the deep sea and continental slopes (for review see Wolff, 1979). The ready availability of this food may be a factor relating to the relatively large size of members of the genus. It lends further support to the hypothesis that the group originated in shallow water, the source of the food supply. Etymology: Latin cataegis (from Greek kataigis). a feminine noun meaning hurricane or whirlwind, with reference to the strong spiral sculpture. Cataegis toreuta new species (figures 1, 2, 6, 9, 10) Description: Shell (figures 1, 2) attaining 24.6 mm in height, 25. 1 mm in diameter, turbinate, non-umbilicate, rather thick and solid, white. Periostracum thin, decid- uous, light brown. Protoconch diameter 400 /xm. Teleo- conch w horls 5, rapidly expanding, last whorl well round- ed. Spiral sculpture of 8-12 (usually 9) strong cords with broad, strongly concave interspaces; interspaces with fine Page 114 THE NAUTILUS, Vol. 101, No. 3 Figures 9-12. Hadulat- ol ialacgis. SEVl micTugraphs. 9, 10. CUitavgis tarcnta new species (sla 71-,\7-ll), slidwiiig liised first laterals, second, third, and fourth laterals, enlarged first marginal and succeeding pairs of marginals (scale bar of 9 = 50 ^m, of 10 = 20 ^m). 1 1, 12. Cataegis celebesensis new species (holotvpe), showing same features (scale bar of 11 =50 ^"1, of 12 = 20 Mm)- intercalary spiral threads. A.xial sculpture on second and third whorls of regularly spaced, oblique folds forming sharp nodes on crossing primary spirals; thiril to fifth whorls with close-set, irregular collabral grov\tli lines forming low, sublamellar nodes on primary spiral cords. Base not distinct from rest of whorl, with umbilical depression. Aperture nearly circular, nacreous within; outer lipstrongK prosocline, fluted by external sculpture; columella arcuate, thickened, smooth, with thin wash ot nacre; inner lip reflected, thickened, usually concealing umbilical depression; parietal wall with thin porcela- neous callus. Operculum corneous, thin, amber, multispi- ral with numerous volutions. Dimensions: Holotype: height 21.8 nun, diameter 22.9 nun; largest specimen: height 24.6 mm, diameter 25.1 mm. Gill and external anatom> (figure 6) as described above under subfamily diagnosis. Radula (figures 9, 10) lacking rachidian; lateral teeth 4 pairs, first laterals fused at base, uncusped; .second, third, and fourth laterals with simple, tapered, over- hanging tips; shafts elongate with narrow frontal ele- ments and large, triangular rear elements; inner edge of rear element interlocking with corresponding depression on outer edge of adjacent lateral tooth; latero-marginal plate not evident; inarginals numerous, shaft of first mar- ginal tw ice breadth of the second; .second marginal twice thickness of third; remaining marginals decreasing in J. H. McLean and J. F. Quinn, Jr., 1987 Page 115 size, with sickle-shaped tips and up to 6 blunt denticles on each side of tapered tip. Type locality: W of Punta Piedras, Colombia, 9°20.2'N, 76°34.2'W, 933-961 m. Type material: Holotspe: USNM 784755, John Elliott Fillsbunj sta. P-364, 10' otter trawl, July 13, 1966 (figure 1). Paratypes (by vessel and station number): John Elliott Pillsbimi sta. P-381, off Colombia, 10°17'N, 75°59.9'W. 733-604 m; 2 specimens, L'MML 30.3420; 2 specimens, LACM 2264, John Elliott Pillsbury sta. P-38S, off Colombia, 10°16'N, 76°03'\V, 824-1,061 m; 1 specimen, UMML 30.3429. John Elliott PiUslmnj sta. P-394, oft Colombia, 9°28.6'N, 76°26.3'W, 421-641 m; 4 specimens, UMML 30.3498. John Elliott Pilhlniri/ sta, P-407, off Colombia, 9°00.2'\, 77°25.3'\V," 1,171-1,239 m; 3 specimens, USNM 784756; 2 specimens, MCZ 296111; 2 spec- imens, ASNP 359168; 2 specimens, FSBC I 31770; 2 specimens, UMML 30.3576. John Elliott Pillslnirii sta. P-413, off Colombia, 9°01.5'N, 76°53'\\', 1,281-1,283 m; 3 specimens, UMML 30.3607. Oregon II sta. 4580, off Bilo.xi, Mississippi, 29°06'N, 88°06'W, 805 m; 1 specimen, USNM 801816 {figure 2). Oregon II sta. 11228, off Panama, 9°05'N, 81°18'W, 594 m; 7 specimens, FSM 28719. Oregon II sta, 39554, off Corpus Christi, Te.xas, 27°25.7'N, 95°54,2'W. 337-412 m; 1 specimen, FSM 40669, Alaminos sta. 68-A7-10A, off Pensacola, Florida, 29°15.5'N, 86°55'W, 541 m; 1 specimen, MNHN uncat. Alaminos sta. 6S-A7-15I1, off Pensacola, Florida, 29°10,5'N, 87°16'W, 914 m; 1 specimen, MNHN uncat. Alaminos sta, 69-.'Ml-64, off Vera Cruz, Mexico, 19°28'N, 95°58'W. 384 m; 1 specimen, TAMU 4-1954. Alaminos sta. 71-A7-11, off Brownsville, Texas, 26°32.3'N, 96°05'W, 636 m; 1 specimen, MNHN uncat. (figures 9, 10, radula). Alaminos sta. 71-A8-47, off N'era Cruz, Mexico, 21°35'N, 96°54.6'W, 937 m; 1 specimen, MNHN uncat. Distribution: Western .\tlantic, off Pensacola, Florida, to Colombia, continental slope depths, 337-1,283 m. Etymology: Greek torenta. masculine noun in apposi- tion, worker using a lathe. Remarks: This is the best represented of the three species of Cataegis. It is the only species in which the nodose axial sculpture persists in later whorls. The radula differs from that of C. celebesensis in having the first marginals more prominent, and in more clearK- indicating that the central element represents a fusion of the first lateral teeth (figure 10), Cataegis meroglypta new species (figures 3, 4, 7, 8) Description: Shell (figures 3, 4) attaining at least 17.8 mm in height, 18.9 mm in diameter; turbinate, rather thick and solid, white. Periostracum thick, brown to greenish-brown. Protoconch unknown (eroded on all specimens). Teleoconch whorls 3.5, rapidly expanding, last whorl well rounded. Spiral sculpture of 4 or 5 strong spiral cords adapicallv' and 6 or 7 on base; cords irreg- ularly rugose, but not distinctK beaded; interspaces be- tween primary spiral cords smooth or bearing as many as 5 w eak spiral threads. Axial sculpture on first 2 whorls of low, oblique folds radiating from suture to first pri- mary cord; later whorls with low, irregular, rugose, col- labral grow th lines. Base not distinct from rest of whorl, with central vunbilical depression. Aperture nearly cir- cular, nacreous within; outer lip strongK- prosocline, sliglitly fluted b\ external spirals; columella arcuate, thickened, smooth, with thin wash of nacre; inner lip reflected, forming rather thick, porcelaneous callus con- cealing most of umbilical depression; parietal wall with thin wash of porcelaneous callus. Operculum corneous, thin, amber, multispiral with numerous volutions. Dimensions: Holot\ pe: height 17.8 mm, diameter 18.9 mm; paratype: height 16.9 mm, diameter 18.4 mm. Gill and external anatom\ (figures 7, 8) as described above under subfamily diagnosis. Radula not examined (body of holotype maintained intact). Type locality: S of Mississippi River Delta, Louisiana, 27°49'N, 90°07'\^^ 845-858 m. Type material: Holot\pe: MNHN uncat., LGL Cruise l-MMS-Co (figure 3). Paratypes (empty shells): John El- liott Pillsbunj sta. P-394, W of Punta Piedras, Colombia, 9°28.6'N, 76°26.3'W, 421-641 m; 1 specimen, USNM 784757 (figure 4); 2 specimens + 1 fragment, UMML 30.3499. Distribution: Western Atlantic, Louisiana to Colombia, continental slope depths, 421-858 m. Etymology: Adjective derived from Greek: meros. part, and glyptos. carved. Remarks: Cataegis meroglypta tliffers from C. toreuta new species in having fewer, weaker spiral cords that are irregularis rugose rather than discretely nodulose, weaker spiral threads between the adapical cords, and a thicker, darker periostracum. Cataegis celebesensis new species (figures 5, 11, 12) Description: Shell (figure 5) attaining 20.4 mm in height, 20.3 mm in diameter, turbinate, non-umbilicate, rather thick and solid, white. Periostracum thin, deciduous, light brown. Protoconch unknown (eroded in holotype). Tel- eoconch whorls 4, rapidh expanding, last whorl well rounded. Spiral sculpture of 8 strong cords with broad, Page 116 THE NAUTILUS, Vol. 101, No. 3 strongly concave interspaces; fine intercalary spiral threads present in interspaces. Axial sculpture of irreg- ular rugosities on spiral cords and close-set, irregular collabral grow tli lines. Base not distinct from rest of whorl. Aperture nearly circular, nacreous within; outer lip strongly prosocline, fluted b\ external sculpture; colu- mella arcuate, thickened, smooth, with thin wash of na- cre; inner lip reflected, raised over umbilical depression; parietal wall w ith thin porcelaneous callus. Operculum corneous, thin, amber, multispiral w ith numerous solu- tions. Dimensions: Holotype: height 20.4 mm, diameter 20.3 mm. Gill and external anatomy as described above under subfamily diagnosis. Radula (figures 11, 12) lacking rachidian; lateral teeth 4 pairs, inner laterals uncusped, fused at base, fused area buckling forward; second, third, and fourth laterals w ith simple, tapering, overhanging cusps; shafts elongate with narrow elements and larger, triangular rear elements; inner edge of rear element interlocking w ith correspond- ing depression on outer edge of adjacent lateral tooth; latero-marginal plate not evident; marginals numerous, innermost marginals slightly larger than remaining mar- ginals, with sickle-shaped tips and up to 6 blunt denticles on each side of tip. Type locality: Maka.ssar Strait, off W side Minahassa Peninsula, Celebes, Indonesia, 0°05'S, 119°4S'E, 1,080 m. Type material: Holot\ pe: MNHN uncat., Corindon Ex- pedition sta. 231 (figure 5). Paratvpe (dr\ with opercu- lum in place): Albatross sta. 5668, Makassar Strait, In- donesia, 2°28'S, 118°49'E, 1,647 m; 1 specimen, USNM 239507. Distribution: Makassar Strait, Indonesia, 1,080-1,647 m. Etymology: The name is an adjective derived from Ce- lebes Island Remarks: Cataegis celebcscnsis ilifters from C. toreuta in having a higher profile ot fewer whorls and in lacking the pronounced axial nodes of that species. The radula of C. celehesensis has first marginals that are not as enlarged as those of C. toreuta. The illustrated prepa- ration of the radula of the holotype shows the fused first lateral teeth in nearly perfect condition (figure 12). The regular outline of the first laterals in successive rows shows that cusps were not formed and eliminates the possibilit\ that the cusps were simpK worn down. ACKNOWLEDGEMENTS We thank the following curators for access to material in collections under their care; P. Bouchet (MNHN); R. S. Houbrick and the late J. Rosewater (USNM); G. L. Voss (UMML); F. C. Thompson (FSM); and L. Pequenat (formerly TAML'). Photographs of the bodies were made by B. C. Draper, volunteer at the LACM. SEM micro- graphs of radulae were made at the Center for Electron Microscopy and Microanalysis, University of Southern California, Los Angeles, with the assistance of C. Coney, LACM. We thank C. S. Hickman, L'niversity of Cali- fornia, Berkeley, for helpful commentary. LITERATURE CITED Hickman, C. S. 1984. Implications of radular tooth-row func- tional integration for archaeogastropod svstematics. Mal- acoiogia 25:143-160- Jablonski, D., J. J. Sepkoski, Jr., D. J. Bottjer, and P M. Sheehan. 1983. Onshore-offshore patterns in the evolution of Pha- nerozoic shelf communities. Science 222:1123-1125. Keen, A. M. 1960. [Cenozoic Archaeogastropoda] /n.- Moore, R C. (ed). Treatise on invertebrate paleontology. Part I, Mollusca 1, Geological Societ\ of America and University of Kansas Press, Lawrence, \ii + 351 p Marshall, B. A. 1979. The Trochidae and Turbinidae of the Kermadec Ridge (Mollusca: Gastropoda). New Zealand Journal of Zoology 6:521-552. McLean, J. H. 1982. Importance of gill structure in trocha- cean classification. The Western Society of Malacologists. Annual Report 14:11, Wolff, T. 1979, Macrofaunal utilization of plant remains in the deep sea, Sarsia 64:117-136. THE NAUTILUS 101(3):117-132, 1987 Page 117 Significance of Radular Characters in Reconstruction of Thaidid Phylogeny (Neogastropoda: Muricacea) Silvard P. Kool Department of Biological Sciences The George Washington Lini\'ersity Washington, DC 20052, USA maihng address: Department of Invertebrate Zoology National \4useum of Natural History Smithsonian Institution Washington, DC 20560, USA ABSTRACT Radulae of 16 species representing nine thaidid genera were examined using scanning electron microscop\ . Radular char- acters of thaidid gastropods are incongruent with existing taxo- nomic schemes based on conchology, but highly congruent with ph\logenetic schemes based on anatomy, and seem to be ev- olutionaril) conservative. Correlation analyses of the relation- ship between radular morpholog) and diet were done to de- termine if radular morpholog) is indicative of the t\pe of food eaten. Results show no significant correlation between the two variables. Congruence of radular morphologs with a classifi- cation based on anatomical data, and the absence of correlation between radular morphology and diet, are evidence that rad- ular characters are valid indicators of phylogeny for thaidid gastropods. Furthermore, the data suggest that diet does not present a strong selective force in the evolution of radular morpholog) in thaidid gastropods INTRODUCTION Thaidid gastropods comprise a conglomerate of disparate muricid ta.xa, inhabiting mostK' intertidai epifaunal hab- itats in temperate and tropica! regions. Considerable in- stability exists in the supraspecific classification in this group. Some authors (Keen, 1971a, b; Radwin & D'Attilio, 1971, 1972, 1976; Golikov & Starobogatov, 1975; Hara- sewych, 1984) accord familial rank to this group (Thai- didae Jousseaume, 1888). Others (Cernohorsky, 1969. 1982, 1983; Emerson & Cernohorsky, 1973; Ponder, 1973; Abbott, 1974; Fujioka, 1985) treat it as a subfamily (Thai- dinae Suter, 1913, less commonly as Purpurinae Menke, 1828) of Muricidae Rafinesque, 1815. Preliminar>' ana- tomical in\estigations suggest a subfamilial status for this group {Kool, in preparation). All classifications of thaidid ta.xa to date are reliant on shell morphology (Reeve, 1846; Thiele, 1929; Wenz, 1941; Keen, unpublished manuscript). A number of authors (Colton, 1922; Moore, 1936; Hoxmark, 1971; Kitching & Lockwood, 1974; Balaparameswara Rao & Bhavanaray- ana, 1976; Spight. 1976; Vermeij, 1979; Vermeij & Cur- rey, 1980; Crothers, 1983) have reported on the consid- erable effects of environmental influences on thaidid shell morphology. Comparisons of classifications based on shell morphology with those based on anatomical characters (Kool, 19S6a,c. and in preparation), have revealed con- vergence in shell morphology, and suggest that classifi- cations based soleK on conchological characters are un- reliable. Many authors (Troschel, 1856-93; Cooke, 1919; Thiele, 1929; Clench, 1947; Arakavva, 1962. 1964; Radwin & Wells, 1968; Wu, 1968. 1973. 1985; Radwin & D'Attilio. 1971, 1972, 1976; Emerson & Cernohorskv, 1973; Ban- del, 1984; Harasewych. 1984; Fujioka, 1985) have pro- posed or discussed classifications of the thaidids, based on radular and conchological characters. Many of these authors have discussed cases of incongruence between classifications based on shell shape and those based on radular morphologv . Different radular morphologies have been found in congeneric species, while similar radulae frequently occur in different genera. A lack of congru- ence between classifications based on shell shape and those based on radular characters ma\ be due to con- vergence in shell shape or convergence in radular mor- pholog}-, perhaps determined by diet, or differential di- vergence. The purpose of this study is three-fold. In the first section, a classification based on radular characters is compared with one based on anatomical data. Congru- ence between a generic classification based on anatomy (not on radular data) and a scheme based on radular characters, may indicate that radular characters are valid indicators of phylogeny rather than manifestations of an external selective pressure such as diet (Kool, 1986b:233). In the second part of this paper, overall correlation is measured between radular morphology and diet by cal- culation of correlation coefficients for the total data set as well as several subsets. Thirdly, all species pairs were divided into nine ar- bitrarily set categories based on radular and dietar\ sim- ilarities to detect patterns of relationship between radular morphology and diet. Detection and quantification of similarity other than similarits b> descent (i.e., conver- gence) is possible b\ differentiating pairs of congeners from pairs of intergeners. The degree of congruence between radular and dietary similarities in pairs of con- geners and intergeners may provide insight into the role Page 118 THE NAUTILUS, Vol. 101, No. 3 Table 1. Radular characters used in correlatuiii studies and cladistic analysis. Character states followed by reference to illustrative figure. 1) Central cusp (ccl morpholug) ; a = triangular elongated, wide base (figure 10) b = thin, needle shaped (figure 13) c = base constricted ifigure 40) d = triangular, Dap-like, base extremely wide (figure 31) 2) Longitudinal cavity in central cusp; a = absent (figure 46) b = present (figure 49) 3) Denticle between central and lateral cusp (Ic): a = present (Id), separate from central and lateral cusp (figure 42) b = present (idle), high on lateral cusp (figure 34) c = present (idle), low on lateral cusp (figure 4) d = absent (figure 31) 4) Lateral cusp orientation: a = pointing outward, outer edge concave (figure 49) b = straight, or slightly inward (figure 13) 5) Outer denticle(s) on lateral cusp: a = absent (figure 46) b = present as low serrations (Ics) (figure 7) c = present, single (odlc) (figure 25) d = present as long distinct denticles (figure 16) 6) Area between lateral cusp and side of rachidian: a = small, sloping down towards outside (figure 52) b = wide, horizontal (figure 46) 7) Marginal denticles (md): a = absent (figure 46) b = present, distinct, elongated (figure 40) 8) Position of lateral cusp relative to marginal edge: a = lateral cusp and marginal edge oriented in similar direction (not figured) b = lateral cusp and marginal edge oriented in different directions (not figured) 9) Marginal cusp (mc): a = absent (figure 46) b = present, well defined, about the size of marginal denticles (figure 25) c = present, distinctly longer and more robust than marginal denticles (figure 37) d = very small and inconspicuous 10) Lateral extension of rachidian base: a = absent (figure 49) b = present, elongated (figure 7) c = present as small lateral protrusion (figure 34) 11) Lateral tooth: a = smooth (figure 33) b = serrated at base (figure 30) 12) Lateral tooth length: a = longer than rachidian wiilth (figure 30) b = equal to rachidian width (figure 36) c = shorter than rachidian « idth, but longer than '/4 rachidian length (figure 21) d = shorter than ': rachidian uidlli (figure 241 difl ma\ pla\ on the evolution ot radular morphology. For example, if a high degree of such correspondence is found between intergeneric specie^s pairs, the h\ pothesis that diet has had significant influence on the evolution of radular morphologv is plausible; an absence of cor- relation between radular and dietary similarities in pairs of intergeners ma\ indicate that diet has not contributed detectably to radular morphology. Thaidid gastropods are very suitable for correlation studies between radular morphology and anatomy, and radular morphology and diet, because the necessar>' data are readily available .\dditionall\ , substantial interspe- cific variation in diets and radulae facilitate detection of correlation patterns (if present) between radular mor- phologv and diet. MATERIALS AND METHODS Radular data are based on the following specimens (num- bers in parentheses indicate number of individuals): Niicella lapillm (Linne, 1758): (3) Kitterv, Maine, USA, USNM No. 836050; (3) Pemaquid Point, Maine, USA, USNM No. 857053 Niicella lamellosa (Gmelin. I79I): (4) Deception Pass, Fidalgo Island, Puget Sound, Washington, USA, USNM No. 841242 Niicella emarginata (Deshaves, 1839): (5) Bamfield, Brit- ish Columbia, Canada, NMNH No. 857054 Concholcpas concholepas (Bruguiere, 1789): (2) Val- paraiso, Chile, USNM No. 857055 Plicopurpiira patula (Linne, 1758): (5) South Miami Beach Inlet, Florida, USA, USNM No. 857056 Drupctla cornus (Roding, 1798): (2) Pago Bay, Guam, USA, USNM No. 857057 Vexilla vcxillum (Gmelin, 1791): (2) Pupukea Beach, Oahu, Hawaii, USA, USNM No. 836956 Morula ttva (Roding, 1798): (3) Pago Ba\, Guam, USA, USNM No. 857058 Morula granulata (Duclos, 1832): (2) Magnetic Island, Queensland, Australia, USNM No. 842658 Driipa morurn Roding, 1798: (4) Pago Bay, Guam, USA, USNM No. 857059 Drupa nibusidaeiis Roding, 1798: (2) Pago Ba\, Guam, USA, USNM No. 857060 Drupa ricinus (Linne, 1758): (3) Pago Bav, Guam, USA, USNM No. 857061 Drupa grossularia Roding, 1798: (2) Pago Ba\, Guam, USA, USNM No. 857062 Stramonita haemastoma (Linne, 1767): (4) Sebastian In- let, Sebastian, Florida, USA, USNM No. 857062 Purpura panania Roiling, 1798: (2) Salt Rock, Natal, South Africa. South .\frican Museum Purpura harpa Conrad, 1837: (3) Makapuu, Oahu, Ha- waii, USA, USNM No. 836958 Muricanlhus fulvescens (Sowerbv, 1834): (2) Cape Ca- naveral, Florida, USA, USNM No. 857064 Muricanlhus fulvescens is a representative of the sub- lamiK Muricinae, a sister group of the thaidids, and is used as an outgroup in the cladistic analysis. Some of the generic reallocations of the above species have been pub- lished; \ucella Roding, 1798, and Stramonita Schu- S. P, Kool, 1987 Page 119 macher, 1S17, are anatomicall\ \er\ distinct from Timis Roding, 179S (Kool 1986a:110. and in preparation). Pli- cupurpura Cossniann, 1903, is ver\ different from Pur- pura Bruguiere, 17S9, in its anatomy (Kool, 1986a:110, and in preparation). The nominal thaidid species harpa seems thus far to be closeK linked with Purpura serjsu stricto. Recognition of other thaidid genera used herein (Morula Schumacher, 1S17, Drupa Roding, 1798, W.v- illa Swainson, 1840, Drupella Thiele, 1925, and Con- cholepas Lamarck, 1801) is based on anatomical data (i.e., exclusive of radula) also. Radulae (two to six per species) were dissected from live and preserved animals, cleaned in KOH, and ex- amined using a variety of scanning electron microscopes. Four micrographs were taken of the central portion of each radular ribbon. The first two photographs (one in- cluding lateral teeth, one excluding lateral teeth) were taken perpendicular to the radular ribbon. The radula was tilted laterally to an angle of 40 degrees for a third photograph, to obtain a lateral view of the cusp and denticle morpholog\ of the rachidian tooth. FinalK', the radula was tilted laterally to an angle of about 85 degrees for a fourth photograph, used to examine the edge of the rachidian tooth and the angles, sizes, and locations of its cusps and denticles. Characters and character states, derived from anal\ sis of these photomicrographs, are presented in table 1. In- tra-specific variation was not assessed, as onl\ several specimens of each species were examined. Terminology used for the cusps and denticles of the rachidian tooth (figure 1) is largely taken from P\ijioka (1985), with the following modifications. The term "out- er denticles" (odlc) is used herein to describe onl\- the denticle(s) on the outer side of the lateral cusp. The term "lateral cusp serration (Ics) is chosen herein to describe mc cc Figure 1. Schematic drawing of composite thaidid rachidian tootii, mc = marginal cusp, md = marginal denticle, Ics = lateral cusp serration, Ic = lateral cusp, idle = inner denticle on lateral cusp, cc = central cusp. Id = lateral denticle (ho- mologous with idle), odlc = outer denticle on lateral cusp (ho- mologous with Ics). a series of small denticles on the outer side of the lateral cusp, which are homologous with the outer denticle(s) (odlc). Denticles on the outer side of the lateral cusp, but separated from it, are here called "marginal denticles" (md). A distinction is also made between an inner den- ticle on the lateral cusp (idle), and a lateral denticle (Id), which is free of the lateral cusp, but is homologous with the inner denticle. Some subjectivit\ is involved in de- termining when denticles can be deemed free of the lateral cusp. Table 2. Character matrix (see table 1) for taxa used in correlation studi les and c ladistic analvsis. Characte rs and character states Taxon 1 o 4 5 6 / 8 9 10 11 12 Nucella lapilhis b a e b b a a b b b a c S'ucella emarginata b a b b b a a a b b a c Nucella lamellosa b a e b b a a b b b a c Plicopurpura patiila b b a a a a a a a a a a Concholepas concholepas a a b a b a a a d a a a Vexilla cexillum d a d b a a a a a a b a Morula granulata b a a b a b a a a a a c Morula una b a a b a b b a b a a c Drupa morum b a c b d b b a c a a c Drupa ricinus b a b b c b b a b a a c Drupa rubusidacus b a c b a h b a b a a c Drupa grossularia e a b b e b b a b c a d Purpura harpa c a c b c b b a e e a b Purpura panama e a c b e b b a c c a b Stramonita haemastoma c a b b b a a a b e a b Drupella cornus d a a b b a a a a a b a Muricanthus fuhrsceiu' a a a a a a a a a a a a ' Outgroup in cladistie anaUsis; not used in eorrel; it ion : studies. Page 120 THE NAUTILUS, Vol. 101, No. 3 Table 3. Sources of information on tliaidid diets. Taxon Authcirs Nucella lapillus Nucella emarginuta Nucella lamellosa Concholepas conchnlepaa Plicopurpura patula Purpura pan a ma Purpura harpa Drupa niorum Drupa ricinus Drupa ruhusidaeus Drupa grossularia Stramonita hacrriasfoma Morula uva Morula gran u I at a Drupella cornus Vexilla cexilhmi Connell, 1961; Oothers, 1985; Largen, 1967; Menge, 1978; Moore, 1936 Connell. 1970; Enilen, 1966; Kool, personal obsersation; Spight, 1979, 1982; Sucha- nek, 1978 Connell, 1970; Spight, 1979, 1982; Sucha- nek, 1978 Gallardo, 1979 Bandel, 1984; Clench, 1947; Kool, personal observation Taylor, 1971, 1976 Ka\, 1979; Kool, personal observation Bernstein, 1974; Ka\. 1971, 1979; Taylor, 1968, 1983, 1984; Thomas and Kohn, 1985 Bernstein, 1974; Kay, 1971; Taylor, 1976, 1978, 1983, 1984;' Thomas and Kohn, 1985; Wu, 1965a Taylor, 1983 Taxlor, 1983, 1984 Butler, 1985; Cake, 1983; Gunter, 1979; Kool, personal observation; St. Amant, 1938 Kay, 1971; Miller 1970; Taylor, 1976, 1984 Bernstein, 1974; Kay, 1979; Kool, personal observation; Miller, 1970; Tavlor, 1968, 1971, 1976; Wu, 196.5a Demond, 1957; Kay, 1979; Kool, personal observation; Robertson, 1970; Taslor, 1976, 1978 Ka\, 1979; Kool, personal observation Dietary data were obtained troiii the literature as well as from personal field observations (table 3). Prey items were categorized as follows: (1) shelled mollusks, (2) bar- nacles, (3) other small crustaceans, (4) errant polychaetes, (5) coral polyps, (6) echinoids, (7) holothurians, and (8) sponges. No separate category was established for tubic- ulous polychaetes or sipunculans (eaten by very few species in this analysis), which were included with shelled mollusks and errant polychaetes, respectively, based on similarity in outer body coverings. Twelve radular characters, comprising 35 character states (tables 1, 2), were employed for a cladistic analysis using PHYSYS (Farris & Mickevich, copyright 1985). Muricanthus fulvescens was u.sed as an outgroup to po- larize character states. Multistate characters were kept "unordered so that any unique character state could be derived directly from the ancestral state. No further a priori assumptions were made about transformation se- ries. Dietary items were superimposed on the cladogram, to examine possible correlation betw een exolution of rad- ular morphology and dietary patterns. Two similarity coefficients were calculated for each possible pairwise comparison between species, one based on radular morphology, one based on diet. These simi- larity coefficients were then used to calculate a corre- lation coefficient between radular and dietary similari- ties. The number of positive radular character state match- es were divided by the number of characters (12). Thus, 13 different values for the radular similarity coefficient were theoretically possible. Although a binary (presence/ absence) coding method appeared to be the best way to treat dietary data, it did not allow differentiation be- tween "'main' and "supplemental ' food items. A quan- titative factor was introduced by scoring main food items "11 , supplemental prey "01 , and excluded food items "00". The coefficient of Jaccard (Sneath & Sokal, 1973: 131) was then used to calculate dietary similarity be- tween species. This similarity coefficient seemed most appropriate, because it disregards negative (0-0) match- es, which are based on the absence of a food item in the diets of both taxa. The relative terms "main " and "sup- plemental" were arbitrarily derived from quantitative studies in the literature: prey was considered "supple- mental" if eaten as a very small percentage (< 10%) in relation to the main food item. Data from non-quanti- tative studies required more subjective interpretations. Terms such as "were occasionally eaten" or "in one in- stance" assisted in these interpretations. More precise quantification of diet was impossible due to the variety of ways in which feeding data are presented in the lit- erature. Thus, if one species feeds on mollusks but not on bar- nacles, and another feeds rarely on mollusks, but mainly on barnacles, the scoring patterns would be 11-00 and 01-11, respectively. A comparison of these species would produce a similarity coefficient of 1/4, or 0.25. \ com- parison between species scored as 1 1-00 and 01-00 would result in a similarity coefficient of 1/2, or 0.50, since the two negati\e matches are not taken into consideration. A Pearson correlation coefficient (Siegel, 1956:195) was calculated based on the similarity coefficients of thaidid diet and radular morphology using SY'STAT (Wilkinson, 1986). This analysis was also performed on three subsets of the total number of pairwise comparisons. One ana- 1\ zed only of pairs of congeners; another analyzed only pairs of intergeners. In a third subset, all pairwise com- parisons with a dietary similarity of 0.00 were eliminated Irnm the analysis. In this study, the similarity coefficients for both radular morphology and diet were considered to fall into one of three arbitrarily set categories: high similarity (similar; coefficient > 0.62), median or ecjuivocal similarity (coef- ficient between 0.62 and 0.37), and low similarity (dis- similar; coefficient < 0.37). Relationships between sim- ilarities of radular morphology and diet thus fell into one of nine possible categories. S. p. Kool, 1987 Page 121 l^lil^ Figures 2-4. Nucella lapillus. 2. Sht-ll 1-22 x 3. Kadula 4. Kaciiidian, Figures 5-7. Nucella cmarginata. 5. Shell 1.44 x. 6. Radiila 7. Rachidian Figures 8-10. Concholepas concholepas. 8. Shell 0.90 x. 9. Radula 10. Rachidian. Figures 11-13. Nucclh lawclln.sa II. Shell 1.06 x. 12. Radula. 13. Rachidian. Page 122 THE NAUTILUS, Vol. 101, No. 3 RESULTS Figure 53 represents one of 13 equally parsimonious trees (consistency index = 0.56) produced using only radular data. Differences among trees were minor (see Discus- sion), and the number ne.xt to each bracket indicates the number of trees in which the bracketed portion appears. Generic assignment of the terminal ta.xa is based on pre- vious cladistic analyses of these taxa using only anatom- ical data (i.e.. exclusive of radula). The Pearson correlation coefficient between radular similarity and dietary similarity for all pairwise com- parisons was 0.05. This coefficient was 0.31 tor the anal- ysis of the subset consisting of the 11 pairwise compar- isons between congeneric species. It was —0.08 for the analysis of the subset consisting of all comparisons be- tween intergeners, and —0.12 using the data set from which comparisons with 0.00 dietary similarity were ex- cluded. No significant correlation (|p| > 0. 1) between radular morphologv- and diet was found in any of these analyses, indicating that there is little or no correlation between diet and radular morphology in these taxa. Similarity coefficients falling into the highest category (figure 54, Cell 1) for both radula and diet are present in only five out of the 120 pairwise comparisons. Two of these are comparisons between intergeners, the other three are comparisons between congeners. Another six congeneric and 13 intergeneric species pairs have radular similarities greater than 0.62 (figure 54, Cells 2, 3). Of these, three congeneric and 12 intergeneric species pairs have dissimilar diets, seven oi the latter having a dietary similarity of 0.00. Eighty-two percent of all pairwise comparisons between congeners have high radular sim- ilarities. Of these, only one-third have a high similarity in diet. A mere 15 of the 106 comparisons (14%) between intergeneric species have high radular similarit> . Onl\' two of these have a high similarity in diet. In six of the 11 comparisons between congeners, di- etary similarity coefficients were lower than radular sim- ilarity coefficients, while radulae were less similar than diets in four comparisons. Nucella lamellosa (figures 11- 13) and N. lapillus (figures 2-4) were exceptional in having identical radulae and diets. In Cell 1. three of the five comparisons that show high similarit\ in both radida and diet occur between con- generic species. Nucella lapillus, N. emarginata (figures 5-7), and N. lamellosa all feed on barnacles and mollusks, and their radulae are much alike. Stramonita haema- atuiua (figures 32-34) and Nucella emarginata both feed on mollusks and barnacles, and ha\e a radular similarity coefficient of 0.75. Similarly, Plicupurpiira patula (fig- ures 47-49) and Morula granulata (figures 44-46) have high similarities for both radula and diet. The three pairs of congeners with high radular simi- larity corresponding \\ ith low dietar\ similarity (Cell 3), are all in the genus Drupa. which has the highest di- versity in diet of all genera dealt with in this paper (see figure 53). Ten of the 12 intergeneric species pairs con- tain members of the genera Drupa, Morula, and Pur- pura, several having a dietary similarity coefficient of 0.00. The radula of Drupa grossularia (figures 23-25) is very similar to the radulae of Purpura harpa (0.75) (fig- ures 38-40) and P. panama (0.75) (figures 35-37), even though there is no overlap of diets. Drupella cornus (figures 26-28), which feeds exclusively on coral polyps, and Vexilla vexillum (figures 29-31), an urchin feeder, also have very similar radulae (0.83). Cell 5 contains the remaining two species comparisons between congeners: Drupa morum (figures 14-16) and Drupa grossularia. No two congeners were found to have coefficients for radular and dietary similarit> lower than 0.50. Representatives of Cell 6 show a moderate degree of resemblance in radular morphology, but little or no sim- ilarity in diet. This cell has the largest number of rep- resentatives of all nine cells. Cell 7 contains 10 representatives, indicating that low radular similarity can exist between species with highly similar diets. All members of Nucella, Purpura panama, and Plicopurpura patula feed on mollusks and barnacles, resulting in a 1.00 dietary similarit\ coefficient for all pairw ise comparisons between these taxa. However, the radular similarity coefficient between any Nucella species and either Purpura panama or Plicopurpura patula is only 0.33. Cell 9 contains examples of species pairs w ith dissim- Figures 11-16. Drupa amorum. 14. Shell 0.87 x, 15. Radula, Scale bar = 25 nm. 16. Rachidian Scale bar = 1.5 fim. Figures 17-19. Drupa ricinus. 17. Shell 1.17 x, 18. Radula. Scale bar = 25 fim. 19. Rachidian, Scale bar = 10 m"! Figures 20-22. Drupa ruhusidacus. 20. Shell 0.H9 x , 21. Radula, Scale bar = 25 fim 22. Rachidian, Scale bar = 10 urn. Figures 23-25. Drupa grossularia. 2:{. Shell 1,25 x, 21-. Radula, Scale bar = 20 ^im. 25. Rachidian, Scale bar = 10 nn\ Figures 26-2». Drupella cornu.'i. 26. Shell 1,1) x , 27. Radula, Scale bar = 0, 1 nun, 28. Rachidian, Scale bar = 10 ^ni. Figures 29-31. Vexilla vexillum. 29. Shell 1.08 x. .30. Radula, Scale bar = 2(1 urn. 31. Rachidian, Scale bar = 10 Mm Figures 32-34. Stramonita haemastoma. 32. Slid! 1,18 x. 33. Raihila. Scale liar = .'>(1 mi" 34. Rachidian, Scale bar = 15 nm. Figures 35-37. Purpura panama 35. Shell 0.66 x . 36. Radula. Scale bar = 100 urn. 37. Rachidian. Scale bar = 30 ^ni Figures 38-40. Purpura harpa. 38. .Shell 1.45 x 39. Radula Scale bar = 30 ^m. 40. Rachidian. Scale bar = 15 ^m Figures 41-43. Morula uva. 41. Shell 1.50 x. -42. Radula. Scale bar = 10 nm. 43. Rachidian Scale bar = 10 fim. Figures 44- 46. Morula granulata. 44. Shell 1,33 x. 45. Radula, Scale bar = 40 Mm, 46. Railndian, Scale bar = 30 Mm, Figures 47-49. Plicopurpura patula. 47. Shell 0,62 x. .48. Radula, Scale bar = 25 m"" 49. Ratliidian, Scale bar = 15 Mm, Figures 50-52. Muricanthus fulvescens. 50. Shell 0,37 x, 51. Radula Scale bar = 50 Mm 52. Rachidian, Scale bar = 20 ^im S. p. Kool, 198" Page 123 'A 17 •<■ '^ ^^ , / 20 -V- Page 124 THE NAUTILUS, Vol. 101, No. 3 § <^ 26 i 29 '^« V} o o (0 a a (13 J5 0 CO > 3 e ^ 0) C i_ CO CO CO ^ Q. ^ 2 S CO Figure 53. One of 13 equally parsimonious cladograms based on the raduiar characters in Table 1 Numbers below brackets indicate the number of trees in which the bracketed portion of the cladogram was identical. Prey eaten by each species is categorized into one or more groups and superimposed above each taxon. Solid circles indicate main food items, open circles indicate occasional prey. Mu. ful = Muriamlhus jiilvescens: C. con = Coiicholepas concholcpas; V. vex = Vcxilla vexillum; Dr. cor = Drupella cornus; PI. pat = Plicopurpura patula: N. lap = Nucella lapillm; N. lam = Nucella lamellosa; N. ema = \'ucella emarginata, M. gra = Morula granulata, M. uva = Morula uva: D rub = Drupa rubusidaeus, D mor = Drupa morum; D. ric = Drupa ricinus; D. gro = Drupa grossularia; S. hae = Stramonita haemastoma; P. pan = Purpura panama. P. har = Purpura harpa. ilar radulae and diets. Most of the comparisons in this cell involve at least one species v\ ith a highly specialized diet, such as Vexilla vexillun^, Drupella cornus, and Dru- pa grossularia (sipunculan-feeder). These have little or no dietary overlap w ith species of other genera, and their radulae are distinct. DISCUSSION Results indicate high congruence between anatonu and raduiar morphology and absence of correlation between raduiar inorphologv and diet. The absence of overall correlation, combined with the paucity of defendable cases for which convergence, perhaps due to diet, could be invoked, suggest that the role ol diet on evolution ol raduiar mor|)holog\ is insignificant. The cladogram in figure 53 is not completely con- gruent with the classification based on anatomical data, differing in the follow ing wa\ s. The genera Morula and Drupa, w hich appear to be paraphv letic based on raduiar tlata alone, are, although closeK related, each mono- phvletic based on anatomy (Kool, in preparation). The poK tomy at the base of the tree is less reflective of phy- logenetic relationship. Two poK chotomies are present in all 13 trees and occur in the same regions as in the figured tree. Additional raduiar characters ma\- provide higher resolution. Minor differences in resolution of the para- phv ly of Drupa and Morula and switches in the position of Plicopurpura patula (branching off before the Dru- pclla-Vcxilla lineagel and Morula granulata (branching off before the Nucella clade) account for the variation among the 13 trees. The high degree of congruence between a cladogram based on raduiar characters, and a generic di\ision ba.sed on anatomy shows that raduiar characters are valuable indicators of phylogenetic relationship in thaidid gastro- pods, assuming anatomical data truly reflect this rela- tionshi]) If dietar\ preference is superimposed on this S. p. Kool. 19S7 Page 127 cladograiii (or ain of tht- otlier trees mentioned above), there is no gradient in food items consistent with the phylogenetic arrangement based on radular morphology. Taxa feeding on moUusks and barnacles, for example, are dispersed over the entire tree, suggesting that no correlation exists between diet and radular morpholog\ . The Pearson correlation coefficients for the total num- ber of pairwise comparisons and for the subsets reveal no significant correlation between radular morphology and diet. .Although the correlation coefficient is non-sig- nificant lor all data sets, it is highest for tiie subset con- sisting of pairs of congeners. Similarity in radular mor- pholog\ in these pairs is most likely due to close phylogenetic affinities, but it is possible that diet may have had some influence on it. Diet may indeed aftect radular morpholog> . However, prior to invoking adapti\e scenarios and speculating about the influence of diet on the evolution of radular mor- pholog\ in thaidid and other gastropods, a purely de- scripti\e-correlati\e stud> between radular morphology and diet is necessar\ . If, for instance, se\eral different radular types can be used effectively on one food source, it could be In pothesized that diet may not exert sufficient selecti\e pressure to affect the e\ olution of radular mor- pholog) . The same conclusion may be drawn it one t\ pe of radula is used for a variety of food items. Diet and feeding habits have been linked with radular morpholog\- b\ a number of authors. N>bakken (1970: 316) found that the morphology of the radular teeth of three Conns species corresponds with their preying on amphinomids, an unusual prey item for Conns. Wu (1965b:102) has attributed the unique radular morphol- og\ of Drnpclla to its specialized food; coral poK ps. He also stated that ". . . radular patterns displaced b> . . . [Dnipa ricina (figures 17-19) and Morula granulata] . . . may possibly be associated with the feeding habits of each species" (1965a:226). Ta\lor (1976), in discussing variations in muricid radulae, suspected a correlation between morphology and diet, and indicated the need for further study. Fretter and Graham (1962:172) re- ported that radular morphology and diet are directK- correlated in prosobranchs. On many occasions authors have suggested a cause and effect relationship between diet and radular mor- phology. The mechanisms by which this occurs are never mentioned directly, but natural selection is implicitK understood as the process by which diet ma\' aftect rad- ular morpholog\. Solem (1974a:170) stated: "Evolution- ary changes in the patterns of cusp and support structure are obviously one of the prime ways in which snails specialize within local areas or exploit different levels of food resources." Powell (1964:230) in discussing similar radular patterns in several turrid subfamilies says that a change in turrid radulae has taken place ". . . no doubt as a direct response to predaceous feeding." Marshall (1978:54) pointed out that radular specialization occurs in Cerithiopsis. in response to different structural and textural attributes of its prey. Several authors have discussed convergence in radular DIET SIMILARITY 1-00 0.62 0.37 0.00 1.00 1 C = 3 2 C = 3 3 C = 3 < I = 2 I = 1 I = 12 ^"^ 0 fi9 I-H 4 c = o 5 C = 2 6 c = o Ph 1 = 15 1 = 8 I = 34 J 7 8 9 C = 0 c = o c = o < Cxi I = 9 I = 6 1 = 22 0.00 Figure 54. Distribution pattern ol pairwise comparisons of thaidid taxa on the basis of similarities in diets and radulae. Number in upper left corner of each block denotes cell number, C = pairs of congeners; I = pairs of intergeneric species. morphology and seem to attribute this to diet. Houbrick (1975:15, 1978:15) stated convergence as the reason for not giving much weight to radular characters in his stud- ies on the Cerithiacea. Convergence in radular mor- phology has also been discussed for Toxoglossa (Powell, 1964:230), herbi\orous landsnails (Solem, 1973; Breure & Gittenberger, 1982), and for Muricacea (Harasew%ch. 1984:24). Quantification of different relationships between rad- ular morpholog\ and diet, and quantification of conver- gence or parallelism in radular morpholog\ becomes pos- sible b\' di\iding all pairwise combinations into different categories. The distribution of congeneric and interge- neric species pairs (figure 54) can be analyzed and the possible role of diet in causing convergence addressed. Parallelism is herein considered part of convergence. A clear discussion on the difference between parallel evo- lution and convergence is given in Gosliner and Ghiselin (1984:258). Examples from Cell 1 suggest several possible expla- nations for radular similarity. Ancestral radular mor- pholog) ma\ have been conser\ed, as evolutionary change in radular morpholog\' is under phylogenetic constraint, or convergence has occurred. The similarit\' in the rad- ulae of the three S'ucella species is most likeK due to common descent; all three species feed on shelled mol- lusks (primarily mussels) and barnacles. It is unnecessar\- to invoke diet as the external selective agent for a radular morphologv especialK useful for these pre\ items. More- over, five other species, with different radular morphol- ogies, have the same diet (see figure 53). Convergence may explain similarit\ in radulae be- Page 128 THE NAUTILUS, Vol. 101, No. 3 tween intergeneric species found in Cell 1 (two pairs). And because dietary similarity is high between these taxa, diet could be invoked as the cause of these possible cases of convergence. Examples from other cells, how- ever, suggest that this is at best a rare occurrence. In Cell 3 tiiere are more than three times as many species pairs w ith high radular similarity and low dietary similarity than species with high similarity for both, as in Cell 1. It is also noteworthy that the number of pairs between intergeners is six times higher in Cell 3 than in Cell 1, which shows that if the radular siniilarit\ in in- tergeners in Cell 3 were due to convergence, diet can be ruled out as a selective agent, since diets are not similar (e.g., Driipella cornns. a coral feeder, and Vexilla vex- ilhim, an urchin feeder). Therefore, high similarity in radular morpholog\ is likely to be indicative of close phylogenetic affinities (conservation of radular charac- ters), or is at most due to convergence not driven b> diet. The homogeneous, horizontal distribution of conge- ners (Cells 1-3, figure 54) shows that radular morpholog\ is conserved, despite differences in dietary habits, and confutes diet as the selective force on divergence in rad- ular morphology. The low number of pairs of intergeners in Cell 1 suggests that diet is not a strong selective force for convergence in radular morphology. Only if dissim- ilarity in radulae of congeners matches dietary dissimi- larity, or if similarity in radulae of the intergeners match- es dietary similarity (Cell 1 ), is searching for causes other than genealogical relationship necessary. A comparison between Cells 1 and 7 shows that high dietary similarity corresponds more often with dissimi- larity in radulae than with similarity in radulae. This applies to pairs of intergeners only, as radular similarit\ is consistently high between congeners, regardless of di- etary similarity. The high number of representatives in Cell 9 indicates that low radular similarity often corresponds with low dietary similarity. There is no need, however, to invoke diet to explain divergence in radular morphology amongst intergeners in this cell, because radular dissimilarity can be ascribed simply to general phylogenetic divergence. Examination of individual cases of the 120 pairwise comparisons sheds light on why diet may not play an important role in the evolution of radular morphology. There are many examples showing that radulae of dif- ferent morphologies are used for similar food items. This information is most easily derived from figure 53, which shows that mollusks are main food items for 11 of 16 species. Other examples suggest that similar radulae can be used for different food items. This occurs among species [e.g.. Drupti rubusidaeus (figures 20-22) ami Drupa mo- rum, Vexilla vexillttm and Dntpella cornusl and within species such as the "generalist" Drupa ricinus, which feeds on mollusks, small crustaceans, polychaetes, bar- nacles, sponges, and hdlotluirians (figure 53; table 3). The two pairs of congeners in Cell 5 indicate that although radular morpholog\ may evolve at different rates among congeners, similarity in diet cannot be in- \ oked as a cause. The above findings suggest that radular characters are evolutionarily conservative in thaidid gastropods and dis- pel the need to invoke an adaptive scenario to explain radular morphology. If different radulae can be used for different food items, and if a similar (or one and the same) radula can be used for different food items, then radular morphology is not likeK' to be under high selec- tive pressure from diet. If diet does not exert great se- lective pressure on radular morphology in any particular species, it cannot be the causal agent for convergence in radular morphology between those species. It is possible that the highK unusual radular mor- phology of, for example, Drupelta cornus is related to its food type (coral polyps). However, the radula of this species is very similar to that of Vexilla vexilhim. which feeds on sea urchins. Further studies of diet and radular morphology of other species of Drupella sensu stricto and Vexilla sensu stricto will reveal if these unusual morphologies alv\ ays correspond with the same diet. Per- haps other Drupella species with t\pical Drupelta rad- ulae feed on food items other than corals. I postulate that unique radular morphology is not necessarily the direct result of adaptation to a unique diet, but rather of rel- ati\el\ rapid accumulation of changes in the genome of the (ancestral) species. In such a case, the radula nia\- be "pre-adapted " to coral feeding. Although different taxa may have similar diets, feed- ing modes can differ substantially. Both Drupella cornus and coralliophilids, for example, feed on coral polyps (Robertson, 1970:49; Brawley & Adey, 1982), although coralliophilids lack radulae (Thiele, 1929:300; Robertson 1970:47). Drupella most likeK scrapes the polyp, after liquif\ing it extracorporealh (Fankboner, 1970) whereas Coralliophila feeds suctorialK (Ward, 1965:460). As more data on feeding modes become available, modes of feed- ing and application of the radula to the substrate may be added as a fourth \ariable, along with radular mor- phology, diet, and ph\ logenetic affinit> . In order to de- tect correspondence between radulae and feeding modes, thaidids could then perhaps be divided into those that tear off large chunks of flesh, those that rasp off fine pieces of tissue, and those that bore through shells or barnacles prior to feeding. A similar categorization was used by Solem (1974b), who divided carnivorous land snails into "slicers", "stabbers", and those which slice and stab. Shimek and Kohn ( 1981 ) di\ ided turrid radulae into six comparable functional groups. Alterations in diet, due to changes in relative prey abundancy, are discussed for thaidids in West (1986) and Murdoch (1969). These examples of switching prey pro- \ide more e\idence for the generalized function of thai- did radulae, and suggest that thaidid radular morphology has not evolved to accommodate any particular feeding mode or prey, and is not steered by adaptive processes. Some of the radical changes in feeding modes or diets ma\ correlate v\ ith a species' age and size. For example, juveniles of Muricanthus nigritus (Philippi, 1845) prey mainly upon barnacles, whereas adults prey mainK' on gastropods (Paine, 1966:22). Brand and Lipps (1982) re- S. p. Kool, 1987 Page 129 porteil tliat jiueiiiles of the opistliobrancli Fhilene alata prefer to feed on foraminifera, while adults prey upon small bivalves. Perhaps a smaller and narrower radula in a juvenile may be more suited for feeding on minute prey items than the adult radula with wider spaces be- tween teeth cusps and denticles. It may thus be that spacing between different teetfi, cusps, and denticles is of importance in food manipulation and food choice. Scaling should be taken into consideration in future stud- ies of radular form and function to examine if distance between cusps and denticles influences food choice (or vice versa). It may also be that ontogenetic (morphological) changes in radular morpholog)' occur, which correspond with a switch in food items. Plaziat (1977:37) found such a cor- respondence in Terebralia palustris (Linne, 1767); ju- veniles of this species feed on micro-flora, but the adults eat only mangrove leaves. The radula in the adults is radically different from that in juveniles. However, no such ontogenetic changes combined with changes in di- etary habits ha\e been reported for thaidids. More detailed studies on how radulae interact with prey substrate are essential to determine which teeth, cusps, and denticles are mostK' involved in the actual scraping, slicing, or boring processes. Information on the mechanics of feeding may reveal if certain radular char- acters are more likely to be under dietar\' constraint than others; a topic w hich cannot be addressed at this time. It is possible that several different radular morphologies may be suitable for one food type if applied to the sub- strate differently. Hickman (1984) and Hickman and Morris (1985) have shown that the interpla\ (sequence and timing) between the different teeth in some archaeo- gastropods is rather complicated. In rachiglossates the possibilities of interaction are fewer because of a rela- tively simple tooth configuration (only one rachidian flanked on both sides b},- one lateral tooth). In the Muricacea (and Naticidae), secretions of a bor- ing organ aid in the mechanical penetration of prev prior to feeding (Carriker et al, 1963; Carriker et al.'. 1978; Carriker, 1981). These secretions facilitate penetration through CaCO, layers of shells and barnacles and may have similar effects on other outer body coverings in different prey. This may mean that a radula of general morphology is suitable for boring and feeding. Clearly, the interaction between the mechanical and biochemical manipulations in muricid feeding beluuiour deserves more detailed attention. Sexual dimorphism in radulae has been reported for several thaidid genera: Nassa Roding, 1798 (Maes, 1966), Driipella (Arakawa, 1957; Fujioka, 1982), Morula (Fu- jioka, 1984), and Cronia H. Adams & A. .Adams, 1853 (Fujioka, 1984). No statements can be made on degree of se.xual dimorphism in the species studied herein, be- cause radulae were randomly dissected, in some cases, from onl\ two individuals. Small differences, as reported in the literature for the above genera, would not sub- stantially alter the character coding used here, and the results of this paper would not change. It would be in- teresting to assess diet of both sexes in species displaying sexual dimorphism. An identical diet for both sexes would present additional evidence of different radulae being suitable for one food type (Cell 7). Another aspect that needs more detailed stud\ is geo- graphical variation in radular morphologv and its pos- sible correspondence with regional differences in prey availabilit\-. Dietar\- habits of individuals from different localities should he assessed, their radulae examined, and relationship between variation in diet and radular mor- phology studied. For example, Taylor (1983:308) found that Drupa rubusidaeus from Addu Atoll feeds mainly on demosponges, whereas specimens from other localities in the Indo-Pacific are polychaete-feeders. Conclusions drawn in this paper predict that the radulae of these populations are similar despite dietary differences. ACKNOWLEDGEMENTS I wish to express m\ gratitude to Drs. Richard S. Hou- brick, Robert Hershler, and M. G. Harasewych, De- partment of Invertebrate Zoology, National Museum of Natural Histor\, Smithsonian Institution, for assistance, comments, and suggestions in preparation of this paper, and for critically reviewing it. Drs. Robert Hershler and Lee-Ann Hayek of the National Museum of Natural His- tory shared their insights on the statistical analyses. I further acknowledge the NMNH SEM staff and Dr. Mary F. Mickevicli, Associate, Maryland Center for Systematic Entomolog) , Lhiiversity of Maryland, and of the Smith- sonian Institution, and the Systematic Entomology Lab- oratory, U.S. Department of Agriculture, for access to PHYSYS. 1 am further indebted to Dr Mary E. Rice, Chief Scientist, and her staff, of the Smithsonian Marine Station, Link Port. This is Contribution No. 191 of the Smithsonian Marine Station, Link Port, Florida. I grate- fully acknowledge the support of the Smithsonian's Ca- ribbean Coral Reef Ecosvstems Program. This is Con- tribution No. 208 Reef and Mangrove Stud> , Belize, partly supported by the Exxon Corporation. Mr. J. Michael Brittsan of the Marine Systems Laboratory, Smithsonian Institution, kindly provided specimens of Nucella lapil- liis. I thank Dr. Lucius Eldredge of the Marine Labo- ratory of the University of Guam, Agana, Guam, Dr. Michael Hadfield of the Pacific Biomedical Marine Lab- oratory, Universit\ of Hawaii, Honolulu, Hawaii, and Dr. Winston Ponder of the .Australian Museum, S>dne\ , for use of laboratory equipment and supplies. Dr. Diana Lipscomb of The George Washington University shared her insights in phylogenetic svstematics. This paper is part of a Ph.D. dissertation. 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THE NAUTILUS 101(3):133-139, 1987 Page 133 Phreatodrobia coronae, a New Species of Cavesnail from Soutfiwestern Texas Robert Hershler Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560. ISA Glenn Longley Eduards Acjuifer Research and Data Center Southwest Texas State L'nisersitv San Marcos, TX 78666-4615, USA ABSTRACT Phreatodrobia coronae new species, a blind and unpigmented ca\esnail, was collected from spring oritices at two sites in or near Del Rio, \'al \'erde Count), Texas, This new species is separable from other known congeners b\' its free and largely uncoiled apex and has affinities w ith similar-shelled forms oc- curring in Balcones Fault Zone and Hill Country to the east. INTRODUCTION Edv\ards limestone and associated aquifers in south- western Texas support a large phreatic fauna of about 50 species (Longley, 1981; Hershler and Longley, 1986a). Subterranean aquatic conditions in the region \ar\ from air-exposed to deep artesian, with habitat size ranging from interstitial pores in limestone matrix to large so- lution caverns. Structural complexity of this phreatic sys- tem has facilitated differentiation of taxa, with the most speciose elements consisting of amphipod crustaceans (Holsinger and Longley, 1980, and references cited therein) and cavesnails of the family H\ drobiidae, com- prising seven species of Phreatodrobia Hershler and Longley, 1986a, as well as three monotypic genera (Hershler and Longley, 1986a, b). Field work by the senior author during 1984 included collection of phreatic organisms from two springs in vi- cinit\' of Del Rio, Val Verde County (figures 1-3). Among the diverse fauna discovered was a highly distinctive blind cavesnail that we describe herein as a new species of Phreatodrobia. SYSTEMATICS Phreatodrobia coronae Hershler new species Del Rio cavesnail (figures 4-21; table 1) Materials examined: Holotype (figure 6; USNM 859219), a dry shell of 1.27 mm width, from unnamed spring on E side of Devils River in canyon just downDow from Slaughter Bend, Val Verde County, Texas, Satan Canyon (1972) 1: 24000, ca. 5.1 km NW of SE corner of quad- rangle, elevation ca. 342 m, R. Hershler and S. Corona, 17 IX 1984. Additional series from type locality include 7 (dry shells) paratypes (USNM 859154, collected by S. Corona, 26 VIII 1986), and a lot split into dried (10) and alcohol (13) specimens (USNM 859156, collected bv S. Corona, 1-8 IX 1986). Single series (USNM 859164^ 13 empty shells and 2 alcohol specimens) also from small spring (San Felipe Springs) on W side of San Felipe Creek bv #2 hole on San Felipe Coinitr\ Club N of HW 90 in Del Rio, Val Verde, Texas, Del Rio SW (1972) 1: 24000, ca. 1.1 km SW of NE corner of quadrangle, elexation ca. 290 m, R. Hershler, 14 IX 1984. Diagnosis: .\ small-sized species with near-planispiral to low-trochoid shell having loosely coiled, protruding apex. Teleoconch sculpture consisting of 10-20 collabral varices or costae and 30-40 strong spiral lines. Opercular peg well-developed. Ctenidium absent. Central tooth of radula with single pair of basal cusps. Intestinal coil in pallial roof complex. Description: Shell measurements and counts for 7 para- types (sexes mixed) are in table 1. Shell (figures 4-13) transparent, colorless, about a millimeter wide with 3 tubular, moderately expanding whorls. Protoconch whorls, 1.25. Periostracum light brown. Sutures deeply impressed. Translation rate (and therefore shell height) variable (ranging from ca. 1.0 to 2.0), yielding diversity in shell form (figures 6-9). First V4 whorl of protoconch (figure 10) free and nearly uncoiled, producing horn- like apex strongly contrasting with teleoconch shape. Ap- erture ca. 30-40° oblique to coiling axis with adapical portion extended forward, near-circular in cross section, moderately flared all around, often slightly fluted above and below. Inner lip well-thickened and either separate from or narrowK adnate to bod\ w horl abo\ e. L mbilicus broadly open (figure 5). Protoconch w ith wrinkled pits (figures 4, 12, 13). Strong spiral lines beginning at end of protoconch, with costae beginning 0.5-1.0 w horl later. Lines are uniformly spaced all around exposed portions of whorls and cross collabral sculpture (figure 11). The Page 134 THE NAUTILUS, Vol. 101, No. 3 Figure I. Map of \'al Verde County, Texas, showing drainage and collecting sites (filled circles). Adapted from General High- way Map, Val Verde Count) , Texas. latter varying from low varices to lamelliform costae, typically slightly curved forward. Operculum (figures 14-16) amber, paucispiral, near- circular, with 4 whorls and strong peg located sub-cen- trally on inner (ventral) surface. Operculum and peg corneous. Peg height several times thickness of remaining operculum (figure 16). Pedal attachment scar elliptical. Radular formula (from figures 17-20): centrals, 6(7)- l-(7)6/l-l; laterals, 5-1-6; inner marginals, 17-18; outer marginals, 18. Central teeth (figure 17) broadly trape- zoidal. Cusps on all teeth elongate, often dagger-like. Animal without eyespots and melanic pigment. Scat- tered black (internal) granules on dorsal stomach and ventral style sac. Pallial cavity longer than wide, with majority of roof occupied by intestine (In, figure 21). Osphradium (Os) small, positioned anterior to pallial intestine near mantle collar. Stomach slightly longer than st\ le sac. Pallial intestine looping twice, with first loop inside of second; long axes of loops parallel to pallial cavity length (figure 21 ). Anus located along columellar edge near mantle collar. Testis (Ts, figure 21 ) a simple sac filling much of diges- tive gland posterior to stomach. Seminal vesicle (Sv) con- Figure 2. Photograph (8 IX 1986) of collecting site at unnamed spring on E side of Devils Hiver just downflow from Slaughler Bend, \ al Verde C:ounty, Texas, Arrow mdicates location of spring source. Figure 3. Photograph (8 IX 1986) of collecting site at San Felipe Springs on VV side of San Felipe Creek on San Felipe Country Club, Del Rio, Val Verde C^ounty, Texas. Arrow indicates location of spring source. R. Hershler and G. Longley, 1987 Page 135 Figure 4-. Photograph (SEN!) of apical shell aspect of Phreatodrobia coronac new species from unnamed spring on E side of De\ils River just downflow from Slaughter Bend, Val Verde County, Te.xas, Scale bar = 0.5 mm. Figure 5. Photograph (SEM) of umbihcal shell aspect of P. coronae. Locality and scale as above. Figure 6. Photograph (SEM) of holotype of P. coronae new species. Locality and scale as above. Figure 7. Photograph (SEM) of shell of P. coronae new species. Locality and scale as above. Figure 8. Photograph (SEM) of shell of P. coronae from San Felipe Springs, Del Rio, \'al Verde County, Texas. Scale as above. Figure 9. Photograph (SEM) of shell of P. coronae. Locality as above. Scale as above. sisting of a few thickened coils anterior to testis and abutting against prostate gland. Vas efferens absent. Pros- tate gland (Pr) \ello\\ -colored, elongate (twice as long as wide), almost totalK posterior to pallial cavity. Pos- terior vas deferens entering near posterior tip of gland; anterior vas deferens (Vd2) exiting from anterior tip and travelling straight path in pallia! cavity floor. Penis (not figured) simple, coiling on right side of "neck." Filament ca. ''3 penis length, tapering distalK \'as deferens with- out undulations in penis. Description of female anatomv limited due to lack of sufficient material. Ovary a white-colored, simple sac Page 136 THE NAUTILUS, Vol. 101, No. 3 Figure 10. Photograph (SEM) of juvenile shell of P. coronae from unnamed spring on E side of Devils River just below Slaughter Bend, Val Verde County, Texas. Scale bar = 240 Mm. Figure 11. Photograph (SEM) showing teleoconch sculpture of P. coronae. Locality as above. Scale bar = 23 Mm. Figure 12. Photograph (SEM) of apical shell aspect of P. coronae from San Felipe Springs, Del Rio, Val Verde County, Texas. Scale bar = 150 ^m. Figure 13. Photograph (SEM) showing shell apex of P. coronae. Locality as above. Scale bar = 200 nm. filling ca. 20% of hocK length. Anterior end of pallial oviduct simple, with broad, slit-like, terminal opening. Bursa copulalrix largely posterior to albumen gland. Seminal receptacle not seen; sperm storage perhaps oc- curring in single, highly swollen oviduct coil located just proximal to opening into albumen gland. Variation: Differentiation among the two known pop- ulations is evident, as shells from spring on De\ ils River vary from near-planispiral to low-trochoid (shell height, width, 45-85%) and typically have well-developed and numerous collabral costae, whereas examples from San Felipe Springs are usually low-trochoid (shell height/ width, 80-100%), with collabral sculpture weakly de- veloped (figures 6-9 show extremes of shell form). It is clear that shell form and sculpture pattern overlap in these populations and we therefore choose to consider them as a single species. Etymology: Named in honor of Mrs. Susannah J. Corona and famil) for their assistance in obtaining material of this species from the type locality. Comparisons: Phreatodrohia coronae is separable from all other congeners b\ its unique protoconch. While re- sembling P. imitata Hershler and Longle\, 1986a, in R Hershler and G. Longley, 1987 Page 137 Figure 14. Photograph (SEM) of ventral aspect ot operculum (showing peg and muscle attachment scar) of P. coronae from unnamed spring on E side of Devils River just below Slaughter Bend, Val Verde County, Texas. Scale bar = 1.50 ^lm. Figure 15. Photograph (SEM) of ventral aspect of operculum of P. coronae. Locality and scale as above. Figure 16. Photograph (SEM) of lateral aspect of operculum (showing height of peg) of P. coronae. Locality as above. Scale bar = 150 /xm. terms of teleoconch sculpture pattern, P. coronae is clear- ly allied to P. nugax (Pilsbry and Ferriss, 1906) and P. micra (Pilsbry and Ferriss, 1906) from Balcones Fault Zone and Hill Country (to the east) on basis of simple, near-planispiral to low-trochoid shells and similarities in radular and female reproductive morphology (see Hershler & Longley, 1986a). The novelty described herein is distinguished from both of the above by well-devel- oped teleoconch sculpture (collabral costae known from single population of P. nugax, Hershler & Longley, 1986a: fig. 4U), complex pallial intestine, and absence of gill filaments; and further separable from P. nugax by small- er size and more highly developed opercular peg. Discussion: Both sites (figures 2, 3; latter also shown in Brune, 1975: fig. 6) are moderate-sized rheocrenes having single, discrete orifices that were netted (for method, see Hershler & Longley, 1986a: 130-131) to collect phreatic biota. Nets could not be tightly fitted into the rather large orifice at San Felipe Springs and small size of re- sulting samples is probably due to sweeping of specimens out of net or feeding b\ fishes. With current decreased flow of Goodenough and Comal Springs, San Felipe Table 1. Measurements (mm) and counts from seven shells (paratypes) of Phreatodrobia coronae new species from un- named spring on E side of Devils River just below Slaughter Bend, Val Verde Countv, Texas. Standard Character Mean Range deviation Number of whorls 3.0 Shell height 0.67 0.53-0.81 0.09 Shell w idth 1.11 1.04-1.17 0.05 Bod\ whorl length 0.55 0.42-0.66 0.08 Bodv whorl width 0.81 0.73-0.89 0.05 ,\perture length/ width LOl 0.85-1.22 0.13 Number of collabral varices 1671 14.0-21,0 .1 ~ Springs, collectively discharging ca. 70-100 feet^/sec, now rank as second largest in the state and may be increasing due to local recharge from Amistad Reservoir (Brune, 1975). Water source for these springs is George- town limestone of Edwards Aquifer (Brune, 1975). The unnamed spring on Devils River is periodically sub- Page 138 THE NAUTILUS, Vol. 101, No. 3 Figure 17. Photograph (SEM) of central radular teeth of P. coronae from unnamed spring on E side of Devils River just below Slaughter Bend. Scale bar = 3.8 urn. Figure 18. Photograph (SEM) of lateral (above) and inner marginal (below) radular teeth of P. coronae. Locality as above. Scale bar = 2.7 fiiw Figure 19. Photograph (SEM) of lateral (3) and inner marginal (2) radular teeth of P. coronae. Locality as above. Scale bar = 3.8 fim. Figure 20. Photcigraph (SEM) of outer marginal radular tooth of P. coronae. Locality as above. Scale bar = 1.76 ixm. R. Hershler and G, Longley, 19S" Page 139 merged when Amistad Reservoir crests above conser- vation level (340 4 m)^ Discharge ol this spring is ca. 2- 4 feetVsec and water source is likely the same as that for nearby Slaughter Bend springs: Georgetown lime- stone (Brune, 1975). Collections from San Felipe Springs included an ad- ditional undescribed cavesnail belonging to H\ drobiidae: Littoriilininae and having affinities with Balconorbis Hershler and Longle\ , 1986a, from Uvalde Count\ . This was also collected from the unnamed spring on Devils River as were blind and unpigmented amphipod crus- taceans, asellid and cirolanid isopods, and copepods. In- cluded among the amphipods are forms having affinities with taxa from Comal, Kendall, and Hays counties to the east (J. R. Holsinger, letter to senior author dated 13 IX 1986). ACKNOWLEDGEMENTS We thank the National Park Service at Amistad National Recreation Area (especialK staff at Rough Canyon) and San Felipe Country Club for permission to sample springs. The former also provided transportation to collecting sites on several occasions. The study could not have been completed without the field assistance of Mrs. S. Corona. Fieldwork of the senior author was partK funded by United States Fish and Wildlife Service (Contract No. 14-16-0002-84-228, Amendment No. 1). LITERATURE CITED Figure 21. Dorsal aspect (minus head/foot) of male P. coronae from unnamed spring on E side of Devils River just below Slaughter Bend, Val Verde County, Te.xas. Dg = digestive gland; In = intestine; Ki = kidney; Os = osphradium; Pr = prostate; Sts = style sac; Sv = seminal vesicle; Ts = testis; Vd2 = anterior vas deferens. Brune, G. 197.5. Major and historical springs of Texas. Texas Water Development Board Report 189:94 p. Hershler, R and G. Longley. 19S6a Phreatic h\drobiids (Gas- tropoda: Prosobranchia) from the Edwards (Balcones Fault Zone) Aquifer region, south-central Texas. Malacologia 27: 127-172. Hershler, R. and G. Longley. 1986b Hadoceras taylori. a new genus and species of phreatic Hydrobiidae (Gastro- poda: Rissoacea) from south-central Texas. Proceedings of the Biological Societ\ of Washington 99:121-1.36. Holsinger, J R and G. Longley 1980. The subterranean amphipod crustacean fauna of an artesian well in Texas. Smithsonian Contributions to Zoolog\ 308:62 p. Longley, G. 1981. The Edwards .\ciuifer: earth's most diverse groundwater ecosystem? International Journal of Speleol- ogy 11:123-128. THE NAUTILUS 10i(3):140-142, 1987 Page 140 Morphological Anomalies in the Shell of Natural Populations of Helisoma trivolvis Say (Gastropoda: Planorbidae) Eva Pip Department of Biology Uni\ersit\ of Winnipeg Winnipeg, Manitoba R3B 2E9 Canada ABSTRACT A total of 157 natural populations of Helisoma trivolvis Say in central and western North America were examined for the occurrence of whorl deflection. The anomaly was observed significantly more frequently than expected due to chance in ponds, on fine bottom sediments, and in waters with low dis- solved organic matter and low combined nitrate and nitrite concentrations. Certain habitat characteristics may enhance the occurrence of this anomaly, but it is not known w hether genetic factors or ecologically induced effects are responsible. INTRODUCTION Recently Gomez et al. (1986) reported the incidence of varying frequencies of phenot\pic anomalies in a num- ber of natural populations of Biomphalaria globrala Sa\ , 1818 in the Dominican Republic. The deformity most frequently observed consisted of whorl deflection and overlapping, resulting in shells that were not entirely planispiral. Genetic factors were strongly suspected as the responsible agents. The present paper reports the incidence of a similar anomaly in natural populations of another planorbid, Helisoma trivolvis Say, 1816 (nomenclature according to Clarke, 1981), an ultrasinistral species. Distribution of the occurrence of the anomaly was studied in central and western Nortfi America with respect to type of water body, type of bottom substrate, eight water chemistry parameters, and plant and snail species richness of the communities in which the jjlanorbids were foimd. MATERIALS AND METHODS Living and freshly dead individuals of H. trivolvis were examined at 157 sites located in British (>)lumbia. Al- berta, Saskatchewan, Manitoba, Ontario, North Dakota, and Minnesota. All sites contained water year-round Most sites were visited once during 1972-85. A surface water sample was collected at 127 sites, placed on ice and frozen within a maximum of 48 hr after collection. Total dissolved solids, total alkalinit\'. chloride, sulphate, molybdenum reactive phosphorus (MRP), combined nitrate and nitrite, and dissolved or- ganic matter (DOM) were determined using methods recommended by the American Public Health Associa- tion (1971). The pH was determined directly in the field using a portable pH meter. Ten of the sites were sampled a number of different times; for these, extreme water chemistry values were used for statistical anaKsis. Species richness of gastropod and macrophv te com- munities was assessed during a search time of 1 hr at each site, by wading or by dredging with a rake from a small boat. In statistical analyses, sites at which the anomaK was present were compared with those at w hich it appeared to be absent (henceforth designated as found and re- maining sites, respectiveK ). Frequency \alues of the in- cidence within individual populations were not used be- cause of the widely vary ing numbers of indi\ iduals that could be obtained for examination at the different sites. Values of p < 0.05 were considered significant for all statistical tests. RESULTS The most frequently observed anomaly in H. trivolvis consisted of deflection of the w horl away from the plane of coiling, accompanied by uneven partial o\erlap onto the preceding whorl (figures 1-4). In some specimens deflections were repeated a number of times during growth. The incidence of deflection at various sites ranged from 0 to 100/c of the shells examined. The anomaly was observed at 44 of the 157 sites investigated (28rc), and was seen in all regions of the study area, indicating that it was quite widespread. However it appeared to be noticeably more frequent west of the Precambrian Shield boundary. Types of water bodies were classified as ponds (< 10 ha), lakes (> 10 ha), rivers (> 2 m deep), and creeks (< 2 m deep). The frequencies of the w ater body types were compared for iound and remaining sites using 2x4 chi- square tests. The results indicated a significant difference in overall distribution (chi-.s(]uare = 10.3, p = 0.016, E. Pip, 198- Page 141 df = 3). Ponds showed the greatest proportion of found to remaining sites (0.71, N = 60), followed In combined lotic habitats (0,22, N = 22) and lakes (0.18, N = 45). Student-Newman-Keuls multiple comparison tests indi- cated that the difference between ponds and all other water body t>pes was significant. Bottom substrate was classified according to the pre- dominant type at each site. Frequencies of substrate t} pes were compared at found and remaining sites using chi- square tests. Overall differences were marginally signif- icant (chi-square = 13.7, p = 0.05, df = 7). Sand and clay showed the highest proportions of found to remain- ing sites (0.75, N = 28, and 0.61, N = 37, respectively), followed by silt (0.50, N = 12), highly organic sediments (0.33, N = 16), and gravel (0.04, N = 24). Samples were too small for shale, limestone, and granitic bedrock for adequate comparison. The Student-Newman-Keuls pro- cedure indicated that incidence of the anomaly was sig- nificantly lower on gravel than on either sand or clay; other differences were not significant. Water chemistr> was examined at found and remain- ing sites using unpaired t-tests, provided that the results of F-tests were not significant; otherwise nonparametric comparisons were made using Kolmogorov-Smirno\' two- sample tests. Mean values were higher at found than at remaining sites for total dissolved solids, total alkalinity, chloride, and MRP (table 1), but these difterences were not significant because of the variability of the values in both groups. Thus, while the mean \alue of chloride was almost 10 times greater at found than at remaining sites, the degree of overlap between the two groups rendered this difference insignificant. However, combined nitrate and nitrite, and DOM showed significantly lower mean values at found than at remaining sites. Species richness at found and at remaining sites was not significantK' different for macrophyte communities (Kolmogorov-Smirnov Z = 0.77, p = 0.60) or for gastro- pod communities (t = 0.42, p = 0.68). DISCUSSION Whorl deflection and open coiling has been noted in other planorbid genera (Meier-Brook, 1983), as well as in H. Figures 1-4. L'pper views of normal (1) and abnormal (2-4) specimens of Helisoma trivolvis. 1. Marsh ditch, Delta .Marsh, Lake Manitoba, Manitoba (2.5. .5 mm), 2. Pond, 9.6 km east of Richer, Manitoba (22.0 mm), 3. Pembina River at Hwy, No, 34, Manitoba (22.5 mm). 4. First \'ermilion Lake, near Ranff, Alberta (24.0 mm). trivolvis and related species (Baker, 1936, 1945). In the present study whorl deflection was encountered in pop- ulations found over the entire geographic area studied, but was relatively infrequent in eastern Manitoba, On- tario, and Minnesota. The anomaly was most often en- countered where DOM and combined nitrate and nitrite values were comparatively low; other inorganic param- eters (e.\cept sulphate and pH) were also somewhat higher at many, but not all, sites where the abnormalitv was present. These characteristics (e.xcept low nitrate-nitrite) coincided with areas west of the Precambrian Shield boundary. However, this abnormality was correspond- ingly rare where waters with higher DOM and lower inorganic values did occur west of the Shield. While Gomez et al, (1986) noted that deformed Biom- phalaria glabrata were often associated with e.xcessive calcareous deposits on the shell, in the present study such differences were not evident between normal and de- formed shells of H. trivolvis within the same population. Table 1. Mean water chemistrs values at sites where deformed shells were and were not obsersed, X'alues of t or Kolmogorov- Smirno\ Z are gi\'en as appropriate. Parameter Normal Def ormed X SE N .f SE N Significance 8.1 0.1 97 8.1 0.2 40 t = 0,11, p = 0,92 372 58 94 395 65 40 Z = 1,00. p = 0.27 143 11 96 176 17 40 t = 1,66, p = 0.10 8 0 95 71 25 38 Z = 0.96, p = 0.32 38 6 96 39 12 40 Z = 0.50, p = 0,97 1.37 0.11 96 0 94 0.12 40 Z = 1 43, p = 0.03* 3.18 0.34 96 4,03 0,75 40 Z = 0,85, p = 0.46 0 35 0,02 95 0,22 0,02 34 Z = 1.77, p = 0,004* pH Total dissolved solids, mg/liter Total alkalinity, mg/liter CaCO, Chloride, mg liter Sulphate, mg/liter Combined nitrate and nitrite, mg, hter Molybdenum reactive phosphorus, mg/liter Dissolved organic matter, absorbance (acidified) at 275 nm ' Significant difference. Page 142 THE NAUTILUS, Vol. 101, No. 3 However deformed shells were usually present in thick- shelled populations; anomalous individuals were seldom seen in calcium-poor, DOM-rich Shield waters, where shells were thin and contained a high proportion of or- ganic material. The significant tendenc\ for the deformit\ to occur in ponds ma\ have been associated with the more ex- treme conditions that are often encountered in small water bodies, for example higher inorganic concentra- tions, greater seasonal environmental fluctuations in water chemistry and temperature, and elevated infection rates by various pathogenic organisms. Finer sediments were also significantly more frequently associated with this anomaK than were coarser materials, perhaps as a result of the greater frecjuency of fine sediments in quiet ponds. If genetic factors contribute towards the anomaly in H. trivolvis. the higher frquencies of this anomaly in ponds may be associated with a greater likelihood of self- fertilization (e.g., Meier-Brook, 1983) and inbreeding in small, genetically limited populations. It is also possible that gene expression or penetrance may be modified or enhanced by particular environmental factors. If genetic factors are not in\olved, it ma\- be an ecologicalK in- duced effect. Other factors, such as infection with par- asites, pollution, thermal stress, etc. cannot be ruled out, since these are also more likely to be pronounced in small water bodies. Clearly much additional study is required. LITERATURE CITED American Public Health .Association. 1971. Standard methods for the examination of water and wastewater, .•\merican Public Health .Association, New York, 874 p. Baker, F. C. 1936. The freshwater mollusc Helisoma cor- pulentum and its relatives in Canada. National Museum of Canada Bulletin No. 79:1-33. Baker, F. C. 1945. The molluscan famik Planorbidae. Uni- versity of Illinois Press, Urbana, IL, 519 p Clarke, A. H. 1981. The freshwater molluscs of Canada. Na- tional Museums of Canada, Ottawa, 446 p. Gomez, J., M. X'argas, and E A. Malek. 1986. Morphological anomalies in the shell of field-collected Biomphalaria gla- brata (Say, 1818). The Nautilus 100:53-55. Meier-Brook, C. 1983. Taxonomic studies on Gijraulus (Gas- tropoda— Planorbidae). Malacologia 24:1-113. THE NAUTILUS 101(3):14;3-150, 1987 Page 143 Prehistoric Freshwater Mussel Assemblages of the Mississippi River in Southwestern Wisconsin James L. Theler L'niversitv of Wisconsin-La Crosse La Crosse, WI 54601, USA ABSTRACT Archaeological excavations at aboriginal sites adjacent to the lipper Mississippi River (L'MR) in southwestern Wisconsin pro- duced a series of freshwater mussel (naiad) assemblages that contained more than 29,000 valves of 28 mussel species. These subfossil mussel valves are the remains of mollusks harvested as a food source by prehistoric peoples between circa AD. 1 and A.D. 1000. Taken together, the aboriginal assemblages provide an appro.ximation of the regions main stem UMR naiad communities during the latter part of the prehistoric era. A quantitative comparison of the subfossil collection with modern mussel surve\ data documents dramatic changes in the species composition of molluscan communities following habitat deg- radation of the UMR associated with Euro.\merican settlement. INTRODUCTION The na\igation pools of the present-da\ Upper Missis- sippi River (UMR) were created b\ a series of locks and dams built b\' the U.S. Army Corps of Engineers during the 1930's and 1940's (Rasmussen, 1979:4). Although a number of recent studies have focused on freshwater mussels (naiades) in the UMR {e.g., Havlik & Stansberv, 1978; Mathiak, 1979; Perry, 1979; Fuller, 1980; Thiel, 1981; Duncan & Thiel, 1983; Havlik. 1983), there are few pre-lock and dam, taxon specific reports of naiad distribution prior to significant habitat modification and the large scale commercial harvest that severely depleted mussel populations during the late 19th and early 20th century. Some early reports on UMR freshwater mussels (Pratt, 1876; Witter, 1883; Marsh, 1887; Shimek, 1888) offer information on the presence and relative abundance of particular species, but lack quantitative data. Later stud- ies undertaken by the L .S. Bureau of Fisheries and others during the period of intense mussel har\est for the pearl button industry (Smith, 1899; Baker, 1905; Coker, 1919; Coker et ai, 1921) provided detailed information on specific taxa, but lacked quantitative data on entire mus- sel assemblages. The surve>' by Ellis in 1930-31 (Van der Schalie & Van der Schalie, 1950) provided the only quan- tified pre-lock and dam information on mussels encom- passing a large portion of the main stem L^MR. This surve\ evaluated mussel resources after several decades of unregulated harvest to suppK shell for the button industry (Baker, 1903; Coker, 1919:66-69; Knott, 1980: 11-16) and regional outbreaks of 'pearl fever' when por- tions of the UMR were depleted of mussels in search of salable pearls (Kunz, 1898:395; Baker, 1905:250-251). Moreover, the UMR of Ellis survey had undergone sig- nificant habitat changes due to construction of a h\dro- electricdamat Keokuk, Iowa (Coker, 1914), modification of channel d\namics as a result of hundreds of w ing and closing dams (Grier, 1926:92; Rasmussen, 1979:3-4), and heavy siltation (Ellis, 1936). The results of the Ellis survey reflect a stage in the degradation of the I'MR, and are not representative of naiad communities prior to EuroAmerican settlement. In 1978-80, archaeological exca\ations were conduct- ed by personnel from the University of Wisconsin-Mad- ison at a number of Woodland Tradition (A.D. 1 to .\.D. 1000) prehistoric Indian habitation sites adjacent to the l"MR in southwestern Wisconsin. Several of these sites contained food refuse deposits (middens) of freshwater mussel shells, each accurately dated by the radiocarbon method and/or through associated artifactual remains of known age. In the following report, nine prehistoric mus- sel assemblages are described. Eight of these subfossil assemblages from six sites were excavated during 1978- 80 near the city of Prairie du Chien, adjacent to present- da) Pool 10, in Crawford Count), Wisconsin, and one assemblage was excavated in 1956 b\ Da\ id A. Baerreis at a site located in the Pool 11 area of Grant County, Wisconsin (see figure 1 and table 1 ). A detailed descrip- tion of archaeological information for each site is pre- sented in Theler (1983). METHODS AND MATERIALS The mussel remains excavated during the 1978-80 field- work were bagged with their surrounding matrix and returned to the Department of Anthropolog\', University of Wisconsin-Madison. At the department's Laboratory of Archaeologv', shells were cleaned, identified, and placed into storage. The mussel assemblage collected by Baerreis in 1956 is housed at the Laboratory of Archaeology, where it was studied by the author in 1981. A series of Page 144 THE NAUTILUS, Vol. 101, No. 3 Figure 1. The location of described prehistoric shell middens in Pools 10 and 11 of the Upper Mississippi River. voucher specimens for each of the taxa in the prehistoric assemblages is on deposit at the Ohio State University, Museum of Zoology (OSUM). The ta.xonomic nomencla- ture used in this report follows that presented b\- Stans- bery (19S2j and employed by Oesch (1984). The use of certain subspecific designations for subfossil material in this report is in keeping with the catalogued voucher series at OSUM. RESULTS The nine subfossil mussel assemblages from the navi- gational Pools 10 and 11 areas of UMR have a combined total of 29,198 valves, representing 13,384 indi\iduals that could be identified as belonging to one of 28 species. The species represented, number of valves, minimum number of individuals (MNI), and the relative abun- dance (%) are presented for each assemblage in table 2. The MNI were determined by the maximum number of right or left valves of each species in each assemblage. These assemblages are combined in table 3 to facilitate comparisons with the historic surveys of Ellis (Van der Schalie & Van der Schalie, 1950). Thiel (1981) and Dun- can and Thiel (1983). The quality of shell preser\ation varies between sites and is indicated to some degree by the number of unidentifiable \alves listed for each as- semblage (table 2). These valves were specifically un- identifiable due to damage or deterioration in virtually all cases. The most abundant mussel species in the UMR subfos- sil material was the ebony shell, Fusconaia ebena (Lea, 1831) represented by 7,794 individuals comprising 58.23% of the combined assemblages. One of the most common UMR mussel species during the late 19th centur\-, F. ebena occurred on a substrate of sand and, or gravel under a moderate to strong current velocitv (Marsh, 1887: 47; Smith, 1899:290, 298; Coker, 1914:8, 1919:20, 22; Parmalee, 1967:31). The second most frequentK en- countered taxon was the monkey face mussel, Quadrula metanevra (Rafinesque, 1820) with 1,033 individuals to- taling 7.72% of the prehistoric assemblages. Q. nwta- nerva is reported to have occurred w ith the ebon\ shell in a similar habitat setting (Coker, 1919:42). Fusconaia ebena and Q. nietanevra together total 65.95%' of the UMR subfossil fauna with only eight of the remaining 26 species contributing more than 1.0% each. These eight are Amblema plicata (Say, 1817), with 920 individuals representing 6.87% of the combined as- semblages, Pleurobema sintoxia (Rafinesque, 1820) 5.91%, Quadrula pustulosa (Lea, 1831) 4.56%, Fusco- Table I. I \1R archaeological site locati' Site number Name Location Mississippi River Mile (MRM) 639.0 adjacent to abandoned side channel trace. Bullhead Slough, in the SW Vi of section 1, T7N, R7W, Crawford County, Wisconsin MRM 638.9 adjacent to abandoned side channel trace, "Mud Slough" in SW ''4 of section I. T7\, R7VV, Crawford County, Wisconsin ,\t mouth of Mill Coulee, in the NE W, NW Vt of section 6, T7N, R6W, Crawford Counts, Wisconsin MHM 6-56 9 adjacent to "Marais Lake" in the \W U, SW U of section 13, T7\, R7W, Oaw- ford County, Wisconsin: 47Crl86-l, Lower Shell Midden; 47Crl86-2, Upper Shell Midilen; 47Cr 186-3, refuse pit (Feature 26) filled with shell MRM 636.2 adjacent to "Marais Lake" in the XL '4, SE U of section 23. T7N, R7\\ . Craw- ford (bounty, Wisconsin MRM 632.3. on western shore of Schmidt Island, in the NW 'i of section 12, T6N, R7W, (Crawford County, Wisconsin MHM 608 8 in section 13, T3N, R6W. Grant C:ountv. Wisconsin 47Cr350 Bullhead Slough Shell Midden 47Cr310 Quarter Mile Shell Midden 47Crl00 Mill Coulee Shell Heap 47Crl86 Mill Cond Site 47Crl8.5 Mill liun Site 47f:r3I3 Hunter Channel Midden 47(;tl Stonefield \ih lage J, L. Theler, 19.S7 Page 145 naia flaia (Rafinesque, 1820) 4.09%, Actinonaias liga- mentina carinata (Barnes, 1823) 3.72%, Obovaria oli- varia (Rafinesque, 1820) 2.56%, Elliptio dilatata (Rafinesque, 1820) 1.54%, and Cyclonaias tuberculata (Rafinesque, 1820) with 185 indi\iduals representing 1.38% of the UMR subfossil material. The remaining 18 species each contributed less than 1% to the prehistoric UMR assemblages and include in decreasing freciuenc\ of relative abundance, Ellipsaria (= Plagiola) lincolata (Rafinesque, 1820) with 83 indi- viduals representing 0.62% of the combined subfossil ma- terial, Plcihohafiiis cypliyiis (Rafinesque, 1820), Obli- qiiaria reflexa Rafinesque, 1820, Quadrula quadrula (Rafinesque, 1820), Elliptio crassidcns crassidens (La- marck, 1819), Tritogonia verrucosa (Rafinescjue, 1820), Truncilla truncata Rafinesque, 1820, Ligumia recta (La- marck, 1819), Lampsilis higginsi (Lea, 1857), Quadrula nodulata (Rafinesque, 1820), Lampsilis ventricosa (Barnes, 1823). Lampsilis radiaia lutcola (Lamarck, 1819) (= L. r. siliquoidea (Barnes, 1823)), Potamilus alatus (Say, 1817), Lasmigona costata (Rafinesque, 1820), Las- migona complanata (Barnes, 1823), Lampsilis teres teres (Rafinesque, 1820), Strophitus undulatus undulatus (Say, 1817), and Arcidcns confragosus (Sa\, 1829) with one individual and representing 0.01% of the UMR subfossil material. DISCUSSION The value of aboriginal shell deposits as a baseline to measure change in a stream's moiluscan community since prehistoric times has been recognized by numerous re- searchers (e.g.. Morrison, 1942; Stansber\, 1965; Par- malee et al, 1980. 1982; Taylor & Spurlock. 1982; Par- malee & Bogan, 1986). The mussels recovered from the UMR aboriginal shell middens are considered to be an indicator of naiad distribution and relative abundance prior to Euro.^merican disruption of tiie main stem L'MR aquatic ecos\ stem. In the UMR subfossil assemblages, the ebon\ shell, F. ebena was the most abundant species in eight of nine discrete midden deposits and contributed nearly 60% of all individuals represented. During the late 19th century, F. ebena occurred in the main stem L'MR in dense ag- gregates or "beds' containing millions of indi\iduals (Smith, 1899:299; Coker, 1919:22). Marsh (1887:43) stat- ed that F. ebena "is the most abundant species in the [Mississippi] river, equalling in numbers all other species of Uniones combined." Coker (1919:20, 24) describes F. ebena as comprising 75 to 80%' of (commercial) species at Le Claire, Pleasant Valley, and at other points above Davenport, Iowa. In species counts made b\ Coker at commercial shell piles north of Keokuk, Iowa in 1912, he found 80% were F. ebena, 10% Q. metanevra, while seven other species (unspecified b\' Coker) accounted for the remaining 10%. It would appear that F. ebena com- prised a major c Thiel (1981) and Duncan and Thiel (1983) failed to locate an\- living indi\iduals How- ever, a small number of relict F. ebena w ere found li\ing in Pool 10 near Prairie du Chien b\ Mathiak (1979) and more recently by David Heath (personal communica- tion). Quadrula metanevra has also drastically declined relative to prehistoric numbers, with this species com- prising 0.2''t or less of the recent sur\e\s in Pool 10 (see table 2). The three ridge mussel, Amblema plicata contributes 6.87% of the combined subfossil assemblages, and ac- counted for more than 10. 0%- of an assemblage in onK- two instances (table 1). In the Ellis survey, A. plicata accounted for 7.46% of all species in the Pool 10 area region, while this taxon represented 72.1 and 52.9%, re- spectively, in systematic surve\s by Thiel (1981) and Duncan and Thiel (1983). The three ridge mussel has become the most abundant UMR mussel species. thri\ing in the often turbid, reduced \elocit\' waters of the pres- ent-da)- river. Another species showing substantial population changes in the UMR is the washboard mussel, Megalonaias ner- vosa (Rafinesque, 1820). Megalonaias nervosa was not represented in the prehistoric material from Pools 10 and 11, but has been recovered in very small numbers with prehistoric UMR assemblages near Rock Island. Illinois (Van Dyke et al., 1980). A single valve of this species was present at the Millville archaeological site (Theler, 1983) on the lower Wisconsin River 18 km above its junction with Pool 10 of the UMR. Megalonaias nervosa represented 1.33% of the Ellis sur\e\ in the Pool 10 area (Van der Schalie & Van der Schalie, 1950) and 2.8% and 6.8% of Thiel (1981) and Duncan and Thiel (1983) sur- veys, respectively, for Pool 10 (table 2). Megalonaias nervosa, like A, plicata, has shown a population increase under present-da\' habitat conditions. A number of mussel species that appear to have main- tained or slightK- increased from their prehistoric pop- ulation densities include Quadrula pustulosa, Fusconaia flava. Elliptio dilatata. and Lampsilis higginsi. Two species, Elliptio c. crassidens and Cyclonaias tubercu- lata were present in small numbers in all the prehistoric assemblages, but appear to be extirpated from the pres- ent-da\ main stem UMR, Plcihobasus cyphyus and Tri- togonia verrucosa occurred in small numbers in seven of the nine subfossil assemblages, while Pleurobema sin- toxia, Actinonaias ligamentina carinata, and Ellipsaria lineolata occur in low to moderate numbers in all pre- historic assemblages. The four latter species have been reduced to small, relict populations and P. cyphyus is extirpated in the UMR Pools 10 and 11 region. Havlik and Stansbery (1978:9) have documented ap- Page 146 THE NAUTILUS, Vol. 101, No. 3 a a a c o Q. 1. O (N c-l O O ^ rt d d d d CO O "T ^ 22 "^ o « o -c c = < c § S <"' ,- >.— ' >- a S ^ 2 « s -a O 2 S ■;; •-^0 0 c (J o — <— 'CTicO-HmcO]--< ddtod'Tdodddddd'T lOO'MCOCOdOOCOO'^GilO CDOSOJCDOOCOfMlC^OOLOt^ C^— hO> -Ht^lOCOTCOCO'— '00 CO CO -^ C^ ■^ ■^ .'_2 -*^ ^- g g . f^ ~'j2 C^ "^ --J -^ J2i 5 2 Si a 3 CO 2 t^ - —•CO _,- 00 00 ~ ^ ? '' -ii ^ a. a. ^ o = in a O o ^ 2! "^1 ST 00 00 2 ■^ ■^ 00 : 5; X ^ c c •^ en I cooot— irsTOroooocoto 00 o-HinintNO-^ooco— I 05 -~ind-^dddddd COOTt^OcOOCC— 'O "CO " — '05COi ~-< ~-i CO 05 Cl 00 -^ o 05oooor^;D;D"^ooot— oi -Tooa5i-oo— 'OcMc-)-H o dxdoiddddddd d o IM O I 8 t~ 00 -^ to O) -*h r., r^ O 2 5 li, U, U a. =1. tij kj O -t tiJ o f-c2 .2* 5 5 5 5 ^j ^ .^' ^ ^ .2-2-5 a.:=-S-S-=5S in £ 1 -o c J. L. Theler, 1987 Page 147 o U M a CO o^ -H O ^ < o o CO I 51 r^ '^' O ^ i. I 00 3 O J; _: Q E < 00 o « o I- -T- u < o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o o t^ o o o o o o o o o O O -H o O O OJ o o o o o — o o o o o o o O C' o o O O O CI o o o — o o o o O O O '-< O O O M o c-i -T — t x> 00 05 o^ CO CI -r oj ooo^oa>c>cocioi— i^o O C] CI — < -T t^ t^ ;D O ^ C^ CI OO 00 lO CI CI -^ — < Ocj — ^00;0^t--tC'Tci — . — . o coa5t^oa5 c) ic r- CI yD -r cjo CJlOOOOLOCl-^QOC^C^C] 00 -H u^ _ ^ —I lOCOCO-^oooOcOiOcOC^Oc^O^ co^Dci-H-^cjr^— ijo-^io^c-r OOciOcO-H-^lOOOlCOO cq ic lO o> cj ci o ^ t^ -r c] ;d o a> t^ CO lO O 00 t^ — ■ go CO t^ ot^cocoG^Oc^cir^cir^r^c^ CD -r — < — ■ ou:^t-o>o^r^co™oc^a;a5 Oi/^CO^^t^O^cOcOTOcO^^^H ooooodcicdcocioodoo -H in Oc0O^r^cDcD00c0Oin.-H-H in -r -H o — ' -H -T — < C5 CJ — < CO CI GO ^CDI^CICOCOOOOiOCCcoocr^ COCOO— icOOOCO'TO^COcOTCO OOCDOCOLOci-T-OOC^O^ CI c) ci co-H— ioot^ooi~-ooco ci C] « -H ^^cioooo-roocDcocor^^^ O^ lOCILOO— I 00 lO -T CO CO C4 C0t--05TOOOOOOr^ O: OlOiOcOOOOOOOC^ o — •O'T'OooooocrJai 00 O^LOOcOOOOOOO— < I -^ CI -H I- CI •roooooo -H oc 05 O lO lO CD CO 05 t^cDOcDOOOOOc^— • -^ r ^-T— 'ooooooo o o I o - - \ ^ CI CD 00 CO T t^ CO 'T t^ CO iCC0c0OCI^-"OOOOO O — 'O— loooooooo m CIiOOOcOCJO^^OOoO I 00 CI CI CO I CO Ot-050cDCOO-H ^ S 05 t— _ 00 m CI co' CD cicooor'0r^ooo50ci ci lO CI05-?"COOCOOO-^00 o o cics— ioooocrJooo i o o I o CIiOOOCIOCIOO^OO I o lO »o IC COOIOTOCOOOCIOO^ f C5 CI -^ — I mix o o T coiooo-roocioC'O o CI oqiocDocioo — ooo o CO UO — OOOcDciocOCJO I O o I o CI O^COICOCIOO-^OOO I ? 00 00 050COOO — OO O 00 CI o C -T IC cD_ in — ' — r CI 5 O c "0 ■ii CU 2 o s u. undiila confragosu a complan a costata £ E 3 verrucosa qtiadnda metancvra nodulata pustulosa plicata ebena flava V tubercula IS cyp!iyits la sintoxia crassidens latata lineolata ilivaria truncata ^ a a c^ C4. teres teres radiata lut higginsi ventricosa Oj > > C o < -^ ^ o o < ■^c^-s-s^^rs-H-S^icJ^r'-^ -J -2 = 3 ^ ^ ^ --^ ^ a iC >. - = or a >^ S = = = = =:22^-S-a.^c: . ^ ~ ^ ■57- .;:; ~^ '^ "^ "^ •^ ^ ■y^ c -J _>. F E 3 Strop! Arcick Lasmi Lasmi ^ 2 c ^ Ellipsa Obova Trumi li Lamps Lami)s Lamps Lamps •J5 ^ H =« C/5 C/l Page 148 THE NAUTILUS, Vol. 101, No. 3 Table 3. .X comparison of soint- prehistoric and modern freshwater mussel (naiad) assemblages from the uiJjjer Mississippi Ri\er. Pool 10 Data source: Numl> ler ot niaivi duals: This report; subfossil 13,.384 Ellis, 1930-31 1,126 Thiel. 1981 4,516 Duncan and Thiel, 1983 12,150 % Famil) L'nionidae Subfamily .■Vnodontinae Anodonta imhecillis Say, 1829 Anodonta xuhorbiculata Say, 1831 Anodonta grandis subspp. Strophitus undulatus iindulatiis (Say, 1817) Arcidens confragosus (Say, 1829) Simpaonaias ambigua (Say, 1825) Lasmigona complanata (Barnes, 1823) Lasmigona costata (Rafinesque, 1820) SubfamiK Ambleminae Mcgalonaias nervosa (Rafinesque, 1820) Tritogonia verrucosa (Rafinesque, 1820) Quadrula quadrula (Rafinesque, 1820) Quadrula metanevra (Rafinesque, 1820) Quadrula nodulata (Rafinesque, 1820) Quadrula pustulosa (Lea, 1831) Amblema plicata (Say, 1817) Fusconaia ehena (Lea, 1831) Fusconaia flava (Rafinesque, 1820) Cijclonaias tuberculata (Rafinesque, 1820) Plethobasus ctjptujus (Rafinesque, 1820) Pleurobema sintoxia (Rafinesque, 1820) Elliptio crassidens crassidens (Lamarck, 1819) Elliptio dilatata (Rafinesque, 1820) Subfamily Lampsilinae Ohliquaria rcflexa Rafinesque, 1820 Actinonaias ligamcntina carinata (Barnes, 1823) Ellipsaria lineolata (Rafinesque, 1820) Obovaria olivaria (Rafinesque, 1820) Truncilla truncate Rafinesque, 1820 Truncilla donaciformis (Lea, 1827) Leptodea fragilis (Rafinesque, 1820) Potamilus alatus (Say, 1817) Potamilus ohiensis (Rafinesque, 1820) Potamilus capax (Green, 1832) Toxolasma parvus (Barnes, 1823) Ligumia recta (Lamarck, 1819) Lampsiiis teres teres (Rafinesque, 1820) Lampsilis teres anodontoides (Lea, 1831) Lampsiiis radiata luteola (Lamarck, 1819) Lampsilis higginsi (Lea, 1857) Lampsiiis ventricosa (Barnes, 1823) 0.00 0.00 0 00 0,01 0,01 0 00 0.04 0.04 000 0.24 0.37 7.72 0.09 4.56 6.87 58.23 4.09 1.38 0.58 5.91 0.28 1.54 0.55 3.72 0.62 2.56 0.13 0,00 0.00 0.05 0.00 0.00 0.00 Oil 0.02 0.00 0.07 0.10 0.08 99.97 0.89 0.00 7.19 0.09 0.27 0.09 0.00 0.00 1.33 2.04 0.09 0.09 0.71 2.93 7.46 0.18 1.24 0.09 0.00 0 00 0.00 3.20 3.02 0.53 0.36 0.36 2.04 0.09 4.44 6.39 0.00 0.09 0 00 0.53 47.51 0.27 5.68 0.09 0.71 100 00 <0.1 0.0 0.3 0.3 0.2 0.0 <0.1 0.0 2.8 0.0 3.1 0.2 3.2 6.7 72.1 0.0 5.9 0.0 0.0 0.0 0.0 0.8 1.2 <0.1 0.0 1.4 1.0 0.9 <0.1 0.4 0.0 0.0 0.0 0.1 0.0 0.0 0.0 0.1 0.3 101 0 1.6 <0.1 0.8 0.4 0.3 0.0 0.1 0.0 6.8 <0.1 1.8 0.1 0.9 3.5 52.9 0.0 3.5 0.0 0.0 <0.1 0.0 2.2 2.1 <0.1 0.1 0.9 5.3 6.7 4.8 2.4 0.1 0 0 <0.1 0.6 0.0 <0.1 0.4 0.3 1.6 100 2 proximately 44 species of freshwater mussels that are known to liave occurred in the Pool 10 area of the UMR, in contrast to the 28 taxa represented in the described preliistoric assemblages. This disparity of 16 species ap- pears to be due in part to a bias by prehistoric harvestors against nnissel taxa ha\ ing a small adult shell size which were uncommon in all assemblages In the subfossil as- semblages, no individuals of Toxolasma parvus (Barnes, 1823) or Truncilla donacifornm (Lea, 1827) were re- covered, while both species are presentK widespread and locallv common in the Pool 10 area. Mussel species hav- ing a slightK larger shell size, e.g., Truncilla truncate and Ohliquaria rcflexa are rare, but persistent in the subfossil assemblages. Juveniles of any taxon were rare or absent in the assemblages. It is assumed that small shelled individuals were not harvested as a food source at the sites considered, indicating a cultural bias towards large shelled species or individuals. J. L. Theler, 1987 Page 149 Other factors possibK influencing the species com- position of tlie subfossil assemblages include water depth, w hich may have restricted prehistoric mussel harvesting to depths suitable for hand collecting. Any species that were preferentialK deep water forms, may be dispro- portionateK' rare. AdditionalK', species characteristic of a low velocit) current or backwater habitats with soft substrates (e.g., some Anodontinae) are rare or absent in the described assemblages. FinalK, it is probable that a number of species, in addition to the previousK discussed A. plicala and M. nervosa, have dramatically increased in number or ex- panded their range northward in the UMR under the influence of the large scale habitat modifications of recent decades. This appears to be the case for Aiwdonta stib- orbiculata, Sa\, 1831 (Havlik, 1981), and is perhaps true for T. parvus and T. donaciformis. Other species re- corded historically have always been rare and have a sharply circumscribed habitat preference {e.g.. Ciim- berlandia monodonta (Sa\, l>i2%) ind Simpsonaias am- bigiia (Sa%-, 1825)), or are extralimital when encountered in the main stem UMR (e.g., Alasmidonta marginata, Sa\ , 1818). These taxa are not unexpectedh' absent from the prehistoric assemblages. ACKNOWLEDGEMENTS Funding for portions of this work was pro\ided by a grant from Historic Preser\ation Grants-in-Aid, admin- istered in Wisconsin in conjunction with the National Register of Historic Places program b\ the Historic Pres- ervation Di\ ision of the State Historical Society of Wis- consin. The Laborator\ of Archaeolog\ , at the University of Wisconsin-Madison, provided space for analysis. I wish to thank Dr. James Stoltman (University of Wisconsin-Madison), principal investigator for the Drift- less Area Archaeological Project, who directed excava- tions aimed at the retrieval of molluscan data, and David Heath of La Crosse, Wisconsin, for sharing his unpub- lished data with me on Fusconaia ehena. I would like to acknowledge the valuable and insightful comments b\ two anon\ mous reviewers on an earlier version of this manuscript. FinalK', a debt of gratitude goes to m\' wife, Susann Theler, who t\ped se\eral drafts of this manu- script. LITERATURE CITED Baker, F. C. 1903. Shell collecting on the Mississippi. The Nautilus 16:102-105. Baker, F. C. 1905. The molluscan fauna of McGregor, Iowa. Transactions of the Academy of Science of St Louis 15(3); 249-258. Coker, R. E 1914. Water-power de\elopment in relation to fishes and mussels of the Mississippi. U.S. Department of the Interior, Washington, DC, Bureau of Fisheries, Doc- ument No. 805, Appendix VIII, 28 p. Coker, R. E. 1919. Fresh-water mussels and mussel industries of the United States. U.S. Department of the Interior, Washington, DC, Bureau of Fisheries Bulletin 36:13-89 Coker, R. E. 1930. Studies of common fishes of the Mississippi River at Keokuk. U.S. Department of the Interior, Wash- ington, DC, Bureau of Fisheries Bulletin 45:141-225. Coker, R. E., A. F. Shira, H. W Clark, and A D Howard. 1921. Natural history and propagation of fresh-water mussels. U.S. Department of the Interior, Washington, DC, Bureau ot Fisheries Bulletin 37:76-181. Duncan, R. E, and P. A. Thiel. 1983. A survey of the mussel densities in Pool 10 of the Upper Mississippi River. Wis- consin Department of Natural Resources, Technical Bul- letin No. 139, Madison, WI. 14 p. Ellis, M. M. 1936. Erosion silt as a factor in aquatic en\iron- ments. Ecology 17(l):29-42. Fuller, S. L. H. 1980. Historical and current distributions of fresh water mussels (Mollusca: Bivalvia: Unionidae) in the Upper Mississippi River. In. Rasmussen, J. L. (ed). Pro- ceedings of the UMRCC [L'pper Mississippi River Con- servation Committee] Symposium on Upper Mississippi Riser bivalve mollusks. Upper Mississippi River Conser- vation Committee, Rock Island, IL, p. 72-119. Grier, N. M. 1926. Report on the study and appraisal of mussel resources in selected areas of the Upper Mississippi River, 1920-25. American Midland Naturalist 10(1):89-I10. 113- 134. Havlik, M. E. 1981. The northern extension of the range of Anodonta suborbiculata Sa\- (Bi\al\ia: Unionidae), The Nautilus 95(2):89-90- Havlik, M. E. 1983. Naiad mollusk populations iBi\al\ia: Unionidae) in Pools 7 and 8 of the Mississippi River near La Crosse, Wisconsin .•\merican Malacological Bulletin 1: 51-60. Havlik, M. E. and D. H. Stansbery. 1978. The naiad mollusks of the Mississippi River in the vicinity of Prairie du Chien, Wisconsin. Bulletin of the American Malacological Union 1977:9-12. Knott, M. J. 1980. The pearl button industr\ and its impacts on Mississippi River mussel fauna. In: Rasmussen, J. L. (ed). Proceedings of the UMRCC [Upper Mississippi River Conservation Committee] Symposium on Upper Mississip- pi River bivalve mollusks. L'pper Mississippi Riser Con- servation Committee. Rock Island, IL, p. 11-16, Kunz, G. F. 1898. The fresh-water pearl and pearl fisheries of the United States. Bulletin of the United State Fisheries Commission 17:375-426. Marsh, W. A. 1887. Brief notes on the land and fresh-water shells of Mercer Co., III. The Conchologist Exchange 1 (No. 9 and 10). Mathiak, H. .\. 1979. A river sur\e) of the unionid mussels of Wisconsin 1973-1977. Sand Shell Press, Horicon. WI. 75 p. Morrison, J. P. E. 1942. Preliminar\ report on mollusks found in the shell mounds of the Pickwick Landing Basin in the Tennessee River Valley. In: Webb, W S. and D. L. Dejarnette. .^n archeological survey of Pickwick Basin in the adjacent portions of the states of Alabama, Mississippi and Tennessee Bureau of American Ethnolog\ Bulletin 129, Washington, DC, p. 337-392. Oesch, R. D. 1984. Missouri naiades: a guide to the mussels of Missouri Missouri Department of Conservation, Jeffer- son City, MO, 270 p. Parmalee, P. W. 1967. The fresh-water mussels of Illinois. Popular Science Series, Vol. \'1II, Illinois State Museum, 108 p. Parmalee, P. W and A. E. Bogan. 1986. Molluscan remains from aboriginal middens at the Clinch Ri\er breeder re- Page 150 THE NAUTILUS, Vol. 101, No. 3 actor plant .site, Roane County, Tennessee. .American Ma- lacoiogiral Huiietin 4(l):25-37. Pannalee, V. W., W . E. Klippel, and .A, E, Began. 1980 Notes on the prehistoric and present status of the naiad fauna of the Middle CXmiberland Ri\er. Smith Count) , Tennessee. The Nautilus 94(31:93-10.5. Parmalee, P. \V., \V. E. Klippel, and A. E. Bogan. 1982. Ab- original and modern freshwater mussel assemblages (Pel- ecypoda: Unionidae) from the Chickamauga Reservoir, Tennessee. Brimleyana 8:75-90. Perry, E. VV. 1979. A survey of L'pper Mississippi River mus- sels. In: Rasmussen, J. L. (ed.). A compendium of fishery information on the Upper Mississippi River, second edi- tion. I pper Mississippi River Conservation Commission, Rock Island, IL, p 118-139. Pratt, \V. H. 1876. List of land and fresh water shells found at Davenport, Iowa. Proceedings of the Davenport .Acad- emy of Natural Science 1:165-168. Rasmussen, J. L, 1979, Description of the Upper Mississippi River, In: Rasmussen, J. L. (ed.). A compendium of fishery information on the L'pper Mississippi River, 2nd ed. Upper Mississippi River Conservation Commission, Rock Island. IL, p. 3-20. Shimek, B. 1888. The moUusca of eastern Iowa. Iowa Uni- versity Natural History Bulletin 1:56-81. Smith, H. M. 1899. The mussel fishery and pearl-button in- dustry of the Mississippi River. U.S. Fisheries Commission Bulletin 1898, 18: 289-314. Stansbery, D. H. 1965. The molluscan fauna. In: Prufer, O, H. (ed.). The McGraw Site: a study in Hopewellian dy- namics. Cleveland Museum of Natural History, Scientific Publications, No, 4, p. 119-124, Stansbery, D. H. 1982. .\ list of the unionid mollusks of the Ohio River system. The Ohio State University Museum of Zoology Reports for 1982, No. 4. Stevenson, K. P. 1985. Oneota subsistence-related behavior in the driftless area: a study of the Valle\ X'iew site near La Crosse, Wisconsin. Doctoral dissertation. Department of .Anthropology, University of Wisconsin-.Madison, 601 p. Surber, T. 1913. Notes on the natural hosts of fresh-water mussels. U.S. Bureau of Fisheries Bulletin 32:101-116. Taylor, R. W. and B. D. Spurlock. 1982. The changing Ohio River naiad fauna: a comparison of early Indian middens with today. The Nautilus 96(2):49-5I. Theler, J. L. 1983. Woodland tradition economic strategies: animal resource utilization in southwestern Wisconsin and northeastern Iowa. Doctoral dissertation. Department of .Anthropology, University of Wisconsin-Madison, 433 p. Thiel, P. A. 1981. .A survey of unionid mussels in the Upper Mississippi River (Pools 3-11). Wisconsin Department of Natural Resources, Technical Bulletin No, 124, Madison, WI, 25 p. Van der Schalie, H. and ,A. Van der Schalie. 1950. The mussels of the Mississippi River. .American Midland Naturalist 44(2): 448-466. Van Dyke, A., D. F, Overstreet, and J. L. Theler. 1980. Ar- chaeological recovery at ll-RI-337, an early Middle Woodland shell midden in East Moline, Illinois. The Wis- consin Archeologist 61(2):125-256. Witter, F. M. 1883. The mollusca of Muscatine County and vicinity. The Muscatine Conchological Club, Muscatine, Iowa, S. W. Cassino and Company, Boston, 24 p. THE NAUTILUS 101(3):151-153, 1987 Page 151 Henry Drummond Russell (1908-87) with a Bibliography of His Malacological Publications and a List of New Taxa Introduced by Him Kenneth J. Boss Museum nf Coniparati\e Zoology Harvard Universitv Cambridge, MA 0213S, USA The Mollusk Department of the Museum of Comparative Zoolog\- at Harvard Universit\ regretfullx' announces that our colleague, Dr. Henry Driunniond Russell, died on Januar\ 24, 19(S7 at the age of 78 after a long illness; tragically, his wife, Elizabeth Meade Russell, subsecjuent- ly died on February 24, 1987. His immediate family, including his three daughters, Louise Russell, Barbara R. Williams, anil Ca tithia R. Howe, and all their friends and colleagues grieve these losses. Henry was born in Boston on September 5, 1908, the son of Charles Theodore Russell and Louise Rust. After his preparatory education at Miss Woodwards School in Boston, the Longwood Da\ School in Brookline, and the Middlese.x School in Concord, Massachusetts, he enrolled at Harvard College in 1928, graduated in 1932 with an A.B. degree, and took his Master's and Doctoral degrees at Boston Universit> in 1933 and 1940. After graduation from Harvard in the midst of the Depression Henry did volunteer work in the Mollusk Department which, of course, brought him into close association with Dr. William J. Clench, the then curator; this experience also facilitated his study of the proso- branch gastropod family Xeritidae in the western At- lantic, a topic w hich constituted his doctoral dissertation. Several field trips occupied Henry's energies during the summer months in the thirties when he accompanied Dr. Clench and others to the West Indies: in 1934 to northern Cuba; in 1935 and 1936 to Cat Island and Long Island in the Bahamas; and in 1937 to Puerto Rico as well as to the northern portion of Santo Domingo, par- ticularly the Bahia de Samana, Puerto Plata, and Monte Cristi on the island of Hispaniola. One recalls the gusto with which Henry and Bill would relate various anec- dotes of these adventurous expeditions. Once, in Oriente, in the dining room of a small pension in which a dog snoozed in the corner, Henry, who was the acknowleged official translator since he knew several words of Spanish, was instructed by Bill to ask the waiter what was to be the dessert that evening. Henry did so and to their sur- prise, the waiter turned on his heel, marched across the room and kicked the dog out. What actually Henry had said in Spanish was never discovered. These field trips resulted in the collection of natural historv- specimens for the museum, particularly a large series of terrestrial, treshwater, and marine mollusks. During the summer of 1938, Henry worked with the Department of Fish and Game of New Hampshire, mak- ing a survey of the Merrimack River watershed and its central lakes and streams to determine the feasibilitv for stocking them with fish; these field collections and studies resulted in the publication, with W. J. Clench, of papers on the freshwater mollusks of the Merrimack and Con- necticut River watersheds (see Bibliography ). Granted the title of Honorary .Assistant Curator of Mollusks in the MCZ in 1940, Henry subsequently joined the Division of Marine Fishes in the Department of Con- servation of Massachusetts as Assistant Biologist where he was involved in a state aid project tor the restocking and cultivating of the clam flats of coastal Massachusetts; he resigned this position in March, 1942. Page 152 THE NAUTILUS, Vol. 101, No. 3 From June, 1942 to Marcli, 1943, he wa.s A.s.sistaiit to Dr. Thonia.s Barl)ovir, the Pre.sident of tlie New England Museum of Natural Histor\ , no\\ the Museum of Science. For two months in the spring of 1943, as a participant in the war effort, Henr\ collaborated with Dr. Charles H. Blake at the Massachusetts Institute of Technology in an Army study of insect pests in supplies. Then from September, 1943 to October, 1944 he was involved with a study, supported by the United States Navy, of sub- marine illumination with Dr. George L. Clarke at the Woods Hole Oceanographic Institution. Then Henr\- began work at the Fatigue Laboratory at Harvard where studies were conducted on various as- pects of human physiology under the stress of thermal extremes, especialK on conditions affecting men \\ orking in \er\' cold climates. From 1947 to 1948, he pursued studies on boring and fouling organisms at the William F. Clapp Laboratories in Duxbury, Massachusetts. in 1948, Henry commenced a long association with Boston L niversitv' when he was appointed as Instructor in General Biologv . An effective and enthusiastic teacher, he assumed charge of the General Biological Laboratories which introduced Freshmen to the subject; he lectured on evolution, genetics, and several other subjects. During the summer of 1952, he conducted a survey of Spy Pond in Arlington under the auspices of the Massachusetts Department of Public Health. From the fall of 1952 until 1961 he was Assistant Professor of Biology when he once again returned to research as an Associate of the newly established Systematics and Ecology Program at the Ma- rine Biological Laboratories at Woods Hole. Here he published his useful handbook on laboratory techniques for narcotizing and preserving animals for future study. He was president of the Boston Malacological Club 1936-38, 1940-42, and 1957-59 and for many years served as its Conchological Recorder, a role in which he excelled and one in which he both educated and enter- tained his audience with his superb sense of humor; he became Councillor-at-Large tor the American Malaco- logical Union in 1971, and was active in the American Association for the .\d\aiicement of Science as well as being a member of the corporation of the Bermuda Bi- ological Station and the secretary of the Cape Cod Shell- fish Corporation. Relatively late in his career, Henry culminated his work on the group ol animals he enjo\ed most with his book Index Siidibninchia, which was published in 1971 by the Delaware Museum of Natural History. This in- dispensable contribution consists ol a delineation of all the scientific papers published on this unique group of basicalK shell-less snails from the time of Belon and Rondelet in the middle of the sixteenth centur\ to 1965. It also comprises a catalogue of all taxonomic names applied to these animals, including especialK their ge- neric and specific epithets alphabeticalK arranged; spe- cial indices are provitled t(j assist a researcher in studying the geographic ranges and natural history oi these ani- mals. A special supplement, covering the literature on nudibranchs between 1966 and 1975 was published in the summer of 1986 by the Department of Mollusks in the M(;Z, of which he had been an Associate since 1972. Henry was alwa\s active!) supportive of civic affairs in his home town of Dover, Massachusetts, He was a member of the Town Warrant Committee in 1941, the Dover Conservation Commission, and chairman of the Public School Association in 1946; additionally, he sup- ported enthusiastically other conservation oriented or- ganizations, including the Hale Reservation of Westwood and the Neponset Conservation Association, of w hich he served as director in 1975. bibliography of the malacological public:ations of h. d. russell' 1935a. Some nudibranchs of Bermuda, w ith a descrip- tion of a new species. The Nautilus 49(2):59- 61, pi, 4 (October). 1935b, Corijphella pcUucida .Alder & Hancock. The Nautilus 49(2):65-66 (October), 1937a. Li\ ing rainbows of the sea. Bulletin of the New- England Museum of Natural History No. 82;3- 5, text fig, (January). 1937b. Cratena veronica N'errill. The Nautilus 50(4): 142 (April). 1938. Freshwater shells of New Hampshire. In: Bio- logical survey of the Merrimack Watershed. New Hampshire Fish and Game Department, Con- cord, NH, Surve> Report No. 3:201-206, pis. A and B, text fig. 1 (with William J. Clench as senior author) (December). 1940a. Freshwater shells of New Hampshire. In: Bio- logical survey of the Connecticut Watershed, New Hampshire Fish and Game Department, Concord, NH, Survey Report No, 4:222-227, pis. III-IV, text figs,' 83-84 (with William J, Clench as senior author) (March). 1940b. The Recent mollusks of the family Neritidae of the West Indian Region. .Abstract of a disser- tation, Boston University Graduate School. Bos- ton, MA, 3 p. (May). 1940c. Mr. B. wants better fishing. New England Nat- urali.st No. 7:19-23 (June), 1940d. Freshw ater shells of New Hampshire. The Nau- tilus 54(2);52-53 (with William J. Clench as se- nior author) (October). 1940e, Some new Neritidae from the \\ est Intlies, Me- morias de la Sociedad Cubana de Historia Na- tural "Felipe Poe\ '" 14(4):257-262. pi. 46 (De- cember). 1941 The Recent mollusks of the famiK Neritidae of the VWstern Atlantic. Bulletin oi the Museiun of Comparative Zoology, Harvard (-ollege 88(4): 347-404, pis. 1-7, text figs. 1-4 (August), ' Excluded are tlie numerous literature reviews, entitled the 'Article ol the niontli, which appeared in the New York Shell ('iuij News from Scplcmher 1972 until 1979, K. J. Boss, 1987 Page 153 1942a. 1942b. 1944. 1946. 1951. 1952. 1955. 1960. 1963. 1964. 1966. 1967. 1968a. 1968b. 1969. 1971a. Obser\aliuns on tlif leeding of Aculidia pap- illosa L., v\ith notes on the hatching of veHgers oi Cutliona atnocna A. & H. The Nautikis55{3): 80-82 (January). A new species of Onchidiupsis from Baffin Land. National Research Council of Canada, Cana- dian Journal of Research 20:50-55, te.vt figs. 1- 9, 1 table (Februar> ). A stitch in time. Tlie Nautilus 58(l):32-33 (July). Ecologic notes concerning Elysia chlorotica. Gould and Stiligcr fuscafa, Gould. The Nau- tilus 59(3):95-97 (January). Seasonal distribution of Najadicola ingens (K.) (Acarina) in a New Hampshire pond. Ps\che 5S(3):111-119, graphs 1-6, table 1 (with Arthur G. Humes as senior author) (September). The Du.xbury Bay 1950 set of Mya arenaria L. The Nautilus 66(1):7-10, text fig. 1 (July), A new clam industry in New Englantl, The Nau- tilus 69(2):53-56 (October). Heteropods and pteropods as food of the fish genera, Thiinniis and Alcpisauriis. The Nau- tilus 74(2):46-56, map, lists 1-3. tables 1-3 (Oc- tober). Notes on methods for the narcotization, killing, fixation, and preservation of marine organisms. S\stematics-Ecology Program. Marine Biologi- cal Laborator\ , Woods Hole, MA, 70 p. (April). New England nudibranch notes. The Nautilus 78(2):37-42, table 1 (October). Kelaart's Cevlon opisthobranch species. The Nautilus 79(4):120-122 (April). Some nudibranch names. Tliirt\-second Annual Meeting, The American Malacological Union, Inc., Annual Reports for 1966, Bulletin 33.38- 39 (abstract) (probably Januar\). [Although at the end of the Table of Contents a date of De- cember 1, 1966 is given, normally these were not mailed or distributed until early the follow- ing \ ear; beginning w ith Bulletin 34 tiie mailing date is given.] Chromodoris califonuensis and C calcnsis (Notes and News). The Nautilus 81(4):140-141 (April). A bibliography of nudibranchiate interstitial fauna. Psammonalia (Newsletter of the Asso- ciation of Meiobenthologists), No. 6:11-13 (No- vember). [Psammonalia states on its cover: This document is not part of the scientific literature and is not to be cited, abstracted or reprinted as a published document.] Interstitial opisthobranchs from North America. American Zoologist. Vol. 9(4):615 (with Donald J. Zinn as senior author) (November). A t\pe oi Nudibranchia bibliography. Thirty- sixth Annual Meeting, The .\merican Malaco- logical Union, Inc., Annual Reports for 1970, Bulletin 37:56-57 (abstract) (Februarv). 1971b. index Nutlifiraiicliia. A catalog of the literature 1554-1965. The Delaware Museum of Natural History, iv -I- 141 p. (July). 1971c. E\olution of a nudibranch bil)li()graphy. The Echo No. 4. Abstracts and Proceedings of the Fourth Annual Meeting of The Western Society of Malacologists, Pacific Grove, CA, June 16- 19. 1971, p. 28 (December). 1971d, A list of the nudibranchs of India and adjacent seas. Symposium on Indian Ocean and Adjacent Seas, Cochin, India, Januar> 12-18, 1971. Ma- rine Biological Association of India, Abstract No. 149, Section XV, p. 91 [title only] (no month). 1977. A glimpse of Bermuda nudibranchs. Newsletter Bermuda Biological Station for Research 6(2):2 (October). 1978. Leopold and Rudolph Blaschkas nudibranch glass models. The Nautilus 92(4):167-172, fig. 1 (with Catharine G. Kessler as senior author) (October). 1979. Some shell-less New England marine snails. Aquasphere. Journal of the New England Aquarium 13(3):28-31, 6 text figs. (December). 1980. In\ertebrates in glass. Aquasphere. Journal of the New England Aquarium 14(2):30-33, 4 text figs, (with Catherine [sic] G. Kessler as senior author) (September). 1986. Index Nudibranchia, Supplement I, 1966-1975. Special Occasional Publications No. 7, Depart- ment of Mollusks, Museum of Comparative Zo- ology, Harvard L'niversity, 100 p. (July). NEW MALACOLOGICAL TAXA INTRODUCED BY H D. RUSSELL clcnchi Russell 1935a. Glossodoria. The Nautilus 49(2): 59, pi. 4, figs. .A-E (holotype. Museum of Comparative Zoology No. 109,085; t\'pe-locality. Ferry Reach [St. George], Bermuda). clenchi Russell 194Se. Ncritina. Memoriasde la Sociedad Cubana de Historia Natural "Felipe Poe\ " 14(4):261, pi. 46, figs. 1-2 (holot\pe, Museum ol Comparative Zoology No. 115,701; type-locality, Rio Manjon, 7 km SE of Puerto Plata, Santo Domingo). kingmanicnsis Russell 1942b. Onchidiopsis. Canadian Journal of Research 20:50, figs. 1-9 (holotype, Ro\al Ontario Museum, Toronto, No. 17,260; type-localit\, Lake Harbour Fiord, Baffin Land). piratica Russell 1940e. Scritina. Memorias de la Socie- dad Cubana de Historia Natural "Felipe Poe\ 14(4): 259, pi. 46, figs, 3-4 (holot\pe. Museum of Compar- ative Zoology No. 115,702; type-locality, Wounta La- goon, Nicaragua). weyssei Russell 1940e. Smaragdia viridis. Memorias de la Sociedad Cubana de Historia Natural "Felipe Poey " 14(4):257, pi. 46. figs. 5-6 (holotx pe. Museum of Com- parative Zoology No. 88,815; type-locality, Miami, Florida). THE NAUTILUS 101(3):154, 1987 Page 154 New Names for Two Species of Cancellaria (Mollusca: Gastropoda) Richard E. Petit 806 St. Charles Road Nortli Nhrtlf Reacli, SC 29582. USA The purpose of this short note is to propose replacement names for two species of Cancellaria: C. quasilla nomen novum for C. cretacea E. A. Smith, 1899 non Nyst, 1881 and C. laddi nomen novum for C. petHi Ladd, 1982 non Olsson, 1967 Cancellaria quasilla Petit nomen novum Cancellaria cretacea E. A. Smith, 1899:245. Not Cancellaria cretacea \\st. 1881:8. Cancellaria cretacea E. A. Smith; McVrdle, 1901: pi, 11, Bgs. 5, 5a. Discussion: This species is known from the hoiotype ifigure 1), which is in the collection of the Zoological Survey of India, from 360 fathoms off the Travancore coast of south India, and from a badl> broken specimen in the collection of the Academy of Natural Sciences of Philadelphia (ANSP 291936, Andaman Sea. south Bur- ma). Cancellaria quasilla resembles species of Merica in o\erall form, and the columellar structure is similar to that of C. rosewateri Petit, 1983 from the Gulf of Mexico. It differs from species of Merica in that it lacks a well- defined anterior canal. A determination of subgeneric placement must await additional study on the entire family. Etymology: From the Latin quasillum (dimin. of qua- lum, a wicker basket) for the woven aspect caused by the strong cords and ribs. Comments: The hoiotype is refigured here. Apprecia- tion is expressed to Dr. N. \'. Subba Rao, Superintending Zoologist, Zoological Survey of India, C^alcutta, for con- firming the presence of the hoiotype in the Survey col- lection, and for furnishing photographs of the hoiotype. Cancellaria {Merica) laddi Petit nomen novum Cancellaria {Merica) petili Ladd, 1982:57, pi. 14, figs. 16-18. Not Cancellaria (Cancellaria ) petili Olsson, 1967:44. Discussion: This species is from Vanua Levu, Fiji (Plio- cene; unnamed formation). As Ladd stated, it is closely related to the Recent Indo-Pacitic Cancellaria (Merica) oblonga Sowerln, 1825, from which it differs in being more slender and much more strongly sculptured. - y» .-^^ Figure 1. Hoiotype of Cancellaria quasilla Petit nomen no- iinn (= C. cretacea Smith non Nyst). Dorsal and ventral views. Height 25 mm; width 19 mm. Etymology: This replacement name honors the late Dr. Harry S. Ladd, with whom I enjo\ed man\ interesting and educational conversations on the Tertiar\ faunas of the Indo-Pacific. LITERATURE CITED Ladd, H S. 1982 Cenozoic fossil mollusks from Western Pacific Islands; gastropods (Eulimidae and Volutidae through Terebridae). U.S. Geological Survey Professional Paper 1171:1-100, pis. 1-41. Mc.'^rdle, .A. F. 1901. Illustrations of the the zoology of the Ro\al Indian Marine Surve\- Ship h^vestigator Mol- lusca: Pt, III, pis. 9-13 Calcutta. Nyst, P. H. 1881. Conch\ liologie des Terrains Tertiaires de la Belgique, Pt. 1. Annales du Musee Ro>al d'Histoire Naturelle de Belgique 3:1-263 Olsson, A. A. 1967. Some Tertiar\ mollusks from South Flor- ida and the Caribbean. Paleontological Research Institu- tion, Ithaca, New York, 61 p., 9 pis. Petit, R. E. 1983. A new species of Cancellaria (Mollusca: Cancellariidae) from the northern Gulf of Mexico. Pro- ceedings of the Biological Societv of Washington 96(2): 250-252. Smith, E. A. 1899. Natural histor\ notes froiii H M Indian Marine Survey Steamer 'Investigator . , . On Mollusca from the Bay of Bengal and the Arabian Sea. Annals and Mag- azine of Natural Historv, Ser. 7, 4:237-251 INSTRUCTIONS TO AUTHORS THE NAUTILUS publishes papers on all aspects of the biology and systematics of moUusks. Manuscripts de- scribing original, unpublished research as well as review articles will be considered. Brief articles, not exceeding 1000 words, will be published as notes and do not re- quire an abstract. 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Tucker Abbott American Malacologists, Inc. P.O. Box 2255 Melbourne, FL 32902 CONSULTING EDITORS Dr. William K. Emerson Department of Living Invertebrates The American Museum of Natural History New York, NY 10024 Mr. Samuel L. H. Fuller 1053 Mapleton .Avenue Suffield. CT 06078 Dr. Robert Hershler Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC 20560 Dr. Richard S. Houbrick Division of Mollusks National Museum of Natural History Smithsonian Institution Washington, DC 20560 Mr Richard I. Johnson Department of Mollusks Mu.scum of Comparative Zoology Harvard Universit) Cambridge, MA 02138 Dr. Aurele La Rocque Department of Geology The Ohio State University Columbus, OH 43210 Dr. James H. McLean Department of Malacology Los .\ngeles County Museum of Natural History 900 Exposition Boulevard Los Angeles, CA 90007 Dr. Arthur S. Merrill % Department of Mollusks Museum of Comparative Zoology Harvard University Cambridge, MA 02138 Dr. Donald R. 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Postage outside the United States is an additional US $2.00 for surface and US $10.00 for air mail. All orders should be accompanied by payment and sent to: THE NAUTILUS. P.O. Box 3430, Silver Spring, MD 20901. Change of address: Please inform the publisher of your new address at least 6 weeks in advance. All communications should include both old and new addresses (with zip codes) and state the effective date. THE NAUTILUS (ISSN 0028- 1344) is published quarterly by Trophon Corporation, 363 Crescendo Way, Silver Spring, MD 20901. Second Class postage paid at Silver Spring, MD and additional maihng offices. POSTMASTER: Send address changes to: THE NAUTILUS P.O. Box 3430 Silver Spring, MD 20901 TH E^NAUTI LUS CONTENTS Volume 101, Number 4 November 6, 1987 ISSN 0028-1344 Richard S. Houbrick Description of a new, giant Ataxocerithiiim species from Australia with remarks on the systematic placement of the genus (Prosobranchia: Cerithiopsidae) 155 A new species of Phyllonotus (Muricidae: Muricinae) from Isla del Coco, Costa Rica 162 A revision of the genus Benthovoliita with notes on the evolution of the subfamiK Ptychatractinae (Prosobranchia: Turbinellidae) 166 The freshwater mussels (Unionidae) of the upper Ohio River, Greenup and Belleville Pools, West Virginia 182 Anthony D'Altilio Barbara W. Myers Donald R. Shasky M. G. Harasewych Michael A. Zeto William A. Tolin John E. Schmidt Robert E. Balie New distributional records for Polygyriscus virginianus (Burch, 1947) (Pulmonata: Helicodiscidae) 186 W. B. Saunders P. D. Ward Sympatric occurrence of living Nautilus (N. pompilius and N. stenomphalus) on the Great Barrier Reef, Australia 188 William K. Emt Walter E. Sage, Tson III On the availability of names proposed in Pacific Shell News, Tokvo, 1970-72 194 Edward J. Petuc h A new Ecphora fauna from Southern Florida 200 Marine Biological Laboratory LIBRARY NOV 1 6 1987 Woods Hole, Mass. THE NAUTILUS 101{4): 155-161, 1987 Page 155 Description of a New, Giant Ataxocerithium Species from Australia with Remarks on the Systematic Placement of the Genus (Prosobranchia: Cerithiopsidae) Richard S. Houbrick Dei)artnu-iit (it Iinertebrate Zoology National Museum of Natural History Smithsonian Institution Wasiiington, DC 20560, L^SA ABSTRACT A new, large Ataxocerithium species is described and gi\en the name eximiiim. This new species differs considerabl> in shell characters from an\ other known Ataxocerithium species. Shell characters, the radula, and anatomical characters, such as an acrembolic proboscis, suggest Ataxocerithium be assigned to the Orithiopsidae. Comparison of the new species with other taxa is made and a brief discussion of the genus is presented. INTRODUCTION The genus Ataxocerithium Tate, 1894 is not well known. The limits and systematic position of the genus are poorl\' understood, and the anatomy is undescribed. The genus usually has been allocated to the Cerithiidae Ferussac (Cossmann, 1906:92; Thiele, 1929:212; Wenz, 1940:759; Powell, 1951:111; Cotton, 1959:361; Iredale & Mc- Michael, 1962:44), and recently to the Cerithiellidae Go- likov and Starobogatov {Marshall, 1978:60). A cursory examination of the man\- species attributed to this taxon suggests that Ataxocerithium, seiisu lato, probably com- prises several genera. The alpha taxonomy of this group has not been accomplished; consequently, the full extent of this radiation is not known nor is the geographic dis- tribution of the group and its component species under- stood. While studying Pacific and Indian Ocean Ataxoceri- thium species, specimens of a large, distinctive, unde- scribed species, dredged in deep water off S\ dne\ , New- South Wales, Australia were examined in the Australian Museum, Sydney. Much of the material was preserved in alcohol and, although the body whorls were poorly preserved, was suitable for dissection and study of the radula, operculum, and gross anatomy. L nfortunateK the state of the pallial gonoducts was not able to be determined. The gross anatomy of another species. A. scriipulosum Iredale, 1936, was also examined and com- pared with the new species, and a tentative diagnosis of Ataxocerithium was formulated. Most Ataxocerithium species ha\e relativeK small shells, not exceeding 20 mm in length. The disco\er\ of this large, distinguished species enriches our concept of this group and thus merits a full description. MATERIALS AND METHODS Material examined: A total of 21 specimens were ex- amined (AMS = .Australian Museum, Sydney): R.V. TANGAROA. Sta. U220, 32°59'S, 152°33.5'E, 381-444 m, off Newcastle, NSW (AMS cl42398, cl42391); R.V. TANGAROA, Sta. U208, 34°13.8-15.8'S, 15r26.6'- 29.1'E, 381-395 m, S of Sydney, NSW (AMS cl42391); FRV KAPALA. 39°45'S, I5r49-50'E, 439 m, off Sydney, NSW (AMS CI42392); FRV KAPALA, Sta. K75-12-06, 34°16-21'S, 15r24-28'E, SE of Botany Bay, NSW (AMS C142394, t\pe-lot); FR\' KAPALA, Sta. K75-05-07, 412 m, 34°2S-34'S, 151°17-19'E, E of Ft. Kembla, NSW (AMS C142396); FRV KAPALA. Sta. K75-12-07, 421 m, 33°43- 48'S, 151°48-51'E, E of Svdnev, NSW (AMS cl42395); FRV KAPALA. Sta. K75-12-05, 34°32-39'S, 151°15-19'E, 412 m, E of Kiama, NSW (AMS cl42393) (all Australia). Methods: Three specimens were extracted from their shells, dissected, and examined under a Wild Vl-8 dis- secting microscope. Only the head-foot and lower mantle cavity were well preserved. Radulae, protoconchs, and opercula were studied with electron microscopy using a Zeiss Novascan-30 instrument. The shells of all 21 spec- imens were studied, but as many of these were damaged or immature, only seven adult, complete shells, with fully developed apertures, were measured to establish the range of variation (Table 1). SYSTEMATIC RESULTS SuperfamiK Cerithiopsacea H. and A. Adams, 1853 Family Cerithiopsidae H. and .\. .Adams, 1853 Genus Ataxocerithium Tate, 1894 Diagnosis: Shell turreted, whorls inflated, sculptured with axial ribs and spiral cords. Body whorl wide with Page 156 THE NAUTILUS, Vol. 101, No. 4 R. S. Houbrick, 1987 Page 157 Table 1. R ange of measurements in se\en aili lilt > ^lells . of Ataxoccri th^ iuni cxiniuun new species. Aperture Aperture No axial No. spiral Stiilistic Length WHlth lengtli width nils cords No. whorls X 43.2 9.5 6.8 5.9 22.7 4.7 20.7 SD 2,67 0 51 0 37 0,59 25 1.3 0.49 Range 40.1-4' four tiny denticles. Lateral tooth (figures 14, 15) large, robust, roughly rectangular shaped, w ith thick central shaft and supporting longitudinal ridge. Tip or main cusp of lateral tooth large, pointed, flanked by strong inner buttress-like cusp and with 2-3 tiny, sharp, outer denticles. Basal plate of lateral tooth broad with pointed, outer, posterior corner and longitudinal basal butress ending in slight bulge. Outer front edge of lateral tooth with medial-basal flange. Marginal teeth (figure 16) long, rod-shaped, with broad bases, brush- like apices, and long, sharp tips. Inner marginal tooth Figures 1-12. Ataxocerithium eximium new species. 1-3. Holotype, .\\\S C142394 (45.7 mm length), showing apertural, right lateral, and dorsal views. 4. Shell base of holot\pe. showing close apposition of columellar lip and outer lip base (figure length 10.5 mm). 5-7. Parat\pe (USNM 862328, 41 mm length), showing apertural. left lateral, and dorsal views 8. Shell base of paratype. 9. Free side of operculum (4.3 mm length). 10. Detail of aperture and body whorl, showing large columellar lip, long anterior siphon and cancellate whorl sculpture (figure length, 15 mm), 1 1. Left lateral detail of body whorl showing extended columellar lip and cancellate whorl sculpture (figure length, 15 mm). 12. SEM of papillate, smooth protoconch and early sculpture of first teleoconch whorls (bar = 200 tim). Page 158 THE NAUTILUS, Vol. 101, No. 4 Figures 13-16. Radula of Ataxocerithiurn cximium new species 13. Radular ribbon with marginal teetli folded back to show rachidian and lateral teeth (bar = 20 uni). 14. Radular ribbon tilted to expose undersurfaces of rachidian and lateral teeth (bar = 20 nm). 15. Details of rachidian and lateral teeth (bar = 10 m'")- it>- Details of marginal teeth showing brush-like tips (bar = 10 Mm). ape.x with 5 inner flanking, needle-shaped denticles and 2-3 sharp, outer flanking denticles. Outer marginal tooth same, but with only 1 outer flanking denticle. Animal (figure 17): Preserved animal pink. Foot long, separated from sole by wide, deep furrow around its entire edge (figure 17, fs). Propodium broad, crescent shaped anteriorly, and with dorsal surface pigmented dark brown. Deep propodial mucus gland at leading edge of sole (figure 17, pmg). Sole of foot light pink and w ith many transverse wrinkles; divided longitudinally by deep cleft (figure 17, cs) that begins just behind propodial mucus gland. Head has f)road, short, muscular snout (figure 17, sn) with bilobed tip and mouth (figure 17, m) leading to large introvert. Pair of long cephalic tentacles (figure 17, t) each with large eye (figure 17, e) at outer peduncular base. Eyes black with red center. Mantle edge (figure 17, me) smooth. Very long, strap-like col- umellar muscle extends posteriorly for 5.5 w horls. Mantle cavity large, spacious. Osphradium a long, high, narrow, w hite ridge, slightly swollen at its base and thinly tapered at its dorsal edge. Ctenidium large, adjacent to osphra- dium and comprised of long, finger shaped, triangular filaments. Hypobranchial gland moderately de\eloped. Rectum wide. Pallial gonoduct thick and glandular. .Acrembolic proboscis present: Introxert short, somew hat cuticular interiorly ; separated from opening of mouth by circular band of muscles. Pair of large (1 mm long), oval-rectangular jaws with scaly surface in oral cavity. Buccal mass elongate and w ith long, taenioglossate rad- ular ribbon, which emerges distally from beneath right side of buccal mass, crosses over it and lies on left side of esophagus. Anterior esophagus appears to be cuticu- larized. Pair of large, orange, ascinous sali\ar\ glands present; lett glanti larger and extends partially through nerve ring; right gland smaller, and lies anterior to nerve R. S. Houbrick, 1987 Page 159 ring. Large mid-esophageal gland w itli inner epitlielium thrown into many thin transverse filaments that appear to extend the entire esophageal circumference. Nervous system epiathroid. Thin, short, but distinctive connec- tives between cerebral and pleural ganglia. Right pleural ganglion about one-half the size of right cerebral gan- glion and with long supraesophageal connective. Left pleural ganglion with short connective to subesophageal ganglion. Long connectives join pleural ganglia to an- teriorK located pedal ganglia. Holotype: .\MS C142394, length 45.7 mm, width 10.1 mm; 5 paratypes, AMS C153005; 2 paratypes, USNM 862328. Type locality: Dredged 421 m, 34°21-16'S, 151=24- 2.S'E, SE of Botany Bay, NSW, Australia. Etymology: From the Latin adjective, exiiuiu.s, a, um, distinguished, extraordinar\. DISCUSSION This large, many-whorled, unusualK sculptured species is the largest known Ataxocerithium species, and not easiK confused with any other congener. Four other nominate s\ mpatric species of Ataxocerilhium occur off New South' Wales (Iredale & McMichael, 1962:44), and these are all appreciably smaller. The high spired shell and silky-cream ground with its thin, golden-tan, spiral lines, and the fine, prickly, cancellate sculpture (figures 10-12) readily distinguish A. cximiiim. The liighK tur- reted cerithiid species, Cerithium matukense Watson, 1886, looks very much like A. eximium, but differs in having weaker collabral axial riblets, straight sided whorls, and lacks the protruding columellar lip joining the lower outer lip, and the smooth papillate protoconch of the latter taxon, Ataxocerithium eximium does not appear to vary much in sculpture (see table 1), but the onl\ known specimens are all from a narrow locale. Ataxocerithium eximium. to date, has been dredged on soft bottoms in depths of about 380-450 m, from a narrow geographic range off the coast of Sydney, New South Wales. It probably occurs in similar habitats and depths along the southeastern Australian coast. Some shells are covered by a thin growth of sponge. The rectum was filled with gray sediment and detritus comprising ar- thropod appendages, bryozoan pieces, foraminiferans, sand grains and sponge spicules. This species probably lives and feeds on sponges, as does Ataxocerithium scru- pulosum Iredale, 1936, which has been collected on sponges by SCUBA divers (Ian Loch, personal commu- nication). Most cerithiopsids appear to be sponge feeders. No drilled shells have been seen. Shells frequently have broken apertures suggesting predation b\ crabs or fish. Ataxocerithium eximium differs so much from any other congener that it might be considered representative of a new genus. While there appear to be major differ- ences in shell and radular morphology among various Ataxocerithium species (personal observation), the group has never undergone revision nor has the internal anat- me pmg Figure 17. Head-foot of Ataxocerithium eximium. Abbrevi- ations: cs = longitudinal cleft in sole of foot; e = eye; fs = furrow separating foot from sole; m = mouth; me = mantle edge; op = operculum; pmg = propodial mucus gland; sn = snout; t = cephalic tentacle. omy been seriously studied. Although I have examined the anatom> of two species, all species are best referred to Ataxocerithium, sensu lata, until the group is more comprehensi\eK known. Powell's (1951:191, fig. 1 (34)) figure of the radula of Ataxocerithium pullum (Philippi, 1845), the only other published figure of the radula of an Ataxocerithium species known to me, resembles the general morphology of the rachidian and lateral teeth of A. exirrnum shown herein, although the marginal teeth of A. pullum look quite different. I have studied the radula of another Ataxocerithium species from Natal, South Africa, in which the radular teeth differ in shape and cusp number from those of A. eximium. in e\er\ aspect. Thus, there is probabK a wide range of variation in radular mor- phologies in this group. Although most authors have placed Ataxocerithium in the Cerithiidae, the radula of A. eximium is more indicative of those of cerithiopsids (superfamiK' Ceri- thiopsacea). However, as mentioned above, Ataxoceri- thium radular morphology is variable. Marshall (1978: 60) stated that his preliminar\- studies of Australasian species of Ataxocerithium suggest that the genus should be referred to the Cerithiellidae Golikov and Starobo- Page 160 THE NAUTILUS, Vol. 101, No. 4 gato\ , 1975, but presented no supporting data. The Ceri- tliiellidae is a poorl\ defined group: to mv knowledge, no author has listed tlie apomorphic characters defining this group or has established its familial status with any supporting data. The radula of Cerithiella nietula Loven, as depicted by Sars( 1878: table 7, fig. 4), differs markedly from that of A. exiiniiiiu in lacking the pair of basal denticles and in hav ing fewer cusps on the cutting edge of the rachidian tooth. In A. eximium, the base of the lateral tooth is much longer and has a basal ridge; more- over, the marginal teeth are long and with brush-like tips, while the> are simple, short hooks in Cerithiella metula. Marshall (in litt.) has suggested that the two large cusps on the lateral tooth of Ataxocerithium and Cerithiella are homologous and that the Cerithiella rad- ula originated b\ reduction from an Ataxoccrithium- like plan, but available data on both taxa are too few to allow anything other than speculation about radular evo- lution, at this point. Marshall (1980:85) subsequently re- garded the Cerithiellidae as a subfamily of the Triforidae Jousseaume (Cerithiopsidae). The Triforidae, largely based on shell characters, is another poorly defined, higher category ta.xon, which lacks the salient autapomorphies necessary for familial status. While agreeing with Mar- shall's proposed scheme of relationships, I disagree with the ranking. As so little is known about the ta.xa Ceri- thiella and Triforts Deshayes, other than conchology, it seems premature and non-parsimonious to accord them familial or even subfamilial status. They are best re- garded as higher category taxa of uncertain status within the Cerithiopsidae. The protoconch (figure 12) of Ataxocerithium exi- mium is quite different from the protoconch of the Ataxocerithium species depicted by Marshall (1980:86, fig. 1, F), which closely resembles that of a Triforis species depicted in the same figure. It seems that there is wide variation in Ataxocerithium protoconch mor- phology. Marshall (1978:54) has pointed out the extreme diversity of cerithiopsid radulae. The longitudinal cleft in the sole of the foot of A. eximium is exactlv like that of Cerithiopsis poivelli Mar- shall, 1978 [Marshall (1978:53, fig. 2)] (Cerithiopsidae), and very much like that depicted by Marshall (1977: 113, fig. 1, A) for Mciaxia exaltata (Powell, 1930) (Tri- phoridae), and Sella adamsii (Lea, 1845) (Triphoridae), which I have dissected. The anatomy of the anterior alimentar\ canal of A. eximium (cuticularized anterior esophagus) and A. scrupulosum differs from that of other described cerithiopsids by the presence of a short, but well-developed snout. Otherwise, it is similar in layout to the alimentary canal of Cerithiopsis species (Ceri- thiopsidae), as described by P>etter (1951:567-576), and not unlike that of Mastonia species (Triphoridae), de- scribed by Kosuge (1966:303-305). The layout of the nervous system of A. eximium is also similar to that described for Mastonia (Kosuge, 1966:305). Thus, Ataxo- cerithium species appear to share characters found in cerithiopsids and triphorids, but have more in common with cerithiopsids. Anatomical ditierences described in the literature between cerithiopsids and triphorids do not justif\' their separation into two separate superfamilies. In conclusion, study of the anatomy and radula of Ataxocerithium eximium and A. scrupulosum definitely excludes them from the Cerithiidae and supports their allocation to the Cerithiopsidae, superfamiK Cerithiop- sacea, near Cerithiella and Triforis. If it is shown that Ataxocerithium is a sister group to the latter two taxa, they may all comprise a separate clade w ithin (subfamily Cerithiellinae) or separate from (Cerithiellidae) the Ceri- thiopsidae. The genus Ataxcjccrithium needs much attention: cur- rent know ledge indicates that this genus is probably more complex than previously thought, and its exact compo- sition and systematic position w ill remain uncertain until the entire complex is reviewed. ACKNOWLEDGEMENTS I thank Dr. Winston F. Ponder of the .'Australian Museum, Sydney for pointing out this species to me. I also thank Mr. Ian Loch, collection manager of the same institution, for the loan of the specimens. Mr. Bruce Marshall of the National Museum of New Zealand, Wellington, critically reviewed the manuscript and contributed valuable ad- vice. Photography was done by Mr. Victor Krantz, Smith- sonian Photographic Services. Ms Susanne Braden, Smithsonian Scanning Electron Microscope Laboratory, assisted with the SEM. LITERATURE CITED Adams, H. and A. Adams. 1853. The genera of Recent Mol- lusca; arranged according to their organization, van Voorst, London, l(l-8):256 p. Cossmann, M. 1906. Essais de paleoconchologie comparee. F. R. de Rudeval, Paris, 7:261, 14 pis Cotton, B. C. 1959. South .•\ustralian Mollusca .\rchaeogas- tropoda. W. L. Hawes, Adelaide, 449 p., 215 figs, Fretter, V. 1951. Observations on the life histories and func- tional morphology of Cerithiopsis tubercularis (Montagu) and Triphora perversa (L). Journal of the Marine Biolog- ical Association of Great Britain 29:567-586. C;olikov, A. N, and Y. I. Starobogatov. 1975. Systematics of prosobranch gastropods, Malacologia 15(l):185-227. Iredale, T. 19.36. Australian niolluscan notes. No. 2. Records of the Australian Museum, Svdne\ 19:267-340, pis. 20- 24. Iredale, T. and D. F. McMichael. 1962. A reference list of the marine mollusca of New South Wales. The .\ustralian Museum, Sydney, Memoir 11:109 p. Kosuge, S. 1966. The famiK' Triphoridae and its systematic position, Malacologia 4(2):297-324. Lea, H. C. 1845. Description of some new fossil shells, from the Tertiary of Petersburg, \a. Transactions of the .Amer- ican Philosophical Societ\, 2nd series 9:229-274 (1-48), pis. 34-37. Marshall, B. A. 1977. The de.xtral triforid genus Mctaxia I Mollusca: Gastropoda) in the south-west Pacific. New Zea- land journal of Zoology 4:111-117. Marshall, B, A. 1978. Cerithiopsidae (Mollusca: Gastropoda) R. S. Houbrick, 19S7 Page 161 of New Zealand, and a provisional classiiication of the family. New Zealand Journal of Zoology 5:47-120. Marshall, B. A. 1980. The systematic position of Triforis Deshayes (Mollusca: Gastropoda). New Zealand Journal of Zoology 7:85-88. Philippi, R. A. 1845. Diagnosen einiger neuen Conch\lien Archiv fuer Naturgeschichte 11:50-71, Powell, A, W, B, 1930. New species of New Zealand Mollusca from shallow -water dredgings. Transactions of the New- Zealand Institute 60:532-543. Powell, A. W. B. 1951. Antarctic and Subantarctic Mollusca: Pelecypoda and Gastropoda. Discovery Reports 26:47-196, pis. 5-10. Sars, G. O. 1878. Bidrag til Kundskaben om Norges Artiske Fauna. 1. Mollusca Regionis Arcticae Norvegiae. Brogger, Christiana, 466 p., 18 pis. Tate, R. 1894. L'nrecorded genera of the older Tertiar\ fauna of Australia, including diagnoses of some new genera and species. Journal of the Royal Society of New South Wales 27:167-198, pis. 10-13. Thiele, J. 1929. Handbuch der systematischen Weichtier- kunde. Jena, 1(1 ):v + 376 p. W atson, R. B. 1886. Report on the Scaphopoda and Gaster- opoda collected b\ H.M.S. Challenger during the sears 1873-76. /;!; Report on the scientihc results of the voyage of H.M.S. Challenger during the years 1873-76 15(42): 756 p., 53 pis. Wenz, W. 1940, Gastropoda, 1: ,'\llgemeiner Teil and Pro- sobranchia. In: Schindewolf, O. H. (ed). Handliuch der Palaozoologie. Borntraeger, Berlin, 4:721-960. THE NAUTILUS 101(4):162-165. 1987 Page 162 A New Species of PhyUonotiis (Muricidae: Muricinae) from Isla del Coco, Costa Rica Anthony D'Allilio Barbara W. Myers Department of Marine hnertebrates San Diego \atnral Histor\ Museum P.O. Box 1390 San Diego, CA 92112, USA Uunald R. Shasky Field Associate San Diego Natural History Museum 834 W. Highland Ave. Badlands, CA 92373, USA ABSTRACT Phyllonotus eversoni, a new species from Isla del Coco, Costa Rica, is described and compared to P. regius (Swainson, 1821) and P crythrastomus (Swainson. 1831). INTRODUCTION Isla del Coco (also known as Cocos Island), Costa Rica, is a small uninhabited island situated appro.ximately 600 km SSW of Puntarenas, Costa Rica, at 5°33' latitude and 87°03' longitude. Cocos Island and the numerous islets which surround it are situated on the Cocos Ridge, which lies about 1,800 m (1,000 fm) below sea level (Hertlein, 1963:221-223). The marine molluscan fauna at Cocos Island has pre- dominantly Eastern Pacific affinities and probably was transported to the island from the mainland by west- wardly directed ocean currents (Hertlein, 1963:226-227). However, he listed five species with Indo-Pacific origin. Emerson and Old (1964:90-91) and Shasky (1983:144, 1986:3-5) have noted several more species with Indo- Pacific affinities collected at Cocos Island. Emerson (1967: 89) discusses this transport of Indo-Pacific mollusks across 3,000 miles of open sea and ofters as explanation that dispersal may occur by means of the eastward flowing North Ecjuatorial countercurrent duritig the free swim- ming veligcr stage. Moiitoya ( 1983:35, 39-40) listed four species of marine mollusks found only at C-ocos Island. Stingley (1984:28) described Oliva foxi with the only known locality listed as Ok'os Island. For a complete bibliography of O)cos Island molluscan faunal studies, see Montoya ( 1983:325-353, 1984:33-44). A complete list of the marine mollusks found at Cocos Island is in preparation (M. Montoya and D. R. Shasky). Family Muricidae Rafinesque Subfamily Muricinae Rafinesque Genus Phyllonotus Swainson, 1833 Type species: Miirex margaritensis (Abbott, 1958), new name for Murcx impcrialis Swainson, 1831 (not M. im- pcrialis Fischer de W aldheim, 1807) b\ subsequent des- ignation. Phyllonotus eversoni new species (figures 1, 2) Description: Shell broadly fusiform, pear-shaped; pro- toconch of undetermined number of w horls; eight post- nuclear, convex w horls; spire motlerateK high; body w horl broadly ovate; suture deeply impressed within a channel; aperture ovate; anal sulcus forming a deep trough be- tween body and apertural varix; inner lip closely adher- ent above, forming a moderateK raised inductura below, seven small nodes on anterior portion of columella; outer lip strongly crenulate and erect; weakly perceptible spi- ral cords on body, ending in broad open spines at ap- erture; aperture Urate within; siphonal canal broad, mod- eratelv long, distal portion narrow and recurxed; left margin of canal simple, right side of canal follows in- dentations and grooves; siphonal fascicle with two well- preserved distal portions of previous canals; pseudoum- bilicus present at jimcture of canal, siphonal fasciole and inductura; three spinose varices on body whorl, penul- timate whorl and antepenultimate whorl; first four post- nuclear whorls with strong axial ribs and little indication of varices; fifth, sixth, and seventh postnuclear whorls with gradualK diminishing axial ribs but with a series of nodes present at intersection of axial and spiral sculp- ture; varices erect, with broad open spines in two axial parallel rows on leading side; eight primary spines on Figures 1, 2. Phyllonotus eversoni new species. 1. Holotype, USNM 859932, .southwest side of Isla Maiiuelita, tangle net in 66 ni 143 mm long. 2. Paratype 1, USNM 859933, Chatham Bay, Cocos Island, tangle net in 66 m, 189 mm long. A. D'Attilio et al.. 1987 Page 163 Page 164 THE NAUTILUS, Vol. 101, No. 4 l)(nh wlidii Hiul fi\e on canal; buttresses e.xtremely fine, thin walled, crossing the .sutural channel and abutting the w liorl above; five diftuse weak spiral cords on bocK' whorl, four somewhat stronger cords on canal, entire dorsum rippled and crossed b\ microscopic spiral threads. Color: Pale pink to deeper fleslu pink between varices, fading on canal; two to three weak brown bands on shoulder; leading sides of nodes on bocK w horl are brown; two brown spots on dorsal and \ entral sides of the varices, one at shoulder and one at lower half of body whorl; some brown color on spines of canal; parietal callus lus- trous brown above inductura, extending into anal sinus; a diagonal band of brown from previous parietal area preserved on last two whorls; columella deep pink. Type locality: In 66 m, southwest side of Isla Manuelita, in tangle net. March 20, 1984. Holotype: USNM 859932 (figure 1) 143 mm long x 77 mm wide. Type material: Paratype I: USNM 859933 (figure 2) 189 mm long x 104 mm wide. April 25, 1986. 66 m, Chatham Bay, Cocos Island, in tangle net. Paratype 2; SDNHM 91514 138 mm long x 81 mm wide. March 20, 1984. Roca Sucia in 27 m. Paratype 3: 170 mm long x 92 mm w ide. March 20, 1984. East side of Isla Manuelita in 18 m. Collection of Gene Everson. Paratype 4: 128 mm long x 61 mm wide. April 26, 1987. 90 m Chatham Bay, Cocos Island, Collection of D. R. Shasky. Paratype 5: 130 mm long x 67 mm wide. April 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of D. R. Shasky. Paratype 6: 151 mm long x 80 mm wide. April 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of D. R. Shask\ . Paratvpe 7; 166 mm long x 84 mm wide. .April 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of D. R. Shasky. Paratype 8: 103 mm long x 55 mm wide. April 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of Douglas \on Kriegelstein. Parat>pe 9: 140 mm long x 7,5 mm wide. April 26, 1987, 90 m Chatham Bay, Cocos Island. Collection of Douglas von Kriegel- stein. Paratype 10: 144 mm long x 74 mm wide. April 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of Douglas von Kriegelstein. Paratvpe 11: 160 mm long X 85 mm wide, .\pril 26, 1987. 90 m Chatham Bay, Cocos Island. Partial specimen. Collection of Douglas von Kriegelstein. Paratype 12: 168 mm long x 82 mm wide. April 26, 1987. 90 m Chatham Ba\-, Cocos Island. Collection of Douglas von Kriegelstein. Paratv pe 13: 134 mm long x 66 mm wide, .\pril 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of Kirstie Kaiser, Paratype 14: 174 mm long x 87 mm wide. .April 26, 1987, 90 m Chatham Bay, Cocos Island, Collection ot Kirstie Kaiser, Paratype 15: 137 mm long x 69 mm wide. April 26, 1987. 90 m Chatham Bay, Cocos Island. Collection of Michel Montoya. Paratype 16: 151 mm long x 75 mm wide, .'\pril 26, 1987, 90 m (Ihatham Ba\\ Cocos Island, Collection of Michel Montoya, Paratype 1, the largest specimen collected, is iulK mature with a completely developed outer lip This spec- imen has a long canal (80 mm compared to 44 mm on the holot\ pe). There are 11 to 12 spiral cords on the body w horl which become evanescent in the intervarical areas, except on the canal. The outer lip on this large paratype is strongly reflexed, the crenulations terminating at right angle to the aperture; the anterior two-thirds portion has 24 short, strong, close-set lirae or denticles on the inner edge of the outer lip. The nodes on the columella num- bering 10 in this specimen become stronger and elongate. The color of this specimen beneath a white opaque layer of soft calcium (intritacalx) is pale pink where the shell has been abraded. The parietal callus is a lustrous brown, the columella and inner side of aperture are pale pink. The number of cords on the body whorl of this new species varies, as do the number of nodes on the colu- mella, the length of the canal, and the number of spines on the varices. The reflected outer lip and the denticles on the inner lip vary with growth and maturits . Oper- culum is typically muricoid, unguiculate, and thickened marginallv with a depressed central area on its inner surface, nucleus basal. Etymology: We are pleased to name this species for Gene Everson who collected and donated the holotspe and who has been generous in the past in contributing specimens for scientific study. DISCUSSION This new species is most closely related to Phyllonotus regius (Swainson, 1821) and P. enjthrostomus from which it differs in the following characters: P. regius has six to se\en varices, P. cnjthwslomits has four to fi\e \arices, while the new species has only three varices. The broad sutural channel found on the new species is lacking on both P. regius and P. enjthrostonius. D'Attilio (1984) has shown that occasional specimens of P. enjthrostomus can have the same parietal and inductural coloring as P. regius and the new species. Vokes (1984) figured this new species as Chicoreus (Phyllonotus) new species. ACKNOWLEDGEMENTS We thank Fernando Cortes, Chief of Scientific Investi- gations of the Costa Rican National Park Service, for permission to studv the molluscan fauna of Cocos Island. The crew of the motor schooner "Nictoria af Karlstad" has alwa>s provided untiring assistance to aid this study and we owe them a debt of gratitude. In his fieldwork Dr. Shasky has been especialK helped b\ Mr. Gene Ev- erson, Ms. Kirstie Kaiser, Dr. Michel Montoya, and Mr. Douglas von Kriegelstein. We are most grateful to Mr. Gene Everson for donation of the holotype to the Na- tional Mu.seum of Natural History, Smithsonian Insti- tution. We extend our appreciation to Mr, David K. Mulliner for the photography used in this paper. Partic- ular thanks to Dr. William K. Emerson for his critical re\ie\\ of the manuscript and for obtaining se\eral ref- A. D'Attilio ct at.. 19S7 Page 165 erences for us. Mrs. Theo Fusby ver\ kindly typed the manuscript. LITERATURE CITED Abbott. R, T 1958. The marine inoliusks of Grand Cayman Island. B \\ I, .Academ) Natural Sciences, Philadelphia. Monograph 11, L38 p., 5 pis. D Attiho, A. 1984, An unusual color form of Phyllonolus erythrostomtis (Swainson, 18'31). The Festi\us 16(l);6-7, 4 figs. Emerson, W. K. 1967. Indo-Pacific fauna! elements in the Tropical Eastern Pacific, with special reference to the mol- lusks. Venus 25(3-4):8.5-9.3, 1 text hg. Emerson, W. K. and W. E. Old, Jr. 1964. Additional records from Cocos Island. The Nautilus 77(3):90-93. Hertlein, L. G. 1963. Contribution to the biogeograph) of Cocos Island, including a bibliography. Proceedings Cal- ifornia .Academy Sciences 4th Series 32{8);219-289, 4 figs. Montova, M. 1983. Los Moluscos Marinos de la Isla del Coco, Costa Rica. I. Lista .\notada de especies. Brenesia 21:32.5- 353. Montoya, M. 1984. Marine mollusks of Cocos Island, Costa Rica. I. Bibliographic compilation of species. Western So- ciet> of Malacolog) Annual Report (1983) 16:33-44. Rafinesque, C. S. 1815. Analyse de la nature ou tableau du univers et des corps organises. Barravecchia, Palermo, p. 136-149 Shasky, D. R. 1983. New records of Indo-Pacific Mollusca from Cocos Island, Costa Rica. The Nautilus 97(4)144- 145. Shaskv, D. R 1986 L'pdate on mollusks with Indo-Pacific faunal affinities in the tropical eastern Pacific IV. The Festivus 18(l):3-5, 8 figs. Stingley, D. V. 1984. A new Oliva from eastern Pacific (Gas- teropoda [sic]: Olividae). La Conchiglia 16(178-179);28. Swainson, W. 1821. Exotic conchology, 1st ed., pt. 2, 7th pi. London, 39 p., 48 pis. (2nd ed., 1841, edited by Sylvanus Hanley, p. 5-6, pi. 15.) Swainson, W. 1831. The zoological illustrations, Ser. 2, Vol. 3, p. 73, pi. 2. London. (Referenced in Sherborn as (2)11(16), 1831, pi, 73.) Swainson, W. 1833. The zoological illustrations, Ser. 2, Vol. 3, p. 67, pi. 1 (not pi. 67, Vol. 2). (Referenced in both Naeve and Sherborn as 18.33, Zoo. lllus. (2)3(22): pi. 100, Moll.) Vokes, E. H. 1984. Comparison of the Muricidae of the east- ern Pacific and western .Atlantic with cognate species. Shells and Sea Life 16(11):210-215, 10 text figs., 2 pis. THE NAUTILUS 101(4):166-181, 1987 Page 166 A Revision of the Genus Benthovohita with Notes on the Evolution of the Subfamilv Ptvchatractinae (Prosobranchia: Turbinelhdae) M. G. Harasewych Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA ABSTRACT The genus Benthovohita Kuroda and Habe, 1950 is revised and restricted to four Recent species: B. hilgendorfi (von Martens, 1897); B. gracilior Rehder, 1967; B. krigei Kilburn, 1971; and B. claydoni new species, Phenetic anaK ses using morphometric data indicate that the three eastern Indian-western Pacific species are more closeK related to each other than any is to the single species from the western Indian Ocean. Further phenetic anal- yses suggest that Benthovoluta is most closely related to the genus Surctilina from off New Zealand and the eastern Pacific, that both are more remotel\ related to the small-shelled genera Cyomesus. Metzgeria, and Ptychatractiis. all restricted to the Northern Hemisphere, and that the genera Ceratoxancus and Latiromitra are most distanth related, and ma\ not belong to the family Turbinellidae. Dissections of Benthovohita claydoni revealed that the mantle cavity and alimentary and male re- productive systems resemble those of the subfamily Turbinel- linae, while the female reproductive system more closely re- sembled those of Vasinae and Colunibariinae. A short, stout proboscis, as well as the presence of an amphipod carapace and lack of polychaete setae in the posterior alimentary canal, sug- gest a diet and mode of feeding that differ from those of other Turbinellidae. These dissections represent the first anatomical data for any species attributed to the subfamily Ptychatrac- tinae. Cladistic analyses of anatomical characters reveal that the Ptychatractinae are most closely related to the Turbinel- linae, and that the Vasinae are most distantly related to the other members of the familv Turbinellidae. INTRODUCTION The genus Benthovoluta comprises a small, poorK know ii group of fusiform turhiiiellid gastropods that inhabit tiie batliyai zone along the margins of tiit- Indian and Pacific oceans. Records are few, and the taxonomic position of the genus, as well as the often ephemeral inclusion of species within it, have been based on shell and occasion- ally on radular characters. Reports of fossil representa- tives are rare, tentative, and limited to Late Tertiary (Miocene or Pliocene) deep water deposits along the northwestern Pacific (Yokovama, 1920; Taki & Ovama, 1954; MacNeil, 1960). Kuroda and Habe (1950) erected the genus Bentho- vohita \\ ithin the family N'olutidae, and designated Phe- iiacoptygma'^ kiiensis Kuroda, 1931, a Recent species originalK proposed with some doubt as a turrid. as t\pe. These authors also included the Pliocene "Mitra" plici- fera Yokovama, 1920 (non Mitra plicifera S. \'. Wood, 1848) in Benthovoluta. but placed both these ta.\a in the synonymy of Voluta hilgendorfi von Martens, 1897 in the same publication. On the basis of a figure of the radula of B. hilgendorfi, published without comment by Habe (1952), Kuroda (1965) transferred this genus to the family Turbinellidae and suggested affinities with the genera Metzgeria Norman, 1879 and Ceratoxancus Ku- roda, 1952. Rehder (1967) noted similarities between the shell and radular morphologies of Benthovoluta and those of Surculina Dall, 1908, Ptychatractus Stimpson, 1865, and, more remotely, the fusiform species of Turbinella Lamarck, 1799. In the same paper, Rehder s\iion\TOized Phenacoptygma Dall, 1918 under Surculina. Cernohorsky (1973) used Stimpson's (1865) family group name Ptychatractidae, previously placed in the synony my of Turbinellidae b\ most authors, as a subfam- ily within Turbinellidae to include the five genera men- tioned above. Quinn (1981) proposed the genus Cyome- ■sus for a number of small-shelled species that had been relerred to Benthovoluta b\ Cernohorsky (1973), and suggested that the L'pper Cretaceous genera Mesorhytis Meek, 1876, Paleofusimitra Sohl, 1963, and Mitrodomus Sohl, 1963 as w ell as the Eocene genus Fu.simitra Conrad, 1855 might also belong to the suljfamiK Pt\ chatractinae. Based on shell morphology, Bouchet and W'aren (1985) referred the monotypic, eastern Atlantic, bathyabyssal genus Latiromitra Locard, 1897 to the famiK Turbi- nellidae, and considered Cyomesus a synonym Deep-water traw ling oH northwestern Australia by the Australian Conunonw ealtii Scientific and Industrial Or- ganization (CSIRO) as well as by commercial fishermen M. G. Harasewych, 1987 Page 167 has \ielded a number of specinieiis, including several with preserved soft parts, of a new species of Bentho- voliita that is described herein. This description includes the first account of the anatomy of an\ species attriljuted to the subfamiK Ptvchatractinae. The known species of Benthovoluta are reviewed and the plnlogenetic affin- ities of this genus, and by inference the subfamiK, are discussed. MATERIALS AND METHODS Specimens for anatomical studies were cracked in a vice, the loose shell fragments removed, and soft parts placed in 20% hydrochloric acid (HCl), to dissolve the remaining shell. Soft parts were rinsed in distilled water and re- turned to 70% ethanol for dissection. Sections for analysis of shell ultrastructure were cut using a diamond saw. Some sections were broken to ex- pose fracture surfaces, others polished and etched for a few seconds w ith 1% HCl. Radulae for SEM examination were critical point dried. In order to determine gut con- tents, the posterior esophagus, stomach, intestine, and rectum of three specimens of Benthovoluta claydoni were excised, transferred to a microscope slide, teased apart, and examined. Several drops of bleach (S*"!^ sodium hy- pochlorite, NaOCl) were then added to dissolve organic matter. After 20 minutes, the sample was diluted with distilled water, filtered through a 0.45 yum membrane filter, rinsed, dried, and examined under SEM. Scanning electron micrographs were taken using a Hitachi S-.570 SEM. The specimens of Benthovoluta listed in the material examined sections, as well as the published figure of the holot\pe of B. krigci (Kilburn, 1971: fig. 3a) were scored for the 12 characters listed in table 1. AnaKses of rela- tionships between species of Benthovoluta were confined to shell characters, as anatomical data were available for only one species, and published line drawings of the radulae of two other species lacked sufficient detail to ascertain differentiating characteristics. The mean values of the characters comprised the data matrix for phenetic analyses. To investigate the relationships between the Recent genera attributed to Ptvchatractinae, specimens or figures of their type species (listed in table 2) were chosen to serve as exemplars, and scored for the char- acters listed in table 3. These values formed the data matrix used in a second series of phenetic analyses. Fi- nally, the phylogenetic relationships between the four subfamilies of Turbinellidae were investigated using the taxa listed in table 4 as exemplars of their subfamilies, and scoring them for anatomical characters listed in table 5. Characters were polarized based on Ponders (1973) analysis of the evolution of organ s\ stems in Neogastrop- oda. Morphometric shell characters [tables 1, 2 (characters 1-9)] \\ ere determined using CONCH version 1.0 (Chap- man et ai, 1987). For phenetic analyses, the data were standardized (mean = 0, standard de\iation = 1), a Eu- cHdian distance matrix calculated, and phenograms based Table 1. Slit'il characters used in plieiietic analyses of rela- tionships between the species of Benthovoluta. Characters 1 through 8 describe the geometrv ot the generalized shell form (Harasewych. 1982). 1) Shape of the generating curve of the bod\ cavit\ (Sbcl 2) Shape of the generating cur\e of the siphonal canal (Ssc) 3) Relative siphonal length (Rsl) 4) Siphonal angle (beta) 5) .Angle of generating curve (theta) 6) Rate of whorl expansion (W) 7) Position of generating curve relative to axis (D) 8) Rate of whorl translation (T) 9) Aperture -I- siphonal canal length/shell length (\ + SCL/ SL) 10) Color pattern (C:P): solid (0), banded (1) 11) Suture (Sut): adpressed (0), abutting (1) 12) Surface sculpture on bod\ whorl (Sculp): incised spiral furrows (0). spiral cords (I), cancellate (2) on I PGM.A and single linkage (nearest neighbor) clus- tering algorithms produced using SYSTAT version 3.4 (Wilkinson, 1986). Cladistic analvses were run using PAUP version 2.4 (Swofford, 1985). Repositories of examined specimens are indicated b\' the following abbreviations: DMNH Delaware Museum of Natural History USNM National Museum of Natural History, Smithsonian Institution SAM South .African Museum WAM Western Australian Museum SYSTEMATICS Family Turbinellidae Swainson, 1S40 This famiK is best known for its large, tropical, heavy- shelled, shallow-water species that comprise the low di- versit\ subfamilies Turbinellinae and V'asinae. The bathxal subfamilies C^olumbariinae and Ptvchatractinae are far more diverse and widely distributed, ranging from equatorial to polar latitudes. Species belonging to the latter tw o subfamilies tend to be significant!} smaller and thinner-shelled. Characteristic features of the family include fusiform to biconical shells consisting of two or three layers of crossed-lamellar aragonite, bulbous pro- toconchs, open, axialK -oriented siphonal canals, and col- umellae that usually have two to four spiral folds. Oper- cula are elongate and terminally nucleate. Animals generally have a long narrow proboscis, a small radular ribbon with tricuspid rachidian and mono- or bicuspid lateral teeth, an open or partialis fused sperm groove, and lack accessor}- salivars glands. Diets consist mostK or exclusivelv of polychaetes (Hornell, 1914; Moses, 1923; Harasewych,' 1983, 1986) sipunculids (Ta>lor et al., 1980), and "worms' (Bandel, 1984). SubfamiK Ptychalractinae Stimpson, 1865 As taxa have been assigned to this, the most poorK know n subfamiK in Turbinellidae, exclusiveK on the basis of Page 168 THE NAUTILUS, Vol. 101, No. 4 Table 2. Recent genera attributed to the subfamiK Ptycha- tractinae and their t> pe species. Specimens or figures that pro- vided characters for phenetic analyses are listed Benthoioluta Kuroda and Habe, 1950 Benlhovoluta higendorfi (von Martens, 1897). USNM 824942, off Choshi, Japan (figure 1, herein; radula Rehder, 1967: fig. Ill Ceratoxancus Kuroda, 1952 Ccraloxancus teremachii Kuroda, 1952, off Tosa, Japan (Shi- kama 196.3: pi. 76, fig. 4; radula unknown) Cyomesus Quinn, 19S1 Cyomesus meehianus (Dall, 1889), lectotype, USNM 86970, BL.\KE station 100, off Moro Light, Cuba 7.32 m (Quinn, 1981: fig. 1; radula Bayer, 1971: fig, .55D) Latiromiira Locard, 1897 Latiromitra cryptodon (P. Fischer, 1882), MNHN, off Mo- rocco. 1900 m (Bouchet & Waren, 1985: fig. 676; radula unknown) Metzgeria Norman. 1879 Metzgeria albm (Jeffre>s. 1873). INGOLF station 32. Davis Strait, western Greenland (Bouchet & Waren, 1985: fig. 677; radula fig. 393) Ptychatractus Stimpson, 1865 Ptychalractus ligatiis (Mighels and Adams, 1842), USNM 414668. off Eastport, Maine, in 18 m (unpublished pho- tograph of shell; radula figure 19. herein) Surculina Dall. 1908 Surculina blanda (Dall. 1980). holotvpe, USNM 123119, off Cocos Island. Gulf of Panama in 1951 m (Rehder. 1967: fig. 7; radula fig. 10). Table 3. Shell and radular characters used in phenetic analyses of relationships between Recent genera attributed to the subfamiK Ptychatractinae. Characters 1 through 8 describe the geometrs of the generalized shell form ( Harasew \ch. 1982). 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) 11) 13) Shape of the generating curve of the body cavity (Sbc) Shape of the generating curve of the siphonal canal (Ssc) Relative siphonal length (Rsll Siphonal angle (beta) Angle of generating curve (theta) Rate of whorl expansion (W) Position of generating curve relative to axis (D) Rate of whorl translation (T) Aperture -1- siphonal canal length/shell length {.\ + SCL/ SL) Protoconch (Prot): multispiral (0); paucispiral (1) Lateral radular teeth (Lat): single cusp emanating from outer edge of basal plate (0); base of single cusp spanning all or most of the basal plate (1) Rachidian teeth with cusps spanning (Rachl): > 0.5 basal plate (0); < 0,5 basal plate (1) Rachidian teeth with basal plate (Rach2): broad, curved (0); narrow, recurved (1) based, trowel-like lateral teeth. The remaining species are referred to the genus Cyomesus Quinn. 1981. which rBay be readily distinguished from Benthovoluta on the basis of its much smaller shell, with shorter siphonal canal and proportionalK higher spire, and a radular ribbon in which the rachidian teeth are stouter, with larger, broad- er cusps, and lateral teeth that are narrow, long, and scythe-shaped. shell and radular morpholog\'. assumptions of monophy- K for this group are. at best, tentative. Shells are fusiform, high-spired, and small (rarely exceeding 100 mm), with elongate, narrow apertures and zero to four, strong to weak columellar teeth. Radulae have tricuspid rachidian and monocuspid lateral teeth. Most members of this subfamily inhabit the bathyal zone, with some species occurring at depths in excess of 2,000 m. A number of the boreal species, including the type species of the type genus of the subfamily, have been taken in less than 20 m. (ienus Benthovoluta Kuroda and Habe, 1950 Benlhovoluta Kuroda and Habe, 1950:37. Type species b\' orig- inal designation Phenacoptygma? kiiensis Kuroda, 1931; is Vohita hilgendorfi von Martens. 1897 Although 10 Recent species, including one described herein, have been attributed to Benthovoluta (Shikama, 1971; Cernohorsky, 1973; Habe, 1976), this genus is here restricted to the four species discussed below. (Charac- teristic features of the genus include comparatively large shells with long siphonal canals, rachidian teeth with cusps limited to the central half of the tooth, and broad- Benthovoluta hilgendorfi (von Martens, 1897) (figures 1-3) Valuta hilgendorfi von Martens. 1897:176. pi. 17. fig. 1. ?Mitra plicifera Yokoyama. 1920:48. pi. 2. figs. 16a. b; Hatai and Nishiyama. 1952:215; Taki and Oyama. 1954: pi. 3. figs. 16a, b; Cernohorsky. 1972:223 (non Mitra plicifera S. V. Wood. 1848). Phenacoptygma ? kiicnse Kuroda. 1931:48. fig. 1. Benthovoluta hilgendorfi (von Martens) Kuroda and Habe, 19.50:37, pi. 5. fig. 2; Kira, 1962:92, pi. 33, fig. 3; Shikama, 1963:97, pi. 79, fig. 7; Kuroda, 1965:50; Cernohorsky. 1973; 126-127 (in part). Description: Shell (figures 1, 2) to 84 mm. solid, elon- gate, fusiform. Protoconch (figure 3) of '4 whorl, smooth, deflected from coiling axis. Transition to teleoconch abrupt, marked by thickened protoconch lip and first appearance of spiral threads and axial ribs. Teleoconch v\ ith up to 10 convex, rounded whorls. Suture adpressed. Shoulder roiuided. Spiral sculpture of incised spiral lines. 37-45 on bod\ whorl. 9-11 on exposed portions of pre- vious whorls, and 20-27 on siphonal canal. Incised lines may be thinner and shallower along siphonal canal. Axial sculpture of 12-14 costae. prominent on early whorls, rarely occurring bcv (ind 8th postiniclear w horl. .\perture elongate, elliptical Outer lip smooth, thin, porcellaneous. Inner lip smooth, glazed. (Columella solid, with 3 (oc- M. G. Harasewvch, 1987 Page 169 Table 4. Species and specimens that pro\'ided anatomical data for cladistic analyses of relationships between the subfamilies of Turbinellidae. Columbariinae Tomlin, 1928 Coluzea rotunda (Barnard. 1959), 2 9. 2 <3, SAM A 4592. off Cape Town. South Africa, 1,006-869 m Ptychatractinae Stimpson, 1865 Bcnthovoltita claydoni new species, data contained herein Turbinellinae Swainson, 1840 Turbinella angulata (Lightfoot, 1786), 2 9, 2<5, USNM 846315, off Carrie Bow Cay, Belize, 1-2 m Vasinae H. and A. Adams, 1853 Vasum muricatum (Born, 1778), 2 9, 2 ,5, USNM 846316, off Carrie Bow Caw Belize, 1-2 m Table 5. Characters and character states used in cladistic anaKses of the relationships between the subfamiles of Tur- binellidae. 1) 2) 3) 4) 5) 6) 7) 8) 9) 10) Siphon, long: exposed (a); narrow, covered (b); broad, flesh\, covered (c) Median cephalic furrow: absent (a); present (b) Retracted proboscis: linear (a); folded (b) Proboscis retractor muscles: paired (a); single (b) Lateral radular teeth: bicusped (a); monocusped (b) Rachidian teeth uith cusps spanning: > 0.75 basal plate (a); < 0.75 basal plate (b) Anal gland: present (a); absent (b) Bursa copulatrix: present (a); absent (b) Sperm groove: along inner lateral edge of penis (a); runs \'entrall>- just prior to opening (b) Penial papilla: absent (a), present (b) casionaliy 4) simple folds. Central fold most prominent, may become fused with anteriormost fold. Siphonal canal broad, tapers distally. crosses coiling axis. Interior shell surfaces smooth, except for columellar folds. Color chest- nut brown. Early whorls may be lighter. Aperture may have a whitish overglaze. Operculum reduced, thin, elon- gate, with terminal nucleus. Soft parts other than radula are unknown. The radula was figured by Habe (1952) and refigured by Rehder (1967). Type locality: Von Martens (1897:176) gave the locality as "Japan, probably from Hakodate, Hilgendorf". This is outside the range of the species, as reported by several Japanese authors (e.g.. Kira, 1962:92; Kuroda et al., 1971: 199), and probably in error. Material examined: LSXM 605772, Tosa, Japan, 274 m; USNM 612610, Japan; USNM 824942, off Choshi, Japan, Distribution: Off the eastern coast of Japan, south of Choshi (Central Honshu), in 50-300 m. Ecology: This species inhabits sandy bottoms at depths of 50-300 m. Most specimens examined had one or more repaired breaks, indicating unsuccessful predation by crabs and /or fish. Remarks: This species is readily identified on the basis of its cliestnut brown color and its spiral sculpture of incised furrows. Benthovolufa gracilior Rehder, 1967 (figures 4-6) BenthoLoluta gracilior Rehder, 1967:185, figs. 5, 6; Cernohor- sky, 1973:129. Description: Shell (figures 4, 5) to 57 mm, thin, bicon- ical, narrow 1\ fusiform. Protoconch (figure 6) of % whorl, smooth. Transition to teleoconch demarcated by abrupt appearance of axial costae and spiral threads. Teleoconch with up to 10''/4 whorls. Suture adpressed. Shoulder pro- nounced, rounded. Spiral sculpture of 42-46 fine cords on body whorl, 48-52 on siphonal canal, and 16-18 on exposed portions of earlier whorls. Fine spiral threads ma\ occur between adjacent cords, especially between shoulder and suture. .Axial sculpture of 16-18 prominent costae per whorl. Axial costae poorly defined below mid- point of body whorl. Aperture elongate, narrow. Outer lip thin, smooth. Columella solid, with 2 folds, posterior fold more prominent. Siphonal canal long, narrow, cross- es coiling axis. Periostracum thin, of straw-colored axial blades. Operculum and soft parts unknown. Type locality: Off Cagavan Islands, north Sulu Sea, Philippines. 9°38'30"N, 121°! I'E, in 929 m. "Albatross I" sta. 5423. Material examined: USNM 637252 (holotype), USNM 23S408 (4 paratypes), DMNH 15456 (paratype), all from the t\ pe locality. Distribution: Known only from the type locality. Ecology: This species was taken in 929 m on gra\ mud and coral sand bottom. Remarks: This species differs from its congeners in hav- ing a smaller, thinner, more highly spired shell, with axial ribs that are prominent on the bod\' whorl. It has only been taken once, and at twice the depth inhabited by its known congeners. Benthovohtta krigci Kilburn, 1971 (figures 7-9) Benthovohtta kngci Kilburn. 1971:127-130, figs. 2d, 3a,b; Kensley, 1973:180, fig. 686. Description: Shell (figures 7, 8) to 71 mm, solid, inflated, narrowK fusiform. Protoconch (figure 9) of % whorl, smooth, globose, de\iated from coiling axis. Transition to teleoconch marked by abrupt appearance of numerous fine spiral threads and strong axial ribs. Teleoconch w ith up to 9% convex, rounded whorls. Suture strongly ad- pressed in early whorls, whorls abutting in larger spec- imens. Shoulder weak, rounded. Spiral sculpture of broad. Page 170 THE NAUTILUS, Vol. 101, No. 4 M. G. Harasewvch, 1987 Page 171 12 Figures 1-3. Benthovoluta hilgendorfi (von Martens. 1897), 1. USNM 824942, off Choshi, Japan. 2. USNM 605772. Tosa, Japan, in 274 m. 3. Protoconch of specimen in figure 1. Figures 4-6. Benthovoluta gracilior Relider, 1967- 4. Holot>pe, USNM 637252. 5. Paratype, USNM 238408, both from off Cagayan Islands, northern Sulu Sea, Phihppines, in 928 m. 6. Protoconch of specimen in figure 5. Figures 7-9. Benthovoluta krigei Kilburn, 1971. 7, 8. USNM 824943. off Inhaca Island, Mocambique, trawled in 475 m. 9. Protoconch of specimen in figure 7 Figures 10-12. Benthovoluta claydoni new species. 10. Holotype, WAM 3252-83. 11. Paratype 1, USNM 862217, both from SW of Imperieuse Reef, Rowley Shoals, Western Australia, 400-401 m. 12. Operculum of holotype, left— inner surface, right- outer surface. All shells 1.25 x, protoconchs 30.0 x, operculum 3.0 x. rounded, closely-spaced cords that give shell surface a deeply incised appearance, 36-48 on body whorl, 20-23 on penultimate whorl, 13-19 on siphonal canal. Axial sculpture of 12-16 costae, prominent on early whorls, becoming reduced and generally absent b\ 6th postnu- clear whorl. Aperture elongate, narrow . Outer lip thin, strongly sinuate posteriorly. Inner lip smooth, with shell surface dissolved to below level of spiral sculpture. Col- umella solid, folds weak or lacking. Siphonal canal long, broad, distalK tapering. Interior shell surfaces smooth. Color light tan, with darker brown between suture and shoulder, along the anterior half of the body whorl, distal portion of the siphonal canal, and in a thin band along the margin of the outer lip. Periostracum unknown. Operculum as in B. hilgendorfi (fide Kilburn, 1971). Kilburn (1971:129) described the animal as white, with thin, filiform tentacles with e\es at the outer sides of their bases. Radula (Kilburn, l'971:129, fig. 2d) with 69 rows of teeth. Rachidian teeth tricuspid, with broad, arcuate base. Lateral teeth monocuspid, claw-like. Type locality: 80 km due east of Inhaca Island, Mo- cambique, in .512 m (280 fm). Material examined: USNM 824943, off Inhaca Island. Mocambique, in 475 m. Distribution: This species has onK been taken off Inhaca Island, Mocambique at depths of 475-512 m. Remarks: Kilburn (1971:129) considered this species to more closely resemble Surculitia than any species of Ben- Page 172 THE NAUTILUS, Vol. 101, No. 4 M. G. Harasewych, 1987 Page 173 Figures 13-18. Benthovohita claydoni new species. 13. Periostracum, scale bar = 300 nm. 14. Shell ultrastructure, fracture surface parallel to growing edge, scale bar = 200 iim. 15. Parietal area of columella, showing reabsorption of portion of outermost shell layer, scale bar = 100 nm. 16. Section through columella perpendicular to shell axis, surface polished and acid-etched (1% HCl). Arrow indicates limit of shell reabsorption, scale bar = 200 jum. 17. Rachidian teeth, scale bar = 30 ij.m. 18. Radular ribbon, scale bar = 50 ^m Figure 19. Radular ribbon of Ptychairactus ligatus (Mighels and Adams, 1842), scale bar = 30 ^m. Figure 20. Radular ribbon of Cyomesits chaunax (Bayer, 1971), scale bar = 20 ^m. Figure 21. Radular ribbon of Turbinella pyrum (Linne, 1758), scale bar = 30 ^m. Figure 22. Radular ribbon of Vasiim muricatum (Born, 1778), scale bar = 50 nm thoioluta in shell morphology, but assigned it to the latter genus because Dal) (1908:292) reported that Siir- culina cortezi (Dall, 1908) lacked e\es, tentacles, and operculum, and due to a misinterpretation of Rehder's (1967: fig. 10) figure showing two views of a monocuspid lateral tooth as a bicuspid lateral tooth. .Although the relationship between Benthovohita and Surculina bears closer investigation when anatomical material becomes available, Benthovohita krigci is more closeK related to its Indo-Pacific congeners than to any species of Siir- cuhna. Examination of additional specimens of 6. krigei revealed that several had weak but nevertheless distin- guishable columellar folds corresponding to the ante- riormost two folds of B. hilgcndorfi. Benthovoluta claydoni new species (figures 10-18, 2;3-26; table 6) Description: .Shell (tigures 10, 11) to 101 mm. solid, elongate, fusiform. Protoconch broken or abraded on all Page 174 THE NAUTILUS. Vol. 101, No. 4 Table 6. Berithovolula claydoni new species Measurements ot shell eharaelers. Linear measurements in mm Character .V Range SD Shell length (SL) 85.0 62.2-100.9 9.4 .Aperture + siphonal canal length (.\ + SCL) 5L0 .35.2-60,3 6.6 .•\ + SCL SL 0.599 0.566-0.622 0.018 # Whorls 10.3 8-13 1,4 Spire angle 29,1 25.5-32.0 2,4 specimens examined. Teleoconcli w ith up to 13 slight!} convex whorls. Suture adpressed. Shoulder somewhat pronounced on early whorls, becoming more rounded with increasing size. Spiral sculpture of weak, simple cords, 33-42 on body whorl, 12-18 on exposed portions of earlier whorls, 15-35 on siphonal canal. Cords stron- gest between shoulder and siphonal canal, weakest at suture and distal portion of siphonal canal. Axial sculp- ture of 9-11 costae, most pronounced on earlier whorls, becoming reduced and usually absent by 7th postnuclear whorl. Aperture elongate, elliptical. Outer lip smooth, thin, porcellaneous. Inner lip smooth, characterized by dissolution of portion of outermost shell layer from pa- rietal region (figures 15, 16). Columella solid, with 3 simple folds, central fold most prominent, posteriormost fold weakest and sometimes absent. Siphonal canal broad, long, crosses coiling axis. Interior shell surfaces imiformly smooth, unmodified except by columellar folds. Perios- tracum (figure 13) of short, thin, straw-colored, axial blades. Operculum (figure 12) greatly reduced (< 0.4 x aperture length), thin, elongate, terminally nucleated. Ultra-Structure: Shell of two orthogonal layers of crossed- lamellar aragonite (figure 14). Outer layer, 420-620 ^m thick, w ith crystal faces colabrally aligned. Inner layer, 320-350 M'li thick, with crystal faces perpendicular to growing edge. Spiral sculpture limited to outer layer, columellar folds comprised of inner layer. Portion of outer layer along parietal area dissolved to below level of spiral sculpture (figures 15, 16), indicating boundary of inner lip. External anatomy: Soft parts comprise 4'/2 whorls. Man- tle cavity extends over 1 whorl, kidney spans V2 whorl, digestive gland 2V2 whorls. Foot short, narrow (L/W = 2.0), squarish anteriorly, rounded posteriorly. Opercu- lum as broad as foot. Preserved animals khaki tan in color, lack discernible color pattern. Siphon broad, mus- cular, simple. Head small, narrow, with long tentacles (figure 25, t) that have large, black eyes (figure 25, e) at their outer bases. Mantle cavity: Mantle cavity organs similar to those of Fulgurofusus brayi ((blench, 1959), as described by Ha- rasewych (1983). Mantle edge slightly thickened, finely papillose. Osphradium large, long (L/W = 4.3), consist- ing of about 70 triangular filaments above and 60 below the axis. Ctenidium of about 200 deep hanging leaflets, 1.9 X as long and 1.0 x as wide as osphradium. Hy- pobranchial gland trans\ersel\ pleated, deepK- glandu- lar, unpigmented. Rectum and genital ducts along right side of mantle ca\ ity, large pericardium and kidney along its back wall. Alimentary systcnj: Rhynchostome opens at base of tentacles, leads to short, muscular, pleurembolic probos- cis (figure 23, p). Single, large proboscis retractor muscle attaches to right w all of cephalic hemocoel and surrounds a large blood vessel. Buccal cavitv (figure 23, bcv) deep, with strong longitudinal folds, lacks jaws. Buccal mass (figure 23, bm) large, muscular, projects beyond rear of retracted proboscis. Radular sack short, contained within buccal mass. Radular ribbon (figure 18) short (4 mm), narrow (300 fim). contains 88-97 rows of teeth (n = 3). Rachidian teeth (figure 17) with three cusps emanating from middle half of tooth. Basal plate recur\ed, narrow. Lateral teeth with single, trowel-like cusp. Esophagus runs anteriorK from rear of proboscis, expanding to form large valve of Leiblein (figure 23, vl) before passing through nerve ring. Salivary glands (figure 23, sg) asym- metrical, situated at rear of retracted proboscis. Ducts from salivar\ glands join esophagus just anterior to the valve of Leiblein, become embedded beneath the dorsal folds. Accessory salivar\ glands absent. Between nerve ring and duct from gland of Leiblein (figure 23, dgl), esophagus expands and becomes glandular, resembling a "glande framboisee' (Fretter & Graham, 1962:216). Gland of Leiblein (figure 23, gl) large, brownish, broad anteriorly, tapering posteriorh' to form blind ampulla, fills posterior half of cephalic hemocoel. Posterior esoph- agus (figure 23. pe) runs along left side of gland of Leib- lein, expanding along anterior face of digestive gland (figure 23, dg) to form stomach. Stomach (figure 23, sto) ll-shaped, with small caecum, prominent typhlosoles. Duct from digestive gland enters near esophageal open- ing. Intestine (figure 23. int) short. Rectum (figure 23, r) broad, thin-walled, \oluminous. Rectal gland (figure 23, rg) spans dorsal, distal V4 of rectum. Anus (figure 23, a) simple, pendant from wall of mantle cavity. Female reproductive system: Ovar>' salmon colored, ascinous, lines adapical side of digestive gland. Oviduct (figure 24. od) thin, passes through kidne\. runs along pericardial w all before joining pallial o\ iduct at juncture of albumen gland, capsule gland, and duct of ingesting gland, .\lbumen gland (figure 24, ag) short, lateralK com- pressed, forms anterior portion of right wall of kidney. Ingesting gland (figure 24, ig) small, whitish, with long duct. Capsule gland (figure 24, eg) long, narrow, divided into proximal and distal regions by transverse ridge \ is- ible along outer w all as narrow, light colored band. Bursa copulatrix (figure 24, be) ovate, abutts against capsule gland, laterally compressing its anterior end. Female opening (figure 24, fo) ventral slit along anteriormost enil of bursa copulatrix. Male reproductive system: Testis (figure 25, te) pale orange, situated along adapical side of digestive gland. ■JVsticular duct (figure 25. td) runs anteriorly, expands and becomes couNoluted. forming seminal vesicle (figure M, G. Harasewvch, 1987 Page 175 sv Figures 23-26. Anatomical features of Benthovoluta claydoni new species. 23. Alimentar\' system, 24. Female pallial oviduct. 25. Male reproductive system, 26. Ventral view of penis tip. a, anus; ag, albumen gland; be, bursa copulatrix; bcv, buccal cavity; eg, capsule gland; dg, digestive gland, dgl, duct of gland of Leiblein; e, eye; fo, female opening; gl. gland of Leiblein, ig, ingesting gland; int, intestine; od, oviduct; p. proboscis; pe, posterior esophagus; pen, penis; r, rectum; rg, rectal gland, sg, salivary gland; sgr, sperm groove; sto, stomach; sv, seminal vesicle; t, tentacle; td, testicular duct; te, testis; vl, valve of Leiblein. 25, sv) along anterior portion of kidney and pericardium. Duct straightens, enters rear of mantle cavity and runs anteriorly along its wall, ventral to rectum, descending to floor of mantle cavity at midlength to form muscular, open groove (figure 25, sgr). Groove runs anteriorly to base of long, dorsoventrally compressed, distally tapering penis (figure 25, pen), and along its inner lateral edge to the distal end, where it passes along the ventral surface and extends to tip of papilla (figure 26, pap), situated in a concavity at the outer distal edge of penis. Page 176 THE NAUTILUS, Vol. 101, No. 4 Kidney: Kidney large, w itli broad nepliridial gland ad- jacent to pericardium and about 10 hea\il> pleated la- mellae emanating trom tlorsal and lateral walls. Etymology: This species honors Michael CilaNclon, ot Port Hedland, Western Australia, who first brought it to my attention, and generously provided material for study. Type locality: SW of Imperieuse Reef, Rowle)' Shoals, Western Australia, 18°05'S, 1 18°10'E, in 400-401 m, mud bottom. Holotype: Western Australian Museum WAM 3252-83, (5, length 84.7 mm. Paratypes: Paratypes 1-2, National Museum of Natural History, Smithsonian Institution USNM 862217, para- types 3-4, WAM 3252-83, all from the type locality; paratype 5, WAM 972-84, WNW of Lacepede Archi- pelago, Western Australia, 15°40.2'S, 120°37.3'E to 15°42.6'S, 120°34.6'E, in 500-504 m, soft bottom; para- tvpe 6, W.AM 977-84, W of Cape Leveque, Western Australia, 16°09.5'S, 120°08.8'E to 16°07.6'S, 120°10.0'E, in 600-596 m, soft bottom; paratype 7, WAM 990-84, W of Broome, Western Australia, 17°59'S, 118°11'E to 18°01'S, 118°08'E, in 530-560 m, soft bottom; paratype 8, WAM 1556-84, WNW of Lacepede Archipelago, Western Australia, 15°46.4'S, 120°39.9'E to 15°43.8'S, 120°39.8'E, in 446-450 m, soft bottom; paratype 9, WAM 1564-84, WNW of Lacepede Archipelago, Western Aus- tralia, 15°51.2'S, 120°44.3'E to 15°49.3'S, 120°45.3'E, in 350-348 m, soft bottom; paratvpe 10, WAM 1866-84, W of Lacepede Archipelago, 16°55.4'S, 119°52.3'E to 16°57.4'S, 119°46.4'E, in 436-448 m, soft bottom; para- types 11-12, WAM 1908-84, W of Lacepede Archipel- ago, Western Australia, 16°57.4'S, 119°52'E to 16°55'S, 119°56'E, in 434-432 m, soft bottom; paratype 13, WAM 1160-85, W of Lacepede Archipelago, Western Australia, 16°55.2'S, 119°50.9'E to 16°56.3'S, 119°54.8'E, in 430- 436 m, soft bottom; paratvpe 14, USNM 862218, NW of York Sound, Western Australia, 12°54.4'S, 123°00.2'E to 12°50.6'S, 123°00.4'E, in 452-462 m, soft bottom; para- tvpe 15, WAM 1681-84, NW of Collier Bay, Western Australia, 13°44'S, 122°13.3'E to 13°22.3'S, i22°14.7'E, in 496-494 m, soft bottom; paratypes 16-17, USNM 845602, 30-60 miles SW of West Island, Rowley Shoals, Western Australia, 250-430 m; paratype 18, American Museum of Natural History, AMNH 221361, off Port Hedland, Western .Australia, in 450 m. Distribution: All specimens examined in this study were taken along the upper continental slope off northern Western Australia at depths of from 350 to 596 m. The mean station depth was 453 m (n = 15). Ornohorsk\ (1973) figured and described a single, male specimen of this new species [as Bcnthovoluta hilgendorfi (von Mar- tens, 1897)] from the C'elebes Sea, 25 miles east of Zam- boanga, Philippines, in about 450 m. Ecology: Benthovolitta vlaijduni occurs on mud and soit bottoms at depths Irom 350 to 596 m. Live collected specimens had a thin or worn periostracum, yet lackcil epizoans, suggesting that this species ma\ be an infaunal l)urrower. Numerous repaired breaks in a majorit) of the specimens examined, indicate frequent, unsuccessful predation by crabs and/or fish. Contents of the alimen- tary systems of three individuals were examined, one stomach contained fragments of an amphipod carapace. No polychaete setae were found in the guts of any of these specimens. Comparative remarks: Benthocoluta claijdoni most closely resembles the Japonic B. hilgendorfi (von Mar- tens, 1897), which can be distinguished from B. claydoni by its chestnut brown color, spiral sculpture of incised furrows, and more pronounced axial sculpture, Ben- thovoluta krigei has a narrower, more fusiform shell with more evenly convex whorls, weaker axial sculpture that gives the body whorl a finely cancellate appearance, is tan in color with two to three darker spiral bands, and lacks or has very weak columellar folds. Benthovolitta gracilior Rehder, 1967, from somewhat deeper waters 928 m) of the Sulu Sea, differs from this new species in being smaller and more fusiform, and in having stronger axial sculpture that is not limited to the early whorls. DISCUSSION The genus Benthovolitta. as restricted above, is limited to the continental slopes along the margins of the Indian and western Pacific oceans in the Recent fauna. Fossil records are limited to the Pliocene of Japan (Yokoyama, 1920; Taki & Oyama, 1954) and the late Miocene or earl\ Pliocene of Okinawa (MacXeil, 1960), and are all from bathyneritic or bath)al depths. Of the Okinawan fossil species, Benthovoluta okinavensis MacNeil, 1960 is here reassigned to the genus Cyomesus on the basis of its small size, short siphonal canal, absence of spiral sculp- ture, prominent axial ribs, and overall resemblance to Cyomesus harthelowi (Bartsch, 1942). However, the fragments illustrated as Phenacoptygma new species (MacNeil, 1960: pi. 9, figs. 4, 5), are referable to the genus Benthovolitta. and represent the oldest known rec- ord for the genus. Phenetically deduced relationships between the species of Benthovolitta based on UPGMA and single linkage clustering using the data in table 7 are shown in figure 27. Both algorithms produced dendrograms with iden- tical topologies. Closest relationships are between the eastern Indian-western Pacific species, which differ in geographic and (B. hilgcndorfi-B. elaydoni) i or (B. clay- doni-B. graeUiur) batlnnietric distributions. Several ex- amples of similar bathNmetric zonation have been reported in the bathyal turbinellid subfamily Colum- bariinae, along with the suggestion that such bath\ metric speciation occurreil as a result of sea le\ el changes during the Cenozoic (Harasewych, 1986). In contrast to the zoo- geographic patterns seen in the Columbariinae, where there is considerable divergence between Indian and Pa- cific ocean species, and close similarity between eastern and western Indian Ocean taxa (Harasew \ch, 1986), Benthovoluta claydoni. which occurs in comparable M. G. Harasewvch, 1987 Page 177 depths, spans both oceans, ranging trom off Western Australia to the Phihppines. Dendrograms showing UPGMA and single linkage clustering of the Recent genera included in Ptychatrac- tinae, based shell and radular ciiaracters (table S), are shown in figure 28. In each instance, the genera Cera- toxancus and Latiromitra are clustered together and differentiated from the other genera referred to Pt\ cha- tractinae. Although originally described in the family Turbinellidae, several authors have commented on the affinities of Ceratoxancus to the Mitridae (Sakurai, 1957) or Volutomitridae (Cernohorsky, 1973). The radulae and protoconchs of the two species in this genus are unknown. Prior to Bouchet and Waren's (1985) reassignment of Latiromitra to Pt\chatractinae on the basis of overall coiichological similarity to Cyomesus. this genus had been included in the families Buccinidae (Locard, 1897), Costellariidae (Thiele, 1929), and Volutomitridae (Cer- nohorsk>, 1970). The radula of this monot\pic genus is unknown. Bouchet and \\'aren (1985:255) commented on the multispiral protoconch of the t> pe species, and suggested its larvae are planktotrophic. All members of the famiK Turbinellidae for which developmental data are available undergo direct de\elopment (Bandel, 1975a, b), and ha\e large, bulbous, although occasionally multispiral, protoconchs (Vasinae — Abbott, 1959; Col- umbariinae — Darragh, 1969; Harasewych, 1983, 1986; PtNchatractinae — Bouchet & Waren, 1985; herein; Tur- binellinae — Bandel, 1975b). Other than superficial con- chological similarity, there is little evidence for inclusion of either of these genera in the family Turbinellidae. Determination of their true phylogenetic affinities will recjuire anatomical and radular data. The remaining genera have been referred to the Pty- chatractinae on the basis of conchological as well as rad- ular features. The close relationships between Bentho- voluta and Siircitlina have been noted pre\iously (Rehder, 1967; Kilburn, 1971). Although similar in shell mor- phology, these genera differ substantialK in size (Sur- culina rarely exceeding 40 mm in length), bathy metric UPGMA B. fiilgendorfi B. claydonl B. gracilior B. krigei 2.0 1.5 1.0 0.5 0.0 SINGLE LINKAGE B. hilgendorfi B. claydonl B. gracilior B. krigei Figure 27. PheneticalK deduced relationships between species in the genus Bcnthovoluta. produced b\ L PGMA (upper) and single linkage (lower) clustering of Euclidian distances between ta.xa, calculated using standardized data. distribution (with a single exception Siirculina inhabit depths in excess of 1,000 m), and geographic distribution (Siirculina are known onl)' from New Zealand and the eastern Pacific). Dall (1908) reported that the animal of S. cortczi (Dall, 1908) lacked eyes, tentacles and oper- culum. Although tiie loss of eyes is not uncommon in deep water gastropods (Knudsen, 1973; Harasewych, 1987), the absence of tentacles and opercula in these animals is enigmatic. Both clustering algorithms produced identical den- drograms of the relationships between the remaining small-shelled genera. Cyomesus, which is here regarded as distinct from Latiromitra, is the only Ptychatractine genus to have Recent representatives in the western At- lantic and western Pacific oceans. In his description of this genus, Quinn (1981:76) raised the possibility that the western Pacific representatives, which now include Cyo- Table 7. Measurements of shell characters in the format mean/standard deviation. .All linear measurements in mm. Mean values constitute the data matrix for phenetic analyses or relationships between Bcnthovoluta species. Character hilgendorfi claijdoni n = 5 gracilior n =5 krigei n = :3 1) Sbc 2) Ssc 3) Rsl 4) beta 5) theta 6) W 7) D 8) T 9) A -t- 10) CP 11) C SLC/SL 12) Sut 1.3) Sculp 2.75/0.01 2.88/0.10 2.63/0.17 3.24/0.11 4.26/0,28 3.96/0.80 6.05/0.12 4.57/0.18 0.68/0.06 0.68/0.04 0.99/0.11 0.70/0.10 -1.6/1.4 -2.5/1.2 4.1/1.4 1.3/2.8 12.2/2.2 11.5/1.4 11.9/0.6 11.4/0.3 1.38/0.02 1.49/0.03 1.47/0.01 1.58/0.05 0.18/0.04 0.22/0.04 0.17/0.00 0.15/0.05 7.64/0.36 7.50/0.47 8.43/0.55 9.14/0.67 0.578/0.008 0.596/0,004 0,547/0,012 0.567/0.019 0.0 0.0 0,0 1.0 1.0 0.0 0,0 1,0 0.0 0 0 0,0 1,0 0.0 0,0 (10 1 0 Page 178 THE NAUTILUS, Vol. 101, No. 4 UPGMA ■+■ -4- 2.0 1.5 1.0 SINGLE LINKAGE 0.5 r[ Benthovoluta Surculina Metzgeria Gyomesus Ptychatractus Liromitra Ceratoxancus 0.0 Benthovoluta Surculina Metzgeria Gyomesus Ptychatractus Latiromitra Ceratoxancus Figure 28. Phenetically deduced relationships between genera assigned to the subfamiK Ptychatractinae, pioducedhy UPGMA (upper) and single linkage (lower) clustering of Euclidian dis- tances between taxa, calculated using standardized data. rnesiis barthelowi (Bartsch, 1942), C. delicatula (Shi- kama, 1971), C. sakashitai (Habe, 1976), and C. naka- yasui (Habe. 1976), miglit be separable into a separate subgenus. Most closely related to Cyomesus, or at least to its western Atlantic type species, is Metzgeria, from the bathyal zone of tfie northeastern Atlantic. These gen- era have ver)' similar shell and radular morphologies as well as bathymetric ranges. Although several additional, Table 9. Character state distributions of anatomical characters listed in table 5 among the subfamilies of Turbinellidae. COL = Columbariinae; PTY = Ptychatractinae; TUR = Turbinellinae; \'AS = Vasinae Character COL PTY TLR \AS 1) b c c a 2) a a b a 3) b a b a 4) b b b a 5) a a a b 6) a a a b 7) a a a b 8) a a b a 9) a b a a 10) a b b a geographicalK remote, species have been described in the genus Metzgeria, their generic assignments are con- sidered either speculative (M. calif orr^ica Dall, 1903; M. motitereyana Smith and Gordon, 1948), being based on vague conchological similarities, or erroneous (A/, apo- dema Bouchet and Talavera, 1981) b\ virtue of ha\ing a multispiral larval shell. More remotely related to both these taxa is Ptychatractus, the type genus of the subfam- ily. Similar to both genera in size and shell morphology, it is characterized by prominent spiral sculpture and by a radula that has features of Cyomesus as well as of Benthovoluta (figure 19). Although fossil representatives of most of the Recent genera are unknown, a number of Cretaceous and Eocene genera have been regarded as possible members of the Ptychatractinae (Quinn, 1981). Examination of several specimens of the type species of Paleofusimitra Sohl, 1963 and Fusimitra Conrad, 1855 revealed only super- ficial similarity in shell form with an\- member of the Ptychatractinae. The similarity of the single known spec- imen of the Cretaceous genus Mitridomus Sohl, 1963 to Latironutra had been noted b\ Sohl, 1964; however, resolution of the question of whether Mitridomus rep- Table 8. Measurements of shell characters used in phenetic assessment of the relationships of the Recent genera assigned to the subfamily Ptychatractinae. All linear measurements are in mm. BEN = Benthovoluta. CER = Ceratoxancus. CYO = Cyomesus. LAT = Latiromitra. MET = Metzgeria. PTY = Ptychatractus. SVW = Surculina. Character BEN CER CYO LAT MET PTY SUR 1) Sbc 2.75 2.67 2.23 2.17 2.00 1.63 2.44 2) Ssc 4.26 2.02 2.71 2.00 2.78 2.23 3.11 3) Rsl 0.68 0.41 0.72 0.41 0.60 0.50 0.73 4) beta -1.6 -16.3 -4.1 -13.5 -4.8 -11.2 -0.5 5) theta 12.2 18.5 16.1 10.2 16.0 18.8 11.4 6) W 1.38 1.49 1.42 1.51 1.73 1.69 1.67 7) D 0.18 0.32 0.15 0.27 0.15 0.18 0.19 8) T 7.64 5,36 6.94 5.93 6.25 5.35 5,99 9) A -1- SLC/SL 0.58 0.55 0.59 0.47 0.54 0.51 0.60 10) Prot 1.0 ? 1.0 0.0 1.0 1.0 1.0 11) Lat 1.0 ? 0.0 ? 0.0 1.0 1.0 12) Rachl 1.0 ? 0.0 ? 0.0 1.0 1.0 13) Rach2 1 0 0 0.0 3 00 00 1 0 M. G. Harasewvch, 1987 Page 179 Figure 29. Recent geographic tlistribution ot genera assigned to the subfamiis Pt>chatractinae. Open stars = Cyomesus: closed stars = PtiichalracUis. open circles = Surculina. closed circles = Benthovoluta, open triangle = Ceratoxanciis; closed triangles = LatironUIra, stippled area = Mctzgcria, resents an earK ptxchatractine, and LatirouiHra a Re- cent descendant that retained a multispiral protoconch. or whether both genera had previously been correctly assigned to the faniiK Mitridae, must await the avail- abihty of anatomical material of Latiromitra. Several species of the genus Mcsorhytis Meek, 1876 from the Upper Cretaceous of the United States bear strong re- semblance to Recent Benthovoluta, althougli the\ are smaller in size (about 30 mm). Mcsorhytis dakotacnsis Stanton, 1920 from Paleocene deposits of North Dakota, more closely resembles Cyomesus. and had a paucispiral protoconch. "Fasciolaria" assimilis Stoliczka, 1868 from the Upper Cretaceous of southern India, bears unmis- takable resemblance to Recent species ot Benthovoluta. and had attained a size of 140 mm. As inclusion of even Recent species in the Ptychatractinae on purely con- chological characters is uncertain, the assignment of Cre- taceous genera to this group must remain tentative. The geographic distribution of the Recent genera of Ptychatractinae (figure 29) indicates that, with the single exception of Latiromitra. a monot\pic genus with plank- tonic larvae cjuestionabK included in Ptychatractinae. all are restricted to continental margins or their adjacent abyssal plains. The distribution of the genus Surculina indicates that this group evolved in the Austral Province (Kauff man, 1973), prior to the separation of New Zealand at the end of the EarK Paleocene, and is an offshoot of east Teth\an Benthovoluta or its precursors. The closing of the Tethv s Sea at the end of the Eocene separated the Atlantic and Pacific species of the genus Cyomesus. The close resemblance of Metzgeria to the western .Atlantic type species of Cyomesus suggests that Metzgeria is an offshoot from the west Tethyan branch of that genus. The origin of the genus Ptychatractus is more obscure. One possibilit\ is that it di\ erged from the east Teth% an (western Pacific) branch of Cyomesus. evolved in the northern Pacific, w ith one branch extending southward along the w estern coast of North America, while another w as part of the late Pliocene Beringean Transgression of Pacific boreal mollusks through the Bering Strait, across the .\rctic, and into the North Atlantic (Durham 6c MacNeil, 1967; Nelson. 1978). The relationship of La- tiromitra to the Cretaceous Mitridomus has been dis- cussed pre\iousl\ . The affinities of Ceratoxancus are un- certain. If it is indeed a pt\chatractine, it ma\' be an offshoot of any of the eciualK cjuestionable. mitriform. Cretaceous turbinellids. Dissections of Benthovoluta claydoni new species re- vealed a basically turbinellid anatomical organization that most closeK resembled Turbinella angulata in most features of the shell, mantle cavity, and alimentary and male reproductive systems, and Coluzea rotunda in fea- tures of the female reproductive system. The short mus- cular proboscis and torted, papillate penis, also found in Cyomesus chaunax, distinguish these taxa from all other turbinellids, and may prove to be diagnostic of the subfamily Ptychatractinae. The presence of an amphi- pod carapace in one stomach, as well as an absence of poKchaete setae from the guts of all three of the spec- imens examined, suggest a diet different from that re- ported for the other subfamilies within Turbinellidae. The pin logenetic relationships of the four subfamilies Page 180 THE NAUTILUS, Vol. 101, No. 4 UJ < z CO < > < HI 7 o < < z DC a: 1- m < Hi s X z q o CO > oc o t- 3 o a. f: Figure 30. Cladograms indicating the relationships between the subfamihes of the faniiK Turbinelhdae, based on characters in table 5. of Turbinelhdae, as deduced from an analysis of the taxa in table 4 scored for the characters in table 5, are shown b> the cladogram in figure 30. This cladogram, with a consistency inde.x of 0.917, indicates that the subfamily Ptychatractinae is most closely related to the Turbinel- linae, and that divergence between the Vasinae and the remaining subfamilies is the most ancient. This ph\'lo- genetic arrangement is at least partially supported by the fossil record, as the subfamilies Vasinae, Columba- riinae, and Ptychatractinae all have Cretaceous repre- sentatives (VVenz, 1943; Darragh, 1969; herein), while earliest records of Turbinellinae date trom the Lower Eocene (Vokes, 1964). ACKNOWLEDGEMENTS I thank Michael Claydon and Richard E. Kurz for first making specimens of the new species available, and to Dr. F. E. Wells, of the Western Australian Museum for providing additional specimens, including preserved ma- terial. Additional specimens of Benthuvultita were loaned by Dr. W. K. Emerson, of the American Museum of Natural History and Mr. R. H. Jensen, of the Delaware Museum of Natural Histor\ . The assistance of Ms. S. Ikaden and Mr. B. Kahn with the scanning electron microscopy and Ms. Molly Kelly Ryan with illustration is gratefully acknowledged. 1 am indebted to Mr. R. (Chapman for assistance w ith SYSTAT, and to Dr.s. R. S. Houbrick, and H. A. Relider for critical readings of drafts of this manuscript. LITERATURE CITED -Pacific Abbott, R. T. 1959. The family X'asidae in the Indo Indo-Pacific Mollasca 1(1): 15-32 liandel, K. 1975a. Ernbryonalgehause karibischer Mcso- und Neogastropoden (Mollusca). .Abhandlungen der Mathe- matisch-Natiirwissenschaftlichen Klasse Jahrgang 1975, .\kademie der Wissenschaften und der Littratur, Mainz 1:4-133. Bandel, K. 1975b. Entwicklung der Schale im Lebensablauf zweier Gastropodenarten; Buccintim undatum und Xan- cits angulatus (Prosobranchier, Neogastropoda). Biomi- niralisation 8:67-91. Bandel, K. 1984. The radulae of Caribbean and other Me- sogastropoda and Neogastropoda. Zoologische \'erhande- lingen 214:1-188. 22 pis. Bartsch, P. 1942. Some deep-sea Philippine volutids The Nautilus 56(1):9-13. Bayer, F. M. 1971. New and unusual mollusks collected by R/V JOHN ELLIOTT PILSBURV and R/V GERDA in the tropical western Atlantic. Bulletin of Marine Science 21(1): 11 1-236. Bouchet, P. and F. G. Talavera. 1981. Anew Met zgeria from northwest Africa. Bollettino Malacologico 17:177-180. Bouchet, P. and A. Waren 1985 Revision of the Northeast Atlantic bathyal and abyssal Neogastropoda excluding Turridae (Mollusca, Gastropoda). Bollettino Malacologico, Supplement 1, 296 p. Cernohorsky, \V. O. 1970. Systematics of the families Mitri- dae and Volutomitridae. Bulletin of the .Auckland Institute and Museum 8:1-190, Cernohorsk), VV. O. 1972. .A taxonomic evaluation of Recent and fossil non-mitrid species proposed in the famiK Mit- ridae (Mollusca: Gastropoda). Records of the .Auckland Institute and Museum 9:205-229. Cernohorsky, W. O. 1973. The taxonomy of Benthovoluta hilgcndurfi (von Martens) and allied turbinellid genera (Mollusca: Volutacea). Records of the Auckland Institute and Museum 10:123-131. Chapman, R. E., M. G Harasevvych, and R. Hershler. 1987. CONCH: an interactive computer program for the analysis of shell coiling parameters. Smithsonian Institution. Wash- ington, DC. Prerelease version. Clench, W. J. 1959. The genus Columbarium in the western Atlantic. Johnsonia 3(39):330-331. Conrad, T. A. 1855. Observations on the Eocene deposits of Jackson, Mississippi, with descriptions of thirtv-four new species of shells and corals Proceedings of the .Academy of Natural Sciences of Philadelphia 7:257-263. Dall, W. H. 1903. A new species of Metzgeha. The Nautilus 17(5):51-52. Dall, W. H. 1908. Reports on the dredging operations off the west coast of Central .America . . . by the U.S. Fish Com- mission steamer "Albatross" .... Bulletin of the Museum of Comparative Zoology 43(6):205-487, 22 pis. Dall, \V. H. 1918. Changes in and additions to molluscan nomenclature. Proceedings of the Biological Society of Washington 31:137-138. Uarragh, T. .A. 1969. A revision of the familv Columbariiilae (Mollusca: Gastropoda). Proceedings of the Roval Society of \ictoria83(l):63-119. Durham, J. VV. and F. S. MacNeil. 1967. Cenozoic migrations of marine invertebrates through the Bering Strait region. /;(. Hopkins, D. M. (ed.). The Bering Land Bridge. Stan- ford University Press, Stanford. C.A, p 326-349 Fretter, V. and .A. Graham. 1962. British prosobranch mol- luscs. Ray .Societv, London, 755 p. Habe, T. 1952. Pholadomvidae, Clavagellidae, Pandoridae, Juliidae and Cnndv locardiidae in Japan. Illustrated Cat- alogue of Japanese Shells 18:121-132. M. G. Harasewych, 1987 Page 181 Habe, T. 1976. Two new species of the genus Bcnthovoluta Kuroda et Habe from tlie western Pacific. N'enus 35(3): 97-100 Harasew\ch, M. G. 1982. Mathematical motlelingof the shells of higher prosobranchs. The Bulletin of the .-Vnierican Mal- acological Union, Inc. 1981:6-10. HarasewNch, M. G. 1983. A review of the Cxilumbariinae (Gastropoda: Turbinellidae) of the western Atlantic with notes on the anatom\ and systematic relationships of the subfamily. Nemouria 27:1-42. Harasewych, M. G. 1986. The Columbariinae (Gastropoda: Turbinellidae) of the eastern Indian Ocean. Journal of the Malacological Society of Australia 7(3--l):155-170. HarasewNch, M. G. 1987. Tractolira germonae, a new abyssal Antarctic volute. The Nautilus 101(1 ):3-8, Hatai, K. and S. Nishiyama. 1952. Checklist of Japanese Ter- tiary Marine MoUusca. The Science Reports of the Tohoku University, Sendai, Japan. Second Series (Geology) Special Volume 3, 464 p. Hornell, J. 1914. The sacred chank of India, a monograph of the Indian conch (Turbinella pijrum). Madras Fisheries Bulletin 7:1-181. Kauffman, E. G. 1973. Cretaceous BivaKia. In: Hallam, .A. (ed.). Atlas of palaeobiogeographv . Elsevier, Amsterdam, p. 353-383. Kensley, B. 1973. Sea-shells of South Africa Gastropods. Mas- kew Miller, Ltd., Cape Town, 236 p. Kilburn, R. N. 1971. Notes on some deep-water Volutidae, Turbinellidae and Turridae chieQy from off Southern Mo- cambique and Natal, with descriptions of two new species (Mollusca: Gastropoda). Annals Natal Museum 21(1):123- 133. Kira, T. 1962. Shells of the western Pacific in color. Hoikusha Publishing Co., Ltd., Osaka, 224 p. Knudsen, J. 1973. Ciiivillea alabastrina (Watson, 1882), an abvssal volutid (Gastropoda: Mollusca). Galathea Report 12:127-131, pi. 18. Kuroda, T. 1931. Two new species of Volutacea. Venus 3(1): 45-49. Kuroda. T. 1952. On an interesting new genus of gastropod Mollusca from the sea off Kii Peninsula. Publications of the Seto Marine Laboratory 2(2):29-31, Kuroda, T. 1965. On the generic position of Bcnthovoluta (Gastropoda). Venus 24(l):50-52. Kuroda, T. and T. Habe. 1950. \'olutidae in Japan. Illustrated Catalogue of Japanese Shells l(5):31-38, pis. 5-7. Kuroda, T, T. Habe, and K. Oyama. 1971. The sea shells of Sagami Bay. Maruzen Co., Ltd., 489 p., 121 pis., 51 p. index. Lamarck, J. B. P. A. 1799. Prodrome dune nouvelle classi- fication des coquilles. Memoires de la Societe d'Histoire Naturelle de Paris 1:63-91. Locard, A. 1897. Mollusques Testaces, I. E.xpeditions scien- tifiques du Travailleur et du Talisman. Masson, Paris, 516 p. MacNeil, F. S. 1960. Tertiary and Quaternary Gastropoda of Okinawa. Geological Survey Professional Paper 339. 148 p.. 19 pis. von Martens, E. 1897. Conchologische Miscellen II. .\rchiv fur Naturgeschichte 63(1): 157- 180, pis. 15-17 Meek, F. B. 1876. A report on the invertebrate Cretaceous and Tertiary fossils of the L pper Missouri Country L' S. Geological Survey of the Territories Report 9:l\iv + 629 p. Moses, S. T. 1923. The anatomy of the chank (Turbinella pyrum). Madras Fisheries Bulletin 17:105-127. Nelson, C. M. 1978. Neptunea (Gastropoda: Buccinacea) in the Neogene of the North Pacific and adjacent Bering Sea. The Veliger 21(2):203-215. Norman, A. M. 1879. The Mollusca of the fjords near Bergen. Journal of Conchology 2:8-77. Ponder, \V. F. 1973. The origin and evolution of the Neo- gastropoda. Malacologia 12(21:295-338. Quinn,J. F. 1981. .A new genus of Turbniellidae (Gastropoda: Prosobranchia), with the description of a new species from the Caribbean Sea. The Nautilus 95(2):72-77. Rehder, H. A. 1967. A new genus and two new species in the families Volutidae and Turbinellidae (Mollusca: Gas- tropoda) from the western Pacific. Pacific Science 21(2): 182-187. Sakurai, K. 1957. On a new species of Xancidae, Ccrato- xancus elongatus (Gastropoda). Venus 19:161-163, Shikama, T, 1963. Selected shells of the world illustrated in colours. Hokurvu-Kan Publishing Co., Ltd., Tokvo, 154 p., 102 pis. Shikama, T. 1971. On some noteworthy marine Gastropoda from southwestern Japan (3). Science Reports Yokahama National University (2)18:27-35, pi. 3. Smith, A. G. and M. Gordon, Jr. 1948, The marine mollusks and brachiopods of Monterev Bav , California and vicinity. Proceedings of the California .•\cademy of Sciences, fourth series 26(8): 147-245. Sohl, N. F. 1963. New gastropod genera from the late L'pper Cretaceous of the east Gulf Coastal Plain. Journal of Pa- leontology 37(4):747-757, pis. 89, 90. Sohl, N. F. 1964. Neogastropoda, Opisthobranchia and Ba- sommatophora from the Ripley, Owl Creek, and Prairie Bluff formations. U.S. Geological Survey Professional Pa- per 331-B: 153-344, pis. 19-52. Stanton, T. W. 1920. The fauna of the Cannonball marine member of the Lance Formation. U.S. Geological Survev Professional Paper 128-A, 49 p., 9 pis. Stimpson, W. 1865. On certain genera and families of zoo- phagous gastropods. American Journal of Conchology 1: 55-64. Stoliczka, F. 1868. Cretaceous fauna of southern India. Gas- tropoda of the Cretaceous rocks of southern India. Memoirs of the Geological Survev- of India, Paleontologia Indica, \ol. 2, Ser. 5, pts. 1-10, 497 p., 28 pis. Swofford, D. L. 1985. PAUP, phvlogenetic analysis using parsimonv. Illinois Natural History Survey, Cham- paign, IL. Taki, I. and K. Oyama. 1954. Matajiro Yokoyama's, The Pliocene and later faunas from the Kwanto region in Japan. Paleontological Society of Japan, Special Paper 2, 68 p., 49 pis. Taylor, J. D., N. J. Morris, and C. N. Taylor. 1980. Food specialization and the evolution of predatory prosobranch gastropods. Paleontologv 23(2):375-409. Thiele, J. 1929 Handbuch der systematischen Weichtier- kunde, 1. G. Fischer, Jena, 376 p. Vokes, E. H. 1964. The genus Turbinella (Mollusca, Gastrop- oda) in the New World. Tulane Studies in Geology 2(2): 39-68. Wenz, W. 1938-43. Teil 6. Prosobranchia. In: Schindewolf, O. H. (ed). Handbuch der Palaozoologie. Borntraeger, Berlin, vi -I- 1639 p Wilkinson, L. 1986, SYSTAT: the sv stem for statistics, Systat, Inc., Evanston, IL. Yokoyama, M. 1920. Fossils from the Miura Peninsula and its immediate north. Tokyo Imperial University, College of Science Journal 39(6):l'-193, pis. 1-19. THE NAUTILUS 101(4):182-185, 1987 Page 182 The Freshwater Mussels (Unionidae) of the Upper Ohio River, Greenup and Belleville Pools, West Virginia Michael A. Zeto West Virginia Department of Natural Resources Division of Water Resources General Delivery McArtfiur, WV 25873, USA ^ illiani A. Tolin United States Fish and Wildlife Service P.O. Box 1278 Elkins, WV 26241, USA John E. Schmidt West Virginia Department of Natural Resources 1800 Washington Street East Charleston, WV 2.5305, USA ABSTRACT .•\ preliminary survey of freshwater mussels inhabiting areas around the Ohio River islands of West Virginia was conducted in 1983 b\ the U.S. Fish and Wildlife Service, assisted by the West \'irginia Department of Natural Resources. This survey concluded that the Greenup and Belleville pools displayed a far greater abundance and diversity of mussels than the re- maining navigational pools along West Virginia, and warranted further investigation. During the spring and summer months of 1985, numerous collections were made at various points %\ ithin the two navigational pools to expand the data previously collected Twentv -four species of unionid mussels and Corbic- ula were collected from these areas, representing 16 and 23 species from the Greenup and Belleville pools, respectiveK , No species on the federal endangered species list were encountered, however four of the species collected are considered endan- gered by the State of Ohio, INTRODUCTION A very limited amount of freshwater mussel research has been performed on the mainstem Ohio River within West Virginia. The only recent studies were those con- ducted by Taylor (1980) and the U.S. Fish and Wildlife Service (1983) for the U.S. Army Corps of Engineers, Huntington District. Several of the major tributaries of the Ohio River have been surveyed by the West Virginia Department of Natural Resources, Division of Water Resources, in conjunction with a statewide inventory of mussel populations. These surveys include those by Zeto (1982) on the Monongahela River Basin, Schmidt et al. (1983) on the Little Kanawha River Basin, and Schmidt and Zeto (1983) on the Kanawfia River. Other recent studies on these major Ohio River tributaries are those by Taylor (1983), Clarke (1982), and Morris and Taylor (1978), all on the Kanawha River, .\ re\ie\\ of literature records of the Nhiskinginn River, Ohio has recently been prepared by Stansbery et al. (1985) for the U.S. Arnn Corps of Engineers, Huntington District It became evident from Taylor's 1980 Ohio Hi\er sur- vey that a viable nnissel population did exist in the river. This work, however, was based mainK on the collection of shell material and did not actually locate li\e mussel beds. The work performed by the L'.S. Fish and VN'ildlife Service in 1983 indicated the presence of several exten- sive mussel beds closely associated with the Ohio River islands. The present sur\e\ represents a joint effort by the U.S. Fish and Wildlife Service and the West \'irginia Department of Natural Resources, Division of Water Resources. The information presented was collected in 1983 and 1985 from locations in the Greenup and Belle- ville pools of the Ohio River. These data indicate that several of the mussel species presumed extirpated from the river are still present in isolated areas. STUDY AREA The Ohio River adjacent to West Virginia extends from the Ohio- West Virginia-Pennsylvania state line (RM 40. 1 ) to the common corner of Ohio-Kentuck\-West X'irginia (RM 317.1), forming the state's western boundary with Ohio. The 277 miles of the river along West N'irginia are composed of eight navigational pools, including the Greenup and Belleville pools (figure 1). The Greenup pool is formed at Greenup lock and dam at RM 341.0 near Greenup, Kentucky, and extends up- river into West Virginia. The pool is 61.8 miles long and terminates at RM 279.2 at the Gallipolis lock and dam. Numerous locations were sur\e>ed in the Greenup pool for freshwater mussels during the survey, including the two sites reported here that were found to support sig- nificant populations of mussels Site 1 is located at RM 292.4 along the right descending bank near Green Bot- tom, Cabell County, W^est Virginia (38°34'25"N, 82°17'34"W). The substrate consists of sand, gravel, cob- ble, and boulders. Site 2 is located at the head of Lesage Island (RM 289) near the common boundar\ of Mason antl Cabell counties. West \irginia and Gallia C^ount), Ohio (38°1 4' I7"N, 82°14'54"W). Substrate at this location consists primarily of sand, gravel, and cobble. The Belleville pool originates at Belleville lock and dam at RM 203,9 at Bellrx illc. Wood Counts , West \'ir- M. A. Zeto ei ai, 1987 Page 183 giiiia. The pool terminates upri\er at tlie Willow Island lock and dam, and has a total length of 42,1 miles. Five sites were chosen from those sur\eyed for inclusion in this report. Site 3 is located farthest down-river of the Belle\ille pool sites. It is situated at the head and back channel of Neal Island near Parkersburg, Wood Count\ , West Virginia at RM 181.1 to RM IH2 (39°18'37"N, 81°33'24"W). Substrate varies from sand, gravel, and cobble at the island head to a combination of silt, sand, and gravel in the back channel. Site 4 is situated below the toe of Vienna (Halfway) Island near Vienna, Wood County, West Virginia (39°20'22"N, Sr33'26"W). The mussel bed extends from RM 179 to RM 179.9, and has a substrate consisting of sand, gravel, and cobble. Site 5 is located at the head of Vienna (Halfwa\) Island, ex- tending into the back channel of the island. This site is also located near Vienna, Wood County, West Virginia at RM 178.1 (39°21'24"N, 81°32'28"W).' The substrate is mainly composed of silt, sand, and gravel. Site 6 extends from above the head of Muskingum Island (RM 175.2) through its back channel and onto the toe of the island (RM 177.4), where the bed is situated near the navigation channel. Muskingum Island lies approximately 3 miles northeast of Vienna, Wood Countw West Virginia (39°22'00"N, 81°32'19"W), This island back channel has substrate consisting primariK- of silt, sand, and gravel. Site 7 lies entirely in the back channel of Marietta (Buck- ley) Island at RM 169.1 near Williamstown, Wood Coun- ty, West Virginia (39°23'14"N, 81°24'43"W). The sub- strate at this site is composed of silt, sand, and gravel. Sampling sites are depicted in figure 1. METHODS Sampling sites were chosen by one of two methods. The first method involved "follow-up' surveys of areas sur- Little Hocking River Shade River GREENUP Figure 1. Ohio River, West Virginia Sampling sites are in- dicated. Specific locations are identified in text. rounding the Ohio River islands. The initial stud\ of these island areas was conducted b\ the US, Fish and Wildlife Service (1983), and indicated that several of these island areas in the Greenup and Belleville pools had a very rich mussel fauna. The second method of site selection was simply choosing areas in the river associated Table 1. Freshwater mussels of the Ohio River, Greenup pool. West \'irginia. Species Site number Totiil iiiinihfr Percent relative 1 ."> collected abundance 1' 1 0,26 2 2 0,53 14 87 101 26,65 10 28 38 10,03 1,3 20 33 8,71 3 10 13 3,43 1 1 0.26 7 7 1.85 14 2 16 4,22 103 8 111 29,29 1 8 9 2,37 9 9 2,37 2 2 0,53 1 2 3 0,79 0 1 3 0.79 26 4 30 7.92 11 15 379 100 00 Sirophitus undulatus tindulatus (Say, 1817) Lasmigona complanata (Barnes, 1823) Qtiadnila qiiadrula (Rafinesque, 1820) Qtiadnda mctanevra (Rafinesque, 1820) Quadnda pustidosa pustulosa (Lea, 1831) Amblema plicata plicata (Say, 1817) Fusconaia flava (Rafinesque, 1820) Plethobasus cyphijus (Rafinesque, 1820) Pleurobema cordatum (Rafinesque, 1820) Elliptio crassidens crassidens (Lamarck, 1819) Obliqiiaha reflcxa (Rafinesque, 1820) Ac?i;io;iflia,s bgomentina carinata (Barnes, 1823) Leptodea jragilis (Rafinesque, 1820) Potamihis alatus (Say, 1817) Ligumia recta (Lamarck, 1819) Lampsdis ventricosa (Barnes, 1823) Total NOTE: Carbuida sp was also found at each sampling location ' Fresh dead shell Page 184 THE NAUTILUS, Vol. 101, No. 4 Table 2. Freshwater mussels ol the Ohio Hl\cr, Belleville pool. West Virginia. Species Site lumiber Total number Percent relative 3 4 .5 6 1 collected abundance Anodunta imhccillis (Sa\. 1S29) Anodonta grandis gmndis (Say, 1829) Strophittis undulatus undulatus (Say, 1817) Lasmigona complanata (Barnes, 1823) Magnonaias nervosa (Rafinesque, 1820) (^huulrula quadrula (Rafinesque, 1820) (Juadndn ntctancvra (Rafinesque, 1820) (^)ii(idnil(i piislulosa piistulosa (Lea, 1831) Andilcnia plicala pHcala (Sa\, 1817) Fusconaia flava (Rafinesque, 1820) PIcthobasus ctjphyus (Rafinesque, 1820) Pleurobema curdatum (Rafinesque, 1820) Elliptio crassidens crassidens (Lamarck, 1819) Uniomerus tetralasnms (Say, 1831) Ohliquaria reflexa (Rafinesque, 1820) Actinonaias ligamentina carinata (Barnes, 1823) Obovaria subroiiinda (Rafinesciue, 1820) Tntncilla donaciformis (Lea, 1827) Lcptodca fragili.s (Rafinesque, 1820) Potaniilus alatus (Sa>, 1817) Potamdus ohiensis (Rafinesque, 1820) Lampsdis radiata luteola (Lamarck, 1819) Lampsilis ventricosa (Barnes, 1823) Total 1 4 1 67 339 1 12 1 14 8 82 5' 1 3 1 3 3 3 1 1 13 15 2 7 1 5 1' 1 17 V 1 1 3 4 89 273 6 2 24 10 49 5 4 1 3 2 I 4 1' 3 18 6 11 2 2 9 4 768 19 47 160 10 1 4 1 1 21 1 5 15 7 15 2 1 5 1103 0.27 0.18 0.18 0.82 0.36 69.63 1.72 4.26 14 51 0.91 0.09 0.36 0,09 0.09 1.90 0.09 0.45 1.36 0.64 1.36 0.18 0.09 0.45 99.99 NOTE: C.oriiicida sp, ' Fresh dead sliell llso fouinl at each saniplnig location. with the force of the thalweg, mainly river bends. River bends are generally "clean-swept" by the river's current and are likely areas for mussels to populate, especially near the outside of the turn. The primary method of sampling was by brailing, utilizing both dovetail and crowfoot brail hooks. Shallow water and the shoreline were also surveyed for fresh- dead shells and midden piles. How ever, at the sites sur- veyed the vast majority of the mussel beds were located in 12-18 feet of water. As material was collected in the field, a preliminary species list was compiled on site. A suitable number of individuals were retained for positive identification and as voucher specimens. These have been accessioned in the Ohio State University Museum of Zo- ology. Dr. David Stansbery aided in the identification of the specimens. RESULTS \ total of 24 species of freshwater iniioTiid mussels as well as the Asiatic clam Corhictila were collected from the areas surveyed. The Greenup pool (table 1 ) supported 16 species of mussels, with the dominant species Elliptio crassidens crassidens and Quadrula quadrula having re- spective relative abundances of 29.29 and 2(i.6.5''7 of the population sampled. A significant portion ol the mussel fauna in this pool was also comprised of Quadrula rne- lanevra and Quadrula pustulosa pustulosa, representing 10.03 and 8.71'^c of the sample, respectiveK. The pop- ulation of Site 1 was dominated by £. c. crassidens, while Q. quadrula was dominant at Site 2. The occurrence of £. c. crassidens at Site 1 represented the most significant population of this species, once thought to be extirpated from the upper Ohio River, in this portion of the river. The Belleville pool was apparently more diverse in species composition than the Greenup pool, supporting 23 species of imionid mussels, in addition to Corbicula (table 2). By far the dominant species in the Belleville pool was Q. quadrula. which had a relative abundance of nearly 70%, followed b\ Amblema plicala plicata, comprising 14.51/t of the population. This situation also held true for individual site analyses of areas 3, 4, 5, and (i At Site 7, however, a drastic decrease of species di- versity and total population w as apparent, as only four species were collected at this site. Investigation of nu- merous sites in the remaining 7 miles (RM 162-169) of the Belle\ ille pool above Site 7 indicated that this region of the Ohio River was nearly devoid of unionids. Only a few (< 10) specimens of Q. quadrula and A. p. plicata were taken in this upper 7 mile reach of the Belleville pool. DISCUSSION The authors believe the greater species diversil\ in the Belleville pool is influenced by several factors. Several M. A. Zeto ('( al.. 1987 Page 185 major rivers (Muskingum aiul Little Kanawha) enter tlie Ohio River in tlie Belleville pool close to the study areas. These rivers contain significant mussel populations (Schmidt et al, 1983; Stansbery et al., 1985) which un- doubtedK- have contributed to the Ohio Ri\er fauna. The Belle\ ille pool also contains numerous islands w ithin its boundaries. The back channels of these islands not only provide a refuge from naxigational and dredging im- pacts, but also provide a variet\ of habitats for mussel populations. In comparison, the tributaries of the Green- up pool are believed to ha\e little influence on the Ohio River mussel populations, and there is also far less island habitat in this pool. In comparing the relative abundances of the mussel populations in the two pools sur\e\ed, it is very apparent that the Greenup pool has a more evenK dispersed faunal representation than the Belleville pool. This may be at- tributed to the smaller amount of industrialization and somewhat isolated condition existing in the stud\ area of the Greenup pool, resulting in fewer negative impacts to the river. Several species collected during this survev' had been presumed extirpated from the Ohio Ri\er in West \'ir- ginia (Ta\lor. 1980). These species are: Elliptio cmssi- dcns crassidens, Actinonaias ligamentina carinata, Plethobasis cyphyus. Ligumia recta, Truncilla donaci- formis (later reported present by Taylor, The Ohio River Biology Symposium, Huntington, WV, 1984). Four of the species collected, Quadrula metanevra. Plethobasis cyphyus, Pleurobema cordatum, and Potamitus ohien- sis, are considered endangered by the State of Ohio (Stansbery, 1976). No species listed as endangered by the federal government were encountered. ACKNOWLEDGEMENTS The authors extend their sincere appreciation to Dr. Da- vid Stansbery for assistance with identification and for his interest in this project. LITERATURE CITED Clarke, \. H. 1982. Surve\ of the freshwater mussels of (he Upper Kanawha River (RM 91-95), Fayette County, West Virginia, with special reference to Epioblasma torulosa torulosa and Lampsilis abrupta. U.S. Fish and WildHfe Service, Newton Corner, M.\, 104 p. Morris, J. S. and R. W. Taylor. 1978. A survey of the fresh- water mussels of the Kanawha River of West Virginia The Nautilus 92(4);153-155. Schmidt, J. E. and M. A. Zeto. 1983. A surve\ of the fresh- water mussel fauna of the Kanawha River September 1981- September 1982. Proceedings of the West Virginia .Acad- emy of Sciences 55(2-4):72-75. Schmidt, J. E., M. A. Zeto, and R. W. Taylor. 1983. A survey of the mussel fauna of the Little Kanawha River Basin, Report of Freshwater Mussels Workshop, 26-27 October 1982. U.S. .Army Engineers Waterways Experiment Sta- tion, Vicksburg, MS, 196 p. Stansber), D, H, 1976. Ohio's endangered naiad mollusks. ,\nnual Meeting of the .American Malacological Inion Stansber) , D. H., K. E. Newman, K. G. Borror, and C. B. Stein 1985. Literature records of bivalve mollusks of the Mus- kingum River system, Ohio. U.S. .Army Corps of Engi- neers, Huntington District, 472 p Ta\lor, R. W. 1980. A survey of the freshwater mussels of the Ohio Ri\er from Greenup locks and dam to Pittsburgh, Pennsylvania. U.S. .Arm>' Corps of Engineers, Huntington/ Pittsburgh Districts, 71 p. Taylor, R. W. 1983. A survey of the freshwater mussels of the Kanawha River. U.S. Army Corps of Engineers, Hun- tington District, 62 p. U.S. Fish and Wildlife Service, Department of the Interior. W. .A. Tolin and P. .A. Schettig (principal investigators). 1983. .A ph\ sical and biological survey of the Ohio River islands (Huntington District). 315 p. Zeto, M. A. 1982. Noteson the freshwater mussels (Unionidae) of the Upper Monongahela River Basin, West Virginia. The Nautilus 96(4): 127-129. THE NAUTILUS I01(4):186-187, 1987 Page 186 New Distributional Records for Polygyriscus virginianus (Burch, 1947) (Pulmonata: Helicodiscidae) Robert E. Balie Department of Biology Radford University Radford, VA 24142, USA INTRODUCTION Because of its secretive habits, few specimens of the Virginia fringed mountain snail have ever been seen. Solem (1976) regarded this species as one of the rarest snails in North America and in 1978 it was placed on the Federal Endangered Species List (U.S. Government Document, 1978). Of the 146 documented specimens collected since 1937, only 27 were live collected. In 1948 Burch found two living adults (Hubricht, personal com- munication), Hubricht (1972) found 21 (14 adults, seven juveniles) in 1971 and Grimm (1981) found three adults. All of these were collected from a single talus rock pile (type locality) at the base of high limestone (Elbrook formation) bluffs along the New River in Pulaski County, Virginia. Except for a single shell found 6.6 km southwest of the t\ pe locality in 1937, all specimens collected prior to 1981 were found in or near this 9 square meter rock pile. Grimm (1981) expanded the range of this snail to include four additional sites within 1 km of the type locality. All 26 living specimens collected through 1981, however, were confined to the t) pe locality , and all spec- imens were found 25 cm or deeper in the substrate. This report documents the collection of the 27th living spec- imen, and includes a range extension represented by four additional shells (voucher specimens USNM 859139, USNM 859140, and USNM 859141). To date, Polygyriscus virginianus has been found as- sociated only with weathered Elbrook formation (Cam- brian) dolomitic limestone along the New River bluffs in Pulaski Count}-, Virginia. This secretive species has been described as a burrowing calciphile (Hui:)richt, 1985). and has been found burrowing at 10 cm to 60 cm depths in fragmented limestone mixed with rootlets and a clayey soil (Grimm, 1981; Batie, 1986), It is associated with permanently damp soil under limestone talus at the base of high bluffs. The talus slopes are usually heavily shaded, vine-covered, and with little accumulated humus or or- ganic matter. METHODS An area within a 16.1 km (10 mile) radius around the known habitat was searched for over 300 hr during a year-long effort (July, 1985-.\ugust, 1986) to establish the actual distribution of this species. Soil samples from nearK 200 holes, each measuring 25 cm across and 45- 60 cm deep, were collected v\ith a garden trowel and sifted using a 2.0 mm screen in tandem with a 0.5 mm screen. Snails were hand picked from the screens and examined in the held with a 7-10 x hand lens. RESULTS During the study, 30 adult specimens were collected. Of these, 25 emptv shells and one living snail were collected within about 1.1 km of the type locality. Four additional shells were collected at sites up to 3.3 km northeast of the tvpe localit\ , This range extension gives a total doc- umented range of only 9.9 km for shells of this species. Although no li\ ing snails were found at the new northeast sites, a single living snail was observed and released 70 m southwest of the type locality at 10 cm depth. Living snails have now been documented onl\ along a 70 m stretch of the river bluffs. Although previous studies (Burch, 1947; Grimm, 1981; Hubricht, 1985) indicated that this species was found only at depths exceeding 25 cm, with most being found at the 45 cm level, Solem (1976) indicated that Poly- gyriscus may move to the surface during wet weather. Finding this single live specimen at the 10 cm level on moist rock fragments strengthens Solem's argument. It thus seems that Polygyriscus can exist in a somewhat broader vertical zone than was pre\iousl\ reported No surface activit\, however, was noted during nearly 14 hr of rainy, nighttime collecting. LITERATURE CITED Batie, R. E, 1986. Distribution and abundance of Polygyriscus virginianus (Burch, 1947), the X'irginia fringed mountain snail. Contract Report to the N'irginia Commission of Game and Inland Fisheries, Richmond, \'.\, 27 p. Burch, P. R. 1947. Polygyra virginiana, a new species from Virginia. The Nautilus 6U2):40-41. Grinun, F. W, 1981. Distribution, habitat requirements and recovery needs of the endangered land snail, Polygyriscus R. E. Batie, 1987 Page 187 virginianus. Contract Report to the L'S, Fish and WildHfe Service. Washington, DC, 17 p. Hubricht, L 1972 Two new North American Puhnonata: Paravitrea seradens and Philuinticu'i scllatiis. The Nau- tilus 86(1):16-17. Hubricht, L, 1985. The distribution of the nati\e land mol- lusks of the eastern Linited States. F"ieldiana; Zoology, new series 24:1-191. Soleni, A. 197(1 Endangered status of eastern I nited States land snails. Contract Report to the U.S. Fish and Wildlife Service, Washington, DC. OES Contract Number 14-16- 0008-764, 9 p. U.S. Government Document. 1978. Determmation that seven eastern U.S. land snails are endangered or threatened species. Federal Register 43(128), July 3:28932-28935. THE NAUTILUS 101(4):188-193, 1987 Page 188 Sympatric Occurrence of Living Nautilus (N. pompilius and N. stenomphalus) on the Great Barrier Reef, Australia ^ . B. Saunders Department of Geology Brvn Mawr College Brvn Mawr, PA 19010, USA P. D. Ward Department of Geology University of Washington Seattle, WA 98195, USA ABSTRACT Two species of Nautilus. S. pompilius Linnaeus, 1758 and N. stenomphalus Sowerb\ , 1849, inhabit the deep forereef slopes off Lizard Island, on the Great Barrier Reef^ Of 29 specimens trapped at 250-440 m depth, 11 are typical of the widespread species N. pompilius, seven others show shell characteristics of N. stenomphalus. and exhibit a unique, strongly nodose hood texture; 1 1 specimens show features that are intermediate be- tween these two species. The Lizard Island record represents the first known locale where living specimens ol N. stenom- phalus have been found, the second example of sympatric species of Nautilus, and it may be the first known example of hybridization between two species of Nautilus. INTRODUCTION The presence of living Nautilus on Australia's Great Bar- rier Reef has long been suspected on the basis of the fairly common presence of drifted shells. Iredaie (1944) even erected a species for the North Queensland drift shells (N. alumnus Iredaie, 1944). Another species (N. stenomphalus Sowerby, 1849) was thought to occur there as well. A third species, N. repertus Iredaie, 1944, was named iot drift shells thought to originate from southern and western Australian waters. Nevertheless, the only published accounts of Australian Nautilus consist of de- scriptions of isolated drift shells (Iredaie, 1944; Cotton, 1957) and a few reports of beach-stranded or trawled specimens (e.g.. Riddle, 1920); no systematic description or analysis of any of this material has previously been undertaken. The present account is a report on the successful results of deep-water trapping lor Nautilus, iluring June and December, 1985, off Lizard Island, Queensland (figure 1). Twenty-nine specimens were obtained, that appear to include two distinct species: Nautilus pompilius Lin- naeus, 1758 and N. stenomphalus Sowerby, 1849. The Great Barrier Reef occurrence ol Nautilus is important in that it includes the first living specimens referable to N. stenomphalus, and it is onl\ the second known oc- currence of sympatric species of Nautilus (Saunders et al., 1987). Following is a brief description of the specimens; 18 conform to the definitions of either A', pompilius or as iV. stenomphalus. The remainder exhibit characteristics that are to varying degrees intermediate between the two species, and they are accordingly identified as N. pompilius? or as N. stenomphalus'' (figure 2). These intermediate forms appear to represent In bridization between sympatric species of Nautilus. MATERIALS AND METHODS Grouper- and mackrel-baited, baffle-style traps, measur- ing ca. 1 m X 1 m x 2 m were set at depths of 140 m to approximately 440 m, off Carter Reef, just north ol Cook's Passage, approximately 20 km northeast of Lizard Island, Queensland (figure 1). Traps were buoyed at the surface, anil, v\hen po.ssible, were retrie\ed after one to three nights. Overall, the trap \ields were sparse com- pared to those obtained at other Nautilus trapping sites; the highest yield was five animals, in an overnight trap at 400-440 m depth. By comparison, as many as 34 and 67 Nautilus per trap were obtained in Papua New Guinea and in Palau, respectively (Saunders & Ward, 1987; Saunders et al., 1987). On the Great Barrier Reef, how- ever, high surface currents combined with steep bottom slopes caused extensi\e trap drifting, making an\ con- clusions regarding depth tlistribution or relative abun- dance of Nautilus in this area tentati\e. Following re- trieval, animals were measured, weighed, sexed, photographed, and tissue .samples were taken for elec- trojjhoretic anaK sis. Reference specimens ha\ e been re- posited v\ith the Australian Museum, Sydney (AM C^ 148211, 148212, 148214-148216), the American Mu- seum of Natural History, New York (Lz 24), and at the National Museum of Natural History, Washington, D.C. (USNM 816710-816713). W. B. Saunders and P. D. Ward, 1987 Page 189 LIZARD ISLAND Figure 1. Location map shov\iiig deep-water trapsite off Car- ter Beef. Great Barrier Reet, Queensland, w here Satitilus pom- pilius and N. stenomphahis were obtained at 2.50-440 m depth, DESCRIPTION Nautilus pompilius Linnaeus, 1758 T\'picall\', the shell of N. pompilius is ca. 165 mm di- ameter and has a small umbilicus that is filled with a callus, with but rare exceptions (Saunders, 1981, 1987; Saunders ct al.. 19S7). Shell coloration is variable, but characteristicalK exhibits irregularK' bifurcating, radial brow n stripes extending from umbilicus to \enter (figures 7, 12). The reddish-brown hood is covered with low, rounded, white elevations, giving it a mottled, slightly bumpy appearance (figures 7, 8). The 11 specimens of N. pompilius available for stud\' from the Great Barrier Reef difter in no major respect from conspecific specimens from the Philippines. They are slightly smaller, with a mean mature shell diameter of 155.2 mm, and mean weight (bod\' plus shell) of 640.6 g (table 1). The pattern of shell coloration is also similar, with the exception of tw o specimens (Lz 5, 13) that lack color banding in the umbilical region. This same pattern characterizes N. steuomphalus but it also occurs as a rare 1 1 N. pompilius ri 1 j possible hybrids ^^^ N. stenomphalus 1 1 1 1 1 ^ 1 ^^^^— ^ 85 95 105 115 125 135 145 155 165 175 185 Shell diemeter (mm) Figure 2. Frequenc) distribution showing ma.vimum shell di- ameter of 29 li\'e-caught specimens of A', pompilius, S ste- nomphalus. and intermediates or presumed inbrids (A', pom- pilius?. N. stcnoiuphalus?). variation in populations of both N. pompilius and N. belauensis. The color of the banding in most specimens is brick-red, which is typical of the species. One specimen (Lz 13) exhibits yellow-brown stripes; such coloration is thought to characterize the questionable Australian taxon xV. repcrtus (Saunders, 1981. 1987). The color bands of the Lizard Island specimens do not coalesce across the ventral region. In this respect they more closely resemble typical N. pompilius from the Philippines than the geo- graphicall)' closer forms from Papua New Guinea (Saun- ders & Davis, 1985; Saunders ff al.. 1987). Man\- of these generalizations, however, could require amendment as more specimens become available for study. Nautilus stenomphalus Sowerby, 1849 The shell form is similar, if not identical, to N. pompilius, except that the umbilicus is open, lacking a callus, and shell coloration is reduced, lacking stripes in the umbil- ical region (figures 3-5, 9, 11). The surface of the hood exhibits a rough, nodose texture that is produced by a series of highly irregular papillae (figures 3, 5). This texture ma\ extend to some of the tentacular sheaths as well. Seven of the 29 specimens of Nautilus obtained from the Great Barrier Reef are attributable to N. stenom- phalus. heretofore known only from drifted shells. This species is similar in size to N. pompilius (figure 2) with Table 1. Data from mature .V stciu>mphalus and .V. pompilius from Carter Reef, off Lizard Island, Great Barrier Reef. Nautilus stenomphalus Nautilus pompilius Shell diameter (mm) Shell w dth (mm) Total weight ( g' Sex Range Mean SD Range Mean SD Range Mean SD Females n = 2) 141.7-147.8 144,8 4,3 63,3-64,3 63,8 0,5 422-480 451 41 Males (n = 4) 157.9-170.4 163 5,3 74.2-80.3 76.6 2.7 650-730 682.5 39,5 Total (n = 6) 141.7-170,4 156.9 10,5 63.3-80.3 72.3 6.9 422-730 605.3 124,8 Females n = 2) 142.3-154.8 148,6 — 60.3-73 66.7 — — — Males (n = 8) 147.2-165.2 156.9 616 67,2-77,4 73,7 3,5 540-710 641 4 70,9 Total (n = 10) 142,'3-1652 1,55 2 7,1 60,3-77 4 72 3 5 2 540-710 640 6 65 7 Page 190 THE NAUTILUS, Vol. 101, No. 4 Figures 3-8. Photographs ot living \aulilus xtenomphalus (.3, 4, .5. 8) and N. pompilius (6, 7) from Charter Reef, Queenslaiul. 3. iV. stenoniphalus (Lz 7) photographed in .shallow water, showing characteristic open umbilicus, lack of umbilical coloration, and distinctively textured hood (x '2 approx.). 4, 5. N. stenomphalns, closeup views of open umbilicus and distinctive, nodose hood texture (Lz 6, USNM 816711; x 2, x 1). 6, 7. N. pompilius showing typical hood texture (6) and full view of animal in atjuarium (Lz 1; X 1, X ',4). 8. N. stenomphalus?, an intermediate form, exhibiting nodose hood texture of .V stcnomphaliis with shell coloration of ,V. pompilius (x "2). Photograph ( 1 ) by T. Landry, (7, 8) by B. Cloldman W. B. Saunders and P. D. Ward, 1987 Page 191 12 Figures 9-12. Shells of live-caught N. pompilius and N. stenomphahis from Carter Reef, Queensland^ 9, 11. N. stenomphalus (Lz 6, USNM S16711; Lz 25, USNM 816712), 10. xV. stenomphalus?. with umbilical callus (Lz 3, USNM 816713). 12. ;V. pompilius (Lz 2, USNM 816710). A\\ figures x 1/2. a mean shell diameter of 156.9 mm, and a mean weight (body plus shell) of 605.3 g. The nodose hood texture appears to be unique among the species of Nautilus: in ail of the dozen or so populations of A', pompilius e.\- amined to date, as well as in S. macromphalus and N. belauensis. the hood markings and texture are the same — reddish-brown, mottled with low, white bumps (figures 6, 7). Only N. scrohiculatus differs in this regard; its hood is covered with closely spaced, conical ele\ations (Saun- ders e< al, 1987: figs. 7, 8). All seven of the specimens identified as N. stenom- phalus (i.e., those that have an open umbilicus and lack umbilical color bands) show the uniqueK' textured hood, it being more or less equally developed in each. The surface of some of the outer tentacular sheaths, which. like the hood, are composed of non-muscular, cartilagi- nous tissue, also show an irregular, somewhat digitated appearance that has not been previousK- noted among the other described species of Mautikis. DISCUSSION In considering the relationship between N. pompilius and .V. stenomphalus. it is important to note that both species were originally described soleK on the basis of shell characteristics. Sowerby (1849:465, pi. 98, fig. 3) distinguished the latter by its small, open umbilicus, and by the color pattern, in which the stripes do not extend to the umbilicus. The localit\ for Sowerbv s figured spec- imen was not cited. Little else has been known of this Page 192 THE NAUTILUS, Vol. 101, No. 4 Table 2. Tal)ulati()ii ol sex. inatiiiit\ . and spt'cies-distinguishing characteristics in Nautilus ponipiltus and N. slenoinphalus from Carter Reef .Vhbrex iations as follows: Mat, maturity (M, fully mature; MBI, Ijarely mature; I. immature); Sex, male or female; Di.stinguisliiiig characteristics, 1-.3, typical N. pompilius (1, umbilical callus; 2, color bands extend to umbilicus; 3, mottled, low- relief hood texture); 4-6, t\ pical jV, stcnomphalus (-4. open umbilicus, callus lacking; .5, umbilical area lacks color bands; 6, nodose hood texture). Nautilus pompilius possesses characteristics 1-3, N. sti'nomphalus 4-6. Intermediates (possible hybrids) are identified as .V. pompilius? and N. stenomphalus? and lack one or more of the typical species shell characteristics (coloration or umbilical callus), but none identified as N. pompilius exhibits the roughls textured hood of N. stenomphalus. Thus, although there is some overlap in the shell characteristics, the combination of shell and hood characteristics appears to distinguish the two species. Spec. Ill Sc\ Mat Distiiig char I. N. pompilius I Lz 1 (AM C 148212) 2. Lz 2 (USNM 816710) 3. Lz 8 (AM C 148216) 4. Lz9 5. Lz 16 6. Lz 17 7. Lz 19 8. Lz20 9. Lz21 10. Lz22 11 Lz26 II. .V. pompilius? 1. Lz5 2, Lz 13 III. N. slcnomphalus"^ 1. Lz 3 (USNM 816713) 2. Lz 4 (AM C 148215) 3. Lz 12 4. Lz 15 5. Lz 18 6. Lz28 7. Lz29 8. Lz30 9. Lz31 W. iV. stenomphalus 1. Lz6(USNM 816711) 2. Lz7 3. Lz 10 (AM C: 148211) 4. Lz 11 5. Lz23 6. Lz24 7. Lz 25 (USNM 816712) 9 \I 1. 2. 3 6 M 1, 2, 3 S M 1, 2, 3 6 M 1, 2.3 S MBI 1, 2,3 9 M 1, 2, 3 6 M 1, 2, 3 S MBI 1, 2, 3 S M 1, 2, 3 S M 1, 2, 3 6 M 1, 2, 3 ? I 1, 3, 5 9 MBI 1,3, 5 S M 1, 5. 6 S MBI 1, 2, 6 S M 1, 2, 6 6 M 1, 5, 6 6 MBI 1. 5, 6 S I 1, 2, 6 S M 1, 5, 6 S M 1, 5, 6 S M 1, 2,6 S M 4, 5, 6 S MBI 4, 5, 6 S M 4, 5, 6 ? I 4,5, 6 9 MBI 4, 5, 6 9 M 4. 5, 6 S M 4. 5. 6 questionable taxon; in fact, Saunders (1981) suggested that it might be a variant of N. pompilius, in which the callus was lacking, and the coloration reduced, as both features are known to occur separately in most popula- tions of iV. pompilius. But, as the Lizard Island specimens show, N. stemjmphalus al.so has a distinctl) textured hood. Thus, while N. stenomphalus is distinguishable from N. pompilius, it appears that in every case it might not be possible to separate them on the basis of shell characteristics alone; soft part morphology is also re- quired. Of the 1 1 Lizard Island "intermediates' (table 2; figure 2), two are regarded as representing A', pompiliu.'i?, be- cause they show just one shell characteristic of N. ste- nomphalus (e.g., a white umbilical area; table 2). Nine specimens identified as N. stenomphalus? show one or two shell characteristics of N. pompilius (a callus and/ or umbilical color bands), but not the distinctive hood texture, which is here regarded as a characteristic of N. stenomphalus (table 2). The presence of intermediate shell morphologies among the Great Barrier Reef specimens raises the possibility of In bridization between the two sympatric species; this is suggested for several reasons. First, the strongly tex- tured hood of iV. stenon^phalus is trul\- unique; nothing like it has ever been recorded, either among the nu- merous populations of N. pompilius examined, or among the thousands of specimens of the morphologicalK sim- ilar species A', belaucnsis. Second, reduced shell coloration and an open umbi- licus are both features that have been observed in many populations of N. pompilius and in S. belauensis — in most cases tlie\ occur as a relativeK rare \ariation and thev have not been observ ed in the same specimen. How- ever, no variant in these species has ever been observed in which the hood texture even approaches that of N. stenomphalus. Third, the Lizard Island [Kipulation tloes not appear to represent a random mixture of morphologies such as one might exited in a single, highly variable population; W. B, Saunders and P. D. Ward, 1987 Page 193 rather, specimens seem to fall clearh into one distinctive category or the other, and the intermediates tend to show stronger affinities with either one or the other. An alternative explanation for the intermediate mor- phologies is that the range of variabilit> of A', pompilius is dramaticalK greater in the Queensland population than in any other documented occurrence of this wide- spread and well known species — enough so that it spans the accepted definition of two separate species. We do not favor this explanation, because (a) there has been no indication of such extremes in variation among the dozen or so populations of N. poinpilius examined to date; and (b) not a single specimen of N. pompilius is known that exhibits the unique hood characteristics of the Lizard Island forms assigned to N. stenomphalus. The Great Barrier Reef is only the second known site where more than a single species of Nautilus occurs sympatricalK (see Saunders rf al.. 1987). In addition, the occasional finds of drifted shells of the questionable species N. repertus Iredale, 1944 in this region (N. McKay, per- sonal communication, 1985) suggest that three distinct species ma\ inhabit the Great Barrier Reef, making this province the most speciose area known for \autilus. It is of interest to consider possible affiliations between the Nautilus found at Lizard Island and those from else- where in the region. The Great Barrier Reef Province is separated from the Papua New Guinea region b\ the narrow, shallow, Torres Straits. Because of the known distribution and locomotory habits of Nautilus (moving along the bottom, with ma.ximum depths of approxi- mateK 600 m), the separation of Australia and Papua New Guinea b\ the Torres Straits would seemingK im- pose only an incomplete barrier to Nautilus migration between these two land areas. However, it would have been a formidable obstacle to migration from the west, particularly during the Pleistocene Epoch, when seale\el was as much as 120 m lower, as recently as 15,000 \ears ago. Although the specimens of N. pompilius found at Liz- ard Island can, to some e.xtent, be distinguished from representatives of this species captured at Port Moresby on the basis of coloration (Saunders & Davis, 1985; Swan & Saunders, 1987), the mature shells are the same size. In turn, the shells from these populations exhibit differ- ences compared to larger morphs of N. pompilius found along the northern island groups of Papua New Guinea, such as Manus and New Ireland (Swan & Saunders, 1987). We suspect that the populations of N. pompilius occur- ring at Lizard Island and off southern Papua New Guinea are, or recentK ha\e been, part of a single, freel\- inter- breeding population. Because of the prevailing north-to- south currents, however, gene flow and migration may be unidirectional from Papua New Guinea to the Great Barrier Reef. The absence of N. stenomphalus and N. repertus drift shells in southern Papua New Guinea may reflect this unidirectional dispersal, and suggest that the two latter forms are endemic to the Great Barrier Reef. The possible hybridization of N. pompilius with N. ste- nomphalus would suggest, according to this scenario, that N. pompilius and N. stenomphalus are sibling species, and that their recent sympatry is the result of N. pom- pilius expanding into the Great Barrier Reef Province. ACKNOWLEDGEMENTS The effort to stud\ Nautilus on the Great Barrier Reef was undertaken w ith the approxal of the Great Barrier Reef Marine Park Authority, and we thank R. A. Ken- chington, D. W. Kinsey, and Wendy Craik for supporting the program. The project was based at the Lizard Island Research Station, where Dr. Barry Goldman, Director, provided insaluable advice and assistance. In addition, we are indebted to Lois Goldman, and to Gwen and Peter Pini, also of the Lizard Island Research Station, and Tom Landry, Seattle, Washington for their assis- tance. Bruce Carlson, Waikiki .\quarium, assisted in de- veloping the effort to trap at Lizard Island. Mrs. N. McKay, of Cairns, Queensland, kindly made available for stud\- drift shells of Nautilus, some of which matched Iredale s (1944) description of iV. repertus. Supported b> a U.S. National Science Foundation Grant (EAR 83-18932) and by the National Geographic Society. LITERATURE CITED Cotton, B. C. 1957. Records of uncommon southern .Austra- lian molluscs. Records South Australian Museum 13:117- 130. Iredale, T. 1944, Australian pearh nautilus. Australian Zo- ologist 10:294-298, Riddle, \. R, 1920, An adventitious occurrence of Nautilus ponipilius. Linne. with a short bibliograph) on ocean cur- rents affecting the .Australian coast. Transactions Ro>al Society South .Australia 4-1:257-262, Saunders, W, B. 1981, The species of living Nautilus and their distribution. The V'eliger 24:8-17. Saunders, W. B. 1987. The species of Nautilus. In: Saunders, W B. and N, H. Landman (eds.). Nautilus: the biology and paleobiology of a living fossil. Plenum Press, New York and London, p. 35-52. Saunders, W. B. and L, E, Davis. 1985. A preliminar\' report on Nautilus in Papua New Guinea. Science in New Guinea 11:60-69, Saunders, W, B,, L, E, Davis, and R, L. Knight. 1987, Sym- patric species of Nautilus (N. pompilius and A', scrohicu- latus) in the .Admiralt\ Islands, Papua New Guinea. The Nautilus 101:93-99, Saunders, VV, B, and P, D, Ward. 1987. Ecology, distribution, and population characteristics of Nautilus. In: Saunders, W. B, and N. H, Landman (eds.). Nautilus: the biology and paleobiology of a living fossil. Plenum Press, New York and London, p, 137-162, Sowerb\, G, B. 1849. Monograph on the genus Nautilus. Thesaurus Conchyliorum 2:463-465. Swan, A. R. H. and W. B, Saunders. 1987. Morphologic \ari- ation in Nautilus from Papua New Guinea, In: Saunders, W. B. and N. H. Landman (eds.). Nautilus: the biology and paleobiology of a living fossil. Plenum Press, New York and London, p. 85-103. THE NAUTILUS 101(4):194-199, 1987 Page 194 On the Availability of Names Proposed in Pacific Shell News, Tokvo, 1970-72 ^ illiani K. Emerson Waller E. Sage, III Department of Invertebrates American Museum of Natural History New York, NY 10024. USA ABSTRACT The nomenclaturai status of two genus-group names and 19 species-group names described in Pacific Shell News. Numbers 1-3 (19701 and 5, 6 (1972) are criticalK re\iewed. The following taxa are available names under provisions of the International Code of Zoological Nomenclature. SPECIES-GROUP NAMES: In Number 1 (January 20, 1970): Conus memiae Habe and Kosuge; Claviscala midwayensis Habe and Kosuge. In Number 2 (April 30, 1970): Cypraea (Erosaria) miijokoae Habe and Kosuge; Clavus regius Habe and Murakami; Fulgoraria glabra Habe and Kosuge; Ctenocardia kinai Habe and Murakami; Conus kintoki Habe and Kosuge. In Number 3 (October 30, 1970): Phyllocoma neglecta Habe and Kosuge; Typhis ramosus Habe and Kosuge; Ginebis corolla Habe and Kosuge; Conus spirofilis Habe and Kosuge. In Number 5 (September 5, 1972): Cornutoconus lamellatus Suzuki; Homalopoma striatum Su- zuki. In Number 6 (December 1, 1972): Latiaxis (sensu stricto) longispinosus Suzuki; Latiaxis (Babelomurex) pagodus perver- nicosus Suzuki. GENUS-GROUP NAME: In Number 5 (Sep- tember 5. 1972): Cornutocoiius Suzuki INTRODUCTION Pacific Shell News (1970 and 1972) was intended as a popular magazine to promote the hobby of shell col- lecting to the Japanese audience. The first three numbers (1970), under the co-editorship of Drs. Tadashige Habe and Sadao Kosuge, are well illustrated with numerous monochrome and a few polychrome photographs. The text, including the illustrations, consists ot about 40 pages per issue; it is mostly in Japanese, but has brief passages in English for some of the species discussed. One of the features of each issue was to provide a notice of forth- coming descriptions of new generic and specific taxa which were to be published in Venm (Japanese Journal of Malacology) or The Nautilus. Not all of the intended descriptions of new taxa by these authors, however, ap- peared ei.sewhere in print. It was not the intent of the authors of these descriptions to propose new taxa in this popular magazine (Taki and Habe, 1973:161). Nevertheless, their actions, though in- advertent, constituted nomenclaturai acts under the pro- \ isions of the International Code of Zoological Nomen- clature (ICZN, 1985, Articles 1 and 10-20) that resulted in some of these taxa being validh proposed in these first three numbers. Various workers ha\ e accepted, rejected, or ignored the availabilit\ of the names validK proposed in this magazine (Emerson, 1984; Coomans et ai, 1985; Coomans, 1986). As a result of conflicting views concerning the avail- ability of the new generic and specific taxa described in Numbers 1-3 of Pacific Shell Neivs, we have undertaken a review of the nomenclaturai status of these commonly overlooked taxa. It is beyond the scope of this paper for us to determine the correct scientific name (valid name, ICZN, 1985, Article 23a) for these taxa. For completeness we have also included a review of taxa proposed by Masaji Suzuki in Numbers 5 and 6 (No. 4 was not issued; Sadao Kosuge, in lilt., October 14, 1986), for some of these taxa are largeK unknown to workers owing to the rarit\ of the last two issues of Pacific Shell News (1972). The following abbreviations are used in the text: ICZN = International Code of Zoological Nomenclature; IMT = Institute of Malacology, Tokyo; NSMT = Na- tional Science Museum, Tokyo. In the Japanese text, scientific names were latinized unless indicated to have been derived from Japanese ideograms. In the case of nominal species for which the holot) pe v\as onl> illustrated in Pacific Shell News, we have reproduced the original illustrations. NOMENCLATURAL STATUS Ta,\.^ Considered in Number 1, J.\M ARY 20, 1970 Pacific Shell News, Number 1, i-iii + 41 pages; fron- tispiece in color, 18 photographs in black and white. Date of publication not given in this issue. Inaba and Oyama (1977) gave the date for the taxa cited by them in this munber as January 20, 1970. Despite the fact that Taki (1970:80) noted that he had received his copy on March W. K. Emerson and W. E. Sage, III, 1987 Page 195 1, 1970, Dr. Kosuge confirmed (in litt.. February 19, 1985) January 20, 1970 as the actual date of publication. 1. Conus coralinus Habe and Kosuge, p. i (color fron- tispiece), ii (Japanese text) (Conidae). This taxon was briefl\' discussed in the caption to the photograph. There is no indication that the authors proposed to describe this as a new species here or elsewhere; a nomen nudum. Nomenclatural status: Not a\ailable here. ValidK pro- posed as Rinzoconus coralinus Habe and Kosuge, 1970c. NOT Conus corallinus Kiener, 1845. Considered a junior synonym of C. klcmac (Cotton, 1953) by Walls (1979: 626, 627, 401) and Coomans et al. (1985:261). Conns coralinus (Habe and Kosuge, 1970) is a junior homonym of C. corallinus Kiener, 1845 (see Coomans et ai. 1985). 2. Latiaxis (Lamcllatiaxis) Habe and Kosuge, p. 7 (Coralliophilidae). A diagnosis for a new genus-group name was not provided for Lamellatiaxis, a nomen nu- dum. Nomenclatural status: Not axailable here. Lamella- tiaxis was validK proposed as a new subgenus b\ Habe and Kosuge (1970a:182), type species b> original desig- nation: Latiaxis (Lamellatiaxis) marumai Habe and Ko- suge, 1970. Kosuge and Suzuki (1985:23) subsecjuently placed Lamellatiaxis as a subgenus in the genus Babe- lumurex Coen, 1922. 3. Latiaxis [Lamellatiaxis) marumai Habe and Ko- suge, p. 7, 2 figs. (Coralliophilidae). The description of the species-group name L. (L.) marumai Habe and Ko- suge, 1970 in this number lacks a statement in the text that can satisfy the requirement to differentiate the species [ICZN, 1985, Article 13a(i)]; a nomen nudum. Nomenclatural status: Not available here. Validly pro- posed as Latiaxis (Lamcllatiaxis) marumai Habe and Kosuge, 1970a. Kosuge and Suzuki (1985:24) dated the availability of this taxon from the description in Venus. 4. Conus memiae Habe and Kosuge, p. 8, 2 figs., ho- lotype (Conidae). Text in Japanese compares this new species with C. japonicus (name in Japanese ideograms) and C. icakaijamaensis (name in Japanese ideograms) and morphologically differentiates this taxon. Nomenclatural status: Available here. Subsequently proposed as Asprella memiae Habe and Kosuge, 1970c. Kohn and Riggs (1979:140) dated the availability of this taxon from Pacific Shell News, Number 1. Walls (1979: 706) considered Conus (Asprella) adonis Shikama, 1971, to be a junior s)'nonym of this species. 5. Galeoastraea midwaijensis Habe and Kosuge, p. 9, 3 figs. (Turbinidae). Neither the Japanese nor English text makes a statement that purports to differentiate this "new species ; a nomen nudum. Nomenclatural status: Not available here. N'alidly pro- posed as Galeoastraea midwaijensis Habe and Kosuge, 1970d. 6. Claviscala midwayensis Habe and Kosuge, p. 10, 1 fig., holotype (Epitoniidae). The Japanese text com- pares this "new species with C. kuroharai (name in Japanese ideograms) and morphologicalh' differentiates this taxon. Nomenclatural status: Available here. Subsequently proposed as Claviscala midwaijensis Habe and Kosuge, 1970d. Ta.xa Considered in Number 2, April 30, 1970 Pacific Shell News, Number 2, i-iii -H 40 pages, fron- tispiece in color, 18 photographs in black and white. Date of publication April 30, 1970, indicated on inside of back cover; date verified by Inaba and 0>ama (1977), 1. Cijpraea (Ercjsaria) miijokoae Habe and Kosuge, p. i (color frontispiece; dorsal and apertural views of ho- lotype), ii (Japanese text) (Cypraeidae). The brief expla- nation in Japanese to the figures states in part "Unlike ordinary Cijpraea tigris [name in Japanese ideograms], this species is characterized by its scattered color dots which become darker and finer along the edge. And as it matures, the beaks at both ends become a beautiful purple-red. It was found in the South China Sea and was purchased in Taiwan. . . . We named ours [this species] in honor of the collector, Mr. Suzuki's wife. " In English: "Measurement: 41.5 x 27.0 mm. " The description, al- though admittedly brief, compares this taxon with Cij- praea tigris Linnaeus and purports to differentiate this species. Nomenclatural status: Available here. Inaba and Oya- ma (1977:78) cited this taxon as a manuscript name, "name and figure only, " On the other hand. Burgess (1985:271, pi. 20, c, not holotype) considered this taxon to be an available name. Burgess (1985) stated that he examined the holotype and he referred this taxon to the synon\my of C. tardus Lamarck, 1810, but we question the localit\ data, "Bashi Channel, ' cited b\ Burgess. The apparently mislocalized data were provided b\ a Tai- wanese shell dealer from whom the specimen was pur- chased. The depositors of the holotype has not been determined; the original illustrations are reproduced here (figures 6, 7). 2. Clavus regius Habe and .Murakami, p. 6. 2 figs., holotype (Turridae). The Japanese text states the new species is referable to the Turridae and briefly discusses some turrid genera. The English text repeats in part the description of the Japanese text: "This is the largest species belonging to the genus Clavus and collected from the Ryukyu mainland by Mr. Kina, the keen collector in Okinawa. The shell is solid and light [red-]brown with a series of [charcoal-jbrown nodules on the whorls. . . . Measurement: 54.5 x 23.3 mm. ' The description fulfills the provisions of the Code requiring a statement pur- porting to difterentiate a new species. Nomenclatural status: A\ailable here. The holot\pe (NSMT-Mo 53139) was illustrated by Inaba and Oyama (1977:101, pi. 7, fig. 11), who also mentioned the presence of two paratypes (XSMT-Mo 53143 and 53144). 3. Fulgoraria glabra Habe and Kosuge, p. 7, 2 figs., holot\ pe (N'olutidae) Text in Japanese compares this new^ species to F. leviuscula Rehder, 1969 and morpholog- ically differentiates this taxon. Nomenclatural status: Available here. Subsequently Page 196 THE NAUTILUS, Vol. 101, No. 4 Figures 1-7. RfpnuliicUuns ul urigiiial illustrations, x 1. 1, 2. Ctcnocuidia kmai llal)e and Murakann, 1970. 3. PhyUocoma neglecta Habe and Kosuge, 1970. 4. Conus kintoki Habe and Kosuge, 1970. 5. Conus spirofilis Habe and Kosuge, 1970. 6, 7. Cyprara (Erosaria) mUjnhoac Habe and Kosuge, 1970. W. K. Emerson and \V. E. Sage. Ill, 1987 Page 197 proposed as Fulgoraria (Fulgoraria) glabra Habe and Kosuge, 1970b. 4. Ctenocardia kinai Habe and Murakami, p. S. 2 figs., holot\pe (Cardiidae). The Japanese text compares this taxon with C. symbolica Iredale, 1928 and C. perornata Iredale, 1928. The Enghsh text states in part, "This new porcupine cockle has been brought from the Ryukyu mainland. . . . This is recognized b\ the shown w hite shell scattered flesh orange blotclies and armed b\ the spiny- ribs of about thirt\ -two in number. Ct. symbolica Iredale from the Philippines is the most closely allied species to this new species. . . . Measurement: 54.0 x 4,3.0 mm." Nomenclatural status: Available here. Inaba and Oya- ma (1977:62) recorded the presence ot the holot\'pe, NSMT-Mo 53149 and a paratype, NSMT-Mo 53150. The original illustrations are reproduced here (figures 1, 2). Ctenocardia victor (Angas, 1872) is a senior synonym of C. kinai Habe and Murakami, 1970, a taxonomic place- ment confirmed b\ Dr. Habe (in litt.. .^pril 29, 1987). 5. Conus kintoki Habe and Kosuge, p. 9, 1 fig., ho- lot% pe (Conidae). The status of this taxon was pre\iously discussed b\ the senior author and accepted as a validly proposed name (Emerson, 1984). Inaba and Osama (1977: 63) stated that the holotype (102.0 x 49.5 mm) is de- posited in the collection of Dr. Kosuge. We have been informed b\' Dr. Kosuge that the holot\ pe is neither in his collection nor that of Mr. Masaji Suzuki (in litt., October 14, 1986 and March 10, 1987). The original illustration is reproduced here (figure 4). Nomenclatural status: Available here. Kohn and Riggs (1979:139) dated the availability of this ta.xon from Pa- cific Shell News, Number 2. Conus kintuki Coomans and Moolenbeek (1982:136, 137, fig. 4) is a junior subjective svnonvm of this taxon, as pointed out b\' Emerson (1984: 59). 6. Conus (Parviconus) nadaensis .A.zuina and Toki, p. 30, 2 figs. (Conidae). The Japanese text is largeK devoted to an announcement of the independent discoveries of this new cone from off Kii, Japan b\ Koji Nomoto and by Masao Azuma and Raisaburo Toki. These newly found specimens were not compared \\ ith other species and no attempt was made to difterentiate this species; a nomen nudum. Nomenclatural status: Not available here. Validly pro- posed as Endemnoconus [sic] nadaensis Azuma and Toki, 1970. Tax.\ Considered in Number 3, October 30, 1970 Pacific Shell Sews, Number 3, i-iii + 38 pages, fron- tispiece in color, 26 photographs in black and white. Date of publication: October 30, 1970, indicated on inside of back cover. 1. Phyllocoma neglect a Habe and Kosuge, p. 7, 1 fig., holotype (Muricidae). An English translation of the Jap- anese text and other data relating to the proposal of this taxon were presented by Emerson and D'.Attilio (1979: 1, 2, figs. 17, 18, Philippine specimen) and need not be Figures 8-11. Reprnductioiis ot original illustrations: x ], 8. 9. Cornutoconas lamcUatus Suzuki, 1972. 10, 11. Homalo- poma striatum Suzuki, 1972. repeated here, as the description is \alidl\' proposed un- der the provisions of the Code. Nomenclatural status: .Axailable here. This taxon is referred to the genus Dermomurex Monterosato, 1890 by Emerson and D'Attilio (1979) and by Yokes (1985: 47, pi. 1, figs. 7a, b). Inaba and Ovama (1977:82) stated that the holotype (22.5 x 11.2 mm) is deposited in the collection of Dr. Kosuge. We have been informed b\ Dr, Kosuge that the holotspe is neither in his collection nor that of Mr. Masaji Suzuki (in litt., October 14, 1986 and March 10, 1987). The original illustration is reproduced here (figure 3). 2. Typhis ramosus Habe and Kosuge, p. 8, 2 figs. (Muricidae). The Japanese text discusses the typhid species known from Japan and describes this new species from the South China Sea as follows: shell solid, color light brown with darker spiral lines; varices four, sculptured with sharp spines and hollow projections, the terminal pipe being the largest and protruding laterall)' and slight- ly upward. The new species is compared with T. phili- pensis [sic] Watson [= Typhina philippensis (Watson, 1883)]. Nomenclatural status: Available here. SubsecjuentK proposed as Typhis ramosus Habe and Kosuge, 1971 (holotype, NSMT-Mo 38872). The original description was partially repeated in 1973 [Hawaiian Shell News Page 198 THE NAUTILUS, Vol. 101, No. 4 21(11):1 1, 2 figs,]. Iiiaha and Oyama ( 1977:103. pi. 0. fig. 6) also illustrated the holotvpe and recorded a parat\ pe, \SMT-Mo 39016). 3. Ginebis corolla Habe and Kosuge, p. 10, 1 fig , holot\pe (Trochidae). The Jajxmese te.xt discusses the distribution of regional species of Ginebis and compares this new species with them. The English text states: "This new species differs from the other two related forms in Japan (G. argenteonitens and G. hirasei) in its broader shell w idth, beaded granules of each whorl and number of spiral threads on the base of body whorl. The [two] specimens were collected from the South China Sea at a depth of about 200 m[eters] Measurement: 49.5 x 39.5 mm." Nomenclatural status: Available here. Inaba and Oya- ma (1977:33, pi. 6, fig. 3) illustrated the holotype (NSMT- Mo 45547). Subsequently described as Ginebis hamadai Kosuge, 1980 (holotype,' IMT-80-5). 4. Cuniis spirofilifi Habe and Kosuge, p. 11, 1 fig., holotype (Conidae). The Japanese text compares this new species with C. hirasei and morphologically differentiates this taxon. The English text states: "This pretty new cone shell was collected from the South China Sea and more than five specimens had been brought to Japan. It is easily distinguished [from C. hirasei (Kira)] for its spiral color striae, dark brown color bands and irregular white patches. . . . Measurement: 30.8 x 16.7 mm." Nomenclatural status: Available here. Inaba and Oya- ma (1977:116) and Kohn and Riggs (1979:144) dated the availability of this taxon from Pacific Shell Netvs, Num- ber 3. Inaba and Oyama (1977) stated that the holotype is deposited in the collection of Dr. Kosuge. We have been informed by Dr. Kosuge that the holotype is neither in his collection nor that of Mr. Masaji Suzuki (in Hit., October 14, 1986 and March 10, 1987). The original illustration is reproduced here (figure 5). Validly Proposed Ta.xa in Number 5, September 5, 1972, in "Descriptions of Two New Species of Gastropods" BY [Mas.\ji] Suzuki Pacific Shell News, Number 5, four unnumbered pages, two black and white photographs. Date of publication: indicated on iourth page as May 31, 1972. However, the actual date of publication was September 5, 1972 (Ko- suge, 1985:4). In the Japanese text on the fourth page, Masaji Suzuki stated that Number 5 was being sent as a combintd issue for Numbers 4 and 5. It should be noted that the Pacific Shell (;lub, in May, 1971, sponsored an exhibition of shells in Tokyo and issued on this occasion an illustrated catalog pertaining to the shells on displav . No new taxa were proposeti in this catalog, "Jewels oi the Sea: Seashells of the World." This publication cannot be construed to be Pacific Shell News, Number 4, which was never published (Kosuge, hi lift.). 1. Cornuioconus Suzuki, first and second pages, type species bv original designation, Cornutucunus lamella- tns Suzuki, 1972. For taxonomic status, see remarks be- low, 2. Cornutoconus kunellatus Suzuki, second page, text fig. 1 (two views of holotype) (Conidae). Tv pe locality: off Sumisu Isle, near Hacliijo Id.. Izu Islands, in about 300 meters, South China Sea. The holotype (18.4 x 1 1,0 mm) and a paratype (16.7 x 8.7 mm) from the Maruma Collection are stated to have been deposited in the NSMT. The original illustrations are reproduced here (figures 8, 9). Remarks: According to Taki and Habe (1973:161), Coomans et al. (1983:114), and Kosuge (1985:4), Cor- nutoconus lamellatus Suzuki, 1972 is a junior synonym of Tarantecunus chiangi Azuma, 1972. ConsequentK , Cornutoconus Suzuki. 1972 is also a junior synonym of Taranteconus ,\zuma, 1972, because the type species by original designation is Taranteconus chiangi Azuma, 1972. Therefore, Taranteconus and T. chiangi have priority over Cornutoconus and C. lamellatus. respec- tively. 3. Honialopoma striatum Suzuki, third page, text fig. 2 (three views) (Turbinidae). Type locality: same as for Cornutoconus lamellatus. The holotvpe (12.2 x 11.4 mm)and a parat>pe (11.2 x 10.6 mm) from the Maruma collection are stated to have been deposited in the NSMT. The original illustrations are reproduced here (figures 10, 11). Remarks: According to Taki and Habe (1973:161 ) and Dr. Sadao Kosuge {in litt., February 19, 1985), Homa- loponia striatum Suzuki, 1972 is a junior synonym of H. eoa Azuma, 1972. Validly Proposed Taxa in Number 6, December 1, 1972, in "Descriptions of New Species of Laii.wis" BY Masaji Suzuki (first three pages) Pacific Shell News, Number 6, four unnumbered pages, two black and white photographs. Date of publication: indicated on fourth page as December 1, 1972, 1, Latiaxis [sensu stricto) longispinosus Suzuki, first and second pages, text fig. (two views of holotv pe) (Cor- alliophilidae). Type locality: off Onna, Okinawa Main Island. Okinawa'Pref,, Japan, The holotype (32.4 x ,39.6 mm) from the Suzuki Collection is deposited in the IMT (85-17) (fide Kosuge & Suzuki, 1985:15). Remarks: Kosuge and Suzuki (1985:15) referred this taxon to the genus Babelomurex Coen, 1922, and con- sitlered it a senior synonym of Latiaxis pisori D .Attilio and Emerson, 1980. Mr. D'.-\ttilio and one of us (\\'.K.E.) afford L. pisori full specific status on the basis of mor- phological differences of the spire and spines of these two nominal species (see D'Attilio, 1985:98-100, figs. 1- 4, for additional comments on L. pisori). 2. Latiaxis {Rahclomurcx) pagodas perrernicosus Su- zuki, second and third pages, text fig. (holotvpe and paratvpc) (Coralliopliilidae). T> pe localitv': off Ogasa- wara Islands (Bonin Ids.), in 200 meters. The holotvpe W. K. Emerson and W. E. Sage, III, 1987 Page 199 (23.5 X 22.3 mm) from the Suzuki Collection is deposited in IMT (85-18) (fide Kosuge & Suzuki, 1985:16). Remarks: Kosuge and Suzuki (1985) raised this ta.xoii to lull specific standing in the genus Babclunnin'x. ACKNOWLEDGEMENTS We are greatK indebted to Ms. Nancy Broschart for contributing an English translation of pertinent passages of the Japanese texts. Without her enthusiastic cooper- ation we could not have undertaken this review. Mr. Masao Tabakotani generously provided a translation of relevant pages of the catalog for the 1971 shell exhibition. We thank Dr. Sadao Kosuge for generousK providing us with original copies of Pacific Shell News and for an- swering numerous questions regarding its publication. We also thank Dr Tadashige Habe for his informative correspondence on this subject. LITERATURE CITED Azuma, M. 1972. Descriptions of four new gastropods from South China Sea. Venus 31(21:5.5-61. 10 figs. (July 30), Azuma, M. and R. Toki. 1970. Description of a new cone from Kii Peninsula. Honshu, N'enus 29(3):77-80, 4 figs. (Aug. 31). Burgess, C. M. 1985. Cowries of the world, Seacomber Pub- lications, Cape Town, i-XVlI -I- 289 p,, illus, Coomans, H. E. 1986. Old and new names in the Cnnidae. Hawaiian Shell News 34(10):7, 8, 3 figs. Coomans, H, E. and R. G. Moolenbeek, 1982, Studies on Conidae (Mollusca, Gastropoda) 1, Conus paptiensis and C. kintoki. two new species from deeper water in the western Pacific. Bulletin Zoologisch Museum L ni\ersiteit van Amsterdam S(15):133-l;38, 6 figs. Coomans, H. E„ R. G. Moolenbeek, and E. Wils. 1983, Al- phabetical revision of the (sub)species in Recent Conidae, 6, cahritii to cinereus. Basteria 47(5-6):67-143, figs. 293- 430. Coomans, H, E,. R, G, Moolenbeek. and E, Wils, 1985 Al- phabetical resision of the (sub)species in Recent Conidae, 7, cingulatus to cylindraceus. including Conus shikamai nomcn novum. Basteria 48(6):223-311, figs, 431-581. D'Attilio, A. 1985. A note on Latiaxis pisori D'Attilio and Emerson, 1980. The Festivus (San Diego Shell Club) 17( 10): 98-100. 4 figs. Emerson, W. K. 1984. C'oi)!(.s Ain/oAi Habe and Kosuge, 1970: a validly proposed taxon. The Nautilus 98(2):58-60, 3 figs. Emerson, W, K, and .A, D'Attilio, 1979, Six new species of muricacean gastropods. The Nautilus 93(1):1-10, 18 figs. Habe, T. and S. Kosuge. 197Ua. Description ol new subgenus and species of Laiiaxis from the South China Sea. Venus 28(4):182-185, 3 figs. (Jan. 31). Habe, T. and S. Kosuge. 1970b. Description of iieu species of Fulgoraria from the South China Sea, Nenus 29(1):1- 3, 2 figs, (May 15), Habe, T, and S, Kosuge. 1970c. Descriptions ot two new species ol cone shell from the Philippines and Taiwan, Venus 29(3):81-83, pi, 5 (Aug. 31). Habe, T. and S. Kosuge. 1970d. Descriptions ot three new gastropods from the sea around Midwav. N'enus 29(3):87- 91, pi, 6 (Aug, 31), Habe, T, and S, Kosuge, 1971, New typhid species from South China Sea. The Nautilus 84(3):82-83, 2 figs. (Jan. 25), [Article partially reprinted in Hawaiian Shell News 21(11): 11, 2 figs,, 1973.] Inaba, T. and K, Oyama, 1977, C^atalogue of molluscan taxa described by Tadashige Habe during 1939-1975, with il- lustrations of hitherto unfigured species, Tokyo. 184 p., 7 pis. International Commission on Zoological Nomenclature. 1985. International code of zoological nomenclature, 3rd ed. London, xx -I- 338 p. Kohn, A. J. and A. C. Riggs. 1979. Catalogue ol Recent and fossil Conus. 1937-1976, The Journal of Molluscan Studies 45(1):131-147, Kosuge, S, 1980, Description of new species of the genus Ginchis from the South China Sea (Trochidae, Gastropo- da). Bulletin of the Institute of Malacologv Tokvo 1(3):40, pi. 9, figs. 1-3. Kosuge, S. 1985. C7n(jngior/(;;iic//(;((i,s':' Hawaiian Shell News :33(8):4, Kosuge, S, and M, Suzuki, 1985, Illustrated catalogue of La- tiaxis and its related groups, Famib Coralliophilidae, In- stitute ot Malacolog) of Tok\o, Special Publication No, 1, 83 p,, 50 pis, Rehder, H, A, 1969, New species and subgenera of X'olutidae (Fulgorariinae) from the South China Sea and Japan, N'e- nus 27(4):127-132, pi, 7. Shikama, T, 1971. On some noteworthy marine Gastropoda from southwestern Japan (III). Science Reports of the Yo- kohama National University (II), 18:27-35, pi. 3, 2 text figs, Taki, I, 1970, [Notes on Pacific Shell Club] Venus 29(3):80 (Aug, 31), Taki, I, and T. Habe. 1973. [Review and .abstract] Venus 31(4):161 (Jan, 30), Vokes, E. H. 1985. The genus Dermomurex (Mollusca: Gas- tropoda) in Australia. Journal of the Malacological Society of Australia 7(l-2):45-65, 3 pis. Walls. J, G. 1979. Cone shells, a synopsis of the living Conidae. T F.H Publications, Inc., Neptune City, NJ, 1011 p . illus. THE NAUTILUS 101(4):200-206, 1987 Page 200 A New Ecphora Fauna from Southern Florida Edward J. I'eluch Department of Geology Florida Atlantic University Boca Raton, FL 33431, USA ABSTRACT A species radiation of the extinct rapanine thaidid genus £f- phora Conrad, 1843 is reported from the lowermost beds of the Pliocene Buckingham Formation (= Pinecrest Beds of Ols- son) at Sarasota, Florida. Five Ecphora species were collected together in the basal units (Units 10 and 11 of Petuch, 1982) of the Macasphalt Newburn Pit Mine, and these constitute the richest Ecphora fauna ever reported from one localit\ . Of these five species, three were previous!) described; Ecphora qitad- ricostata (Say. 1824) and E. parvicostata Pilsbrv, 1911, which range from Virginia to Florida, and E. striatula Petuch, 1986, which is confined to southern Florida. Two species, £. bradleijae and E, hrrtirccknrum. are described as new INTRODUCTION In the late 1960's, a new molluscan paieontological re- source opened near Sarasota, Florida. This site, the Mac- asphalt Newburn Pit Mine #0800826 (formerly the "Warren Brothers Shell Pit ) is dug entirely into the Pliocene Buckingham Formation (Mansfield, 1939; = Pinecrest Beds of Olsson, 1968; Petuch, 1986). This lo- calit\ has proven to be one of the most important pa- ieontological collection areas in peninsular Florida. The pit mine is unusual for Florida because of its large size and in that it is continuously pumped, preventing filling b\ groumiw ater and allowing for in-place collecting down to 70 foot depths (21 m). The remarkable richness of the Sarasota molluscan fauna far surpasses that of any other known Pliocene fauna in the eastern United States. To date, I have collected over 600 species of gastropods from the quarry, of which at least half are estimated as being new to science (Petuch, 1982). A preliminary survey of the faunas and stratigraph\' of the Macasphalt Pit Mine has shown that there are 11 fossiliferous beds or members expo.sed in the quarry. A stratigra|)liic arrangement of numbered imits, starting at the top and w orking dow n\\ ard (since the quarry is being deepened), was given in my earlier paper on the Sarasota pit mine (Petuch, 1982). The upper beds (Units 1-9) contain a typical, although e.\lremel\ rich, warm water Pliocene faima that has man\ elements in common with the upper beds of the Yorktown F'orniation of Virginia and northern North Carolina, the Duplin Formation of the Caroliiias, and the upper bed of the Jackson Bluff Formation of northwestern Florida (the "Cancellaria Zone of Mansfield, 1930). These formations ha\e been shown to be contemporaneous (Hazel, 1983). The basal beds of the quarry (Units 10 and 11), however, contain a very different molluscan assemblage with several species of the e.xtinct rapanine thaidid genus Ecphora Conrad, 1843. The fauna of these lowermost imits resembles those of the lower beds of the Yorktown Formation and the "Ecphora Zone" of the Jackson Bluff Formation (Mans- field, 1930). Unlike the northern Florida Pliocene beds, which most often contain a single, often poorly preserved, species of Ecphora. the basal units of the Buckingham Formation at Sarasota contain a well-preserved and richer fauna. Altogether, five species have been collected from these lower units. This is the richest single Ecphora fauna pres- ently known from any formation, surpassing that of the Miocene beds of Chesapeake Ba\ . The five species of the Buckingham Formation may possibly represent the last Ecphora species radiation; the "last gasp" of a group that died out at the end of the Pliocene. In this paper, the Sarasota Ecphora radiation is de- scribed for the first time, as are two new Ecphora species. Institutional abbreviations used here include: USNM (National Museum of Natural Historv, Smithsonian In- stitution, Washington, DC); MCZ (Museum of Com- parative Zoology, Harvard University). SYSTEMATICS Family Thaididae SubfamiK Rapaninae Genus Ecphora Conrad, 1843 Ecphora quadricostata (Say, 1824) (figures 10-12) Fusus 4-coslatm Say, 1824:127, pi. \'ii, fig. 5. Fiisus quadricostatns Conrad, 1830:211. Ecphora quadricostata Conrad, 1843:310, Cohis qiiadricostatus Tuome\ anil Holmes, 1857: 149, pi. xxx, fig. 4. Ecphora quadricostata unilnlicata (Wagner) Mansfield, 1930: 70-71, pi, 17. fig. 7. E. J. Petuch, 1987 Page 201 Ecphora quadricostata Olsson, 1968:73-75. pi, 1. fig. 1. Ecphora (iiiadricustata Wilson. 1987:23-25. Material examined: Two specimens, lengths 30 mm and 52 mm (incomplete). Unit 11 of Macasplialt Pit Mine #0800826, Sarasota, Florida, paleontology collection of Department of Geolog\ , Florida Atlantic University; length 29 mm, spoil pile from construction dig. Cape C:oral, Lee County, Florida, MCZ 29453 (figures 11, 12); length 60 mm. Unit 11 of Macasphalt Newburn Pit Mine, Petuch collection. Discussion: .Although Ecphora quadricostata is com- mon in the Yorktown and Duplin formations, it is rela- tiveK' rare in southern Florida, with onl\' one previous pictorialK documented example (Olsson, 1968: pi. 1, fig. 1 ). The paucit\' of specimens of E. quadricostata in south- ern Florida may reflect paleotemperature preferences, \\ ith E. quadricostata having preferred the cooler water temperatures of the mid-.-\tlantic region and the closeK- related E. hertweckorum new species and £. striatula Petuch, 1986 having preferred the tropical lagoonal and coral reef environments of peninsular Florida. Ecphora quadricostata differs from its Floridian rel- atives, E. hertweckorum and £. striatula. in being stocki- er and heavier, with small but noticeable "T-shaped flanges on the ribs (figure 19). Specimens examined from \'irginia. North Carolina, and Florida, all had one or two grooves on each rib. These grooves, which are arranged medially, give the rib a bisected appearance. The closely- related £. hertweckorum lacks these grooves. Occasional specimens of E. quadricostata show a fifth, smaller rib around the base of the siphonal canal, but this fifth rib is never ecjual in size to the other ribs. Wilson (1987) recenth' resolved some of the taxonomic problems revolving around E. quadricostata. He dem- onstrated unequivocabK' that £. quadricostata is a Plio- cene species, t\ pically from the Yorktown Formation, and that the Maryland Miocene species referred to this taxon b> Martin (1904) was actually a new species, which he named £. gardnerae. Wilson also showed that the taxon £. quadricostata umhilicata "Wagner" (of au- thors), often applied to Floridian specimens of £. quad- ricostata (i.e.. Mansfield, 1930), is a s\nonym of £, quad- ricostata. Ecphora parvicostata Pilsbry, 1911 (figures 8, 9) Ecphora parvicostata Pilsbry. 1911:438-439; Wilson, 1987:23. Material examined: Two specimens, lengths 92 mm and 30 mm (ju\enile). Unit 11 of Macasphalt Pit Mine #0800826, Sarasota, Florida, MCZ 29452; length 101 mm (figured here), same locality, Petuch collection. Discussion: Ecphora parvicostata has the most inflated shell and least developed ribs of the known Floridian Ecphora species. In cross section (figure 16), the ribs are rounded in shape and are adherent to the body whorl. As in £. quadricostata. the ribs of £. parvicostata also are marked with a medial grooxe, giving the rib a bi- sected appearance. Unlike £. quadricostata, E. parvi- costata is an intricateU' sculptured species when voung, becoming smoother and less sculptured as it matures. The 30 mm ju\enile specimen listed abo\e (MCZ 29452) has numerous large spiral cords and intermittent pitlike depressions between the ribs. The shoulder of the juvenile £. parvicostata is also distinctK rounded. Conversely, the 29 mm juvenile £. quadricostata listed previously (MCZ 29453) is smooth between the ribs, as in adults, and has an angled shoulder. The biogeographic and stratigraphic ranges of £. parvicostata are still in debate, as the type locality given by Pilsbr\ (1911) appears to be in error. The three spec- imens in Pilsbry s type lot were mixed in with specimens of £. tricostata Martin, 1904, and since that species is only known from the Miocene, and mostly from Mary- land, Pilsbr\ assumed that his £. parvicostata was also from the Chesapeake Miocene. Since the collector was unknown, no more information about the type locality could be gathered. Subsequent extensive collecting in the Miocene formations of Marvland (Calvert, Choptank, Little Cove Point L'nit, and St. Mary's), Virginia (East- over) (Ward and Blackwelder, 1980), and North Car- olina (Pungo River), have failed to uncover any large Ecphora species that e\en remoteh' resemble £. parvi- costata. The finding of three specimens of £. parvicostata in the Buckingham Formation at Sarasota documents the species as being Pliocene in age. Dr. EmiK Yokes (per- sonal communication) told me of two specimens of £. parvicostata in the Tulane Universit\ paleontolog\- col- lections, one from the Yorktown Formation at Rice's Pit and the other from the Jackson Bluff Formation of north- ern Florida. These tw o specimens further support a Plio- cene age for the species Wilson (1987) also stated that £. parvicostata "must come from \irginia ', but consid- ers it "only an extreme variation of £. quadricostata". Considering the great differences in the juvenile shells of £. quadricostata and E. parvicostata and the larger size and more inflated body whorl of the adult £. parvi- costata. I belie\e that the two species are distinct, albeit closely related. All three Sarasota specimens of £. parvi- costata differ from Pilsbry s type in having five ribs in- stead of four, but are otherwise identical in form. Ecphora striatula Petuch, 1986 (figure 13) Ecphora striatula Petuch, 1986:406, pi, 3, figs. 15, 16, Material examined: Holot\ pe, length 31 mm. Unit 10 of Macasphalt Pit Mine #0800826, Sarasota, Florida, MCZ 29225; paratv pe (fragment of spire), length 1 1 mm, "Lakes of the Meadows subdivision. Bird Road, western Metropolitan Miami, Dade County, Florida, from 20 m depth dredge site, MCZ 29235; length 70 mm, encased in limestone, from boulder along Tamiami Trail near Ochopee, Collier County, Florida, Petuch collection, il- lustrated here. Page 202 THE NAUTILUS, Vol. 101, No. 4 E. J. Petuch. 19S7 Page 203 Page 204 THE NAUTILUS, Vol. 101, No. 4 Discussion: Morphologicall) , tlie closest species to Ec- phora striatitla is £. hertweckonim. The differences between the two species are discussed under E. hert- weckorum. Although contemporaneous with E. hert- weckonim. E. striatula appears to have had different ecological preferences, and the two species have not been collected together. At Bird Road in Miami, £. striatula (fragmentary paratype) was collected along with massive reef corals and a large fauna of coral reef-associated mollusks (Petuch, 1986). The Tamiami Trail specimen was found encased in a block of reefal limestone, also indicating that E. striatula inhabited coral reefs. The holot)pe of £. striatula from Sarasota, although not found along with massive reef corals, was collected in a dense biohermal assemblage of the interlocking branching coral Septastraea crassa (Holmes, 1858) in the Macasphalt Pit. Ecphora hertweckorum, on the other hand, appears to have been a lagoonal, soft substrate species, and is usually found together with the large lagoonal bi\alves Chesapecten septenarius (Say, 1824) and Carolinapecten eboreus (Conrad, 1833). Ecphora striatula can be considered an index fossil for the fossil reefs and bioherms of the oval-shaped "Everglades Pseu- doatoll" (Petuch, 1986, 1987). Ecphora bradleyae new species (figures 1-6) \Iateriai examined: HOLOTYPE — length 66 mm. Unit 10 of Macasphalt Newburn Pit Mine #0800826, Sarasota, Florida, USNM 358548; PARATYPES— length 33 mm, same locality as holotvpe, MCZ 29447; length 76 mm, same localit) as holot\pe, MCZ 29449; fragment, 95 mm, same locality as holotype, MCZ 29450; 3 specimens, lengths 85-105 mm, same locality as holotype, Petuch collection. Description: Shell turbinate in form, thickened, with 4 wide, flattened spiral ribs on body whorl; ribs strongly "T-shaped in cross section (figure 20); some specimens with ribs almost touching along edges; ribs ornamented with 4-8 fine, incised grooves; shell smooth and unor- iiamented between and beneath grooves; shoulders rounded; spire elevated, with sloping outline; columella adherent; umbilicus open, flaring; siphonal canal well developed; aperture moderate in size for genus, round in shape; spire whorls with 2 ribs per whorl; suture and edge of shoulder rib separated b\ wide space, gi\ing spire tabulate appearance; calcitic outer shell layer col- ored cream-tan or reddish-gray. Range: Known onK from L nit 10 of the Macasphalt Newburn Pit Mine #0800826, Sarasota, Florida. Buck- ingham Formation, early Pliocene. Etymology: Named for Mrs. Evelyn Bradle\ , of Bra- denton, Florida, who collected the holotype. Discussion: Ecphora bradleyae differs from the other known members of the genus in having extremeK' well developed "T"-shaped ribs, and in having a more round- ed, fusiform outline. The flanges of the "T"-shaped ribs of some specimens almost coalesce (such as in the para- t) pe shown here in figure 7), in effect producing a double shell. This may have been an anti-crab predation ad- aptation; doubling the effective shell thickness without doubling the shell w eight, and therefore, making it more difficult for peeling crabs, such as Menippe. to break back the outer lip. The small paratype (figures 3, 4) has a large healed break that probabK resulted from an unsuccessful crab attack. Ecphora hertweckorum new species (figures 14, 15) Material examined: HOLOTYPE — length 50 nun (missing siphonal canal). Unit 11, Macasphalt Pit Mine #0800826, Sarasota, Florida, MCZ 29448; PARA- TYPES— 3 fragmentar\ specimens, lengths 35-47 mm, same locality as holotype, MCZ 29451; length 90 mm (fragmentary), same localit\- as holot\pe, Petuch collec- tion. Description: Shell inflated, thin, delicate; body whorl w ith 4 vers thin, greatly-projecting, bladelike spiral ribs; ribs (figure 17) rounded along edges w ithout "T -shaped flange; shoulder sharpK angled; spire ele\ated, scalari- form; spire whorls with 2 ribs per whorl; shell smooth between ribs, without sculpturing; umbilicus wide, flar- ing; calcitic outer shell la\er colored cream to yellowish- tan. Range: Known onl\ from L nit 11 in the Macasphalt Newburn Pit Mine #0800826, Sarasota, Florida. Buck- ingham Formation, early Pliocene. The fragment illus- trated by Olsson and Petit, 1964 (as "Ecphora quadri- Figures 1-7. Ecplwra bradleyae new species, from Unit 10 in the Macasphalt Newbnrn Pit Mine, Sarasota, Florida 1. 2. Il(ilot\pe, 66 mm, USNM 358548, 3, 4. Paratvpe, 33 mm, Mt:Z 29447. .5. 6. Parat\pe, 103 mm. Petuch collection. 7. Parat\pe, 76 mm, MCZ 29449. Figures 8-15. 8, 9. Ecphora parvicostata Pilsl)r\. 1911. 92 mm, Macasphalt Newburn Pit Mine. Unit 11. 10. Ecphora quadricostala (Say, 1824), 30 nun (broken). Macasphalt Newburn Pit Mine, I'nit 11, 11, 12. Ecphora quadricostala (Sa\, 1824), 29 mm, C:ape Coral, Lee Co., Florida, MCZ 29453. 13. Ecphora striatula Petuch, 1986, 70 nun (partialK covered with limestone and barnacles), along Tamiami Trail near Ochopee, Collier Co., Florida. 14, 15. Ecphora hertweckorum new species, holotype, 50 mm (incomplete), Macasphalt Newburn Pit Mine, Unit 11, MCZ 29448. E. J. Petuch, 1987 Page 205 m i 16 17 18 19 20 Figures 1 6-20. Cross sections of the ribs of Floridian Ecphora species. 16. Ecphora parvicostata Pilsbry, 1911. 17. Ecphora hcrtwcckorum new species. 18. Ecphora striatula Petuch. 1986. 19. Ecphora quadricostata (Sa\, 1824). 20. Ecphora bradleyae new species. coatata umbilicata Wagner ", pi. 82, fig. 7), from Pinecrest, Collier CouiitN , Florida, ma\ be this species. Etymology: Named for Mr. and Mrs. Charles (and Vi- olet) Hertweck of N'enice, Florida, in recognition of their extensive fossil collecting around southern Florida, which has resulted in the discovery of many new species. Discussion: Ecphora hertweckoriun is most similar to the contemporaneous £. striatula Petuch, 1986 (figure 13). That species, howe\er, differs in being more inflated, ovate, and lower spired, in being hea\il\ sculptured with numerous raised threads between the ribs and on the siphonal canal, and in having flattened edges on the ribs. Ecphora hertweckoriun is characteristically unorna- niented with no sculpturing between the ribs or on the siphonal canal, and has rounded edges on the ribs. The spire of E. hertweckorum is also more elevated than that of E. striatula, and has an obvious stepped appearance. From the ubiquitous E. quadricostata (figures 11, 12), E. hcrtwcckorum differs in being a much thinner, much more inflated shell with more prominent, bladelike ribs. Besides being thinner and more fragile, the ribs of E. hcrtwcckorum lack the obvious "T "-shaped flanges seen on the ribs of E. quadricostata. Ecphora hcrtwcckorum is very similar both in shell shape and in the structure of the ribs, to the un-named species from the Miocene Choptank Formation of Maryland that was illustrated by Martin (1904: pi. LII, fig. 4). Although Martin referred the Choptank species to the taxon "Ecphora quadricos- tata var. umbilicata (Wagner)"', Wilson (1987) has shown that that name is referable to the Pliocene E. quadri- costata, leaving the Choptank species nameless. The thin- ribbed Choptank species, which Martin described as hav- ing ribs that were not "T-shaped and as being thinner than typical E. quadricostata (and presumably E. gard- nerae). may be the direct ancestor of £. hertweckorum. If that is the case, then there may be separate evolu- tionar\ lineages for both the thin-ribbed species and those with "T-shaped ribs. KEY TO THE FLORIDIAN ECPHORA SPECIES The shape, size, arrangement, and degree of de\elop- ment (projecting from the body whorl) of the ribs on Ecphora species are consistent and important taxonomic characters. The rib shape is liest seen in cross section (figures 16-20) or in profile at the edge of the aperture. On a few species, secondary sculpturing on the body whorl between the ribs is also an important taxonomic character. See Wilson (1987) for a review of the genus. la. Ribs depressed, adherent, cordlike, rounded (fig- ure 16) E. parcicostata lb. Ribs elevated, [jrojecting from bod\ whorl (fig- ures 17-20) ". .' r. . .2 2a. Ribs very thin, bladelike, with rounded edges (figure 17); body whorl smooth . . . £. hertweckorum 2b. Ribs very thin, bladelike, with squared edges (figure IS); body whorl sculptured with spiral threads E. striatula 2c. Ribs with laterally-expanded terminal flanges (figures 19, 20) . . ' 3 3a. Ribs with slightK -developed terminal flanges; slightly "'T""-shaped in cross section (figure 19) E. quadricostata 3b. Ribs with greatly-developed, broad terminal flanges; distinctK "T"'-shaped in cross section (figure 20) E. bradleyae ACKNOWLEDGEMENTS I thank Mr. and Mrs. Charles Hertweck of Venice, Flor- ida for the kind donation of the type of Ecphora hert- weckorum and for specimens of E. parvicostata and E. bradleyae. I also thank Ms. Mary Mansfield of St. Pe- tersburg, Florida for the generous donation of specimens of E. bradleyae, E. hcrtwcckorum. and E. quadricostata. Dr. M. G. Harasewych took the photographs used in this paper. Mr. Donald Asher of Mechanicsville, Maryland, assisted in the collection of much of the material studied Finally, I give special thanks to the ow ners (Ashland Oil Co.) and management of the Macasphalt New burn Pit Mine, Sarasota, Florida, for allowing me to collect on their propert)- and for their assistance during my research in the quarr\ o\er the past 8 )ears. LITERATURE CITED Conrad, T. A. 1830. On the geology and organic remauis of a part of the peninsula of Maryland; with appendix. Jour- nal of the Academy of Natural Sciences of Philadelphia 6:205-230, pis. 9, 10. Conrad, T. A. 1843. Descriptions of a new genus, and of twenty-nine new Miocene, and one Eocene fossil shells of the United States Proceedings of the .\cadem\ of Natural Sciences of Philadelphia 1305-311. Hazel, J. F. 1983. Age and correlation of the Yorktown (Plio- cene) and Croatan (Pliocene and Pleistocene) formations at the Lee Creek Mine. In: Ra\, C. (ed). Geology and paleonlologN of the Lee Creek Mine, North Carolina, I. Smithsonian Contributions to Paleobiologv 53:81-122, 38 pis, Mansfield, W. C. 1930. Miocene gastropods and scaphopods of the Choctaw hatchee Formation of Florida. Florida State Geological Survey, Bulletin 3:1-190, 21 pis. Mansfield, W. C. 1939. Notes on the Upper Tertiary and Page 206 THE NAUTILUS, Vol, 101, No. 4 Pleistocene Mollusks of Peninsular Florida State of Florida Department of (Conservation, Geological Bulletin 18:7-16, table 1. Martin, G. C. 1904. S\stematic paleontology: Gastropoda. Maryland Geological Survey, Miocene, p. 131-270, pis. 39-63. Olsson, A. A. 1968. A review of the Late Cenozoic stratig- raphy of southern Florida. In: Perkins, R. D. (ed.). Late Cenozoic stratigraphy of southern Florida — a reappraisal. Miami Geological Society, p. 66-82, 2 pis. Olsson, A. A. and R. E. Petit. 1964. Some Neogene Mollusca from Florida and the Carolinas Bulletins of American Paleontologv 47(217):.309-.57.5, pis. 77-83. Petuch, E. J. 1982. Notes on the Molluscan paleoecology of the Pinecrest Beds at Sarasota, Florida with the description of Pyruella, a stratigraphically important new genus (Gas- tropoda: Melongenidae). Proceedings of the Academy of Natural Sciences of Philadelphia 134:12-30, 3 figs,, 3 pis, Petuch, E, J, 1986, The Pliocene reefs of Miami: their geo- morphological significance in the evolution of the Atlantic Coastal Ridge, southeastern Florida, U.S.A. Journal of Coastal Research 2(4):391-408, 5 Bgs., 4 pis. Petuch, E. J. 1987. The Florida Everglades: a buried p.seu- doatoll':' Journal of Coastal Research 3{2): 189-200, 9 figs. Pilsbry, H. A 191 1. .A new Ecphora of the Chesapeake Mio- cene Proceedings of the .\cadem\' of Natural Sciences of Philadelphia (May):438-439, fig. 1. Sa> , T. 1824. An account of some of the fossil shells of Mary- land. Journal of the Academy of Natural Sciences of Phila- delphia 4:124-155, pis. 7-13. Tuomey, M. and F. S. Holmes. 1857. Pleiocene fossils of South-Carolina. James and Williams, Printers, Charleston, p. i-.\vi, 1-152, 30 pis. Ward, L. W. and B. W. Black weliler. 1980. Stratigraphic revision of L pper Miocene and Lower Pliocene beds of the Chesapeake group. Middle Atlantic Coastal Plain. L'.S. Geological Survev Bulletin 1482-D (Contributions to Stra- tigraphy), 61 p., 25 figs., 5 pis. Wilson, D. 1987. Species of Ecphora. including the subgenus Stenomphalus, in the Pungo River Formation. In: Ray, C. (ed.). Geology and paleontology of the Lee Creek Mine, North Carolina, II. Smithsonian Contributions to Paleo- biology 61:21-29, 1 fig.. 2 pis. n I, fl INSTRUCTIONS TO AUTHORS THE NAUTILUS publishes papers on all aspects of the biology and systematics of mollusks. Manuscripts de- scribing original, unpublished research as well as review articles will be considered. 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