MBL/WHOl THE NAUTILUS Volume 102 1988 AUTHOR INDEX Absalao, R. S. Adams, W. F Askew, T. A. AUFFENBERG, K AUFFENBERC, T BlELER, R. Boss, K. J. bouchet, p Collins, T. M D'AsARO, C. N DAtiilio, A DuShane, H. Emerson, VV. K. Gerberich, a. G. Gordon, M. E. Haimovicl M. Harasewych, M. G. Hayek. L. C Hershleb, R. Kabat, a. R. KiLGOUR, B V\'. 36, M. B. 99 Lee. H. G. 125 Mackie. G L 89, 92 McKiNSTRY. D M 40. 154 McLean, J. H 40 \1endl. W. 1 MlKKELSEN, P 115 Moore, D. R. 149 Myers, B. W. 102 o'sullivan, j. 1.34 Pawlik. J. R. 106 Petit, R. E. 30 Pip, E. 110 POLACO, O. J 125 POMPONI, S. .\. 123 RoMER, N. S. 82 Sage, W E , III , 92 DOS Santos Cruz, R. L. 56 Smith, DC 56 Snyder, MA 164 Thompson, F. G. 73 Vermeij, G. J 78, 154 73 127 99 129 1 131 102 47 47 130, 164 65 129 92 131 36, 110 99 155 54 78 102 NEW TAXA PROPOSED IN VOLUME 102 (1988) GASTROPODA Perotrochus charlestonensis Askew, new species (Pleurotomariidae) Macrarcnc difiilala McLean. Absalao and Santos Cruz, new species (Turbinidae) Nerita fortidentala Wrmeij and Collins, new species (Neritidae) Alvania colombiana Romer and Moore, new species (Rissoidae) Faiartia (Murexiella) shaskyi DAttilio and Myers, new species (Muricidae) Metula crosnieri Bouchet, new species (Buccinidae) Metula africana Bouchet, new species (Buccinidae) Latirus martini Sn\der, new species (Fasciolariidae) Vasum Stephana Emerson and Sage, new species (Turbinellidae) Axi'lella Petit new name (Cancellariidae) Terebra imitatrix Auffenberg and Lee, new species (Terebridae) Hypselostoma holimanae Thompson and Lee, new species (Pupillidae) CEPHALOPODA Eledone gaucha Haimovici, new species (Octopodidae) 89 100 102 131 106 150 151 54 36 130 154 78 82 rHE NAUTILUS Volume 102, Number 1 February 16, 1988 ISSN 0028-1344 A quarterly devoted to malacology. Marine Biological Laboratory LIBRARY FEB 2 4 1988 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 Maiacoiogists, Inc. P.O. Bo.x 2255 Melbourne, FL 32902 CONSULTING EDITORS Dr William K. Emerson Department of Living Invertebrates The American Museum of Natural Historv New York, NY 10024 Mr. Samuel L. H. Fuller 1053 Mapleton .Avenue Suffiekl. 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 I'niversity Cambridge MA 02138 Dr. Aurele La Rocque Department of Geology The Ohio State L'niversitv Columbus, OH 43210 Dr. James H. McLean Department of Malacology Los Angeles County Musetim of Natural History 900 E.xposition 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 Geologv 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 P"lorida .Atlantic L'niversitv I?6ca Raton,' "Fl' 33431 Dr. G. Alan Soleiri Department of Invertebrates Field Museurri o£ Natural Historv Chicago, IL 60605 Dr. David H. Stansber\ Museum of Zoology The Ohio State Universitv Columbus, OH 43210 Dr. Ruth D Turner Department of Mollusks Museum of Comparative Zoolog\ Harvard Universit\ Cambridge, MA 02138 Dr. Geerat J. V'ermeij Department of Biology University of Mar\ land College Park, MD 20740 Dr. Gilbert L. Voss Division of Biology and Living Resources Rosenstiel School of Marine and Atmospheric Science Universit) of Miami 4600 Rickenbacker Causewav Miami, FL 33149 SUBSCRIPTION INFORMATION The suKscription rate per volimie is US $20.00 for individuals and US $30.00 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 pavment and sent to: THE NAUTILUS, P.O. Box 3430, Silver Spring, MD 20901. Change of address: Please inform the publisher of \our 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 THEt^NAUTILUS CONTENTS Volume 102, Number I February 16, 1988 ISSN 0028-1344 Rudiger Bieler Paula \1. \likkelsen Aiiatoni) and reproductive biology of two western Atlantic species of N'itrinellidae, with a case of protandrous hermaphroditism in the Rissoacea Helen DuShane Geographical distribution of some Epitoniidae (Mollusca: Gastropoda) associated with fungiid corals 30 \^ illiam K. Emerson Salter E. Sage, HI A new species of Vastim (Gastropoda: Turbinellidae) from off Somalia 36 Kurt Auffenberg Troy Auffenberg Density, spatial distribution, activity patterns, and biomass of the land snail, Geophoriis bothropoma Moellendorff (Prosobranchia: Helicinidae) 40 Notice 46 Marine Biological Laboratory LIBRARY FEB 24 1988 Woods Hole, Mass. THE NAUTILUS 102(l):l-29, 1988 Page 1 Anatomy and Reproductive Biology of Two Western Atlantic Species of Vitrinellidae, With a Case of Protandrous Hermaphroditism in the Rissoacea Kiidiger Bieler Smithsonian Marine Station at Link Port 5612 Old Dixie Highway Ft Pierce, FL 3-1946, USA Paula M. Mikkel^en Harbor Branch Oceanographic Institution 5600 Old Dixie Highway Ft. Pierce, FL 34946, USA ABSTRACT Two western Atlantic vitrinellids, Cyclostremiscus beauii (Fischer, 1857) and Circulus texanus (Moore, 1965) new com- bination are redescribed based on a study of live snails from the burrows of the stomatopod crustacean Lysiosquilla scabri- cauda (Lamarck, 1818). Anatoms and reproductive biology are emphasized, with the first recorded description of spawn and larval development in the famiK'. Synon\mies are given, and a lectotype is selected for Cy. beauii. Literature data concerning anatom) are reviewed for the marine near-planispiral risso- aceans; Vitrinellidae (including Cyclostremiscus and Circulus, with Circulidae as a synonym) is considered distinct from Tor- nidae. Unusual morphological aspects of Cy. beauii are dis- cussed, including external ciliation patterns, pallial tentacles (which are functionalK and morphologically different from each other), and stomach morpholog>' (with a large posterior chamber). Protandrous sequential hermaphroditism in Cy. beauii is inferred (for the first time in the Rissoacea) from morpho- logical evidence of sex change correlated with size. Key words: Cyclostremiscus; Circulus; Vitrinellidae; Torni- dae; Rissoacea; systematics; anatomy; hermaphroditism. INTRODUCTION Despite the great number of nominal species assigned to the poorK defined, cosmopolitan, marine rissoacean fam- ily \ itrinellidae Bush, 1897, little is known about the biology of its members. Their small size, mostly unknown habitats, poor representation in collections, and frequent confusion with other small-shelled members of groups such as Cyclostrematidae Fischer, 1885, Skeneidae Thiele, 1929, Turbinidae Rafinesque, 1815, and Tornidae Sacco. 1896, may account for the lack of attention paid to this family, and why authors who have attempted revisions (e.g., Trvon, 1888; Bush, 1897; Melvill, 1906; Pilsbry & Olsson, 1945; Pilsbry & McGinty, 1945a,b, 1946a,b, 1950; Laseron, 1958; Moore, 1964; Adam & Knudsen, 1969) relied almost entireK' on shell characters to distinguish ta.xa on all taxonomic levels. Aside from Pilsbry and McGinty 's (1945a, 1946b) sketches of crawling animals of several nominal genera. and studies on the gross morphology of Cochliolepis parasitica Stimpson, 1858 (by Moore, 1972) and C. albicerata Ponder, 1966 (by Ponder, 1966), published information on anatomy is available for only one species of this family, Circulus striatus (Philippi, 1836) from the eastern Atlantic. Data on Ci. striatus, extensively presented by Fretter (1956) and later summarized by Fretterand Graham (1962, 1978), were based on material which Fretter and Graham (1978:228) described as "the only live specimens . . . obtained by Fretter (1956) from the stomach of the starfish Astropecten . . . dredged on sandy bottoms 28-30 m deep in the Gulf of Gascony." Thus, the present concept of vitrinellid anatomv' is based mainly on Fretter 's description of a single species, Circulus striatus, the tvpe species of the name-bearing genus of the nominal family Circulidae (see Discussion, below). Discussions of phylogenetic relationships (or s\n- onymies) between families such as Vitrinellidae and Tor- nidae have demonstrated the need for anatomical and reproductive data for these groups (e.g., Fretter, 1956; Tavlor & Sohl, 1962; Moore, 1965; Golikov & Starobo- gatov, 1975; Boss, 1982; Graham, 1982; Ponder, in press). Studies on two species of western Atlantic N'itrinellidae are reported herein. Populations of Cyclostremiscus beauii (Fischer, 1857) and Circulus texanus (Moore, 1965) were discovered in Florida in sand-flat burrows of the stomatopod crustacean Lysiosquilla scabricauda (La- marck, 1818). These burrows are U-shaped and extend up to 1.5 m into the sediment, with horizontal distances of 6-7 m between the two openings; a pair of stomatopods inhabits each burrow system, maintaining it over long periods of time (Serene, 1954; R. B. Manning, personal communication). Cyclostremiscus beauii, with a shell diameter of 6-8 mm, is one of the largest vitrinellids, a fact that facilitated detailed studv of its morphology and anatomy and allowed a test of Fretter s hypothesis that some of the characters found in the much smaller (2 mm) Circulus striatus are size-related (Fretter, 1956:380). Special emphasis was placed upon characters of the reproductive svstem, for which Moore (1964:18) noted "Nothing is known of the reproduction of the famiK Page 2 THE NAUTILUS, Vol. 102, No. 1 except that the animals are dioecious, and that the male is provided with a penis." Data presented herein suggest that Cy. beauii is a protaiidrous sequential hermaphro- dite. Only incomplete data are available for Circulus texanus, as animals of this species were collected only twice, both times before the actual beginning of this study. However, since gross anatomy, spawn, and de- veloping eggs were observed for this species, available data are presented here. MATERIAL AND METHODS Samples were taken from stomatopod burrows in shal- low-water sand flats in the Indian River lagoon just inside the Ft. Pierce Inlet, St. Lucie County, eastern Florida (27°28.3'N, 80°17.9'W) using a stainless steel bait pump ("yabby pump") in conjunction with sieves of 1-2 mm mesh. Depths at low tide ranged from less than 0.5 m to supratidal, wherein the water level lay several centi- meters below the level of the sand. Living snails were maintained in Bnger bowls of sea- water at room temperature (24 °C). Carmine and fluo- rescein sodium particles were used to observe ciliary action and currents produced by the animals. For gross dissections, shells were cracked and animals subsequently relaxed using magnesium sulfate crystals ("epsom salts"). Other anaesthetic chemicals (7% magnesium chloride in distilled water, menthol crystals) were tried but pro- duced little or no effect with gradual addition, or too strong an effect resulting in retraction. Methylene-blue/ basic-fuchsin and neutral red were used to better delin- eate tissues and organs in gross dissections. Structures and organs were measured following in part the outline given by Davis and Carney (1973: fig. 4A). Terminology of the nervous system is after Davis et al. (1976). For histological sectioning, animals were relaxed as above and fixed in either glutaraldehyde-formalin so- lution (4% formalin, 2.5% glutaraldeh\de in 0.1 M phos- phate buffer, pH 7.2) or 5% buffered formalin (Humason, 1962:14). Shells were either broken and removed, or dis- solved in a 1% solution of ethylene diamine tetraacetic acid (EDTA, adjusted to pH 7.2). Specimens were embedded in paraffin, sectioned at 5-7 ^m and stained with Alcian Blue/ Periodic- Acid-Schiff (PAS), counter- stained with Harris' Hematoxylin/Eosin (Humason, 1962: 125, 269, 298). Staining reactions described in the text refer to this method unless otherwise rioted. Photomi- crographs of sections were taken with a Zeiss Photomi- croscope-3. Radulae and jaws were extracted by dissolving the surrouiitling soft tissue in a solution of lO'^ sodium hy- droxide. Spermatozoa were prepared for SEM by placing a drop of concentrated sperm in seawater onto a coverslip placed in a covered petri dish containing droplets of 25% glutaraldeliyde, and passing the coverslip through an etlianol series ending in acetone, and then critical-point drying the sample. Whole animals were fixed, passed through an ethanol series, transferred to amyl acetate, and critical-point dried. These, together with air-dried shells, radulae, jaws, and opercula were coated with gold/ palladium, and scanned using a Zeiss Novascan-30. Fig- ures 1-3 were photographed using a Hitachi S-570 scan- ning electron microscope. Radular terminology is after Bandel (1984:3). Protoconch and teleoconch diameters were recorded as the greatest dimension perpendicular to the columellar axis. Teleoconch height was the greatest dimension par- allel to the columellar axis, measured from the apex to the base of the aperture. Umbilical diameter was the greatest distance between the columellar lip and the most prominent portion of the umbilical wall, measured in ventral \ iew . Teleoconch w horls were counted from the protoconch Il-teleoconch line to the farthest extent of the periphery (= the point on the outer lip used for greatest shell diameter). The number of protoconch whorls was determined b\ the method of Ta\ lor (1975:10; sum- marized by Jablonski & Lutz, 1980:332, fig. 4). Cited repositories are (* indicates location of voucher material): ANSP — Academy of Natural Sciences of Philadelphia, PA. CAS — California Academy of Sciences, San Francisco. *IRCZM — Indian River Coastal Zone Museum, Harbor Branch Oceanographic Institution (HBOI), Ft. Pierce, FL. MCZ — Museum of Comparative Zoology, Harvard Uni- versity, Cambridge, M.A. MNHN — Museum National d'Histoire Naturelle, Paris. *RSMAS — Rosenstiel School of Marine and Atmospheric Sciences, University of Miami, 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. RESULTS Rissoacea Gray, 1847 = Truncateilacea Gray, 1840, "submission to be made to ICZN to suppress this name" (Ponder, 1985:15). Vitrinellidae Rush, 1897 Cyclostremiscus Pilsbry & Olsson, 1945:266. Type species: VitrineUa panamensis C B. Adams, 1852 (by original designation). Cyclostremiscus beauii (Fischer, 1857) (figures 1-52; tables 1, 2) Adeorbis Beauii Fischer, 1857a:173 [nomen nudum]. Adcorlns Reauii Fischer, 1857b:286, pi. 10, fig. 12 [Guade- loupe].—Bu.sh, 1897:104. Cyclostrema Beam [sic].— A. Adams, 1866:251, pi. 255, fig. 25 [after Fischer, 1857b]. Cyclostrema bicarinata Guppy, 1866:291, pi. 17, figs. 5a, b ["Miocene" (Lower Pliocene), Jamaica]. R. Bieler and P. M. Mikkelsen, 1988 Page 3 Skenea sulcata "Bush" Simpson, 1887:61 [nomen nudum, see Moore, 1964:131], Adeorlris Beaui.—DaW, 1889:150; 1892:345. Adeorbis Beam var bicarinata —DaW. 1903:1595 ["Oligo- cene," Jamaica]. "C.irculus" Incarinatus. — Woodring, 1928:439, pi. 37, figs. 10- 12 [neotype designation]. "Adeorhis" heaui. — Woodring, 1928:440. C.irculus stirophorus M. Smith, 1937:67, pi 6, figs. 2a, b [Pho- cene, Florida]. Cyclostrema angulata. — Hertlein & Strong, 1951:110 [West Indies]. Cyclostremiscus {Ponocyclus) heaui Incarinatus. — Pilsbry, 1953: 427, pi. 55, figs. 1-le. Vitrinella iSolariorbis) fceaui.— Abbott, 1954:138. Vitrinella beaui. — Wells et ai. 1961:267. Cyclostremiscus beaui. — Moore, 1964:131-135. — Morris, 1973: 138, pi. 40, fig. 19.— Porter, 1974:143.— Emerson & Ja- cobson, 1976:64, pi. 18, fig. 21 —Abbott & Dance, 1982: 58, text-fig. Cyclostremiscus {Ponocyclus) beaui. — Warmke & Abbott, 1961: 60, pi. 11, fig. b.— Humfrey. 1975:76, pi. 3, figs. U-lla. Cyclostremiscus (Ponocyclus) beauii. — Abbott, 1974:85, text- fig. 786.— Rios, 1975:38, pi. 10. fig. 131; 1985:41, pi. 16, fig. 177.— Yokes & Yokes, 1983:15, pi. 25, figs. 4-4a. Material examined: Lectotype (designated herein): 10.5 mm, MNHN unnumbered (Guadeloupe). Neotype of Cyclostrema bicarinata. 7.4 mm, USNM 115621 (Plio- cene, Jamaica); other material: 60 specimens: NORTH CAROLINA: 1 specimen with dried animal, BEVER- IDGE Sta. I (ex Astropecten). UNC-IMS. FLORIDA: Ft. Pierce Inlet: 10 March 1987, 1 male, 3 unsexed; 2-3 May 1987, 1 male; 24 June 1987, 3 males; 3 August 1987, 6 males; 31 August 1987, 7 females, 1 1 males; 1 4 September 1987, I female; 27 September 1987, 3 females, 2 males. Peanut Island, Lake Worth Inlet: 11 August 1987, 1 fe- male, 1 male. Boynton Beach: 1 shell, ANSP 277740. Miami: 1 shell, EOLIS Sta. 311, USNM 449192. Fowey Light: 2 shells, EOLIS Sta. 187, USNM 449193; 1 shell', EOLIS Sta. 129, USNM 449194; 1 shell, EOLIS Sta. 142, USNM 449195; 1 shell, EOLIS Sta. 170, USNM 449196; 1 shell, EOLIS Sta. 355, USNM 449198. Turtle Harbor: 2 shells, EOLIS Sta. 61, USNM 449197. Sand Key: 1 shell, EOLIS Sta. 162, USNM 449199. Kev West: 1 shell, EO- LIS Sta. 63, USNM 449200. Drv Tortugas: 1 shell, USNM 61114; 1 shell, USNM 271949. Cape San Bias; 1 shell, USBF Sta. 2402, USNM 323914. CARIBBEAN: St. Mar- tin; 1 shell, ANSP 20621. Jamaica: 1 shell, USNM 426872; 1 shell, USNM 442372. SOUTH AMERICA: CoveSas, Colombia: 1 shell, USNM 364409. Description Teleoconch (figures 1-3): Shell large for family [usu- ally 2-3 whorls, 6-8 mm diameter (x = 6.9, n = 56); height: X = 3.8, n = 33; umbilical diameter: x = 1.5, n = 30; largest specimen (female): diameter 11.5 mm, height 6.2 mm, umbilicus diameter 2.4 mm, teleoconch whorls 3%], nearly planispiral. Opaque-whitish, with 5-8 strong, concentric ribs on apical side, above peripheral keel. Widely-spaced irregular pustules between ribs (figures Table 1 . .Anatomical characters and character states, and hab- itat types of species in the vitrinellid-toriiid complex 1) Projecting snout bilobed, lateral extensions: (a) absent; (b) present. 2) Cilia along cephalic tentacles: (a) absent; (b) present 3) Terminal stiff setae on cephalic tentacles: (a) absent; (b) present. 4) Number of pallial tentacles. 5) Pallial tentacles: (a) all finger-shaped; {b) upper finger- shaped and lower paddle-shaped. 6) Upper pallial tentacle: (a) naked; (b) with motile cilia; (c) with stiff setae; (d) with distinct motile cilia and/or stiff setae. 7) Lower pallial tentacle: (a) naked; (b) with motile cilia; (c) with stiff setae; (d) with distinct motile cilia and/or stiff setae. 8) Gill filaments: (a) projecting from aperture in crawling position; (b) not projecting from aperture in crawling po- sition. 9) Anterior foot margin: (a) straight or only weakly indented; (b) cleft. 10) Posterior foot margin: (a) simple and rounded or weakly indented; (b) cleft. 11) Operculum nucleus: (a) concentric; (b) subcentral. 12) Number of whorls on operculum. 13) Eyes: (a) distinctly developed; (b) lack nerve supply. 14) Osphradium: (a) small, ciliated groove; (b) distinctly de- veloped, paralleling ctenidium. 15) Penis: (a) simple, without glandular processes, recurved; (b) with glandular area, directed straight back; (c) with several, finger-like processes. 16) Habitat: (a) under rocks; (b) under scales of annelid Poly- odontes lupina (Stimpson); (c) ? from stomach of starfish; (d) in burrows of stomatopod Lysiosquilla scabricauda (La- marck); (e) sandy mud bottom; (f) under large boulders on well-ox\genated sand\ mud. 5-8) on first whorl, becoming more dense and regularly spaced on second whorl. Fields of pustules on body whorl intersected by smaller concentric ridges, 4-6 between major ribs, added first between suture and first major rib, subsequently between peripheral ribs. Strong cords forming sharp peripheral and basal keels, separated by wide flat area, inclined ventrally and marked by growth lines, spiral cords, and pustules. Base widely umbilicate, with 0-5 concentric ribs between basal keel and umbi- licus; larger specimens showing decreasing number of ribs with increasing size. Umbilical wall often with 2-4 narrow ribs. Outer lip sinuous, with shallow sutural sinus. Microstructure (figure 4) of 3 layers: 2 thick cross-la- mellar layers and 1 thin homogenous outer layer thick- ened to form spiral ribs. Protoconch (figures 9-11): Diameter 0.40-0.48 mm (f = 0.45, n = 32). Protoconch I (prior to hatching) smooth, of about 1 whorl (diameter ~ 0.23 mm). Pro- toconch II (after hatching, before settling) of an addi- tional whorl, sculptured with irregular, more-or-less con- centric markings (figure 11). Total protoconch of 2 whorls, rather high-spired (spire angle = 50°). Page 4 THE NAUTILUS, Vol, 102, No. 1 Table 2. Summary of anatomical and habitat data for species in the vitrinellid-tornid complex. Characters and character states are listed in table 1. Sources of data listed under each species. ** = type species of genus; * = synonym of type S[)ecics of genus. *' = c according to VUmre. 1964:22; d according to Moore. 1964:159 W] biological data from Florida, except for Cochliolepis parasitica (also South Carolituil. Co. alhiccrata (-\e« Zfalaiid ' Cirrulus sirialiis (iucrnseN. English Channel Characters Species 12 3 4 5 6 8 9 10 11 12 13 14 15 16 Croup 1 **Vitrinella helicoidea C. B .\dunis, 1850 Pilsbry & McCinty, 194.5a: pi. 2, fig. 5; 1946b: 13. *Vitrinella praecox Pil.sbr\ & McGinty, 1946 Pilsbry & McGinty, 19'45a: pi. 2, fig. 4; 1946b:14. Teinostoma carinacallus Pilsbr\ & McGinty, 1946 Pilsbry & McGinty, 1946b:17, pi. 2, fig. 6b. Teinostoma lerema Piisbrv & McGintv, 1945 Pilsbry & McGintv, 194.5a:6, pi. 2, fig. la. Teinostoma parvicallum Piisbrv 6< McGint>, 1945 Pilsbry & McGinty, 194.5a:4. pi 2, fig. 2.' **Pleuromalaxis halcsi (Piisbrv & McGinty, 1945) Pilsbry & McGinty, 1945a: 10, pi. 2, fig. 8. **Cochliolepis parasitica Stirnpson, 1858 Stimpson, 1858:307ff.; Moore, 1972:100ff. Cochliolepis allncerata Ponder, 1966 Ponder, 1966.38, pi 5 *Circultts striatus (Philippi, 1836) Fretter, 1956:369ff ; Fretter & Graham, 1978:227£f. Circtilus texanus (Moore. 1965) This paper Cyclostremiscus beaitii (Fischer, 1857) This paper Cyclostremiscus pentagonus (Gabb, 1873) Bush, 1897:127, pi. 22, figs. 6, 12a-g [as Skenea trilix]. Group 2 **Tomura hicaudata (Piisbrv & McGintv, 1946) Pilsbry & McGinty, 1945a: pi. 2, fig.' 9; 1946b:15. *Parviturhoides interruptus (C. B. .\dams, 1850) Moore, 1962:695ff., fig. IB; 1964:21, 156ff.; 1972:106ff., figs. 5, 6. Group 3 **Tornus subcarinatus (Montagu, 1803) Woodward, 1898:140ff., pi. 8, figs. 1-3, 5-7; Fretter & Graham. 1978:229ff; Graham, 1982:144ff. a b a b a b a a a b a a a b b 2 b 2 b 2 1, 2 b 2 b 1 b 2 b 2 b 2 ? 9 adaaaa? ?a??a aadaaa? ?a??? adaaaa? ????a a^d'aa?? ????a addaaa? ????a adaaa?? ????a aabaaaa ?a?ab a — a — baaa 6a??a accbaaal2abac acbaaaa 8abad bcbaaaa 7abad ?????? o a o a 7 ? a b b 2 a b ? ? ? ? dbaba ?a?b bb2aaaaaab 'b External anatomy and organs of the mantle cavity (fig- ures 12- 18, 20-25, 27, 34-37): Living animal trans- lucent vellovvish-orange, with buccal mass, anteriormost gill tilaments, and tip of penis rose-pink; digestive gland brownish-orange. Base of ctenidial lamellae on osphra- (iial side pigmented white; central area of osphradium vvliitf Hanked bv brown lines on each side, resulting in pattern of parallel lines on left body side (figure 12). Long snout terminating in pair of muscular "lips," sep- arated by vertical slit with mouth opening. Lips sepa- rated Irom remainder ot snout bv strongiv ciliated groove. Serial sections revealed 2 narrow longitudinal bands of cilia, situated in grooves on each side, beginning shortly behind tip of snout. Two slender, De.xible, cephalic ten- tacles reaching appro.ximately twice length of snout when fullv extended. Left tentacle fitting into shallow notch formed bv ventral shell keel (figure 14). iMack eves on outer expanded bases of cephalic tentacles, each equipped with spherical, transparent lens. Ciephalic tentacles exhibiting elaborate pattern of mo- Figures 1-11. Cyclostremiscus heauii. specimens from Ft. Pierce Inlet, Florida (SEM) (figures 1-3, USNM 846323). 1. Shell, apical view (8.0 mm diameter). 2. Shell, umbilical view (5.0 mm diameter) 3. Shell, apertural view (4.1 mm diameter) 4. Microstructure of lateral body wall; fracture surface parallel to growing edge 5. Teleoconch sculpture, apical view. Circled numbers indicate location of sculptural details in figures 6-8. Stars indicate location of sutures. 6. Detail of teleoconch sculpture, first whorl. 7. Detail of teleoconch sculpture, second whorl. 8. Detail of teleoconch sculpture, third (= body) whorl. 9. Protoconch, apical view. ,\rro\v indicates sculptural line between protoconchs I and II. 10. Protoconch, lateral view. 11. Sculpture of protoconch I (left, smooth) and protoconch II (right, sculptured) Scale bars: 4, 5, 8-10 = 0.1 mm; 6, 7, 11 = 10 fim. R. Bieler and P. M. Mikkelsen, 1988 Page 5 11^ ^ %.. ^^^s ^^1^ X ^ V 1^- Page 6 THE NAUTILUS, Vol. 102, No. 1 R, Bieler and P. M. Mikkelsen, 1988 Page 7 lilc cilia and stiff bristles. Ventral tip of each tentacle with L-shaped, heaviK -ciliated groove surrounding smooth area, forming tactile pad (figure 25, tp). Nu- merous stiff bristles (lost during fixation, therefore not evident in histological or SEM preparations) distal to and just behind pad; additional bristles sparsely distributed over distal quarter of tentacle. T\\ o longitudinal ciliated tracts, situated in grooves, extending from region of pad on ventral side. Near tentacle base, innermost groove sloping dorsally toward dorsal midline; outermost groove ending proximal to expanded tentacle base (figure 20). [•fattened base of tentacle facing snout surface covered b\ additional, irregular, parallel tracts of cilia (figure 20). Third longitudinal ciliated groove on dorsal side of ten- tacle extending from flattened, triangular area just below eye to near tentacle tip (figure 18). Ciliated grooves usu- alK lined b\ narrow bands of brown pigment. Cilia fulK' retractable into grooves. C^ilia in grooves with distinct movement pattern (right tentacle: dorsal row — toward tentacle base, inner and outer ventral rows — toward tip; left tentacle: opposite directions). (These movements are easily mistaken for direction of ciliary beating, and there- fore current flow. However, further microscopic obser- vation with the aid of carmine and fluorescein sodium particles revealed lateral beating of the individual cilia across the tentacle, away from the snout, indicating that the apparent ciliary movement actualK reflects the con- duction of nervous impulses along the tentacle.) In cross- section, each tentacle usually with 3 nerves, 1 larger blood sinus, and several smaller blood spaces in central area, especially around nerve cords (figure 24). Foot (figures 12-14) elongate (just reaching posterior shell margin in crawling animal), flattened, densely and finely ciliated, with anterolaterally recurved corners; broadh rounded posteriorly and slightK indented at pos- terior terminus. Anterior pedal mucous gland (figure 14, amg) present, opening at center of transverse slit across anterior, leading edge of foot. No posterior mucous gland or metapodial tentacles. Locomotion by ciliary action. Operculum (figures 17, 34-37) corneous, circular, mul- tispiral, with about 7 whorls and small internal knob, supported by finely ciliated opercular lobes (figure 17, ol) on dorsal side of foot. Lobes simple, unpigmented, without tentacles. Lemon-shaped muscle scar on internal surface of operculum (figure 35). Mantle edge (figures 12, 13) somewhat scalloped, cor- responding to spiral ribs of shell. Large monopectinate ctenidium, attached along entire length to inner surface of mantle, originating on posterior left, curving over dorsum, terminating just above right eye where last few gill filaments protrude from aperture. Numerous (< 180) gill filaments (figures 16, 21) flattened, elongated leaflets, almost finger-like when contracted, forming tapered blades when extended. Filaments longest in central part of gill, decreasing somewhat in size toward both ends. "Supporting rods" lacking; filaments well supplied with blood spaces and muscles (transverse muscle bands giving extended filaments ladder-like appearance; figure 16). Both sides of blade carrying wide band of cilia off-center, closer to left (osphradial) side. Along right side in same relative position, each filament with longitudinal row of small embedded crystals (figure 16, cr). Narrow rim clear, somewhat thinner on "crystal" side, bearing continuous band of cilia. Filaments draining into large efferent bran- chial vessel leading to heart (figure 12). Filaments hardly reacted to direct physical stimuli, contracting rapidly when either cephalic tentacle or finger-shaped pallial tentacle (see below) touched. Whitish hypobranchial gland (figures 12, 13) paral- leling entire length of rectum, most conspicuous poste- riorly. Osphradium (figures 12, 22, 23) paralleling almost entire left side of gill, comprised of wide central area and two strongK developed, heavily ciliated, lateral zones. Central area w ith irregular chevron-like pattern of tracts of shorter cilia. Osphradial ganglion (figure 12, osg) very conspicuous at point about 'A of total length from mantle edge. Mantle cavity ending immediately behind poste- rior end of ctenidium. Two pallial tentacles (figures 13, 27) arising from just inside right mantle edge; upper (= most dorsal) tentacle finger-shaped, unciliated, somewhat closer to mantle edge, curling into shallow sutural sinus, directed dorsally. Low- er tentacle paddle-shaped, ciliated at edges (except on narrow stalk) and also across its broad surface; narrow band at tentacle edge unciliated. Single stiff bristles some- times occurring at tip. Lower tentacle originating at point on mantle edge ventral and slightly more interior to upper finger-shaped tentacle; directed anterolaterally. Stimulation with forceps or needle caused immediate contraction of upper tentacle (followed by contraction of cephalic tentacles and exposed ctenidial filaments). Lower tentacle showed little response to touch and can- not markedly contract (compare tentacles in figure 27). Lower tentacle observed to regulate and enhance water Figures 12-17. Cyclostremiscus beauii. 12. Male, left side, in crawling position (shell removed). Penis reflected anteriorly, out of mantle cavitv . 13. Female, right side, in crawling position (shell removed). Mantle slightly reflected to show relative insertion points of pallial tentacles. 14. Crawling animal, ventral view. 15. Diagrammatic cross-section through mantle cavitv of male, at level of osphradial ganglion. 16. Gill filament. 17. Diagrammatic view of closed operculum, as seen when animal is retracted, showing position of opercular lobes. Scale bars: 12-14 = 1.0 mm; 15 = 0.5 mm; 16 = 0 1 mm. ag, albumen gland; amg, anterior mucous gland; br, immobile bristles; cit, ciliary tract; com, columellar muscle; cont. connective tissue; cr, crvstals; ct, ctenidium; dg, digestive gland; ebv, efferent branchial vessel; es, esophagus; he, heart; hg, hypobranchial gland; in, intestine; ki, kidney; Ipt, lower pallial tentacle; mc, mantle cavity; me, mantle edge; ol, opercular lobe; op, operculum; OS, osphradium; osg, osphradial ganglion; ov, ovary; pe, penis; pvd, pallial vas deferens; re, rectum; sh, shell; sn, snout; st, stomach, ten, cephalic tentacle; upt, upper pallial tentacle. Page 8 THE NAUTILUS, Vol. 102, No. 1 H. Bieler and P. M. Mikkelsen, 1988 Page 9 tlow , by paddle positioning and by strong ciliary action, it'spccti\el\-, in or out of right side of mantle cavity. Alimentary system: Mouth opening between pair of muscular lips into large buccal mass (figure 42; length 1..') mm in specimen 8.5 mm shell diameter). Radula protrmling from short radular sac (figure 42, ras) ex- tending somewhat behind and to left of buccal mass. Paired jaws (figure 41) each crescent-shaped, appro.x- imately 0.5 x 0.16 mm (in specimen 7.8 mm shell di- ameter), composed of interlocking diamond-shaped ele- ments 14 /im in length. \ar\ ing slightK in shape across surface of jaw. Radula (figures 28-33) taenioglossate, with about 100 rows (max. 138; n = 7), length == 1.3 mm, width ~ 0.2 mm. Rachidian tooth (figure 31) wider than long (0.40 /im w ide. n = 8), with acute posterior corners projecting laterally, and concave front. Main cusp narrowly-trian- gular, unserrated, with 4-5 flanking cusps on each side (number of flanking cusps var\ing within single radula, apparently by splitting and fusion), decreasing laterally in size; base with 1 strong basal denticle per side, midway between posterior corners and central ridge. Lateral tooth ifigures 32, 33) with asymmetrical cutting edge, strongly indented at front edge, bearing large, narrowK -trian- gular, unserrated main cusp and highly variable number of flanking cusps (3-6 inner, 7-8 outer) decreasing in size laterally. Base of lateral tooth with broad central ridge; basal platform long, blade-like. Apex of inner mar- ginal (figures 30, 33) with short, stout main cusp, and 12-14 subequal, inner and outer flanking cusps. Stalk long, blade-like, with robust supporting ridge. Apex of outer marginal (figures 28, 30) with sharp, undulating inner margin (sometimes finely incised into closely-ad- hering flanking cusps), and smooth, rounded outer mar- gin. Esophagus opening widely into buccal cavity, without esophageal pouches. Salivary glands (figures 19, 26, 42) narrow, tube-like, empt\ ing into buccal mass at its lateral mid-point, extending posteriorly along esophagus. Posi- tion of salivar\ ducts relative to circumesophageal nerve ring highly variable: some or all passing through ring (n = 3; figure 49), stopping just anterior to ring (n = 4), or extending past without going through ring (n = 2). Relati\ e lengths of sali\ ary glands vary. Anterior part of esophagus, in cross-section (figures 26, 43), bearing 2 muscular, longitudinal, dorsal folds, their lower exten- sions coiling upwards to form .semi-isolated compart- ments, .interior esophagus thus divided into strongly cil- iated dorsal food channel (figure 26, dfc), larger ventral channel, and two small lateral pockets. Posterior to nerve ring (figure 42), ventral projections into main channel increasing gradualK in size, but without clear distinction between anterior and mid-esophageal regions. Food channel remaining dorsal. Dorsal folds and ventral pro- jections gradually decreasing in size, with posterior esophagus as a simple muscular tube. Stomach (figures 12, 38-40) amber in color, slightly translucent in li\'ing animal, approximately 4 x 1.5 mm (in largest specimen, 11.5 mm shell diameter), lying on exterior surface of visceral coil, appressed to the surface of digestive gland just posterior to heart and kidney, encompassing approximately Vi total length of digestive gland. Stomach consisting of two continuous chambers (figure 39) differing in function: anterior chamber ('/a of total stomach length) containing gastric shield, working end of cr\stalline style, and all openings into stomach; remaining -/3 forming large sorting and storage chamber. Esophagus entering stomach on left side at junction of anterior and posterior chambers. From this point, series of folds extending transversely across stomach, poste- riori) into posterior chamber, and anteriorU toward in- testinal opening. Opening to digestive gland lying to right of esophageal opening, between it and gastric shield. Gastric shield (figures 39, 40), with cup-like lateral wing upon which crystalline style rotates, protruding into an- terior chamber, and central longitudinal portion with flattened lateral expansion that cradles style, positioning it against cup-like grinding surface. Style sac and intestine, at anterior end of stomach, usualK partially obscured b\ connective tissue and kid- ney. Style sac (figure 39, ss) narrow, finger-shaped, ap- proximately '/3 length of stomach, not communicating directly with intestine [Johansson's (1940:1) group 3, re- vised after Mackintosh (1925)]. Style completely trans- parent, rod-shaped (length 1.8 mm, diameter 0.35 mm), rotating within style sac by action of denseK packed cilia on style sac walls, protruding into anterior chamber of stomach through flesh\ tube-like structure above gastric shield. Channel extending betw een digestive gland open- ing and intestinal opening at anterior terminus of anterior chamber. Figures 18-27. Cyclostremiscus beauii, specimens from Ft. Pierce Inlet. Florida (light micrographs or critical-point dried SEM preparations). 18. Head-foot (male), with mantle edge reflected posteriorly, dorsal view (SEM). 19. Sagittal section of male through buccal mass and esophageal region. 20. .\nterior view of snout and left cephalic tentacle, showing pattern of ciliated tracts on ventral surface (SEM). 21. Tip of gill filament ^SEMl. 22. Osphradium, anterior to osphradial ganglion (SEM). 23. Osphradium, cross-section through osphradial ganglion 24. Cephalic tentacle, cross-section. 25. X'entral tip of cephalic tentacle, showing tactile pad (SEM). 26. Esophagus, cross-section through anterior section, with salivary glands. 27. Pallial tentacles: upper, finger-shaped tentacle (retracted), and lower, paddle-shaped tentacle (SEM). Scale bars; 18 = 0.5 mm; 22 = 50 ^m; 19, 20, 23, 24, 26, 27 = 0.1 mm; 21, 25 = 20 ^m. bm, buccal mass; bs, blood space; car, cartilage; cit. ciliar\ tract; cont. connective tissue; df, dorsal folds of esophagus; dfc, dorsal food channel of esophagus; es, esophagus; leg, left cerebral ganglion; Ipt, lower pallial tentacle; me, mantle edge; ne, nerve; os, osphradium; osg. osphradial ganglion; pe, penis; ra, radula; rs, receptaculum seminis; sag, salivary gland; sn, snout; tp, tactile pad; upt, upper pallial tentacle. Page 10 THE NAUTILUS, Vol. 102, No. 1 R. Bieler and P. M. Mikkelsen, 1988 Page 11 Posterior chamber (figures 39, 47, pch) with irregular longitudinal folds along its left side leading from esoph- ageal opening, and well-defined longitudinal groove on its right side leading toward gastric shield. Central area \\ ith series of ciliated transverse folds. Proximal portion of intestine (figure 39, in) consisting of 3 histologicalK separate sections: (1) slightly bulging section immediately adjacent to stomach, containing large typlilosole, leading into second section via small loop; (2) very muscular, ball-shaped section passing un- der style sac to join third section; and (3) moderately ridged intestine proper, initially quite narrow, dilating slightly as it passes, without further loops or undulations, toward rectum in mantle cavity. Anus set back from mantle edge. No special ciliated tracts from anus to man- tle edge and exterior. Observed flow of particles {figure 39, smalt arrows): Large and small food particles enter stomach through esophagus. Counter-clockwise whirlpool at esophageal opening preliminariK' sorts particles according to size. Smaller particles pass laterally to right in groove toward gastric shield and style. Large particles move into pos- terior chamber along left series of longitudinal folds, passing to far posterior terminus of stomach. From there, particles pass into central area where peristaltic action manipulates and returns large particles to anterior cham- ber. ConcurrentK . smaller particles separate and/or break oft, and follow transverse folds toward right longitudinal groove, and then anteriorly within groove toward gastric shield. Large particles in central area of sorting chamber continue moving anteriorly to region of esophageal open- ing, where they pass rapidly by ciliary action directly to intestinal opening. Small particles entering area of gastric shield are manipulated by clockwise-rotating style against cup-shaped flange of gastric shield. Resultant particles move directly left into opening of digestive gland, guided by cuticularized lateral folds near style sac opening. Un- acceptable particles and material returning from diges- tive gland are shunted via longitudinal groove toward intestinal opening. Ball-shaped proximal section of in- testine probably serves as a pellet compressor. Live specimens fed on single-celled algae and detritus scraped from laboratory- aquaria walls. Fecal pellets oval, 0.33 X 0.19 mm (n = 5), round in cross-section, with rounded ends. Renopericardial system: Two-chambered heart and surrounding kidney visible on left surface of visceral coil, posterior to ctenidium and hypobranchial gland (figure 12). Kidney large, with nephridial gland on its outer wall. Kidney opening at posteriormost end of mantle cavity, without conspicuous ciliated tract associated with open- ing. No gonopericardial or renogonadial ducts observed. Nervous system: (iircumesophageal ganglia (figures 42, 43, 49) moderately concentrated. RPG ratio [Davis et ai, 1976:263; defined as length of pleurosupraesophageal connective/(length of connective + length of right pleu- ral ganglion + length of supraesophageal ganglion)] av- eraged 0.49 (n = 7). Cerebral ganglia connected by nar- row commissure, each separated from pleural ganglia by constriction. Tentacular nerves with distinct swellings at their bases. Pedal ganglia each with paired connectives, connecting anteriorly to cerebral ganglia, posteriorly to cerebropleural junctions. Pedal commissure very short, narrow. Subesophageal ganglion somewhat smaller than supraesophageal ganglion; connective to its pleural gan- glion much shorter. Statocysts (figure 44, stc) about 110 )xm diameter. Buccal ganglia small, conspicuous, joined by commissure passing beneath esophagus at posterior end of buccal mass. Highly-vacuoled connective tissue surrounding nerve ring, as well as other organs and areas throughout body. Reproductive system: .Animals in male phase (for dis- cussion of sex change, see below) distinguished from functional females by smaller size and by dark-orange, rather than creamy-orange or beige, gonadial coloration. Penis large (size at rest: length 2.5-3.0 mm, width at midlength 0.4 mm), muscular, somewhat flattened (fig- ures 12, 18, 42, 44) arising just behind and slightly right of bases of cephalic tentacles, coiling counter-clockwise back into mantle cavity. Fully extended penis may be longer than cephalic tentacles {e.g., 4.4 mm vs. 3.0 mm). Subcentral penial duct terminating in opening on slightly hooded tip, which, unlike remainder of penis, is uncil- iated. Long, closed pallial vas deferens extending from penis, along right side of body, to prostate in posterior part of mantle cavity (figure 44). Vas deferens relatively wide (diameter ~ 0.2 mm), tubular, forming prominent, somewhat undulating ridge that differs from surrounding tissue by its shiny, unciliated surface and by its white appearance caused by heavy internal ciliary action. Pros- tate orange, egg-shaped, 0.65-0.90 x 0.35-0.48 mm (n = 5), lying ventral to rectum, connected to right pallial vvall, its lumen communicating with mantle cavity by slit (~ 0.35 mm length) at its base (figures 44, 48). Vis- ceral vas deferens much narrower, passing through pos- terior mantle wall, leading along inner coil of visceral mass, where widened, extensively-coiled portion func- tions as vesicular seminalis (figure 47, vs) before reaching Figures 28-37. Cyclostremiscus beauii. radula and operculum, specimens from Ft. Pierce Inlet, Florida (SEM). 28. Outer marginal teeth. 29. Radula, whole mount 30. Inner marginal teeth. 31. Rachidian teeth. 32. Lateral teeth. 33. Tips of lateral (left) and inner marginal (right) teeth 34. Operculum, outer surface (2 1 mm diameter). 35. Operculum, inner surface (1.7 mm diameter). 36. Operculum, oblique lateral view of inner side (2 2 mm diameter). 37. Opercular peg, oblique lateral view. Scale bars: 28, 30- 33 = 10 Mm: 29, .37 = .50 fim. rac, rachidian teeth. Page 12 THE NAUTILUS, Vol. 102, No. 1 r\ipig ^^®9 stc sti pispec es PP9 mpg R. Bieler and P. M. Mikkelsen, 1988 Page 13 testis. Testis simple, elongated sac, yellow to bright or- ange, along inner right side of visceral coil, totalling 50- 60% of its length (figure 44). Spermatozoon (56-62 nm total length, n = 3) with slightly twisted head comprising elongated nucleus and pointed acrosome (~ 14% of total length), very long, narrow midpiece (« 58%) and long tail (* 28%). Atyp- ical sperm not found. Female reproductive tract (figures 13, 46) adjacent to rectum along right side of mantle cavity. Female open- ing, about level with anus, situated on muscular papilla hanging freel\ in mantle ca\it\ at distal end of capsule gland. From there, closed sperm duct leading posteriorly, initially forming very thick-walled muscular vagina (fig- ure 52), with lumen almost filled with large gland cells. Sperm duct giving rise to small, ball-shaped, dorsally- situated sperm pouch w ith weakK muscular walls. Thin- walled ducts leading from sperm pouch and muscular vagina joining shortly before opening into slit-like lumen of massive capsule gland. \'agina-t>pe muscular wall gradualK disappearing, while thin-walled part forms sperm channel ("sperm groo\e " in "ventral channel of authors), in communication with gland but partially sep- arated by lateral fold (figure 46, cross-section B, If). An- terior part of capsule gland w ith large, turquoise-staining gland cells; remaining capsule gland staining dark blue in sections. [M least in the anterior part, the gland cells are arranged in a comple.\ pattern (see Ponder, in press). A detailed histological description was hampered by the extremely strong staining reaction of the glands.] Pos- teriorly, glandular mass continuing, with communicating lumina, as albumen gland, .\lbumen gland massive, thick- walled, with narrow, slit-like lumen, pinkish-orange in living animals, staining turquoise in sections; folded as S-shaped loop on right side of animal, partK in parallel with posterior part of capsule gland. Posteriormost part of albumen gland pressing against, or, in large females, extending beyond posterior mantle wall. Sperm channel separating at junction of capsule and albumen glands, forming closed o\iduct. penetrating posterior mantle wall, and forming large, widened, non-glandular coil, con- taining (from sections and dissected specimens) both sperm and eggs. At its posterior end, coiled oviduct giving rise to 2 proximal sperm pouches, as inconspicuous, sub- equal, ball-shaped sacs, closeK' adjacent, and partialK' hidden under la\ers of connective tissue and kidnev. In ripe females, unoriented sperm, oltcn in large quan- tities, found throughout length of sperm channel and in anterior sperm pouch (functional bursa copulatrix). Packed oriented sperm, with heads embedded in walls, found in the two posterior pouches (receptacula seminis). Visceral oviduct very thin-walled, leading from coiled oviduct to ovary. Ovar\ situated at right side of visceral mass, structure not grape-like, extending over central 80% of digestive gland, covering half to all ot right side of coil (figure 46). (During copulation, sperm are apparently deposited in the \agina, temporariK stored in the bursa copulatrix and then stored in the two posterior receptacula. Fertil- ization occurs in the anterior part of the coiled oviduct, after which fertilized eggs pass through the ciliated lu- mina of the albumen and capsule glands where they are surrounded by capsular and mucous material. Eggs ap- parently enter the mantle cavity through the vagina, as no other female opening was found.) Sex and size relationships (figure 53): Specimens less than 7.6 mm shell diameter (n = 25) were all males. Specimens of shell diameter greater than 8.6 mm (n = 6) were all fully functional females without male repro- ductive structures. Specimens 7.8-8.5 mm shell diameter (n = 6) were "transitional" in appearance (figure 45); visceral and pallial reproductive organs were clearly fe- male, however, with visible remnant of pallial vas def- erens and "wound" (= penis scar) at attachment site of penis. Pallial vas deferens of smallest "transitional" spec- imen present as unciliated duct, partialK opened at prox- imal end, extending between penis scar and distal end of capsule gland. No positive connections observed. This specimen also with nearly transparent gonad containing small amount of whitish ovarian tissue in early part of coil, and with no sperm in the female system (it appar- ently had not yet mated in its female phase). Largest "transitional" specimen with fully-developed ovary, faint longitudinal marking on integument in position of vas deferens, and weak penis scar. Simultaneous possession of both ovarian and testicular tissues not observed. "Transition" somewhat correlated with date of col- lection (figure 53). Collections made between March and mid-August exclusively male. Fully developed females, "transitional" individuals, and males encountered in each of four collections in later part of August and September. Figures 38-43. Cyclostremiscus beauii. 38. Left lateral view of visceral coil, showing position of stomach. Dashed line indicates location of dorsal incision. 39. Stomach, dorsal view, opened at incision shown in figure .38. .\rrows inside stomach indicate flow^ of particles, 40. Gastric shield. 41. Right jaw, inner side, posterior end up. showing details of jaw elements. 42. Head with mid- dorsal incision show ing buccal mass, circumesophageal nerve ring, and base of penis. Connective tissue and minor nerves removed. 43. Central nervous s\stem, left side, oblique lateral view. Scale bars: 39, 42 = 0.5 mm; 41, 43 = 0.1 mm bg. buccal ganglion; bm, buccal mass; cpc, cerebropedal connective; cs, crystalline style; ct, ctenidium; dg, digestive gland; dgo, opening of digestive gland; es, esophagus; eso. opening of esophagus; gon, gonad; gs, gastric shield; in. intestine; ino. opening of intestine; ki. kidney; leg, left cerebral ganglion; Iplg. left pleural ganglion; Ipg. left pedal ganglion; mo, mouth; mpg. metapodial ganglion; on, optic nerve; os, osphradium; pch. posterior chamber; peb, base of penis; pipe, pleuropedal connective; plspec, pleurosupraesophageal connective; ppg, propodial ganglion; pvd, pallial vas deferens; ra, radula; ras, radular sac; rcg, right cerebral ganglion; rplg, right pleural ganglion; sag, salivary gland; sbeg, subesophageal ganglion; speg, supraesophageal ganglion; ss, style sac; st, stomach; stc, statocyst; stl, statolith; tns, swelling of tentacular nerve; ty, typhlosole. Page 14 THE NAUTILUS, Vol. 102, No. 1 spc'^ spc Figures 44-46. Cyclostremiscus beauii. reproductive system (semi-diagrammatic) 44. Male phase 45. "Transitional female phase. 46. Female phase, with three cross-sections (A, B, C) through female glands. Small arrows indicate reflected organs ag, albumen gland; an, anus; be. bursa copulatrix; eg, capsule gland; co, coiled oviduct; cont. connective tissue; ct, ctenidium; hg, hypobranchial gland, If. lateral fold, ov, ovary; pe, penis; pr, prostate gland; prom, opening of prostate gland into mantle cavity; R. Bieler and P. M. Mikkelsen, 1988 Page 15 Mating and larval development unknown. Protoconch morphology suggests planktonic veliger stage (see Dis- cussion). Sex change within single individual not ob- served. Habits and habitat: To our knowledge, this is the first record of habitat type for this species, i.e., within the burrows of thestoniatopod L(/sio.sq(n7/a scabricaiida, oth- er published records (,see synonym) ) refer only to empty shells. Wells et al. ( 1961 ) recorded Cyciostremiscus beatiii from the stomachs of Astropecten articutatus (Say, 1825), however it is unclear whether the material was alive when swallowed b> the starfish. Another specimen from gut contents of A. articutatus, in the UNC-IMS collec- tions, from 24 m depth off North Carolina, contained dried animal tissue and is the only other verified live- collected specimen known to the authors. Although bur- rows of other local species, e.g., callianassid shrimps, polychaetes, hemichordates, and sipunculans, were also sampled, these vitrinellids were not collected in associ- ation with an\- burrower but Lijsiosquilla during this stud\ . The snails probabK feed on algae, bacterial films and detritus in the burrows. They are capable of handling larger items in their alimentary tract, as evidenced by various shell pieces and foraminiferan shells found in the stomach. From the absence of glandular esophageal pouches and the presence of a crystalline style in the stomach, it can be inferred (Yonge, 1930) that free pro- teolytic enzymes, capable of digesting animal matter, are not present in this species and would not be expected in this group. Individuals were almost invariably collected in groups of more than one animal per burrow sample; the max- imum number encountered in one burrow sample was seven. Cyciostremiscus heauii was twice found crawling openly on sand or seagrass in the vicinity of Lysiosquilla burrow openings. In captivity, the animals were active crawlers and were not distracted by light; dark, sheltered areas in the tank (provided by black plastic film con- tainers) were not preferred. During resting periods, all specimens attached themselves to the wall of their con- tainer, just above the water level, by means of highly \ iscous mucus produced by the anterior pedal gland. This behavior was not correlated with food availability or water qualitv'. It might reflect tidal rhythm, but material was not sufficient to test that hypothesis. Geographical distribution: Western Atlantic, from North Carolina to Brazil (Ceara and Alagoas; teste Rios, 1985:41). Recorded from the Pliocene of Jamaica and Florida (see synonymy). Taxonomic remarks: Fischer (1857b;286), in the orig- inal description of Adeorbis heauii (in his earlier pub- lication, the name occurred only as a nude list name; 1857a;173), did not give an indication of the number of specimens in the original lot. Moore (1964T32) men- tioned a "holotype" in the Paris Museum. However, the single A. fceauii-specimen in that type collection (MNHN unnumbered, vidi) is much smaller than the dimensions given by Fischer (teleoconch diameter 6.3 mm, height 3.5 mm, protoconch diameter 0.42 mm, umbilical di- ameter 1.1 mm; protoconch whorls 2, teleoconch whorls 2%; vs. 10.5 mm maximum shell diameter in the original description). The specimen is therefore considered the only remaining syntype of a formerly larger lot, and is here selected as lectotype. Woodring (1928:440) pointed out the clo.se resem- blance between Guppy's (1866) Cyctostrerna bicarinata and Adeorbis beauii Fischer, but separated the two be- cause the latter "has a more strongly sculptured base." Smith (1937:67) in turn separated his new species CAr- culus stirophorus from both "Circuhis bicarinatus Gup- py" and "Circuhis beauii Fischer, ' by differing numbers of upper and basal spiral ribs. A re-examination of the neotype (Woodring, 1928) of Cyclostrema bicarinata (USNM 115621) and the original description and figure of Circuhis stirophorus Smith revealed that both fall within the range of variation (partly caused by ontoge- netic change of basal sculpture) displayed by the Ft. Pierce population, and both are here synonymized (see also Moore, 1964:131). The holotype of Circuhis stiro- phorus could not be located. Although the original author indicated the type to be in the MCZ collection, it was never received by that institution (K. J. Boss, personal communication); it was also not located at the Florida State Museum, Gainesville (F. G. Thompson, personal communication). Cyciostremiscus beauii is the largest vitrinellid in the western Atlantic. Two Recent Panamic species are very similar in size, shape and sculpture: Cyciostremiscus major Olsson & Smith (1951:46, pi. 3, figs. la,b) from Panama differs from Cy. beauii in having more numerous spiral ribs throughout and a more rounded periphery (holotype ANSP 187199; figured by Olsson & Smith, 1951). Cyclostrema gordana Hertlein & Strong (1951:110, pi. 9, figs. 3, 4, 7; holotype CAS 064803, vidi) from the Gulf of California, differs conchologically from Cycio- stremiscus beauii in having a prominent double spiral rib on the base between the basal keel and the umbilicus (see Pilsbry, 1953: pi. 55). Hertlein and Strong (1951: 110) gave the following measurements for the "unique type": maximum diameter 9.7 mm, minimum diameter 7.0 mm, and height 3.3 mm; our examination of the holotype yielded, respectively, 8.6, 6.8, and 3.9 mm. Hertlein and Strong (1951:110) compared C. gordana to "Cyclostrema angulata A. Adams [1850] from the West Indies ' [following "Pilsbry" (= error for Tryon), 1888: ps, penis scar; pvd, pallia! vas deferens; pw, posterior pallial wall; re, rectum; rs, receptaculum seminis; sc, sperm channel; spc, sperm channel; te. testis; va, vagina; vo, visceral oviduct; vs, part of visceral vas deferens serving as vesicula seminalis; vvd, visceral vas deferens. Page 16 THE NAUTILUS, Vol. 102, No. 1 Figures 47-52. Cycloslrcmiscus heauii, specinu-iis from Ft. Vwvcv Inlet, Florida (light micrographs or critical-point dried SEM preparations). 47. Cross-section through \isceral ma.ss (male), at level of ve.siciila seminalis. 48. Section through prostate, showing R. Bieler and P. M. Mikkelsen, 1988 Page 17 TW4-1 3- n D o D D o o o o o n15 10 5i 2 3 4 5 6 7 8 9 10 11 12 Imml Figure 53. Cyclostremiscus beauii. Plot of maximum shell diameter vs. number of teleoconch whorls (TW). Inset: Histogram summarizing sex distribution of collections, Ft. Pierce Inlet population. A = collecting period March-July, B = August 1-15, C = August 16-31, D = September, 1987. Open circles = empty shells and unsexed specimens. Open squares = functional males. Cross- hatched open squares = "transitional" females with pallial vas deferens and/or penis scar. Solid squares = females without male structures. Star indicates lectot>pe specimen (MNHN unnumbered). 92, they considered C. angulata a senior synonym of Cijclostremiscus beauii — see below] and stated that it differed "principally in the smaller size and more de- pressed form." However, a re-examination of the C. gor- dana t%pe showed it to differ principaJK- b\' a strong, second basal keel surrounding the umbilicus. It definitely belongs in the genus Cyclostremiscus, as advocated by Keen (1971), Tryon (1888), followed by Hertlein and Strong (1951), considered Cyclostremiscus beauii a synonym of Cy- clostrema angulata A. Adams, 1850: "C. angulata, A. Ad. was described as from the Philippines on the au- thority of Cuming, but as that great collector sometimes made mistakes, the localit> needs confirmation. There can be no doubt of the identity with this species of C. Beaui, Fischer (fig. 63), a West Indian species" (Tryon, 1888:92-93). Tryon 's figures (1888: pi. 32, figs. 64, 65) may represent Cyclostremiscus beauii. However, as sim- ilar species are known from the Indo-Pacific, we feel that the two nominal species should not be synony mized with- out a re-examination of Cyclostrema angulata type ma- terial, which could not be located in the British Museum (Natural History) (London) nor in the Redpath Museum (Montreal). The type species of Cyclostremiscus, Vitrinella pan- amensis C. B. Adams, 1852, and several other, similar species (see, e.g., Pilsbry & Olsson, 1945) have distinct axial sculpture which is lacking in Cy. beauii, Cy. major, Cy. gordana, and a number of other nominal species. Pilsbry (1953) described the subgenus Ponocyclus in Cy- lumen and opening into mantle cavity. 49. Section through circumesophageal nerve ring, with saUvary glands. 50. Spermatozoon (SEM). Arrow indicates junction of niidpiece and tail. 51. Same, detail of two heads (SEM). Arrow indicates junction between head and midpiece. 52. Cross-section through vagina (left) and rectum (right). Scale bars: 47-49, 52 = 0.1 mm; 50 = 4 ^m; 51 = 2 ^m. cc, cerebral commissure; cont, connective tissue; ope, cerebropedal connective; dg, digestive gland; es, esophagus; hg, hypobranchial gland; leg, left cerebral ganglion; Ipg, left pedal ganglion; mc, mantle cavity; mw, mantle wall; pc, pedal commissure; pch, posterior chamber of stomach; pr, prostate gland; prom, opening of prostate gland into mantle cavity; rcg, right cerebral ganglion; re, rectum; rpg, right pedal ganglion; sag, salivary gland; te, testis; tm, transverse muscle band; va, vagina; vs, part of visceral vas deferens serving as vesicula seminalis; vvd, visceral vas deferens. Page 18 THE NAUTILUS, Vol. 102, No. 1 R. Bieler and P. M. Mikkelsen, 1988 Page 19 clostremiscus \\ itli Adeorbis beauii as the type species, and distinguished it from Cyclostreniiscu.s by its lack of axial sculpture. As Pilsbr\ alread\ pointed out in his description of Ponocijclus (1953:426). there are a number of species showing intermediate conditions ("weak traces of axial sculpture") and the name is not used here. Due to the small number of species studied in the \ itrinellidae, little can he said about anatomical char- acters on the generic level. Aside from the large and elaborately-sculptured shell, the extensive ciliation of the head-foot, and the paddle-shaped pallial tentacle, Cy- clostremiscus beauii differs anatomically from Circulus striatus (see Fretter, 1956), Ci. texaniis (see below), and Cochliolepis parasitica (see Moore, 1972) in ha\ing the pallial portion of the intestine straight and uncoiled. Circulus Jeffreys, 1865 (page 315) Type species by monotypy: Delphinula duminiji Re- quien. 1848 (page 64; not "Trochus duminyi Requien" as usually cited) [= Yalvata? striata Philippi. 1836; see Jeffre\s, 1865:317, where he used the junior synon> m D. duminyi only to a\oid secondary homonymy with Tro- chus striatus Linne, 1767]. Circulus texanus (Moore, 1965) new combination (figures 54-68; tables 1, 2) Vitrinella texana Moore, 1964:66 [unpublished dissertation). Vitrinella texana Moore, 1965:76, pi. 7. figs. 4-6 [Gulf of Mexico]. ? Vitrinella texana "Moore, 1964" — .■Andrews, 1971:73-74, text- fig. — Andrews, 1977:887 [citing "1965"], text-fig. [poor fig- ure; = Vitrinella sp., teste Ode, 1987.35]. Vitrinella (Vitrinella) feiana,— Abbott, 1974:83. Vitridomus texana. — Ode, 1987:37. Material examined: Ho]ot\pe: empt\ shell, 1.8 mm, USNM 636311 (Texas). Other material: 15 specimens. FLORIDA: Ft. Pierce Inlet: 2-3 May 1987, 1 unsexed; 24 June 1987, 14 specimens (4 males, 7 females, 2 un- sexed, 1 empty shell). Description Teleoconch (figures 54-56): Shell small (1.7-1.8 mm diameter, 0.55-0.65 mm height), with 1V2-1% teleoconch w horls; almost planispiral, sculptured dorsalK' and ven- trally with about 18 fine spiral ribs; transparent when alive, opaque after death. Ribs slightly stronger, more widely spaced just below suture on dorsum and at pe- riphery, where about 3 ribs form rounded keel below lateral midline. Suture impressed. Ventral surface below keel less convex, often with 30-40 widely-spaced, low axial ribs which are primarily evident from inside of body whorl (figure 57). L'mbilicus wide (~ 25% of width). Outer lip ver>- slightly reflected; some specimens with one former varix. Aperture at oblique angle to dorso- ventral axis. Sutural sinus shallow. Periostracum thin, transparent, with spiral grooves more numerous than on shell surface. Protoeonch (figure 58): Smooth, 0.5 mm diameter, about 2 whorls. No sculptural demarcation separating protoeonch I and protoeonch II. External anatomy and organs of the mantle cavity (fig- ures 64-66): Living animal translucent white with buccal mass (visible through proboscis) and protrusible portion of ctenidium rose-pink; digestive gland orange; ner\e ring area opaque yellow, visible through integu- ment between eyes. Head with long, extensible snout, rounded and terminally notched at mouth. Ventral side of snout ciliated behind mouth opening, with cilia beat- ing toward mouth. Two long cephalic tentacles w ith im- mobile bristles on slight]} enlarged tip; motile cilia at least at tip and along side facing snout. Left cephalic tentacle fitting into shallow notch formed by shell keel (figure 65). Eyes black, on slight bulges at base of cephalic tentacles. Neck region very long, slender. Foot elongate, flattened, with anterolaterally recurved corners; fineK ciliated sole broadly rounded posteriorly, extending well beyond shell (figure 65). Transverse crease on sole about '/^ of total length from anterior edge. Anterior pedal mucous gland (figure 65, amg) opening at slit across entire leading edge; mid- ventral fold evident on posterior quarter of sole, but presence of posterior mucous gland not confirmed. Locomotion by ci]iar\ action. Operculum (figures 61-63) corneous, circular, multispiral {ca. 8 whorls), with small central peg and rounded-triangular muscle scar on inner surface. Operculum supported by opercular lobes (figure 65, ol) on dorsal side of foot. Lobes simple, unpigmented, without tentacles. Epipodial ten- tacles absent. Two finger-shaped pallial tentacles (figure 64, Ipt, upt) arising separately but adjacently from inner mantle edge, at right side of animal. Upper (= most dorsal) tentacle unciliated, with immobile terminal bristles, curling into shallow sutural sinus, directed dorsalK during crawling. Lower tentacle bearing motile cilia, directed anterolat- erally. Ctenidium (figures 64, 65, ct) with numerous fin- ger-shaped filaments, attached for most of its length to internal surface of mantle; anteriormost filaments darker Figures 54-63. Circulus texanus, specimens from Ft. Pierce Inlet, Florida (SEM) (figures 54-56, USNM 846324). 54. Shell, apical view (2.7 mm diameter). 55. Shell, umbilical view (2.7 mm diameter). 56. Shell, apertural view (2.2 mm diameter). 57. Inside surface of base of bod> whorl, showing shallow radial grooves. 58. Protoeonch. 59. Larval shell, left lateral view (167 /im max. diameter! 60. Radula. 61. Operculum, inner surface (0.7 mm diameter) 62. Operculum, outer surface (0.8 mm diameter). 63. Operculum, oblique view of inner surface with opercular peg. Scale bars: 57, 58 = 0.2 mm: 60 = 5 ^m; 63 = 50 ^m. rac, rachidian teeth. Page 20 THE NAUTILUS, Vol. 102, No. 1 Figures 64-68. Circulus texanus. 64. Crawling female, dorsal view, drawn as with transparent shell. 65. Crawling animal, ventral view, drawn as with transparent shell. 66. Head of male, left lateral view, showing penis. 67. Egg mass 68. Two egg capsules, each with veliger larva shortly before hatching. Scale bars: 64, 65 = 0.5 mm; 66, 67 = 0.25 mm. ag, albumen gland; amg, anterior mucous gland; br, immobile bristles; eg, capsule gland; ct, ctenidium; dg. digestive gland, ebv, efferent branchial vessel; ey, eye; he, heart; in, intestine; ki, kidney; Ipt, lower pallial tentacle; ol, opercular lobe; op, operculum; ov, ovary; pe, penis; re. rectum; sh, shell; sn, snout; ss, style sac; st. stomach; ten, cephalic tentacle; umb, umbilicus; upt, upper pallial tentacle. in color, not attaclu'd to tnantle skirt, extending out ot aperture at right side of head. E.xtent of osphradium not ascertained. Alimentary system: Riiduia (figure 60) taenioglossate. Rachidian tooth wider than long, with acute posterior corners projecting laterally and concave front. Main cusp narrow, unserrated, with 5-6 slightly smaller flanking cusps on each side (number of flanking cusps var\ ing within single radular rihhon) decreasing laterally in size; base with 1 weak elevation per side (in position of basal denticle), midway between posterior corners and central ridge. Lateral tooth with asymmetrical cutting edge, strongly indented at front edge, with narrow , unserrated main cusp and subequal flanking cusps (6-7 inner, 9 outer). Apex of inner marginal tooth with numerous long, thin, flanking cusps on either side of similarly-sized main cusp. Apex of outer marginal tooth with long, thin inner flanking cusps, slightly more robust than tho.se of inner marginal tooth; cusps at termiiuis subequal in size; outer margin with 2-3 cusps decreasing in size, remainder of outer margin smoothly rounded. Jaws composed of ele- ments approximately 4 ^m in length. Stomach traii.spinciit, with rotating style often clearly visible through shell. Posterior part of stomach not mark- edly elongated. Intestine (figures 64, 65, in) forming wide loop in posterior part of mantle cavity. Anus just above anterior end ol capsule gland in females. Fecal material R. Bieler and P. M. Mikkelsen, 1988 Page 21 as continuous rods of irregular length, rather than pellets, with no obvious surface sculpture. Reproductive system: Penis ifigure 66, pe) a posteriorly directed, counterclockw ise, double coil; base arising pos- terior to eyes, somew hat right of dorsal midline. Testis orange. Ovary (figure 64, ov) filling inner side of early whorls with grape-like lobes, lighter in color than digestive gland. Capsule gland and much darker-staining (in metln lene blue) albumen gland (figure 64, eg, ag) forming compact mass on right wall of mantle cavity, below rectum, ter- minating anteriorly at level of anus. Position and number of sperm pouches not ascertained. No evidence of se.xual dimorphism associated with possible sequential hermaphroditism. Males both consid- erably smaller (1.7 mm diameter at 1% whorls) or larger (1.8 mm diameter at 1': whorls) than females in same sample (1. 74-1. 78 mm at I'/s whorls). One copulation briefly observed, wherein male paused while crawling over dorsal surface of female, with heads adjacent (male at left) and at angle of about 30°. Position of penis not ascertained. Eggs and larval development: Three weeks after col- lecting, 7 females and 4 males were placed into glass bowl with seawater (24 °C). Overnight, 15 egg masses were laid; each mass contained 1-5 eggs, each in clear, flattened, circular capsule (egg diameter 1 10 fim: capsule diameter 170 ^m; n = 20). All eggs found in same de- velopmental stage, uncleaved, completely round, finely granular. Soft capsule walls of eggs laid in groups touch- ing each other; each "mass," even if consisting of single egg, coated b\ sticky, clear, gelatinous layer (figure 67). Eighteen additional egg masses were found in glass jar in which specimens had been kept since collecting. Total number of masses (with respective numbers of single- egg-capsules) was: 4 masses with 1 capsule, 4 masses with 2, 13 masses with 3, 9 masses with 4, and 3 masses with 5 capsules. One mass with 5 eggs followed through development: From beginning of equal, holoblastic 2-celled stage, 60 minutes elapsed to 4-celled stage, 205 minutes to 8-celled stage, 385 minutes to 16-celled stage, respectively. Gas- trula-stage discernible after 1 1 hours; embryos rotating after 17 hours. X'eliger larvae (figure 68) fully developed at 104 hours, intermittently or constantly rotating, with transparent shell, 2 short veliger lobes, black eye spots (not situated on tentacles at this point), statocysts and operculum [much as described for Caecum glabrum by Gotze (1938:108, text-fig. 33), but with smaller vela]. Periphery of velar lobes bearing long cilia, underlain by row of shorter cilia. Capsule size now approximately 150 x 120 fim, greatest shell diameter 107 /xm, longest dimension of veliger with extended \ela 133 ^m. During entire process, 3 of 5 embryos developed completely synchronously; other 2 initially about 45 minutes, later several hours, behind. First veligers hatched after 130 hours and swam actively. For follow ing 36 hours, veligers observed either swim- ming or resting on bottom of bowl, with strong ciliary action on extended vela. No further development noted. Added cultures of mixed single-celled green algae ap- parently not excepted; all larvae died within next 2 days. [From the size difterence between these larvae (170 nm) and the protoconchs of adult shells (500 nm), a longer lar\al stage, w ith extensive food intake can be predicted.] Habits and habitat: Habitat as described for Cyclo- stremiscu.s hcaiiii. In the laboratory, animals of Circiilns texanus were very active and fed on normally-occurring algal and bacterial surface films. Geographical distribution: Circuhis texanus (type lo- cality: Mustang Island, near Port Aransas) was previously reported to be endemic to the northv\estern Gulf of Mex- ico, and has never been reported alive (Moore, 1964:41; .\ndrews, 1977:87; Ode, 1987:37). No fossil records are know n. Taxonomic remarks: Moore (1965:77) placed this species in the genus Vitrinclla C. B. Adams, 1850, and pointed out the differences in shell shape and sculpture in com- parison to other species. However, members of Vithnella (based on the type species V. helicoidea C. B. Adams, 1850; see tables 1, 2) are generally smooth-shelled or weakly sculptured and are usually furnished with a ca- rina bordering the umbilicus (e.g.. Keen. 1971:377; Ab- bott, 1974:82). We feel that this species is better placed in Circuhis sensu lato because it agrees in shell shape and sculpture with the type species, Circuhis striatus from the eastern Atlantic. Ode's (1987:37) placement of this species in VHridomus Pilsbry & Olsson, 1945, cannot be accepted: members of Vitridomus [a "rather feebly defined genus (Pilsbry & Olsson, 1952:36), very similar to Teinostoma H. & A. Adams, 1853] ha\ e the umbilicus partly covered by a callus. DISCUSSION Comparison of the anatomical information on Cyclo- stremiscus beauii and Circuhis texanus with literature data revealed that published information is scarce or misleading, and that genus- as well as family-level taxa of marine near-planispiral Rissoacea are poorly defined. Three nominal families, Vitrinellidae Bush, 1897, Tor- nidae Sacco, 1896, and Circulidae (for authorship, see below), are currently in use for members of this group, and the lack of comparative data led Ponder (in press) to treat all three families as a single group in a phylo- genetic analysis of the Rissoacea. In the follow ing dis- cussion, we (a) review the available data on species of this complex, (b) compare Cy. beauii and Ci. texanus w ith these data and with other members of the Rissoacea, (c) suggest a preliminary grouping for the species for w hich anatomical data are available, (d) demonstrate the differences between Vitrinellidae and Tornidae, (e) eval- uate the taxonomic status of the nominal family Circu- lidae, and (f ) discuss some unusual aspects of the anatomy and reproductive biology of Cy. beauii. namely ciliation. Page 22 THE NAUTILUS, Vol. 102, No. 1 tentacle shape, stomach morphology, and hermaphro- ditism. (a) Available literature data (see tables I, 2). Except for Fretter's (1956) study of Circulus striatus, and Woodward's (189S) and Graham's (1982) work on Tornus suhcarinatus, most of the available data on the anatom\ of marine near-planispiral Rissoacea are re- stricted to descriptions or illustrations of external mor- phology, especially Pilsbr\ and McGinty's (1945a, 1946b) sketches of western .\tlantic forms. Some of the few published observations on the radular structure and gross morphology of vitrinellid softbodies are misleading (see also Moore, 1964, 1972). Based on the misconception that these species are archaeogastropods. Rush (1897:127, 142, pi. 22, figs. 12a-g) erroneously constructed a rhipido- glossate radula for Circulus trilix (Bush, 1885) [= Cy- clostremiscus pentagonus (Gahh, \8S7), fide Moore, 1964; 138]. The "supplementar\ plicated gill" (Stimpson, 1858: 308) of Cochliolepis parasitica uas not found in that species by Moore (1972:101). Pilsbry (1953:427) men- tioned a taenioglossate radula for Cyclostremiscus beauii, and added "This will be figured in a paper now in prep- aration b\ T.L. McGinty and the author " This work was apparentl) never published. (b) Comparison of Cyclostremiscus beauii and Circulus texanus with other \itrinellids and rissoaceans. Both Cyclostremiscus beauii and Circulus texanus dis- play "typical" rissoacean characters (as outlined by Fret- ter & Graham, 1978:153; Boss, 1982:984; Ponder, 1983, in press) and agree to a large extent with the previous concept of Vitrinellidae (Fretter, 1956; Moore, 1972; see tables 1, 2, Group 1). As in most other vitrinellid species, the cephalic and pallial tentacles bear immobile bristles and/or motile cilia. Tracts of motile cilia on the cephalic tentacles occur in numerous groups in the Rissoacea; for lack of comparative data, it is not yet clear whether the arrangement of these cilia in grooves, as in Cy. beauii, is unusual. Photographs of critical-point dried tentacles of a freshwater rissoacean, the hydrobiid Tryonia ctath- rata Stimpson, 1865 (see Hershler & Thompson, 1987: 27, figs. 13-17), show no grooves present in that species. Cyclostremiscus beauii and Circulus texanus have two closely-spaced pallia! tentacles on the right side. This arrangement is present in most studied vitrinellids (the exception being Cochliolepis albiceratus Ponder, 1966), in the type species of Tornus (Tornidae, see below), in Hydrococcus brazieri (T. Woods, 1876) (monotypic Hy- drococcidae, see Ponder, 1982), and in the rissoid genus Rissoina Orbigny, 1840, where some species have either the anterior (right) or posterior (left) pallial tentacle bi- lobed (Ponder, 1985:78). As described for Cy. beauii, the function of the upper tentacle, which usually bears im- mobile bristles, and is held upright and bent around the aperture, is clearly sensory, while the lower one, often distinctly ciliated and sometimes broadened, controls and/ or enhances water flow. Both species have a small central opercular peg which is probably not homologous with the lateral "neritid- type " peg in other families of Rissoacea (character con- sidered plesiomorphic in this superfamily), while the cir- cular shape of the vitrinellid operculum is considered derived (Ponder, 1985:5). The osphradium of Cyclostremiscus beauii is ver) sim- ilar to those described for Circulus striatus (see Fretter, 1956:372) and for species of the Rissoidae (Johansson, 1939:319, pi. 3, figs. 3, 4, text-fig. 5; Haszprunar. 1985: 476, figs. 7k, 16). The radulae of the two species studied here ha\ e only one pair of basal denticles (or elevations) on the rachidian tooth, a feature known from some other rissoacean fam- ilies, such as Hydrobiidae (see Bandel, 1984:29, text-fig. 47) and Rissoidae (see Ponder, 1985:10). This character was hvpothesized to be primitive in the Rissoacea by Ponder (1985:119). The position of the salivary glands relative to the cir- cumcsophageal nerve ring is often used in family- and superfamiK -level discussions (e.g., Ponder, 1983:236, 258; in press). However, as a highly variable character in the populations of Cyclostremiscus beauii studied herein, further data on additional species are necessarv before it can be reliabl) utilized to infer phylogenetic relation- ships of the Vitrinellidae. The extensive anterior section of the esophagus of Cy- clostremiscus beauii, with its long, coiled, dorsal folds, is verv similar to that of Hydrococcus brazieri (see Pon- der, 1982:77). The conspicuous ciliated tract leading from the renal opening to the head of Circulus striatus (see Fretter, 1956:372) is lacking in Cyclostremiscus beauii. The presence of markedly vacuoled connective tissue in Cyclostremiscus beauii is a character shared by Cir- culus striatus and Tornus subcarinatus (see Graham, 1982:147). The nervous system of vitrinellid species is tvpically rissoacean and shows moderate (Cyclostremiscus beauii) to high (Circulus striatus; Fretter, 1956:377) concentra- tion. The RPG ratio of Cy. beauii, averaging 0.49. lies within the range of those of members of the rissoacean family Pomatiopsidae (see, e.g., Davis ii Mazurkiewicz, 1985:45, table 8). The structure of the male and female reproductive systems encountered during this stud\ is ris,soacean (e.g., Johansson, 1956). As in most other rissoaceans (e.g.. Pon- der, 1985:6), the albumen and capsule glands form a single, continuous mass [a character not recognizable from Fretter's (1956) description and figures of Circulus stria- tus]. The N'itrinellidae differ from the Rissoidae (e.g.. Ponder, 1985: text-fig. 2) wherein a non-homologous structure, an expanded part of the upper oviduct, pos- terior to the bursa copulatrix and/or receptacula seminis, functions as an albumen gland. This "upper oviduct gland " of the Rissoidae is homologous with the coiled part of the visceral oviducts of the Hvdrobiidae (see Johansson, 1956) and N'itrinellidae [Fretter's (1956) "ren- al oviduct ']. Most members of the Rissoacea have one bursa cop- ulatrix and one receptaculum seminis near the posterior R. Bieler and P. M. Mikkelsen, 1988 Page 23 pallial \\ all, ifquii iiig the sperm to travel the entire length of the sperm ehannel (vaginal lumen, sperm groove of the ventral channel of authors) immediately after cop- ulation. Others have develeoped additional, ilistal sperm pouches (anterior sperm-storage structure, distal l)lind sac, sac-hke vestibule, spermatheca, pseudo-bursa of au- thors), eitlier in addition to [e.g., Ptisillina incon.^pictia (Alder, 1844); see Johansson, 1939:337. text-fig. 22 (as Rissoa); Rissoidae], or instead of the pro.ximal bursa cop- ulatrix [e.g., Htjala vitrea (Montagu, 1803); see Johans- son, 1949: text-fig. 1; Iravadiidae]. These distal sperm pouches are not necessarily homologous with each other and certainly not with the proximal bursa (see, e.g., Sla- voshevskaya, 1978). Vitrinellids for which such data are available (CArciilus striatus and Cyclostremiscus beauii) differ from most other rissoaceans in the presence of two more-or-less eciually developed, proximal receptacula seminis which, in position and size, look much like the two sperm sacs {i.e., bursa copulatrix and receptaculum seminis) of other Rissoacea {e.g., in the rissoid Lucidestea Laseron, 1956; see Ponder, 1985:67, text-fig. 3). Whether the presence of two proximal receptacula seminis is a distinguishing character for Vitrinellidae cannot yet be determined, as accessory receptacula have been dem- onstrated for members of the genus Alvania in the Ris- soidae (Johansson, 1956; Ponder, 1985). In both Circiilus striatus (see Fretter, 1956:377) and Cyclostremiscus beauii, the distal end of the coiled oviduct serves as the fertilization area, and not as an additional functional receptaculum as has been reported for some other ris- soaceans [e.g., Alvania suhsoluta (Aradas, 1847), where the distal end contained oriented sperm; Johansson, 1956: 380]. The spawn mass of members of the Rissoidae usually has numerous eggs per capsule in planktonic forms, while one-egg-per-capsule is characteristic of "direct ' devel- opment (see Lebour, 1937; Thorson, 1946). This does not hold true for the spawn of Circiilus texanus, which gen- erally resembles that of the freshwater rissoacean Bithijn- ia tentaculata (Linne, 1758), as described and illustrated by Ankel (1936:164, text-fig. 142B). [The number of eggs there, however, is larger (4-24; Lilly, 1953:104), and hatching occurs at the crawling stage]. Jablonski and Lutz (1980:336; after Taylor, 1975) stated that the Rissoacea ". . . follow one of two developmental pathways: those that hatch as crawling juveniles from relatively large eggs (140-320 nm) and those that hatch from relatively small eggs (60-130 jxm) and spend 2-3 weeks as planktonic veligers. Both species studied here definitely fall into the latter category: veliger shells of Circulus texanus (figure 59) were one full whorl smaller than the final larval shells as seen in the adult protoconch (figure 58); the protoconch of Cyclostremiscus beauii (figures 9-11) shows a distinct line and change of sculpture between protoconch I and protoconch II, with almost another full whorl of growth before metamorphosis, suggesting sev- eral weeks (K. Bandel, personal communication) of planktonic life. In his unpublished revision of western Atlantic Vitrinellidae, Moore (1964:18) inferred that "most, if not all, species appear to have a planktonic veliger stage of some duration." The sperm cells of Cyclostremiscus beauii are of the general type known tor other members of Rissoacea (see Gotze, 1938; Franzen, 1955). The twisted acrosome and relative lengths of head, midpiece and tail are similar to those described by Franzen (1955) for Caecum glabrum (Montagu, 1803). The head is much shorter than that of the two rissoids previously studied [Pusillina incon.spicua (Alder, 1844) (as Rissoa) and Onuba striata (J. Adams, 1797); Franzen, 1955:406-409], and the relative length of the midpiece much greater than in Hydrolna ulvae (Pennant, 1777). Direct communication of the coiled ("renal") oviduct with the kidney (Fretter, 1956), previously considered unique for Circulus or the Vitrinellidae, is now also known for other families of the Rissoacea (Tornidae, Graham, 1982; Truncatellidae, Fretter & Graham, 1962). Anatomical characters of Circulus striatus, which Fretter (1956:380) discussed as probably "associated with small size and body form," are equally expressed in the much larger Cyclostremiscus beauii, suggesting that Fretter's hypothesis was incorrect. (c) Preliminary grouping of "vitrinellid-like" species for which anatomical data are available. The species for which sufficient gross morphological data are available appear to fall into three groups, two of which are here considered of familial rank and one comprising species of incertae sedis (tables 1, 2). Mem- bers of Group 1, currently placed in the genera Vitri- nella, Teinostoma, Pieurornalaxis, Cochliolepis, Circu- lus and Cyclostremiscus, are here considered to belong to the Vitrinellidae (the placement of the species de- scribed as Cochliolepis albicerata Ponder, 1966, is some- what doubtful as it has only one pallial tentacle, and the morphologies of its osphradium and penis are unknown). Some of the characters attributed to the family Vitri- nellidae in Moore's dissertation (1964) were based on Parviturboides interruptus (C. B. Adams, 1850) (tables 1, 2, Group 2), later considered a species of uncertain systematic position (Moore, 1972:107). This species dif- fers from the other forms here grouped in Vitrinellidae by the following anatomical characters: posterior foot margin with immobile cilia, left cephalic tentacle with four low swellings on proximal posterior border, penis with glandular area and directed straight back. Another species, Tomura bicaudata (Pilsbry & McGinty, 1946) differs in many head-foot characters (tables 1, 2, Group 2) and is here also considered as incertae sedis. White (1942:92) advocated the inclusion of "Cyclostrema" bushi Dautzenberg & Fischer, 1907, in the Vitrinellidae/Tor- nidae complex and published anatomical descriptions and illustrations of that species. While some morpho- logical characters [head with well-developed eyes and terminally ciliated cephalic tentacles, the well-developed osphradium (1942: text-fig. 6), and the circular, multi- spiral operculum (1942: pi. 2, fig. 3)] agree well with the species listed here as vitrinellids, the glandular pouches Page 24 THE NAUTILUS, Vol. 102, No. 1 in the esophagus and, most of all, the pair of epipodial (not pallial) tentacles on the right side of the animal (White, 1942:90, text-fig. 5), prevent inclusion in \itri- nellidae. Tornm siibcarinatus (tables 1, 2, Group 3) is here considered a member of a separate famiK (see be- low). (d) Family relationships: Vitrinellidae-Tornidae. Several attempts have been made to define the key characters of the family Vitrinellidae [e.g., Moore, 1965: 74, 1969:170, 1972:107ff.; Boss, 1982:991). However, be- cause of the small number of species fulK studied ana- tomicall), no single synapomorphy defining the famiK is clear at this time. The most obvious features of the Vitrinellidae are: a low-spired, translucent white shell; long cephalic tentacles equipped with terminal bristles and, in most cases, motile cilia; two closely-spaced pallial tentacles on the right side; a large monopectinate gill often projecting to the right of the head; a large linear osphradium; a foot with simple or only slightly indented anterior and posterior margins; a horn\ concentric, mul- tispiral operculum; and the possession of a non-glandular curved penis in the male. Some of these features (shell shape, pallial tentacles, and projecting gill) have led au- thors (e.g., Ta\ior & Sohl, 1962) to s\nonymize Vitri- nellidae and Tornidae, based on Woodward s (1898) work on Adeorbis [= Tormts] .siibcarinatus (Montagu, 1903). Others (e.g.. .\dam & Knudsen, 1969; Moore, 1972) have pointed out differences between vitrinellids and Tornus/ toniids in features of the e\ es (functional eyes are lacking in T. .'iubcarinatiis ) and, or the operculum (oval and pau- cispiral in T. siibcarinatus) and have separated the two families. In a redescription of the anatomy of T. sub- carinatus, Graham (1982:147) saw the opercular shape as the "single difference between the two nominal fam- ilies and again advocated synonymy. Additional anatomical characters of Tornidae that warrant separation from Vitrinellidae are: (1) the con- spicuous, elongate osphradium of the latter is not present in Tornus (Graham, 1982:144, found only "a small cil- iated groove, which may be a reduced osphradium"), (2) the attachment of the ctenidial axis to the mantle is short and the axis hardly supplied with blood vessels, and (3) the penis of 7". siibcarinatus bears several finger-like processes which are not known in vitrinellids as delimited here. [Fretter & Graham (1978:231) described the cte- nidium of T. siibcarinatus as "partly bipectinate." This is apparentK in error, as both Woodward (1898) and Graham (1982) described and illustrated that gill with only a single row of lamellae.] As T. siibcarinatus lives in a comparable habitat (under boulders on well-oxy- genated sand or iiuid) and is of about the same size as Circulits spp.. the drastic difference in osphradial type indicates phylogenetic difference rather than specializa- tion on a low taxonomic level. Ponder (in press) combined the "tornicl-\ itrinellid-cir- culid complex" as lamiK 'i'ornidae tor the purpose of his pin logenetic analysis of the Rissoacea. However, most of the characters and character states he attributed to that complex (metapodial tentacle present, esophageal pouches and glands present, penial glands present, os- phradium short, posterior end ot foot not simple) do not occur in N'itrinellidae as understood here, and must refer to Tornus and other tornid genera studied b> Ponder (Pseudoliotia Tate, 1898, Scrupus Finlay, 1927; unpub- lished). Vitrinellidae and Tornidae fit well into the Rissoacea, and an independent grouping of these famiilies as Tor- nacea (e.g., Kuroda et al., 1971; Golikov & Starobogatov, 1975) is not justified. The family Adeorbidae Montero- sato, 1884, used b\- some authors for members of this complex, is a s\non> m of Tornidae, since Adeorbis S. Wood, 1842, is an objective synonym of Tornus Turton & Kingston, 1830 (see Iredale, 1914:172, 1915:344). (e) The nominal family Circulidae. The taxonomic status of the nominal family Circulidae remains problematic. The family name "Circulidae" was first used b> Fretter and Graham (1962:642. ".\ppendix I"), in a list of taxa treated in that publication. The text reads merely "Circulidae: Circulus striatus (Philippi). ' Fretter and Graham (1962) did not state that they in- tended to create a new family, did not mention the name in the main bod\ of the text, even u hen the taxonomic position of the genus (1962:550, 618) and the composition of the superfamiK (1962: 622-623) were discussed, and in fact ne\er used any famiK name but N'itrinellidae when the\ referred to Ci. striatus in subsequent publi- cations (Fretter bi Graham, 1978:227; Graham, 1982: 147). Lacking an\ description, definition, or bibliograph- ic reference, a name thus introduced is not taxonomically available (ICZN, 1985: Art. 13). "Circulidae" could therefore be regarded as a nomen nudum. However, Golikov and Starobogatov (1975:211) ac- cepted "Circulidae Fretter & Graham, 1962" as a valid family and stated (1975:218) that "the characteristics of the latter famiK are found in Fretter (1956:381)," there- by referring to the summar\ of Fretter s description of Ci. striatus. This fulfills the requirement of ICZN (1985) Art. 13(a)ii (Bibliographic Reference to Published State- ment) and, unless there are earlier such statements that have escaped us, this makes Goliko\ and Starobogatov (1975) the authors of Circulidae, with Circulus as the name-bearing t\ pe. The nominal family Circulidae is, with anatomical descriptions available for Ci. striatus and Ci. texanus, much better detined than the X'itrinel- lidae, where our knowledge ot Vitrinella is based onK on shell characters and Pilsbry and McGinty's (1945a, 1946b) sketches of crawling animals (tables 1. 2). .\11 available data suggest s>non\in\ of N'itrinellidae and Circulidae (tables 1, 2; Boss, 1982:991 ). In any case, the placement of N'itrinellidae and Circulidae in separate superfamilies, or even separate superorders (Golikov & Starobogatov, 1975), is highly exaggerated. (f) Unusual features of Cyclostremiscus beauii. The stud) of ('yclustrentisciis beauii revealed a num- ber of features that differ from other members of the N'itrinellidae (and, in part, from the Rissoacea). Most of R. Bieler and P. M. Mikkelsen, 1988 Page 25 these features may be related to either its unusually large size (for a \ itrinellid) or its unusual habitat in stoniatopod burrows. Ciliation and tentacle shape: The extensive ciliation of the gills, cephalic tentacles and lower pallial tentacle provides eflective respirator) and excretory currents. On the right side of the head, where in- and outgoing cur- rents are present, water flow is controlled by the paddle- shaped tentacle. Low tides and high water temperatures are likely tc create anoxic conditions in the burrows, and a large vitrinellid such as Cyclontremiscus heauii may be more strongly affected by oxygen deficiencies than, for instance, the smaller Circuhis texanus. and thus would benefit from an elaborate s\stem to produce and direct currents. The onl\ other known commensal \itrinellid, Cochliolepis parasitica, is much smaller, and lives di- rectly on its host [under the scales of the giant scale worm Pohjodontcs lupina (Stimpson, 1856); see Stimpson, 1858; llartman, 1945:10]. Moore (1972:104) did not find cilia on the gill filaments of Cochliolepis parasitica, suggesting tliat currents produced by the annelid are sufficient to supply the snail. All other species studied live under rocks (table 2). Stomach: The rissoacean stomach does not normally have a caecum or an elongated posterior chamber, as occurs in various other prosobranchs ("it is not possible to see any trace of it in the . . . Rissoacea"; Fretter & Graham, 1962:225). OnK a few exceptions are known: Ponder (1985:78) described the stomach of Rissoina (Ris- soidae) as "very long due to elongation of posterior cham- ber," and Ponder (in press) listed the character state "posterior gastric chamber not small" for the families Emblandidae, Truncatellidae and Stenothyridae. The presence of a large posterior chamber in Cijclostreiniscus beauii, similar in relative shape and organization to that of Pomatias elegans (Miiller, 1774) (Pomatiasidae), as described by Graham (1939:90, fig. 6D), is therefore sur- prising. It may allow Cij. beauii to maintain a regular supply of food particles by regulating fluctuations in the rate of food intake (as suggested by Graham, 1939:93, for Pomatias). especially since feeding must be strongly affected b> tidal, and therefore water-level, changes within the stomatopod burrows. A relatively large animal such as Cy. beauii would be more strongly affected than smaller vitrinellids, e.g., Circulus texanus, which were observed to feed in very small pockets of water (personal observation), thus maintaining a more-or-less continuous feeding activity, as has been described, e.g., for a mem- ber of the genus Caecum (Morton, 1975:14). Hermaphroditism: The most striking result of this study was the discovery of small functional females in Cy- clostremiscus beauii with apparently functionless rem- nants of the male reproductive system. Penial structures are known to occur in various female rissoaceans (par- ticularly hydrobiids and rissoids). Thiriot-Quievreux (1977:779ff.) based her hvpothesis of sequential her- maphroditism in four species of Ris.soa on the presence of more-or-less developed penes in immature specimens and lemales. However, a later in-depth study (Thiriot- Quievreux, 1982:]67ff.) of these species through annual cycles shov\ed a seasonal (and geographical) pattern of penis-size distribution in females, but no evidence of sex change. The survey did "not support the hypothesis of a successive hermaphroditism" (1982:167). In Cyclo- stremiscus heauii, remnants of the male apparatus are only evident in the smallest functional ieniales (figure 53), with a gradual decrease of male structures with size. As outlined above, we take this as evidence for a sex change in this species rather than a simple sexual di- morphism in shell size. During ontogeny, the male re- productive system apparently disappears completely and is replaced by female organs. The anteriormost part of the pinkish-orange female albumen gland is found in the same relative position as the prostate (of similar color and reaction to staining) in the male phase. As no animal was found with a very early stage of development of the albumen gland, it cannot be decided whether these or- gans, or parts of them, are homologous. [Reid (1986), in a study of Mainwaringia Nevill, 1885, the first reported case of protandrous sequential hermaphroditism in the Littorinacea, found both a closed pallial oviduct and an open prostate in the intersexual and female stages, "sug- gesting that these structures are not strictly homologous" (1986:225). In that littorinid group, small penes are re- tained in the female phase (1986:237), and the pallial oviduct opens into the also-retained pallial vas deferens, then serving to carry egg capsules (1986:238).] With this admittedly small data set for Cy. beauii from only two localities, and the absence of data on individual devel- opment and longevity, settlement cues and adult mo- bility, several scenarios could be constructed. It is, for example, theoretically possible that functional males ar- rest growth to prolong the male phase, or that the change into the female phase occurs only after successful mating as a male. However, no evidence was found to consider this sex change as labile, i.e., environmentally mediated, as is known for other caenogastropod families such as Calyptraeidae and Stiliferidae (see Hoagland, 1978, for examples and discussion). The data are further insuffi- cient to demonstrate either seasonal or partner-induced change. The sex change in Cy. beauii appears to occur only once, at a predetermined size (figure 53; about 8 mm shell diameter, 3 teleoconch whorls), and it appar- entlv affects most, if not all, individuals (as the general shift in gender over time in the Ft. Pierce population suggests). Thus Cyclostremiscus beauii is interpreted as a pro- tandrous sequential hermaphrodite. The term sequential (= consecutive, successive) is important here. In a review of the terms protandry, protogyny and hermaphroditism, Hoagland (1984:86) defined protandry as "the function- ing of an organism first as male, then as female, with no further sex change. The two sexual phases are separated by a phase in which male primary and secondary sex characters disappear, and the animal re-differentiates as a female." This however omits those species which, after an initial male-only phase, have both male and female Page 26 THE NAUTILUS, Vol. 102, No. 1 reproductive systems developed and tiiiictional (e.g., members of Rissoellidac and Omal(>i;\ ridae; see below), i.e., protandrous simultaneous hermaphrodites. [Simul- taneous hermaphrodites, in our understanding, do not necessariiK use "the same gonad to produce both eggs and sperm" as defined b% Hoagland (1984:85).] Although, at this point, we do not know whether pro- tandrous sequential hermaphroditism is the exception, rather than the rule, in this family, the occurrence of hermaphroditism in Cyclostremiscus beauii could be in- terpreted as an adaptation to its peculiar habitat char- acterized b\ low densit\ and relative isolation. Protan- drous sequential hermaphroditism has an ad\antage for Cy. beauii, as each individual thereby minimizes the age at which it first reproduces and increases the likelihood of finding a compatible mate in a small group. Inbreeding between siblings would also be reduced (see Ghiselin, 1969, for discussion). Members of the approximately 25 families grouped under Rissoacea are general!) described as gonochoristic (see, e.g.. Boss, 1982:984), although possibly derived from ancestors that were sequential hermaphrodites (Slavo- shevskaya, 1984). Reported cases of hermaphroditism in prosobranchs (e.g., Webber, 1977:10; Fretter, 1984:15) include onl\ two genera that have classicalK been as- signed to this superfamily, Omalogyra (Omalogyridae) and Rissoella (Rissoellidac). Fretter (1948) described in detail the anatomy and reproductive biology of O. ato- muilPhilippi. 184'l)andfi. Jiap/!a(!a(Alder,'l848). Both species were found to be protandrous simultaneous her- maphrodites, with some likelihood of self-fertilization in O. atomus (1948:612, 621, 630; see also Fretter & Gra- ham, 1962:381, and 1978:218, 223). [Fretter & Graham, 1964:134, refer (erroneously:') to the .same two species as being "protandrous con.secutive hermaphrodites. '] Both families have been subsequently removed from the Ris- soacea and have been recently placed outside the Cae- nogastropoda, near (Salvini-Plawen & Haszprunar, 1987) or in (Ponder & Waren, in press) the Allogastropoda (= Heterostropha of authors). Thus, Cyclostremiscus beauii is to our knowledge the only species in the su- perfamily Rissoacea for which protandrous sequential hermaphroditism has been demonstrated. However, as sequential hermaphroditism is not as easily recognized as simultaneous hermaphroditism, it might be more widely distributed in the N'itrinellidae and/or other fam- ilies of this group. The mismatch in descriptions of the male reproductive system ol Tornus subcarinatus, where a penis was lacking according to Woodward (1898) and was found by Graham (1982), might find an explanation after all. ACKNOWLEDGEMENTS For invaluable help in the field and laboratory, we es- pecially thank William D ("Woody") Lee (SMSLP), w hose enthusiasm, expert technique and keen eye added significantly to the progress of this study. Dr. M. G. Harasewych (USNM) furnished the .scanning electron micrographs for figures 1-3. Dr Richard S. Houbrick provided valuable field assistance (he found the largest temale, without his glasses). Drs. Klaus Bandel (Univer- sitiit Hamburg, West Germany), Donald R. Moore (KSM.\S) and Winston F. Ponder (Australian Museum, S\dne\ ) offered comments on species identifications and larval shells Dr Ra\mond B. Manning (USNM) was first to bring the molluscan associates of Lysiosquilla to our attention and provided information about the stomato- pods. Dr. Robert Robertson (ANSP), Dr. Patrick Nuttall and Ms. Kathie Way [British Museum (Natural History)], Dr. Terrence M. Gosliner (CAS), Dr. Fred Thompson (Florida State Museum, Gainesville), Dr. Kenneth J. Boss (MCZ), Dr. Philippe Bouchet (MNHN), Hugh J. Porter (UNC-IMS), Dr. M. G. Harasewych (USNM), and Fred- erick J. C'ollier (USNM) provided comments on and or loans of specimens entrusted to their care. We also thank the following: Julianne Piraino (SMSLP) for SEM assis- tance; Patricia Linley (HBOI) for advice on histological techniques; Tom Smoyer for help with photographic printing; Dr. Robert Hershler (USNM), Dr. M. G. Har- asewych (USNM), Richard E. Petit (North Myrtle Beach, SO, kristen Metzger (HBOI), and Carol Browder (HBOI) for help with literature acquisition. Drs. Kevin J. Eck- elbarger (HBOI), M. G. Harasewych (USNM), Robert Hershler (USNM), and Richard S. Houbrick (USNM) are thanked for valuable comments on the manuscript. The senior author gratefully acknowledges financial support provided by a NATO postdoctoral fellowship, adminis- tered b\ the German .Academic Exchange Service (D.\AD), and research facilities provided by the Smith- sonian Marine Station at Link Port, Ft. Pierce, FL. This is Smithsonian Marine Station Contribution No. 217 and Harbor Branch Oceanographic Institution Con- tribution No. 622. LITERATURE CITED Abbott, R. T. 1954. .■American seashells. D. Van Nostrand Company, Inc., Princeton, NJ, xiv + 541 p., 40 pis Abbott, R. T. 1974. .American seashells: the marine Mollusca of the Atlantic and Pacific coasts of North .America, 2nd ed. Van Nostrand Reinhold Company. New York, 663 p., 24 pis. Abbott, R. T. and S P Dance. 1982 Compendium of sea- shells: a color guide to more than 4,200 of the world's marine shells. E. P Dutton, New York, x -I- 411 [+ 1] p., illus. Adam, W. and J. 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THE NAUTILUS 102(1 ):30-.35, 1988 Page 30 Geographical Distribution of Some Epitoniidae (Mollusca: Gastropoda) Associated with Fungiid Corals Helen DuShane Research Associate Natural History Museum Los Angeles Count) Los Angeles, CA 90007, USA mailing address: 15012 El Soneto Drive Whittier, CA 90605, USA ABSTRACT The known ranges of three coral associated epitoniids, Epito- nium costulalum (Kiener, IS39), Epitonium ulu Pilsbry, 1921, and Epitonium hulldtttm (Snwcrln, 1844) are reviewed INTRODUCTION The family Epitoniidae has had a complicated nomen- clatural history, with more than 3,000 Recent and fossils species named. The genus Epitonium is an overwhelm- ingly large group about which itiucIi has been published, but information on habitats, ecology, growth patterns, and reproduction is known for relatively few species. Some epitoniids are perhaps the only gastropods e.xcept certain coraiiiophiiidae to have feeding associations with iuiigiid corals. The stony corals comprise a large group of animals showing a great variety of form. Wells ( 1956:F388) listed 1 1 living genera in the family Fungiidae Dana, 1846, and further stated. "Within the family Fungiidae some animals are attached as juveniles, but as adults become detached and live free on rubble substrates. Others re- main attached throughout their lives." There are 11-12 genera, within w liich are probably 49 species. Fungiids live in warm seas in water temperatures 22 °-33 °C. The corallum (skeleton) is rounded or elongate, varying in length from about 5 cm to 35 cm, and in width from 5 cm to 20 cm Known commonly as "hat' or "mushroom " corals, living FuiifJia sp|). arc pink, green, off-white, or pale tan. Distribution of these corals is extensive, from the east coast of Africa, across the Arabian Sea, the Bay of Bengal, Western Pacific Ocean and including the Southern and Flastern Pacific oceans. Previous reports ol epitoniids associated with Fiingia are those of Root (1958:8), Robertson (1963:57, 1965:7, 1970:45), Bosch (1965:267), Taylor (1977:254), Kay (1979: 152), Bell (1982:508, 1985:161 ). Sabelli and Taviani (1984: 92). These papers report at least three species of epito- niids associated w ith species ol Fungia. A collection of Epitonium spp. made by SCUBA divers in the northern Red Sea verified that Fungia is "home" to the tollowing species of epitoniids: Epitonium cos- tulalum (Kiener, 1839), originally described from an unknown locality; Epitonium ulu Pilsbr\. 1921, origi- nalK described from Hawaii; and Epitonium hullatum (Sowerby, 1844), originalK described from the Philip- pines. An unidentified Epitonium sp. associated with Fungia was also reported by Sabelli and Taviani (1984) from the Red Sea. The following abbreviations appearing in the text are defined as follows: ANSP — Academy of Natural Sciences, Philadelphia. P.\. GENEVA — Museum d Histoire Naturelle, Geneva, Sw it- zerland. NHM, L.A. — Natural History Museum. Los Angeles County, Los Angeles, CA. Bratcher (Collection — Twila Bratcher, Los .Angeles, C.\. Chane)' Collection — Henry Chaney, Redondo Beach, CA. DuShane Collection — Helen DuShane, Whittier, CA. Kaiser Collection — Kirstie Kaiser, Park Citv, UT. RECORDS Epitonium costulatum (Kiener, 1839) (figures 1, 2) Discussion: Epitonium costulatum (Kiener, 1839) as far as presentK know n lives in warm seas from 10°N to SCN, from the Red Sea, Bay of Bengal (India and Thai- land), and the Philippine Islands. This is the first report of the egg capsules oi E. costulatum found on the un- derside ol Fungia sp. from the Red Sea. Each egg capsule was encrusted w ilh bits of white coral-sand and attached to another by two slender threads (figure 2). The number of egg capsules per mass is approximately 100. Hoot (1958) was the first to report this species as an unidentified eiJitoniid li\ing under Fungia, in the Sulu Archipelago, Philippines. His six specimens are at the Academy of Natural Sciences of Philadelphia (ANSP 230639) and were studied b\ Robertson (1963) who later (1970) compared them with the holot\pe in CJeneva (original locality unknown) and concluded that Root's specimens are indeed £. costulatum. The ANSP speci- H. DuShane, 1988 Page 31 4 Figure 1. Apertural view of Epitoniitm costulatum (Kiener, 1839). Length 28 mm, width 13 mm, DuShane Collection. Straits of Tiraii, Red Sea Figure 2. Coral-sand encrusted egg mass of £. costulatum. Chaney Collection. Straits of Tiran, Red Sea. Figure 3. Epitonium ulu Pilsbr\, 1921. Length 13.5 mm, width 5.5 mm, Bratcher Collection. Saudi .Arabia, Red Sea. Figure 4. £. ulu with egg mass. Length of shell 16 mm, width 11 mm, Chaney Collection. Tiran Island, Straits of Tiran, Red Sea. Figure 5. .Apertural view of Epitonium bullatum (Sowerby, 1844). Length 13 mm, width 9 mm, Kaiser Collection. Thomas Reef, Sinai, Red Sea. Figure 6. Dorsal view of E. htllatum. Kaiser Collection. Page 32 THE NAUTILUS, Vol. 102, No. 1 mens have 21-26 costae and range in length from 12 4 to 35.3 mm (Robertson, 1963, 1970). Robertson (1963:60) stated, "There are some wentle- traps which seemingly live throughout most ot their post- larval lives with (relatively) large sea anemones (or cor- als). Such species are . . . £. aff. costulatum ..." "This F.pitonitim. the oiiK wentletrap so far found w ith a coe- leiiterate other than a sea anemone, presurnabK feeds on Fungia." We now know that £. costulatum lays its gelatinous egg masses under Fungia on a sandy, rubble substrate, in depths of 2-30 m. Feeding observations are lacking. Subsequent to 1958, other specimens have been col- lected from various Indo-Pacific localities. Recent records: Ba\ of Bengal, India. One specimen, length 31 mm, with 17 costae and 12 whorls. DuShane Collection. Raya Island, Bay of Bengal, Thailand. One specimen, length 34.5 mm, with 23 costae and 1 1 \\ horls. DuShane Collection. Phuket Island. S\V Thailand, Collected by fishermen under "hat" coral, 15-20 m, 5/22/85. Three specimens, lengths 23.5, 24.5, 25 mm, with 19, 20, 26 costae and 7, 9, 12 whorls. DuShane Collection. Phuket Island, S\V Thailand. Collected by fishermen under "hat" coral, 15-20 m, 5/22/85. One specimen, length 23.5 mm, with 20 costae and 10 whorls. NHM, L.A. 124505. Tiran Island (SW), Straits of Tiran, Red Sea (27°57'N, 34°32'E). Collected by Henry Chaney, 10/31/85, SCU- BA, 2-5 m in rubble under Fungia sp., four specimens, three specimens, Chaney Collection, lengths 13, 20, 29 mm, with 18, 23, 28 costae and 8, 9, 13 whorls; one specimen, DuShane Collection, length 28 mm, with 24 costae and 12 whorls. .\\\ C^haney collected specimens were live-taken, two were pink in color, with gelatinous egg masses as described above. Thomas Reef, Sinai, Red Sea (27°59'N, 34°27'E). Col- lected by Kirstie Kaiser, 10/30/85, SCUBA, 6.1 m in sand pockets under live, detached Fungia sp., one spec- imen, length 23 mm, witli 21 costae and 11 whorls, water temperature 25 °C, live shell attached to coral. Kaiser Collection. Little Hiva, Maldive Islands. Collected by Henry Cha- ney, 8/31/86, SCUBA, 1 m reef sand, under Fungia repanda Dana, 1846, one specimen, live-taken, length 14 mm, with 20 costae and 11 whorls. DuShane Collec- tion. Epitonium ulu Pilsbry, 1921 (figures 3, 4, 7-10) Discussion: Epiloniuiit ulu l'ilsbr>, 1921, a widely dis- tributed species, lives in warm seas from 30°N to 5°S, from the Red Sea, to the Maldive Islands, New Guinea and Haw aii. It is specific to certain species of the stony coral genus Fungia. Masses of beige colored egg capsules are laid on the concave underside of Fungia spp. attached to both the coral and to adult Epitonium. Bosch (1965) reported that Fungia .scutaria Lamarck, 1816, from Kaneoke Ba\, Oahu. Hawaii, was infested with both eggs and adults of Epitonium ulu. The snails had large amounts of pink tissue containing symbiotic algal cells and nematoc\sts the\ had ingested. Taylor (1977) studied the growth rate of Epitonium ulu feeding on the sea anemone Aiptaaia sp. and found that the intracapsular development time for this species varied from five days to several weeks. She found that after hatching the ju\ eniles added approximately 0.2 mm of shell length per day. Bell (1982) observed that £. ulu produced a "mean of 32 capsules per day, each capsule containing 500-600 eggs." She later stated (Bell, 1985) that "embryos com- plete intracapsular de\elopment in six da\s at 26-27''C and hatch as planktotrophic veligers. ' Epitonium ulu has been collected recentK from five localities. Recent records: Maldive Islands. Robertson (1965) re- ported an Epitonium sp. living in association with Fun- gia. He now identifies the four specimens as Epitonium ulu (personal communication, 1986). Papua New Guinea. Collected by Tw ila Bratcher, 1980, from under Fungia sp. (figure 3), 11m, water temper- ature 28 °(]. length 16 mm, w ith 30 costae and 11 w-horls. Bratcher Collection, and one specimen, length 12 mm with 30 costae and 12 whorls. DuShane (Collection. Tiran Island (SW), Straits of Tiran, Red Sea (27°57'N, 34°32'E). Collected b\' Henry Chaney. 10/31/85. SCU- BA, 2-5 m, with egg mass, under detached Fungia on rubble substrate. Five live-taken specimens, all exuding mucus, were collected. Four specimens, Chanc\ Collec- tion, lengths 3, 4, 5, 16 mm, with 10, 11, 24, 33 costae and 9, 10, 12, 12 whorls; one specimen, DuShane Col- lection, length 6.5 mm, with 21 costae and 11 whorls, Sinafir Island, Saudi Arabia, Red Sea. (Collected b\ Twila Bratcher, 10/30/85, SCUBA, 9 m, with eggs under detached Fungia. Two live-taken specimens, lengths 9, 13.5 mm, with 17, 24 costae and 9. 10 whorls. Bratcher Collection. Thomas Reef, Sinai, Red Sea (27°59'N, 34°29'E). Col- lected by Kirstie Kaiser, 10/30/85, SCUBA, 6 m, water temperature 25 °C. .\ttached with eggs to underside of detached Fungia. 1\ ing in small sand pockets with sand and light rubble, l-'our live-taken specimens, lengths 6, 8, 15, 19 mm, with 17, 20, 23, 32 costae and 10, 10, 13, 14 whorls, all exuding mucus when collected. Kaiser Collection. All three S(CUB.'\ divers (Bratcher. Chaney, Kai.ser) collected egg masses (figures 4, 8-10) associated with specimens of Epitonium ulu from the Red Sea. The eggs were off-w liite w ith light purple spots. One egg sac con- tained 4()()-()()0 embr\()s in different stages of de\elop- ment. Each translucent egg sac w ithin the cluster is pa- pillose over the entire external surface. The papillae are softly rounded. From each egg sac three transparent twisted threads are attached at each end of the oval egg H. DuShane, 1988 Page 33 8 10 .113 mm Figure 7. Epitonium ulu Pilsbry, 1921 with egg masses on concave underside of Fungia sp. Figure 8. Egg capsules of £. ulu that appear to be empty and transparent. Figure 9. Developing, opaque embryos of £. ulu located on the inner surface of the transparent sac Figure 10. Prehatching veligers of £. ulu. Diameter of a single snail 0.113 mm. sac, and eventually twist together to form a single knotted mass. Each connecting thread appears to be many times the length of the sac itself. The egg capsules e.xamined under a microscope (300 x ) showed the young capsules in three different stages of development. Within each capsule development was uni- form. The first stage capsules appeared to be empty and transparent (figure 8). The second stage showed devel- oping, opaque, white embryos that appeared to be lo- cated on the inner surface of the sac, but not filling the entire compartment (figure 9). The third stage consisted of well-developed veligers, thus crowding the capsule (figure 10). One capsule in the third stage of development contained 400-600 free swimming veligers of equal size and development. The diameter of a single veliger was 0.113 mm. The gibbous shell is transparent e.xcept for the darkened area of the columella. In each embrvonic shell the animal appeared as a uniform gelatinous mass with two dark spots. Epitonium (Globiscala) bullatuni (Sowerby, 1844) (figures 5, 6) Discussion: Epitonium {Globiscala) bullatum (Sower- by, 1844) lives in warm seas from 35°N to 30°S, from the Red Sea, East Africa, New Guinea, Australia, the Phil- ippines, and Japan. Kilburn (1985:330-331) reported this variable species from off Southern Mozambique, and in addition to living under species of Fungia, "under rocks in low tide pools, associated with the actinian Fseudac- tinia flagellifera (Hertw.) on w hich it feeds; on occasion it ma\ be partly covered by the basal disk of the anem- one. Juvenile bullatum shelter among coralline algae, probably feeding on the small anemones that are at- Page 34 THE NAUTILUS, Vol. 102, No. 1 tached to the fronds." He synonymized Scala (Globis- cala) papyracea do Boiiry, 1912 from Natal, Epitonium (Glolmcala) woolacuttae Kersiake, 1958 from South Queensland and GlobUcala kashiuajimensis .\zuma, 1962 from Japan with £. bullatum (Sosserby, 1844). Recent records: Thomas Reef, Sinai, Red Sea (27°59'N, .34°27'E), collected by Kirstie Kaiser, 10/30/85, SCUBA, 6. 1 m, water temperature 25 °C. one live specimen from under live, detached Fungia. length 13 mm, with 40 almost imperceptible costae, 7 whorls, protoconch whorls lost, spiral striations weak when viewed under a micro- scope (10 X ), umbilicate, color white. A second live spec- imens was eaten by a wrasse (Labridae), before it could be collected. An egg mass was observed and photo- graphed with this species but not collected. New Guinea. Three specimens in the DuShane Col- lection (ex Withrow Collection), taken in 30 m, lengths 11, 11.5, 13 mm, with 8, 9, 9 whorls. Epitonium sp. An unidentified species of £pi7o;!nu>i was reported taken from under Ftingia paunwtensis (Stutchbur\-, 1833) off Saudi Arabia in the Red Sea b\ Sabelli and Taviani (1984). Three specimens in varying growth stages were collected with an egg mass at a depth of 2 m. The authors described their specimens as umbilicate with a very thin shell, 22 obsolete costae and interspaces crossed by fine spiral grooves. This is similar to the description of Epi- tonium ulu, but comparison with E. ulu is needed. The extensive paper by Jousseaume (1911) treating 58 species of epitoniids from the Red Sea is of little help in identifying species from that area. Unfortunately, his figures are too small to be of value, and some of his descriptions are vague. CONCLUSIONS With an upper surface exposed to the light and a pro- tected concave under surface, species of the genus Fun- gia serve as host for several species of epitoniids with very delicate shells, thin, fragile walls, and numerous costae that are easiK shattered. Whether the wentletraps feed on the mucus from the host polyps or the polyps themselves is unknown. Taylor (1975) concluded that Epitonium ulu can, under laboratory conditions, feed on the sea anemone Aiptasia. All other evidence indicates that E. ulu deposits eggs only under Fungia. The coral is used as the spawning site, the eggs being laid in ge- latinous masses, each capsule connected to another by two threads. The ability of these epitoniids to locate and utilize the underside of F'ungiidae requires further study. An increasingly high degree of specificity is being found w ith certain epitoniids seemingK having permanent as- sociations with Fungia corals. ACKNOWLEDGEMENTS My thanks to Robert Robertson for encouragement, and for reading the manuscript and making useful sugges- tions; to William K. Emerson and James H. McLean for reading the manuscript and offering advice; to the divers, Twila Ikatcher, Henry (^hane\ , and Kirstie Kaiser, who returned (rom the Red Sea with epitoniids that formed the backbone of this paper; to the personnel of the .\llan Hancock Foundation Library, Universit>- of Southern California, for help in locating several rare volumes; to Da\id Nhilliner and Bertram Draper for the excellent photographs; and to Kirstie Kaiser for the drawings. LITERATURE CITED Azuma, M, 1962. Descriptions of five new species of Japanese Epitoniidae. Venus 22(2);130-136, text figs. 1-6. Bell, J. L. 1982. Larval development and metamorphosis of the prosobranch mollusc, Epitonium ulu, associated with a solitary coral. Pacific Science 16:508. Bell, J. L. 1985. Larval growth and metamorphosis of a proso- branch gastropod associated with a solitar\ coral. Pro- ceedings of the Fifth International Choral Reef Congress, Tahiti 5:159-164, 6 figs. Bosch, H. F. 1965. .\ gastropod parasite of solitary corals in Hawaii. Pacific Science 19:267-268, 1 fig. Boury, E. de. 1912. Description de Scalidae nouveaux ou peu connus. Journal de Conch\ liologie 60t2):87-108, 1 pi. Dana, J. D. 1846. Zoophytes. United States Exploring Ex- pedition during the vears 1838-1842 under the command of Charles Wilkes, L .S.N., Vol. 7, p. 1-741 Philadelphia. Dana, J. D. 1849. Descriptions of fossils. United States Ex- ploring Expedition, 1838-1842, under the command of Charles Wilkes, U.S.N. Geology. By James D. Dana. \'ol. X, .Appendix, p. 681-729, pars. Atlas, xxi, pis. pars. Phila- delphia, 1849. Jousseaume, F. P. 1911[1912]. Faune malacologique de la Mer Rouge. Memoires de la Societe Zoologique de France 24:180-246, pis. .5-7. Kay, E. A. 1979. Hawaiian marine shells Reef and shore fauna of Hawaii. Section 4: Mollusca. Bernice P. Bishop Museum Special Publication 64(4). Bishop Museum Press, Honolulu, Hawaii, 653 p., 2 figs. Kersiake, J. 1958. A new Epitonium from eastern .Australia. Proceedings of the Royal Zoological Society of New South Wales for 1956-57, p.' 157-158, 1 fig. Kiener, L. 1838-39. Species general et iconographie des co- quilles vivantes; Genre Scalaire. Rousseau, Paris 7:1-22, pis. 1-7 (text: 1839; plates: 1838). Kilburn, R. N. 1985. The family Epitoniidae (Mollusca: Gas- tropoda) in southern Africa and Mozambique, Annals of the Natal Museum 27(l):239-337, 171 figs. Lamarck, de M. de. 1816. Histoire naturelle des animaux sans vertebres, Paris 2:1-568. Pilsbry, H. A. 1921. Marine mollusks of Hawaii. Proceedings of the Academy of Natural Sciences of Philadelphia 72: 360-382. Quelch, J. J. 1886, Scientific results of the vo\age of Chal- lenger. Report on the reef corals collected b\ H.M.S. Chal- lenger during the years 1873-76. London. Zoology 16:1- 203. Robertson, R. 1963. Wentletraps (Epitoniidae) feeding on sea anemones and corals. Proceedings of the Malacological SocietN of London 35(2&3):51-63, pis. 5-7. Robertson, R 1965 Coelenterate-associated prosobranch gas- tropods .•Viinual Reports of the .American Malacological Union for 1965, 32:6-8. H. DuShane, 1988 Page 35 Robertson, R. 1970. Review of the predators and parasites of stony corals, with special reference to symbiotic proso- branch gastropods. Pacific Science 24(l):43-54. Root, J. 1958. Rapa rapa in the Snlu Sea. Hawaiian Shell News 7:7-8, Sabelli, B. and Marco Taviani. Fungia-associated epitonid 20(l-4):91-94, Sowerby, G. B., II. 1844 (July) of Scalaria, collected by Mr. H. Cuming, to be figured in the fourth part of Thesaurus Conchyliorum. Proceedings of the Zoological Societ) of London, pt 12:1-38. Stuchbury, T. 1833. .\\\ account of the mode of growth of young corals of the genus Fungia. Transactions of the Linnean Society of London 16:493-498, pi. 32, figs. 6a, b. 1984 Red Sea record of a sic]. Bollettino Malacologico Descriptions of new species Taylor, J B 1975 Planktonic prosobranch veligers of Ka- neolie Bay Pli D. dissertation, I'niversity of Hawaii, Ho- nolulu, 599 p. Taylor, J. R. 1977. Growth rate in juvenile carnivorous proso- branchs (Mollusca: Gastropoda) of Kaneohe Bay, Oahu, Hawaii. Proceedings Third International Coral Reef Sym- posium Rosenstiel School ut Marine and Atmosplieric Sci- ence, University of Miami, Miami, Florida 3(l):253-259, 8 figs. Wells, J. W. 1956. Treatise on invertebrate paleontology. Part F. Coelenterata. Geological Society of America and Uni- versity of Kansas Press, xvii -I- 498 p., 2,700 figs. THE NAL TILLS 102(1 ):36-.39, 1988 Page 36 A New Species of Vasum (Gastropoda: Turbinellidae) from off Somalia William K. Emerson Waller E. Sage, III Department of ln\ertebrates American Museum of Natural History New York, NY 10024-5192, USA ABSTRACT Vasum stephanti new species is described from moderately deep water off Cape Gardafui (Ras Asir), Somalia and com- pared with congeners. INTRODUCTION In the past few years, deep-sea commercial fisheries op- erations off the northeastern coast of SomaUa have re- sulted in the discovery of several new or otherwise in- teresting species of moilusks. Lorenz (1987:11) described P.seudosiiunia wieseonim new species from the region off (^ape Ras Hafun in about 300 m, and recorded the presence oi Festilyria j estiva (Lamarck, 1811), S(romi>us oldi Emerson, 1965, and Cijpraea broderipii Sowerby, 1832, from the trawl samples. Waller (1986:39-46) de- scribed Somalipecten crannwrorurn new genus, new species, from "off Somalia, depth 150-300 m ", obtained from Taiwanese fishermen, and also provided a list of associated species. Another species recently described from off Somalia is Vulutocorbis rosavittoriae Rehder, 1981. Through the good offices ot John Bernard, our atten- tion was called to an umiamed species of Vasum trawled in Somalian waters. We take pleasure in describing this new species in honor of Adolphe Stephant, w ho obtained the specimens from Danish shrimpers and generously provided Mr. Bernard with the data and specimens. Oth- er species of moilusks reported by Mr. Stephant (in Hit., August 19, 1987) to have been taken during these trawl- ing operations include h'cstihjria jcstiva, titwrnbits oldi, S. piicatus (Roding, 1798), Phalium microstoma (von Martens, 1901), P. bituberadosnm (von Martens, 1903), Ficus investigatoris (E. A. Smith, 1894), Cytnatium ran- zanii (Bianconi, 1851), Bufonaria fernandesi Beu, 1977, Vasum crosseanum (Souserbie, 1875), Tudicula zartzi- barica Abbott, 1958, Metula bosu:ellae Kilburn, 1975, CucuUaca labiata (Lightfoot, 1786), and Chlamys tonn- sendi (Sowerb>, 1895). SYSTEMATICS Family Turbinellidae Swainson, 1840 Subfamily Vasinae H. & .\. .\dams, 1853 Genus Vasum Roding, 1798 Remarks: See Abbott (1959) and \okes (1966) for re- views of this subfamily. Vasum stephanti new species (figures 1-6) Diagnosis: Similar to Vasum tubiferum (.-^nton, 1839) in general appearance, but differs in having a more tri- angular outline, three equalK well-de\ eloped columellar plaits (in place of three major, plus one or two minor plaits), a nearly uniformly milk-w hite shell w ith a white, glazed aperture and parietal wall (compared to an or- ange-brown to yellowish shell with the parietal wall a light tan w ith \er\ large splotches of chestnut to purple- brown), and in the presence of two or three rows of spines at base of shell (instead of one row). Description: Shell moderately large for genus, attaining 108-f- mm in length. Solid, heavy, turbinate, and strongly spined. Spire ele\ated with a short, smooth, bulbous nu- cleus of 1'2 whorls (figures 5, 6). Postnuclear whorls 7 (adult specimens lack complete spires), the body whorl with 7 to 8 well-developed, curved to strongly recurved, flaringly grooved and terminally open, subsutural spines. Figures 1-6. V'a.sinn stephanti new species. 1, 2. Paratype, AMNll 225988. 3, 4. Holot\pe, AMNH 225987. 5, 6. Paratype, AMNH 225989 (details of spire). All from type locality: off Cape Gardafui, Somalia, see text; figures 1-4 approximately x %. figures 5, 6, x 2. W. K. Emerson and W. E. Sage, III, 1988 Page 37 Page 38 THE NAUTILUS, Vol. 102, No. 1 A row of similar but much shorter spines below the first row, followed by 5 coarse spiral cords and intervening raised lines. Base of shell with 2 to 3 spiral rows of moderateK developed, groove spines and lower surface with weakK developed spiral lines. Parietal wall thick- ened, slightK raised, glazed. (Columella with 3 plicae, posterior 2 better developed; first posterior plica semi- bifid in 1 specimen. Outer lip moderateK thin, slightK' reflected, crenulated. Umbilicus funnel-shaped and in most specimens widely open. Base color of shell milky white, spire stained buff. CJolumella glazed. Aperture white, with a slight bluish tinge. Periostracum moder- ateK thick, tannish brown, and somewhat foliaceous. Soft parts not seen. Operculum brown, corneous, unguiculate, apicalK nucleate, filling most of the aperture with foot fulK u ithdrawn. Inner surface marginally thickened on basal and abcolumellar sides, central area depressed and with irregular concentric rings; outer surface scabrous. Type locality: 13-16 km east, 80-96 km south of Cape Gardafui (Ras Asir), Somalia, trawled by shrimp fisher- man in 183 to 220 m, December, 1986. Range: Known only from the type localit\ and in the Gulf of .'Kden off the Bari coast of Somalia. Material examined: Holotype, AMNH 225987, 102.36 mm, ex E. Schelling Collection (figures 3, 4); paratype 2, AMNH 225988 (figures 1, 2), paratype 5, AMNH 225989 (figures 5, 6), paratype 8, AMNH 225990, ex J. Bernard Collection; paratypes 1, 3, 4, 7, 9 J. Bernard Collection; paratypes 6, 10 A. Stephant Collection, all from the t\pe locality; referred specimen, H. Lee Col- lection, Alula, Bari coast, Somalia (.see Table 1). Remarks: As noted above, Vasum stephanti new species most closely resembles in shell morphology the endemic Philippine (Cuyo-Palawan group) species V. tubiferum (Anton, 1839:70; Kobelt, 1876:155, pi. 9, fig. 3; Abbott, 1959:20, pi. 4, fig. 1; Spring.steen & Leobrera, 1986:105, pi. 28, fig. 6). Anton's taxon and the closeK related V. turbinellus (Linne, 1758:750; Abbott, 1959:17, pi. 1, figs. 2, 3), which ranges from East Africa to the western Pa- cific, are inhabitants of shallow water, as are the other four Indo-Pacific species assigned to Vasum {sensu stric- to) by .Abbott (1959). One of these, V. rhinoceros (Gme- lin, 1791 ), from Kenya and Tanzania, is somewhat similar but has a lower-spired, heavier shell with massive nod- ules, thickened and reflected outer lip, and a brown- blotched to light yellow parietal wall (Abbott, 1959:21, pi. 4, figs. 3, 4). Strongly spino.se specimens with im- mature outer lips of the Brasilian V. cassiforme (Kiener, 1840), cited from low tide to 60 m (Rios, 1985:115), are superficially similar to the new species. (See Abbott & Dance, 1982:209, 210 for polychrome illustrations of these taxa.) The Australian Altivasurn Hedle\, 1914, and sev- eral species of Indo-Pacific Tudicula H. & A. Adams, 1864 are known to occur in moderate depths (to 220 m). Some of the spinose species originalK assigned to Tu- dicula (e.g., T. zanziharica Abbott, 1958, Iron) the west- ern Indian Ocean, and T. rasilistorna Abbott, 1959), from Table 1. Vasum stephanti new species. Shell measurements in mm and number of whorls; width measured including spines, n = 12. Spires incomplete e.xcept for 5, 10 l.rliUtl] Wiiltli = \\1 Paratype 1 Parat) pe 2 Holotype Paratype 3 Parat) pe 4 Paratype 5 Paratype 6 Paratype 7 Paratype 8 Paratype 9 Referred Parat\|)c II) 107 68 106.75 102.36 97.72 97.10 95.53 86.22 78.75 73.68 66.87 63.47 56,92 97 SS 97.11 82.70 82.08 84.19 77.93 73.47 64.10 57.18 67.25 52.78 ,55 79 6 6 6 6 6 8'/4 6 5 5 5 5 4'/4 off Queensland, .\ustralia, may prove to be referable to Vasum when the soft anatomy is known. The weakK spinose V. crosseanum (Souverbie, 1875), from the In- dian Ocean, appears to be closely related to T. rasili- storna. The development of long spines in the species described herein may reflect the deeper-water habitat. ACKNOWLEDGEMENTS We are grateful to Edward T. Schelling, Shalimar, Flor- ida, and John H. Bernard, Crossville, Tennessee, respec- tively, for generously donating the holotype and two purat) pes to the American Museum of Natural Histor\-. John H. Bernard, Harr\ G. Lee, Jacksonville, Florida, and Adolphe Stephant, Lorient. France, kindK lent spec- imens. We thank each of these collectors for pro\ iding useful information. R. Tucker Abbott and M. G. Hara- sewych oftered helpful suggestions and critically re- viewed the manuscript. Stephen Butler, AMNH, con- tributed the photographs. LITERATURE CITED Abbott, R, T. 1958. .\ new Recent species of Tudicula from Zanzibar (Gastropoda: X'asidae). Notulae Naturae of the Academy of Natural Sciences of Philadelphia 305:1-4. .\bbott, R. T. 1959. The family Vasidae in the Indo-Pacific. Indo-Pacific MoUusca 1(1): 15-32. Abbott, R, T. and S P. Dance. 1982. Compendium of sea- shells, E, P. Dutton, New York, ix -(- 411 p. .•\dams, H and .-^ ,\dams. 1864. Descriptions of new species of shells chiefl) from the Cumingian collection. Proceed- ings of the Zoological Society ot London, for 1863:428- 435 (published April, 1864). Anton, H. E. 1839. Verzeichniss der Concliylien welch sicli in der Sammlung von Herrmann Eduard Anton befinden. Halle, xvi -I- llOp Gmelin, J. F. 1791. Caroli a Linne Systema naturae per regna tria naturae, 13th ed Leipzig, Vol. 1, pt. 6, cl. 6. Wrmes, p. 3021-3910. Hedley, C. 1914 Report on the MoUusca obtained 1)\ the F.I.S. "Endeavour " from the Great .\ustralian Bight and from north and south of Gabo Island. Biological results of F".I.S. "Endeavour ". Sydney, 2:65-74. W. K. Emerson and W. E. Sage, III, 1988 Page 39 kiener, L. C;. 1840[-41]. Species general et icoiiographie des coquilles vivantes. . . . Paris, Genre Turbinelle 6(59-71): 1-50, 1841; pis. 1-21, 1840 (Vasum cassijormc (Kiener) dates from the citation on plate 9 of "Turhinclla ca.ssi- formis \'alene." [= Valenciennes]; the text was pnhlislied in 1841). Kobelt, H. C 1876. Systematisches Conchylien-Cabinet von Martini und Chemnitz. ... Niirnberg. Purpur.schnecken, Band 3, Abt. 3a, pt. 251:121-164. Linne. C, von. 1758. Systema naturae per regna tria naturae, 10th ed. Stockholm, \ol. 1, Regnum animale, 284 p. Lorenz, F , Jr. 1987 Description of a new Ovulidae species from Somalia (Gastropoda: Ovulidae). La Conchiglia, Rome 19(214-215):11-12. Rios, E. C. 1985. Seashells of Brazil. Fundagao Sociedade do Rio Grande, Funda^ao Universidade do Rio Grande, Mu- seo Oceanografico. 329 p., 102 pis. Souverbie, S. M. 1875. Description d une espece nouvelle appartenant au genre Titrhinella. Jonrnal de (>'onchylio- logie 23(4):297-298. Springsteen, F. J. and F. M. Leobrera. 1986. Shells of the Philippines. Carfel Seashell Museum, Manila, 377 p. Vokes, E. H. 1966. The genus Va,si(ni (Mollusca: Gastropoda) in the New World Tulane Studies in Geology 5(l):l-36. Waller, T. R. 1986. A new genus and species of scallop (Bi- valvia: Pectinidae) from off Somalia and the definition of a new tribe Decatopectinini. The Nautilus 100(2):39-46. THE NAUTILUS 102(1 ):40-45, 1988 Page 40 Density, Spatial Distribution, Activity Patterns, and Biomass of the Land Snail, Geophorus bothropoma Moellendorff (Prosobranchia: Helicinidae) Kurt Auffenberg Troy Auffenberg Malacology Division Florida State Museum University of Florida Gainesville, FL 32611 ABSTRACT The results of preliminary work done in the Republic of the Philippines during July, 1981 on the density, spatial distribu- tion, activity patterns, and biomass of the Philippine Island land snail Geophorus bothropoma (Prosobranchia, Helicinidae) are presented. Density was estimated at 0.55/m^ utilizing the quadrat meth- od. Using the parameters of mean crowding and patchiness, the species was shown to be uniformly distributed spatially, possibly due to mutual repulsion. Individual activity distance per 24 hour period varied greatly (0.0-275.0 cm) and was possibly correlated with rainfall Utilizing the convex polygon and ellipsoid methods, minimum individual activity ranges for the duration of the study were estimated to be 2.4-4.2 m^. Biomass (live weight) of adults was estimated at 0.13 g/m'^. The species is diurnal and does not home. Key words: Gastropoda; Prosobranchia; Helicinidae; Geopho- rus; density; spatial distribution; activity; biomass; Philippine Islands. INTRODUCTION There are relatively few published studies dealing with the density, spatial distribution, activity patterns, or bio- mass of land snails (see Discussion section for citations). Of those that do exist, almost all have dealt with pul- monates of temperate regions, while tropical terrestrial prosobranchs remain virtually unstudied. The present paper reports on the results of a preliminary study con- ducted July 7-17, 1981 on Geophorus bothropoma Moel- lendorff, 1895 (Quadras & Moellendorff, 1895:148; Wag- ner, 1908:152, pi. 29, figs. 20-23), a large (13.0-16.0 mm in diameter), limestone rock-dwelling helicinid endemic to the Caramoan Peninsula, Luzon, This represents one of the very few times quantitative ecological methods have been utilized for the study of terrestrial mollusks in all of Southeast Asia. In addition, the present paper introduces to ecological malacology several analyses used by zoologists working in groups other than mollusks (i.e., birds, Odum & Kuenzler, 1955; frogs, Turner. 1960; in- sects, Alexander, 1961, Iwao, 1970; mammals, Stumpf & Mohr, 1962). While the database with which we worked was rather small, the ease ot anaKses and the applica- bility of the results suggest that such approaches to sim- ilar questions in terrestrial snail ecolog) would be highly beneficial. STUDY AREA The study area is located in the Republic of the Phil- ippines, Luzon Island, Camarines Sur Province. Cara- moan Municipality, 1.0 km south of Barrio Ilawod. The work was conducted 10 m off the trail between Ilawod and Gota Beach on a large (8 x 9 x 3 m high) limestone boulder with almost vertical sides. Much of the Caramoan Peninsula consists of well- developed limestone karst of Miocene reef origin. Be- cause the area has been relativeK recently uplifted, the mountains are rather steep. Hills and ridges often consist of masses of large limestone boulders with chasms tens of meters deep. Runoff is rapid and though rainfall may be high seasonally, the surface environment is often rel- atively dry. Surface water collects in solution pits on limestone and in hollows of trees. Due to the rugged topography, the area remains blan- keted in a multi-canopied, tropical evergreen forest. Vegetational communities are extremely diverse. The forest is dominated by tall dipterocarp trees in both upper (30-40 m) and lower (5-20 m) canopies; a dense her- baceous layer of mainK ferns exists near the ground surface. The Caramoan Peninsula has no definite dry season. While it tends to rain throughout the \ear (ca. 2,900 mm), most rainfall occurs from September through Jan- uary, with a minor peak in July associated with the onset of the typhoon season. As in other tropical rainforests, the Caramoan Pen- insula shows little seasonal temperature variation. Mean K. Auffeiiberg and T. Auffenberg, 1988 Page 41 iluil\ temperature fluctuations are greater tPian mean seasonal variation. However, there is a marked vertical tliermocline within the forest, in which temperatures from the surface to 1 m are most stable; daily variation increases at greater heights above the ground. Due to the dense vegetation at the study site, the effects of solar railiation and wind are minimal. Therefore, Geophorus butliropoma lives in the most stable part of the local warm, moist tropical forest environment. The above eco- logical data is from Auffenberg (in press). METHODS An 8 m- (2 m tall, 4 m wide) vertical grid of 1 m- quadrats was constructed against the east side of the boulder to measure density and activity. All adult Geophorus both- ropoma within this grid (N = 14) were numbered with small dots of fingernail polish on the dorsal surface of the shell. This increased shell visibilit\ , but is not believed to have increased predation due to the nocturnal habits of most potential predators. No additional individuals were located during subsequent visits. The site was vis- ited nine times during the next 11 days at 10 a.m. for appro.ximateK 1 hour observations. In addition, the site was visited sporadically throughout the daylight hours and seven times at night (8-10 p.m.). This provided a set of successive censuses, not a random quadrat sampling. Densit\ estimates are based on the ciuadrat sampling method. This method simply involves counting individ- uals occurring within a quadrat of fixed size. Analyses of spatial distribution are based on m* (mean crowding) and m* m (patchiness) of Lloyd (1967). Mean crowding is given by the formula: q - 1 (1) where x, = the number of individuals in the jth quadrat and q = the total number of quadrats. Mean crowding is defined as the mean number of other individuals per quadrat per individual. It expresses the degree of spatial crowding experienced by an individual because of others of the same species (or different species; see Lloyd, 1967). A particularly important feature of this statistic is that it is relatively independent of spatial dis- tribution t\ pe, number of samples, and size of the means. The most complete discussion concerning the utility of this statistic is by Iwao (1977). It should be stressed that this statistic does not measure crowding in an ecological sense, as man\' variables (i.e., food availabilit\', territo- rialit) ) must be examined before this can be determined (Lloyd, 1967). Patchiness (m* /m) is the ratio of mean crowding to mean densit\ (Iwao, 1968). This index provides a relative measure of aggregation. It equals unity (1) in random distribution, is greater than unity in contagious distri- butions and is less than unity in regular (uniform) dis- tributions (Iwao, 1977). Anal) sis of the activity of Geophorus buthropoma was made by subdi\idiiig the I m- quadrats, plotting the exact location of individuals and measuring straight line distances (nearest cm) from the last observation with a flexible tape. This provided a crude estimate of the min- imum distance tra\eled since the last ob.servation. Cal- culations are based only on data provided by two or more consecutive daily observations (N = 27). Estimations of activity ranges (N = 5) are based on the convex polygon method and the ellipsoid method, which is based on a covariance matrix of capture loci (Jeunrich & Turner, 1969). The convex polygon method involves plotting all the recapture points, drawing the smallest convex polygon containing these points and then determining the area. This method, defined by the equa- tion: A = x.y^+i - Xi+iYi (2) is relatively simple but is biased b\ sample size. The values tend to increase as the number of capture points increases. The ellipsoid method is not biased by sample size and assumes that individuals are active outside the observed range of activity (see Jennrich & Turner, 1969, for dis- cussion). This method is defined by; 67r|S| (3) where |S| is the determinant of the capture point co- variance matrix; S = defined by the equations; S S s s (4) 1 x;^ S„ n - 2 o 2 (y. - y)^ S. = S,. = — !— 2 (X, - x)(y, n — 2 " X - - 7v X, , y = - 2j y. (5) Live adult snails (N = 90) were collected near the study site and their weights (in groups of 10 individuals) were taken to the nearest milligram on a single beam, double pan scale. Fifty specimens were then macerated; the shells and opercula were rinsed, dried for several days and reweighed. Voucher specimens of Geophorous bothropoma are housed in the mollusk collection of the Florida State Museum (UF 56667). Page 42 THE NAUTILUS, Vol. 102, No. 1 Table 1. Densit\ and spatial distribution parameters based on quadrat method, n = individuals recaptured per visit, m/m- (lciisil\, m* = mean crowdiiij;, m* m = patchiness. Visit 6 is (irnitted from densit\ and spatial distribution analyses Visits X SE 1 2 3 4 .5 6 7 8 9 SD n 9 6 5 5 2 0 1 3 4 3.89 m/m" 1.13 0.75 0.63 0.63 0.25 — 0.13 0.38 0.50 0.55 0.11 0.32 m* 1.11 1.00 0 40 1 20 0 00 — 0 00 0 67 0.00 0.55 018 0.52 m*/m 0.98 1.33 0 6-1 1 90 (100 — 1 ) 1 )( 1 1.76 0,00 0 83 0.28 0.79 RESUl/rS Density and spatial distribution: Froiumnct'd \ariatiun in population density was observed during this study (table 1). Densities were calculated in eight quadrats for nine visits (N = 72 quadrats). \'isit 6 yielded no recap- tures and is omitted from density and spatial distribution analyses. Depending on the individual visit analyzed, mean crowding and patchiness reveal either random, contagious, or uniform spatial distributions. However, the means of these statistics suggest that individuals are uniformly distributed, for the averages of both mean crowding and patchiness are less than unity. The regression of mean crowding on mean density (figure 1 ) also suggests a uniform spatial distribution (« = y intercept = —0.14, /3 = slope = 1.25) with possible "mutual repulsion" (see Iwao, 1968, for discussion of regression analysis). Activity: Marked individuals were observed to be active during all da\ light hours. None were active during visits alter dark. .\ typical activit\' sequence consisted of an individual moving along a meandering path for several minutes, sometimes feeding on algal growth, stopping for several minutes, then continuing. Some individuals 1.8 2.0 remained at the same exact location tor 1 or 2 da\s, while for no apparent reason others remained active. Fifty-seven recaptures were recorded (50.9^ of pos- sible recaptures). Distances traveled per day varied greatly between individuals (0.0-275.0 cm). Because distances traveled rarely conform to normal distributions only the range of distances is given. Population activity variation was possiblv correlated with rainfall. Light rain did not initiate activity in in- active individuals, nor did it seem to affect individuals already active. However, snails ceased moving about if the rainfall became intense. Above average activity levels were observed between July 8 and 11 (50.0-275.0 cm, N = 11 recaptures, three visits) following intense rainfall associated with two small typhoons in the area. This in turn was followed by 5 days (July 12-16) of relatively little rainfall and reduced snail activity (0.0-65.0 cm, N = 10 recaptures, four visits). A heavy rain fell during the night of July 16, resulting in a marked increase in snail activity on July 17 (65.0-203.0 cm, N = 6 recap- tures, one visit). Perhaps the most interesting observation concerning the activity of this species is that it does not home. In- dividuals simply wander from one resting site to another, usually shallow depressions or crevices in the rock. They avoid resting sites in leaf-filled solution pits, which are, however, usually inhabited bv Cijclophorus ceratodes Moellendorff, 1895, Japonia ciliata (Sowerby, 1843), ]. stephanophora (Moellendorff, 1895), and several small pulmonate species (personal observation). 2- ,^ j %^ 1 ' ^ \ \ 1- 4=- ■:::y^cT^^--- _...^.....,;» r^ a 1 .-- Fipurp I . Rejiression of mean density (ni, nr) on mean crowd- ing (ni*) of Gi'(>i)li(inis hothropoma in study area. Curved lines represent 95% confidence limits. 12 3 4 Figure 2. Five representative activity ranges of Geophorus bothropojna plotted on 8 m- grid HIack dots represent recap- ture sites. Each polygon depicts an activity range of an indi- vidual snail ov er an 1 1 day period. K. Auffenberg and T. Auffenberg, 1988 Page 43 Estimates of individual activity ranges (N = 5) (figure 2) are quite consistent. The convex polygon method (cor- rected for sample size bias; Jennricli & Turner, 1969) yielded activity ranges of 2.3-3.8 m- (x = 3.1 ± 0.3, SD = 0.5 m-). the ellipsoid method yielded slightly (but insignificantly), larger area estimates of 2.7-4.2 m- (x = 3.3 ± 0.3, SD = 0.6 m-). Biomass: Mean total live weight per adult individual in the study area was 0.59 g (N = 90). Mean shell weight (including operculum) per individual was 0.35 g (N = 52), yielding a mean live biomass per individual of 0.24 g. The mean density estimated by the quadrat method (table 1) of this species in this area is 0.55 individuals/ m-. Thus the estimated biomass is 0.13 g/m-. DISCUSSION Density and spatial distribution: Previous studies on species comparable in size to Geophorus bothropoma have been few (i.e.. Mason, 1970; Richardson, 1975; Cameron, 1982), and none concerns terrestrial proso- branchs. The only prosobranchs with available data are the small hydrocenid Georissa monterosatiana (Godwin- .•\usten & Nevill, 1879) and the diplommatinid Opis- thostoma retrovertens Tomlin, 1938 of Malaysia. Berry (1966) found these species occurring in higher densities on moss covered rocks than on moss-free rocks, but did not address spatial distribution. In the Caramoan area we found Geori.'isa rufescens (Moellendorff, 1887) in ex- tremely localized and highly aggregated populations on vertical rock faces. This is very different from the large Geophorus bothropoma, which is found on virtually every vertical rock face and is uniformly distributed spatially. In this stud\-, intersample variation in estimated mean densities is probabK largely due to the limited size of the study area. The choice of study area size and number of samples must have some biological basis to estimate population density and spatial distribution adequately. This is usually done by preliminary sampling or guessing (Ivvao, 1977). However, we do feel confident that the proper quadrat size (1 m^) was chosen because the ob- served dail\ activity was approximately 1 m (x = 93.7 ± 13.31 cm). Density estimates were possibly also biased by the rugged microhabitat. The limestone karst provides man> cracks, crevices, and solution pits in which a snail could remain unseen, despite our thorough searches. Utilizing Iwao's (1968) interpretation of m*/m regres- sions, we determined that individuals of Geophorus both- ropoma were uniformK distributed and may have ex- hibited "mutual repulsion. Infra-specific competition has never been properly substantiated in studies on ter- restrial mollusks and we cannot substantiate it here. Nevertheless, density was relatively low, despite the seemingly adequate food and resting site resources that could have been expected to sustain substantialK' higher snail densities. .Activity: Previous studies have shown terrestrial mol- lusks to be very cyclic in their activity patterns (i.e.. Barnes & Weil, 1944, 1945; Wells, 1944; Dainton, 1954a,b; Blinn, 1963; Henne, 1963; Cameron, 1970; Crawford- Sidebotham, 1972; Baker, 1973; Bailey, 1975; Shachak et al., 1975; Heatwole & Heatwole, 1978; Deisler, 1987). It is apparent from these studies that the initiation and continuation of activity is a variable response to complex, simultaneous climatic changes (some minute, perhaps immeasurable) in the microenvironment. More field and laboratory studies must be undertaken before this will be understood. In previous studies snail movements were most numerous shortly before or after nightfall and short- ly before dawn. However, Geophorus bothropoma is diurnal rather than crepuscular, and the congener G. trochiformis (Sowerby, 1842) was also observed active throughout the day. We believe this behavioral pattern is not a general trend in tropical terrestrial prosobranchs. Cyclophorus ceratodes Moellendorff, 1895 and Japonia ciliata (Sowerby, 1843) and J. stephaiiophora (Moellen- dorff, 1895) living in the same study area are decidedly crepuscular in their activity patterns (personal observa- tion). Few data are available on activity and home site ranges of terrestrial mollusks. Heatwole and Heatwole (1978) found individual home site ranges of the camaenid Car- acolus caracoUus (Linne, 1758) to vary greatly (0.08- 59.0 m-). Since Geophorus bothropoma does not home we prefer to call the area enclosed by the recapture sites (figure 2) the activity range. The term homesite range implies that the individual possibly returns to a certain area after foraging outside that area. We assume that the activity range of Caracolus caracoUus is much larger than the enclosed polygon determined by recapture sites. Long-term study is needed to provide a meaningful estimate of the activity range of Geophorus bothropoma. The data presented here only provide an estimate of the minimum size of the activity range expected during a wet part of the year. Activity ranges are probably sig- nificantly smaller during the dry season. Homing is apparently based on chemoreception (see Cook, 1979, for review). The advantages and/or disad- vantages of homing have not been properly addressed. A permanent resting site should provide relative safety from predators and fulfill the physiological requirements of the individual at rest. The physiological and/or be- havioral basis for Geophorus bothropoma being unable to (or not having to) home is not known. Although the operculum provides protection from small predators and desiccation, this does not explain this species' lack of homing behavior. Geophorus bothropoma most com- monly rests on vertical rock faces. Even when inactive, it does not retract fully into the shell, leaving the oper- culum non-functional. Because Cyclophorus ceratodes Moellendorff, 1895 and Japonia ciliata (Sowerby, 1843) and J. stephanophoru (Moellendorf. 1895) were found to return to the same solution pits after foraging (personal observation), non-homing is not a general trend in trop- ical terrestrial prosobranchs. Biomass: Few data on the biomass of terrestrial mol- lusks are available (Strandine, 1941; Jennings & Bark- Page 44 THE NAUTILUS, Vol. 102, No. 1 ham, 1975; Richardson, 1975; Cameron, 1982) and none concern prosobranchs, nor do they pro\ ide eas\ or direct comparisons. Man\ more species must be studied before general trends can be demonstrated. Fragments of one marked specimen were found in a solution pit, possibly preyed on by the nocturnal shrew, Suncus marinus (Linne, 1766), an introduced species. This species was seen on two occasions at the study site. Many shells of Geophorus bothropoma gnawed open at the periphery were found in solution pits nearbs . The diurnal, snail-eating monitor lizard Varanti.s grayi Bou- lenger, 1885 rarely preys on this species (Auffenberg, in press). Although short-term data such as those presented here add much to our knowledge of this species, onl\' with long-term life-histor\ studies will ([uestions be answered with confidence. Combined with morphological infor- mation, sound behavioral and ecological data uill un- doubtedly contribute greatK to a better understanding ot the systematics and e\olution of Philippine helicinids. ACKNOWLEDGEMENTS We would like to thank the U.S. Fish and Wildlife Service and the New York Zoological Society for herpetological grants to Walter Auffenberg that allowed us the oppor- tunit) for the present stud>. The Philippine Parks and Wildlife office was very helpful in issuing appropriate permits. The illustrations were drawn by Armando Gar- cia and Marcos Guinaldo. We appreciate the patience, time, and insight provided bv Irvy Quitmyer, Mark Brenner, and Michael W. Binford of the Florida State Museum during the computer assisted regression anal- ysis. Glenn A. Goodfriend provided suggestions during early data analysis. Robert .\. (>ameron provided many constructive suggestions for analyses and format. We also thank Arthur J. Cain, Robert Hershler, and Fred G. Thompson for reviewing the manuscript. Special thanks are extended to our father, Walter Auffenberg, for his tireless assistance in the field and for his time and guid- ance during the writing of the manuscript. LITERATURE CITED Alexander, R D. 1961, .Aggressiveness, territoriality and sex- ual behaviour in field crickets (Orthoptera: (iryllidae). Be- haviour 17:130-223. Auffenberg, W. In press. The behavioral ecology of Gray's Monitor Lizard. University Presses of Florida Bailey, S. R. 1975. The seasonal and daiU patterns of loco- motor activity in the snail Helix asperse Muller, and their relation to environmental variables. Proceedings of the Malacological Society of London 41:415-428. Baker, A. N. 1973. Factors contributing towards the initiation of slug activity in the field Proceedings of the Malaco- logical Society of London 40:329-333. Barnes, H. F. and J. W. Weil 1944 Slugs in gardens: their numbers, activities, and distribution Part 1 Journal of Animal Ecology 13:140-175 Barnes, H. F. and j VV Weil 1945. Slugs in gardens: their numbers, activities, and distribution. Part 2. Journal of .■\nimal Ecology 1471-105 Berry, .A J 1966 Population structure and Quctuations in the snail fauna of a Malayan limestone hill. Journal of Zoology, London 150:1 1-27. Blinn, W. C. 1963. Ecolog\ of the land snails Mesodon thy- roidus and Allogona profunda. Ecology 44(3)498-505. Cameron, R. A. D. 1970. The effect of temperature on the activity of three species of helicid snail (Mollusca: Gastrop- oda). Journal of Zoolog\ . London 162:303-315. Cameron, R A D 1982 Life histories, densit\ and biomass in a woodland snail communit\ . Journal of Molluscan Stud- ies 48:159-166 Cook, A. 1979. Homing in gastropods. Malacologia 18:315- 318. Crawford-Sidebotham, T. J. 1972. The influence of weather upon the activity of slugs, Oecologia 9:141-154. Dainton, B H. 1954a. The activit\ of slugs. I The induction ot activity b) changing temperatures. Journal of Experi- mental Biology 31:165-187. Dainton. B H. 1954b The activity of slugs. II, The effect of light and air currents. Journal of Experimental Biology 31: 187-197. Deisler, J. E. 1987. The ecology of the Stock Island Tree Snail. Orthalicus reses reses (Say). Bulletin of the Florida State Museum, Biological Sciences 31(3):107-145. Heatwole, H. and A. Heatwole. 1978. Ecology of the Puerto Rican camaenid tree-snails Malacologia 17(21:241-315. Henne, F. C, 1963. The effect of light and temperature on the locomotorv activit\' of Polygyra albolahris (Sa\ ), Bios 34:129-133, Iwao, S. 1968, A new regression method for the aggregation pattern of animal populations. Research in Population Ecology 10:1-20. Iwao, S. 1970. Analysis of contagiousness in the action of mortality factors on the Western Tent Caterpillar popu- lation b\ using the m*-m relationship. Research in Pop- ulation Ecology 12:100-110, Iwao, S, 1977, The m*-m statistics as a comprehensive method for analyzing spatial patterns of biological populations and its application to sampling problems. In: Morisita. M (ed). Studies on methods of estimating population density, bio- mass and productivity in terrestrial animals. JIBP Synthe- sis, University of Tokyo Press 17:21-46. Jennings. T. J and J P Barkham. 1975, Slug populations in mixed deciduous woodland. Oecologia 10:279-286. Jeiuirich, R. I, and F B. Turner. 1969 Measurement of non- circular home range. Journal of Theoretical Biology 22: 227-237, Lloyd, M, 1967, 'Mean Crowding Journal of ,\niinal Ecolog) '36(l):l-30, Mason, C. F. 1970. Snail populations, beech litter production, and the role of snails in litter decomposition. Oecologia 5: 215-239. Odum, E, P, and E. J Kuenzler, 1955, Measurement of ter- ritory and home range size in birds. .\uk 72:128-137, (Quadras, J, F, and O, F, von Moellendorff 1895, Diagnoses specierum novarum ex insults Philippinis auctoribus, Nachrichtsblatt der deutschen Malakozoologischen Ge- sellschaft 1895(9-10):137-149. Richardson, A. M. M. 1975, Energy Dux in a natural popu- lation of the land snail, Cepaea nemoralis Linne. Oeco- logia 19(2):141-164. Shachak, M., Y. Orr. and Y. Steinberger. 1975, Field obser- vations on the natural history of Sphincterochda (S.) zona- K. Auffenberg and T. Auffenberg, 1988 Page 45 ta (Bourguignat, 1853) (=S. boissieri Charpentier, 1847). Argamon, Israel Journal of Malacology 5(l-4):20-46. Strandine, E J. 1941. Quantitative study of a snail population. Ecology 22:86-91. Stumpf, W. A. and C. O. Mofir. 1962. Linearit\ of home ranges of California mice and other animals Journal of Wildlife Management 26:149-154. Turner, F. B. 1960. Population structure and dynamics of a Western Spotted Frog, Rana p. pretiosa Baird and Girard, in Yellowstone Park, Wyoming. Ecological Monographs 30:251-278. Wagner, A. 1908, Die Familie der Jlelicinidae. In: Syste- malisches Conchylien-Cabinet von Martini und Chemnitz ia8):113-184. Wells, G. P. 1944. The water relations of snails and slugs. III. 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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 mailing offices. POSTMASTER: Send address changes to: THE NAUTILUS P.O. Box 3430 Silver Spring, MD 20901 T H E t7N AU T I L U S CONTENTS Volume 102, Number 2 April 29, 1988 ISSN 0028-1344 Joseph R. Pawlik John B. O'Sullivaii M. G. Harasewych The egg capsules, embryos, and larvae of Cancellaria cooperi (Gastropoda: Cancellariidae) Martin Avery Snyder Latirus nuirtini (Gastropoda: Fasciolariidae), a new species from Honduras 54 Robert Hershler Lee-Ann C. Havek Shell variation of springsnail populations in the Cuatro Cienegas Basin, Mexico: Preliminary analysis of Limnocrene Fauna 56 Eva Pip Niche congruency of freshwater gastropods in Central North America with respect to six water chemistry parameters 65 B. W. Kilgour Factors affecting the distribution of sphaeriid bivalves in Britannia Bav of the Ottawa River 73 Fred G. Thompson Harry G. Lee Hypselostoma holimanae new species, a pupillid land snail 78 Manuel llaimovici Eledone gaucha, a new species of eledonid octopoti (Cephalopoda: Octopodidae) from southern Brazil 82 88 Mcriot NolQCicai Uboratory LIBRARY MAY 61988 Woods Hole, Mass. THE NAUTILUS 102(2):47-53, 1988 Page 47 The Egg Capsules, Embryos, and Larvae of Cancellaria cooperi (Gastropoda: Cancellariidae) Joseph R. Pawlik Scripps Institution of Oceanography UniversitN of California, San Diego La Jolla, CA 92093, USA John B. O'Sullivan Monterey Bay Aquarium 886 Cannery Row Monterey, CA 93940 M. G. Harasewych' Department of Invertebrate Zoology National Museum of Natural History Smitfisonian Institution Washington, DC 20560, USA ABSTRACT The egg capsules, and the embr\onic and larval development of the cancellariid gastropod Cancellaria cooperi Gabb are described. Egg capsules are spatulate in form, having long, narrow stalks that support the eggs above the surrounding sand. Egg capsules contain 4,000-5,000 eggs (165 ^ni in diameter), which undergo typical prosobranch development to hatch as planktotrophic veligers after 27 da> s at 15 °C Larvae in culture grew from 305 ^m to 890 ^m in shell length over 30 days, but died before metamorphosis. Limited comparative data suggest that long stalked egg capsules are known only in members of the Cancellariinae, that opercula, absent in all adult Cancel- lariidae, are present or prominent in the late larval stages of at least some species, and that developmental type cannot be inferred from protoconch morphology using the criteria of Shu- to (1974) in a majority of cancellariid species. Key words: Reproduction; development; larvae; eggs; egg cap- sules; Cancellariidae; Cancellaria. INTRODUCTION Little is known about the reproductive biology and early development of most of the approximately 200 species that constitute the neogastropod family Cancellariidae. The few published reports (Morch, 1869; Thorson, 1935, 1944; Knudsen, 1950; MacGinitie, 1955; Kilburn & Rip- pey, 1982; Bouchet & Waren, 1985) are limited to de- scriptions of egg capsules and, in some cases, ova or larval shells attributed to cancellariids, usually on the basis of the proximit\' of living snails. During studies of the diet and feeding behavior of Cancellaria cooperi Gabb, 1865, a species that is attract- ed to and speciBcall) parasitizes the Pacific electric ray Torpedo calif arnica .\>res, 1855 (O'Sullivan e/ ai. 1987), a number of these snails were observed producing egg capsules. The present study supplements our know ledge of the natural history of this cancellariid with descrip- Author for correspondence. tions of its egg capsules and embryonic and larval de- velopment, and reviews the available data on the reproductive biology and larval development of the Can- cellariidae. MATERIALS AND METHODS Twenty-three specimens of Cancellaria cooperi were col- lected on the artificial reef "Torrev Pines #1", off San Diego, CA (32°53'12"N, 117°50'50"'w) at depths of 20- 22 m using SCUBA. The animals were maintained in an aquarium containing sufficient sand for complete snail burial (4-8 cm depth) and supplied with a continuous flow of seawater (12-16 °C). Snails were allowed to feed on electric rays on a bimonthly basis, and had been maintained in this manner for at least 6 months prior to the onset of oviposition. Individual egg capsules were freed from the aquarium bottom and maintained in beakers containing continu- ously aerated, 1 ixm filtered seawater at 15 °C. Developing embryos were removed with a glass pipette through an incision cut along the narrow edge of the egg capsule. Hatched larvae of Cancellaria cooperi were cultured following procedures described by Paige (1986), except that 1 /um filtered natural seawater containing 40 mg/ liter each of the antibiotics streptomycin sulfate and so- dium penicillin G was used instead of artificial seawater. Larvae were fed a mixture of the green flagellates Iso- chrysis galhana (Park, 1949) and Pavlova lutheri (Droop) Green, 1975 at 10^ cells/ml. Prior to photography, larvae were narcotized in a 1:3 mixture of a saturated aqueous solution of chlorobutanol in seawater. Eggs and larvae for SEM examination were fixed in 2% formalin in seawater, and stored in 70% ethanol. Specimens were critical-point dried and photographed using a Hitachi S-570 Scanning Electron Microscope. RESULTS Beginning April 21 and continuing through Ma\ 19, 1986, a total of 15 egg capsules were laid by at least three snails (mean shell length = 62.3 mm), with nine capsules being produced sequentially b>- a single female. Page 48 THE NAUTILUS, Vol. 102, No. 2 Figure 1. Cancellaria cooperi Gabb. Apertural and right side view of female specimen collected by SCUBA in 20-22 m at artificial reef "Torrev Pines #1", off San Diego, CA {32°53'12"N, !17°50'50"W), USNM 846054. 1.0 x. Oviposition generally occurred at night or in the morn- ing. Snails emerged partialK from the sand, with their raised foot spread anteriorK and enfolded posteriorly, the emerging stalk protruding from the folded portion of the foot. Over the course of several hours, the egg case emerged from the ventral pedal gland and was released, whereupon the stalk straightened and the egg case was supported well above the surface of the sand. The spatulate capsules (figure 2; table 1) consisted of lenticular egg cases supported on long, narrow (250 fim diameter) stalks. Egg capsules were roughly rectangular in transverse section, with narrow keels running along the outer edge of each corner. A pre-formed hatching aperture, containing a membranous plug (figure 2, mp), was situated at the uppermost end of each egg case. Capsules were affixed to the bottom ot the arjuarium by holdfasts that spread from the base of the stalk. Each egg case contained an estimated 4,000-5,000 spherical eggs (figures 3, 4; diameter = 164.5 ± 6.7 ixm, N = 10), suspended in a clear, gelatinous matrix, all of mp Figure 2. Egg capsule of Cancellaria cooperi Gabb. Frontal and side views 1.0 x. detail of hatching aperture 6.0 x. mp, mucous plug; li, membranous sack. which was enveloped in a membranous, transparent sack (figure 2, li). The lenticular walls of the egg case were slightly concave, creating a constriction along the mid- line of the case that displaced the eggs to either side. Spiral cleavage commenced within 12 hours of ovi- position, and the 8 cell stage (figure 5) was reached by the second day. Thereafter, the embryos became in- creasingly irregular in form (figures 6-8). All the embryos within an egg case underwent de\elopment; there were no nurse eggs or unfertilized eggs in the cases examined. By 10 da\s after deposition, the stomodeal in\agination was e\ident (figure 9). .\fter 12 da\s, the protoconch and operculum, both of conchiolin, were clearly discernable (figures 10, 11), and torsion was complete after 14 days (figures 12-14). The velar lobes were formed and in- creasing in size by the 16th day (figures 15, 16). On the Figures 3-14. Embryonic and larval development of Cancellaria cooperi Gabb at 15 °C. 3. Living etnbr\os, 1 day old 4. One- (l.i\-(]ld embryo, critical-point dried. Scale bar = 25 ^m. ,5. lJ\iiig embrxos, 2 days old. 6. Living embr\o, 4 days old. 7. Four- da\-old embryo, critical-point dried Scale bar = .50 fim. 8. Living embr\os, 8 days old. 9. Ten-dav-old embr\o. critical-point dried. Scale bar = 50 /nm 10. Li\ing embryos, 12 days old 1 L Hight side and ventral views of same 12-da\-old embr\o, critical- point dried. Scale bar = 50 ^m. 12. Living embryos, 14 days old \'.i. 14. X'cntral (13) and dorsal (14) views of 14-da\-old embrsos, critical-point dried. Scale bar = 50 ^m asr, apical sensory region; dml, dorsal maiille lip; Ik, larval kidney; o, operculum; pb, polar body; pc, protoconch; pt, prototroch; s, stomodeum. J. R. Pawlik et ai, 1988 Page 49 Page 50 THE NAUTILUS, Vol. 102, No. 2 Figures l,'j-22. Embryonic and lar\al development of Cancellaria cooperi Gabb at 15 °C. 15. Living embryo, 16 days old 16. Sixteen-da\-old t'nibr\o, critical-point dried. Scale bar = .50 ;um. 17. Li\ing. newK -hatched larva with carmine particles in the gut. 18. Shell ultrastrticture of newK-hatched larva, plane of fracture parallel to growing edge. Scale bar = 2 nm 19. .^pertural, dorsal and apical views of shells of newly-hatched larvae. Scale bar = 100 ^in. 20. Living larva, 30 days after hatching 21. Shell and operculum of larva, 30 days after hatching. Scale bar = 250 fim. 22. .-Vpical portion of adult shell (LACM 40-95.1), arrow- indicating transition from protoconch to teleoconch, scale bar = 500 fim. mo, month; o, ()j)crculuni; po, posterior ciliary band; pr. preoral ciliar\ band; sto, storiiach; vl, velar lobe. 20tli day after capsule depobitiou, eiiibr\ os began to move more freely within the egg case. The gelatinous matrix in which the developing embrvds had been suspended became less viscous, and the swimming enil)ryos aggre- gated randondy w illiin the case. ,\ftor an average of 27 da\s at 13 °(.' the nicnibrancjus plug occluding the hatch- ing aperture dissolved, and swimming larvae escaped. Shells ol the new K hatched veligers (figures 18, 19) had a mean diameter of 304,6 /um (N = 10, SD = 3.5), and were 3.9 ^m thick. The veligers possessed an operculum J. R. Pawlik et a/., 1988 Page 51 Table 1 . Measurements of egg capsules of Cancellaria cooperi Gabb. All measurements in mm (N = 10) Character Mean Range SU Total length 79.6 70.5-S3.6 4.8 Capsule length 30.1 27.8-32.8 1.9 Capsule width 11.4 10.7-12.4 0.6 Capsule thickness 1.8 1.6-2.0 0.2 _i Stalk length 49.5 37.7-54.0 6.0 O > Maximum diameter of holdfast 9.1 7.4-lO.N 1.2 (figure 19, o), and a fully functional alimentary system. When added to a small dish ot seawater containing sus- pended carmine particles, the veliger larvae rapidly filled their guts with these particles (figure 17, sto). Attempts to rear these veliger larvae through meta- morphosis were unsuccessful. At 20 °C, larvae grew rap- idly, reaching a mean shell diameter of 644 ^m (figure 20) 22 days after hatching. Thereafter, the larvae began to die, with only a single larva surviving 30 days after hatching (shell diameter = 890 nm. figure 21). Larvae that had survived more than 22 da\s after hatching de- veloped propodia, but did not metamorphose in the pres- ence of fresh or frozen Torpedo mucus, or in the presence of sand from an aquarium containing adult snails. No crawling or search behavior associated with the onset of metamorphic competence was observed. Protoconchs of adult shells of Cancellaria cooperi indicate that the larval shell reaches 3.3 whorls (shell diameter = l,160;um) prior to metamorphosis (figure 22; table 2). DISCUSSION Egg capsules of Cancellaria cooperi resemble those of man\ neogastropods (e.g.. D'Asaro, 1970; Radwin & Chamberlin, 1973; Bandel, 1976), with notable modifi- cation in the length of the supporting stalk. This elon- gation of the stalk appears to be an adaptation for un- stable sediments in which capsules are deposited. Under natural conditions, egg capsules are most likely attached to buried stones or shells, with the long stalk supporting the egg case well above the sand surface, preventing its burial, and possibly protecting the eggs from small, bot- tom-dwelling predators. The compressed, spatulate form of the egg case may serve to increase the surface area available for diffusion of gases and waste products be- 5.0 4.0 3.0 2.0 1.0 PLANKTOTROPHIC 8 • 1 4o05 7o o9 o10 o6 -^ LECITHOTROPHIC 0.0 0.1 0.2 0.3 0.4 0.5 0.6 D / VOL Figure 23. Relationship of the number of whorls (Vol) and the ratio of maximum diameter to number of whorls (D/V'ol) of cancellariid protoconchs. Solid circles denote species for which type of development is known or inferred on the basis of num- ber of ova per capsule. Open circles denote species for which type of development is unknown. 1, Cancellaria cooperi, 2, Trigonostoma foveolata. 3, .\clnicte viridula: 4, Cancellaria reticulata: 5, Cancellaria spengleriana. 6, Trigonostoma sca- lare: 7, Olssonella smithii. 8, \arona ntitraeformis: 9, Scalptia obliquata; 10, Cancellaria similis. tween the egg case and the surrounding seawater. Cap- sules were most frequently laid with the broad face of the case oriented into the stream of flow ing seawater. The egg cases of Cancellaria cooperi are most similar in morpholog} to those reported by Knudsen (1950: fig. 18j for Cancellaria sp., and to his account of the egg cases of Cancellaria spengleriana (Deshayes, 1830). All have the characteristic long stalk, but the latter two are described or figured as being hemi-elliptical rather than lenticular in profile, and triangular rather than rectan- gular in transverse section. Egg cases of Trigonostoma joveolata (Sowerb> , 1848), a species occurring "in sand or gravel among rocks in low-tide pools , are similar to those of Cancellaria cooperi in shape, but are smaller in size, and have a proportionally shorter stalk (Kilburn & Rippey, 1982:115). Capsules of Admete viridula (Fabri- cius, 1780), a subtidal boreal species, are attached directly to the substrate and lack a stalk [Thorson, 1935; fig. 71 Table 2. Protoconch measurements of the three cancellariid species for which the mode of development is known or inferred based on number of ova per capsule. Measurements are presented in the format mean/standard deviation D = diameter in mm: Vol = number of whorls or volutions, measured according to Jablonski and Lutz (1980:332). Species D \nl D Vol Cancellaria cooperi. LACM 40-95.1; LACM 39- 94.1; LACM 39-116.2 (\ = 4) Trigonostoma foveolata: XM C8393; NM C8394; \M B7651 (N = 5) .\dmetc viridula: USNM 189720 (N = lOt 1.16/0.02 1.33/0.21 0.78/0.05 3.29/0.02 2.24/0.21 2. 12 '0.10 0.35, 0.01 0.59 0.08 0.37 0.01 Page 52 THE NAUTILUS, Vol. 102, No. 2 Table 3. Protoconch measurements for cancellariid species for which mode of development is not known Data are presented in the format of mean/standard deviation. D = diameter in mm; \'(il = number of w horls or volutions, measured according to Jablonski and Lutz (1980:332). Species 1) V„l D \ ol Cancellaria reticulata: L'SNM 619108 (N = 10) C-ancellaria spengleriana. USNM 664965; USNM .344417 (N = 6) Trigonnstoma scalare: USNM 846304 (N = 1) Olssonella smithiU USNM 806986; USNM 450577; USNM 667720 (N = 5) Sarona mitraeformis: Petit collection (N = 3) Scalptia ohiiquala: L'SNM 629063 (N = 4) Cancellaria similis. USNM 664967 (N = 5) 0.99/0.11 2.90/0.06 0.34/0.01 1.08/0.07 0.96 3.02/0.09 2.0 0.36/0.02 0.48 0.85/0.04 1.06/0.03 0.89/0.03 1.26 0.06 2.62/0.16 3.60/0.15 2.45/0.09 2.75 0,00 0.33/0.02 0 29 0.00 n )(i 0.01 (14(1 0,02 (as Velutina iindala Brown, see Thorsoii, 1944); Bouchet & Waren, 1985: fig. 687]. The egg capsules of all can- cellariids studied to date have roughly elliptical, parallel sides w ith strongly to weakly keeled margins, and a me- dial, dorsal hatching aperture. Capsules with very long stalks appear to be restricted to the subfamily Cancel- lariinae. De\elopment oi Cancellaria cooperi is similar to that ot Thais hacniaatuma jiuridana as described by D'Asaro (1966), although C. cooperi takes about 80% longer to reach comparable developmental stages, and does not produce a noticeable sinusigeral ridge. It is interesting to note the presence of an operculum, particularly prom- inent in the planktotrophic larval stage (figure 21), in a family noted for the absence of opercula in adults. The present study comprises the first direct observation of oviposition and development of any species of can- cellariid, although the mode of development can be de- duced in several cases from previousK' published data on capsule contents. Thus, Cancellaria sp. (30-40 ova/ capsule, 500 /jm in diameter; Kiiud.sen, 1950:109), Tri- gonostovia foveolata (16 larvae/ capsule; Petit & Hara- sewych, in preparation), Admete viridula (6-7 larvae/ capsule; Thorson, 1935:67) and Admete sp. (6 larvae/ capsule, capsule referred to by MacGinitie, 1955:51, USNM 664468) all likely undergo lecithotrophic devel- opment, as indicated by the low number of large larvae or ova per capsule. To date, Cancellaria cooperi is the only cancellariid known to undergo planktotrophic de- velopment. In the absence of direct information, gastropod larval development may be inferred from the morphology of the protoconch at the apex of the adult shell. Thorson 's "apex theory" (Thorson, 1950; Jablonski & Lutz, 1980, 1983) asserts that a large, rounded, paucispiral proto- conch indicates non-planktotrophic larval development, while a narrow, polygyrate, sculptured protoconch sug- gests planktotrophic de\elo[)meiit. In more tiuantitative studies of this relationship, Shuto (1974) found that the ratio ol the maximum protoconch diameter (D) to the number of protoconch whorls (Vol) was a reasonable indicator of developmental type. \'alues greater than 1.0 were indicative ol lecithotrophic larvae, while values below 0.3 were more characteristic of planktotrophic larvae, especialK it the protoconch consisted of three or more whorls. Species with D \'ol ratios between 0.3 and 1.0 usually have lecithotrophic larvae if protoconchs con- sist of less than 2'/i whorls. \ plot of \'ol r,s. D, \'ol values for 10 species of cancellariids (figure 23) indicates that although protoconch morphologv appears to be an ac- curate indicator of the mode ol larval development for those species of Cancellariidae that fall within the di- agnostic regions proposed b\ Shuto (1974), develop- mental type cannot be inferred for the majority of can- cellariid taxa using these criteria. As more information on the life histories and diets of additional species of cancellariids becomes available, the relationship between the mode of larval development and the mobility and patchiness of prey species distri- bution may prove fruitful ground for investigation. ACKNOWLEDGEMENTS We thank R. R. McConnaughey for assistance in col- lecting and maintaining animals, and R. E. Petit for providing information on the Cancellariidae, and for critical review of the manuscript. Susann Braden took the Scanning Electron Micrographs. LITERATURE CITED Bandel, K. 1976. Morphologie der Gelege und okologische Beobachtungen an Buccinaceen (Gastropoda) aus der siid- lichen Karibischen See. Bonner zoologische Beitrage 27: 98-133. Bouchet, P. and A. Waren. 1985 Revision of the northeast Atlantic bathyal and abyssal Neogastropoda excluding Turridae (Mollusca, Gastropoda). Bollettino Malacologico KSuppl.): 123-296. D'Asaro, C. N. 1966. The egg capsules, embryogenesis. and early organogenesis of a common oyster predator, 7'/iais haetnastorna floridana (Gastropoda: Prosobranchia). Bul- letin of Marine Science 16(4):884-914. D'Asaro, C. N. 1970. Egg capsules of prosobranch mollusks from south Florida and the Bahamas and notes on spawn- ing in the Jaborator), Bulletin of Marine Science 20:415- 440 Jablonski, D. and R A. Lutz. 1980. Molluscan larval shell morphology: ecological and paleontological applications. J. R. Pawlik et al, 1988 Page 53 In: Rhoads, D. C. and R. A. Lutz (eds.). Skeletal growth of aquatic organisms: biological records of environmental change. Plenum Press, New York, p 323-377 Jabloiiski, D. and R. A, Lutz. 1983. Larval ecolog\ ot marine benthic invertebrates: paleobiological implications. Bio- logical Reviews 58:21-89. Kiiburn, R and E Rippey. 1982. Sea shells of southern Africa McMillan South Africa, Ltd., Johannesburg. 249 p Knudsen, J. 1950. Egg capsules and development of some marine prosobranchs from tropical west Africa. Atlantide Report 1:85-130. MacGinitie, G. E. 1955. Distribution and ecology of the ma- rine invertebrates of Point Barrow. Alaska. Smithsonian Miscellaneous Collections 128(9):1-201. Morch. O. \ L. 1869. Catalogue des Mollusques du Spitz- bergen recuillis par H. Kroyer. Memoire de la Societe malacologique de la Belgique, Tome 4, Bru.xelles. O'Sullivan, J. B., R. R. McConnaughey. and M. E. Huber. 1987. A blood-sucking snail: the Cooper's nutmeg, Cancellaria cooperi Gabb, parasitizes the California electric ray. Tor- pedo californica .\yres. Biological Bulletin 172(3):362-366. Paige, J. A. 1986. The laboratory culture of two aplysiids, Aplysia brasiliana Rang, 1828, and Bursatella leachii plei (Rang, 1828) (Gastropoda: Opisthobranchia) in artificial sea water. The Veliger 29(l):64-69. Radwin, G E. and J. L. Chamberlin. 1973. Patterns of larval development in stenoglossan gastropods. Transactions of the San Diego Society of Natural History 17(9):107-117. Shuto, T. 1974. Larval ecology of prosobranch gastropods and its bearing on biogeography and paleontology. Lethaia 7: 239-256. Thorson, G. 1935. Studies on the egg-capsules and develop- ment of Arctic marine prosobranchs. Meddelelser om Gronland 100(5):1-71, Thorson, G, 1944. The zoology of east Greenland: marine gastropoda prosobranchiata. Meddelelser om Gronland 121(13):1-181. Thorson, G. 1950. Reproductive and larval ecology of marine bottom invertebrates. Biological Reviews 25:1-45. THE NAUTILUS 102(2):54-55, 1988 Page 54 Latirus martini (Gastropoda: Fasciolariidae), a New Species from Honduras Martin Avery Snyder 7-4.5 Newtown Road \'illanova, PA 19085 ABSTRACT Latirus martini new species is described from shallow water off KoalaM Island. approximateK 40 miles north ot the Hon- duras mainland. This ne« ta.xoii differs from its nearest Carib- bean relative, Latirus angulatus (Roding, 1798), by its sculp- ture, coloration, shape, and size. The 13-16 axial ribs on the body whorl constitute roughly twice the number found in other Caribbean members of this genus INTRODUCTION In the summer of 1985 10 specimens of a new Latirus were taken under coral rubble b\ divers off the north coast of Roatan Island, Honduras. These shells were ob- tained by Mr. Thomas Honker of Florida, who kindly passed them on to the author. The specimens were all collected alive, the soft parts discarded, and the opercula glued back in place on cotton. For this reason no soft parts were examined, although the opercidum is de- scribed. Since that time, some additional specimens have been taken from the same locality. Specimens of the new species are deposited in the collections of the Academx of Natural Sciences of Phila- delphia (ANSP), the Delaware Museum of Natural His- tory (DMNH), and the National Museum of Natural History, Smithsonian Institution (USNM). .additional specimens are retained in the collection of the author. Family Fasciolariidae Gray, 1853 Subfamily Perislerniinae Trvon, 1880 Genus Latirus Montfort. 1810 Type species: Latirus auraiitiacus Montfort, 1810, In nionut) p> [= L. gibbulus (Gmelin, 1791 j]. Latirus martini new species (figures 1, 2) Description: Shell heavy, small to medium in size (,21.7 mm to 38.4 mm in length), somewhat squat, with spire iiearK ' s length of shell; profile inflated, w ith 8-9 whorls; protoconch (figure 2) of 1 '/2 whorl, smooth, bulbous, translucent pale orange-brown in color; aperture oval to squarish, greater in length than siphonal canal; anal canal weakly developed; axial sculpture of 13-16 prominent ribs, crossed by numerous, pronounced spiral cords with grooves between; cords alternateK larger and smaller, first t\\ o on body whorl about ecjual in thickness, forming ridge and deep suture; approximateK 45 cortls on body whorl running onto anterior end of siphonal canal, 25 cords on the penultimate whorl, with every fifth cord somew hat stronger than others; spiral cords darkish or- ange-brow n turning to dark brow n between axial ribs; grooves between cords light caramel brown w ith yellow cast; shell appears dark orange-brown, with lighter axial ribs; columella with 3-4 distinct plicae (figure 1); teeth translucent, shiny, white; outer lip crenulated, with in- dentations corresponding to spiral sculpture; smooth por- tion of inner lip extending approximately to opposing side of the first axial rib, followed anteriorly by 14-16 irregular w hite lirae on inside of bod\ w horl; operculum \ellow -brow II in color, chitinous, nearK filling aperture. Type locality: 15-20 feet, under coral rubble, north coast, Roatan Island, Honduras, summer, 1985. Type material: Holotv pe, ANSP 361064 (27.5 mm); paratype 1, DMNH 169442 (23.8 mm); paratype2, USNM 859070 (26.9 mm); paratypes 3-5 in the author's collec- tion (34.0 mm. 24.8 mm, 23.6 mm). .\11 paratv pes from the t\ pe locality. Etymology: The species is named for the author's eldest son. Discussion: This species appears to be most closeK re- lated to the highly variable Latirus angulatus (Roding, 1798). Several forms of the latter were illustrated by Bullock (19(58, 1974). Specimens of /.. angulatus from the Swan Islands, approximateK 120 miles north ot Hon- duras (Bullock, 1968: fig. 5, plate 2), and a specimen from the northern coast of South .\merica (Bullock, 1974: fig. 21) are superficialK similar to L. martini. The col- oration is similar but the shape and sculpture are com- pletel) typical of L. angulatus and thus readiK distin- guishable from L. martini. Latirus angulatus has 7-9 axial ribs, about half the iiund)er of /.. martini. The spiral cords on L. angulatus luc weaker than those of L. mar- tini. The tvpical coloration is also quite different. In a M. A. Snyder, 1988 Page 55 Figures 1. 2. Lalinis martini new species. 1. Holotype, ANSP 361064. 2. EarK « horls of parat\ pe, DMNH 169442, both from north coast of Roatan Island, Honduras, under coral rubble in 5-7 m. dark brown specimen of L. angulatits, the raised cords and that portion of the whorl near the suture are dark brown, in areas between cords where there is fine or- namentation, the shell is light cocoa-tan to orange-brown. Generally, L. angulatus is a more elongated shell with the spire usualK- more than half the length of the shell. Possilile confusion could also occur with Leucozonia nas.sa (Gnieliii, 1791 ) which is somewhat similar in pro- tile and coloration. This shell lacks the strong a.xial sculp- ture of L. martini, and has a thick, black-brown oper- culum. A characteristic narrow \\ hite band at the base, commonly terminating in a small spine on the outer lip, serves to distinguish this species from L. martini. Finally, confusion might arise with the recently-de- scribed species Latirus vermeiji (Petuch, 1986). Latirus vermeiji has less pronounced surface sculpture, is dis- tinctlv orangish in color, and has a caramel-orange col- ored inner lip, whereas the inner lip in L. martini is yellowish brown. The roughly even spiral cords in L. vermeiji are more pronounced with every other cord being white in color. LITERATURE CITED Bullock, R. C. 1968. The fasciolariid genera Latirus, Doli- cholatirus. and Teralatinis (Mollusca: Gastropoda) in the Western .Atlantic. Master s thesis, Universit\ of Maine, Orono, 109 p., 8 pis. Bullock, R. C. 1974. A contribution of the systematics of some West Indian Latirus (Gastropoda, Fasciolariidae). The Nautilus 88(3):69-79, 26 figs. Gmelin,J. 1791. Systema naturae, 13th ed. Part 6:3021-4120. Montfort, P. D. de. 1810, Conchyliologie systematique et classification methodique des Coquilles ... 2. Paris, 676 p. Petuch, Edward J. 1986. New South American gastropods in the genera Conus (Conidae) and Latirus (Fasciolariidae). Proceedings of the Biological Society of Washington 99( 1 ): 8-14. Roding, P. 1798, Museum Boltenianum, Hamburg, 199 p. Tryon, G. W. 1881. Manual of conchology 3. Tryon, Phila- delphia, 310 p., 87 pis. THE NAUTILUS 102(2):56-64, 1988 Page 56 Shell Variation of Springsnail Populations in the Cuatro Cienegas Basin, Mexico: Preliminary Analysis of Limnocrene Fauna Koberl Hershler Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washiniitiin, DC 20560, USA Lee-Ann C. Ilayek Mathematics and Statistics National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA ABSTRACT Geographic variation in shell morphometry is analyzed for three locally endemic springsnail (Gastropoda: Hydrobiidae) species occurring sympatrically in nine limnocrenesof the Cua- tro Cienegas Basin, Coahuila, Mexico. Despite some correlation of size-related variables across species, groupings of populations based on multivariate analyses were not very similar among species, nor were they strongly concordant with current drain- age configurations in the basin. Groups of populations of Mexi- pyrgu.s churinceanus Ta\ lor having different patterns of shell sculpture and color banding (and once considered separate species) were not separated similarK on basis of shell size and shape. Inter-population differentiation of these snails was ap- proximately equivalent to that of Symphuphilus minckleyi Taylor, whereas Mexithaunia quadripaludium Taylor was less variable INTROULCniON One of the more remarkable aciuatic faunas of the New World occurs in the small (1,200 km-), intermontane valley of Cuatro Cienegas, Coahuila, Mexico, which har- bors at least 26 locall) endemic forms (Cole, 1984; McCoy, 1984; Minckley, 1984; Hershler, 1985). Local aquatic taxa show a great diversity in extent of differentiation relative to adjacent biota, ranging from slightK differ- entiated pojMilations to highly divergent genera, sug- gesting both long-term persistence of aquatic habitat and multiple invasions of the valley over a broad time scale (Minckley, 1969). .\quatic organisms are deployed among diverse, spring-fed acjuatic habitats that comprise h\'e to seven local drainage systems (Minckle\ , 1969; LaBounty, 1974), providing what has been termed a "matchless natural laborator> " (Taylor & Minckley 1966:22) for eco- logical and cvolutionars- study. Spriiigsnails (C»astropoda: Hydrobiidae) of the basin are diverse [nine genera (five endemic), 13 species (nine endemic); Hershler, 1985], and occur abundantly in a large number of easiK' accessible sites, providing an ex- cellent (>pportunit\ to study geographic variation of pop- ulations, the analysis of w hich is considered crucial to understanding the speciation process (Gould & Johnston, 1972; Endler, 1977). To date, researcii on this snail fauna has largeK been taxonomic (Ta\ lor, 1966; Hershler, 1985), although geographic variation of one endemic species was partly analyzed (Hershler, 1985; Hershler & Minck- ley, 1986). Taylor (1966) and Taylor and Minckley (1966) noted apparent diversity in extent of differentiation among local species: Mexipyrgus Taylor, an endemic restricted to large (> 25 m-) springpools (limnocrenes) and stream outflows, is variable enough to have been origiiialK considered as six nominal species (Ta\lor, 1966; synonymized to monotypy by Hershler, 1985), whereas other snails appear morphologically uniform, at least in the portion oi the basin that has been well studied (i.e.. all but the southeastern lobe; Hershler, 1985). It was suggested that heightened differentiation of Mexipyrgus resulted from marked discontinuity of its habitat: . . it seems that habitat of this genus is more likely to be discontinuous than that of other snails in the area. Mexipyrgus lives in soft flocculent ooze or mud in the lagunas, thus not in the shallows where wave action re- moves the fine particles Extensive marsh\ areas with small streams connecting larger water bodies provide no suitable widespread habitat. (Taylor, 1966:188) Variation within Mexipyrgus has largeK- been dis- cussed in terms of shell sculpture and color banding (Taylor, 1966), characters absent from or poorl) devel- oped in other local snails, and there has been no attempt to contrast intraspecific variation among members of the snail launa using a set of common characters, such as shell morphometric variables. In this paper we provide such a comparison between Mexipyrgus churinceanus Taylor and the two other species (both local endemics) common in basin limnocrenes. Mexithaunia quadripa- ludium Ta\ lor and S'yniphophilus ininckU'yi Ta\ lor (see figure 2). Specifically, we seek to answer the following questions: 1) Do these distantly related snails (Hershler, 1985) show commonalitN of pattern of geographic vari- ation? 2) Does shell morphometric variation among pop- R. Hershler and L.-A. C. Havek, 1988 Page 57 Figure 1. Map of the central portion of the Cuatro Cienegas Basin, show ing major drainage features and collecting localities (numbered as in table 1 ), The inset (lower right) shows locations of the state of Coahuila (dashed line) and Cuatro Cienegas (dot) within Mexico. ulations of Mcxipyrgus churinceanus exceed that of the tv\o other limnocrene species (above) that occur s\ m- patrically with this species? 3) Are Mexipyrgus popu- lations that are well differentiated in terms of shell sculp- ture and color banding patterns similarl\ separated by shell size and shape variation? MATERIALS AND METHODS Nine limnocrenes were sampled (shown in figure 1 and described in the Appendix), representing the majority of springpools in the study area (all of basin excluding south- eastern lobe) where all three forms are common. Only isolated sources (Sites 1-4, 9) or, in cases where springs were connected by stream, upflow pools (Sites 5-8) were considered, in order to reduce possible effects of gene flow from contiguous populations (Hershler & Minckley, 1986). These springs belong to four separate drainage systems of the basin and harbor forms of Mexipyrgus referable to four nominal species (see belowj. Mexipyrgus churinceanus was collected by sieving soft substrates, while the other two species, associated with hard substrates, were gathered by w ashing travertine and macrophytes in a bucket. Material was fixed in dilute formalin, and preserved in 70!^ ethanol. Figure 2. Scanning electron micrographs (printed at same enlargement) of cleaned shells ol springsnails from Laguna Tio Candido, Cuatro Cienegas, Mexico: a, Mexipyrgus churin- ceanus (shell height, 6.34 mm); b, Nymphophilus minckleyi (6.45 mm); c, Mexithauma quadripaludium (6.22 mm). For each species, about 15 live-collected, fully mature adults, recognizable by their complete and thickened inner shell lips, were randomly selected from collections from each site and dried for morphometric analysis. Af- ter whorls were counted (WH), shells were imbedded in clay in standard apertural aspect (figure 2) and shell outlines were draw n using a camera lucida mounted on a WILD M-5 dissecting microscope (12 x or 25 x ). Points on these drawings were digitized and values for the fol- lowing "standard" shell parameters (1-4) and shell shape descriptors (5-8) (from Raup, 1966, and elsewhere) were generated: 1) Shell height (SH) 2) Shell width (S\V) 3) Length of bod\ whorl (LEW) 4) Width of body whorl (WBW) 5) Translation rate (T) 6) Whorl expansion rate (W) 7) Distance of generating curve from coiling axis (D) 8) Aperture shape (SA) A calculated variable (S), consisting of the addition of SH and SW, was generated to serve as a more realistic measure of size than either shell length or width. Cal- culation of shape parameters largely followed methods of Kohn and Riggs (1975), with the exception being W, which was measured as the mean of a series of squared ratios of perpendicular distances from coiling axis to sutures (shell in apertural and not apical aspect) at half whorl intervals. The apertural suture was not used, due to frequent loosening of coiling during last half whorl of growth, nor were sutures used from eroded adapical sec- tions of the spire. Digitizing was done using the CONCH software program (Chapman et ai, 1988; methodology fulK described therein) and a GTCO Micro-Digi Pad 12x12 linked to a KAYPRO 2000 microcomputer. Descriptive statistics for all morphological variables were obtained for each species and locality. The hy- potheses of homogeneity of mean differences and vari- ances across localities were tested for each species. An ANO\"A model was selected for each variable of each Page 58 THE NAUTILUS, Vol. 102, No. 2 Table I. Descriptive statistics for each species at each locahty. Data given are mean, standard deviation, and sample size (in parentheses). L = locality; variable abbreviations are civen in te\t \ ariable L SH sw S LBW WBW WH W D T S.\ Mexipyrgus churinceanun 1 5.14 2.62 7.76 3.37 2.39 6.18 1.90 076 6.17 1.32 (15) 0.39 0.20 0.57 0.21 0.21 0.37 0.16 O07 0.49 O06 2 6.13 3.21 9.34 3.85 3.00 7.03 1.81 0.67 5.87 1.36 (15) 0.30 0.11 0.35 0.19 012 057 0.19 O04 0.53 O06 3 4.76 2.48 7.24 294 2.32 6.57 1.75 068 6.13 1.35 (15) 0.32 0.21 0 49 017 019 048 0.14 0.05 0.79 0.06 4 5.02 2.72 7.74 3.44 2.47 6.23 1.97 073 5.99 1.35 (14) 0.23 0.12 029 0.16 012 027 0.16 0.06 027 O07 5 3.99 2.17 6.16 2.60 2.02 6.28 1.98 068 6.19 l.'jl (15) 0.22 0.17 0.38 0.12 016 0.38 036 0.07 064 0.07 6 7.30 3.98 11.3 4.68 3.55 6.55 1.86 0.61 5.77 1.36 (14) 0.56 0.33 084 024 0.36 041 021 O04 067 0.04 7 6.48 3.17 9.66 4.13 2.88 7.28 2.05 O70 6,67 1.36 (15) 0.30 0.18 041 0.24 0.24 044 0.40 0.07 0,65 006 8 5.49 2.54 8.03 3.. 57 2.24 7.03 1.92 0.73 7,13 1.41 (15) 0.18 0.14 025 014 0.09 061 0.28 0.06 087 0 06 9 7.16 3.62 lO.S 4.39 3.45 6.58 1.76 O70 6,44 1.41 (15) 0.46 0.22 0.66 019 026 0.32 0.10 O07 0.73 O09 Mcxithaiima quadri \i(iludiuiu 1 7.39 6.44 13.8 6.61 4.72 4.57 2,20 0.62 3,81 1.11 (15) 0.55 0.41 0.90 047 O30 0.24 022 0.05 044 0.06 2 5.82 5.07 109 5.09 3.64 4.47 2.26 O60 3.14 1.13 (15) 0.41 0.28 0.66 042 0.24 0.23 0.32 0.04 0.40 0,06 3 5.73 4.83 106 5.04 3.54 4.63 2,28 065 3.50 1.13 (15) 0.30 0.33 0.59 031 019 0.25 0.33 0.05 O60 0.06 4 6.20 5.45 11.7 5.45 3.99 4.37 2.05 062 .3..52 1.07 (13) 0.57 0.36 087 0.58 025 0.26 021 0.06 0.60 0.08 5 5.77 5.09 109 5.14 3.68 4.19 2.36 0.61 3..38 1,12 (9) 0.61 0.55 1.12 052 041 0.11 041 0.08 048 0,05 6 6.72 6.00 12,7 5.76 4.51 4.44 2,07 061 3,34 1,03 (9) 0.60 0.49 1,07 047 047 041 0.11 0 05 048 0,0.5 7 5.23 4.50 9.73 4.56 3.27 4.32 2.14 0.63 2,85 1,12 (15) 0.36 022 0.55 0.34 0.20 0.26 0.19 0.04 0.21 ()()5 8 6.07 5.15 11.2 5.18 3.78 4.67 2.20 062 .3.17 ! 10 (15) 0.48 0.30 0,72 042 0.25 029 0.25 0.07 0.37 0,06 9 6.40 5.51 11,9 5.47 4.15 4.63 2.16 0.64 3.51 1.08 (15) 0.44 029 067 0,35 0.27 0.30 0.19 004 056 O05 S'yinphophiltis minckleyi 1 6.66 5.30 12.0 .5.19 4.00 4.80 2.06 057 3.24 1.12 (15) 0.38 019 0.53 0.28 0.20 034 037 O03 0.29 0.05 2 5.99 4.56 10.6 4.51 3.76 5.03 1.88 059 3.82 1.09 (15) 0.47 031 073 034 0.22 O09 019 O05 0.43 0,03 3 5.12 4.09 9.21 3.96 3.15 4.54 2.01 0.57 3.35 1 10 (12) 0.43 0.26 067 0.31 0.20 0.37 026 0.03 0.36 004 4 5.88 4.89 10.8 4.50 3.79 5.39 1.89 054 3.32 1.05 (7) 0.39 015 042 0.25 0.09 0.35 012 0.02 033 004 5 5.56 4.34 9.90 4.38 3.48 5.28 2.08 0.60 3.60 1.14 (15) 0.34 0.23 0.50 0.28 0.19 0.38 0.29 0,03 048 0.03 6 7.17 5.98 1.3.1 5.29 4.84 5.68 1.86 054 3,19 1,13 (15) 0.30 0.26 0.45 0.24 018 0.26 0.16 0.04 042 0.05 R. Hershler and L.-A. C. Havek, 1988 Page 59 Tabic I. Oititiimcd Variable L SH SW S LBW WBW W'H W D T SA t .5.69 4.53 10.2 4.13 .3.74 5.22 1.76 0.58 3.45 1.07 til) 0.29 0.27 0 54 0.19 0.26 0.14 0.04 0,05 0.24 0.05 8 7.03 5.55 12.6 5.32 4.35 .5.23 1.88 0.57 3.34 1.18 (10) 0.25 0.36 0.55 0.28 0.27 0.18 0.29 0.04 0.35 0.07 9 7.48 5.85 13.3 5.61 4.61 5.47 1.83 0.59 3.21 1.17 (15) 0.46 0 30 0-6S 0.35 0..30 0.27 0.13 0 06 0.32 006 species unless very significant heterogeneity of variance existed, in which case the generahzed Welch test was used to consider mean differences. Pearson correlations were computed across species pairs for population means of each variable. Principal component analysis (PCA) was applied separately to each species data matri.x to assess and compare groupings of specimens without a priori assumptions. Because the units of measurement were distinct and non-comparable, the anaKses were performed on correlation matrices. Discriminant anal\ sis (DA) was used to determine assignment of specimens to the locality groupings on basis of shell size and shape. This anal\ sis w as computed in a stepwise manner in order to identify measurements contributing to significance of discrimination. Selection criterion was ma.ximization of Mahalanobis D-squared between closest pairs of locali- ties. The a posteriori procedure of classification analysis yvas performed to determine possible error of specimen assignment to locality . When SL and SW yvere replaced by their sum (S), slightly better localit) separation re- sulted in the multivariate analyses and these results are reported. Computations yvere performed using SYSTAT (Wil- kinson, 1986) on an IBM-.XT. and SPSSX Ver. 2 on an IBM 4381 VM/CMS system at the Smithsonian Institu- tion. prevalent among iV. minckleyi populations and partic- ularly pronounced for those of Mexithaiima quadripa- ludium. For each of the three species, only three principal components y\ere significant and y ielded meaningful in- formation. Eigenstructuresshoyv that the first component in each analysis is dominated by size and size-correlated variables (table 3), and explains 39-46% of the total vari- ation. For Mcxipyrguschitrinceaniis, tyvo shape variables (T, SA) dominate the second component yvhich explains almost 20% additional variability, and a sixth variable (W) is the sole measure of importance on the third axis, explaining 14%. For the other tyvo species, size (PCI) explains 10% more variation than for Mexipyrgus chu- rincearms, yvhereas shape (PC2 and 3) explains only slightly less. Weights for shape parameters are spread over both the second and third axes, making interpre- tations of these more difficult. Figure 4, consisting of plots of the first three PC's for each species with locality means (centroids) indicated, alloyvs comparison of relative locations of populations in PC space among species. Spread of centroids is largely along PCI, as expected. Each plot has one or ty\o tight clusters of a feyv centroids, w ith cluster segregation more RESULTS Descriptive summary statistics for each species by lo- cality are in table 1. Results of locality tests for both mean differences and variance are in table 2. Hetero- geneity- of variance yvas more pronounced for Mexipyr- gus churinceanus (significant for six variables at P < 0.01 level) than for the other species. Inter-locality vari- ation was marked for each species, and in ail but three cases (LB\\', Mexipyrgus churinceanus; W, D, Mexi- thauma quadripaludium ) the hy pothesis of mean equal- ity of variables across localities was rejected at 0.05 level. As an example, inter-locality variation in the size-indi- cator variable, S (= SH -I- SW). is shoy\ n in figure 3, yvith significant differences (P < 0.05) indicated by non-over- lapped confidence intervals. Size range for each species is considerable; significant differences (i.e., absence of overlap in figure 3) are especially numerous among pop- ulations of Mexipyrgus churinceanus, y\ ith overlap more Table 2. Results of .\iialysis of \ariance, or Welch's test; and Bartlett's tests for homogeneity of variance for the nine local- ities (**: P < 0.01; *: 0,01 < F < 0,05; ns: P > 0,05). \ ariable SH SW S LBW WBWWH W D T SA Mexipyrgus churinceanus Mean ** ** ** ns \ari- ance ns * ** * Mexilhaiima quadripaludium Mean ** ** ** ** Vari- ance ns ns ns ns Symphophihis minckleyi Mean ** ** ** ** X'ari- ance ns ns ns ii'- ** ** ** ** ** *♦ ns ns ns ** ** ns ns ' ns ' ns ** ** ** ** ** ** * ** * Page 60 THE NAUTILUS, Vol. 102, No. 2 12 - 10 E E CO 6 - Mexipyrgus c h u rincean us _i 1 I ; L. 1 3 5 7 9 Mexith a u m a qiiadripalu din m 14 - E 12 ♦ 10 1 10 1 \ < i 14 E E 12 10 - 13 5 7 9 Ny m phop h ilu s ni in c k leyi _j I { I I I 13 5 7 9 LOCALITY obvious for Mexipyrgus churinceanus and xV. minckleyi than for Mexithauma quadripaludium. Results of discriniiiiant aiiaK ses on looalit\ are in table 4. Size (S) is the most hea\ il\ weighted \ariable on DFl for Mexithauma quadripaludium and \. minckleyi, with LBW weighting negatively; while LBW and S are ap- [)ro.\imatel\ ec)ual!\ and positiveK weighted on this tuiiction for Mexipyrgus churinceanus. .\s \s itli the prin- cipal components anaKsis, the Brst discriminant axis ex- plained almost lO^c more variation for Mexipyrgus chu- rinceanus than for the other two species. Note that the shape parameters W and D were not correlated \\ ith any of the functions for any of the species. Entry of the first variable (S) alone for Mexipyrgus churinceanus \ielded significant (P < 0.01) separation of mean values for all but a single locality pair (1, 4). While entr\ of four additional \ariables significantK sep- arated this final pair (P < O.O.j), the significance level decreased to 0.082 after addition of all remaining vari- ables. Entr\ of the first \ariable for Mexithauma quad- ripaludium (WBW ) and \. minckleyi (S) resulted in significant .separation of all but eight and fi\e pairs, re- spectiveK; further addition of remaining \ariables left four and one pairs still unseparated. Classification error rates for indi\idual specimens in- dicated considerable overlap of populations, and varied across localities as follows: Mexipyrgus churinceanus, 53-100?c correct classification [87/c (overall)]; Mexithau- nm quadripaludium. 40-87rc [62rc (overall)]; A', minck- leyi. 60-100'7 [84^t (overall)]. Mexithauma quadripa- ludium was the poorest classified overall. \\ ith less than 60% classification in five of nine localities. Only three discriminant functions were significant for this species {P < 0.05), compared to six for the other two. .additional anaKses using onK shape parameters yielded consider- ably poorer classification [ranging from 26-39'^c (overall) for each species], and confirmed the low discriminating power of these variables (see Hershler & Sada, 1987). Differentiation among drainage systems was also ex- amined. The study area encompasses tour local drainages (as recognized b\ LaBount\. 1974, with localities allo- cated to these as follows (following notes in Appendix): Becerra System (Localit> 1 ); El Garabatal (2-4); Rio Mes- quites S\stem (5-8); and Tio Candido System (9). Clus- tering of populations in PC-space (figure 4) does not closeK follow partitioning of localities into drainages, as imlicated b\ considerable spread of centroids represent- ing localities from El Garabatal i2-4), and from the inter- connected springs at Los Remojos (6-8). For further analysis, localities were re-grouped into drainage systems. .\ di,scriminant anaKsis on each species Figure 3. Piols of S (Sll + S\V) vs. locality for each species. Filled circles represent medians; and bars denote simultaneous confidence intervals around the median, con.structed so that if parentheses do not overlap, population medians are different at 95% confidence level. R. Hershler and L.-A. C. Havek, 1988 Page 61 Table 3. Results of Principal Compoiit'iits .\iial\scs on cacli species. Only factor coefficients having weights > 0,25 are listed. I = Mexipyrgus churinceanus, 11 = Mcxilhauina quadripalndium. Ill = Nijmphophihts inincklcyi, Kig. = eigenvalue; % V. = % of variance explained. I 11 III PCI PC2 PCS PCI PC2 PC3 PCI PC2 PC3 s 0.30 0.30 0.28 LBW 0.30 0.30 0.27 WBW 0.29 0.30 0.27 r 0.55 0 44 -0.45 SA 0.44 0.43 0.59 0.36 0.31 w -0.77 0.55 0.69 D 0.43 -0.64 0 60 VVH -0.32 -0.37 -0.32 Eig. 3.22 1.51 1.10 3,19 1.22 1.00 3.49 1.35 1.11 % V, .39 2 19.8 13.8 45.5 17.4 144 45 6 16.9 13,9 using ail \ariables \\ as able to separate the four drainage groups only for Mexipyrgus churinceanus: only two functions were signiBcant for the other species. Resuhs of these analyses are in table 5. Note the low weights of S on DFl for Mexithauma quadripalndium and N. minckleyi compared to these for Mexipyrgus churin- ceanus, and the relatively small amount (ca. 40%) of variation explained by the first function for all three species. Classification error rates for individual specimens were similar for the three species: Mexipyrgus churin- ceanus, 61-93% [68% (overall)]; Mexithauma Cjuadri- paludium, 46-93% [60% (overall)]; N. niinckleyi, .57- 100% [77% (overall)], with highest classification for Drainage 1 (87-100%) and lowest for Drainage 3 (46- 61%). There is similarity of pattern of size variation for the three species: populations having large-sized shells are concentrated in the southeastern portion of the study area (figure 3, Localities 6-9). For standard shell mea- surements, population means were significantly corre- lated for Mexipyrgus churinceanus and Nymphophilus minckleyi (r > 0.61, P < 0.05 for S, SL, SW, WBW) and Mexithauma quadripalndium with Nymphophilus minckleyi (r > 0.60, P < 0.05 for S, SL, SW, WBW, LBW). There were no significant correlations between Mexipyrgus churinceanus and Mexithauma quadripa- ludium. Population means for whorl number and shape parameters were not correlated across species with one exception (Mexithauma quadripalndium with Nympho- philus minckleyi, r = 0.64, P < 0.05 for W). Table 4. Results of Discriminant AnaKses on locality for each species. Standardized function coefficients (> 0.25) and pooled within group correlation coefficients (> 0.25) of each function with each original variable are listed. 1 = Mexipyrgus churinceanus; II = Mexithauma quadripalndium; III = Nymphophilus minckleyi; Eig. = eigenvalue; % V. = % of variance explained; C.C. = canonical correlation 1 II III DFl DF2 DF3 DFl DF2 DF3 DFl DF2 DF3 Standardized coefficients s 0.64 0.89 0,94 -0.66 1,51 -1.61 LBW 0.69 0.90 -0.95 -0.56 1.88 2.02 -1.09 -1.43 1.63 WBW -0.35 -1.13 0.56 -0.94 -2.15 0.35 0.91 D T 0.39 0.65 0.30 SA 0.34 WH 0 49 0.61 0.79 0.48 0.77 Eig. 13.3 2.19 0.61 3.13 0.56 0.45 8.95 2.61 0.56 % V. 79.2 13.0 3.6 70.9 12.7 10.1 69.3 20.2 4.3 C.C. 0.96 0.83 0.62 0.87 Correlation 0.60 coefficients 0.56 0.95 0.85 0.60 s 0.89 -0.38 0.88 0.31 0.84 -0.36 LBW 0.94 0.74 0.54 0.61 -0.53 0.38 WBW 0.64 -0.65 0.93 0.83 T 0.34 0.31 SA 0.46 0.34 WH 0.72 0,77 0.30 0.38 0,78 Page 62 THE NAUTILUS, Vol. 102, No. 2 0 1 J Mexipyrgus churiiiceanus Mexithauma quadripaludium (5)@ 3 ® Nymphophilus minckleyi Despite these correlations, concordance of pattern among plots of PC scores for the three species is not impressive, although there is similarit) in order along size-related PCI (figure 4). Note that the tightest clus- tered centroids for Mexipyrgus churinceanus (Localities 1, 3, 4) are vvideK separated for the other two species. SiniilarK . di\ t-rgeiit "outK iiig centroids lor gi\en sf>ecies {Mcxithaiinia quaclripaludium, I, S. minckleyi, 3) are not so differentiated in the other species. As mentioned abo\e, the populations of Mexipyrgus considered in this stud\ are referable to four nominal species (fide Ta\ lor. 196(-)) on basis of shell sculpture and color banding; Mexipyrgus churinceanus (Localities 1, 2, 4); Mexipyrgus rnojarralis (5); Mexipyrgus lugoi (6- S); and Mexipyrgus carranzae (9) (the form present at Localit) 3 is distiiicti\e and not clearK referable to any nominal species). These nominal species are poorly seg- regated on the PC axes: extent of separation of rnojarralis (5) and carranzae (9) from other centroids, for instance, is exceeded by that seen among three populations refer- able to churinceanus in Los Remojos spring complex (6- 8). DISCUSSION For all three species, most inter-population variation in- volved shell size and size-correlated variables. Common- ality of geographic variation patterns was indicated by significant correlation of population means tor some of these variables across two of three species pairs. The extent of this commonality was not, however, impressive when groupings of populations based on multivariate anal) ses were examined. A strong correlation between geographic variation pat- terns and current drainage configurations was not ap- parent for any of the species, suggesting that in this example development of intraspecific di\ersit\ of shell inorphometrv ma\ be related to ecological as well as historical factors (see Chernoff, 19S2, for general dis- cussion of this subject), although we acknowledge the possibilitv that the poor correlation w ith current drainage configuration ma\ be obscured b\ historicalK complex basin hydrograpln (Miiickle\, 19(i9; Hershler \ Minck- ley, 1985). Springpools concentrated around the northern tip of Sierra de San Marcos (where the study area is located) are higliK unilorm in water quality (Miiickley in Cole, 1968): single measurements taken b\ us during the study indicated, for instance, that temperature and conductivity ranged among the nine springpools from 25.5-34.5 °C (seven localities diftering b\- < 4 °C) and 1,825-3,500 micromhos cm (seven localities differing by < 430 micromhos, cm), respectively. Pools do dilter con- Figure 4. 'rliree-dimeii.sioiial plots ot PC cenlroids for the three species t\ axis. PCI; Y, PC2; Z. PC:.'3). standardized and viewed in perspective. Sizes of balls indicating centroids are scaled to heighten perspective. R. Hershler and L.-A. C. Hayek, 1988 Page 63 Table 5. Results of four-group Discriminant Analyses on drainage system for each species. Standardized function coefficients (> 0.25) and pooled within group correlation coefficients ( > 0.25) of each function with each original variable are listed. I = Mexipyrgus churinceanus: II = Mexithauma quadripaludiutn; III = \'ymphophilus minckleiji; Eig. = eigenvalue; % V. = % of variance explained; ('.C. = canonical correlation I 11 III DFl DF2 DF3 DFl DF2 DF3 DFl DF2 DF3 Standardized coefficients s 2.28 0.72 2.39 -0.49 2.11 0.84 0.87 1.76 -2.78 LBW -2.5.3 0.71 1.43 -3.12 -0.46 1.41 -1.49 1.35 WBW 1.05 -0.98 -1.87 1.23 -0.91 -1.50 1.71 W 0.61 D 0.52 -0.46 0.66 0..57 -0.67 T 0.55 0.87 SA 0.38 0.42 0.67 WH -0.36 -0.63 0.51 0.53 Eig. 3.21 1.51 1.10 3.24 1.26 1.03 3.49 1.35 1.11 % V. 40.2 18.8 13.8 40.4 15.8 12.9 43.6 16.9 1.3.9 c.c. 0.642 0.499 0.431 0,710 Correlation 0.426 coefficients 0.262 0744 0.717 0.217 s 0.58 0..55 0.89 0.32 0.49 0.63 LBW 0.48 0.58 0.96 0.61 0.57 \VB\\' 0.65 0.36 0.80 0..50 0.83 VV 0.61 D -0.36 0..59 -0.50 T 0.47 0.40 0.68 -0.33 SA 0 31 -0..32 0,46 WH (144 -0.47 0,31 0.48 0,68 siderablv in other potentially important parameters such as size, substrate composition, and abundance of mol- luscivorous cichlid fishes and the relationship between these features and shell geographic variation merits fur- ther study . Groupings of populations of Mexipyrgus churinceanus on basis of shell size and shape were not strongly con- cordant \\ith allocation of these to nominal species de- fined b\ shell color banding pattern differences. Fur- thermore, both univariate and multivariate analyses showed that these populations were no more differen- tiated in terms of shell size and shape than were those of seemingK monomorphic Xymphophilus winckleyi. These results suggest that evolution within Mexipyrgus has been mosaic, with development of striking diversity in shell color banding patterns and a few other features (including aspects of shell sculpture, and penial lobation pattern) coupled w ith unremarkable divergence in shell morphology. It is intriguing that these snails and A', minckleyi. which differ greatly in microhabitat and presumed po- tential for gene flow between populations at spring sources, have similar levels of intraspecific shell morphometric divergence, whereas Mexithauma quadripaludiutn. which broadly- overlaps in niche with the latter (Hershler, 1984), is less variable. The possibility that these patterns reflect differing times of origin of lineages within the basin is not currently testable due to absence of fossil evidence. ACKNOWLEDGEMENTS Fieldwork was supported by Smithsonian Research Op- portunities Fund #1233F650. .Assistance in the field was pro\ ided by Dr. W. L. Minckley , Dr. P. Marsh, A. Riggs, and C. Riggs. The assistance of staff of the Scanning Electron Microscopy Laboratory at NMNH in photo- graphing shells is gratefully acknowledged. Ms. Molly Kelly Ryan, staff illustrator of the Department of Inver- tebrate Zoology (NMNH), generously prepared figures on very short notice. Paul Greenhall (NMNH-IZ) per- formed the laborious task of gathering shell morpho- metric data. Drs. M. G. Harasewy ch, R. Dillon, and an anonymous reviewer provided useful criticism of the manuscript. LITERATURE CITED Chapman, R. E., M. G. Harasewych, and R. Hershler 1988. CONCH: an interactive computer program for the analysis of shell coiling parameters. In preparation. Chernoff. B. 1982. Character variation among populations and the analysis of biogeography, American Zoologist 22: 425-439. Cole. G. A. 1984. Crustacea from the bolson of Cuatro Cie- negas, Coahuila. Mexico. Journal of the .\rizona-Nevada .\cademy of Science 19:3-12. Endler, J. .\. 1977. Geographic variation, speciation, and dines. Princeton University Press, \J, ix -t- 246 p. Gould, S. J. and R. F, Johnston. 1972. Geographic variation. .\nnual Review of Ecology and Systematics 3:457-498. Page 64 THE NAUTILUS, Vol. 102, No. 2 Hershler, R. 1984. The h\(lrobiid snails (Gastropoda: Risso- acea) of the (^uatro C^ienegas Hasin: systematic relation- ships and ecology of a unique fauna. Journal of the .Ari- zona-Nevada .-Keademy of Science 19:61-76 Hershler, R. 1985. Systematic revision of the Hydrobiidae (Gastropoda: Rissoacea) of the Cuatro Cienegas Basin. Coahuila, Mexico. Malacologia 26:31-123. Hershler, R. and VV. L. Minckley. 1986. Microgeographic variation in the banded spring snail (Hydrobiidae: Mexi- pyrgits) from the (;uatro Caenegas Basin. (;()ahuila. Mex- ico. Malacologia 27:357-374. Hershler, R and U VV. Sada. 1987. Springsnails (.Gastropoda: Hydrobiidae) of Ash Meadows, .•\margosa Basin, Califor- nia-Nevada. Proceedings of the Biological Society of Washington 100:776-843. Kohn. A. J. and A. C. Riggs. 1975. Morphometry of the Conus shell. Systematic Zoology 24:346-359 LaBounty. J. F. 1974. Materials for the revision of cichlids from northern Mexico and southern Texas. LS.\ (Pcrci- formes: (^ichlidae). Ph.D. thesis (unpublished), Arizona State University. Tempe. 120 p. McCoy, C. J. 1984. Ecological and zoogeographical relation- ships of amphibians and reptiles of the Cuatro Cienegas Basin. Journal of the .'Vrizona-Nevada Academy of Science 19:49-59 Minckley, V\' L. 1969. Environments of the bolson of Cuatro Cienega.s. Coahuila, Mexico L'niversity of Texas at El Paso. Science Series Number 2, p. 1-65. Minckley, W. L. 1984. Cuatro Cienegas fishes: research re- \ iew and a local test of diversity versus habitat size. Journal of the Arizona-Nevada Academy of Science 19:1.3-21. Minckley, VV. L. and G. A. Cole. 1968. Preliminary limnologic information on waters of the Cuatro Cienegas Basin, Coa- huila. Mexico. Southwestern Naturalist 13:421-431 Haup. D. M 1966. Geometric analx sis ot shell coiling. Journal of Paleontology 40:1178-1190.' Taylor. D. VV. 1966. A remarkable snail fauna Irom Coahuila, Mexico. Veliger 9:152-228. Taylor, D. VV. and W. L. Minckley. 1966. Neu world for biologists. Pacific Discovery 19:18-22. Wilkinson, L. 1986. SYSTAT:' the system for statistics. SYS- T.-VT, Inc., Evanston, IL. APPENDIX Springpools sampled are numbered as in figure 1. Lo- cality names are either those of Minckley (1969) or reflect local usage. Locality data represent air distances troni Cuatro Cienegas. Dates of collection are given in paren- theses. Catalog numbers (USNM) for voucher material (dry shell plus alcohol specimens) from each locality are given in follow ing order: Symphophihis ininrklciji Tay- lor, Mcxipyrgiis cliiirinrcaiuis Ta\ lor, ami Mcxithauiua quadripaluilium Taylor. 1. Poso de la Becerra [(south pool) 3-1X-86], 13.7 km W-SW of C^uatro C^ienegas. A once enormous spring area (over a kilometer long) signilicantK reduced in size hy canal development in early 19605 (see Taylor, 1966:162; Minckley 1969: figs. 15, 16). Currently consisting of two large springpools (each ca. 50 x 125 m-) connected by short section ot stream. Spring orifices few and large, occurring in tleepest (to 7 ni) portion of pools. Water liK stands extcnsi\ c Spring and outflow i-onstituting a major drainage of basin now feeding canals. USNM 857909, 857918, 857927. Sites 2-4 represent three springs in the area known as El Garabatal, located north of Poso de la Becerra and east of Becerra s outflow . El Garabatal drains to the north and west, and may be considered either a separate, small drainage or a subset of the Rio Mesquites system, the largest drainage in the basin. 2. Laguiias de Juan .Santos (5-IX-86), 12.8 km W-SW ot Ciuatro Cienegas. Largest of El Garabatal springs con- sisting of series of relatively shallow (depths to 2.0 m), inter-connected lagunas fed by springs emerging along pool margins. Pool area somewhat larger than that of Poso de la Becerra. Extensive marshes bordering near- entirety of spring's perimeter. Water lily stands exten- sive. Stream outflow extending several hundred meters before terminating in shallow marshv area. USNM 857912, 857921, 857930. 3. Unnamed small spring, know n to biologists working in area as North Spring (3-IX-86), 12.0 km W-SW of Cuatro Cienegas. Small springpool ca. 12 x 18 m. about a meter deep, w ith ca. 20^ coverage b\ water lily . Out- flow entering second pool (not a spring); di.scharge from latter e.vtending 50 m before disappearing into hole. USNM 857910, 857919, 857928. 4. Unnamed large spring (.5-IX-86), 11.8 km W-SW ot Cuatro Cienegas. Roughly circular springpool, ca. 70 m across; depths not exceeding 3.5 m. Water lily dense in center of pool. Outflow feeding small marsh. USNM 857916, 857925, 857934. 5. "West" Laguna in El Mojarral (4-I\-86). 9.0 km SW of Cuatro Cienegas. Moderate-sized spring (26 x 59 ni; Arnold, 1972:12), with depths to 4.5 m. Orifices few in number, cavernous. Water lily stands few, relatively thin. Water exiting spring \ia both a shallow, surficial stream and single, tubular, subsurface \ent. Stream out- flow entering "East Laguna, which in turn drains into Rio Mesquites. USNM 857908, 857917, 857926. Sites 6-8 are inter-coiuiected springpools known lo- cally as Los Remojos. 9.0 km S-SW ot Cuatro Cienegas. Site 6 drains into a large pool recei\ ing discharge from a second pool fed by outflows from Sites 7 and 8. System draining into Rio Mesquites. 6. Northernmost of Los Remojos springs (5-IX-86). Pool ca. IS X 32 m. Depths generalK > 1.5 m; water lily common. USNM 857913, 857922,' 857931. 7. Intermediate Los Remojos spring (5-IX-86). Pool ca. 28 X 47 m. shallow (< 1.0 m). Water lib uncommon. USNM S57914. 857923. 857932, 8. Southeriunost of Los Remojos springs (5-IX-86). Pool moderately large (22 x 42 m), with depths increasing in southern end of pool to 4.0 m. Water lib common. USNM 857915, 857924, 857933. 9. Laguna Tio (-andido (5-IX-86), 12.5 km S-SW of C.uatro Cienegas. Large spring (ca. 45 x 100 m) exten- sively vegetated by water lily and other macrophytes. Depths generally from 2.0-4.0 m. Outflow extending eastward, comprising part of a major system positioned south of Rio Mesquites drainage. USNM 85791 1, 857920, 857929. THE NAUTILUS 102(2):65-72, 1988 Page 65 Niche Congruency of Freshwater Gastropods in Central North America with Respect to Six Water Chemistry Parameters Eva Pip Department of Biology University of Winnipeg Winnipeg, Manitoba R.3B 2E9 Canada ABSTRACT Occurrences of freshwater gastropods were studied at 430 sites in central North America with respect to total alkahnity, total dissolved solids, chloride, sulphate, phosphorus, and dissolved organic matter. Mean niche positions for the gastropods were calculated for the six combined water chemistr\ parameters by comparing mean values for each species using agglomerative hierarchical cluster analysis. Total niche relations were exam- ined by calculatmg and summing the amount of overlap in the observed ecological tolerance ranges for the six parameters for each species pair, and appKing cluster and principal compo- nent anaKses. The results showed that the species occupied a broad spectrum of niches, with progressively increasing eco- logical range. Gastropods with low mean inorganic values and narrow niche widths were interpreted as specialists for waters with low concentrations of dissolved inorganic materials. Species which clustered together in terms of central tendencies of oc- currence often differed from each other in terms of overall niche similarity, and vice versa. Competition may have been more important in waters with low inorganic concentrations. INTRODUCTION A number of workers have demonstrated the importance of water chemistry in the distribution of freshwater gas- tropods {e.g.. Boycott, 1936; Hubendick, 1947; Aho, 1966; Harman & Berg, 1971; Dussart, 1976; Pip, 1978, 1985, 1986; Okland, 1979; Okland & Okland, 1980). However, aside from the pioneering study of Finnish lakes by Aho et al. (1981). relatively little is known regarding niche relationships between freshwater gastropod species that coexist within a given geographical area. The ecological niche of a species can be described as an infinite h) perspace representing ail physical and biot- ic aspects of the environment in which the species occurs. Nevertheless, practical considerations restrict most niche studies to a few selected parameters that are thought to be important for the species (Levins, 1968 in Aho et al., 1981). .According to the latter v\orker, the niche of a species with respect to a given parameter can be ap- proximated by observing the species distribution over a range of values of the parameter in a number of envi- ronments. The objective of the present study was to examine niche relationships for the freshwater gastropods in cen- tral North America in six water chemistry dimensions: total alkalinity, total dissolved solids, chloride, sulphate, moly bdenum reactive phosphorus, and dissolved organic matter (DOM). These factors were chosen because a pre- vious study (Pip, 1987) showed that these variables con- tribute towards variation in species richness of freshwater gastropod communities within the study area. In the present study a niche was defined as the range between the minimum and maximum values observed for each species in the study area, and was thus analogous to the concept of the "realized niche" discussed bv Hutchinson (1957). MATERIALS AND METHODS A total of 430 sites was examined in central North Amer- ica (47°-54°N and 94°-106°W) during the May-Septem- ber, 1972-85 seasons. All sites contained water year-round. Ponds (< 10 ha) comprised 41.0% of the sites sampled, lakes (> 10 ha) 41.5%, rivers (> 2 m deep) 10.3%, and creeks (< 2 m deep) 7.2%. Each site was examined for snails by wading or canoeing; snails on macrophytes were obtained by dredging with a rake or by using SCUBA. Search time at each site was limited to 1 hr. Surface water samples were collected at most sites, but at depths of >3 m where macrophytes did not reach the surface a van Dorn sainpler was used. The samples were placed on ice in darkness and frozen within a maximum of 48 hr. Samples were analyzed using methods rec- ommended b\ the American Public Health Association (1971). While most of the sites were sampled only once, ap- proximately 50 of the locations were resampled at dif- ferent times of the growing season and in different \ ears. For such sites, extreme low and high water chemistry values were used for statistical anaKses. Because of en- vironmental heterogeneity , large lakes were sampled at different locations which were treated as separate sites. Mean and niche comparisons were made using ag- glomerative hierarchical cluster analysis (Sneath & Sokal, Page 66 THE NAUTILUS, Vol. 102, No. 2 1973). Ward's method, a minimum variance technique (Wishart, 1969) was used for clustering. Cluster fusion distances were calculated by means oi the squared Eu- clidean distance measure: Distance,, = S, (Xj — y,)- Because Ward's method is an intense!} clustering pro- cedure, ranking of the species in the dendrograms was checked for misclassifications by comparing with the ranking obtained using the unweighted pair-group meth- od (Cliltortl k Stephenson, 1975), a weakly clustering strateg) (Sneath & Sokal, 1973). The two methods showed similar relative ranking; thus mi.sclassifications were not apparent. Since the relative importance of the six pa- rameters differed with species and situation (Pip, 1987), ail parameters were weighted etiualK in the cluster anal- yses. In construction of the dendrogram for mean niche position (tigure 1), mean values for each of the six pa- rameters were used to construct a data matrix for the comparison of taxa with respect to the mean positions of their niches. Because of differences in units and statistical distributions of the six chemical parameters, values were converteil to standardized Z scores, each parameter w ith a mean of 0 and a standard deviation of 1. Ward s method was applied to the Z scores. The first step in niche comparison was the construction ot a combined niche congruenc\ matrix for the six chem- ical parameters. For each parameter, the amount of o\er- lap in the observed ecological ranges of each species pair was di\ided by the combined range of the two species (range between lowest minimum and highest maximum values). Parameter \alues were not standardized. The six overlap proportions were then summed for each species pair (maximum possible value 6.0). The combined coef- ficients formed a niche congruency matrix that was ana- i\ zed using cluster anaKsis as above to gi\e the dendro- gram in figure 2. The niche congruency matrix was also examined using principal component analysis (Tatsuoka, 1971), based on the error correlation matrix. Components were f)rthog- onalK rotated so that the lirsl principal component lay along the direction of greatest variance. Statistical programs used for dendrogram construction and principal component analysis were obtained from SPSS. Inc.. (Chicago. Illinois. RESULTS The ranges of concentrations of the inorganic chemical parameters encompassed at the stud\ sites have been presented elsewhere (Pip, 1986). The inorganic param- eters showed a number of significant (P < 0.05) positive intercorrelations at the stud\ sites (table 1) and could therefore be regarded as a block with main similar trends. However DOVl was significantK correlated onK with moK bdenum reactive phosphorus and total dissoK ed sol- ids. Five or more sets of w ater chemistr\ data were avail- able for 36 species in the present stud\ (table 2); only these species were included in cluster and principal com- ponent analyses. The bulk of the mean, maximum, and minimum values on w hicli anahses were based are gi\en by Pip (1986) for all parameters except DOM, which is given in table 2. The dendrogram for mean niche positions (figure 1) with respect to the six combined parameters reflected the lf)cations in the ecological ranges w here each species w as most often found. C^lnster 1 consisted of species w ith the lowest mean values lor total dissolved solids and low values for all other inorganic parameters. On the other hand, Armiger crista, Physa jcnncssi. and Fossaria mo- dicella differed the most frcmi all other species; these gastropods showed the highest mean values for total dis- solved solids, as well as high \alues for all other param- eters (Pip, 1986), including DOM. Other species in the spectrum could show low or high \alues of DOM which were largely unrelated to the concentrations ot inorganic parameters; for example Valvata tricarinata, Fossaria decampi. and Stagnicola catascopium show ed the lowest mean values for DOM ol all species except Campcloma decisum (table 2). The relations between species in terms ot niche con- gruency for the six parameters are represented by the dendrogram in figure 2. The groups that emerged formed a spectrum ol the ranges of chemical environments in which each species was observed. Clusters 1 and 2 con- sisted of species that showed narrow tolerance ranges for Table 1. Correlations between water chemistrv parameters at the stud\ sites Upper diaRonal = r. lower diaijonal = p. \ = 446- 468. \lii|\ Ixlemini Disso!\e 2 S5 - — Q. » ^ O o K O 3 ■~ w •» © CO O E >»•»—«»- .. jr o 3 o "^ < CL U- < ll- O •o ° o K !: ^ 2 o C^ O- 3 o£ «)^- e c ; « O 0>« c =^ I I — I — I — I — I — I — r-~T — I — E<» E o o = °- ° - — C 3 Si? E c a. o° > -o ■ Z <« — o O O" w — O U J o o c = >. ! ' — JO O E o E « < I Q. Q. > *rt o> 0»£» ■~ «« <> o .1- c o o o o.E >^ » E U- to CO Q. u. 2 o O X < - o c o o 15 •> e ? Q. o o 3 i ^5 ? °-t o -o • I- •» o E ° o ^ u Eo o „ — 6o « o o — c E " s |l 1 1 — e — — Q O O 3 V -^ X O CD I CO UJ !b (L u c u. „ !b U- O ^ UJ o iH n. o , c z S_Q o 1 en 3j O 3 l' ^ ^ rt c: O -jT) :t1 tJD ^ 0^ M C U 0) Q o s a 01 -=. Page 68 THE NAUTILUS, Vol. 102, No. 2 — •» O fl) > ■5 R ? * > — o •- il c >> m f o o t » O T3 crista anceps ypnorum rina us exacuo tricarinata « !S o E o a caperat parva a compes us umbilic o 3 X c o — o ._ « >, o a> o 1 o o • »- o o c 0-5 3 E c o - o •> t a. o i S • o S E J tloma decisu onia decepta ma corpulent icola reflexa 0> m 3 3 c >^ o — 3 O f O o o 3 -j; o IS °:h o o o »2 O O o 3 3 o e C O o «* o ^^ o >^ c V) !! o 2 i." O O c c O n c E (/> (/> ^ .- 3 c u 2 X (/) >v >« ° E 2 S ° 2 o "i ° w o o »- c 0) ^ — «. 3 E o o < X < Q. Q. > Q. < en li. a. 0. u. 1 (/) U. Q. b u_ u_> X m < u u ^ U n - o ^ I- z Ul u o o z o to 3 CO • o o o L O o 2 — It ^-^ "" a; *- c c a; ■5.§ II sic 5 c o o ^ 60 C _3 U o — t E .2? S E. Pip, 1988 Page 69 the inorganic parameters at low corieeMitratioiis (Pip, 1986), The narrow tolerance ranges ot these species con- tributed towards larger interspecific differences, as seen from the larger cluster fusion coefficients; niche overlap with species that had broad ranges was small, while the probability that significant proportions of the niches of any two species w ith restricted ranges would not coincide was increased b) the narrowness of the respective ranges. As a result, relative niche differentiation was better de- fined in waters with low inorganic concentrations. Species witii broader ecological tolerance ranges, on the other iiand, could occur in waters with high inorganic concentrations, although in most cases they could also tolerate comparatively low values. These species formed the clusters on the upper part of the dendrogram in figure 2, and were more numerous than species which were restricted to a narrow range of environments. The greater similarity between members of each of these clusters derived from the larger degree of overlap that necessarily arose as a result of the broad ranges. Cluster 6, composed of Stagnicola paliistris, Fossaria modicella, and Physa jennessi, represents species that occurred in the broadest range of chemical environments. Niche relations were also examined using principal component anal\ sis applied to the niche congruency error matrix, which extracted two major components that ac- counted for 55.4% and 22.7% of the variance, respec- tively. The remaining components each accounted for 5% or less of the remaining variance. The niche relations for individual species are plotted with respect to the first two principal components in figure 3. The distributions that emerged reflected the groupings of figure 2, al- though clusters 1 and 2 from figure 2 showed close af- finities (groups A and B) in figure 3. Species in groups A and B showed narrow niche widths and low mean parameter values. Species in groups E and particularly F showed wide ecological ranges; these groups also in- cluded the most common species in the stud\ area (Pip, 1978). The first principal component of the niche congruence- error matrix was significantly correlated w ith mean val- ues for the respective species of all six parameters (total alkalinity r = 0.49, P = 0.001; total dissolved solids, phosphorus, and chloride, all r = 0.47, P = 0.002; sul- phate r = 0.36, P = 0.016; DOM r = 0.33, P = 0.023; all N = 36). This large number of correlations derived from intercorrelations of these parameters at the sites examined (table 1). The strong correlations with the first component are interesting, in that the values in the orig- inal congruency matrix were not themselves correlated with any of the chemical parameters. The second prin- cipal component showed no significant correlations with the mean values of the parameters examined and was apparentl) related to an unmonitored factor. DISCUSSION Cluster analysis showed that the gastropods within the study area occupied a broad spectrum ot chemical niches. Table 2. Mean, maximum, and minimum values of dissolved organic matter (absorbance of acidified water at 27.5 nm) ob- served for the gastropods in the study area. Mini- Maxi- Species X mom mum \ Campeloma clecisum (Say, 1816) 0.142 0.060 0.200 6 Valvata sincera Say, 1824 0.313 0.106 0.737 7 V. Iricarinala (Say, 1817) 0.204 0.018 1.366 70 Cincinnatia cincinnatiensis ^Anthony, 1840) 0.210 0,054 1.366 42 Marstonia decepta (Baker, 1928) 0.209 0.0.53 0.665 8 Probythinella laciislris (Baker, 1928) 0.299 0.180 0.387 8 Amnicola limosa (Say, 1817) 0.263 0.039 1.428 102 A. walkeri Piisbry, 1898 0.212 0054 0,815 23 Lymnaea stagnalit Linne, 1758 0.325 0.018 1.676 285 Bulimnea megasoma (Sa\-, 1824) 0.356 0054 1,383 45 Stagnicola palustris MuUer, 1774 0.314 0.060 1.638 182 S. catascopium (Say. 1817) 0.169 0.053 0.395 13 S. caperata (Sa\-, 1829) 0.349 0.252 0.438 6 S. reflexa (Say, 1821) 0.311 0.130 1.089 7 Fossaria decampi (Streng, 1896) 0.167 0.060 0.366 9 F. exigua (Lea, 1841) 0.266 0,030 0.817 15 F. modicella (Say, 1825) 0.345 0.039 1.400 53 F. parva (Lea, 1841) 0.244 0.095 0.392 6 Phijsa gyrina Say, 1821 0.307 0.009 1.638 293 P. jennessi skinneri Tavlor, 1953 0.387 0.042 1,306 33 Aplexa hypnonim (Linne, 1748) 0.442 0.0.53 1,638 41 Ferrissia parallela (Haldeman, 1841) 0.426 0,115 0,815 6 F. ricularis (Say, 1817) 0.315 0,054 1,168 53 Helisoma trivolcis (Say, 1816) 0.341 0.018 1,968 207 H. pilsbryi infracarinatum Baker, 1932 0.254 0.050 0.684 23 H. corpulentum (Say, 1824) 0.214 0.173 0.263 5 H campanula! urn (Say, 1821) 0.237 0.009 0.817 109 H. anceps (Menke, 1830) 0.280 0.009 1.512 122 Planorbula armigera (Sa\-, 1821) 0.435 0,088 1.638 73 P. campestris (Dawson, 1875) 0.385 0,140 0,650 7 Promenetus exacuous (Sav, 1821) 0.324 0,053 1.428 84 P. umbilicatelliis (Cockerel!, 1887) 0.240 0.053 0.625 i Armiger crista (Linne, 1758) 0.483 0.364 0.815 17 Cyrauhis parvus (Say, 1817) 0.345 0.030 1.676 193 G. circumstriatus (Trvon, 1866) 0.347 0.053 1.428 27 C. deflect us (Say. 1824) 0 273 0054 1 428 70 In general, the species groupings in terms of niche sim- ilarity formed a continuous series with progressively greater ecological range. The niches of most species over- lapped to some extent, and only a few were mutually Page 70 THE NAUTILUS, Vol. 102, No. 2 PC I '55.4% ,i.«''9 33 3 7 2l\3S\ '24 Z. •-.<^ /24" 'if PC 2- 22.7% -1,0. — . — . — .- '10 '•^ 1 • . 114 \ , 5 •x . ^- 1,' - - 36/ I •23 s I I 12\D l»16" ."/ 18 25l_ »I.O •32 ^ •30 / "^!13/ /c •27; -1.0 Figure 3. Distribution of species plotted « ith respect to the first two principal components of the niche congruenc\ error matrix, .^.ves have been orthogonally rotated. Numbers repre- sent the following species: 1 — Campeloma decisum, 2 — Va/- vata sincera. 3 — V. tricarinata. 4 — Cincinnatia cincinnatien- sis, o — Marstonia decepta. 6 — Prolnjthinella lacustris. 7 — Amnicola limom. 8 — A. walkeh. 9 — Lymnaea stagnalis, 10 — Bulimnea megasoma, 11 — Stagnicola palustris. 12 — S. cata- scopium, 13 — S. caperaia, 1-4 — S. reflexa, 15 — Fossaria decam- pi, 16 — F. exigtia, 17 — F. modicella. 18 — F. parva. 19 — Physa gyrina, 20 — P. jennessi, 21 — Aplexa hypnorum. 22 — Ferrissia parallela. 23 — F. riciilaris, 24 — Ilclisoma trivolvis, 25 — H. pihbryi infracarinatum, 26 — H. corpulentum, 27 — H. cani- panulatum, 28 — H. anceps. 29 — Planorbula armigera, 30 — F. campestris. 31 — Promenetus exaciwus, 32 — F. umbilicatellus, 33 — .Armigpr crista. 34 — Cyraulus parvus, 35 — G. circtim- striatus. 36 — G. deflectus. e.xclusive for some parameters. Thus, with respect to the variables e.xamined, the majority of the species studied could theoretically occur together in the same eri\ iron- meiit, near the lower end of the concentration scale for inorganic parameters. For example 25 of the species could occur through the entire range of 100-200 mg liter for total dissolved solids, and an additional eight could occur in jiortions thereof (Pip, 1986). .Mean niche positions may be regarded as the types of environments for which each species was most charac- teristic. Stagnicola reflexa. Helisorna corpulentum. Bu- limnea megasoma. Campeloma decisun}. //. campan- ulatum. Amnicola walkeri. and Marstonia decepta were classified in clusters 1 and 2 in both figures 1 and 2. These species showed low mean values for inorganic concen- trations and narrow tolerance ranges; they may be re- garded as specialists for environments with low values of these factors. Since the latter environments in the study area are most common on the Precambrian Shield, it is not surprising that these species are also limited to, or most frequent in. Shield waters. It is interesting that some species showed marked dif- ferences in terms of their relative positions in the den- drograms when mean niche positions and niche con- gruencies were compared. For e.xample Lymnaea stagnalis. Stagnicola palustris. Cyraulus deflectus. and Helisoma anceps showed wide niches, but their central tendencies of occurrence were much more moderate. Indeed G. deflectus tended to occur most often at the low end of its ecological range, perhaps because it does not compete w ell w ith the nimierous other species which frequent higher inorganic concentrations. Species with similar mean niche positions, contained in the same clusters in figure 1, would be expected to compete with each other more frequently than with species in neighboring clusters, because they would be likely to occur in the same water bodies more often. Thus, although each species occupies a unique ecological niche (Hutchinson, 1957), the clusters of adaptively sim- ilar species could be viewed as functional groups (e.g., Stanley, 1979) which, on average, respond to certain aspects of the environment in similar ways. However, species w ithin the same clusters in figure 1 often showed differences in niche congruency in figure 2. For example, the species comprising cluster 2 in figure 1 show ed similar mean niche positions located at lower inorganic concen- trations, but of these species, Marstonia decepta was included in cluster 1 in figure 2, Ferrissia rivularis and Cincinnatia cincinnatiensis in cluster 3, Helisoma pih- bryi infracarinatum in cluster 4, and Cyraulus deflectus in cluster 5. Such differences in the ecological ranges of species w ith similar central tendencies of occurrence may ha\e been ad\antageous in that the reduced o\erlap al- le\ iated competition (e.g.. Hughes, 1980). since the pro- portion of cases where the tw o species would not be able to occur together was increased. The most common species in the study area [i.e.. Physa gyrina (6I.9'~( of sites sampled), Lymnaea stagnalis (60.7'( ). Helisoma trivolvis (45.3%), Stagnicola palustris (40.5%), Cyraulus parvus (39.5%)] (Pip, 19S7) showed broad tolerance ranges for the variables examined, and can occupy a wide xariety of habitats. These species would be expected to compete w ith each other frequent- ly, since large portions of their niches were congruent. However, they occurred most commonly at different mean positions w ithin their niches. Ot these five species, w hicli clustered in two adjacent groups in terms of niche congruenc) (figure 2), onl\ L. stagnalis and H. trivolvis occurred in the same cluster in terms of mean niche position (figure 1). Nonetheless, because ot the large amoimt of overlap, species with similar niches and broad ranges still often coexisted in the same water bodies. For example, the five most common species above were significantly associated w ith each other in the stuck area (Pip, 1978). Such species with large proportions ot niche oxerlap may minimize competition where they coexist by partitioning the hab- itat. For example G. parvus, a small species, feeds pri- mariK on periphy ton, w hile the larger of the common species also ingest macrophyte tissue, and ma\ favor E. Pip, 1988 Page 71 separate macrophyte species within the same water bod\ (Pip & Stewart, 1976). Interspecific differences in diet have also been reported by Reavell (1980). Other types of habitat partitioning may occur in certain situations, for example with respect to depth (Lacoursiere ct al., 1975), temperature (Boag, 1981), and turbulence (Calow, 1973). The proportionally greater niche differences between species found at low inorganic concentrations were re- flected b\ the lack of significant association between the species in clusters 1 and 2 in figure 2 at the same sites within the study area [e.xcept for M. decepta and H. campanulatum (Pip, 1978)]. Greater niche differences in unproducti\e environments ma\' have been associated with more intense competition (Emlen, 1973) than in nutrient-rich situations, where niches among many species were similar, and a number of interspecific associations were observed. Eutrophic waters show greater produc- tivity of algae and macroph\ tes, w hich constitute much of the food of freshwater gastropods (Reavell, 1980). Food has been proposed as an important factor regulating gastropod abundance and distribution [e.g., Dillon & Benfield, 1982). Species richness of gastropod commu- nities in the study area is positiveK correlated with tro- phic state (Pip, 1987). This correlation derives from the tendencies of many species to occur more often at higher values of phosphorus (Pip, 1978, 1986), despite the ob- servation that most of the species can also tolerate low- values of this factor. Competition has been put forward as an important factor governing gastropod distribution (e.g., Lassen, 197.5). Species which are taxonomically and morpholog- ically similar {i.e., "sibling species") (Aho et al., 1981) often were not grouped within the same clusters with respect to niche similarity (e.g., the species of each Stag- nicola, Fossaria, Helisorna) (figures 2 and 3), indicating intrageneric ecological differentiation, w hile other con- geners (Gyraulus circumstriatus and G. deflectus) were grouped together. Aho et al. (1981) found a similar lack of consistency in the distributions of gastropods in Fin- nish lakes and suggested that competition is only one of a number of factors that contribute towards distribution. Conversely, most of the groupings w hich emerged in figures 2 and 3 contained a wide representation of dif- ferent taxonomic and morphological entities. Accord- ingly, while the niches within each group were similar with respect to the parameters examined, species behav- ior and ecological requirements were likeK to be differ- ent, decreasing competition. Furthermore, differences with respect to other parameters ma\ also have been important, for example t\ pe of water bod\ and bottom substrate (Pip, 1986), t\pe of vegetation (Pip, 1978), or other, unmonitored, chemical and physical variables. Principal component analysis yielded a representation of the species in a hyperspace, of w hich the first two dimensions accounted for more than three-quarters of the variance. While the first dimension was clearly re- lated to the types of chemical environments in which the species most often occurred, the groupings in figure 3 also reflected the geographical distributions and types of habitats frequented by the respective species. Species in groups A and B were present largely in Precambrian Shield w aters characterized by low total dissolved solids, and were absent or rare west of the Shield boundary. Species in group C frequented ponds and small lakes (Pip, 1986) with intermediate water chemistry values. Group D occurred frequently in lakes. Group E species occurred in a very w ide variety of water chemistry types, and differed w ith respect to preferences for water body type, in some cases lacking discernable preferences en- tirely. Species in group F occurred in the most extreme ranges of water chemistry, but were found most fre- quently in ponds (Pip, 1986). While the niche means and widths utilized here are those observed for the study area as a whole, ecological ranges may vary for a given species in different geo- graphical regions (Pip, 198.5), and are likeh different for individual populations. The importance of particular pa- rameters ma\ also vary among habitats with different chemical and physical characteristics (Pip, 1987). Thus the exact position of the niche may be a plastic attribute that can vary to some extent with situation as well as time. LITERATURE CITED Aho, J. 1966. Ecological basis of the distribution of the littoral freshwater molluscs in the vicinity of Tampere, South Fin- land. Annales Zoological Fennici 3:287-322. Aho, J, E. Ranta, and J. Vuorinen. 1981. Species composition of freshwater snail communities in lakes of southern and western Finland. Annales Zoological Fennici 18:2.33-241. American Public Health Association. 1971. Standard methods for the examination of water and wastewater. American Public Health .Association, New York, 874 p. Boag, D. .\. 1981. Differential depth distribution among freshwater pulmonale snails subjected to cold tempera- tures. Canadian Journal of Zoology 59:733-737. Boycott, C. 1936. The habitats of the freshwater molfuscs in Britain. Journal of Animal Ecology 5:118-186. Calow, P. 1973. Gastropod associations w ithin Malham Tarn, Yorkshire. Freshwater Biology 3:521-534. Clifford, H. T. and VV. Stephenson. 1975. An introduction to numerical classification. Academic Press, New York, 229 p. Dillon, R. T., Jr. and E. F. Benfield. 1982. Distributions of pulmonate snails in the New River of Virginia and North Carolina, U.S.A.: interaction between alkalinity and stream drainage area. Freshwater Biology 12:179-186. Dussart, G. B. J. 1976. The ecology of freshwater molluscs in north west England in relation to water themistry. Journal of Molluscan Studies 42:181-198. Emlen, J. M. 1973. Ecology: an evolutionarx approach. .\d- dison- Wesley Co., Reading, \i.\, 493 p. Harman, W. N. and C. O. 15erg. 1971. The freshwater snails of central New York with illustrated ke\s to the genera and species. Search: Cornell L niversit\ Agricultural Ex- perimental Station 1:1-68. Hubendick, B. 1947. Die Verbreitungsverhaltnisse der lim- nischen Gastropoden in Sudschweden. Zoologische Bid- rucke Uppsaliense 24:419-.559. Hughes, R. N. 1980. Strategies for survival of aquatic organ- Page 72 THE NAUTILUS, Vol. 102, No. 2 isms. In: Barnes, R. S. K. and K. H. Mann (eds.). Funda- mentals of aquatic ecosystems. Blackwell Scientific Pub- lications, Oxford, p. 162-184. Hutchinson, G. E. 19.57. Concluding remarks. C^old Spring Harbor Sym[X)sium. Quantitative Biology 22-41.5-427 Lacoursiere, E., G N'aiiiancourt, and R. Goiilure 1975. Re- lation entre les plantes aquatiques et les gasteropodes (Mol- lusca. Gastropoda) dans la region de la centrale nucleaire Gentilly 1 (Quebec). Canadian Journal of Zoology 53:1868- 1874. Lassen, H. H. 1975. The diversity of freshwater snails in view of the equilibrium theory of island biogeography. Oeco- logia 19:1-8. Okland, J. 1979. Distribution of en\ ironmental factors and fresh-water snails (Gastropoda) in .Norway: use of Euro- pean invertebrate surve\ principles Malacologia 18:211- 222. Okland, J. and k. A. Okland. 1980. Acidification threatens trout diet. Research in Norway 1980, p. 21-27. Pip, E. 1978. A survey of the ecolog\ and composition of submerged aquatic snail-plant communities, Canadian Journal of Zoology 56:2263-2279. Pip, E. 1985. The ecolog\ 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. Nautilus 100:56-66. Pip. E. 1987. Species richness of freshwater gastropod com- munities in central North America Journal of MoUuscan Studies 53:16.3-170. Pip, E. and J M Stewart. 1976 The dynamics of two aquatic plant-snail associations. Canadian Journal of Zoolog\ 54: 1192-1205. Reavell, P. E. 1980. A study of the diets of some British freshwater gastropods. Journal of Conchology 30:253-271. Sneath, P. H. A. and R. R. Sokal. 1973. Numerical taxonomy. \V. H. Freeman and Co., San Francisco, 573 p. Stanley. S. M. 1979. Macroevolution, pattern and process. VV. H. Freeman and Co., San Francisco, 332 p. Tatsuoka. M. M. 1971. Multivariate analysis: techniques for educational and psychological research. John \\ ile\ & Sons, New York, 310 p.' Wishart. D. 1969. Mode analysis: a generalization of nearest neighbour which reduces chaining effects. In: Cole, .\. J. (ed). Numerical taxonomy. Academic Press, London, p. 282-308. THE NAUTILUS 102(2):73-77, 1988 Page 73 Factors Affecting the Distribution of Sphaeriid Bivalves in Britannia Bay of the Ottawa River B. \^ . Kilgour G. L. Mackie Departmt'iit of Zoology Universit) of Guelph Guelpli, Ontario NIG 2W1 Canada ABSTRACT Distribution of Sphaeriidae in Britannia Bay of the Ottawa River was not homogeneous and was primarily affected by sediment particle size and depth. Total sphaeriid diversity is maximal at particle sizes near 0.18 mm. Total sphaeriid density and abundance of the genus Pisidiurn increase with decreasing water depth. Distribution of species within the genera Pisidiurn and Musculium is variable. These data indicate that compar- isons of pisidiid distribution should consider at least depth, and particle size in the sampling design. INTRODUCTION The importance of sphaeriids as part of the aquatic com- munity has lead to a number of studies dealing with the distributional patterns of this group (Healey , 1978; Mack- ie et ai. 1980). Most studies, liowever, ha\e dealt with distribution patterns among a group of lakes, rivers, or sections of a river. Usually it is assumed that variation among sites is greater than the variation within sites. However, data in Avolizi (1976) and Holopainen (1979) suggest that the abundance of some species can be vari- able within a single site, but little work has been done to determine the extent of this variation. Britannia Bay , a section of the Ottawa River just above Ottawa and Hull, Canada, is relatively unpolluted, and is known to contain a diverse sphaeriid fauna ( 15 species), including members of Musculium. Pisidiurn, and Sphaerium (Mackie, 1971). The purpose of this study was to determine if the depth distribution of sphaeriids in Britannia Bay is homogeneous, and if distribution is a function of the sediment particle size, organic matter content, algal biomass, and depth. MATERIALS AND METHODS During mid-.\ugust. 1985. benthos and sediment samples were taken at eight depths (0.25. 0.35, 0.50, 1.0, 2.0, 3.0. 4.0, and 6.0 m) along a transect in Britannia Bay of the Ottawa Ri\er (figure 1). At each depth, five Ekman grab (15 x 15 cm, 0.32 mm mesh screen on top) samples were taken, except at 0.36 m where four samples were taken. A sediment sam- ple was taken at each depth from which three subsamples (approximately 100 ml) were taken. Two for determi- nation of percent organic matter content and one for geometric mean particle size. From each benthic sample, all sphaeriids and algae (entangled masses of Lyngbya sp. and Vaucheria sp.) were hand picked. Sphaeriids were counted and iden- tified to species. Algae was dried at 70 °C and weighed to the nearest 1.0 mg. Total sphaeriid diversity (Shannon & Weaver, 1949) and density (N/m-), and individual species abundances were calculated for each benthic sample. The organic content of the sediments was estimated by ashing two of the sediment samples from each depth and expressing the result as percent loss on ignition. Geo- metric mean particle size was determined with the third sediment sample from each depth using the methods outlined by Lotspeitch and Everest (1981). Stepwise multiple regressions (Ostle & Mansing, 1975) were performed to determine which environmental fac- tors significantly affected total sphaeriid diversity and density, and the abundances of individual genera and species. Only those variables found to be independent by simple correlations (table 1), were used coincidentally in the regression models. Box plots (McNeil, 1977) determined that all data, except diversity values, were most normally distributed when the depth means were transformed by logjQ. All simple correlations and stepwise multiple regressions were calculated using the normalized data. RESULTS Depth means of algal biomass, and ?? organic matter content are presented in figures 2 and 3. Both parameters increased with increasing water depth. Trends in sedi- ment particle size are given in figure 4. Compared to other depths, sediments were coarser at the 1.0, 2.0. and 6.0 m depths. Twelve sphaeriid species were found in Britannia Bay Page 74 THE NAUTILUS, Vol. 102, No. 2 laoa- Figure 1. Map of the Ottawa River, and an enlarged map of Britannia Bay above Ottawa indicating location of tfie transect. Depth contours on enlarged map are in metres. with P. casertanum the most abundant species. Mean abundances at each depth for each species are presented in table 2. Diversit) values were highest at the shallow depths (0.2.5-0.50 in) and at .'3.0 and 4.0 m (figure 5). Stepwise multiple regression indicated that diversity increased with decreasing particle size (table 3). Figure 6 indicates a unimodal distribution oi diversity in relation to geo- metric mean particle size. Maximum diversilN occurred near a particle size of 0.18 mm. Regression analysis indicated that total sphaeriid den- sity significantly increased w ith decreasing water depth Table I. C^nrrelatinns between some environmental variables. Sigiiilitant rorrclaliniis [P < O.O.'j) are indicated 1)\ asterisks (•) .Mgal biomass Organic matter Depth Organic matter Depth Particle size 0.787* 0.839* f) Vyl 0.863* -0,043 80D- <00- o.so 1.0 2.a Depth (in) «.0 6.0 Figure 2. Mean algal biomass at each depth along the transect with 95^< confidence limits indicated b\ vertical lines. (table 3). Density at 0.25 m was less than that at 0.36 and 0.5 m (figure 7). Abundance of the genus Fisidium significantK in- creased w ith decreasing water depth (table 3). A similar relationship was found for P. variabile. Abundance of P. casertanum significantK increased with finer sediments and lower organic matter content. None of the other seven Pisidium species were correlated with the en\i- ronmental variables. Abundance of the genus Musculiniu did imt correlate with any of the variables tested, .\bundance ot A/, trans- versum increased significantK with decreasing water depth (table 3). Abundance of A/, secitris correlated pos- itively with algal biomass. No relationship was found tor the genus Sphaerium which was represented b\ onK one species, S. striati- nuin. at 2- 0 322 0.25 0.36 0.50 1.0 2.0 3.0 t. 0 6.0 Depth (m) Figure 3. Mean organic matter content of the sediments at each depth along the transect with 95^t confidence limits in- dicated l>\ \frtital lines. B. W. Kilgour and G. L. Mackie, 1988 Page 75 Figure 4. Geometric mean particle size at each depth along the transect. 2.5- 1.5- 0.50 l.D Depth (m) 6.0 Figure 5. Mean diversity values at each depth along the tran- sect with 95^0 confidence limits indicated bv vertical lines. DISCUSSION In Britannia Bay, total sphaeriid diversity significantK- in- creases with finer sediments. The finer sediments at 3.0 and 4.0 m, which correspond with high diversity values, contradict the positive correlation which exists between particle size and depth in rivers (Hamill, 1975). The sand bar between the 3.0 and 4.0 m sites (figure 1) may have affected the distribution of sediments in the same manner that P'olke and Ward (1957) describe for a sand bar in the Brazos River. The unimodal distribution of diversity in relation to particle size (figure 6) indicates that diversity is maximal at a particle size near 0.18 mm, and decreases with finer or coarser material. Finer substrates enhance burrowing (Rogers, 1976), production (Hamill, 1975), growth and reproduction (Mackie & Qadri, 1978), and may improve survival in young clams (Gale, 1976). Fine substrates, however, may reduce oxygen a\ailability (Meier-Brook, 1969; Hartnoll, 1983). The particle size at which diversity is maximized may represent the optimal grain size for efficient burrowing and /or oxygen/ nutrient availability'. Total sphaeriid density increases in shallow water in Britannia Bay. From the literature, it appears that re- source availability and utilization may be affected by depth. Bacteria and phytoplankton (especially diatoms), which are food resources for sphaeriids (Holopainen, 1985), are generally more abundant in shallow water (0- 2.0 m) than in deep water (> 5.0 m) (Hargrave, 1970). The drop in total sphaeriid density at 0.25 m which Table 2. Mean abundance (No. /m-) of individual species at each depth along the transect. Depth (m) Total no. Species 0.25 0,36 0.5 1.0 2.0 3,0 4.0 6.0 sampled Musculium M. securis (Prime, 18.32) 17.8 0 8.9 0 88.9 80.0 115.5 35.6 39 M. transversum (Say, 1829) 444.4 266.6 26.6 8.9 17.8 0 0 0 80 Pisiditim P. casertatuim (Poli, 1795) 942.1 1,833.2 1,173.2 35.6 17.8 142.2 106.7 0 437 P. duhitim (Sav, 1816) 17.8 11.1 26.7 0 8.9 0 8.9 0 8 P. fcrrugineum (Prime, 1852) 0 22.2 44.4 0 0 8.9 0 0 8 P. hcnsloivanum (Sheppard, 1825) 0 188.9 168.9 0 0 0 8.9 0 37 P. lilljeborgi (Esmark and Hoyer, 1886) 124.4 600.0 1,262.1 8.9 8.9 35,6 88.9 35.6 230 P. nitidiim (Jenvns, 1832) 231.1 944.4 1,528.7 0 0 17,8 26.7 26.7 291 P. punctatum (Sterki, 1895) 133.3 422.2 160.0 0 0 8.9 17.8 8.9 75 P. lahabile (Prime, 1852) 106.7 100.0 195,5 8.9 0 0 0 0 44 P. ualkcri (Sterki, 1895) 0 11.1 0 0 0 0 0 0 1 Sphacriuni S. striatiniim (i.amarck, 1818) 0 0 195.5 26.7 35,6 231.1 62.2 17.8 64 Total no. sampled 227 396 539 10 20 59 49 14 1,314 Page 76 THE NAUTILUS, Vol. 102, No. 2 2.5- .'-*-, 2- A \ 1.5- '' \ s,. 1- 1 1 ^'**«,«„,^^ .5- 5 1 .2 1 .25 . sooo- Geometric Mean Particle Size (mm) Figure 6. Relationship between mean diversity and geometric- mean particle size with 95/( confidence limits indicated b\ vertical lines. 4500- ^ 2500- i 200O- Of CD c 1500- o Of ^ 1000- 500- ^ 0. 50 1.0 2. 0 Depth (m) 3.0 4.0 6.0 Figure 7. Mean densits at each depth along the transect with 95% confidence limits indicated h\ vertical lines. is inconsistent with the regression model, ma\ result from wave action and or summer lethal temperatures, which can significantly reduce the numbers of sphaeriids in the shallower areas in Britannia Ba\ (Mackie, 1971; Mackie & Qadri, 1978). Regression analysis suggests that the genus Pisidium prefers shallower water in Britannia Bay. The relation- ship between P. variabile and depth is consistent with the distribution of the genus. In contrast, P. casertanum prefers finer substrates with lower organic matter con- tent. The distribution of P. casertanum suggests that there can be variabilitv in the distributional patterns of species within a genus. That the distribution of the genus Musciiltum is not related to an\ oi the variables tested may be due to variation in the distribution patterns of the two species of Musculiiim. Competition between M. securis and M. transversttni in Britannia Bay, as described b\ Mackie et al. (1978), ma\ also be responsible for these results. It is likely that two species are not sufficient to determine a general distribution pattern of a genus. Table 3. Significant relations between the dependent \ ariables (D) and the independent variables (I), where, R = correlation coefficient between 1) and I, a = algal biomass, b = depth, c = geometric mean particle size, and d = % organic matter content of the sediments Significance D I fi (D.I) level Total sphaeriid diversity c -0.791 P < 0.020 Total sphaeriid density b -0.720 P < 0.050 Musculiiuu scrtnis a as 19 P < 0.025 Mttsculinni trunsrcr^iun 1, -0 940 P < 0.010 I'isidiuni b -0.733 P < 0.030 Pisidium cascfidiniin c -0.711 d -0614 total R- = 0.883 P < 0 010 Pisidium vnhahilc 1. (19.39 P < OOIO The positive relationship between abundance of M. securis and algal biomass has also been described by Mackie and (^adri (1978) who suggested that M. securis utilizes the algae Lyngbya and Vaucheria as food re- sources in Britannia Ba\. The \ariabilit\ in the distri- bution of the two species of Musculium ma\ also be related to the food forms with which the clams are as- sociated. That the abundance of the genus Sphaeriuin and most Pisidium species do not correlate with the em ironmental variables ma\ be a result of modal relationships with these variables, or relationships with variables that were not tested. The relationships found centre on the im- portance of particle size and depth, w hich have been shown b\ Green ( 1971 ) to be important factors affecting distribution of sphaeriids among lakes. It is suggested that in studies dealing with the distribution of sphaeriids, particle size and depth are important factors to be con- sidered in the sampling design. ACKNOWLEDGEMENTS We wish to thank Mr. Clarence Kilgour for help with the sampling. Comments from Mr. Chris McCiall and two anonymous reviewers improved the manuscript. The study was funded b\' the Natural Sciences and Engi- neering Research Council of Canada, Grant No. A-9882 awarded to C; LM. LITERATURE CITED .\volizi, R J. 1976. Biomass turnover in populations of vivip- arous sphaeriid clams: comparisons of grow th. fecundity, mortalitv and liiomass production Hvdrobiologia 51: 163- 168. Folke, R. L and W C W ard 1957 Brazos River Bar: a study in the significance of grain size parameters. Journal of Sedimentary Petrology 27:3-26 Gale, W. F. 1976. \'ertical distribution and burrowing be- B. W. Kilgour and G. L. Mackie, 1988 Page 77 haviour of the fingernail clam, Sphaeriuni transvcrsum. Malacologia 9:121-125. Green, R. H. 1971. .\ multivariate statistical approach to the Hutchinsonian niche: bivalve molluscs of central Canada. Ecologv 52:543-556. Hamili. S. E. 1975. Production of sphaeriid clams and am- phipod crustaceans in the Ottawa River near Ottawa-Hull, Canada. M.Sc. thesis. University of Ottawa, 98 p. Hargrave, B. T. 1970. Distribution, growth, and seasonal abundance of Hyallela azteca (Amphipoda) in relation to sediment microflora. Journal of the Fisheries Research Board of Canada 27:685-699. Hartnoll, R. G. 1983. Substratum. In: Earll, R. and D. G. Erwin (eds. ). Sublittoral ecology: the ecologv of the sub- littoral benthos. Clarendon Press, 0.\ford, p. 97-124. Healey, M. C. 1978. Sphaeriid mollusc populations of eight lakes near Yellowknife, Northwest Territories. Canadian Naturalist 92:242-251. Holopainen, I. J. 1979. Population dynamics and production ol Pisiditim species (Bivalvia, Sphaeriidae) in the oligo- trophic and mesohumic lake Paajarvi, Southern Finland. Archiv fiir Hvdrobiologie 54iSuppl ):466-508. Holopainen, I. 1985 Feeding biology of Pisidiidae (Bivalvia) with special emphasis on functional morphologv of the digestive tract Lammi Notes 12:5-9. Lotspeitch, R. B and F. H Everest. 1981 A new method for reporting and interpreting te.xtural composition of spawn- ing gravel United States Forest Service Research Note PN\\-369. Mackie, G. L. 1971. Some aspects of the distributional ecology of macrobenthos in an industrialized portion of the Ottawa River near Ottawa and Hull, Canada M.Sc. thesis, Uni- versity of Ottawa, 161 p Mackie, G. L. and S. U. Qadri. 1978. Effects of substratum on growth and reproduction of Musculium securis (Bi- valvia: Sphaeriidae). The Nautilus 92:135-144. Mackie, G.L.S. U.Qadri, and R. M. Reed. 1978. Significance of litter size in Musculiuryi securis (Bivalvia: Sphaeriidae). Ecology 59:1069-1074. Mackie, G. L., D. S. White, T. W. Zdeba, and N. A. Thomas 1980. A guide to freshwater mollusks of the Laurentian Great Lakes with special emphasis on the genus Pisidium. U.S. Environmental Protection Agency, Duluth, MN, 144 p. McNeil, D. R. 1977. Interactive data analysis: a practical primer. John Wiley and Sons, Toronto, 186 p. Meier-Brook, C. 1969. Substrate relations in some Pisidium species (Eulamellibranchiata: Sphaeriidae). Malacologia 9: 121-125. Ostle, B. and R. W. Mansing. 1975. Statistics in research: basic concepts and techniques for research workers, 3rd ed. Iowa State University Press. Ames, 596 p. Rogers, G. E. 1976. Vertical burrowing and survival of sphae- riid clams under added substrates in Pool 19, Mississippi River. Iowa State Journal of Research 51:1-12. Shannon, C. E. and W. Weaver. 1949, The mathematical theory of communication. University of Illinois Press, Ur- bana, 125 p. THE NAUTILUS 102(2):78-81, 1988 Page 78 Hijpselostonia holimanae New Species, a Pupillid Land Snail from Thailand Fred G. Thompson Florida State Museum University of Florida Gainesvilie, FL .32611, USA Harry G. Lee 709 Lomax Street Jacksonville, FL 32204, USA ABSTRACT Hypselostorna holimanae new species (Gastropoda, Pulmonata, Pupillacea, X'ertiginidae) is described from a limestone range near Kancliaiiaburi. Thailand Its morphological characteristics are distinct to the extent that no close relationship between this form and other nicmbers of the genus is apparent. Hypselos- torna tubifcrum (Benson, 1856) from Burma is it closest phy- logenctic and geographic congener. The two species are alike in details ol sculpture and umbilical width, but differ widely in shell shape and aperture barriers. Similarities of reduced apertural dentition among other species of Hypselostorna are cnnsidered to be due to convergence. INTRODUCTION The land snail fauna of Thailand is \ery poorly known. The genus Hypselostorna is wideK distributed from Bur- ma through CJamhodia, Vietnam, Mala\a, the Loo C^hoo Islands and the Philippine Archipelago. Yet not a single species has hitherto been recorded from Thailand. The species de.scribed in this paper was collected by Stephen C. Holimaii while serving as a Peace Corps volunteer in Thailand. During his few opportunities of leisure, Mr. Holiman collected mollusk specimens for his mother, Mrs. Stanley (Bonnie) Holiman of Jacksonville, Florida, who has a.ssemhled a private collection of fair importance becau.se of the data that accompanies the specimens. The mollusks from Thailand were submitted to us by Mrs. Holiman for identification. The new species of Hypse- lostorna described in this paper shows strong similarity to the generic t\ pc species from Burma, and differs con- spicuously troi7i other known species. We are honored to name this snail after Mrs. Holiman in recognition of her bringing this species to our attention. Hypselostorna holimanae new species (figures 1-6) Description: Shell small, about 2.6-2.9 mm wide and 2.3-2.6 mm high; about 0.8.5-0.9.5 times as high as w ide. Shell turlMii-shaped with a moderateK long conical spire (figures l-.'3, holotype). Last whorl conspicuously en- larged, and with a distinct peripheral angle and a basal angle. Last whorl flat below peripheral angle, and strong- 1\ shouldered above. Occasional specimens may be weak- 1\ furrowed below periphery. Last whorl ascending at about 10° to longitudinal axis of spire (figures 2, 4). Neck of last w horl becoming narrowed behind aperture, and extending forward for about ',5 of minor diameter of last whorl (figure 3); indented externally over junction of angulo-parietal lamella and slightK so over colinnellar lamella. Base of shell broadK umbilicate due to lateral expansion of last whorl. Umbilicus about 0.40-0.53 times minor diameter of last w horl as measured across the basal angle. Whorls 4.6-4.9. Protoconch consisting of about 1.5 whorls that appear smooth under light microscopy; at higher magnifications the whorls are sculptured with a dense mesh of fine reticulating threads that have an underlying spiral arrangement (figure 5). Whorls of te- leoconch sculptured with raised spiral threads that are nearK uniformly distributed o\er the surface of the shell (figure 4). Threads weak liut distinct on spire; most con- spicuously developed on last whorl (figure 6). Spiral threads interrupted at irregular intervals b\ incremental growth striations, which in some specimens ma\' cause the spiral sculpture to appear cancellate or beaded on the spire. Color dark brow n with a light brow n aperture and white lamellae within the aperture. Face of aperture translucent w ith fine radiating lirow n lines due to raised spiral threads on opposite surface Peristome broadly ex- panded and nearK uniformly wide around aperture. Ap- erture barrier with four teeth located on inner rim of the aperture just behind expanding peristome and ar- ranged o|5posite each other in a cross-configuration. .An- gulo-parietal lamella rectilinear, torming a single short undulating blade; bifid as is typical for genus, with an- gular segment smaller and separated from parietal por- tion by a weak notch. Palatal and basal plicae short and lateralK llattcned; coiiliiied to inner ritu of peristome. Columellar lamella tubercular and located on a slight callus. Measurements in mm for the holot> pe and three para- t\ pes (I'F 1 13428) selected to show \ariation follow , The minor diameter is the transverse w idth of the bod\ w horl posterior to the neck of the aperture. Other measure- ments were made of standard parameters. F. G. Thompson and H. G. Lee, 1988 Page 79 1 Figures 1-6. Hypselostoma holimanae new species. 1-3. Holotvpe (UF 113427). x 26. 4-6. Parat\pe (UF 113483). 4. x 40. 5. X 120, 6. X 160. Page 80 THE NAITILUS, Vol. 102, No. 2 Specimen Height Maj. w. Min \v .\per w. L'mbil Whorls Holotype ■2A 2.6 2.4 1.4 1.2 4.7 Paratvpe 2.3 2.7 2.3 1.4 0.9 4.8 Paralype 2..3 2.6 2.3 1.2 1.0 4.6 Paralype 2.6 29 2.5 1.6 1.0 49 Type locality: Thuiluiid. Kaiicliaiiaburi Pro\ ince, small limestone range on the west border of the Kanchanaburi Agricultural College, about 15 km w est of Kanchanaburi. Holot\pe: IF 113427; collected March 15, 1987 b\ Ste- phen Holiman. Paratypes: UF 113428 (12), UF 113483, Mahidol Universit\ Malacology Collection, Bangkok (12), and the private collections of Harry G. Lee (12) and Bonnie Holiman (12). The specimens constituting the t\ pe series are recently dead shells. They were collected at the height of the dry season from leaf-litter in a forested knoll at the top of the limestone range. COMPARISONS Hijpselostoma Benson, 1 856 belongs to a group of genera that also includes Boysidia .\n\e\. 1881, Paraboijsidia Pilsbry, 1917, Gyliotrachela Tomlin, 1930, Aulacospira Moellendorff, 1890, Anauchen Pilsbry, 1917, and Sys- tenostoma Bava\ and Dautzenberg, 1909. These genera were monographed b\ Pilsbry (1917). More recently, Jutting (1950) reviewed the known species of the first four genera. Members of this group have protoconch sculpture similar to that described above for H. holi- manae. The variation of this sculpture w ithin the group and its ph\ logenetic significance v\ill be discussed else- where (Thompson, in preparation). The classification of species within these genera is sometimes problematic, and no one who has worked with the group seems to have been comfortable with the systematic arrangements of previous authors (Pilsbry, 1917; Jutting, 1950, 1961; Solem, 1981; Thompson & Dance, 1983). Much of the problem centers on the emphasis that is placed on the development of the parietal and angular lamella, the reduction ot the aperture barrier, the sculpture on the teleoconch and the degree to which the aperture is at- tached to or free of the previous whorl. Hypselostoma hohmanae is placed w ithin Hypselostoma because of the fused angulo-parietal lamella, the free aperture and the spiral sculpture ot the teleoconch. The angulo-parietal lamella is weaker than in most other species of the genus, and the aperture barrier in general approaches the con- dition that characterizes Anauchen. However, all of the species of Anauchen lack any indication of an angular lamella and none have raised spiral sculpture on the teleoconch. Few species of Hypselostoma have thus far been de- scribed from the mainland on southeast .\sia. Pilsbrv (1917) discussed the species known at that time. More recently. Jutting (1950) briefly reviewed the genus and described several additional species (1950, 1961, 1962). Hypselusluma. as used b\ both Pilsbrv and Jutting, is a poKpIn letic assemblage that contains species belonging to at least three genera. F"our species (H. terae Tomlin, 1939, H. megaphona Jutting, 1949, H. elaphis Jutting, 1949, // pcrigyra Jutting. 1949) were transferred to Boy- sidia (Dasypupa} b> Thompson and Dance (1983:109). Three others related to H. dayanum Stoliczka, 1871 be- long in another genus (Thompson, in preparation). The remaining species placed in Hypselostoma differ strikingK from //. holimanac. although H. tubiferum (Benson, 1856) from Burma appears to be the most closely related congener. It has a similarly broad umbilicus and similar spiral sculpture on the teleoconch, though not as strong. Because of these similarities the two species are considered to be more closeK related than either is to other known species w ithin the genus. The two differ in several conspicuous features. Hypselostoma tubiferum is much more depressed, the aperture is turned upw ard above the apex of the spire and the aperture barrier consists of 6-7 lamellar teeth (see Pilsbrv, 1917 for a description and illustrations). Hypselostoma holimanae differs from all other mainland species b\ its strong spiral sculpture, its reduced aperture barrier with tubercular columella lamella, its strong circumumbilical basal keel, and its broad umbilicus. Some Philippine species {H. sibuyanicum Moellendorff, 1896. H. quadrasi Moellen- dorft, 1896, H. roebeteni Moellendorff, 1894, and H. latispira Thompson and Auffenberg, 1984) are similar to H. holimanae in that the aperture barriers have been reduced to denticles, although they are not as weak as in //. holimanac. None has sculpture as strongK- devel- oped as //. holimanae. none has a basal keel circum- scribing the umbilicus, nor are any as widely umbilicate. Other differences that separate H. holimanae from these Philippine species are the shape of the shell and the contour of the whorls. Hypselostoma roebeleni and H. latispira are \er\ depressed species in which the up- turned aperture reaches almost to the level of the apex of the spire. Hypselostoma sibuyanicum and H. quadrasi have more slender shells w ith regularh increasing whorls, and both are narrovvlv rimate. The combination of all of these morphological differences indicate that the sim- ilar aperture barriers of the Philippine species and H. holimanae have evolved independentlv through tooth reduction from more comple.x ancestral conditions, and that no close relationship can be inferreil on the basis of these barriers. ACKNOWLEDGEMENTS We wish to thank Mrs. Stanley (Bonnie) Holiman for generously donating the holotvpe and part of the para- type series to the Morida State Museum and to Mahidol University. Stephen Holiman provided us with infor- mation about the type localitv. The illustrations com- prising figures 1-3 were rendered bv Ms. Wendy B. Zomlefer, Staff Illustrator, Florida State Museum. LITERATURE CITED Jutting, VV. S. S. van Bentliem 1950. The Malavan species of Boysidia. Paraboysidia, Hypselostoma, and Gyliotra- F. G. Thompson and H. G. Lee, 1988 Page 81 chela (Gastropoda. Pulnioiiata, Nertiginidae) with a cat- alogue of all the species hitherto described Bulletin of the Raffles Museum 21 5-47 Jutting, W S. S. van Benthem 1961. Additional new species and new localities of the family X'ertiginidae and the gen- era Oophana and Opisthostoma from Mala>a. Bulletin of the Raffles Museum 26:34-48, pis. 8-14. Jutting, W. S. S, van Benthem. 1962. Coquilles terrestres nouvelles de quelques collines calcaires du Cambodje et du Sud X'ietnani. Journal de Conchyliologie 102:3-15. Pilsbrv, Henr\ .\. 1916-18. Manual of conchology, Ser. II, 24. Pupillidae, Gastrocoptinae. Philadelphia, p. i-xii, 1- 380, pis. 1-49. Solem, A. 1981. Small land snails from Northern Australia, 1: species of Gtjiiotraclicia Tonilin, 1930 (Mollusca, Pul- monata, Nertiginidae). Journal ot the Malacological So- ciety of Australia 5:87-100 Thompson, F. G. and K. Auffenberg 1984. Hypselostoma latispira, a new pupillid land snail Irom the Philippine Islands. Proceedings, Biological Societv of Washington 97: 86-89. Thompson, Fred G. and S. Peter Dance 1983. Non-marine mollusks of Borneo, II. Pulmonata: Pupillidae, Clausili- idae. III. Prosobranchia: Hydrocenidae, Helicinidae Bul- letin Florida State Museum 29:101-152. THE NALTILL'S 102(2):82-87, 1988 Page 82 Eledone gaucha, a New Species of Eledonid Octopod (Cephalopoda: Octopodidae) from Southern Brazil Manuel Haimovici Dt-partamento de Oceaiiografia Fuiida^ao Universidadf de Rio Grande Cx. Postal 47-1, Rio Crande RS 96.200 Brazil ABSTRACT A lieu species of Eledone is described from tlie southwestern Atiaiitif at depths of 60 to 160 m, off Rio (Jrande do Sul, Brazil. The characters that distinguish this species from the other species of the genus are presented, as well as a morphometric com- parison with the sympatric Eledone massyae Voss, 1964. INTRODUCTION Several cephalopods were collected during a survey of the demersal resources of the inner shelf of Rio Grande do Sul between Solidao (30°40'S) and Chui (34°20'S) at depths to 100 m (figure 1) by the R/V "Atlantico Sul" of Funda^ao Universidade de Rio Grande (FURG). Hai- movici and Andriguetto (1986) stated that two species of the octopod genus Eledone were found. One of them, E. rnassijae, was described by \ oss (1964) and the second was a new species. Both sympatric species possess the generic character of papillae at the tips of the non- hectocot) iized arms of the males. Morphological analysis presented here as well as ijiochemicai dilferences fouml by Levi et al. (1985) separate these two similar species. MATERIALS AND METHODS All specimens studied were killed with fresh water, fixed in 10% formalin for 24 hr and preserved in 70% ethanol. Measurements were taken in millimeters, and all mea- surements and indices used are among tho.se described by Roper and Voss (1983). The drawings of £. gaucha are by Jose Angel Alvarez Perez. The types are deposited in the Museu Oceanografico de Rio Grande (MORG), Museu Nacional de Rio de Janeiro (MNRJ), Museu de Zoologia da L ni\ersidade de Sao Paulo (MZUSP), Museo Nacional de Historia Natural, Liruguay (MNHN), Museo de Ciencias Naturales de La Plata, Argentina (MCNLP), University of Miami Mollusks Laboratory (UMML) and National Museum ot Natural History, Smithsonian In- stitution (USNM). This work has been partially supported by a grant of the Conselho Nacional de Pesquisas Cientificas e Tec- nologicas (CNPq), Proc. 403293-83 and the surve\ fi- nanced bv the Comissao Interministerial de Recursos do Mar (CIRMj. Eledone gaucha new species (figures 2-14, table 1) Material examined: Holot\ pe; 6 32.5 mm ML, K \' Atlantico Sul, cruise 13/83, S'ta. 37, 32°58'S, 5ri9'W, 56 m, trawl, 17 Nov. 1983, MORG 23544. Parat\pes: 7 6 27-41 mm ML and 5 9 32-34 mm ML, R \' Atlantico Sul, cruise 13/83, Sta. 37, 32°58'S, 51°19'W, 56 m, trawl, MORG 23544; 2 <5 32-34 mm ML, R/\' Atlantico Sul, cruise 13/83, Sta. 39, 32°50'S, 50°45'W, 87 m, trawl, 18 Nov. 1983, MORG 23545: 1 S 21 mm ML. R \" Atlantico Sul, cruise 13/83, Sta. 2, 31°46'W, 100 m, 9 Nov. 1983, MORG 23846; 1 9 33 nun ML, R/\' Atlantico Sul, cruise 10/83, Sta. 51, 33°43'S, 52°13'W, 60 m, trawl. 29 Aug. 1983, MORG 23547; 4 9 28-33 mm ML, R/\' Atlantico Sul, cruise 10/83, Sta 57, 33°13'S, 51°25'\\'. trawl, 60 m, 30 Aug. 1983, MORG 23548; 1 2>3>4 in most specimens \\ ith dorsal arms markedly longer than others. All arms longer in males (except hec- tocotylized arm) than in females (ALl I to IV S: 273.2- 239.8-134.9-208.1; 9: 250.0-213.8-200.6-191.0). Suckers small, uniserial, well separated and deeply set into arms. Suckers somewhat crowded near tips of the arms on females. Two rows of minute fleshy papillae on all non-hectocotylized arms of males (figure 10). Number of suckers on basal half of the first right arms varies from 17 to 23 (ASC 6: 20.1; 9: 19.4), suckers slightly larger on all arms of males (lASI S: 7.7; 9; 6.5). Web extends over half the length of arms and de- creases from dorsal to ventral surface; web formula most trequentlv A:B:C:D:E. Web indices similar in both sexes; 24.4-24.1-21. 6-18.6-15.6 for males and 24.4-23.9-21.1- 18.3-14.9 for females. Third right arm in males hectocotylized (figure 9) (HcAI: 58.9). Ligula small (LLI: 8.8), without differen- tiated calimus (figure 9); spermatophore grove deep. Gill count in external hemibranch from 7 to 10, most trequentlv 8 in males and 9 in females (Gilc S: 8.2; 9: 8.9). Males reproductive system with no special figures (fig- ure 11). Penis long and tubular (PLI: 23.4) with a rather short diverticulum (PdLI: 7.8). Spermatophores undif- ferentiated (figure 13) from 12 to 20 mm (SpLI: 45; SpLWT: 1.56). Number of spermatophores in a sample of 40 mature males from 7 to 92 (mean 32.1). The proximal o\ iduct long, the oviductal glands small, the distal oviducts shorter and somewhat stouter (figure 12). Intraovaric eggs oval (figure 14); maximum lengths of apparently mature eggs approximately 8 mm. Num- ber of developing eggs in a sample of 42 maturing fe- males ranged 10-55 (mean 30.2). Buccal mass well developed, with small anterior sali- vary glands and larger posterior salivary glands. Esoph- agus connects to developed crop leading to muscular stomach and smaller spiral caecum united by two ducts to the large digestixe gland. Intestine thin and leads to the anus adjacent to ink sac opening. Ink sac superficialK embedded in the digestive gland (figure 7). Radula with a tricuspid rachidean tooth, three lateral teeth and a marginal plate (figure 8). Color of living animals changed from brow n to almost white dorsally always remaining clear ventrally. Color of specimens preserved in alcohol purplish gray dorsally and pale \ellow ventralK'. Inner surface of the arms, mouth, and ventral mantle with few chromatophores. 29° \^ 'vBRaSIL , ) M ^.\ J ^^ PORTO (N "sy ■*==5X5^«1-EGBE U J 30" 1 .320 V<^'.'/ V^ \: k (1 soLmAoy. 5^0 1 ")" '/ *'' 31° <^ r^ 32° >- tot ^J/ fGRANDE IJ K )^ / ' V, • / J^r^ /^ oi • ,,-— ' > oW/ !>l ■ 33° t / 7 ' • . -e- ARROIO CHuf^ ? '.■' o / •■. ■■ .■ • o 34° y --■■. Ci i -=-1 r — 1 — 1 — I 50t 50m 1 1 1 r __^ .00* 54° 53° 52° 51° 50° Figure 1. Sample localities of Eledone gaucha new species. Type locality: 32°58'S, 51°19'W, south Rio Grande, Bra- zil in 56 m. Etymology: The name gaucha refers to the coastal planes of Argentina, Uruguay, and southern Brazil and its peo- ple. Distribution: Eledone gaucha is knov\n onK from off Rio Grande do Sul between Solidao (30°40'S) and Chui (34°20'S) (figure 1). DISCUSSION The new species belongs in the genus Eledone because of a single row of suckers, the heteromorphic arms in the males, with the non-hectocot\ lized arms having the suckers at their tips modified into fleshy papillae or lam- inae, and the hectocot\ lus without a differentiated cal- imus. These characters distinguish Eledone from related genera Pareledone, Vosseledone, Graneledone and oth- ers (Palacio, 1978). The genus Eledone occurs on the Atlantic continental shelves of South America. Africa, and Europe and in the Mediterranean Sea. It includes six described species: E. moschata (Lamarck, 1798) and £. cirrhosa (Lamarck, Page 84 THE NAUTILUS, Vol. 102, No. 2 ;-. V" :■■ r;" ■■■:1'. . ' Vj -'T^ ■r \ mm .... !5 I,, 10 M. Haimovici, 1988 Page 85 Table 1. Ranges and means of measurements and Eledune gaticlui new species, from southern Brazil indites of 10 males and 10 females each of Eledone massyae V'oss, 1964 and Eledone mass, yae \ dss , 1964 Eledune gaucha new species Males Females Males Females Lower Upper Lower Upper Lower Upper Lower Upper Index limit Mean limit limit Mean limit limit Mean limit limit Mean limit Total length (TL) 148.0 176.4 207.0 195.0 218.2 236.0 81.0 123.2 137.0 100.0 131.9 178.0 Mantle length (ML) 45.0 54.0 63.0 60.0 65.3 71.0 21.0 31.6 41.0 28.0 35.5 50.0 Mantle width index (MWI) 65.1 76.2 88.2 75.8 79.3 88.9 47.6 61.0 71.9 40.0 59.2 70.0 Head width index (HWI) 40.4 47.4 56.5 38.2 41.9 45.0 34.2 37.5 40.0 28.0 36.2 43.6 1° right arm length index (1 ALI) 184.0 201 4 216.0 185.0 209.9 247.0 244.0 275.2 322.0 227.0 250.0 284.0 2° right arm length index (II .ALII 195.0 203.3 235.0 190.0 217.3 248.0 193.0 239.8 281.0 162.0 213.8 242.0 3° right arm length index (III ALI) 155.0 199.1 225.0 185.0 214.1 2.52.0 85.0 134.9 159.0 155.0 200.6 2.36.0 4° right arm length index (IV ALI) 191.0 204.0 224.0 186.0 215.5 243.0 134.0 208.1 256.0 162.0 191.0 213.0 Arm formula (AF) 4:2:1:3 2:4:3:1 1:2:3:4 1:2:3:4 A web depth index (A WDI) 19.1 24.3 28.5 19.8 22.5 27.4 16.8 24.2 30.9 18.9 24.4 28.6 B web depth index (B WDI) 18.2 24.5 27.5 21.0 23.8 29.6 19.0 24.1 30 1 18.9 23.9 25.8 C web depth index [C WDI) 22.9 25.9 28.3 21.2 24.1 28.9 18.8 21.6 28.9 17.6 21.1 23.7 D web depth index (D WDI) 22.7 24.8 28.6 20.9 24.3 27.6 14.6 18.6 23.0 15.8 18.3 20.5 E web depth index (E WDI) 13.4 20.6 25.3 18.6 20.8 22.9 11.5 15.6 21.6 12.3 14.9 17.4 Web formula (WE) C;D:B:A:E D:C:B:A:E A:B:C:D:E A:B:C:D:E Gill lamellae count (GiLC) 8/10 9.4/9.2 11,7 9/10 9.7/9.6 8/10 7/9 8.2/8.5 9/9 8/8 8.9/8.5 10/10 Funnel length index (ELI) 37.8 41.9 45.9 40.8 44.2 48.2 36.6 44.6 51.9 32.5 45.4 51.7 Free funnel length index (FFuLI) 17.5 23.2 29.5 20.9 23.8 27.9 14.6 21.6 31.0 10.0 21.1 30.3 Arm sucker count (ASC) 16 18.1 20 16 17.8 20 17 19.4 22 18 20.1 23 Arm sucker index I (I ASI) 6.3 i . i 9.1 7.0 7.9 8.7 4.7 7.7 9.3 6.0 6.5 8.0 Arm sucker index II (II ASI) 6.3 8.0 9.1 7.0 8.2 9.6 4.7 7.3 9.3 5.0 6.4 8.0 Arm sucker index III (III ASI) 5.5 7.4 8.9 7.0 7.9 8.5 4.7 7.6 9.6 5.0 6.0 7.5 Arm sucker index I\' (IV ASI) 5.5 7.2 8.9 6.7 7.7 8.4 4.7 6.7 7.8 3.0 5.1 6.7 Penis length index (PLI) 19.3 28.1 39.3 19.5 23.4 28.1 Penis diverticulum length index (PdLI) 6.6 15.0 22.2 4.9 7.8 10.5 Spermatophore length index (SpLD 20.9 31.6 37.7 38.3 45.0 50.0 Spermatophore w idth index (SpWI) 1.8 2.5 3.1 1.2 1.6 2.1 Hectocotvlized arm index (HcAI)' 59.0 69.2 81.4 41.7 58.9 67.4 Ligula length index (LLI) 5.3 80 97 49 8,8 12.5 1798) both from the NE Atlantic and Mediterranean, £. thijsanophora Voss, 1962 and E. caparti Adam, 1950 from the SE .\tlantic, and E. massyae Voss, 1964 and £. gaucha trom the SW .Atlantic. Eledone gaucha seems to be a relatively abundant species off Rio Grande do Sul. The possible reasons why it has not been recognized to date are its small size, its similarity to E. massyae, and the scarcity of scientific cephalopod collections by research vessels in this area. Due to its small size it is not retained in the cod ends of commercial trawlers and e\en in the R \' Atlantico Sul surveys it most often was found entangled in the wings of the net. Palacio (1977) reviewed several museum col- lections of Argentina, Uruguay, and Brazil and found Figures 2-12. Anatomical features of Eledone gaucha new species. 2. 3. Dorsal (2) and lateral (3) views of holot>pe (MORG 23544, 32 mm ML). 4. Funnel organ. 5. Upper mandible. 6. Lower mandible. 7. Digestive tract. 8. Radula. 9. Hectocot) lized arm tip 10. \on-hectocot\ lized arm tip of male 1 1. Male reproductive organs. 12. Female reproductive organs. Page 86 THE NAUTILUS, \ol. 102, No. 2 Figures 13, 14. Rpprocliictive products of Eledone gaucha new species. 13. Sperinatophore. 14. Egg. onl\ one eledoiiid. E. inaasyae. A survey of the MORG collection by the author showed one specimen of E. gau- cha (MORG 15'341) lornierK classified as E. massijae. It is expected that reviews in other collections w ill expand the range of £. gaucha. The sympatric species E. nias.syae and E. gaucha ini- tially look similar but many differences may be seen in a more detailed stud\'. In ortler to compare both species morphologicalK, the same indices were calculated for 10 males and 10 females of E. massyae {collected in the same survey) which were fixed, preserved, and measured in the same way as the new species (table 1). Eledone gaucha is smaller antl has a narrower mantle and head. The arms are thinner, longer, and decrease in size while in £. massyae all arms are approximately the same length. The hectocotvlized arm is shorter and the web depth decreases troni the dorsal to the ventral surface in E. gaucha. while in E. massyae the web is shorter only between the ventral arms. The funnel organ is W shaped in E. gaucha, w shaped in £. massyae. The number of inner and outer gill lamellae is one unit lower and the arms sucker count two units higher in E. gaucha. .Arm sucker indices are similar in males of both species, but in females they are smaller in E. gaucha. Perhaps the best single diagnostic character to distinguish mature males of both species is the spermatophore, which is shorter and much thinner in £. gaucha. ExternalK, the best distinctive character is the arm length pattern. Eledunc caparti was described b\ .Adam (1950) based on five specimens, two males and three females collected in the equatorial west .Africa at depth ranging from 60 to 170 m. No figures or tables were included in the original description. The decreasing arm length and web depth of £. caparti are similar to those of the new species. However, £. caparti does not have a supraocular cirrus, has enlarged suckers at the base of the lateral arms of the males, and the number ot suckers on the dorsal arms is almost double that in E. gaucha. The radula of £. caparti has an A2 seriation and the spermatophore is insufficiently described for comparisons. Eledone thysanophora was described by \'oss (1962) based on a single male specimen collected in a tide pool in western South Africa. The morphometric description is short, but the number of papillae on the tips of the non-hectocotylized arms and the structure of the sper- matophore, w ith the inner w all ot the horn portion lined with teeth, differentiate £. thysanophora irom the new species. Summary descriptions of £. cirrhosa (Lamarck, 1798) and £. moschata (Lamarck, 1798) are presented in Roper et al. (1984), and the species are compared b\ Rees (,1956). Both species can be distinguished from £. gaucha by several characters. Eledone cirrhosa has moderately short arms, a ridge along the mantle, non-hectocot\lized arms of males w ith a single row of compressed sucker- like cirri, and spermatophores with spines. Eledone mos- chata has subequal arms, 11 to 12 filaments on the outer hemibranch of the gills, big, sausage-shaped eggs 15 mm long, and a characteristic musk odor. ACKNOWLEDGEMENTS J. M. Andriguetto Filho and J. A. Alvarez Perez helped with collection of the specimens, G. L. Voss and an anon- ymous reviewer improved dramaticalK the final version, and E. G. Rios stimulated m\ interest in mollusks. To all of them m\' sincere gratituile. LITERATI RE CITED .Adam, W. 1950. Notes sur les cephalopodes .\.\11. Deux nou- velles especes de la cote africaine occidentale. Bulletin Institut Ro\ al des Sciences Naturelles de Beigique 2(i(45): 1-9. Haimovici, M. and J. M .Andriguetto Fo. 1986. Celalopodes costeiros capturados na pesca de arrasto do iitoral sul do Brasil .Archives de Biologia e Tecnologia. Parana 29(3): 473-495. Levi, J. A., M. Haimovici. and M. B. Concei^ao. 1985. Car- acteriza9ao eletofortica de dois morfotipos do genero Ele- done (Cephalopoda: Octopodidae). Resumes do XII Con- gresso Brasileiro de Zooiogia. (lampinas. 27 Jan to 1 Feb. 1985:39. Palacio, J. F. 1977, .A stud\ of the coastal ceplialopods from Brazil with reference to Brazilian zoogeography. Ph.D. thesis, University of Miami, 311 p. M. Haimovici, 1988 Page 87 Palacio, J. F. 1978. Vosseledorie charrua. a new Patagonian ceplialopod (Octopodidae) with notes on related genera, bulletin of Marine Science 28(2):282-296. Rees, W J. 1956. Notes on the European species ol F.lcdone with special reference to eggs and larvae. Bulletin British Museum of Natural Histor\ .3(6):283-292, pis. 9-10, Roper, C. F. E., M. J. Sweene>, and C. E. Nauen. 1984. FAO species catalogue, Vol. 3. Cephalopods of the world. FAO Fisheries Synopsis No. 125, 3:227. Roper, C. F. E. and G. L. Voss. 1983. GuideHnes for taxonomic descriptions of cephalopod species. Memoirs of the Na- tional Museum of Victoria 4449-63. Voss, G. L. 1962. Soutli African cephalopods. Transactions of the Royal Societ)' of South Africa 36(Part 4):245-272. Voss, G. L. 1964. A note on .some cephalopods from Brazil with a description of a new species of octopod: Eledone massyae. Bulletin of Marine Science of the Gulf and Ca- ribbean 14:511-516. THE NAUTILUS 102(2);88, 1988 Page 88 News and Notices .54TH ANNUAL MEETING OF THE AMERICAN MALACOLOGICAL UNION CHARLESTON. SOUTH CAROLINA RADISSON FRANCIS MARION HOTEL June 19-24, 1988 The 54th annual meeting of the American Malacological Liiioii \\ ill be held June 19-24, 19SS in (Charleston, South Carolina. Charleston is a historical cit\, many parts of which have been beautifully restored, as has the Radisson Francis Marion Hotel, which is located downtown, with- in walking distance of many restaurants, shops and other attractions. Charleston is easily accessible both by air and b\ interstate highway. Three symposia are planned: Applications of Nucleic Acid Techniques to the Study of Molluscan Evolution, convened b> Dr. M.G. Harasewych, Department of In- vertebrate Zoology, National Museum of Natural His- tory, Smithsonian Institution; S\ stematics and Evolution of Non-marine Mollusks, convened by Dr. Robert Hershler, Department of Invertebrate Zoology, National Museum of Natural History, Smithsonian Institution; and History of Malacolog\, convened by Dr. W. Backhuys, E.J. Brill, Inc Leyden, The Netherlands. In addition to these ssmposia, contributed papers and poster presentation, scheduled events w ill include a tour of historic Charleston, guided field trips to terrestrial and marine molluscan communities, an auction to benefit the s\ inposium fund, and a bantiuet. For further information, please contact: Richard E. Petit President, AMU P.O. Box 30 North Mvrtle Beach, SC 29582 USA Telephone (803) 249-1454 16TH CONCHOLOGISTS OF AMERICA CONVENTION FORT MYERS, FLORIDA SHERATON HARBOR HOUSE HOTEL July 11-15, 1988 The 16th convention of the Conchologists of ,\merica is scheduled for Jul\ 11-15, 1988. This con\ention will be headquartered in the Sheraton Harbor House Hotel in Fort M\ers, Florida, and hosted b\ the Southwest Florida Concliologist Societ\ . Con\ention acti\ ities are centered around informative, shell-related programs, fascinating field trips and interesting tours. .^ fund-raising auction, dealers bourse, and banquet are all planned. A field trip to the Sarasota Fossil Pits is scheduled for Saturda\ , Jul\- 16, 1988. Pre-registration forms and packets for the Convention, Hotel and Field Trip reservations are available from: Gene Herbert 19168 Meadow Brook Court N.W. North Fort Myers, FL 33903 USA Telephone (813) 731-2405 or Al Bridello 2265 West Gulf Drive # 240E Sanibel, FL 33957 Telephone (813) 472-1637 INSTRUCTIONS TO AUTHORS THE NAUTILUS publishes papers on all aspects of the biology and s\stematics of mollusks. 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. Notices of meetings and other items of interest to malacologists will appear in a news and notices section. Manuscripts: Each original manuscript and accompa- nying illustrations should be submitted in triplicate. 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P O Box 2255 Melbourne, FL 32902 CONSULTING EDITORS Dr. RiJdiger Bieler Department of Mollusks Delaware Museum of Natural Histor\ P.O Box 39.37' Wilmington, DE 19807 Dr. William K. Emerson Department of Living Invertebrates The .\merican 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 I'niversity C:ambridge, MA 02138 Dr. Aurele La Rocque Department of Geology The Ohio State University Columbus, 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. 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Box 3430 Silver Spring, MD 20901 THE €9 N An^LJicaiXio/i L U S CONTENTS j LIBRARY SEP 6 1988 Volume 102, Number 3 August 29, 1988 ISSN 0028-1344 Woods Hole, Mass. Timothy M. Askew A new species of pleurotomariid gastropod from the western Atlantic 89 IM. G. Harasewych Shirley A. Pomponi Timothy M. Askew Spongivory in pleurotomariid gastropods . 92 James H. McLean Ricardo Silva Absalao Renato Luiz dos Santos Cruz A new species of Macrarene (Turbinidae: Liotiinae) from Brazil 99 Geerat J. Vermeij Timothy M. Collins Nerita fortidentata, a new gastropod from the Neogene of Panama, with comments on the fossil record of Nerita in tropical America 102 Anthony D^Attilio Barbara W. Myers A new species of Favartia from the eastern Pacific (Gastropoda: Muricidae) 106 William K. Emerson Salter E. Sage III Conus baccatus G. B. Sowerby III, 1877: A Panamic faunal constituent 110 Kenneth J. Boss References to Molluscan Taxa Introduced by Linnaeus in the Systema Naturae (1758, 1767) 115 Mark E. Gordon Frederick Benjamin Isely: Biographical Sketch and malacological contributions 123 William F. Adams Andrew G. Gerberich Rediscovery of Planorbella magnifica (Pilsbry) in southeastern North Carolina 125 Donald M. McKinstry Bite by Octopus joubini: a case report 127 Oscar J. Polaco Wolfgang Mendl Occurrence of mites in Mexican land snails 129 Richard E. Petit Axelella, new name for Olssonella Petit, 1970, a preoccupied taxon (Mollusca: Cancellariacea) 130 THE NAUTILUS 102(3):89-91, 1988 Page 89 A New Species of Pleurotomariid Gastropod from the Western Atlantic Timothy M. Askew Harbor Branch Oceanographic Institution, Inc. 5600 Old Dixie Highway Fort Pierce, FL 34946, USA ABSTRACT Perotrochus charlestonensis, a new species of pleurotomariid, is described from off the coast of South Carolina. This is the 12th Recent pleurotomariid taxon to be described from the western Atlantic. Its habitat is described, environmental data are provided, and comparisons made with closely related con- geners. Key words: Gastropoda; pleurotomariid; Perotrochus; slit shells; western Atlantic; JOHNSON-SE,\-LINK INTRODUCTION Since the discovery of the first living species of the pre- dominant!) Mesozoic and Paleozoic family Pieuroto- mariidae in the western Atlantic over a century ago (Fischer & Bernard!, 1856), 24 Recent species and sub- species have been described, usually on the basis of one or a very few specimens. The habitat of these animals, generally steep-wailed, hard substrates at depths in e.xcess of 100 meters, accounts for their infrequent collection by such methods as trawling, dredging, and grab sam- pling, and, therefore, for the paucity of data on the biology and distribution of most species. Since the pub- lication of a review of the Recent pleurotomariids that included six species from the West Indies (Bayer, 1966), three species (Bayer, 1967; Rios & Mathews, 1968; Leme & Penna, 1969) and two subspecies (Okutani & Goto, 1983, 1985) have been described from the western At- lantic. Another new species of pleurotomariid, described herein, was collected while conducting fish population studies approximately 90 nautical miles east of Charles- ton, South Carolina, utilizing the submersible JOHN- SON-SEA-LINK I (Harbor Branch Oceanographic In- stitution, Inc., Fort Pierce, Florida). Bottom topography at the stud\ area was extremely rugged, making sampling by any other means difficult. SYSTEMATICS Family Pleurotomariidae Swainson, 1840 Genus Perotrochus P. Fischer, 1885 Perotrochus charlestonensis new species (figure 1) Description: Shell (figure 1) moderately large (maxi- mum diameter 87.4 mm, minimum diameter 80.1 mm, height 73.0 mm), broadly turbiniform, very thin, fragile; spire angle 89°, spire slightly convex in profile; proto- conch of 1.0 whorls, translucent, glassy; transition to te- leoconch marked by axial costae, with selenizone ap- parent by second postnuclear whorl; teleoconch of 8'/3 whorls; early whorls nearly flat-sided, becoming pro- gressively more inflated; selenizone near suture in early whorls, shifting to slightly below mid-whorl by fifth post- nuclear whorl; anal slit depth at upper margin 89°, at lower margin 57°; anal slit width 4 mm; suture adpressed; periphery rounded; base inflated, convex, non-umbili- cate; nacreous umbilical callus extending '/6 the distance from axis to periphery; spiral sculpture of 21 uniformly sized spiral cords between suture and anal slit, 20 cords of variable thickness between anal slit and periphery, 40 cords along base; selenizone with 0-5 broad cords, num- ber increasing with shell size; axial sculpture of weak nodes on early whorls (88 on fourth postnuclear whorl), forming cancellate sculpture; axial sculpture decreasing, sculpture limited to spiral cords by sixth postnuclear whorl above selenizone, and seventh postnuclear whorl below selenizone; aperture broadly ovate; columellar lip slightly thickened, weakly recurved; color creamy white with diffuse brownish orange axial streaks and blotches; na- creous layer visible through porcellaneous layer, creating iridescent hue; color lighter on base than on dorsal sur- face; selenizone margins with cream colored lines most evident on penultimate and body whorls; aperture na- creous, iridescent; operculum multispiral (7 whorls), horny, brownish-yellow, translucent; soft parts unknown. Type localitv: 90 nautical miles east of Charleston, South Carolina (32°43'80"N, 78°05'60"W), in 213 m, R/S JOHNSON-SEA-LINK I, dive 1250, August 6, 1982. Holotype: USNM 859961, maximum diameter 87.4 mm. Etymology: Named after the t\pe localit\ , commonly referred to as the Charleston Lumps. THE NAUTILUS, Vol. 102, No. 3 Figure 1. Perotrochus charlestunensis new species. Apertural, right lateral, apical, and basal views of the holotype (USNM 859961 ), off Charleston, South Carolina (32°43'80"N, 78°05'60"W), in 213 m, maximum shell diameter 87,4 mm. Ecology: This species is known only from the type lo- cality, an area of extremely rugged terrain where the bottom topograph}' consists of steep, large hills and val- leys. Topographical features (figure 2) consist of a pave- ment of relithified phosphorite and fibrous concretionary apatite composed of calcium phosphate and other min- erals (Manheim et ai, 1980). This pavement, which ranges in thickness from 10 cm to almost a meter, has been undermined in some areas, causing large pieces to break off and fall down-slope forming rubble and boulder zones. Hills range in height from several meters to about 30 meters. Valleys contain sand composed primarily of brown to black phosphorite. This area was formed during the middle Tertiary and has remained stable since the Mio- cene (Baturin, 1982). Marine life in the vicinity indicates an area of high productivity resulting from warmer Gulf Stream waters. Large snowy grouper [Epinephehts niveatus (Valen- ciennes, 1828)] and blue-lined tile fish [Caulolatilus mi- crops (Goode & Bean, 1878)] are abundant in the area together with many species of small, deep-reef fish, which generally inhabit rocky terrain. Common invertebrates include basket and brittle stars, sea urchins, solitary and colonial anemones, solitar\ corals, arrow, spider, and gal- T. M. Askew, 1988 Page 91 RCXKSOULOER LECX3E HOCK RUBBLE '-a.-.. i^^, SAND PEBBLE BARREN SAND Figure 2. Cross-section of bottom topography at collection site. Hills range in height from 3 to 30 m. atheid crabs, barrel and encrusting sponges, and hy- droids. A pink featherlike hydroid covers many of the broken boulders along the ridge tops. Prevalent gastro- pods include Perotrochus amabilis (Baser, 1963), Cal- liostoma sayana (Dall, 1889), Stenorhytis pernobilis (Fischer & Bernardi, 1857), Aurinia gouldiana (Dall, 1887), and Pterynotus phaneus (Dall, 1889). Remarks: Perotrochus charlestonensis is a member of the species complex consisting of P. midas Bayer, 1966, P. pyramiis Bayer, 1967, P. africanus (Tomlin, 1948), P. teremachii (Kuroda, 1955), P. tangaroana Bouchet & Metivier, 1982, and an undescribed species from off northwestern Australia (Group B, Bayer, 1966:745). All are characterized by having large, thin shells with in- flated whorls and proportionally large, broadly ovate ap- ertures. This new species most closely resembles P. af- ricana and Perotrochus sp. (Bayer, 1966; fig. 29) from Japan, but differs from these taxa in having a thinner shell w ith more inflated whorls, and a more convex profile of the spire. Perotrochus africanus has a more stepped spire, a more strongly recurved and thicker columella, and a broader umbilical callus (Vi distance from axis to periphery). Of the western Atlantic species, P. charles- tonensis is most similar to P. pyramus. but is more than twice the size, and is much higher-spired. Perotrochus charlestonensis also somewhat resembles Perotrochus midas, but lacks its characteristic flat, blunt spire and angular periphery. Perotrochus charlestonensis occurs in shallower water (213 m) than either P. pyramus (420- 648 m) or P. midas (600-770 m). ACKNOWLEDGEMENTS I thank the following persons, without whose help and guidance this paper would not be possible: Dr. Richard Cooper, University of Connecticut; Dr. Roger Theroux and Joseph L zmann. National Marine Fisheries Services, Woods Hole, Massachusetts; Dr. Walter Nelson and El- mer Gutherz, National Marine Fisheries Service, Pas- cagoula, Mississippi; and Tom Smoyer, Harbor Branch Oceanographic Institution photographer, for his excel- lent photographs. This is Harbor Branch Oceanographic Institution Contribution No. 642. LITERATURE CITED Baturin, G. N. 1982. Phosphorites on the sea floor — origin, composition and distribution. Developments in Sedimen- tology 33:111-112. Bayer, F. M. 1963. A new pleurotomariid gastropod trawled in the Straits of Florida by R/V Gerda. Bulletin of Marine Science of the Gulf and Caribbean 13(3):488-492. Bayer, F. M. 1966. New pleurotomariid gastropods from the western Atlantic, with a summary of the Recent species. Bulletin of Marine Science 15(4):737-796. Bayer, F. M. 1967. Another new western Adantic pleuroto- marian gastropod. Bulletin of Marine Science 17(2):389- 397. Bouchet, P. and B. Metivier. 1982. Living Pleurotomariidae (Mollusca: Gastropoda) from the South Pacific. New Zea- land Journal of Zoology 9:309-318. Dall, VV. H. 1887. [A letter containing notes on Antillean mollusks.] Conchologist's Exchange 2(1):9-10. Dall, W. H. 1889. Reports on the results of dredging ... in the Gulf of Mexico (1877-1878) and in the Caribbean Sea (1879-1880), by the U.S. Coast Survey steamer "Blake" . . . XXIX. Report on the Mollusca. Part II. — Gastropoda and Scaphopoda. Bulletin of the Museum of Comparative Zoology, Harvard 18:1-492, pis. 10-40. Fischer, P. 1885. Manuel de conchyliologie et de paleonto- logie conchyliologique. Histoire naturelle des mollusques vivants et fossiles. Fascicule 9:785-896. Libraire F. Savy, Paris, xxiv -I- 1369 p., 23 pis. (1887). Fischer, P. and A. C. Bernardi. 1856. Description dun pleu- rotomaire vivant. Journal de Conchvliologie 5:160-166, pi. 5. Fischer, P. and A. C. Bernardi. 1857. Descriptions d'especes nouvelles. Journal de Conchyliologie 5:292-300, pis, 8, 9. Kuroda, T. 1955. A new Pleurotomaria from Japan with a note on a specimen of P. rumphii Schepman collected from Taiwan. Venus 18(4):21 1-221, pis. 8, 9, Leme, J. P. L. and L. Penna. 1969. Ocorrencia de Mikado- trochus no Brasil com descri^ao de uma nova especie. Papeis Avulsos de Zoologia (Sao Paulo) 22(21 ):225-230. Manheim, F. T., R. M. Pratt, and P. F. McFarlin. 1980. Com- position and origin of phosphorite deposits of the Blake Plateau. The Society of Economic Paleontologists and Min- eralogists, Special Publication No. 29:117-137. Okutani, T. and Y. Goto. 1983. A new subspecies of Adanson's slit shell from Bermuda. Venus 42(4):305-311. Okutani, T. and Y. Goto. 1985. A new subspecies of Pero- trochus quoyanus from Bermuda. Venus 44(1):27-31. Rios, E. C. and H. R. Mathews. 1968. Nova especie de Pleu- rotomariidae do Brasil (Mollusca: Gastropoda). Arquivos Estaceo de Biologia Marinha da Universidade Federal do Ceara 8(l):65-68. Tomlin, J. R. le B. 1948. A new species of Pleurotomaria. Journal of Conchology 23:2, pi. 1. THE NAUTILUS 102(3):92-9S, 1988 Page 92 Spongivory in Pleurotomariid Gastropods M. G. Harasewych Department of Invertebrate Zoology National Museum of Natural History- Smithsonian Institution Washington, DC 20560, USA Shirley A. Pomponi Timothy M. Askew Harbor Branch Oceanographic Institution, Inc. 5600 Old Dixie Highway Ft. Pierce, FL 34946, USA ABSTRACT Direct in situ observations of feeding together with analyses of the gut contents of Perutruchus ruidas and P. amabilis in- dicate that these species feed predominantK and selectively on sponge tissue. Foraminiferal and diatom tests previously re- ported in the gut contents of pleurotomariids are derived from planktonic sediment coating the surfaces of sponges and do not significantK contribute to the nutrition of these gastropods. The family Pleurotomariidae represents an adapti\e radiation to spongivory that most likely occurred after the divergence of the herbivorous Scissurellidae and Haliotidae from the pleu- rotomariid progenitor in the late Paleozoic, but prior to the appearance of umbilicate pleurotomariids with deep anal ca- nals in the Upper Jurassic. Key words: Pleurotomariidae; diet; sponges; spongivory; Pero- trochus; Mikadotrochus, Entemnutrochus. INTRODUCTION Since the discovery of the first living species of the family Pleurotomariidae in the mid-nineteenth century, nu- merous papers have been published on various aspects of the biology and anatomy of these, the most primitive living gastropods (e.g., Bouvier & Fischer, 1899, 1902; Woodward, 1901; Fretter, 1964, 1966; Yonge, 1973; Hickman, 1984a, b). As pleurotomariids are predomi- nantly restricted to hard substrates and bathyal depths in the Recent fauna, sampling has pro\ed difficult and most published observations are based on limited ma- terial, often poorly preserved. The common occurrence of sponge spicules, forami- niferal tests, and diatoms in the alimentary systems and fecal pellets of pleurotomariids has been variously in- terpreted as being indicative of a spongivorous diet con- sisting of a single species of sponge (Woodward, 1901: 252); a diet consisting principally of sponges (Thiele, 1935:1129; Hyman, 1967:.360; Yonge k Thompson, 1976: 52); a diet of encrusting invertebrates, predominantly sponges (Hickman, 1984a:29); or detrital feeding and vegetarian diet (Fretter & Graham, 1976:1). The pres- ence of sponge spicules in the gut contents, however, is not necessarily evidence of spongivory. Although mem- bers of the pleurotomariacean family Haliotidae are known herbivores (Leighton, 1961; Leighton & Boo- lootian, 1963; Shepherd. 1973; Fretter & Graham, 1976: 6), Leighton and Boolootian (1963:229) reported sponge spicules, comprising 1-2% of the gut content \olume, in 25-50/c of the specimens of Haliotis cracherodii they examined. Similarly, Herbert (1987:289) identified sponge spicules, foraminiferans, annelid setae, and crustacean remains in the alimentary systems of members of the Solariellinae (Trochidae), a group adapted to feeding on superficial and interstitial detritus. Three species of pleu- rotomariids maintained in aquaria have been reported to feed on a wide variety of foods, including starfish, bivalve meat (Arakawa et al., 1978) and sliced, raw fish (Matsumoto et al, 1972; Sekido et al, 1976). The increasing use of research submersibles in deep sea investigations has made possible in situ observations on the feeding of two species of pleurotomariids. These observations, supported by gut content analyses of col- lected voucher material, form the basis of this report. MATERIALS AND METHODS During the course of numerous di\es aboard the research submersible JOHNSON-SEA-LINK-II throughout the northern and central Bahamas, li\ ing Perotrochus midas Bayer, 1966, were observed on 16 occasions at depths ranging 670 to 853 meters. Observations were noted and specimens photographed when practical, using a BEN- THOS 35 mm camera, with 85 mm lens. Two of the Figures 1, 2. Perotrochus midas Bayer, 1966, and Strongylophora hartmani \'an Soest, 1981, in situ. 1. Perotrochus midas feed- ing on Strongylophora hartmani. JSL-II dive 1501, #2, west end of Island at Ciouldings Cay, New Providence Island, Bahamas, 25°00'00"N, 77°34'06"\V. in 766 m. October 20, 1987. Specimen not collected Note area of sponge consumed by snail. 2. Perotrochus midas and Strongylophora hartmani along steep wall, JSL-II dive 1505, Chub Cay, Berry Islands, Bahamas, 25°22'22"N, 77°50'25"W, in 777 m. October 23, 1987. Specimen not collected. Note layer of planktonic sediment. M. G. Harasewvch et al, 1988 Page 93 Page 94 THE NAUTILUS, Vol. 102, No. 3 specimens were collected, one together with its prey, using the hydraulic arm and clamshell scoop. These spec- imens were fixed in formalin and preserved in 70% eth- anol. Fifty-six specimens of Perotrochus arnabilis (Bayer, 1963) were observed and collected during four dives aboard the research submersible Nekton Delta on the "Charleston Lumps", an area of rough bottom topog- raphy approximately 90 miles east of Charleston, South Carolina (32°43'78"-32°44'90"N, 78°05'68"-78°06'00"\V) (Askew, 1988:91), at depths ranging from 200 to 230 m. Samples were collected by suction through a 2 inch (51 mm) diameter hose. Specimens were frozen on dry ice and maintained at — 80°C. After identification of the intact sponge on which a specimen of P. midas was feeding, a spicule sample for SEM examination was prepared by digesting a portion of the sponge in 70% nitric acid (HNO5) until only sili- ceous material remained. Two specimens of P. midas and three specimens of P. amalnlis were dissected, and sections of the esophagus between the esophageal valve, situated behind the buccal mass (Fretter, 1964:181, fig. 5, ov; 1966:609, fig. 2, v), and the long sphincter at the opening of the stomach (Fretter, 1966:609) were excised. Also removed were portions of the rectum (Fretter, 1966: fig. 1, r; 1964: fig. 2, r). These sections were teased apart and examined under a dissecting microscope, then treat- ed with warm diluted bleach (1-2% sodium hypochlorite, NaOCl) to dissolve organic material while leaving the siliceous and calcified remains. The preparations were rinsed in distilled water, filtered through 0.4 ^m Nucle- pore membrane filters, and the filters mounted directly onto SEM stubs. Samples were coated with carbon and gold, and photographed using a Hitachi S-570 scanning electron microscope. A transverse section of the intact sponge was critical point dried prior to SEM examination. The following voucher material is deposited at the National Museum of Natural History: Perotrochus midas: Specimen 2. USNM 857097, JSL-II dive 1501, #2, West end of Island at Gouldings Cay, New Providence Island, Bahamas, 25°00'00"N, 77°34'06"W, in 766 m. October 20, 1987. Perotrochus amabilis: Specimens 1, 2, and 3. USNM 846900, DELTA Dive 560, 129 km due east of Charles- ton, South Carolina, USA, 32°43'95"N, 78°05'72"W, in 198-210 m. May 3, 1987. RESULTS Of the 16 sightings of Perotrochus midas. this species was observed in close proximity to, or actively feeding upon, the sponge Strongylophora hartmani Van Soest, 1980 (class Demospongiae, order Haplosclerida) on six occasions (figures 1, 2). Two specimens of P. midas were collected, one (specimen 1) together with the sponge on which it was feeding. The esophagus of both snails was distended and full of sponge tissue. Comparisons of spic- ules taken from the esophagus of both specimens of Per- otrochus midas (specimen 1, figure 5) with those of Stron- gylophora hartmani (figures 3, 4) confirmed the identity of the prey species. The rectum of specimen 1 contained spicules of S. hartmani (figures 6, 7) as well as spicules tentativeK attributed to a species of PachastreUa (figure 7). The rectal contents of specimen 2 included spicules of S. hartmani, but spicules of an unidentified sponge belonging to the order Hadromerida (figure 8) comprised an estimated 80% of the \olume. The contents of the esophagus and rectum from both specimens of P. midas consisted almost entirely (estimated >95% by volume) of sponge spicules, with foraminiferal and ostracode tests accounting for most of the other identifiable remains. Of the 53 specimens of Perotrochus amabilis observed and collected, the majority were on phosphorite blocks ranging in size from several centimeters to over a meter in length. Only three specimens were on or near a sponge. In all three instances, the sponge, which was small and roughly spherical (<6 cm diameter), could not be col- lected. Examination of the contents of the esophagus and rectum of these three specimens revealed a more het- erogeneous assemblage of sponge spicules (about 80%), diatoms, and foraminiferal tests (about 20%) (figures 9, 10). In no instance could more than an estimated 50% of the contents of either the esophagus or the rectum be attributed to a single species of sponge. DISCUSSION Direct feeding observations as well as gut content anal- yses indicate that Perotrochus midas feeds on the sponge Strongylophora hartmani b> rasping large, deep depres- sions (>2 cm diameter, >1 cm depth) in its surface (figure 1). In each of the two specimens dissected, the voluminous esophagus was distended, and contained a corresponding volume (2-3 cm') of sponge tissue. Rectal contents also consisted almost exclusively of sponge spic- ules, though from species belonging to the orders Cho- ristida and Hadromerida. The most abundant groups of deep water sponges (in terms of biomass) in the tropical western Atlantic and Caribbean are the orders Haplo- sclerida and Choristida, with the most common species often being highly silicified (Pomponi, unpublished ob- servations). Although six of the 16 sightings of P. midas were on or near a haplosclerid sponge, it is unclear Figures 3, 4. Strongylophora fiartmani Van Soest, 1981. 3. Transverse section, outer surface at top (SEM), scale bar = 300 ^lm. 4. Nitric acid spicule preparation (SEM), scale bar = 200 urn. Figure 5. Perotrochus midas, contents of mid-esophagus of spetimen 1, showing high concentration of Strongylophora hartmani spicules (SEM), scale bar = 200 ^m. Figures 6, 7. Perotrochus midas, rectal contents of specimen 1. 6. Strongylophora hartmani spicules (SEM), scale bar = 200 ^m. 7. Spicules of S. hartmani as well as of ?Pachastrella sp. (arrows) (SEM), scale bar = 200 ^m. Figure 8. Perotrochus midas, rectal contents of specimen 2, with spicules of unidentified sponge, order Hadromerida (arrows) (SEM), scale bar = 200 ^m. M. G. Harasewych et al, 1988 Page 95 Page 96 THE NAUTILUS, Vol. 102, No. 3 Figures 9, 10. Perotrochus amabilis (Bayer, 1963), contents of mid-esophagus of specimen collected 90 miles due east of Charleston, SC, in 210 m. 9. Spicule of an unidentified species, order Poecilosclerida (SEM), scale bar = 20 ^m. 10. Spicules of Strongylophora sp. (small arrow) and an unidentified species, order Choristida or Spirophorida (large arrows) (SEM), scale bar = 100 ^m. whether prey species are selected, or mereK reflect the relative abundance of sponges in a nutrient-poor envi- ronment. In either case, available evidence indicates that sponges comprise the major component of the diet of P. midas, and that the small amounts (<5%) of foraminif- eral and ostracode tests as well as other planktonic sed- iment found in the esophagus and rectum of this species were present on the surface of sponges (figures 1, 2), and probably do not contribute significantly to its nutrition. Although far more specimens of Perotrochus amabilis were observed and collected, fewer were in the proximity of a sponge. Due to the smaller size of this species and the inability to collect the sponges, no direct observations of feeding can be documented. E.xamination of the con- tents of the esophagus and rectum of three specimens indicate that sponge spicules comprise approximately 80% of the bleach insoluble mass, the remaining fraction consisting mostly of foraminiferal tests and diatom frus- tules. Fretter (1964:182) reported similar contents in the stomach of this species and concluded that the animal was a microphagous scavenger. We suggest that P. ama- bilis, like P. midas, feed exclusively on sponges, but, due to their smaller size and correspondingly shorter snout, these animals are not able to penetrate as deeply into the tissues of the sponge, and feed on surface tissues covered with deposits of planktonic sediment, thus accounting for the higher proportion of diatoms and foraminifera in the gut. With a single exception (Barnard, 1963), all published reports on the gut contents of pleurotomariids (table 1) list sponge spicules as a major component. Woodward (1901:252) was the first to speculate that the distinctive radula, shared by all pleurotomariids, was adapted for spongivory, with the hooked teeth "tearing away great pieces of the sponge , and the brush teeth used to "rasp away some of the flesh from the spicules". The occur- rence of brush or filament-tipped teeth, long considered unique to Pleurotomariidae, in unrelated, sponge-feed- ing mesogastropods of the genus Seila. has led Hickman (1984a:35) to conclude that this tooth morpholog\ is a functional adaptation to sponge predation and not a phy- logenetically constrained, conservative, morphological feature. Although exceptions have been documented (e.g., Gra- ham, 1939; Perron, 1975), archeogastropods are gener- all\ considered to be herbivores (Yonge & Thompson. 1976). This has led several authors (Yonge, 1973; Hick- man, 1984a) to imply that carnivory was not the original mode of feeding of pleurotomariids. Yonge (1973) fur- ther suggested that the change to a carnivorous diet may have been associated with the ecological shift of this family from shallow water reefs, which it inhabited dur- ing the Paleozoic and Mesozoic, to deeper water (>200 m), hard substrates by the end of the Eocene. As members of all three Recent pleurotomariid genera have radulae with filament-tipped teeth, it would appear that spongivory in Pleurotomariidae predates the diver- gence of the genus Entemnotrochus Fischer, 1885, char- acterized by a deep, broad umbilicus and an anal slit extending nearK 180° back from the aperture, from the genera Perotrochus Fischer, 1885, and Mikadotrochus Lindholm, 1927, both with shallow (<90°) anal slits and without umbilici. Inclusion of the genus Conotomaria Cox, 1959, which is also characterized by having shells w ith deep anal slits and umbilici, in the same clade as Entemnotrochus would date this divergence, and there- fore the adaptation to spongivory, prior to the Late Ju- rassic (Knight et al., 1960). The restriction of the family M. G. Harasewych et ai, 1988 Page 97 Table 1. Published reports on the contents of the alimentary system and fecal pellets of pleurotomariid gastropods. Species Food Reference Mikadotrochxis heyrichi Mikadotrochus hirasei Perotrochus africanus Perotrochus amahilis Perotrochus amahilis Perotrochus midas Sponge spicules, order Poecilosclerida Sponge spicules, orders Haplosclerida, Poecilosclerida, and Hadromerida Amorphous mass with few tiny foraminiferans Sponge spicules, foraminiferans, diatoms, and algal fragments Sponge spicules, foraminiferans, and diatoms Sponge spicules, foraminiferans, and diatoms Woodward, 1901:252 Arakawa ei ai. 1978 (table 1) Barnard, 1963:156 Fretter, 1964:182 Present study Present study to bathyal depths at the time of formation of the psy- chrosphere, the lower, cooler layer of a two-layer ocean (Bruun, 1957; Benson, 1975) was accompanied by a con- siderable reduction in diversity, compared to Paleozoic and Mesozoic fauna (Woodward, 1885). Many sponges contain secondary metabolites that are toxic (Green, 1977; Bakus & Thun, 1979). Nevertheless, mollusks, echinoderms, fishes, and marine turtles are nat- ural predators of sponges, with nudibranchs being among the most species-specific spongivores (Sara & Vacelet, 1973). Halichondria okadai (Kadota, 1922), the preferred pre\ of several species of nudibranchs, for e.xample, con- tains potent cytotoxic, antifungal, and tumor promoting compounds (Tachibana et ai, 1981; Fujiki et ai, 1987). Strongylophora hartnmni, the sponge species eaten by Perotrochus midas, contains puupehenone, a cytotoxic compound (Komoto et al.. 1987). It is possible that in- corporation of diet-derived toxic metabolites may confer some protection from predators upon pleurotomariids, but this hypothesis remains to be tested. ACKNOWLEDGEMENTS We thank Richard Cooper and Peter Auster of the NOAA National Undersea Research Program, University of Connecticut, Avery Point, for making submersible time available at the Charleston Lumps site. The assis- tance of M. Cristina Diaz with the identification of the intact sponge, and Susann Braden with the scanning elec- tron microscopy is gratefully acknowledged. This is Har- bor Branch Oceanographic Institution Contribution No. 643. LITERATURE CITED Arakawa, K. Y., D. Nakano, O. Tsukuba, and T. Hoshino. 1978. On faecal pellets and food habits of emperor's slit shell, Mikadotrochus hirasei (Pilsbry). Venus 37(3):116-120. Askew, T. M. 1988. A new species of pleurotomariid gastro- pod from the western Atlantic. The Nautilus 102(3):89- 92. Bakus, G. J. and M. Thun. 1979. Bioassays on the toxicity of Caribbean sponges. In: C. Levi and \. Esnault {eds. ). CoUoques Internationaux du C.N.R.S., No. 291, Biologie des Spongiaires, C.N.R.S., Paris, p. 417-422. Barnard, K. H. 1963. Notes on the animals Cyrina gigantea (Lam.) and Pleurotomaria africana Tomlin. Proceedings of the Malacological Society of London 35:155-158. Bayer, F. M. 1963. A new pleurotomariid gastropod trawled in the Straits of Florida by R/V Gerda. Bulletin of Marine Science of the Gulf and Caribbean 13(3):488-492. Bayer, F. M. 1966. New pleurotomariid gastropods from the western Atlantic, with a summary of the Recent species. Bulletin of Marine Science 15(4):737-796. Benson, R. H. 1975. The origin of the psychrosphere as re- corded in changes of deep-sea ostracode assemblages. Le- thaia 8:69-83. Bouvier, E. L. and H. Fischer, 1899. Reports on the results of dredging ... in the Gulf of Mexico and the Caribbean Sea, and on the east coast of the United States, 1877-1880, by the U.S. Coast Survey Steamer "Blake," . . . XXXVIII. Etude monographique des Pleurotomaires actuels. Bulletin of the Museum of Comparative Zoology, Harvard 32:193- 249. Also Published in Journal de Conchyliologie 47(2): 77-151, pis. 4-7. Bouvier, E. L. and H. Fischer. 1902. L organisation et les affinites des gasteropodes primitifs d'apres I'etude anato- mique du Pleurotomaria heyrichi. Journal de Conchy- liologie 50(2): 117-272, pis. 2-6. Bruun, A. F. 1957. Deep sea and abyssal depths. In: Hedgepeth, J. W. (ed). Treatise on marine ecology and paleontology. Geological Society of .\merica. Memoirs 67: 641-671. Cox, L. R. 1959. Thoughts on the classification of the Gas- tropoda. Proceedings of the Malacological Societv of Lon- don 33:190-202. Fischer, P. 1885. Manuel de conchyliologie et de paleonto- logie conchyliologique. Histoire naturelle des moUusques vivants et fossiles. Fascicule 9:785-896. Libraire F. Savy, Paris, xxiv -I- 1369 p., 23 pis. (1887). Fretter, V. 1964. Observations on the anatomy of Mikado- trochus amahilis Bayer. Bulletin of Marine Science of the Gulf and Caribbean 14(1):172-184. Fretter, V. 1966. Biological investigations of the deep sea. 16. Observations on the anatomy of Perotrochus. Bulletin of Marine Science 16(3):603-6i4. Fretter, V. and A. Graham. 1976. The prosobranch molluscs of Britain and Denmark. Part 1 — Pleurotomariacea, Fis- surellacea and Patellacea. The Journal of Molluscan Stud- ies Supplement l:iv -I- 37 p. Fujiki, H., M. Suganuma, H. Suguri, S. Yoshizawa, M. Ojika, K. Wakamatsu, K. Yamada, and T. Sugimura. 1987. In- duction of ornithine decarboxylase activit)- in mouse skin by a possible tumor promoter, okadaic acid. Proceedings of the Japanese Academy, Series B, 63(2):51-53. Graham, A. 1939. On the structure and function of the ali- Page 98 THE NAUTILUS, Vol. 102, No. 3 mentary canal of the style-bearing prosobranchs. Pro- ceedings of the Zoological Society of London 109:75-112. Green, G. 1977. Ecologvof toxicity in marine sponges. Marine Biology 40:207-215.' Herbert, D. G. 1987. Revision of the Solariellinae (Mollusca: Prosobranchia: Trochidae) in southern Africa. Annals of the Natal Museum 28t2):283-382. Hickman, C. S. 198-4a. Form and function of the radulae of pleurotomariid gastropods. The X'eliger 27(l):29-36. Hickman, C. S. 1984b. Pleurotomaria. pedigreed persever- ance? In: Eldridge, N. and S. M. Stanley (eds. ). Living fossils. Springer-V'erlag, New York, NY, p. 225-231. H\nian, L. H. 1967. Mollusca I. The invertebrates. Vol. 6. McGraw-Hill Book Co., New York, NY, vii -I- 792 p. Knight, J B., L. R Cox, A. M. Keen, R. L. Batten. E. L. Yochelson, and R. Robertson. 1960. Systematic descrip- tions [Archeogastropoda] In: R. C. Moore (ed.). Treatise on invertebrate paleontology, Part I, Mollusca 1. Geolog- ical Society of .America and University of Kansas Press, Lawrence,' KS, p. n60-I331. Komoto, S., O. McConnell, .\. Wright, F. Koehn, W. Thomp.son, M Lui, and K. Snader. 1987. Puupehenone, a cytotoxic metabolite from a deep water marine sponge. Journal of Natural Products 50:336. Leighton, D L 1961. Observations of the effect of diet on shell coloration in the red abalone, Haliotis rufescens Svvainson. Veliger 4:29-32, pi. 6. Leighton, D. L. and R. A. Boolootian. 1963. Diet and growth in the black abalone, Haliotis cracherodii. Ecology 44(2): 227-238. Lindholm, VV . .\. 1927. O Pleuro!.oniariabeyrichilii\geudor{ (Gastropoda) v kolleklsiakh zoologicheskogo muzeia AN 5 zametkoi o rode Pleurotomaria s. lat. Dokladv Akademii Nauk USSR 24:409-414. Matsumoto, Y., T. Kataoka, and M. Sekido. 1972. On the behavior of Beyrich's slit shell, Mikadotrochus beyrichi (Hilgendorf) kept in the aquarium. Venus 30(4): 147-152. Perron, F. 1975. Carnivorous Calliostoma (Prosobranchia: Trochidae) from the northeastern Pacific. The Veliger 18(1): 52-54, fig. 1. Sara, M. and J. V'acelet. 1973. Ecologie des Desmosponges. In: P.-P. Grasse (ed.), Traite de zoologie. Tome III. Spon- giaires. Masson et Cie, Paris, p. 462-576. Sekido, M., O. Tsukada, Y. Matsumoto. and T. Kataoka. 1976. On the keeping of Teremachi's slit shell, Perotrochus te- remachii. Journal of the Japanese .Association of Zoological Gardens and .Aquariums 18(2):49-52. Shepherd, S \. 1973. Studies on southern .Australian abalone (genus Haliotis) I. Ecology of five sympatric species. .Aus- tralian Journal of Marine and Freshwater Research 24: 217-257. Soest, R. W. M. Van 1980. Marine sponges from Curacao and other Caribbean localities Part II Haplosclerida. Studies of the Fauna of Curacao and the Caribbean Islands 62(191):1-173. Tachibana, K., P. J. Scheuer, Y. Tsukitani, H. Kikuchi, D. Van Engen, J. Clardy, Y. Gopichand, and F. J. Schmitz. 1981. Okadoic acid, a cytotoxic polyether from two marine sponges of the genus Halichondria. Journal of the Amer- ican Chemical Society 103:2469-2471 Thiele, J. 1935. Handbuch der Systematischen VVeichtier- kunde. Part 4:1129. Woodward, H. 1885. On Recent and fossil Pleurotomariae. Geological Magazine, Decade 3, 2(101:433-439, pi. 11. Woodward, M. F. 1901. The anatomy of Pleurotomaria bey- richii, Hilg The Quarterly Journal of Microscopical Sci- ence 44(2):215-268, pis. 13-16. Yonge, C M. 1973. Observation of the pleurotomarid En- temnotrochus adansoniana in its natural habitat Nature 241(5384):66-68. Yonge, C. M. and T. E. Thompson 1976. Living marine mollusks. William Collins Sons & Co. Ltd., London, 288 p., 16 pis. THE NAUTILUS 102(3):99-101, 1988 Page 99 A New Species of Macrarene (Turbinidae: Liotiinae) from Brazil James H. McLean Los Angeles County Museum of Natural Histor)- 900 Exposition Boulevard Los Angeles, California 90007, USA Ricardo Silva Absalao Renato Luiz dos Santos Cruz Departamento de Zoologia, Instituto de Biologia, CCS. Universidade Federal do Rio de Janeiro Ilha do Fundao, Rio de Janeiro, Brasil 21940 ABSTRACT The new species Macrarene digitate from the northeast Bra- zilian coast represents the first record of this principally eastern Pacific genus in the western Atlantic. The species had previ- ously been known from juvenile specimens reported as Liotia admirabilis E. A. Smith, the holotype of which is not a member of the subfamily Liotiinae. INTRODUCTION The species here described was first recognized as a mem- ber of the Brazilian fauna by Rios (1975, 1985), who referred it to Liotia admirabilis E. A. Smith, 1890. That species was described from the oceanic island of Saint Helena. According to the original description. Smith's species has a maximum dimension of I'A mm. The 15 syntypes were examined at the British Museum (Natural History) (catalogue numbers 1889.10.1.1554-68) by the senior author in 1984 and found to be similar (although not clearly referable) to the skeneiform genus Parviturbo Pilsbry & McGinty, 1945, which is not a member of the Liotiinae. The Brazilian species was clearly undescribed, but its true generic affinity was not readily apparent because the specimens available to Rios, which have been ex- amined by McLean (figure 2), were not mature and the expression of the mature lip was impossible to determine. More recently, two larger specimens have come to light and it can now be maintained that the species has the characters of the genus Macrarene Hertlein & Strong, 1951. Abbreviations for institutions are as follows: LACM, Los Angeles County Museum of Natural History; MORG, Museu Oceanografico, Universidade do Rio Grande, R.S., IBUFRJ, Instituto de Biologia, Universidade Federal do Rio de Janeiro. SYSTEMATICS Family Turbinidae Rafinesque, 1815 Subfamily Liotiinae H. & A. Adams, 1854 Shells of the subfamily are characterized by turbiniform to discoidal profiles, nacreous interiors, fine lamellar sculpture, intritacalx (calcified periostracum) in most genera, circular apertures, and multispiral opercula with calcareous beads. Radula like that of members of other turbinid subfamilies. Although previously treated by most authors as a full family, the Liotiinae have recently been ranked as a subfamily of Turbinidae by McLean (1987). Genus Macrarene Hertlein & Strong, 1951 Type species (original designation): Liotia californica Dall, 1908. Recent, off Baja California, Mexico. Macrarene species are characterized by turbinate white shells, broad umbilici, and presence of axial ribs and spiral cords that form spines at their intersections. Spac- ing of the axial ribs increases in the final whorl. In some species the ribs then become more closely spaced in the final quarter whorl. The final lip is not thickened at maturity. Some Macrarene species reach relatively large sizes. The genus differs from Arene in lacking shell pigmen- tation and in having the spacing of the axial sculpture increasingly separated as the shell matures. The white- shelled genus Liotia is smaller and retains tight spacing of the axial sculpture. The white-shelled, new world Liotiine genera Mac- rarene, Liotia, and Cyclostrema differ as a group from those of the Indo-Pacific and Australasian regions in lack- ing the thickened mature lips that characterize the gen- era Bathtjiiotina Habe, 1961, Liotina Fischer, 1885, Dentarene Iredale, 1929, and Austroliotia Cotton, 1948. Page 100 THE NAUTILUS, Vol. 102, No. 3 Figures 1, 2. Macrarene digitata new species. 1. Holotype, IBUFRJ 1562. x 7.1. 2. Immature specimen, MORG 18.359. x 10.0. For further remarks on the Indo-Pacific group see McLean (1988). There are si.\ previously described species of Macra- rene: M. californica (Dall, 1908), M. cookeana (Dall, 1908), M. diegensis McLean, 1964 (Pliocene); M. far- allonensis (A. G. Smith, 1952), M. lepidotera McLean, 1970, and M. spectahilospina Shasky, 1970. All occur offshore in the tropical to temperate eastern Pacific. Macrarene digitata new species (figures 1, 2) Description: Shell small for genus, turbinate, white, interior weakly nacreous, ma.ximum diameter 6.7 mm, whorls 3.5, aperture only slightK ohliciue, final lip not thickened. Whorls circular in outline; final w horl in con- tact with previous whorl at tips of axial ribs. Shell surface marked by microscopic lamellar growth increments; in- tritacalx present. Protoconch diameter about 200 ^m. Suture deeply impressetl, first and second whorls rising above protoconch, third whorl descending, resulting in flat-topped profile for earlv whorls. F"irst teleoconch whorl nearly smooth (except for fine lamellar sculpture), second with about 20 strong axial ribs and nine, nearly equal spiral cords defining deep, rectangular pits. Inter.sections of axial and spiral sculpture produce sharpK- projecting spines that are slightly upturned adapicalK . Spiral cords of final whorl increasing to 12; axial ribs decreasing to 15. Spines produced on final whorl by interaction of spiral and axial sculpture; spines with w eblike interconnections. Axial ribs narrow across umbilical wall, forming single descending row of sharp-pointed projections along in- nermost spiral cord. Operculum and radula unknown. Type locality: Off northeast coast of Brazil (03°59'N, 49°35'W), 100 m, Brazilian Naval Research Vessel Al- mirante Saldaiilia. station 1913, May 6, 1968, 1 speci- men. Type material: Holotype (figure 1), IBUFRJ 1562. Height 5.0 mm, diameter 6.7 mm. The holot\pe is a dead collected specimen in good condition. Parat\pe, LACM 2377, off Cabo San Roque, Rio Grande do Norte, Brazil (04°30'S, 50°03'\\'), 146 m, Brazilian Naval Re- search Vessel Almirante Saldanha. station 1921, May 8, 1968 (height 4.3 mm, diameter 6.6 mm). The paratope agrees with the holot)pe in size and sculptural details but is in subfossil condition with attached sedimentary deposits on the base. Referred material: MORG 18.359, 2 immature speci- mens [height 2.7, diameter 4.3 mm (figure 2); height 1.5, diameter 2.6] from Paripueira, Alagoas, Brazil, in beach drift collected b\ P. S. Cardoso, December, 1964; MORG 20.620, 2 immature specimens (height 2.1, diameter 3.7 mm; height 2.4, diameter 3.6 mm), Fernando de No- ronha Island, 6 m, collected b\ L. Barcellos, January, 1979. Etymology: From the Latin digitatus. having fingers. J. H. McLean et at., 1988 Page 101 Remarks: Macrarene digitata is the smallest species of the genus described to date. However, it is not certain that the holot\pe is mature. Although this genus does not form a thickened lip, maturit) in other members of the genus is indicated by closer spacing of the axial ele- ments in the final quarter whorl of growth, as indicated in the original illustration of M. spectabilospina of Shasky (1970: fig. 2). The absence of such closer spacing of the axial element suggests that a quarter whorl of additional growth (and a substantial increase in diameter) is possible for M. digitata. Macrarene digitata is unique in the genus in having all elements of the spiral sculpture of similar strength, rather than having a strongly projecting peripheral carination. Such a sculptural distinction is not regarded as a generic level character because generic characters in the Liotiinae are more reliably based on apertural morpholog\', particularly the structure of the final lip. The most characteristic feature of this species is the fingerlike aspect of the projecting spines. It cannot easily be confused with any other member of the Liotiinae. ACKNOWLEDGEMENTS We are grateful to Prof. E. C. Rios for the loan of the referred material of this species. LITERATURE CITED Dall, W. 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 California . . . ,\1V. The Mollusca and Brachiopoda Bulletin of the Mu- seum of Comparative Zoology, Harvard University 43: 205-487, pis. 1-22. Hertlein, L. G. and A. M. Strong. 1951. Eastern Pacific ex- peditions of the New York Zoological Society, XLIII. Mol- lusks from the west coast ol Mexico and Central America. Zoologica, Scientific Contributions of the New York Zoo- logical Society 36:67-120, pis. 1-11. McLean, J. H. 1964. New species of Recent and fossil west American aspidobranch gastropods. The Veliger 7:129- 133. McLean, J. H. 1970. New species of tropical eastern Pacific Gastropoda. Malacological Review 2:115-130. McLean, J. H. 1987. Angariinae and Liotiinae — the primitive living trochaceans. .Annual Report of the Western Society of Malacologists 19:16. McLean, J. H. 1988. Two new species of Liotiinae (Gastropo- da: Turbinidae) from the Philippine Islands. The Veliger 30:408-411. Rios, E. C. 1975. Brazilian marine mollusks iconography. Museu Oceanografico, Fundagao Universidade do Rio Grande, 331 p., 91 pis. Rios, E. C. 1985. Seashells of Brazil. Museu Oceanografico, Funda^ao Universidade do Rio Grande, 328 p., 102 pis. Shasky, D. R. 1970. New gastropod taxa from tropical western America. The Veliger 13:188-195. Smith, A. G. 1952. Shells from the bird guano of southeast Farallon Island, California, with description of a new species of Liotia. Proceedings of the California Academy of Sci- ences, Series 4, 27:383-387. Smith, E. A. 1890. Report on the marine Mollusca of the island of Sta. Helena. Proceedings of the Zoological Society of London 1890:247-322, pis. 21-24. THE NAUTILUS 102(3): 102-105, 1988 Page 102 Nerita fortidentata, a New Gastropod from the Neogene of Panama, with Comments on the Fossil Record of Nerita in Tropical America Geerat J. Vermeij Department of Zoology University of Maryland College Park, MD 20742, USA Timothy M. Collins Department of Geology and Geophysics Yale University New Haven, CT 06520, USA ABSTRACT Nerita fortidentata new species is described from the Neogene of Bocas del Toro, Panama It is most closely related to the Recent Caribbean \. fulgurans Gmelin, 1791. The fossil record and biogeography of tropical American Nerita are reviewed. At least two lineages of Nerita present in tropical America during the Tertiary have become restricted in the Recent fauna tn the Infln-Wf^t-Pacific region INTRODUCTION Neritid gastropods are prominent members of tropical rocky intertidai communities. Because ihe fossilization potential of tfiese animals is poor, little is known about tlie historical development of the genus Serita Linnaeus, 1758. It was, therefore, of considerable interest to find an excellently preserved specimen of an apparently hith- erto unrecognized species from the Neogene of tropical America. Here we describe the new species and review briefly some biogeographically interesting aspects of the history of the genus Nerita in tropical America. METHODS Species of Nerita are distinguished conchologically by characters of shape, apertural dentition, external sculp- ture, form and sculpture of the parietal callus, and the shape and sculpture of the calcareous operculum. Two ratios are especially helpful in describing the overall shell form of Nerita (X'ermeij, 1973). The first is globosity, G, defined as the distance H, between the dorsal surface of the body whorl and the center of the parietal callus divided by the geometric mean betw een the shell's major diameter Dj and minor diameter D2: G = H,/(D,D2)'''. The second ratio is the degree of basal excavation. The plane of the parietal callus typically lies at an angle to the horizontal w hen the shell lies aperture-down on a flat surface. The greater the angle, the greater is the degree of basal excavation. An approximation of the de- gree of basal excavation is given by the ratio E = H2/ H,, where Ho is the distance from the horizontal plane on w hich the shell rests to the dorsal surface of the body whorl. SYSTEMATIC DESCRIPTION Class Gastropoda Subclass Prosobranchia Order Neritacea Family Neritidae Genus Nerita Linnaeus, 1758 Type species: Nerita peloronta 1758, Recent, tropical Western Atlantic. Subgenus Theliostyla Morch, 1852 Type species: Nerita albicilla Linnaeus, 1758, Recent, Indo- West-Pacific. Nerita (Theliostyla) fortidentata new species (figures 1, 2) Diagnosis: Shell thick, moderately globose (G = 0.59), base little excavated (E = 1.10), apex of spire barely raised above rest of shell. Outer lip very thick, inner edge with 12 strong teeth; two teeth nearest spire \er\ large and protruding, as is third tooth from abapical end of lip; columellar lip with tw^o strong centrally placed teeth; adapical portion of parietal region with a fold of about the same size and strength as adapical tooth, w hich curves into aperture; sculpture consisting of 21 regularK -spaced flat-topped smooth spiral cords, w hich Dare slightly from base to barely overhang incised interspaces about one- third the width of ribs; parietal callus small, its surface sculptured with about 10 strong ridges that bear up to 3 large granules each; holotype shows faint radial color pattern of alternating continuous and discontinuous pro- socline bands of off white and grey-black; operculum unknown. G. J. Vermeij and T. M. Collins, 1988 Page 103 Figure 1. Nerita fortidentata new species, from Bocas del Toro, Panama, Holotype, USNM 423644, height 19.7 mm, Apertural view, showing thickened outer lip and enlarged teeth on adapical portion of outer lip. Holotype: United States National Museum number 423644. Major diameter 21.3 mm, minor diameter 16.9 mm, Hi 11.2 mm, H^ 12.3 mm, standard shell height 19.7 mm (apex abraded), standard shell diameter 19.9 mm, shell thickness at midpoint of outer lip 3.5 mm. Type locality: Panama, Province of Bocas del Toro, Archipelago of Bocas del Toro, Punta Robalo quadrangle. Island of Cayo Agua, eastern side about 400 meters south of Punta Nispero on the shoreline in clayey, tuffaceous, quartzose, blue-grey siltstones with dense shelly horizons. We have followed Woodring (1982) in referring to the Late Miocene-Pliocene deposits of the Bocas del Toro area as the Limones Formation. The true relationships between the Miocene-Pliocene of Bocas del Toro with respect to the Costan Rican Limones Formation and the Gatun Formation of the Canal Zone have not been elu- cidated. Laurel B>bell of the U.S.G.S. (personal com- munication) has assigned a preliminary age of Late Mio- cene to Early Pliocene to the locality from which the holotype of N. fortidentata was collected. This age de- termination is based on the presence of the calcareous nannofossils Sphenolithiis abies Deflandre, in Deflandre and Fert, 1954 (last occurrence middle Pliocene), and Discoaster brouweri Tan, 1927 (first occurrence middle Miocene). Thomas M. Cronin, U.S.G.S. (personal com- munication), examined the ostracode faunas from several adjacent localities of the same formation on Cayo Agua. He noted a remarkable similarity between the ostracodes from these samples and the ostracode fauna described by van den Bold (1967) from the type Gatun Formation of the Canal Zone. On the basis of these similarities he suggests a preliminary age of Late Miocene for this fau- na. Harry Dowsett, also of the U.S.G.S. (personal com- munication), examined the planktic foraminifera from an adjacent localit\ of the same formation on Cayo Agua and found an assemblage indicative of planktic zone N17-NT8 (Late Miocene-Early Pliocene). The consensus at this stage, therefore, is that the beds from which N. fortidentata was collected are Late Miocene to Early Pliocene in age. Figure 2. Nerita fortidentata new species, from Bocas del Toro, Panama. Holotype, UNSM 423644, height 19.7 mm. Ab- apertural view. Remarks: The new species clearly belongs to the sub- genus Theliostyla Morch, 1852 (type N. albicilla Lin- naeus, 1758), which is characterized by granulate sculp- ture on the parietal region, a barely protruding spire, and w ell-developed external spiral sculpture. Among the four Recent species of this subgenus in tropical America, N.fulgurans Gmelin, 1791, bears the closest resemblance to A', fortidentata. Measurements of 17 specimens of N. fulgurans in the Vermeij collection from the Atlantic coasts of Panama, Costa Rica, Venezuela, and Jamaica show that this species is less globose (G = 0.54 ± 0.020, range 0.50-0.57) and basally much more excavated (E = 1.27 ± 0.05, range 1.21-1.39) than is the new species. Nerita funiculata Menke, 1851, the Recent east- ern Pacific cognate of N. fulgurans, is also less globose (G = 0.51 ± 0.04, range 0.42-0.58, based on 15 speci- mens in the Vermeij collection from Costa Rica, Panama, and Ecuador) and more excavated (E = 1.28 ± 0.15, range 1.13-1.60) than is N. fortidentata. Both N. ful- gurans and N. funiculata have weaker and more nu- merous denticles on the outer lip, weaker and more finely granulated ridges on the parietal region, and spiral cords that are more numerous and more variable in size on the body whorl (18-35 in N. fulgurans, usually more than 30 in N. funiculata). The spiral cords of N. fulgurans show a tendency to bifurcate on the body whorl, whereas no such tendencN is seen in iV. fortidentata. The three subspecies of N. ascensionensis Gmelin, 1791, from is- lands in the tropical south Atlantic (Vermeij, 1970) differ from iV. fortidentata by having a nearly smooth parietal region and by the very weak dentition on the outer lip. The West Indian A', tessellata Gmelin, 1791. differs from A', fortidentata b\' having low rounded spiral cords bro- ken irregularl) bv high and low areas correlating to the characteristic black and white checkered pattern found in this species, a finely granulated parietal region of relatively large extent, and a weakK denticulated outer lip (Russell, 1941). Jung (1965) recorded Serita fulgurans from the Mid- dle Miocene and Upper Pliocene of Venezuela, but he pointed out that his specimens differed from Recent shells by having stronger apertural dentition and a less concave Page 104 THE NAUTILUS, Vol. 102, No. 3 (that is, less excavated) parietal region. Later Jung (1969) found a similar shell in the Late Miocene Melajo Clay Member of the Springvale Formation of Trinidad. Like the Venezuelan material, the shell from Trinidad has only 16 ribs, but instead of having 2 centrali\ placed columcllar teeth, as in the Venezuelan material, the Trin- idad specimen has one upper tooth which curves into the aperture (this upper tooth is probably equivalent to the parietal fold found on the tvpe of \. fortidentata] and 2 somewhat lower denticles. Jung tentati\ely re- ferred both lots to N. exuvioides Trechmann, 1935, a species described on the basis of one incomplete speci- men from the Pliocene of Carriacou in the Grenadines. Jung (1971) redescribed this latter specimen as having only 12 ribs whose edges overhang the adjacent inter- spaces. Vokes (1983) clarified the status of N. exuvioides when she described a very strongly ribbed shell with 1 1 ribs from the Gatun Formation of Panama. This speci- men closely resembles the one from Carriacou and is clearly referable to S. exuvioides. We believe that Jung's (1965, 1969) specimens from Venezuela and Trinidad belong neither to N. fulgurans nor to N. exuvioides, but instead to our new species, iV. fortidentata. This species appears therefore to be intermediate in sculpture be- tween N. exuvioides with only 1 1-12 ribs and the Recent .v. fulgurans, usually with more than 21 ribs. The re- lationship between N. fortidentata and the Late Oli- gocene or Early Miocene N. tampaensis Dall, 1892, from the Tampa Formation of Florida is unclear. Merita tam- paensis, whose granulated parietal region suggests place- ment in Theliostyla, is a small species with weakly de- veloped apertural dentition and highly \ariable external sculpture, some shells being nearly smooth whereas oth- ers have fine spiral cords of varying sizes. The shape of xV. fortidentata suggests that this species inhabited the upper zones of rocky shores. Merita ful- gurans, its most similar living relative, is usually found in areas of reduced salinity , such as the mouths of harbors (Russell, 1941) or protected embayments. Vermeij (1973) showed that shells with low globosity, high basal exca- vation, weak sculpture, and relatively broad apertures with weak dentition are found in middle to lower inter- tidal species of Merita; whereas species with a globose, little excavated, strongly sculptured shell and a small aperture bordered by strong teeth are found at higher shore levels. The latter shell form is especially charac- teristic of the subgenera Cyrnostyla von Martens, 1887, and Ritena Gray, 1858. Of the living and fo.ssil members of the subgenus Theliostyla, most of which live in the middle zones of the intertidal, M . fortidentata most closely approaches species of Ritena. Other fossils collected with N. fortidentata, including Oliva, Olivella, Conus, Na- tica, Polinices, Strombus, Phalium, Dentalinm. and Corlmla, suggest a variety of different environments, implying post-mortem transport and mixing of assem- blages. BIOGEOGRAPHY OF AMERICAN MERITA Among the fossil species of Merita that have been de- scribed from late Eocene and younger strata in tropical .\merica, at least two have close affinities with li\ing Indo-\^'est-Paci£ic species. Merita listrota Woodring, 1973, from the late Eocene (?) Gatuncillo Formation of Panama has a finely ribbed shell w ith a peripheral keel, fine teeth on the outer lip, 7 teeth on the columellar lip, and a sparseK papillate parietal region. Woodring (1973) noted the striking similarity' between A', listrota and the recent mangrove-associated M. planospira Anton, 1839 (the type and only known species of the subgenus Ily- nerita von Martens, 1887) from the tropical Indo-Pacific. He doubted that the tw^o species were closely related, in part because M. planospira has 5 rather than 7 columellar denticles. We consider the similarities to be so numerous that an inference of close relationship seems warranted. If A', listrota belongs to the subgenus Ilynerita, as we believe it does, that subgenus may be added to the grow- ing list of taxa whose distributions became restricted to the Indo- West-Pacific during the Tertiary (N'ermeij, 1986). As Vokes (1983) points out, \. (Theliostyla) exu- vioides may represent a second lineage that has become restricted (as N. exuvia Linnaeus, 1758) to the Indo- West-Pacific. Merita exuvioides differs from the Western Pacific M. exuvia chiefly by having 1 1 instead of 14 strong overhanging spiral cords on the body whorl. The other fossil species of Merita that have been de- scribed from late Eocene and younger deposits in tropical America do not easih fit with any living members of the genus. These are M. hadra Woodring, 1973, from the late Eocene (?) Gatuncillo Formation of Panama and N. oligopleura Dall and Ochsner, 1928, from the Pleistocene of the Galapagos. Merita hadra has very fine spiral threads on the bod\' whorl and a smooth parietal region, whereas M. oligopleura has 3 broad spiral ribs on the body whorl. Although the record of Merita in tropical America is very meager, the history of the genus points to multiple instances of extinction and geographical restriction. It is too earl\ to assess the scope of these changes, but the record of Merita suggests that intertidal species have been no less affected by events leading to extinction and re- striction than have species from the better-sampled fossil environments of subtidal bottoms. ACKNOWLEDGEMENTS T.M.C. gratefully acknowledges a Smithsonian Tropical Research Institute short-term fellow ship, directed by Jer- emy Jackson, during w hicli large collections of Late Ter- tiary fossil mollusks were made. Collecting was made more fruitful and pleasant by the expertise and company of the other members of the field part\-, A. G. and J. M. Coates. We thank Laurel B\ bell, Thomas M. Cronin, and Harry Dowsett of the U.S.G.S. for their age determi- nations. LITERATURE CITED Anton, H. E. 1839. Verzeichniss der Conchylien welche sich in der Sammlung von Hermann Eduard .^nton befinded. Halle, xvi -I- 110 p Bold, W. A. van den. 1967. Ostracoda of the Gatun For- mation, Panama. Micropaleontology 13(3):306-318. G. J. Vermeij and T. M. Collins, 1988 Page 105 Dall, W. H. 1892. Contributions to the Tertiary fauna of Florida; with especial reference to to the Miocene silex beds of Tampa and the Pliocene beds of the Caloosahatchie River. Transactions of the Wagner Free Institute of Sci- ence 3(2):201-473, pis. 13-22. Dall, W. H. and W. H. Ochsner. 1928. Tertiary and Pleis- tocene Mollusca from the Galapagos Islands. Proceedings of the California Academy of Science 17{4):89-139, pis. 2-7. Gray, J. E. 1858. Observations on the genus Nerita and its operculum. Proceedings of the Zoological Society of Lon- don 26:92-94. Gmelin, J. F. 1791. In: Linnaeus' Systema naturae, Tom. I, Pare VI, p. 3021-3909. Jung, P. 1965. Miocene Mollusca from the Paraguana Pen- insula, Venezuela. Bulletins of American Paleontology 49(223):389-652. Jung, P. 1969. Miocene and Pliocene mollusks from Trinidad. Bulletins of American Paleontology 55(247):293-657. Jung, P. 1971. Fossil molluscs from Carriacou, West Indies. Bulletins of American Paleontology 61(269):147-262. Linnaeus, C. 1758. Systema naturae, 10th ed. Stockholm, 824 p. Martens, E. von. 1887-89. Die Gattungen Nerita und Neri- topsis. Svstematisches Conchylien-Cabinet von Martini und Chemnitz 2(11):1-147. Menke, K. T. 1851. Conchylien von Mazatlan, mit kritischen Bemerkungen. Zeitschrift fiir Malakozoologie, yr. 8. Morch, O. A. L. 1852 Catalogus conchyliorum quae reliquit D. Alphonso d Aguirra & Gadea Comes de Yoldi, Copen- hagen, 170 p. Russel, H. D. 1941. The Recent molluscs of the family Ne- ritidae of the western .Atlantic. Bulletin of the Museum of Comparative Zoology at Harvard College 88(4):347-404. Trechmann, C. T. 1935. The geology and fossils of Carriacou, West Indies. The Geological Magazine 72(858):528-555, pis. 20-22. Vermeij, G. J. 1970. The Nerita ascensionensis species com- plex (Gastropoda: Prosobranchia) in the South Atlantic. The Veliger 13(2):135-138. Vermeij, G. J. 1973. Morphological patterns in high intertidal gastropods: adaptive strategies and their limitations. Ma- rine Biology 20:319-346. Vermeij, G. J. 1984. The systematic position of the neritid prosobranch gastropod Nerita polita and related species. Proceedings of the Biological Society of Washington 97(4): 688-692. Vermeij, G. J. 1986. Survival during biotic crises: the prop- erties and evolutionary significance of refuges. In: D. M. Elliott (ed.). Dynamics of extinction. Wiley, New York, p. 234-246. Vokes, E. H. 1983. Nerita exuvioides Trechmann (Mollusca: Gastropoda) from the Gatun Formation of Panama. Tu- lane Studies in Geology and Paleontology 17(4): 131-134. Woodring, W. P. 1973. Geology and paleontology of Canal Zone and adjoining parts of Panama: description of Ter- tiary Mollusks (additions to gastropods, scaphopods, pe- lecypods: Nuculidae to Malleidae). U.S. Geological Survey Professional Paper 306-E:453-539. Woodring, W, P. 1982. Geology and paleontology of Canal Zone and adjoining parts of Panama: description of Ter- tiary Mollusks (Pelecypods: Propeamussidae to Cuspida- riidae; additions to families covered in P.306-E; additions to gastropods; cephalopods). U.S. Geological Survey Professional Paper 306-F:541-759. THE NAUTILUS 102{3):106-1{)9, 1988 Page 106 A New Species of Favartia from the Eastern Pacific (Gastropoda: Muricidae) Anthony D'Altilio Barbara ^ . Myers Department of Marine Invertebrates San Diego Natural History Museum San Diego, CA 92101, USA ABSTRACT Favartia (Murexiella) shasktji is described from Isla del Coco, Costa Rica, and compared with related species from the eastern Pacific, This species is known onl\ from this isolated oceanic island INTRODUCTION Isla del Coco (also known as Cocos Island), one of the National Parks of Costa Rica, is a small, uninhabited island situated approximately 600 kilometers south south- west of Puntarenas, Costa Rica, at 5°33'N latitude and 87°03'W longitude. Isla Cascara and Roca Sucia are two of the many islets surrounding Cocos Island. In May, 1985, Donald R. Shasky of Redlands, California, and Kirstie L. Kaiser of La Canada, California, collected five specimens of the new species described herein, at depths of 50-80 feet (15.2-24.4 m), under dead coral off these two islets. In a previous paper (D'Attilio, M>ers & Shasky, et al., 1987), a new species of Phyllonotus Swainson, 1833, was described from the same area. Montoya (1983, 1984) published a bibliography of Cocos Island molluscan faunal studies. SYSTEMATICS Family Muricidae Rafinesque, 1815 SubfamiK Muricopsinae Radvvin & D',\ttilio, 1971 Genus Favartia Jousseaume, 1880 Type species: Miirex breviculus Sowerby , 1 834, by orig- inal designation. Subgenus Murexiella Clench & Perez Farfante, 1945 Type species: Mtirex hidalgoi Crosse, 1869, b>- original designation. Favartia (Murexiella i shaskyi new species (figures 1-10) Description: Shell (figures 1, 2) broadly fusiform, spire '/3 shell length; protoconch of holot\pe eroded, proto- conch of paratype 1 (figure 3) of 3'/2 smooth, lustrous, convex whorls, with axial buttresses arising from the te- leoconch; teleoconch with 5-6 subangulate whorls; suture weakly impressed; whorls gentK sloping from suture to shoulder; body whorl % shell length; aperture ovate; in- ner lip erect posteriorly; outer lip thin, erect, crenulate, reflecting the spiral cords; siphonal canal '3 shell length, broad proximalK', tapering distalK', with narrow \entral opening, terminally recurved, tube-like; siphonal fascicle of 3 fine distal portions of previous canals; body whorl with 6 broad varices, penultimate whorl with 8 varices; varices broader than intervarical regions; spiral sculpture of 6 cords on body whorl, all nearK equal in width, packed closely together; 2 additional cords between body whorl and siphonal canal, 2 major and 1 minor cord on canal; 2 cords per whorl on spire; shoulder of body whorl without spiral cords; all cords terminate as spines on varices (figures 4, 5), posterior spines recurved, anterior spines long, projecting ventrally; spiral cords (figures 6, 7) strongly scabrous; scales prominent, fine, white, erect, closely packed, disguising the contour of cords; cords and scales microscopicalK grooved, incre- mentally incised; adapertural sides of varices, especially last varix, completeK- scaled; scales arranged in 3 tiers (figure 6), with tube-like spines on tier farthest from aperture; radula (figure 8) t>picall\ muricopsine, with broad, U-shaped basal plate, and strongK projecting cusps. Paratypes 1 and 2 with only 4 postnuclear whorls; suture more strongly impressed, spire angulate. Figures 1, 2. Favartia (Murexiella) shaskyi new species. 1 . Holot> pe, L'SNM 860012, Isla Cascara, Cocos Island, Costa Rica, under dead coral slab, in 24.4 m, 23.0 mm long. 2. Paratype 1, SDNHM 91873, Roca Sucia, Cocos Island, Costa Rica, under dead coral slab, in 24.4 m, 14.0 mm long. A. D'Attilio and B. W. Myers, 1988 Page 107 Page 108 THE NAUTILUS. Vol. 102, \o. 3 Figures 3-7. Favartia (Murexiella) shaskyi new species, details of shell sculpture 3. Protoconch of parat\pe 1. 4, 5. Adapertural (4) and abapertural (5) views of last varix of holotype. 6, 7. Microscuipture along adapertural (6) and abapertural (7) surfaces of a spiral cord of the holotype. Figure 8. Rachidian and right lateral teeth from the holotype. Color: Base color buff to tan, with diffuse darker band encircling body whorl; scales white, aperture white, si- phonal canal white. Type locality: Isla Cascara, Cocos Island, Costa Rica, under dead coral slab, in 24.4 m. Holotype: USNM 860012 (figure 1 ), 23.0 mm long, 14.2 mm wide. Paratypes: Paratype 1: SDNHM 91873 (figure 2), 14.0 mm long. Paratype 2: Collection of D. R. Shasky, 11.8 mm long, both from Roca Sucia, Cocos Island, Costa Rica, under dead coral, in 24.4 m. Additional material examined: Tw o specimens, collec- tion of K. Kaiser, 19.2 mm long, and 14.7 mm long, Isla Cascara, Cocos Island, Costa Rica, under rocks, in 15.2- 24.4 m. Etymology: We are pleased to name this species for Donald R. Shasky, M.D., who collected the three type specimens, and who generousK donated the holotype and parat\pe 1. DISCUSSION This new species has a distinct morphology that easily distinguishes it from all other eastern Pacific species of A. D'Attilio and B. W. Myers, 1988 Page 109 the subgenus Murexiella. Favartia (Murexiella) lappa (Broderip, 1833), a closely related species, differs in hav- ing a higher spire, biconic form, and short, stubby, non- recurved spines. Favartia (Murexiella) vittata (Broderip, 1833) also has a more or less biconic shape, but the body whorl is more globose, and the spines, although recurved, are short and stubby. Favartia (Murexiella) keenae (E. H. Yokes, 1970) has somewhat similar sculpture, a larger shell with a globose body whorl strongly constricted at the base, and a strongly impressed suture. We have care- fully studied and compared the 12 additional nominal species of Murexiella, none of which are closely related to this new species. ACKNOWLEDGEMENTS We are grateful to Dr. Donald R. Shasky for donating the holotype and paratype and Kirstie Kaiser for the loan of her two specimens. We thank David K. Mulliner for the photography. M. G. Harasewych, EmiK H. Yokes, William K. Emerson and Carole M. Hertz reviewed the manuscript and made valuable suggestions. LITERATURE CITED Broderip, W. 1833. Characters of new species of Mollusca and Conchifera collected by Mr. Cuming. Proceedings of the Zoological Society of London 2:173-179. Clench, W. J. and I. Perez Farf ante. 1945. The genus Mt/rei in the western Atlantic. Johnsonia l(17):l-58. Crosse, H. 1869. Diagnoses Molliiscorum novorum. Journal de Conchyiiologie 17:408-410. D'Attilio, A., B W. Myers, and D. R. Shasky. 1987. A new species of Phyllonotus (Muricidac: Muricinae) from Isla del Coco, Costa Rica. The Nautilus 101(4):162-165, Jousseaume, F. 1880. Division methodique de la famille des Purpurides. Le Naturaliste 42:335-336. Montoya, M. 1983. Los Moluscos marines del la Isla del Coco, Costa Rica. I. Lista anotada de especies. Brensia 21:325- 353. Montoya, M. 1984. Marine mollusks of Cocos Island, Costa Rica. I. Bibliographic compilation of species. Western So- ciety of Malacologists Annual Report (1983) 16:33-44, Radwin, G. E. and A. D'Attilio. 1971. Muricacean supra- specific taxonomy based on shell and radula. Echo 4:55- 67. Rafinesque, C. S. 1815. Analyse de la nature ou tableau du univers et des corps organises. Barravecchia, Palermo, p. 136-149. Sowerby, G. B., II. 1834. Conchological illustrations. Murex. Sowerby, London, pis. 58-67. Swainson, W. 1833. The zoological illustrations, ser. 2, vol. 3, pi. 67. Yokes, E. H. 1970. The west American species of Murexiella (Gastropoda: Muricidae). Veliger 12(3):325-329, pi. 50. THE NAUTILUS 102(3):110-114, 1988 Page 110 Conus baccatus G. B. Sowerby 111, 1877 A Panamic Fauna! Constituent ^ illiam K. Emerson Waller E. Sage III Department of Invertebrates American Museum of Natural History New York, NY 10024, USA ABSTRACT Specimens of a small species of Conus recent!) received from Golfo de Chiriqui, Republica de Panama, are confirmed to be referable to Conus baccatus Sowerby , 1877, a species originally described from an unknown locality. The provenance and iden- tity of this taxon had remained uncertain for more than 100 years until Rockel (198.5a) compared two specimens from Pa- cific Panama in his collection with the holotype of Conus bac- catus and determined the specimens to be conspecific. We agree with Rockel's conclusion that this species has been con- fused in the past w ith the pustulate form of the west American Conus perplexus Sowerby, 1857, which is a somewhat similar, but distinct species. For Conus perplexus, a lectotype is selected and the type locality is restricted to the Golfo de Panama. For Conus baccatus. the Golfo de Chiriqui is designated the type locality. INTRODUCTION In 1877, G. B. So\verb%- III briefly described and illus- trated in color Conus baccatus from an unknown locality. Apparently based on a single specimen in the collection of Dr. Prevost of Alen^on, France, the figured specimen later was owned by J. C. Melvili (Sowerby, 1887:251) and subsec}uently by J. R. Le B. Tomlin (1937:217). The vast MeK ill-Tomlin Collection eventual!) w as deposited, along with this type, in the National Museum of Wales, Cardiff. Coomans et al. (1982:4) examined the holotype and provisionally accepted Conus baccatus as a valid species. They also rejected the Cjuestionable placement by Walls (1979:726) of this ta.xon in the synonymy of C. mindanus Hwass in Bruguiere, 1792, from the western Atlantic. \'ink (1984:356) subsequently noted certain similarities of the holotype of C. baccatus with C. selenae Van Mol, Tursch, and Kempf, 1967, a Brazilian taxon which we consider referable to the C. jaspidcus (Jmelin, 1791, species complex. Through the generosit)- of Carol Skoglund and Robert Koch, we have examined a series of well-preserved spec- imens from Golfo de Chiriqui. Panama that are referable to Coijus baccatus. Our findings confirm Rockel's (1985a: 29) conclusion that this taxon is a valid Pacific Panamic species, which for many years has been masquerading in collections as a pustulose form of Conns perplexus Sowerb), 1857. A specimen apparently referable to C. baccatus was illustrated by Kiener (1846:56, 57, pi. 83, fig. 2) as "Conus albomaculatus. Reeve ", in reference to Sow.[erby] (1833, Conus fig. 2, which was named C. bicolor h\ Sowerby in 1833 and renamed C. albomaculatus h\ Sowerb) in 1841). Kiener "s figured specimen, measuring 22 mm in height, was attributed to the Dupont Collection from an unknown locality. This specimen cannot be located in the Museum National d Histoire Naturelle, Paris, and the fate of the Dupont collection is not known (P. Bou- chet, in lift.. March 4, 1987). Reeve (1849:3) considered Kiener 's illustrations to represent the western Atlantic species C. mindanus Hwass in Bruguiere, 1792. He also stated that "C. albimaculalus [sic] [Sowerb) ] has more resemblance with very young [pustulose] specimens of C. lithoglyphus [.sir] [Hwass in Bruguiere, 1792] ', a con- clusion accepted by Coomans et al. (1979:97) and Rocke! (1985b, nr. 22). Sowerb)- "s figured specimen of C. albo- maculatus has not been located. It is not in the Britisli Museum (Natural History) (K, M. Way, in litt.. May 11, Figures 1-7. Conus baccatus Sowerby, 1877. 1, 2. Holotype, NMW no. 1955.158.29; x 2 (courtesy of R. M Filmer) 3. 4.. Off Isla Coiba, Panama, AMNH no, 221871a; x 2. 5. Off Isla Parida, Panama, AMNH no. 173698a; x 5 6, 7. Off Isla Coiba, Panama. AMNH no. 221871; x 2, Figures 8-16. Conus perplexus Sowerby, 1857, 8. 9. Lectotype, BM(NH) no. 1978118; x 2. 10. Pla\a de los Angeles, Bahia Tenacalita, Jalisco, Mexico, dredged, mud bottom, Aug., 1975, AMNH no. 221873a, ex C and P. Skoglund; X 5. 11, 12. Paralectotype, BM(NH) no. 1978118a; x 2 13, 14. Paralectotype, BM(NH) no. 1978118b; x 2. 15. 16. "West Panama" (note the distorted spire), AMNH no. 212547; x 2 Figures 17. 18. Conus puncticulatus form papillosus Kiener, 1849, Cartagena, Colombia, Iseach, 1977, ex J. M. Bijur Coll., AMNH no. 225979; x 2. Figure 19. Conus yemanjae \aii Mol et al., 1967, paratype, pi. 8, fig. lb, Fortaleza (Ceara), Brazil, ex pisce; x 2. W. K. Emerson and W. E. Sage III, 1988 Page 111 Page 112 THE NAUTILUS, Vol. 102, No. 3 1987) nor is it in the National Museum of Wales (A. Trevv, in litt.. Ma\, 1987). Therefore, the taxonomic status of C. alboviaculatus Sowerby, 1841, cannot be determined from the available data. Although C. baccatus was not formally named by Sow- erb\ ill until 1877, specimens were apparentl\ available in European collections by the nii(l-I9th century, as sug- gested by Kiener's figured specimen from the Dupont collection. There is also a specimen of C. baccatus labeled ""Panama" in the F. A. Constable Collection (AMNH 47740), which dates from the latter part of the 19th century and was received by the American Museum of Natural History from the estate of Louise Constable in 1929. Abbreviations for institutions used in text; AMNH = .\merican Museum of Natural History; BM(NH) = Brit- ish Museum (Natural History); Los Angeles County Mu- seum of Natural History = LACMNH; NMW = National Museum of Wales. SYSTEMATIC ACCOUNT Conus baccatus Sowerby, 1877 (figures 1-7) ? "Conus albomaculatus. Reeve"', Kiener, 1846:56, 57, pi. 83, fig. 2 (apertura! and dorsal views; as "Conus albimaculatus [sic] Sow.[erby] ), from unknown locaiit) , Dupont collec- tion. Not C. bicolor Sowerby, 1833: pt 24, fig. 2, renamed without explanation C. albomaculatus Sowerby, 1841. Conus baccatus Sowerby, 1877:753, 754, pi. 75, fig. 5, from unknown locality; Tryon, 1883: ser. 1, vol. 6, p. 22, pi. 6, fig. 92 [copy of original fig.], "Habitat unknown "; Sowerby, 1887: vol. 5, p. 251, Conus pi. 29, fig. 660 [copy of original fig.], "Habitat unknown. Coll. Meiviii"; Tomlin, 1937:217, "Hab. ?, Type in coll. Tomlin"; Coomans et a/., 1982:4, fig. 197, apertural and dorsal views of the holotype; Vink, 1984:354-358, pi. 20, fig, 1, dorsal view of holotype; Rock- el, 1985a:29, dorsal view of holotype and dorsal and aper- tural views of two recently collected specimens from "Pe- rida Island ", Pacific Panama (figured in color). Original description (in part): "Shell short, rather swol- len, very minutely decussated, with regular rows of con- spicuous granules, whitish, with large orange blotches arranged in three bands; spire acute, short, whorls con- cave, nearly smooth, last whorl biangulated. . . . Apart from its somewhat stunted form, the delicacy of its mark- ings and rows of gem-like granules, it is remarkable for the double angle at the top of the body whorl. Long. 23, lat. maj. 15 mill " [Holotype actually measures 22.2 by 14.2 mm.) Type depository: Holotype in the National Museum of Wales, no. 1955.158.29, fide Trew (1982:3); here illus- trated (figures 1, 2). Type locality: Off Isla Parida, Golfo de Chiriqui, Re- piiblica de Panama, here designated. Range: Known only from Pacific Panama. Material examined: ,\MNH Collection: From Golfo de Chiritpii, Pacific Panama: 6 specimens, no. 173698 and 8 specimens, no. 211778, off Isla Parida (8''05'N, 82°20'W), in 5.5-9 m, sand bottom. May, 1972, ex R. E. Hubert; 2 specimens, no. 210849, off Isla Parida, sand, in 5.5 m, March, 1974, ex R. E. Hubert; 3 specimens, no. 225981, off Isla de Canal de Afuera, in 55 m, ex J. Ernest; 2 specimens, no. 221871, off Isla Coiba, in 24-40 m, March 28, 1986, ex C. and P. Skoglund; 2 specimens, no. 221872, off S.E. Isla Rancheria, in 2-7.5 m, March 27, 1986, ex C. and P. Skoglund; 2 specimens, no. 223269, off Isla Rancheria (7°38'N, 81°44'W), in 3-9 m, coral sand and debris bottom, February 24, 1987, ex R. Koch. From "Panama"; 1 specimen, no. 47740, ex F. A. Constable Coll.; 3 specimens, no. 201566, ex T. H. and V. B. Mun- yan Coll. Remarks: Specimens of Conus baccatus superficially resemble small examples of the pustulose form of Conus perplexus. There are several discrete differences in shell morphology which serve to distinguish the two taxa. 1, Nuclear whorls: In C. baccatus, I'i whorls, nucleus short, terminating in a broad, well-defined mammillated pro- cess. In C. perplexus, 2'/2 whorls, nucleus elongate, nar- row, terminating in a needle-like projection (cf. figure 5 with figure 10). 2, Shoulder margin of bod\ whorl: In C. baccatus, oblique, twofold-angled (i.e., biangulated). In C. perplexus. monoangulated (cf. figures 6, 7 with figures 8, 9). 3, Spiral granulations; In C baccatus, rows of pus- tules more widely spaced, some rows weakK developed. In C. perplexus, rows consistently spaced, nearly uni- formly developed (cf. figures 6, 7 with figures 15, 16). 4, Color pattern: In C. baccatus, spiral bands of broken blotches, orange in faded specimens, reddish-broun in fresh specimens. In C. perplexus, narrow spiral lines with dark brown dots (cf. figures 1, 2 and 3, 4 with figures 8, 9). Additionally, the periostracum in C. baccatus is yel- lowish tan, whereas in C. perplexus it is a brownish tan. The largest specimen of C. baccatus examined (AMNH 221871a; figures 6, 7) is 26.9 mm in height, compared to a maximum of 37.8 mm for C. perplexus (AMNH 206684) from Isla Cebaco, Golfo de Montijo, Panama. Hanna (1963:39) reports a specimen of the latter taxon from Isla San Jose, Golfo de Panama, with a height of 41.5 mm. Both of these taxa have shells with a distinct posterior notch on the lip (cf. figure 5 with figure 10), whereas C. xirnenes Gray, 1839, C. nmhogani Reeve, 1843, and C. tornatus Sowerb\, 1833, which also have been confused with C. perplexus, have a narrow anal notch (see Wolfson, 1962: figs. 6a-d; Tucker 1985: fig. c; and Chancy, 1987: figs. 2, 3). All of these nominal species have populations sympatric with those of C. bac- catus, which is known only from Pacific Panamic waters. Conus perplexus, with which C. baccatus is most likely to be confused, ranges from the northern part of the Gulf of California, south to Mancora, Peru, 4°05'S, 81°03.5'W (LACMNH no. 70-101). Specimens of C. perplexus in which the interrupted spiral lines of brown dashes or dots are raised into prominent pustules are more commonly found in the southern populations, from Panama south- ward to Peru (figures 15, 16). .\ similar pustulose form also occurs in populations of the western .\tlantic C puncticulatus Hwass in Bruguiere, 1792, which is a twin W. K. Emerson and W. E. Sage III, 1988 Page 113 species of C. perplexus. This form was named C. pa- pillosus Kiener, 1849 (figures 17, 18). On the basis of shell morphology, C. baccatus appears to be most closely related to members of the western Atlantic C. jaspideus species complex, especially the pus- tulose, short-spired Brazilian forms which were given the names C. yemanjae (figure 19) and C. selenae by Van Mol et al. (1967: pi. 8); also figured by Vink (1984: pi. 20). Conus perplexus Sowerby (1857:20, 1858: pi. 200, fig. 324) was briefly described in Latin, followed by the com- ment; "This shell perplexes me, because there is a variety of C. puncticulalus [Hwass in Bruguiere, 1792, a Carib- bean twin species] which it nearly resembles. This, how- ever, is quite smooth, and more angular' . A single spec- imen was figured by Sowerby in a dorsal view, with the statement: "Gulf of California, West Columbia [sic], Cum.[ing]". Tomlin (1937:290) recorded the presence of three "types" in the British Museum (Naural History), which were kindh' loaned to us by Ms. K. M. Way [BM(NH) 19781 18^ here illustrated, figures 8. 9, 11-14]. The original labels confirm these specimens as syntypes, although none of them can be referred with certainty to Sowerby s figured specimen. The drawing may represent a composite. The three syntypes are somewhat faded, but are otherwise well-preserved. We have selected as the lectotype (figures 8, 9) the syntype that most closely resembles the original figure. The lectot\pe is slightly larger in height (26.8 vs. 26.1 mm) than the specimen depicted in the original illustration. The original labels accompanying the syntype lot of Conus perplexus list the Gulf of California and West Columbia [.sic], which are the same localities cited by Sowerby (1858, caption to Conus, pi. 14). Hugh Cuming is not believed to have collected in Mexican waters on his voyage to the west coast of South America, 1828-30. He is known, however, to have made extensive collections in the "Gulf of Panama, the Pearl Islands, and the Gulf of Chiriqui", as well as visits to Costa Rica, Nicaragua, and Honduras (Dance, 1986:114). We here restrict the type locality of C. perplexus to the Golfo de Panama, as the Isthmus of Panama was part of Colombia at that time. In summary, Conus baccatus G. B. Sowerby III, 1877, is recognized as a Panamic faunal constituent and as a twin species of C. jaspideus Gmelin, 1791, from the western Atlantic, especially the pustulose form named C. yemanjae Van Mol et al., 1967. Conus baccatus is compared with pustulose specimens of the sympatric C. perplexus G. B. Sowerby II, 1857, with which it has been confused, as well as with pustulose specimens of C. punc- ticulalus Hwass in Bruguiere, 1792, a Caribbean twin species of C. perplexus. A lectotype is selected and the t\pe locality is restricted for C. perplexus. A type locality is designated for C. baccatus. ACKNOWLEDGEMENTS We are indebted to Carol Skoglund and Bob Koch, Phoe- nix, Arizona, for sending us comparative material, for their observations on the differences in the nuclear whorls of Conus perplexus and the specimens which were found to be referable to C. baccatus. Their interest and coop- eration, past and present, are greatly appreciated. We acknowledge with thanks the assistance of Philippe Bouchet, Museum National d'Histoire Naturelle, Paris; Helen DuShane. Whittier, California; James Ernest, Bal- boa, Repiiblica de Panama; R. M. Filmer, Chobham, England; Robert A. Foster, Santa Barbara, California; Barbara Good, San Diego, California; James H. McLean, Los Angeles County Museum of Natural History; P. Gra- ham Oliver and Alison Trew, National Museum of Wales, Cardiff; Donald R. Shasky, Redlands, California; Kay C. Vaught, Scottsdale, Arizona; and K. M. Way, British Mu- seum (Natural History), London, for the loan of speci- mens and/or photographs, or for providing information. We also are indebted to Alan Kohn, University of Wash- ington for providing data on the complicated nomen- clatural history of the taxa Conus bicolor and C. albo- maculatus. Stephanie Crooms, AMNH, word-processed the manuscript. We owe a special debt of gratitude to Henry W. Cha- ney, Santa Barbara Museum of Natural History; James H. McLean; and James Nybakken, Moss Landing Marine Laboratories, for critically reading drafts of the manu- script. LITERATURE CITED Born, I. von. 1778. Index rerum naturalium Musei Cesarei Vindobonensis. Pars prima, Testacea. Vienna, xlii + 458 p., 1 pl. Bruguiere, J,-G. 1792. Cone. In: Encyciopedie methodique. Historie Naturelle des Vers 1:586-757, illus. Chaney, H. W. 1987. A comparative study of two similar Panamic cones: Conus ximenes and Conus mahogani. The Veliger 29(4):428-436, 6 figs. Coomans, H. E., R. G. Moolenbeek, and E. Wils. 1979. Al- phabetical revision of the (sub)species in Recent Conidae 2. adansoni io atbuquerquei. Basteria 4;3(5-6):81-105, figs. 26-50. Coomans, H. E., R. G. Moolenbeek, and E. Wils. 1982. Al- phabetical revision of the (sub)species in Recent Conidae. 5. baccatus to byssinus, including Conus brettinghami nomen novum. Basteria 46(l-4):3-67, figs. 172-292. Dance, S. P. 1986. A history of shell collecting. E. J. Brill, Leiden, xv -I- 265 pp., illus. Gmelin, J. F. 1791. Systema naturae per regna tria naturae, 13th ed. 1(6), cl. 6, Vermes. Leipzig, p. .3021-3910. Gray, J. E. 18.39. Molluscous animals and their shells. In: F. W. Beechey. The zoology of Capt Beechey's Voyage . . . to the Pacific and Behring's Straits in His Majesty's ship Blossom. . . . London, p. i-xii -I- 103-155, pis. 33-44. Hanna, G D. 1963. West American mollusks of the genus Conus — II. Occasional Papers of the California Academy of Sciences 35:103 p., 4 text figs., 11 pis. Kiener, L.-C. 1846[-48], 1849[-.50]. Species general et ico- nographie des coquilles vivantes. Vol. 2, Conus. Paris, p. 1-379, 111 pis. [Conus alhomaculatus, 1846, pp. 56, 57, pl. 83, fig. 2; C. papillosus. 1849, p. 271, pl; 72, fig. 4] Mol, J.-J. Van, B. Tursch, and M. Kempf. 1967. Resultats scientifiques des campagnes de la 'Calypso' 32. Campagne Page 114 THE NAUTILUS. \ol. 102, No 3 de la Calypso au large des cotes atlantiques de I'Amerique de Sud (1961-1962) 16. Mollusques Prosobranches; les Conidae du Bresil. Annales de I'lnstitute Oceanographique Monaco 45(2):233-254, 6 pis. Reeve, L. 1843. Conchologia iconica, \ ol 1 London Conus. London, 47 pis., with text. Reeve, L. [184S-]1849. Conchologia iconica, \'ol. .5. Conus, emendations, London, 7 p., 9 pis , with te.xt. Rtickel, D. 1985a. Conus Imccatus Sowerby III, 1877, a for- gotten valid species from tropical west-America. La Con- chiglia, Rome, yr. 17, nos. 192-193, p. 29, 8 figs. Rockel, D. 198.5b. Die Familie Conidae, nr. 22 [Contis lito- glyphus Hwass in Bruguiere, 1792]. Privately issued, 1 p., 4 figs Shaw, H. O. N. 1909. On the dates of issue of Sowerby s "Conchological Illustrations." from the cop\ presented to the Radcliffe Library. Oxford. Proceedings of the Mala- cological SocietN of London 8(6):333-340. Sowerby, G.B., I. 1833[-40], 1841. Conchological illustrations, Conus, pt. 24, fig. 2 [published March 29, 1833]; list for Conus section, p. 1-4 [published in 1841]. London. [See Shaw, 1909:340] Sowerby, G. B., II. 1857-58. Thesaurus conchyliorum. Vol. 3, pts. 17, 18. London, pp. 1-24, pis. 187-195, 196-210. [Description of Conus perplexus, 1857, p. 20; 1858, pt. 18, pis. 196-210; figure of C. perplexus, 1858, pi. 200, fig. 324, Conus pi 14] Sowerby, G. B., III. 1877. Descriptions of six new species of shells from the collections of the Marchioness Paulucci and Dr Prevost. Proceedings of the Zoological Society of Lon- don, for 1876, p. 752-755, pi. 75. [Issued Jan. 4, 1877] Sowerby, G.B., III. 1887. /n.G. B. Sowerby II (ed.). Thesaurus conchyliorum. Second supplement to Monograph of the genus Conus, Vol. 5, pt. 44 London, p 249-279, pis. 507- 512, Conus pis. 29-36 [Conus baccatus, p. 251, pi. 507, fig. 660, Conus pi. 29. Issued July. 1887] Tomlin, J R le B. 1937. Catalogue of Recent and fossil cones. Proceedings of the Malacological Societ) of London 22(4- 5):205-330. Trew, A. 1982. The .Melvill-Tomlin Collection, part 10, Co- nacea (Conidae). Handlists of the Molluscan Collections in the Department of Zoology, National Museum of Wales, Cardiff, Ser. 1:1-28 + i-ix. ' Tryon, G. W., Jr. 1883[-84]. Manual of concholog>, Ser. 1, Vol. 6, family Conidae, pp. 1-1.50, 31 pis. [Part 21, pp. 1- 64, Dec. 27, 1883] Tucker, J. K. 1985. Conus ximenes Gra\, 1839, Conus ma- hogany [sic] Reeve, 1843 and friends. Shells and Sea Life 17(8):201-202, figs, a-e, 1-5. Bayside, California. Vink, D. L. N. 1984. On the identity of Conus anaglypticus, Conus baccatus, Conus selenae and Conus yemanjae. Journal of Concholog\. London 31(6):353-.358, pi. 20. Walls, J. G. 1979 Cone shells, a synopsis of the living Conidae. T.F.H. Publications, Inc., Neptune Cit\. NJ, 1011 p, illus. Wolfson, F. H. 1962. Comparison of two similar species of Conus (Gastropoda) from the Gulf of California. Part 1: a statistical analysis of some shell characters. The Veliger 5(l):23-28, 6 figs. THE NAUTILUS 102(3):115-122, 1988 Page 115 References to Molluscan Taxa Introduced by Linnaeus in the Systema Naturae (1758, 1767) Kenneth J. Boss Miiseuiii of Comparative Zoology Harvard liniversity Cambridge, MA 02138, USA ABSTRACT Bibliographic documentation is provided for the more than 90 published resources utilized by Linnaeus as citations for mol- lusks in the 10th and 12th editions of his Systema Naturae. INTRODUCTION Linnaeus's 10th edition of the Systema Naturae of 1758 is the cornerstone of our system of binominal nomencla- ture in zoology. Many species of mollusks were described therein, and these have been the subject of individual investigations such as revisions of particular taxa as well as studies of the specimens themselves (Hanley, 1855; Dodge, 1952-59; Dance, 1967). Linnaeus also attempted to apply the binominal meth- od to the references that accompanied his treatment of the species. If he cited a reference that previously men- tioned or figured the species under discussion, he usually gave an abbreviated citation, which frequently embod- ied a shortened name of the author and that of the in- dividual work. Many of these are readily apparent to someone with a knowledge of the pre-Linnaean litera- ture; thus, "Gault. test." may be easily recognized as being a reference to Gaultieri's Index Testarum Con- chyliorum of 1742; others are more enigmatic. Some years ago I thought that it might be interesting to decipher these puzzling references in Linnaeus's Sijs- tema, both the 10th (1758) and 12th (1767) editions (the nth is a reprint of the 10th), much like Wheeler (1979) has done for fishes. However, in correspondence with the late Professor A. Myra Keen, I found that both she and Dr. S. S. Berry also had an interest in this problem. Professor Keen sent me a short draft of some 30 titles that she had connected with Linnaeus's abbreviations, and I supplied her with several that she had been unable to find. Eventually, she published a narrative account of certain authors whom Linnaeus had cited (see Keen, 1983a, b). In these papers, she noted that Linnaeus used about 40 different references in his sections on mollusks. However, when the different citations are tallied for both soft bodied and shelled mollusks [including therefore Linnaeus's categories with their genera, Vermes: Intes- tina: Teredo, Vermes: MoUusca: Clio, Limax, Doris, Te- thijs, Scyllaea, and Sepia; and Vermes: Testacea: (all genera with the exception of Lepas and Serpula though references to the two molluscan Serpula are included)], the total exceeds 90. Dance (1967) also provided a short list of volumes personally owned by Linnaeus which were utilized in various editions of the Systema. Unknown to any of us were the studies of Professor John L. Heller, Emeritus, of the Department of Classics of the University of Illinois on various botanical works of Linnaeus (see Heller, 1983, for a collection of these articles). He provided extensive bibliographic references to similarly abbreviated citations by Linnaeus in some of his botanical works such as the Species Plantarum and the Hortus Cliffortianus. He also explicated certain particularly equivocal abbreviations used by Linnaeus in referring to various insects (Heller, 1961) and planned to finish a complete bibliographical guide to zoological works cited by Linnaeus under the proposed title Bib- liotheca Zoologica Limmeana (Heller, 1968, 1979, 1983); this work is currently in press (Heller, personal com- munication) but will contain more than a malacologist need know. Although I am separately preparing a more extensive treatment of the pre-Linnaean malacological citations including comments on subsequent editions, translations into other languages as well as annotations of the holdings of the Harvard College Library system (Boss, in prepa- ration), I present below the bibliographic abbreviations utilized by Linnaeus in ihe Systema Naturae (1758, 1767) and the full citation for each reference. Of all the ref- erences, only one remains undeciphered: Linnaeus (1758: 708, 1767:1161) referred to "Tessin. epist. 1 n. 28 Cym- bium" under Argonauta argo. This is presumed to have been a letter of Count Carl Gustaf Tessin, on whose collection Linnaeus worked. Despite a thorough check- ing of apposite sources (i.e., items in the Literature Cited as well as subsequent editions of the Systema and several classical cephalopod authorities such as Chemnitz, Ke- ferstein, Conrad, Naef, Robson, Tryon, and Ferussac- Orbigny), this reference could not be located. There are several bibliographic sources for pre-Lin- naean works, and sometimes there are discrepancies in Page 116 THE NAUTILUS, Vol. 102, No. 3 citations of the sources. These may arise due to different bibliographic methods, through error, or due to the vari- ability in the copies of pre-Linnaean works, which were not always issued in uniform copies I have relied prin- cipally on the Catalogue of the Books . . . British Mu- seum .... Soulsby (1933), Engelmann (1846), Heimann (1957), Nissen (1969), and the resources of \arious Har- vard libraries. The birth and death dates of authors have been included, mainly as listed in the British Museum Catalogue; these do not always concur with such dates given by other authors, principally Dance (1986) or Nis- sen (1969). I have utilized my own method of punctua- tion and have spelled out such words as "engraved" and "portraits" when describing the texts; I have followed standard procedure for the usage of brackets, etc., as noted in the Catalogue of the Books . . . British Museum. Further, the names of publishers or printers were added when 1 knew them. With few exceptions, which are listed as "not seen", examination oi the original publication was possible. ABBREVIATED CITATIONS UTILIZED BY LINNAEUS FOR MOLLUSKS Act. angl. 301, p. 2051 (see Breyn, 1705) Act. helv. 4. p. 212, t.9, f.21, 22 (see Hofer, 1760) Act. helv. 5. p. 283, n.4, t.3, f.25, 26 or n.5 t.3 f. 27, 28 (see Schlotterbeccius, 1762) .\ct. paris. 1710, p. 463 (see Reaumur, 1710) Act. paris. 1711, t.3, f.4,5 (see Reaumur, 1711a) Act. paris. 1711, p. 199, t.6, f.5.7. or 9 (see Reaumur, 1711b) Act. paris. 1712, p. 163 (see Reaumur, 1712) Act. Petropol. 7, p. 321, t.U, 12 (see Koelreuter, 1761) Act. Upsal. 2. p. 560, t.l52, f.4. idem or f.a. (see Bromell, 1729) Adans. sen. or seneg. (see Adanson, 1757) Aldr. exs. or exsang. or exangu. (see Aldrovandi, 1606) Aldr. ins. (see Aldrovandi, 1602) Amoen. acad. (see Amoenitates Academiae) Amoen. acad. 1, p.325 (see Balk, 1746) Amoen. acad. 3: 256 (see Odhelius, 1754) Argenv. conch, (see Dezallier d'Argenville, 1742) Barr. ic. or rar. or Barrel, icon, or rar. (see Barrelierus, 1714) Baster subs, (see Raster, 1759-65) Bell. aqu. or aquat. or Rellon. aqu. (see Belon, 1553) Blank, ins. (see Blankaart, 1688) Bocc. observ. (see Boccone, 1674) Bohads. mar. (see Bohadsch, 1761) Ronan. kirch. (see Buonanni, 1709) Bonan. recr. or recreat. or Bonann. recr. (see Buonanni, 1681, 1684) Brad, natur. or Bradl. nat. or Bradl. natur. (see Bradley, 1721) Breyn. polyth. (see Breynius, 1732) Brown, jam. (see Browne, 1756) Bruckm. cent. 2 epist. (see Brueckmann, 1743) Calceol. mus. (see Cerutus and Chiocco, 1622) Chin. Lagerstr. (see Odhelius, 1754) Column, aqu. or aquat. (see Colonna, 1606) Column, phytob. (see Colonna, 1592) (Column, purp. (see Colonna, 1616) Crew. mus. (see Grew, 1681) E.N.C. (see Francus de Frankenau, 1727) Edw. av. (see Edwards, 1758-64) Ellis cor. or corall. (see Ellis, 1755) En. svec. (see Linnaeus, 1746) Faun. svec. or En. svec. (see Linnaeus, 1746) Frisch ins. (see Frisch, 1730) Gesn. aqu. or aquat. (see Gesner, 1551-87) Ginam. adr. (see Ginnani, 1755-57) Ginan. or Ginan. adr. (see Ginanni, 1755-57) Gmelin act. petrop. vol. 3, p. 246 (see Gmelin, 1729) Gnalt. test, (see Gualtieri, 1742) Grev. mus. or Grew. mus. (see Grew, 1681) Gron. lap. (see Gronovius, 1740) Gualt. test, (see Gualtieri, 1742) Hasselq. or Hasselqv. itin. (see Hasselquist, 1757) Hasselqv. act. ups. 1750. p. 33. (see Hasselquist, 1750) Hevde .Ant. Anatome mvtulorum 1683 oct (see Heide, 1683) Imperat. nat. (see Imperato, 1599) It. gotl. (see Linnaeus, 1747) It. oel. or oeland (see Linnaeus, 1745) It. wgot. or wgoth. or wogth. (see Linnaeus, 1747) Johnst. aquat. or exsangu. (see Jonstonus, 1650-53) Jonst. aquat. (see Jonstonus, 1650-53) Kaehl. or Kaehler act. Stockhb. 1754. p. 144, t.3, f.A-E or A-F (see Kahler, 1754) Kirch, mus. (see Buonanni, 1709) Klein or Klen. ostr. (see Klein, 1753) Kratz. or Kratzenst. Regenf. (see Regenfuss, 1758) Labat. itin. (see Labat, 1722) Lederm. micr. (see Ledermueller, 1760-61) Lewenh. arcan. (see Leeuwenhoek, 1695) List. angl. (see Lister, 1678) List. angl. app. [appendices] (see Lister, 1685, under Lis- ter, 1678) List, conch, or hist, (see Lister, 1685-92[-97]) List. exer. 2 or exerc. 2 or exercit. 2 (see Lister, 1695) List, exercit. anat. 1 (see Lister, 1694) List, exercit. anat. 2 (see Lister, 1695) M.L.U. or Mus. L. U. (see Linnaeus, 1764) Mus. Ad. Fr. (see Linnaeus, 1754) Mus. Tess. or Tessin (see Linnaeus, 1753) Needham microsc. (see Needham, 1745) Olear. mus. (see Olearius, 1674) Osb. iter, or Osbeck. iter, (see Osbeck, 1757) Pet. or Petiv. amb. or amboin. (see Petiver, 1713) Pet. or Petiv. gaz. (see Petiver, 1764) Pet. mus. (see Petiver, 1695) Plane, conch, (see Plancus, 1739) Reaum. act. paris. 1712, p. 163 (see Reaumur, 1712) Regenf. conch, (see Regenfuss, 1758) Roes. ins. or in.sect. (see Roesel von Rosenhof, 1746-61) Rond. aqu. or aquat. (see Rondeletius, 1554-55) Rond. or Rondel, pise, or test, (see Rondeletius, 1554- 55) K. J. Boss, 1988 Page 117 Rumph. mus. (see Rumpf, 1705, 1711, 1741) Scheuch. Diluv. (see Scheuchzer, J. J., 1716) Scheuch. helv. (see Scheuchzer, j., 1708) Seb. or Seba mus. (see Seba, 1734-65) Sellii historia Teredinis. Traject. or Sellii monogr. ultra or Sellii Tered. (see Sellius, 1733) Sloan, jam. (see Sloane, 1696) Stobaei Diss, epist. Lund, (see Stobaeus, 1732) Strom, sondm. 173 (see Strom, 1762) Swamm. or Swammerd. bibl. (see Swammerdam, 1737- 38) Tessin. epist. 1, n. 28 (not found; apparently a letter to Linnaeus) Tournef. iter, (see Tournefort, 1717) Tulp. obs. (see Tulpius, 1739) Vallisn. nat. 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[186 Dissertations by Stu- dents of Upsala (or Uppsala) University, Linnaeus being the Praeses from June 30, 1743 to June 22, 1776] 19 vol- umes, illustrated. I'psaliae. 4to. [These are the 186 disser- tations by students of Upsala University during Linnaeus's praeses or administration from June 30, 1743 to June 22, 1776; these dissertations appeared in various editions, and also were usually individually and separately issued; Lin- naeus only cited two of these for mollusks (see Balk, 1746 and Odhelius, 1754); however, his citations utilized the pagination in the collected so-called Linnaeus Edition of the ,\moenitates ,\cademicae, volumes 1 and 3, respec- tively, cited under Balk and Odhelius (see Soulsbv, 1933: 99 ff. and Heimann, 1957:83 ff] Balk, Laurentius. 1746. Museum Adolpho-Fridericianum, quod consensu ampliss. fac. medicae in Regia Acad. Up- saliensi sub praesidio viri celeberrimi D D. 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Journal of the Society for the Bibliographv of Natural History 5(1): 76-77. Heller, John L. 1979. Bibliotheca Zoologica Linnaeana. Sven- ska Linnesallskapets arsskrift. argang 1978. Yearbook of the Swedish Linnaeus Society. Commemorative Volume. Uppsala, p. 240-264. Heller, John L. 1983. Studies in Linnaean method and no- menclature. Marburger Schriften zur Medizingeschichte, (Verlag Peter Lang, Frankfurt am Main, Bern, New York. ) 7(IX):328 p. Keen. Angeline Mvra. 1983a. (January). On Linnaeus" book- shelf. The Festivus (San Diego Shell Club) 15(1):5-15. 24 figs. Keen. Angeline Myra. 1983b (August 30). On Linnaeus' book- shelf [abstract]. .Annual Report of the Western Society of Malacologists 15:15. Linnaeus. Carolus [1707-78]. 1758. Caroli Linnaei . . . Sys- tema Naturae per Regna tria Naturae, secundum classes, ordines, genera, species, cum characteribus. differentiis, synonymis, locis . . . Editio decima reformata. Impensis Direct. Laurentii Salvii: Holmiae, Tom. 1. Animalia. p. [iv], 823. Linnaeus. Carolus [1707-78]. 1767. Caroli a Linne . . . Sys- tema Naturae per Regna tria Naturae, secundum classes, ordines. genera, species, cum characteribus. differentiis, synonymis, locis . . . Editio duodecima, reformata. Impen- Page 122 THE NAUTILUS, Vol. 102, No. 3 sis Direct. Laurentii Salvii: Holmiae, Tom. 1 Regnum Animale. Pars II. Classis V-VI, Nomina Generica. Nomina specierum propria: Nomina trivialia. Nomina trivialia Papiliomim and Phalaenarum Synonyma Termini Artis. Appendi.x Svnonvniorum. Addenda. Errata, p. 533-1327 [36]. Nissen, Glaus. 1969. Die Zoologische Buchillustration. Ihre Bibliographie und Geschichte. Band I. Bibliographie. An- ton Hiersemann, Stuttgart, p. 666. Soulsby, B. H. 1933. A catalogue of the works of Linnaeus (and publications more immediately relating thereto) pre- served in the libraries of the British Museum (Bloomsbury) and the British Museum (Natural History) (South Ken- sington). Second Edition Trustees of the British Museum, London, p. xi, 246; .\ddenda and Corrigenda, 68 p., 7 plates. Wheeler, A. 1979. The sources of Linnaeus knowledge of fishes. Svenska Linnesallskapets arsskrift. argang 1978. Yearbook of the Swedish Linnaeus Society. Commemo- rative Volume. Uppsala, p. 156-211. THE NAUTILUS 102(3):123-124, 1988 Page 123 Frederick Benjamin Isely: Biographical Sketch and Malacological Contributions Mark E. Gordon Department of Zoology University of Arkansas Fayettevi'lle, AR 72701, USA Frederick B. Isely was known primarily for his pioneer- ing research in orthopteran ecology (mainly Acrididae and Tettigoniidae) and as an educator/administrator. However, he contributed significantly to the basic knowl- edge of unionacean biology and ecology. Isely began his studies with freshwater mussels in the Chikaskia River of north-central Oklahoma during 1906. These initial observations soon expanded to include aspects of union- acean ecology, growth, migration, and distributional sur- vey of mussels within the Arkansas and Red river basins of eastern Oklahoma. In these endeavors, he was finan- cially aided through an appointment as a scientific as- sistant with the U.S. Bureau of Fisheries during the sum- mers of 1910-13. As a result, five manuscripts were published between 1911 and 1931. Isely's innovative con- cepts for ecological investigations are reflected by his discussion in the 1914 growth paper of the use and value of replicate samples and of the problems encountered using mark/recapture techniques. One such problem was predation by small bo\s interested in collecting the brass tags used to mark the mussels. The distributional survey, although funded by and conducted for the U.S. Bureau of Fisheries, was delayed in publication due to govern- ment reassessment of funding priorities — World War I. This manuscript was published independently by Isely after the war. His last malacological publication resulted from the recovery of one of the "lost" growth study specimens 15 years following the completion of that in- vestigation. Further evidence for the value of replication in research. Frederick was born June 20, 1873 of Swiss parents (Christian Isely and Elise Dubach) at Spring Grove farm near Fairview, Brown County, Kansas. His early edu- cation was gained locally, culminating with his gradu- ation in 1894 from Hiawatha Academy (Hiawatha, Kan- sas). He entered Fairmount College (now Wichita State University) in its founding year 1895. He was quite active in college activities (e.g., debate team, class president 1895-99) and sports (e.g., track, football) and was award- ed a B.S. in 1899, the first 4-year graduating class of the college. In 1909, he earned an M.S. from the University of Chicago and continued that summer with further study at the Marine Biological Laboratory. Later academic endeavors were pursued during the summers of 1929 and 1931 at the University of Chicago and University of Colorado, respectively. His teaching career began with an appointment at Franklin Rural School, Brown County, Kansas (1894- 95). Following his graduation from Fairmount College, Figure 1. Frederick B. Isely during his Trinity University years. Reproduced from a photograph given to the Department of Biology, Trinity University by Mrs. F. B. Isely (courtesy of H. D. Murray). Page 124 THE NAUTILUS, Vol. 102, No. 3 he assumed the principalship of Central School, Hia- watha (1899-1901) followed by stints as teacher of bi- ology at Wichita High School (1901-06) and University Preparatory School, Tonka wa, Oklahoma (1906-12). Equipped \s ith his M.S., he served as professor of biolog\' at Central College, Fayette, Missouri (1912-20) with so- journs during the summers of 1915-17 as instructor of biology at the L'niversity of Missouri. His administrative career was initiated with an appointment as dean and professor of biology at Ckilver-Stockton College, Canton, Missouri (1920-22) followed by his assumption of the same roles at Texas Women's College, Fort Worth (1922- 31). He returned to a strictK teaching position as pro- fessor of biology at Trinity Universit\, Wa.xahachie and later San Antonio, Texas (1931-47) where he developed the majority of his orthopteran research. He also served as department chairman from 1931 to 1946, retiring from active teaching in 1946. In recognition of his achieve- ments. Trinity University awarded him the Sc.D. honoris causa upon his retirement. Isely married Mary E. Nickerson of Clearwater, Kan- sas, on May 8, 1901. They had four children and he appears to have influenced his famiK , as he did his stu- dents; biologists continue in the famih to date. In spite of a heavy teaching load, administrative duties, and re- search, he was active in community organizations throughout his life and still managed time for personal pleasures {e.g.. camping, gardening, keeping up with the latest episodes of Joe Palooka and Little Orphan Annie). Isely was a well-loved and enthusiastic instructor in ad- dition to being an active and respected scientist. He received grants-in-aid for his orthopteran research from the National Research Council (1935, 1936) and the American Philosophical Society (1937, 1941). He was a fellow and founding member of the Oklahoma Academy of Science (secretar\ 1901-12) and the North Texas Bi- ological Society (president 1924-27); a fellow of AAAS and the Texas Academy of Science (president 1938); and a member of the Society of American Zoologists, Eco- logical Society of America, Entomological Society of America, Kansas Academy of Science, Texas Entomo- logical Society, and Texas State Teachers Association. Frederick B. Isely died December 30, 1947 still active in research. Additional information may be acquired from two memoria (Alexander, 1949; Geiser, 1949). Recently, a remnant of Isely s malacological collection was rediscovered at the Stovall Museum, University of Oklahoma (Shepard, 1982). About 450 specimens of unionids, representing 37 species remain. Some inade- quately labeled lots may also be referable to Isely. Thirty- nine specimens including seven species represent vouch- ers for the 1914 growth paper. Fourteen detached brass tags are also present. The remainder of his collection is from the 1925 distribution sur\e\. Little else of Isely's malacological material, other than some papers in the archives of the Biology Department at Trinity University (H. D. Murra\, personal communication), remain. A small malacological collection of his brother, Dwight IseK , was redisco\ered at Wichita State L'niversity (Met- calf and Distler, 1984). Further information pertaining to D. Isely may be obtained in Miner (1976) and Metcalf and Distler (1984). I thank the following people for their kind assistance in providing data for this note: Mrs. Katherine Isely McGuire and Drs. Douglas G. Alexander, Harle\ P. Brown, Donald A. Distler, Duane Isely, Charles G. Lin- coln (deceased), Harold D. Murra\-, Robert W. Pennak, William D. Shepard, and Gary D. Snell. LITERATURE CITED Alexander, G. 1949. Frederick B. Isely (1873-1947), Ento- mology News 60:29-30. Geiser, S. W. 1949. Proceedings of the forty-fifth annual meeting of the American Society of Zoologists: 3. Memorial resolutions, Frederick B. Isely 1873-1947. Anatomical Record 103:233-234. Metcalf, A. L. and D. A. Distler. 1984. Gastropods collected from eastern Oklahoma by Dwight Isely in 1911. The Nautilus 98:135-137. Miner, F. 1976, Dwight Isely 1887-1974 Journal of Economic Entomology 69:289-290. Shepard, W. D. 1982. Rediscovery of a portion of the Isely unionid collection. The Nautilus 96:8. MALACOLOGICAL BIBLIOGRAPHY OF FREDERICK B. ISELY 1911. Preliminary note of the ecolog> of the early juvenile life of the Unionidae. Biological Bulletin 20:77-80. 1914. Experimental stud> of the growth and migration of fresh- water mussels. U.S. Bureau of Fisheries Document no. 792, 26 p. 1914. Mussel streams of eastern Oklahoma. U.S. Bureau of Fisheries Economic Circular no. 9, 6 p 1925. The fresh-water mussel fauna of eastern Oklahoma. Pro- ceedings of the Oklahoma Academy of Science 4:43- 118. 1931. A fifteen vear growth record in fresh-water mussels. Ecology 12:616-619, THE NAUTILUS 102(3): 125-126, 1988 Page 125 Rediscovery of Planorhella magnifica (Pilsbry) in Southeastern North Carohna William F. Adams Environmental Resources Branch U.S. Armv Corps of Engineers P.O. Bo.x 1890 Wilmington, NC 28402, USA Andrew G. Gerberich Division of Fishes National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA Early in this century, Planorbis magnificus was de- scribed by Pilsbry (1903) from the lower Cape Fear River region of North Carolina. The type localitv for the species was given simply as "lower Cape Fear River". Bartsch (1908) correctly surmised that the species is an inhabitant of lentic environments and found it living in Greenfield Lake, a manmade impoundment lying to the south of what were then the city limits of Wilmington, NC, as well as in Orton Pond, then called Sprunt's Pond, ap- proximately 16 km south of Wilmington. Baker (1945) figured and studied portions of the anatomy of specimens collected b\' Bartsch and concluded that P. magnificus should be reassigned to Planorhella. This ta.xon repre- sents the largest known planorbid. Planorhella magnifica has not been reported since the accounts b\ Pilsbry and Bartsch and has been considered extinct by some (Opler, 1976; Imlay, 1977; Palmer, 1985). Fuller (1977) hypothesized that the species may still sur- vive in Orton Pond, a manmade pond similar to Green- field Lake in age and physiography, based on an obser- vation of large planorbid egg masses there by J. P. E. Morrison. The Greenfield Lake watershed has been almost totally developed since Planorhella magnifica was described, and now undergoes intensive management for control of nuisance algae. Management measures include appli- cation of algicides during the growing season and oc- casional drawdown during winter months. Fuller (1977) mentioned fruitless attempts by himself and others to find Planorhella magnifica in Greenfield Lake. Our in- vestigations of that lake indicate that it no longer provides a suitable habitat for this species. During July 1986, Planorhella magnifica was seren- dipitously rediscovered in Orton Pond, Brunswick Coun- ty, NC, while collecting water samples. Three living specimens were obtained in 20 minutes. Four empty shells were also collected from the drift line on the shore. During another water-sampling trip in January 1987, an attempt was made to collect live specimens for captive propagation. This effort was unsuccessful as much of the aquatic vegetation had died back. However, two more empty shells were found washed up on the shore. Our samples of Planorhella magnifica vary consid- erably in size. The maximum shell diameters of the spec- imens collected alive are 35.5, 21.5, and 16.3 mm. Vouch- er specimens from our collection have been deposited in the collections of the North Carolina State Museum of Natural History (NCSM P468-P471) and the National Museum of Natural History (USNM 857935). Because of restricted access, additional trips to Orton Pond have not been made. Live specimens of Planorhella magnifica were found on the stems and undersides of the floating leaves of Spatterdock, Niiphar liiteum (Sibthorp & Smith, 1809), and Fragrant Waterlily, Nymphaea odorata (Aiton, 1789). Water depth where living specimens were collected was approximately 1 meter, and the bottom substrate was organic. Orton Pond closely matches Bartsch's (1908) description of habitat suitable to P. magnifica in Green- field Lake. Like Greenfield Lake, Orton Pond is a manmade im- poundment. Both were created early in the last century to serve as a fresh-water source for rice agriculture. Orton Pond exemplifies a type of lentic waterbody unique in southeastern North Carolina. Although blackwater lakes and ponds in the region typically are acidic, Orton Pond's waters have a circumneutral pH, ranging from 6.2 through 7.9 (Smock and Lenat, 1978). We suspect that Orton Pond may have a direct connection to waters of the Castle Hayne aquifer, an Eocene limestone deposit. The molluscan fauna of Lake Waccammaw (Columbus County, NC), the only other sizable circumneutral-pH waterbody in the region, has been investigated frequent- ly (Fuller et al, 1976; Porter, 1985), but Planorhella magnifica has not been found in that system. Lake Wac- camavv differs from Orton Pond in being much larger, a natural waterbody, and is not a blackwater system. The owners of Orton Pond undertake little manage- ment of the pond and manage the lands that surround it for timber and wildlife. With a continuation of this type of management, the near future for Planorhella magnifica seems secure. However, not all of the pond s watershed is protected in this way. Therefore, potentially adverse developments could occur quite some distance from the pond. Because of the apparent uniqueness of the waters of Page 126 THE NAUTILUS, Vol. 102, No. 3 Figure 1 . Shells of Planorbella magnifica collected alive from Orton Pond, Brunswick County, North Carolina, July 1986 (apprcximately natural size). Orton Pond and absence of Planorbella magnifica in Greenfield Lake and Lake W'accamaw, it appears that the species is extremely restricted in distribution and can be found today only in Orton Pond. We believe that any changes in the quality of the surface waters in Orton Pond's drainage basin or in its underlying groundwater regime may have a deleterious effect on P. magnifica. Due to the uncertainty of the future of the pond, an in- depth study of the autecology of the species is needed so that potential conservation measures can be developed and implemented should they prove necessary. LITERATURE CITED Baker, F. C. 1945. The molluscan family Planorbidae. Uni- versity of Illinois Press, Urbana, p. 1-530. Bartsch, P. 1908. Notes on the fresh-water mollusk Planorbis magnificus and descriptions of two new forms of the same genus from the southern states. Proceedings of the United States National Museum 33:697-700. Fuller, S. L. H. 1977 Freshwater and terrestrial mollusks. /n: Cooper. J. E . S S Robinson, and J B Funderburg (eds. ). Endangered and threatened plants and animals of North Carolina. North Carolina State Museum of Natural His- tory, Raleigh, p. 143-194. Fuller, S. L. H., M. J. Imlay, and J. D. Williams. 1976. En- dangered or threatened fresh-water mussels (Mollusca: Bivalvia; Unionidae) of the Waccamaw River basin of the Carolinas. Association of Southeastern Biologists Bulletin 23:60. Imlay, M. J. 1977. Competing for survival Water Spectrum 9:7-14. Opler, P. A. 1976. The parade of passing species: a survey of extinctions in the U.S. Science Teacher 43(9):30-34. Palmer, S, 1985. Some extinct molluscs of the U.S.A. .Atala 13(l):l-7. Pilsbry, H. A. 1903. The greatest American Planorlns. The Nautilus 17:75-76. Porter, H. J. 1985. Rare and endangered fauna of Lake Wac- camaw, North Carolina watershed s\ stem, \'ols. 1 and 2. North Carolina Endangered Species Restoration: Job Title No. VI-7. North Carolina Wildlife Resources Commission, Raleigh, p. 1-358. Smock, L. A. and D. R. Lenat. 1978. Preliminary stud\ of the effects of salt water intrusion on the macrobenthic community of Orton Pond, North Carolina. U.S. Army Engineer District, Wilmington, p. 1-48. THE NAUTILUS 102(3):127-128, 1988 Page 127 Bite by Octopus joubini: A Case Report Donald M. McKinstry Division of Science, Engineering, and Technology The Pennsylvania State University at Erie The Behrend College Erie, PA 16563-1200, USA While octopuses are capable of delivering toxic bites, human case reports are scarce (Halstead, 1978). This report describes a bite by Joubin's octopus (Octopus jou- bini Robson, 1929) in a 12-year-old boy. The incident occurred on Sanibel Island, Florida, on January 2, 1987 at about 0900. A storm had deposited a variety of marine animals on shore from the Gulf of Mexico. Not realizing that octopuses are venomous, the boy, Patrick Reed McKinstry, picked up a small specimen and was prompt- ly bitten on the dorsal surface of the right thumb prox- imal to the interphalangeal joint. He pulled the octopus away from his thumb within 10 seconds. The actual bite, described as a "sharp pinch", was quickly followed by a burning sensation of greater intensit% than a bee-sting. A tiny red spot surrounded by a white circular area 6 mm in diameter was then noticed. Bleeding was minimal, a few small drops. Over the next se\ eral hours the thumb became moderately swollen and felt sore, stiff, and, at times, somewhat numb. These symptoms, to a lesser de- gree, extended to the wrist. Medical attention was not sought because only local effects, which gradually di- minished by day one, were noticed. By day three, the thumb was slightly swollen, reddened, and sore, and a tiny hole was noticed at the site. Over the next several days, the thumb became itchy and was treated with 3% hydrogen peroxide solution. This was the first treatment of the bite. By day eight, the swelling and redness had disappeared but some soreness in the metacarpopha- langeal joint was experienced. The hole had enlarged to 2 mm in diameter and displayed a slightly irregular border. During the period up to day 12, the hole became darker and a red circular area of up to 7 mm in diameter developed around it. Itching continued but soreness in the joint area decreased. On day 12, a small amount of clear yellow fluid oozed from the hole. The area was then treated with hydrogen peroxide solution and anti- biotic ointment. The signs and symptoms gradually di- minished, and by day 32 the hole was replaced by a slightly indented circular scar 1 mm in diameter, sur- rounded by a slightly darkened firm area 6 mm in di- ameter. By da\- 100, onK' the indented scar was evident and the wound was considered completeK healed. .A shiny, hard circular scar, 1 mm in diameter, was still evident by 1 year. While in excellent health, Patrick is allergic to hymenopteran venoms and to penicillin. How- ever, this was his first exposure to octopus venom, thus, an allergic reaction to explain the bite effects was dis- counted. Secondary bacterial infection could have con- tributed to the effects experienced, however, signs of infection, e.g., pus, lymphangitis, and fever, were not observed. The octopus died after about 2 hours in a pail of sea water and was preserved in 70% isopropyl alcohol. It was identified as a nearly reproductively mature male spec- imen of O. joubini by Dr. Ronald Toll. This species, the smallest of the western Atlantic octopuses, ranges from southern Florida to the Bahamas and the West Indies. Specimens are often washed ashore by storms on the Gulf coast of Florida (Meinkoth, 1981). The dorsal surface of the specimen is deep tan, while the arms and ventral surface are light tan. The mantle is 3.2 cm in length. I have donated this specimen to Dr. Toll s collection. Two accounts of envenomation following the bite of O. joubini were found. In the first (Anonymous, 1965), a physician was bitten on the finger while handling a specimen washed ashore on Sanibel Island, Florida. He experienced a "sharp" bite with a little bleeding, quickly followed by '"the most excruciating pain which rapidly became almost intolerable." Within a few hours, the finger became very swollen, hard, and deep red. By the next day, the inflammation and pain had extended to the hand. Later, some white discharge was noted from the bite wound. The swelling and hardness gradually subsided over a period of 2 months. The only systemic effect was a mildly elevated temperature. He noted that "there was never any evidence of bacterial invasion or infection, only an extreme degree of cellulitis. ' The second case (Wittich, 1968), occurred on a re- search vessel off Egmont Key, Florida. A Florida Board of Conservation worker was bitten on the back of the hand while sorting marine specimens. In this case, '"a sharp, piercing sensation " was felt, and a "severe pain" extended to the upper arm. The bite wound bled slightK and almost instantK became surrounded by a "'pure white Page 128 THE NAUTILUS, Vol. 102, No. 3 welt of about 25 mm diameter." In the following hour, the victim experienced pain and sw elling around the bite, accompanied by nausea, headache, and fever. Improve- ment gradually occurred, but after 3 days the area was still sensitive and swollen. The swelling persisted, and some itching and a serous discharge from the wound occurred. After 1 month, a 2 mm wound surrounded by a 6 mm red periphery was present. The wound then healed quickK. In the case I report, the bite effects were not as severe as those noted above even though the victim was a child with less tissue mass to dilute the venom. However, the amount of venom delivered could have been minimal. ACKNOWLEDGEMENTS I am grateful to the following for their helpful assistance and suggestions: Ronald Toll, The L'niversity of the South, Sewanee, TN; Sherman A. Minton, Jr , Indiana Univer- sit\ , School of Medicine, Indianapolis, IN; Harry N. Cun- ningham, Jr., Kath\' Mauro, and Robert Rose, all of The Pennsylvania State University at Erie, The Behrend Col- lege, Erie, PA. A special thanks is due Patrick R. Mc- Kinstrv for his account of the octopus bite. LITERATURE CITED .\nonymous. 1965. Florida octopus bite. Sea Secrets 9(7):5. Halstead, B. W 1978. Poisonous and venomous marine animals of the world The Darwin Press, Princeton, NJ, 1043 p. Meinkoth, N. A. 1981. The Audubon Society field guide to North American seashore creatures. .\if red .\. Knopf, New York, NY, 799 p. Wittich, A. C. 1968. Account of an octopus bite. Florida Academy of Science Quarterly Journal 29l4):265-266. THE NAUTILUS 102(3):129, 1988 Page 129 Occurrence of Mites in Mexican Land Snails 0§car J. Polaco Departamento de Prehistoria Institute Nacional de Antropologia e Historia Moneda #16 Mexico 06060, Mexico Wolfgang Mendl Lab. Acarologia Departamento Zoologia Escuela Nacional de Ciencias Biologieas Apartado Postal 42186 Mexico 11340, Mexico To date there has only been a single report (Baker, 1945) of mites infecting the mantle cavity of a land snail from Mexico (Helix pomatia Linne, 1758, an introduced species). The mite was identified as Riccardoella oude- mansi (Thor, 1932), however, the mite shown by Baker (1945) is similar to the figure published by Fain and Van Goethem (1986) for Riccardoella limacum (Schrank, 1776) (Prostigmata: Ereynetidae). This mite has been studied by several European authors (Turk & Phillips, 1946; Baker, 1970) and reported as cosmopolitan. In this note, we report findings of mites parasitizing the mantle cavities of two species of land snails of the famiK Bulimulidae and one species referable to the fam- ily Helicidae. The bulimulid Bidimulus unicolor (Sow- erby, 1833), collected in Tomas Garrido, in the state of Quintana Roo, was parasitized by Riccardoella limacum. with one protonymph and one deutonvmph collected from nearly 50 specimens of the snail. Of 79 specimens of Rhabdotus alternatus (Say, 1830), another bulimulid collected in Xicotencatl in the state of Tamaulipas, that were examined, one contained three mites of the genus Boydaia (Ereynetidae) and another contained a single specimen of Eupodes voxencollinus (Sig Thor, 1934). This is the first report of the last two mite species on land snails. Examination of other land snail species of the families Helicidae, Achatinidae, Succinidae, Oleanicidae, and Polygyridae revealed no evidence of parasitism by mites, with the exception of a single specimen of Helix aspersa (MiJller, 1774), an introduced species collected in Mexico City, which was infected with two specimens of E. vox- encollinus. As no mites were found in any Mexican land snails from the above families, the family Bulimulidae remains the only new record of a host for mites. The examined snails are deposited in the Mollusk Col- lection of the Departamento de Prehistoria, I.N.A.H., and the mites in the Acarology Collection of the Labo- ratorio de Acarologia of the E.N.C.B. We acknowledge two anonymous reviewers for their critical comments to improve this paper. LITERATURE CITED Baker, E. W. 1945. Five mites of the family Ereynetidae from Mexico. Journal of the Washington Academy of Sci- ences .35:16-19. Baker, R. A. 1970, The food of Riccardoella limacuni (Schrank) (Acari: Trombidiformes) and its relationships with pul- monate mollusks. Journal of Natural History 4:521-530. Fain, A. and J. L, VanGoethem. 1986. Les acariens du genre Riccardoella Berlese, 1923, parasites du poumon de Mol- lusques gasteropodes pulmones terrestres. Acarologia 27(2): 125-140. Turk, F. A. and S. M. Phillips. 1946. A monograph of the slug mite Riccardoella limacum (Schrank). Proceedings of the Zoological Society of London 115:448-472. THE NAUTILUS 102{3):130, 1988 Page 130 Axelella, New Name for Olssonella Petit, 1970, a Preoccupied Taxon (Mollusca: Cancellariacea) Richard E. Petit Research Associate Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA The cancellariid genus Olssonella Petit, 1970, was pro- posed for a rather compact and well-defined group of species from the Later Tertiary and Recent faunas of the Americas. An Eastern .Atlantic species was subse- quently placed in this genus by Bouchet and Waren (1985;263), and the morpholog\ of the type species was published b\ Harasew\ch and Petit (1984). The ta.xon has been used b\ a number oi other authors since it was proposed. Unfortunately, it has just been noted that Olssonella is preoccupied, and a replacement name is here proposed. Axelella, new name for Olssonella Petit, 1970:83. Not Olssonella Glibert & \'an de Poel, 1967:121. Type species, by original designation of Olssonella Petit, 1970, Cancellaria smithii Dall, 1888, Recent, Western .\tlantic. This new name honors the late A.xel \. Olsson, as did the name it replaces, and the name which makes the replacement necessary. Appreciation is expressed to Dr. Philippe Bouchet, Museum National d'Histoire Naturelle, Paris, for calling the prior use of Olssonella to m\ attention. LITERATURE CITED Bouchet, P. and A. Waren. 1985. Revision of the Northeast Atlantic bathval and ab\ssal Neogastropoda excluding Turridae (Mollusca: Gastropoda). Bollettino Malacologico, Supplemento 1:121-296 Dall, W. H. 1888. Mollusks. In: Alexander Agassiz, Three Cruises of the United States Coast and Geodetic Survey Steamer Blake 2:62-75. Glibert, M. and L. Van de Poel. 1967, Les Bivalvia fossiles du Cenozoique etranger des collections de I'lnstitut Royal des Sciences Naturelles de Belgique. \". Oligodontina. In- stitut Royal des Sciences Naturelles de Belgique, Memoires (2nd ser.') 83:1-152. Harasew ych, M. G. and R. E. Petit. 1984 Notes on the mor- phology of Olssonella smithii (Gastropoda: Cancellari- idae). The Nautilus 98(l):37-44. Petit, R. E. 1970. Notes on Cancellariidae (Mollusca: Gastrop- oda)— II. Tulane Studies in Geologv and Paleontology 8(2): 83-88. INSTRUCTIONS TO AUTHORS THE NAUTILUS publishes papers on all aspects of the biology and s\stematics of mollusks. Manuscripts de- scribing original, unpublished research as well as re\ iew articles will be considered. Brief articles, not exceeding 1000 words, will be published as notes and do not re- quire an abstract. Notices of meetings and other items of interest to malacologists will appear in a news and notices section. Manuscripts: Each original manuscript and accompa- n\ ing illustrations should be submitted in triplicate. 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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 I'niversity Columbus, OH 43210 Dr. Ruth D. Turner Department of Mollusks Museum of Comparative Zoolog\ Harvard University Cambridge, MA 02138 Dr Geerat J. \ermeij Department of Biology I'niversity of Maryland College Park, MD 20740 Dr. Gilbert L. Voss Division of Biology and Living Resources Rosenstiel School of Marine and .Atmospheric Science L'niversity of Miami 4600 Rickenbacker Cau.sewav Miami, FL 33149 SUBSCRIPTION INFORMATION The subscription rate per volume is US $20.00 for individuals and US $30.00 for institutions. Postage outside the L'nited States is an additional US $2.00 for surface and US $10.00 for air mail. All orders should be accompanied by pa\nient and sent to: THE NAUTIIAS, P O. Box 3430, Silver Spring, MD 20901. Change of address: Please inform the puhlislier 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, 8911 .\lton Parkway, Silver Spring, MD 20910. 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 THEt^NAUTILUS CONTENTS Volume 102, Number 4 December 21, 1988 ISSN 0028-1344 Nidia S. Romer Donald R. Moore A new species of Alvania (Rissoidae) from the West Indian region 131 Charles N. D'Asaro Micromorphology of neogastropod egg capsules 134 Philippe Bouehet Two new species of Metula (Gastropoda: Buccinidae) with a description of the radula of the genus 149 Kurt Auffenberg Harry G. Lee A new species of intertidal Terebra from Brazil 154 Douglas C. Smith Notes on the biology and morphology of Margaritifera hemheli (Conrad 1838) (Unionacea: Marearitiferidae) 159 Alan R. Kabat Richard E. Petit The two printings of J. F. Gmelin's Systema Naturae. 13th Edition (1788-96) 164 Marine Biological Laboratory LIBRARY JAN 3 1989 Woods Hole, Mass. THE NAUTILUS 102(4):131-133, 1988 Page 131 A New Species of Alvania (Rissoidae) from the West Indian Region Nidia S. Ronier Donald R. Moore Rosenstit'l School of Marine and Atmospheric Science l'niversit> of Miami 4600 Bickenbacker Causeway Miami, FL 33149, USA ABSTRACT Alvania (Alvania) colombiana new species was found from 45 to 261 m (24 to 143 fms) depths off the Caribbean coast of Colombia to South Florida, the Gulf of Mexico, and Puerto Rico. Alvania colombiana differs from Rissoa xanthias (Wat- son, 1886), in having a protoconch with a single spiral zig-zag line of tiny nodules just above the suture, and by its smaller shell size. Alvania colombiana also differs from Rissoa precip- itata (Dall, 1889), by its protoconch and size. INTRODUCTION Exploration of the deep sea a century ago was the equiv- alent of the space age today. The famous "Challenger" expedition sampled two offshore stations in the tropical western Atlantic in which small mollusks were numerous. These were described by Watson (1886). Among the Rissoidae were two species, Rissoa pyrrhias (Watson, 1886) and Rissoa xanthias (Watson, 1886), that were similar in size and shape. Dall (1889), reporting on the "Blake" material, described two more species of Rissoa, Rissoa acuticostata and Rissoa precipitata. Rissoa acu- ticostata was similar to Rissoa xanthias. and finally Dall (1927) acknowledged that with more specimens it was impossible to separate the material into two species. Ris- soa precipitata, on the other hand, is known principally from the original description and illustration. There is another small western Atlantic rissoid which at first glance appears similar to the illustration of Rissoa precipitata. However, there are a number of features that differentiate them. Size is one: the small species has an average adult size of 1.2 mm while Rissoa precipitata (holotype) has an adult size of 3.92 mm. Protoconch is the other: the small species has a projecting protoconch while Rissoa precipitata has a depressed protoconch. One of us (D.R.M) had obtained specimens of the small species during the MAFLA (Mississippi, Alabama, and Florida) study (1974 to 1975) in the eastern Gulf of Mexico. This small species was first reported by one of us (N.S.R.) as Alvania sp. 1 (see literature cited; Rodriguez, 1983). ABBREVIATIONS USNM = National Museum of Natural History, Smith- sonian Institution. FSBS I = Florida Department of Natural Resources, Marine Research Laboratory, St Petersburg. MCZ = Museum of Comparative Zoology, Harvard Uni- versity. UMML = University of Miami Marine Laboratory. CNMS = Colombian Natural Museum of Science, Na- tional University, Bogota MATERIALS AND METHODS All the specimens to be photographed in the SEM were cleaned in 100% sodium hypochlorite for 2 minutes, then rinsed in distilled water twice. If the specimens still showed residual material (e.g., sand grains), they were sonicated for 60 seconds. Finally, the specimens were air dried and put on a SEM stub with double-sided Scotch tape. Alvania (Alvania) colombiana new species (figures 1, 2) Description: Shell 1.0 to 1.3 mm in length. Protoconch multispiral, glossy, light brown, with 3'/2 whorls that are sculptured with 1 spiral zig-zag line of tiny nodules just above the suture and 1 undulating line of the same nod- ules in the middle of the whorl. Nodules irregularly ar- ranged over entire protoconch. Teleoconch of approxi- mately 2 whorls, with numerous axial ribs. Adult shell translucent, very light brown in color. Axial ribs slightly curved, 26 ribs on the body whorl fading out on the base of the shell. Body whorl with a narrow spiral groove just below the suture and another 7 to 9 grooves between the periphery of the final whorl and the base of the shell. Varix terminal with a narrow extension forming outer lip of semilunate aperture. Some specimens weakly umbilicate. Page 132 THE NAUTILUS, Vol. 102, No. 4 Figures I, 2. Alvania colomhiana new species. I. Hololype, USNM miriiber 8.59339, 1.2S mm in length. 2. Protoconch, 280 x. Figures 3, 4. Rissoa xanthias (Watson, 1886), from off Miami, in the junior author's collection, 2.26 mm in length. 4. Protoconch, 220 X. Type locality: Off the west coast of Florida at 29°35'N, 87°20'06"W, depth 107.3 m. Holotype: USNM number 859339. Length, 1.28 mm. W'idtii, U.78 mm. Paratypes: One from off the west coast of Florida at 29°35'N, 87°20'06"W, depth 107.3 m, USNM number 859340; 2 from off the west coast of Florida at 28°24'N, 85°15'06"W, depth 164.6 m, FSBC I number 33113; and off the west coast of Florida at 29°49'30"N, 86°25'30"W, depth 82.3 m, FSBC 1 number 33114; 2 from off Puerto Rico at 17°53'24"N, 66°35'10"W, depth 221 m, MCZ number 297220; and off Miami at 25°47'N, 80°01'30"W, depth 137 m, MCZ number 297219; 2 from off Miami N. S. Romer and D. R. Moore 1988 Page 133 Figure 5. Drawing of Alvania precipitata (Dall, 1889), ho- lotype, MCZ 7470, 3.92 mm in length. at 25°47'N, 80°01'30"W, depth 137 m, UMML number 8349; and off Miami at 25°46'30"N, 80°00'08"W, depth 76.81 m, UMML number 8350; 2 from off the Caribbean coast of Colombia at 09°52'35"N, 75°47'25"W, depth 72 m, CNMS number ICN-MHN(MO)522; and off Miami at 25°46'30"N, 80°00'08"W, depth 76.81 m, CNMS num- ber ICN-MHN(MO)523. Distribution: This species was found in 31 samples from off the Caribbean coast of Colombia collected between 1979 and 1981. The specimens were found at depths ranging from 45 m to 261 m, but were most abundant at depths between 65 m and 160 m. Other specimens of this species were found from off the west coast of Florida, off southern Puerto Rico, and the Straits of Florida east of Miami. The bottom in almost all cases consisted of sandy mud. The species is probabK' found in these depths throughout the Caribbean, the southern and eastern Gulf of Mexico, and the Bahamas. All the specimens were found dead. Discussion: Alvania colombiana appears to be a com- mon widespread species throughout the Caribbean and adjacent areas. This is a very small compact species that should not be confused with any other in its range. Some features, however, are lacking or lost on the protoconch of some specimens. These include the fine nodules dis- tributed all over the protoconch, and the undulating line of nodules on the periphery. These features are seen only under high magnification, so are difficult to observe for routine identification. Details of the teleoconch sculp- ture, however, should be easy to make out under low power, even in a somewhat worn specimen. Alvania colombiana has been confused with Rissoa precipitata (Dall, 1889) (figure 5). This was due to the fact that specimens of Rissoa precipitata were not avail- able for comparison. The holotypc and only known spec- imen, MCZ 7470, is a thin shell v\itli no terminal varix. In fact, the sculpture fades away almost completely on the last half whorl (except for the sub-sutural tubercles). The protoconch is of the form seen in gastropods without a planktonic larval stage: large, rounded, unsculptured, and with a smooth transition from protoconch to teleo- conch. The type locality is Yucatan Strait at a depth of 640 fathoms (not 670 as is given by Dall, 1889:280). Another similar species is Rissoa xanthias (Watson, 1886) (figures 3 and 4). It, however, is about twice the size, has just over half as many axial ribs, and has a different and very distinctive protoconch. In this species the protoconch has 3'/2 whorls, in which the sutures are deep and ornamented with a line of spirally arranged vertical pustules. Just above the suture there is a wide canal whose edges are formed by an undulating line with vertical pustules equally spaced and directed downward. Each canal also has in the middle dots and small nodules randomly distributed. Watson reported it from Chal- lenger Sta. 24 off Culebra Island, 18°38'30"N, 65°05'30"W, depth 715 m, and from Sta. 122, 9°10'S, 34°49'W to 34''53'W, depth 640 m. Finally, Rissoa pyrrhias (Watson, 1886) is another sim- ilar species. It is slightly larger than Rissoa xanthias, and its spiral grooves are not confined to the base of the shell. According to Watson (1886), the protoconch has 2'/2 whorls which are scored with coarse but feeble spiral threads. ACKNOWLEDGEMENTS We are very thankful to Dr. Patricia Blackwelder and her assistant team at the SEM lab for their collaboration in the use of and picture taking on the SEM. We also thank Dr. Kenneth J. Boss for the loan of the holotype of Rissoa precipitata. LITERATURE CITED Dall, W. H. 1889. Reports on the results of dredging ... in the Gulf of Mexico (1877-78) and in the Caribbean Sea (1879-80) by the U.S. Coast Survey Steamer "Blake" . . . 29. Report on the Moilusca, part II. Gastropoda and Sca- phopoda Bulletin of the Museum of Comparative Zoology 18:1-492. pis. 10-40. Dall, W. H. 1927 Small shells from dredgings off the southeast coast of the United States b\ the United States Fisheries Steamer "Albatross" in 1885 and 1886. Proceedings of the L'nited States National Museum 70(2667);1-134. Rodriguez, (Romer) N. S. 1983. Micromoluscos recientes de la plataforma Caribe Colombiana entre Bocas de Ceniza e Isla Fuerte. Thesis, Universidad Jorge Tadeo Lozano, 247 p. Watson, R. B. 1886. Report on the Scaphopoda and Gaster- opoda collected by H. M. S. Challenger during the years 1873-1876. Voyage of H. M. S. Challenger, Zoology 15: 1-675; appendix A, 677-680; geographical distribution, 691-722; index, 723-756; pis. 1-50. THE NAUTILUS 102(4):134-148, 1988 Page 134 Micromorphology of Neogastropod Egg Capsules Charles N. D'Asaro Department of Biology L iii\ersit\ of West Florida Pensacola, FL 32514, USA ABSTRACT Egg capsule micromorphology of eight species of neogastropods {Chicoreus florifer dileclu.s. PhijHonotus pomum. Cantharus inuUangiilus, C. cancellariti.s. Conus floridanus floridensis, C. ju.spidcus stearnsi. Cranulina ovuliforniis. and Marginella au- reocincta) was studied with light microscopy hy examining very thick, toluidine blue stained sections Laminae exposed hy fracturing the sections, and their reactions to the stain, provided the characters used to describe micromorphology. The results showed that muricaceans and buccinaceans have complex but microstructurally similar egg capsules, while co- nids and marginellids have egg capsules with taxonomically distinct rnicrostructural characteristics. In the Muricacea and Buccinacea, four structural laminae of similar origin and func- tion are usually present in the capsule wall, the second from the outermost having the most complex pattern of fibers and the greatest thickness. The third outermost lamina is continuous with one or more components sealing the escape aperture. In some buccinaceans, only a trace of the third lamina exists in the wall. Four layers, including one or two mucoid plugs, close the escape aperture. Conid egg capsules differ in that they include only three structural laminae in the capsule wall and three layers, including a riuicoid plug, sealing the escape ap- erture. Microstructurc and fiber pattern in the middle lamina are probably unique to this family. Egg capsules of marginellids have a distinctive thin, dense wall not separated into laminae and lack an escape aperture closed by a mucoid plug. There is a preformed suture that fractures at hatching in the wall of most marginellid egg capsules. Ke\i words: Reproduction; egg capsules; Neogastropoda; Chi- coreus. Phyllonotiis. Cantharus, Conns, Cranulina: Margi- ncllti INTRODUCTION Encapsulation of early ontogenetic stages is typical of higher gastropods, especially neogastropods. The highly refractory, layered envelopes of carbohydrate and pro- tein are structurally and chemicalK complex (Hunt, 1971; Flower, 1973; Goldsmith et ai, 1978; Gruber, 1982; Sul- livan and Maugel, 1984). Encapsulation and the for- mation of egg masses provides protection and has con- siderable survival value (Tamarin and C^arriker, 1967; Pechenik, 1979, 1983; Abe, 1983; Lord, 1986). Although there are thousands of neogastropod species, it still has not been clearly established how the egg capsules are formed in the oviduct and ventral pedal gland. Nor is it known if a common capsular microstructurc exists in various neogastropod taxa. Macromorphology of the often species-specific egg capsules and egg masses produced by neogastropods has been studied more frequently than any other aspect of neogastropod egg encapsulation. This was illustrated in the review of prosobranch reproduction by Webber (1977), in a more recent review of egg encapsulation for all mollusks by Pechenik (1986), and in descriptive re- ports on the external structure of neogastropod egg cap- sules by Bandel (1975. 1976a,b,c, 1982) and D'Asaro (1986a). In early reports on neogastropod capsule-wall micro- morphology (e.g., .\nkel, 1937; Hancock, 1956), three or four laminae were described, including specific patterns of fibers. However, it was not established if these are structural relationships common to the species studied or to higher taxa. Fretter (1941) provided for Nttcella lapillus (Linne, 1758), Ocenebra erinacea (Linne, 1758), Nassarius reticulatus (Linne, 1758), and Buccinum un- datiim Linne, 1758 the most frequently cited descrip- tions of how these neogastropods construct, in the oviduct and ventral pedal gland, three or four lay ered capsules. To characterize the laminated egg capsule of Uro- salpinx cinerea follyensis B. Baker, 1951, Tamarin and Carriker (1967) published the first comprehensive study employing light microscopy — including polarized light — and electron microscopy. They described a capsule with four laminae composed of asymmetrical protein-like molecules bound into collagen-like matrices. They also noted that the great structural complexity of the capsular wall could only be partialh explained b\ Fretter's (1941) description of the formative process. Bayne (1968) con- ducted a histochemical study of several gastropod egg capsules, including those of Nucella lapillus, and found mucopolysaccharides in at least three capsular laminae of that species. He was one of the first to use toluidine blue for this purpose. Flower et al. (1969) and Flower (1973) described the origin and the ultrastructure of neo- gastropod capsular proteins. In another histochemical study, (Jruber (1982) described six structural layers in the capsule wall of Eupleura caudata etterae B. B Baker, 1951, and three additional layers associated with tlie escape aperture and la\ ers of albumen. C. N. D'Asaro 1988 Page 135 Table 1. Comparative micromorphology of muricacean egg capsules stained in most cases with toluidine blue (meta = meta- chromatic, mp = mucoid plug, nr = not reported, ortho = orthochromatic, pre = present, tt = two types of albumen cells in the oviduct, z = zone). Lasers Width closing Lavers ot Species of wall LI L2 L3 L4 aperture albumen Author Chicoreus florifer 64 ^m meta. meta. meta. meta. LI, mp, L3 two meta this report dilectus 4 ^m 54 ixm 2 Mm 4 Mm (mp), L4, 315 Mm Phylloiiotus po- 51 nm meta. ortho in meta. meta. LI, L3 (mp). two? meta this report imini 1-2 MITl part. 47 /um 1-2 Mm 2 Mm mp, L4, 429 Mm S'uccllu lapillus nr meta pre meta nr Li'' (mp) meta matrix Ankel, 1937; Fretter, 1941; Bayne, 1968 Urosalpinx cine- 109 Mm ortho. ortho. pre, 2 Mm ortho. outer z, dense pre Hancock, rea 30 Mm 75 Mm 2 um z, L3 or dif- fuse z, L4, 500 Mm 19.56; Tam- arin and Carriker, 1967 Ocenebra erinacea nr nr pre, two fi- brous lavers pre, mu- coid lay- er nr mp tt Fretter, 1941 Eupleura caudata nr meta, (1)* (2-5) (6?-7) meta (8) (1, 6?, 7 = two meta Gruber, 1982 ctterac mp, 8) * Ten lasers were described; possible relationships for eight are indicated in parentheses. In the most comprehensive and detailed study to date, Sullivan and Maugel (1984) used transmission and scan- ning electron microscopy, histochemistry, and poly- acrylamide gel electrophoresis to examine the egg cap- sule of Ihjanassa obsoleta (Say, 1822). They were able to determine the physical and chemical structure of the capsule wall and confirm the origin of four structural laminae in the oviducal capsule gland. A fifth, nonstruc- tural layer was identified as a product of the ventral pedal gland. Since the previous work did not consider egg capsule micromorphology in a taxonomic perspective, the pur- pose of this stud) was to describe the complex laminar structure of egg capsules from two species in each of four diverse neogastropod taxa: Muricacea, Buccinacea, Marginellidae, and Conidae. These descriptions, as well as those in a few papers with similar data, were used to compare neogastropod egg capsule micromorphology in order to determine if there is a common wall structure in the selected taxa, and indirectly, if a common mech- anism to produce neogastropod egg capsules exists. MATERIALS AND METHODS The eight species from St. Joseph Bay in northwest Flor- ida selected for study are listed in tables 1-3. Egg capsule macromorphology of each species is known (refer to the Results for citations and museum voucher numbers). Specimens for sectioning were preserved in 10% buffered seawater formalin, a fixative considered acceptable be- cause egg-capsule proteins are very stable in a range of acids and bases and are only slightly soluble when au- toclaved in water (Hunt, 1971). Capsules were taken from near the center of well-formed egg masses, or if deposited individually, they were selected to represent the average size and shape for that species. To determine the number of egg capsules per species that must be sectioned to account for possible variations in staining and micromorphology, preliminary histolog- ical procedures were performed on two egg capsules from each of five egg masses of Cantharus multangulus (Conrad, 1846) deposited by different females. Although the sectioned capsules were not microstructuralh iden- tical, a recognizable pattern of structural laminae existed among all capsules produced by the same and different females of this species. Because the pattern for C. mul- tangulus could be recognized in each sectioned capsule and the literature suggested that it existed for other neo- gastropod species, sections for the remaining seven species were prepared from only two or three egg capsules pro- duced by different females. .After fixation, the larger egg capsules were opened along one edge in the longest axis with a scalpel to ac- celerate diffusion of the embedding fluids. Following dehydration in ethyl alcohol, capsules were cleared in toluene and embedded in paraffin (melting point = 56 °C). Capsules were sectioned at 20-22 um. All sections were parallel to the longest axis and included some that passed through the sealed escape aperture and the basal plate. To separate structural laminae, the capsule wall was frac- Page 136 THE NAUTILUS, Vol. 102, No. 4 Figure 1. Schematic drawing of a longitudinally sectioned egg capsule of Cbicurciis florifer dilectiis. Figure 2. Drawing, like figure 1, of a PhijUonoius pomum egg capsule. Numbers with arrowheads indicate positions at which photo- graphs for figures 3-12 were taken. Empty spaces in figures 1 and 2 are artifacts produced during dehydration. A = adhesive, DA = dense albumen, E = embryo, IMP = inner mucoid plug, LI = metachromatic first lamina — solid line, L2 = second lamina — light stipple, L3 = metachromatic third lamina — solid line, L4 = metachromatic fourth lamina — broken line, OMP = outer mucoid plug, T.'\ = thin albumen. L2 is metachromatic in figure 1 and partially orthochromatic in figure 2. turcd and partially delaminated by varying the speed at \\ liicli the microtome blade cut a section. To demonstrate mucopolysaccharides, sections were stained with toluidine blue for 1.5-2.0 minutes according to the method of Gurr (1962:440). They were then rap- id!) delnclrated in ethyl alcohol, cleared in toluene, and mounted in methyl methacrylate. Egg capsule microstructure was examined using light microscopy. Observation of the preliminary sections sug- gested that toluidine blue metachromasia would produce a range in color from pur[)le through heliotrope (reddish purple) but rarely red. Also, some layers would be or- thochromatic (blue) or colorless. In the intact capsule wall, structural laminae were difficult to trace by follow- ing metachromatic la\ers alone. However, when a struc- tural lamina was first isolated and defined in a fractured or delaminated section, then the lamina could be rapidly and comparably traced in whole, stained sections. If a capsule fractured and delaminated repeatedK' in a con- sistent pattern, then the parts were considered distinct structural laminae produced by different types of cells or produced at different times. Those less than a few micrometers wide could be recognized when they sep- arated from the sections and folded to one side. Very thick sections also allowed microsculpture on the outer laminar surface to be examined {e.g., figure 3). Following Tamarin and Carriker's (1967) method, structural lam- inae were identified from outermost to innermost as Ll- L4. Diagrams of median sections were prepared with a drawing tube mounted on a compwund microscope, while photomicrography was used to record microstructure at selected positions on a section Measurements of the capsule wall, structural laminae, and the sealed escape aperture were taken from the middle regions of each (tables 1-3). These dimensions should be considered approximations, as Sullivan and Mangel (1984) suggested, because of possible shrinkage introduced by the method and the wide range in width occurring at approximately the same position on different capsules of the same species. RESULTS Chicoreus florifer dilectus (A. Adams, 1855) (figures 1, 3-8; table 1; USNM 860426) Egg capsules of this muricid are distinctly vasiform in section (figure 1). Macromorpholog\ was described by D'Asaro (1970:420, fig. 3). The capsules have a thick, highK fibrous wall in which four structurally distinct components can be identified: LI, a thin, fineK fibered, metachromatic outer lamina; L2, a metachromatic lamina, with layered, coarse fibers forming the bulk of the wall; L3, the thinnest meta- chromatic lamina, closely applied to the innermost layer; and L4, a metachromatic lamina surrounding the al- bumen (figures 3, 4; table 1). LI is so transparent that the coarser L2 fibers can be seen through it. Except on the stalk and basal plate, LI is folded in a corrugated maruier (figures 3, 4, os). L2 may have fibers directed at right angles or parallel to the long capsule axis and ar- ranged with regional differences in two or three fused layers. When three fibrous components are present, the middle one has the coarser fibers arranged parallel to the long axis (figure 3, L2). Where the wall was folded during formation, L2 fibers separate, forming large \acuoles (figure 4, v). These vacuoles are not stained and are probably filled with a nonmucoid liquid. L2 fibers fuse with a more or less homogeneous inner component in Figures 3-8. Sections of the Chicoreus florifer dilectus egg capsule. 3. Wall showing laminae 4. Wall just below the apical plate. 5. .Albumen fibers. 6. Mucoid plugs in the escape aperture at the junction with 1.2 7. Wall in the stalk 8. Basal plate and adhesive. Positions at which photographs were taken are indicated on figure 1. a = adhesive, da = dense albinnen, f = fracture, fl,3 = C. N. D'Asaro 1988 Page 137 w. .. - V *;^ * A*" I 'fly J -^ V . •ts %T:y ta m 50 u m • ' — I fragment of L3, fiL2 licmmm luuus component of L2, imp = inner mucoid plug, isz = intensely stained zone, LI = metachromatic first lamina, L2 = metachromatic second lamina, L3 = metachromatic third lamina, L4 = metachromatic fourth lamina, os = outer surface of LI, omp = outer mucoid plug, sL2 = outer portion of L2 in the stalk, ta = thin albumen. Page 138 THE NAUTILUS, Vol. 102, No. 4 Figures 9-12. Sections of the Phyllonotuti pnmum egg capsule. 9. Wall showing all laminae. 10. Escape aperture toward the base. 11. Escape aperture toward the ape.x 12. Stalk and basal plate. Positions at which photographs were taken are indicated on figure 2. a = albumen, cf = circular fibers, e = embryo, hL2 = homogeneous component of L2, imp = inner mucoid plug, Li = metachromatic first lamina, L2 = partially orthochromatic second lamina, L3 = metachromatic third lamina, L4 = metachromatic fourth lamina, omp = outer mucoid plug, os = outer surface of LI. sL2 = outer portion of L2 in the stalk, r = ridge. contact with L3 (figures 3, 4, hL2). L3 stains less inten- sively than L4. In the apical plate, L3 appears to fuse with the inner mucoid plug and may have similar com- position, .^s described by Ankel (1929: fig. 1) for Nucella lapilhis and Franc (1940: fig. 2) for Ocinelmna aciculata (Lamarck, 1822), L4 completely surrounds the albumen and probably contains it during assembly of the capsule while other components are more fluid. Hereafter, L4 will be called the albinnen retaining layer. Two structurally distinct types of albumen occur: an outer layer including metachromatic fibers with random- ly attached granules in which all embryos arc situated (figures I, TA; 5, ta) and, an inner core including denser strongly metachromatic fibers (figures I, DA; 5, da). Fi- bers of dense albumen ma\ fuse in a continuous layer where the albuminous components meet; however, the fused layer did not delaminate during sectioning. The thin outer albumen does not envelop the denser core basally (figure 1). The apical escape aperture is closed by a structuralh complex barrier composed of four la\ers (figures 1. 6). LI iscontiguouswith the outer layer. The metachromatic (purple) second layer or outer mucoid plug is larger than the aperture and interdigitates with but is clearly sepa- rated from the homogeneous iimer component of L2 (figure 6, omp, hL2). Fractures across the w idth of the outer mucoid plug apparently caused during sectioning occurred (figure 6, f). The third layer is a lenticular, heliotrope mucoid plug, larger than the aperture, w hich sometimes fractures during sectioning. L3 is fu.sed to the lenticular or inner plug in an intensely stained zone (fig- ure 6, isz). L4 is the innermost layer closing the escape aperture and is fused to L3 in the same intenseK stained zone. The stalk and basal plate are formed from the capsule wall and an adhesive material (figures 1, A; 7, 8, a). The outer portion of both includes LI and up to the longi- tudinal, fibrous component of L2 (figure 7, sL2), while C. N. D'Asaro 1988 Page 139 the base of the capsular lumen is formed from the re- maining parts of L2 as well as L3 and L4. Mucoid ad- hesi\e, which has orthochromatic and metachromatic zones and occasional L2 fibers, fills the center of the stalk (figures 7, 8, a). Phyllonotus pomtim (Gmelin, 1791) (figures 2, 9-12; table 1; USNM 860425) The somewhat tongue-shaped capsules and the rather massive, communal egg masses were described by Perr\ and Schwengel (1955: fig. 338), D'Asaro (1970:422, fig. 3), Radwin and Chamberlin (1973:107, fig. 1), Bandel (1976a:10, fig. 4), and Moore and Sander (1978:253, fig. 2). Unlike Chicoreus florifer egg capsules, those of Phyl- lonotus pomum may have two points of attachment w ith a supporting substratum that nearly always is a conspe- cific capsule. Sections of such capsules are very variable in outline. Phyllonotus pomum capsules have a distinctly fibrous wall that is only partially metachromatic (table 1). Four structural parts e.\ist: LI, a thin, metachromatic outer lamina; L2, a thick, coarsely fibered and partially or- thochromatic lamina; L3, a strongly metachromatic com- ponent; and L4, a metachromatic albumen retaining lay- er (figures, 2, 9). LI is as transparent as the homologous lamina in Chicoreus florifer dilectus and is corrugated on or near folds in the wall (figures 10, 11, os). L2 remains almost unstained. It has a core of longitudinal fibers bor- dered in most areas by a few circular fibers (figure 9, L2, cf). Each side of the fibrous zone may be bordered by a narrow, faintly orthochromatic, homogeneous zone (figure 9, hL2). L3 has no obvious fibers and appears fused to the outer mucoid plug of the escape aperture, as noted later. L4 has distinct circular fibers arranged in a single layer. Albumen, including fibrous and amorphous material, is present in sections only near the retaining layer (figure 10, a). This distribution is an artifact, as noted in Can- tharus cancellarius, caused by loss of the more fluid contents during dehydration. Embryos are distributed in both components of the albumen. Positioned on one side of the capsule, the sealed escape aperture includes four layers (figures 10; 11, LI, omp, imp, L4). The outer component is formed from LI. The second outermost layer, including intensely stained metachromatic regions, is continuous with but distinct from the homogeneous proximal part of L2, and appears to be fused or continuous with L3. This pattern is dif- ferent from that of Chicoreus florifer dilectus. A third layer, which is metachromatic, mucoid with small ves- icles, and exceedingly fragile, bulges into the capsular lumen, where it is bordered by L4, the albumen retaining layer. The more apical and lateral borders of the escape aperture, formed from L2, have an inward projecting ridge (figure 11, r). The basal plate is formed from LI and the outer half of L2. A separation occurs in a dense reticulum or vac- uolated zone near the midline of the lamina (figure 12, Figure 13. Schematic drawing of a longitudinally sectioned egg capsule of Canlharus multanguliis. Figure 14. Drawing, like figure 13, of a Cantharus cancellarius egg capsule. Empty spaces in figures 13 and 14 are artifacts produced during de- hydration. Numbers with arrowheads indicate positions at w hich photographs for figures 15-23 were taken. A = adhesive, .\D = apical depression, BM = basal mucoid material, D.A = dense albumen, E = embryo, LI = orthochromatic first lamina — solid line, L2 = second lamina — light stipple, L4 = metachro- matic fourth lamina — broken Une, MP = mucoid plug, TA = thin albumen sL2). Where the outer half of L2 was in contact with the substratum, a homogeneous zone having some fibers ex- tending through it toward the substratum is present. The inner half of L2, L3, and L4 form the floor of the capsular lumen. No adhesive layer was observed on capsules that had been attached to those of conspecifics. Cantharus multangulus (Philippi, 1848) (figures 13, 15-19; table 2; USNM 947143) Macromorphology of the egg capsule was described by Perrv and Schwengel (1955: fig. 340), Radwin and Cham- berlin (1973:110, fig. 6), and D'Asaro (1986a:85, fig. 3). Median sections through the ribbed and spined capsule are roughK vasiform in outline and have a rounded, apical depression partly covered by a transverse ridge Page 140 THE NAUTILUS, Vol. 102, No. 4 Figures 15-19. Sections of the Canlhartis mullai^gulus egg capsule 15. Wall showing laminae 16. Escape aperture adjacent to apical depression 17. Escape aperture on side opposite apical depression. 18. .Alliunien layers 19. Stalk and adhesive. Positions at which photographs were taken are indicated on figure 13. a = adhesive, ad = apical depression, bm = basal mucoid material, da = dense albumen, LI = orthochromatic first lamina, L2 = second lamina, L2m = metachromatic component, L2o = ortho- chromatic component, mp = mucoid plug, os = outer surface of LL ta = thin albumen. C. N. D'Asaro 1988 Page 141 Table 2. Comparative niicromorplinlogy of buccinacean egg capsules stained in c'hronialic, nip = mucoid plug, nr = not reported, ortho = orthoclironiatic, pre = oviduct) most cases with toluidine blue (mcta = meta- present, tt = two types of albumen cells in the Species Width of wall LI L2 L3 L4 Layers closing Layers of aperture albumen Author Cantharus ntul- langulus 23 iim ortho, ortho and vestige meta, 1-2 /im meta, 1-2 /tm 21 ^m Cantharus cancel- 22 fim ortho, ortho and vestige meta, larius 2 ^m meta, 3— i ^m 17 urn Btisycon carica nr pre pre pre pre and B. canalicu- latum Nassarius reticiila- nr three layers of uncertain relationship mentioned tus Buccinium undo- nr pre two fibrous mucoid nr turn layers layer Ilyanassa obsoleta 11-22 meta pre, meta, 1 ^m pre, 60 nm (LO pre) Mm 0 2 nm 9-10 ^m LI, L2, mp. two meta this report L4, 210 /im LI, L2, mp, two meta this report L4, 117 Mm nr two Harasewych, 1978 nr tt Fretter, 1941 nr tt Fretter, 1941 LI, L2, L3 nr Sullivan and (mp), L4, Maugle, 110-150 1984 Min (figure 13, AD). In the intact capsule, the depression is not obvious when viewed apically. Cantharus cancel- larius (Conrad, 1846) has similar sculpture on its apical plate (figure 14, AD). Capsules of C. miiltangulus have a wall in which the fibers appear fused in most regions when viewed with light microscopy. There are three distinct components that appear homologous to three of the four muriccacean laminae: LI, a dense, orthochromatic outer lamina; L2, a mostly homogeneous central lamina, including vacuoles in some regions and fibers in others; and L4, a retaining layer surrounding the albumen (figure 15; table 2). LI stains intensely and may appear black. L2 may have up to four layered but fused components with the outermost being metachromatic and the innermost orthochromatic. The innermost component, like LI, is intensely stained and may appear black (figure 15, L2o). L2 has somewhat tubular vacuoles in the metachromatic area, especially near the apical depression and where the wall is folded into ridges or spines (figures 16, ad, L2m; 17, L2m). L3, which in many muricaceans is continuous with a mucoid plug in the escape aperture, is not a distinctive feature in the capsule wall (see the following comments con- cerning the escape aperture). The albumen retaining layer is characteristically wrinkled when it separates from the wall (figure 15, L4). Albumen occurs in two metachromatic components: a dense portion, broadest near the apical plate, containing short, closely packed fibers with attached, irregular gran- ules, and a thinner, more diffuse portion with coarser fibers and granules, filling most of the lumen (figures 15, da; 18, da, ta). Embryos are positioned in the latter. The escape aperture is closed by four layers. LI, the outer component, is in continuous contact with the or- thochromatic part of L2 (figures 16; 17, L2o). The or- thochromatic part of L2 is somewhat folded, intensely stained, and may fracture vertically during sectioning. The broadest layer closing the aperture is a metachro- matic, mucoid plug lying between the orthochromatic part of L2 and L4 (figures 13, MP; 16, 17, mp). Apically, the mucoid plug lies between L2 and L4 in the homol- ogous position for L3 in muricaceans, but it does not extend to the base of the lumen as a continuous lamina (figure 13). However, above the stalk between L2 and L4, there is some metachromatic mucoid material with chromotropic characteristics similar to those of the apical plug (figures 13, BM; 19, bm). This mucoid material could have been formed at the same time as the plug and would be homologous to L3. L4 is the innermost layer closing the escape aperture. The stalk and basal plate are formed from LI and most of L2, while the base of the capsular lumen is formed from the orthochromatic part of L2, some mu- coid material, and L4 (figure 19, L2o, bm, L4). The stalk has a core of metachromatic mucoid adhesive (figure 19, a). Cantharus cancellarius (Conrad, 1846) (figures 14, 20-23; table 2; USNM 847140) The macromorphology of the egg capsules of this species was described by Radwin and Chamberlin (1973:110, fig. 8) and D'Asaro (1986a:84, fig. 2). Most median sec- tions of the capsules are cylindrical to vasiform in outline (figure 14). A rounded depression in the apical plate, similar to one observed in C. multangulus, is prominent and partially covered by a raised transverse ridge folded toward the escape aperture. As in C. multangulus, much of the capsule wall ap- pears to be composed of fused fibers. Three structural Page 142 THE NAUTILUS, Vol. 102, No. 4 Figures 20-23. Sections of the Cantharus cancellarius egg capsule. 20. Wall showing laminae 21. Escape aperture opposite apical depression. 22. Escape aperture adjacent to apical depression. 23. Basal plate and adhesive. Positions at which photographs were taken are indicated on figure 14. a = adhesive, ad = apical depression, bm = basal mucoid material, da = dense albumen, LI = orthochromatic first lamina, L2 = second lamina, L2m = metachromatic component, L2o = orthochromatic component, mp = mucoid plug, OS = outer surface of LI, sL2 = outer portion of L2 in the stalk, ta = thin albumen. laminae, homologous to three of the four muricacean laminae, are present. These are: LI, a very thin, ortho- chromatic outer lamina; L2, an orthochromatic and metachromatic central lamina with tubular vacuoles; and L4, a metachromatic albumen retaining layer (figure 20; table 1). LI is often denser on the apical plate. Distinct tubular vacuoles are present in the central portion of L2, especially where ridges e.xist in the wall and apical plate. Longitudinally directed vacuoles are positioned nearer to the outer surface, while more circularly directed vac- uoles are nearer to the ituier surface. Apically, where the wall is folded, fibers in the lamina are visible (figure 21). As shown for C multangulus, L3 is not present as a distinct and continuous lamina throughout the whole capsule. The metachromatic albumen retaining layer is extremely thin and can be identified only where it is pulled away from the albimien or the capsule wall and folded to one side (figure 20, L4). Dense metachromatic albumen with fine fibers surrounds more coarsely fibered, less dense albumen in which embryos are positioned (fig- ure 20, da, e, ta). The escape aperture is closed by four layers arranged in a pattern essentially identical to that of C. multan- gulus. Apically, LI forms the outermost layer (figures 21, 22). The expanded, orthochromatic part of 1,2 is the second component. It has \ertical folds or fractures (fig- ures 21; 22, L2o). The broadest component is a meta- chromatic mucoid plug lying between the orthochro- matic part of L2 and L4 (figures 21; 22, mp). This plug tapers basally between L2 and L4, but does not extend to the base as a continuous lamina equivalent to L3. There is a layer of similar mucoid material positioned between L2 and L4 at the base of the lumen (figures 14, BM; 23, bm). Basally, the plate is formed from LI and most of L2 (figures 14; 23, sL2). Only the orthochromatic, proximal C. N. D'Asaro 1988 Page 143 part of L2 extends across the base, where it, some mucoid material, and L4 form the floor of the lumen. Unlike most specimens of C. multangulus. the lumen is sepa- rated from the substratum b\ only a narrow layer of metachromatic adhesive (figure 23, a). Contis jioridanus flohdensis Sowerby, 1870 (figures 24, 26-29; table 3; USNM 847141) Median capsular sections typically have the longitudinal axis angling away from the axis of the stalk and show a slightly irregular outer surface (figure 24). Macromor- phology was described by Perry and Schwengel (1955: fig. 360, as C. spurius atlanticits Clench, 1942) and D'Asaro (1986a:88, fig. 4). The capsule wall has three distinct components: LI, a fibrous metachromatic outer lamina; L2, a finely fibered, orthochromatic central lamina; and L4, a thin, meta- chromatic albumen retaining layer (figure 26; table 3). LI is very transparent and has fibers circular in cross section. Occasional corrugations mark this lamina, es- pecially near the escape aperture and external ridges (figure 27, LI). Fibers in L2 tend to form a cross-hatched pattern in the upper three quarters of the capsule, but some align with the long axis in the stalk and the base (figures 26-29). Globular structures buried in the fibrous layer occur frequently (figure 27). No homologue of L3 is present as a distinct layer, nor is there evidence that the mucoid plug in the escape aperture is homologous to L3. The albumen retaining layer (L4) is not obviously fibrous. Although this layer is the third in sequence, it is designated as L4, the albumen retaining layer, because its position and probable function appear the same as L4 in Vluricacea and Buccinacea. in this species, only one layer of fibrous, metachro- matic albumen is visible (figure 26, al). Granules are attached to the widely separated fibers. Embryos are randomly positioned in the albumen. The sealed escape aperture is less complex than similar structures formed by muricaceans or buccinaceans. It is lined on its outer surface by LI and on its inner surface by L4. L2 is replaced by metachromatic, layered mucoid plug with which it interdigitates extensively (figure 27, mp). The degree of interdigitation suggests that L2 and the mucoid plug were formed at the same time. The stalk is composed of LI and almost all of L2 from both sides, while the basal plate on each side is composed of LI and L2 from the same side (figures 28, 29, sL2). A fibro-mucoid, metachromatic adhesive, which may ex- tend into the stalk, attaches the basal plate to the sub- stratum (figure 29, a). Fibers from L2 radiate widely into the adhesive, especially where it extends into the stalk. Conus jaspideus stearnsi Conrad, 1869 (figures 25, 30-32; table 3; USNM 847148) When sectioned, the lamellate capsules, described by D'Asaro (1986a:88, fig. 4), appear pointed at the apex with a broad stalk and an escape aperture on one side. Figure 24-. Schematic drawing of a longitudinally sectioned egg capsule of Conus floridanus floridensis. Figure 25. Drawing, like figure 24, of a Conus jaspideus stearnsi egg capsule. Numbers with arrowheads indicate positions at which photographs for figures 26-32 were taken. \ = adhesive, .\L = albumen, E = embryo, LI = metachromatic first lamina — solid line, L2 = second lamina — light stipple, L4 = meta- chromatic albumen retaining layer — broken line, MP = mucoid plug. In this plane, the basal plate is the widest part (figure 25). Three laminae were identified: LI, a finely fibered, metachromatic outer lamina; L2, a complex orthochro- matic and metachromatic lamina with fibrous and mu- coid components; and L4, a metachromatic albumen re- taining layer (figure 30; table 3). LI, with circular fibers, is tightly fused to the fibrous portion of L2. Except near the escape aperture and on the stalk, this layer is uni- formly corrugated (figures 30; 31, os). L2 has an ortho- chromatic outer component with coarse, circular fibers (figure 30, L2). The inner component of L2 consists of at least three metachromatic layers of mucoid material containing scattered fibers arranged parallel with the long axis (figures 31, 32, mL2). Of the species studied, only C. /. floridanus has a similar arrangement of fibers in mucoid material, and that occurs only in the stalk. No distinct lamina equivalent to L3 is present. L4 may have fragments of albumen fused to its inner surface (figure 32, is). Albumen in this species is metachromatic and includes scattered transparent spherules and irregular granular material that may form layers (figures 30-32). Embryos are distributed throughout it. Page 144 THE NAUTILUS, Vol. 102, No. 4 LI n. Figures 26-29. Sections ot the Conu:> jioridanm floridensis egg capsule. 26. Wall showing laminae. 27. Escape aperture. 28. Stalk 29. Basal plate and adhesive. Positions at which photographs were taken are indicated on figure 24 \ = adhesive, al = albumen, is = inner surface of L4, LI = metachromatic first lamina, L2 = orthochromatic second lamina, L4 = metachromatic albumen retaining layer, mp = mucoid plug, as = outer surface of LI, sL2 = outer portion of L2 in the stalk. Table .'{. Comparative micromorphology of conid and marginellid egg capsules stained in most cases with toluidine blue (meta irutai hromatic. mp = mucoid plug, ortho = orlhochromatic. pre = present). Species Width of wall LI L2 L.3 L4 Lasers closing aperture Layers of albumen Author Conus floridanus 49 ^m meta, floridensis .5 nm Conus jaspidius 25 niu meta, slearnsi 2-3 Mm Granulina ovuli- formia \r> fim Marginella aureo- 12 ^m cincta ortho, not pre 40 M'li ortho and not pre meta, 22 nm one lamina present one lamina present meta, LI, mp, L4, one meta 3-4 nn\ 330 ^m meta, I.I, mp. L4. one meta 1-2 ^m I N ^m suture in wall two meta suture? two meta this report this report this report; D Asaro, 1986 this report; D'.Asaro, 1 9.Sfi C. N. D'Asaro 1988 Page 145 LI forms the outer covering of the escape aperture, w hile the inner lining is L4. A metachromatic, mucoid plug replaces L2 (figure 31, mp). The edges of the mucoid plug are separated from L2 b> an interdigitating meta- chromatic boundary zone, similar but less complex than that of C. /. floridensis. None of the scattered fibers in the metachromatic mucoid layers of L2 enter the mucoid plug. The two outer laminae form the stalk and basal plate, w hile the base of the capsule is composed of the albumen retaining layer and the inner, mucoid part of L2 (figure 32, mL2). The stalk varies in length; therefore, in some specimens the lumen of the capsule may be nearly level with the substratum. A dense mucoid adhesive is present basalK (figure 32, a). Granulina ovuUjormis (Orbigny, 1841) (figure 33; table 3; USNM 836973) Macro- and micromorphology of the egg capsules, based in part on eosinophilic features, were described by D'Asaro (1986b: 196, figs. 3-5). Because of structural differences, marginellid capsule micromorphology is not describable with reference to Tamarin and Carriker's (1967) system of enumerating capsule laminae. The simple, pustulate capsules are constructed from an inner component, enclosing two layers of albumen and an embryo, and basement and outer components that sandwich and fuse the previously mentioned struc- ture between them (D'Asaro, 1986b). Because these com- ponents were uniformly unstained and did not delami- nate during sectioning, the capsule wall is defined as having a single structural lamina of uniform composition, possibK formed by the same portion of the oviduct that produced the layers of L2 in muricaceans and bucci- naceans (figure 33, cw). The outer surface of the capsule is coated with metachromatic mucus. No escape aperture with a mucoid plug exists. The point at which the capsule wall fractures at hatching is marked by a distinct meta- chromatic suture (figure 33, s). Dense granular albumen lies just below the capsule wall, while a less dense com- ponent immediately surrounds the single embryo. Both albuminous layers stain metachromatically. The adhesive on the basal layer is not stained (figure 33, a, bl). Marginella aureocincta Stearns, 1872 (figure 34; table 3; USNM 836974) Macro- and micromorphology of the egg capsule were described by D'Asaro (1986b: 195, figs. 3-5). 'With ap- plication of toluidine blue, all parts of the capsule are metachromatic, except the unstained basement adhesive. The capsule wall does not delaminate and stains intensely to the point of obscuring its layered structure suggesting that, as in Granulina ovuliformis, it should be defined as a single structural lamina (figure 34, cw, osw). Dis- tinctive granulations, described by D'Asaro (1986b: 195, fig. 3), are obvious on the outer surface. No specific fibrous layer surrounds the albumen. The metachro- matic, finely granular albumen occurs in two compo- Figures 30-32. Sections of the Conus jaspideus stearnsi egg capsule. 30. Wall showing laminae 3 1 . Escape aperture toward apex. 32. Stalk, basal plate, and adhesive. Positions at which photographs were taken are indicated on figure 25. a = ad- hesive, al = albumen, is = inner surface of L4, LI = meta- chromatic first lamina, L2 = orthochromatic and metachro- matic second lamina, L4 = metachromatic albumen retaining ia\er, mL2 = mucoid component of L2, mp = mucoid plug, OS = outer surface of LL Page 146 THE NAUTILUS, Vol. 102, No. 4 Figure 33. Section of the GranuHna ovitlifurmis egg capsule attached to a Thalassia leaf. Figure 34. Section of the Marginella aureocincta egg capsule, a = adhesive, bl = basement layer, cw = capsule wall, da = dense albumen, osw = outer surface of capsule wall, s = suture, ta = thin albumen. nents, a narrow band of dense material and a more fluid, central zone in which the embryo lies (figure 34, da, ta). DISCUSSION Separation of structural laminae by fracturing and to- luidine blue staining allows differentiation and identifi- cation of homologous components of neogastropod egg capsules. Laminae can be identified in this manner be- cause the fibers of which they are composed appear to have been secreted and chemically bound together dur- ing separate phases of assembly. Separate or combined functions related to protection, structural support, release of larvae or juveniles, and albumen retention are inferred for the structural laminae. ,\mong the iieogastropods studied, three microstruc- tural patterns of laminae were identified, each charac- terizing specific higher taxa. Complex, four-layered cap- sules with an escape aperture sealed by four layers, including two that are mucoid, were found in nearly all muricaceans and buccinaceans examined. Three-layered capsules having an escape aperture sealed by three layers, including one that is mucoid, were found in the Conidae. Uncomplicated, single-layered capsules that may only have a suture in the wall to facilitate hatching appear to be characteristic of the Marginellidae. Muricacea and Buccinacea are species-rich taxa hav- ing family or species-specific egg capsule morphologies with a final shape that results from a molding process in the ventral pedal gland (.Ankel, 1929; Gruber, 1982; Sul- livan and Maugcl, 1984). Micromorphological similari- ties suggest that oviducal mechanisms common to both superfamilies are u.sed to construct structural laminae that serve the same respective functions in these taxa (tables 1, 2). Some species may add additional nonstruc- tural layers in the ventral pedal gland (table 2, LO; Sul- livan and Maugel, 1984). Protection (sealing the fibrous wall) appears to be a function of the outer structural lamina, LI. In most species, LI is thin (5 ^m or less), usually dense and finely fibered, and reflects the final shape (corrugations and ribbing) imparted by the ventral pedal gland (Gruber, 1982; Sullivan and Maugel, 1984). LI seals the surface of the w hole capsule including the escape aperture, but not the basal plate in contact with the adhesive. Since the contents of some prosobranch egg capsules are axenic but not bacteriostatic (Lord, 1986), the fine structure of this lamina could serve as a ph\sical barrier to invasion by microorganisms, especially in species with a vacuo- lated and fluid-filled L2. (The basal adhesive may also serve as a barrier.) In Urosalpinx cinerea, LI is thick with separated fibers, but the interstices are filled with dense mucus (Tamarin and Carriker, 1967). LI could also serve as a reactive substrate during the molding and hardening process in the ventral pedal gland which fixes the capsule in its final shape (see Gruber, 1982 and Sul- livan and Maugel, 1984). L2 comprises the internal skeleton of the capsule wall in all neogastropod taxa studied except Marginellidae, which has a single structural lamina (tables 1-.3). In some taxa, extensive cross-linkages between the protein fibers form a homogeneous L2. In others, there are dense ho- mogeneous zones on inner and outer surfaces gradually .separating into directionally oriented fibers forming most of the lamina. In ribs or other sculpture, these fibers are loo.sely packed. The homogeneous zones, in addition to skeletal support, could pro\ide another ph\sical barrier to invasion by microorganisms. In Muricacea and Buccinacea, L2 may have fibrous components with different axial orientation often de- scribed as separate layers (Fretter, 1941; Gruber, 1982). Resistance to delamination and cohesiveness suggest that these layers were constructed from the same capsular protein during a continuous process; thus, the\ should be described as parts of a single capsular lamina. If all similar fibrovis components anil contiguous homogeneous C. N. D'Asaro 1988 Page 147 zones from previously described egg capsules of these superfamilies are viewed in this manner (as organized in tables 1, 2), then more meaningful comparisons be- tween taxa can be made. L3 is distinct in most muricaceans and buccinaceans and appears to be a mucoid extension of the apical plug, a part of the hatching mechanism (tables 1, 2). In both species of Cantharus, L3 is not present in most of the capsule wall; however, the mucoid plug in the escape aperture tapers gradually into the wall in a homologous position. There is also mucoid material with chromo- tropic characteristics similar to the apical plug in a ho- mologous basal position suggesting that a thin layer of L3 mucopolysaccharide may be present throughout the wall but could not be identified with the histological technique applied. In the egg capsule of Eupleura cau- data etterae, which was described by Gruber (1982: fig. 14), the singular mucoid plug extending as a layer into the capsule wall and surrounding the lumen can be de- scribed as L3. Lying between the outer structural layers and L3 in E. c. etterae, is another layer (Gruber s sixth layer). The position of this layer, in contact with the equivalent of L2 and surrounding the outer edge of the mucoid plug formed by L3, and its composition suggest that it is homologous with the first mucoid plug in Chi- coreus florifer dilectus (table 1). L4. the albumen retaining layer, is the primary lamina in muricaceans and buccinaceans completely surround- ing albuminous fluids and embryos (tables 1, 2). Often it is not reported in the literature, perhaps because it is 4 nm or less in thickness and usually bound tightly to other components. A function of the layer could be to prevent nonrefractory albumen from mixing with re- fractory capsular proteins when the outer structural lam- inae are assembled by the ciliary mechanism Fretter (1941) described. Albumen in egg capsules of muricaceans and bucci- naceans is stratified to some degree at oviposition (tables 1, 2). This was rather obvious in capsules of Chicoreus florifer dilectus, which had a core of dense albumen, free of embryos, that was structurally different from the surrounding, less dense material. More typically in other species, the core albumen contained the embryos. Dif- ferent layers of albumen in newly deposited capsules suggest that two or more kinds of albumen producing cells exist in the oviducts of the species studied, as Fretter (1941) has demonstrated for several neogastropods. Muricaceans and buccinaceans have structurally sim- ilar barriers closing the escape apertures, which are five to nine times as thick as the capsule wall (tables 1, 2). The increased thickness of the less refractory mucoid plugs possibly serves to prevent premature hatching of a capsule. In muricaceans, no fibers from the more re- fractory parts of L2 extend into the mucoid plugs. During sectioning, mucoid plugs in the escape aperture fractured across the width of the capsule wall, while the more refractors parts of the capsule delaminated lengthwise. Boundary laminae in the wall (LI and L4) appear to hold the mucoid plugs in position. Conid egg capsules are less complex than those of the Muricacea and Buccinacea and contain smaller structural fibers, usually embedded in a mucoid component. The capsule wall has two laminae (LI and L2) and an al- bumen retaining layer (L4). Rather than having ribbon- like fibers in the laminae (see Flower et ai, 1969, for a discussion of fiber ultrastructure), there are very fine, short, and folded or twisted fibers that overlap into a cross-hatched pattern. A singular mucoid plug lying be- tween the outer laminae, LI, and the albumen retaining layer, L4, and interdigitating extensively with the fibrous middle lamina seals the escape aperture. Extensive in- terdigitation would require simultaneous formation of L2 and the mucoid plug. There is no evidence in the conids studied of a lamina equivalent to L3 associated with the mucoid plug. These differences in micromor- phology suggest that important differences in oviducal structure and function exist between conids and muri- caceans and buccinaceans. Pustulate marginellid egg capsules are microstruc- turally the least complex of the taxa studied, and differ markedly from capsules of other neogastropods. Each is constructed of three homogeneous components fused al- most indistinguishably into the others to form a capsule in which the parts do not delaminate during sectioning. Resistance to delamination and a uniform response to toluidine blue suggest that only one protein was used to form the capsule wall. There is no complex escape ap- erture, but in many marginellids it is possible to identify a preformed suture at which the capsule will break dur- ing hatching. The suture is visible at one end and on the sides, which corresponds exactly to the position where the capsule wall breaks during hatching. These features also suggest that the structure and function of the mar- ginellid oviduct is different from that of the major su- perfamilies studied. Although this study does show that there are micro- morphological features common to the egg capsules of some prosobranch taxa, it does not provide clear evidence that can be used to explain exactly how capsules are formed in the oviducal glands. It can be inferred that L4, the albumen retaining layer, is deposited around the albumen and embryos to hold them in a central position \\ hile the more refractory parts of the capsule are formed. It can also be inferred that for most species the remaining parts of the process involve sequential deposition of struc- tural laminae, as Fretter (1941) described for Nassarius reticulatits, with L3 and formation of the innermost mu- coid plug being the second part of the process. The third part of assembly would involve formation of the main structural lamina, L2, and the outer mucoid plug. LI would be the last structural lamina added. Sculpturing, hardening, addition of nonstructural la\ ers, and attach- ment with an adhesi\e are functions of the ventral pedal gland (Sullivan and Maugel, 1984). ACKNOWLEDGEMENTS I wish to acknowledge the revisions to the manuscript suggested by a colleague. Dr. Paul V. Hamilton. Some of the specimens sectioned were provided by Mr. Larry Page 148 THE NAUTILUS, \'ol. 102, No. 4 Dilmore. This project was financed in part with funds from the U.S. Environmental Protection Agency (CR- 811649) and the University of West Florida. LITERATURE CITED Abe, .Naoya. 1983. Breeding of Thais clavigera (Kiister) and predation of its eggs by Cronia margariticola (Broderip). In: Morton, B. and D. Dudgeon (eds.). Proceedings of the Second International Workshop on the Malacofauna of Hong Kong and Southern China Hong Kong University Press, Hong Kong, p. 381-392. Ankel, W. E. 1929. Lber die Bildung der Eikapsel bei Nassa-Arten. V'erhandlungen der Deutschen Zoologischen Gesellschaft, Zoologischer Anzeiger, supplement 4:219- 230. Ankel, W. E. 1937. Der feinere Bau des Kokons der Purpur- schnecke Nucella lapiUus (L.) und seine Bedeutung fiir das Laichleban. Verliaiidlungen der Deutschen Zoolo- gischen Gesellschaft, Zoologischer Anzeiger, supplement 10:77-86. Bandel, K. 1975. Embryonalgehause Karibischen Meso- und Neogastropoden (Mollusca). .\kademie der Wissenschaf- ten und der Literalur. Mainz. Abhandiuiigen der Math- ematisch-Xaturwissenschaftlichen Klasse. 1975(1): 1-133. Bandel, K. 1976a. Morphologic der Gelege und okologische Beobachtungen an Muriciden (Gastropoda) aus der siid- lichen Karibischen See. Verhandlungen der Naturfor- schenden Gesellschaft in Basel 85(1/2): 1-32. Bandel, K 1976b Spawning, development and ecology of some higher Neogastropoda from the Caribbean Sea of C;olombia (South America), X'eliger 19:176-193. Bandel, K. 1976c Morphologic der Gelege und okologie Beo- bachtungen an Buccinacean (Gastropoda) aus der siidlich- en Karibischen See. Bonner Zoologische Beitraege 27:98- 133, Bandel, K. 1982. Morphologic und Bildung der friihontoge- netischen Gehause bei conchiferen Mollusken Facies (Er- langen) 7:1-153. Bayne, C. J. 1968 Histochemical studies on the egg capsules of eight gastropod molluscs. Proceedings of the Malacol- ogical Society of London 38:199-212. D'Asaro, C.N. 1970. Egg capsules of prosobranch mollusks from south Florida and the Bahamas and notes on spawn- ing in the laboratory Bulletin of Marine Science 20:414- 440. D'Asaro, C. N. 1986a. Egg capsules of eleven marine proso- branchs from northwest Florida Bulletin of Marine Sci- ence 39(1):76-91. D'Asaro, C.N. 1986b. Laboratory spawning, egg membranes, and egg capsules of 14 small marine prosobranchs from Florida and Bimini, Bahamas. American Malacological Bulletin 4(2): 18.5- 199. Flower, N. E. 1973. The storage and structure of proteins used in the production of egg capsules by the mollusc CominvUa maculosa. Journal of l'ltra.*tructure Research 44:1.34-145. Flower, N. E., A. J. (;eddes, and K M Kudall 1969 I'ltra- structurc of the fibrous prolcin from the egg capsules of the whelk Buccinium undatum Journal of Ultrastructure Research 26:262-273. Franc, A. 1940, Recherchessur ledeveloppement d'Ocinefcra ackulala Lamarck (Mollus()uc gasteropode). Bulletin Biol- ogicjue de la France ct dc la Belgique 74327-345. Fretter, V. 1941. The genital ducts of some British stenog- lossan prosobranchs. Journal of the Marine Biological As- sociation of the I iiited Kingdom 25173-211 Goldsmith, L. A., H, Hanigan, J M, Thorpe, and K. A. Lind- berg. 1978. Nidamental gland precursor of the egg cap- sule protein of the gastropod mollusc Busycon carica. Comparati\e Biochemistr\ and Physiology 59B:I33-138. Gruber, G. L. 1982. The role of the ventral pedal gland in formation of an egg capsule by the muricid gastropod Euplcura caudata etterae B. B Baker. 1951: an integrated belia\ ioral. morphological, and histochemical study Mas- ter s thesis. University of Delaware, 142 p. Gurr, E. 1962. Staining animal tissue, practical and theoret- ical. Leonard Hill, London. 631 p. Hancock, D. A. 1956. The structure of the capsule and the hatching process in Urosalpinx cinerea (Say). Proceedings of the Zoological Society of London 127565-571. HarasewNch, M. G. 1978. Biochemical studies of the hatching process in Busycon. Master's thesis. University of Dela- ware, Newark, 52 p Hunt, S. 1971. Compari.son of three extracellular structural proteins in the gastropod mollusc Buccinum undatum L., the periostracum, egg capsule, and operculum. Compar- ative Biochemistry and Physiology 40B:37-46. Lord, .\ 1986. .\Te the contents of egg capsules of the marine gastropod Nucella lapillus (L.) axenic':* American Mala- cological Bulletin 4(2):201-204. Moore, E. A. and F Sander 1978 Spawning and early life historv of Murex pomum Gmelin, 1791. N'eliger 20:251- 259. Pechenik, J. .\. 1979. Role of encapsulation in in\ertebrate life histories. American Naturalist 104(6):859-870. Pechenik, J. A. 1983. Egg capsules of Sucella lapillus (L.) protect against low-salinit\ stress. Journal of Experimental Marine Biology and Ecologv 71:165-179. Pechenik, J .A,. 1986. The encapsulation of eggs and embryos by molluscs: an overview .American Malacological Bul- letin 4(2): 165-172. Perry, L. M. and J. S. Schwengel. 1955. Marine shells of the western coast of Florida. Paleontological Research Insti- tution, Ithaca, New York, 318 p. Radwin, G. E. and J. L. Chamberlin. 1973. Patterns of larval development in stenoglossan gastropods. Transactions of the San Diego Society of Natural History 17(9): 107-1 18. Sullivan, C. H. and D. B. Bonar 1984. Biochemical charac- terization of the hatching process of llyanassa ohsoleta. Journal of Experimental Zoology 229(2 ):223-234. Sullivan, C. H. and T. K Maugel 1984. Formation, organi- zation, and composition of the egg capsule of the marine gastropod llyanassa obsoleta. Biological Bulletin 167:378- 389. Tamarin, A. and M H C^arriker. 1967. The egg capsule of the muricid gastropod I'rnsalpinx cinerea an integrated stud) of the wall b\ ordinarv light, polarized light, and electron microscop\ Journal of Ultrastructure Research 21:26-40. Webber, H. H. 1977. Gastropoda, Prosobranchia. /n- Giese. J. S. and J. S. Pearse (eds). Reproduction of marine in- vertebrates. Vol. IV, molluscs: gastropods and cephalopods. Academic Press. New York, 114 p. THE NAUTILUS 102(4):149-153, 1988 Page 149 Two New Species of Metula (Gastropoda: Buccinidae) with a Description of the Radula of the Genus Philippe Bouchet Museum National d'Histoire Naturelle 55, rue Buffoii 75005 Paris, France ABSTRACT Two species of Metula H. and A. Adams, 1853, lack a radula, and it is very small in a third species. The morphology of the teeth is significantly different from that in Pisaiiia, and the two genera are probably not closeK related Metula crosnicri new species, from 400-450 m off SW Madagascar, is a large, broad species, with \ery convex whorls and a deep suture. Metula africana new species, from the deep continental shelf off West Africa, is considered the descendant of the Mediterranean Plio- cene M. milraeformis (Brocchi, 1814). This lineage cannot be taken as evidence for Mediterranean-Indo-Pacific connections in the lower Pliocene as claimed by Grecchi (1978). INTRODUCTION The chequered taxonomical history of the generic name Metula H. and A. Adams, 1853, has recently been sta- bilized by Emerson (1986), who clarified the identity of its type species, Buccinum clathratitm Adams and Reeve, 1850. Additional information was provided by Beu and Maxwell (1987). The familial position of the genus has been the subject of a controversy between Ponder (1968, 1973) and Cer- nohorsky (1971). Ponder (1968) described the anatomy of Ratifitsus Iredaie, 1919, and Iredalula Finlay, 1927; he concluded that their peculiar glandular mid-esoph- agus as well as other features of the anterior alimentary canal justified their inclusion in the family Colubrariidae, which he considered to be anatomically distinct from the Buccinidae. Cernohorsky (1971) regarded the pres- ence of a vestigial radula in Ratifusus and Iredalula to indicate placement in the Buccinidae, since the species of Colubrariidae have no radula at all, and he suggested a placement in the buccinid subfamily Pisaniinae. This view has been accepted by most subsequent authors deal- ing with Metula (Olsson and Bayer, 1972; Kilburn, 1975; Houbrick, 1984; Emerson, 1986), who apparently over- looked Ponder s (1973) refutation of Cernohorsky s point of view. Ponder (1973) confirmed that Ratifusus, Ire- dalula. and Colubraria shared the same anatomical char- acters that separate them from the Buccinidae, and com- mented on the radular differences: "It thus appears that some Colubrariidae have lost the radula and that it is relatively small or vestigial in the remainder. It is possible that the whole Metula-Ratifusus series discussed by Cer- nohorsky (1971) belongs in the Colubrariidae as they all have similar shell features" (Ponder, 1973:328). The family Colubrariidae is treated as a synonym of Buccininae by Ponder and Waren (1988), while Beu and Maxwell (1987) recognize a subfamily Pisaniinae, where they include Metula, Colubraria, and a number of other genera. The purpose of the present paper is to provide a name for the West African species that has been known in the recent literature as Metula clathrata Adams and Reeve, and to describe another new Metula from the upper continental slope in the Mozambique channel. Several additional Indo-Pacific species of Metula, now under study, can be distinguished only on the basis of their protoconch, which has already been emphasized by Al- tena (1949) as a taxonomical character. SYSTEMATICS The radula of a species of Metula is figured here for the first time (figure 1). It is very small for a buccinid (ribbon 25 ;um wide; central tooth 6.5 ^m wide, lateral teeth 12 ^m wide) and very similar to the radulae of Ratifusus and Iredalula figured by Ponder (1968): the central tooth has a narrow arched basal plate with 3 long, slender, and equal cusps; the lateral teeth also have a narrow basal plate and 3 long slender cusps, the outermost one being longest. A radula has been looked for, but not found in Metula amosi Vanatta, 1913, and M. cumingi (Adams, 1853); several specimens were examined in each case by A. Waren (personal communication). I do not consider pres- ence or absence of this very reduced radula to be of generic importance. The radula (figure 2) of Pisania striata (Gmelin, 1791), tvpe species of Pisania, is 150 ^m wide; it differs in having a central tooth with a large square basal plate and 5 short and broad cusps, the outermost 2 being small- er; the lateral teeth are more strongly built, with 3 un- equal cusps. In view of the small variation of radular types in buc- Page 150 THE NAUTILUS, Vol. 102, No. 4 cinids, this difference is remarkable and probabK indi- cates that the two genera are not closeK- related. What- ever rank (subfamily or tribe) the Pisania group is given in Huccinidae, additional research is needed before the Colubraria group is considered a mere s>nonym of it. DESCRIPTIONS [For a diagnosis of the genus see Altena (1949) as An- temetula] Metula crosnieri new species (figures 3-5, 9) Description: Shell solid, fusiform, consisting of 2.5 pro- toconch and 6.2 teleoconch whorls. Spire high, body whorl comprising 64% of total shell height. Protoconch (figure 9) with large nucleus of two smooth convex whorls abruptK demarcated from teleoconch. Teleoconch whorls convex, without sutural ramp, with deeply impressed suture. Sculpture of raised spiral cords and curved op- isthocline axial ribs; cords and ribs producing beaded intersections and pitted intervals. Eight spiral cords on spire whorls; 4 minor, intermediate cords on penultimate whorl; about 18 cords above periphery of body whorl, principal and secondary cords alternating rather regu- larly, and 33 cords below periphery, of which about 15 are set close together in siphonal region. Axial ribs about equal in strength to spiral cords on spire whorls; weaker on penultimate whorl, with main sculpture being spiral on body whorl. In addition to axial ribs, several incre- mental scars are obvious, especially on body and pen- ultimate whorls. Aperture ovate; inner lip thin, smooth, adherent to body whorl, thicker in columellar region; outer lip bearing 12 very weak teeth that do not corre- spond with position of external spiral cords; two most apical teeth slightly stronger. Peristome thickened, form- ing broad varix, also covered by spiral cords. Siphonal canal long, broad, widely open, and recurved. Fasciole indistinct. Colour light tan, with a very indistinct darker spiral band at periphery of body whorl; incremental scars light- er; aperture white. Dimensions of the holotype: Height 51 3 mm, width 19.4 mm; height of the aperture 24.5 mm, width 8 mm; height of the body whorl 33 mm. The largest paratype is 55.4 mm high. Type lf>cality: Mozambique channel, SW Madagascar, off Baie de Faiiemotra, 22°15'S, 43°05'E, 470-475 m. Type material: Holotype and paratype 1 (MNHN) from the type locality, collected by A. Crosnier, Dec. 2, 1973 aboard R.V. "N'auban"; paratype 2 (MNHN), Mozam- bique channel, SW Madagascar, 22°17'S, 43°04'E, 400- 450 m, collected by R. v. Cosel, Nov. 30, 1986 aboard trawler "Mascareignes III". Distribution: Known only from llic type material, off SW Madagascar. Figures 1, 2. Scanning electron niicrographi ol raciulac I. Metula africana new species, scale bar lO/iiii. 2. Fisania striata ((Jnielin. 1791), scale bar .50 nm. Remarks: Metula crosnieri has remarkably convex whorls and a deep suture when compared with its con- geners. The protoconch (figure 9) indicates non-planc- totrophic larval development. The combination of these two characters distinguishes it from all known Indo-Pa- cific Metula. In the Atlantic, Bartschia significans Rehder, 1943, type species of Bartschia Rehder, 1943, has even more convex whorls, and a multispiral protoconch. I cannot find characters other than the convexit\- of the whorls that sharply distinguish Bartschia from Metula, and con- clude that Bartschia should be considered at most a sub- genus of Metula. p. Bouchet 1988 Page 151 I am naming this species after my colleague Alain Crosnier, who first collected it during a survey of deep water shrimp populations oft Madagascar. Metula ajricana new species (figures 1, 6-8, 10) Metula clathrata Knudsen, 1956;39, plate 1, figure 1; non M. clathrata (Adams and Reeve, 1850). iKin Metula knudseni Kilburn, 1975:592 (replacement name for Buccinum clathratum Adams and Reeve, 1850: see Emerson, 1986). Description: Shell solid, fusiform, consisting of 7 teleo- conch whorls. (Protoconch of holotype partly broken, on a paratype consisting of large nucleus and 1.5 smooth convex whorls, figure 10.) Teleoconch whorls convex, with faint but distinct sutural ramp on early whorls; ramp indistinct on penultimate whorl, body whorl evenly con- vex. Teleoconch sculpture of raised spiral cords and slightly curved opisthocline axial ribs; intersections dis- tinctly beaded in sutural ramp area, only slightly nod- ulous below ramp. Spiral and axial sculpture of similar strength on early whorls; later spiral sculpture gradually dominates. Nine primary spiral cords per whorl on spire whorls, first (adapical) and third cords stronger, limiting sutural ramp. Fine spiral threads present between cords on penultimate and bod\ whorl, several eventually de- veloping into secondary spiral cords, with one present in sutural ramp area of body whorl. About 22 primary cords below periphery of body whorl, plus another 10 in si- phonal area. Incremental scars distinct; growth lines very distinct between axial ribs. Aperture ovate, narrow. Inner lip thin, smooth, adherent to body whorl, thicker in col- umellar region. Outer lip regularly convex, bearing small teeth that correspond at least partly with position of spiral cords on peristome; a group of 5 teeth forms a small callus in apical portion of outer lip, delimiting small anal canal. Peristome forming a thickened varix, over which spiral sculpture extends. Siphonal canal short, narrow, open, only slightly recurved. Ground colour of shell beige cream, with 3 brown spiral bands; 3 adapical cords brown, interval between them beige cream. Below, uniformly beige band extends over next 2 spiral cords, occupies central position on spire whorls. Darkest band occupies next 4 spiral cords and intervals between them; this band occupying suprasu- tural position on spire whorls, and a central position on body whorl. Below brown band a second beige band extends over 4 spiral cords; next 2 cords brown, with brown colour fading towards base of shell. Aperture cream colored. Dimensions of the shell: Height 54.5 mm, width 17.5 mm; height of the aperture 27 mm, width 7 mm; height of the body whorl 35 mm. Type locality: Off Saint Louis, Senegal, in 300-600 m. Type material: Holotype (MNHN), paratype 1 (MNHN) and paratype 2 (AMNH 198755), all from the type lo- cality, collected by M. Pin on the trawler "Louis Sauger". Figures 3-8. Back, side, and front views. 3-5. Metula cros- nieri new species, holotype, 51.3 mm. 6-8. Metula ajricana new species, holotype, 54.5 mm. Other material examined: SENEGAL: off Saint Louis, "deep water", 4 shells (MNHN, leg. M. Pin), 10 shells (coll. M. Pin, Dakar); IVORY COAST: off Abidjan, 1 shell, coll. Marche-Marchad (MNHN), and 1 shell, P. Le Loeuff coll. (MNHN); EQUATORIAL GUINEA: Atlan- tide Sta. 120, 02°09'N, 09°27'E, 250-850 m, 1 specimen Page 152 THE NAUTILUS, Vol. 102, No. 4 Figures 9. 10. Protoconchs. 9. Metula crosnieri. 10. Metula ajricana. Scale line 1 mm. (Kiiudsen, 1956) (ZMC); CONGO: West of Pointe-Noire, 100 m, 1 shell, A. Crosnier coil. 1962 (ANSP 333810). Distribution: Deep continental shelf and upper slope of West Africa, from Senegal to Congo. Remarks: Metula africana has been figured three times in the literature: by Knudsen (1956: plate 1, figure 1) under the name Metula clathrata; by Emerson (1986: figures 4, 5) as Metula sp.; finally by Kaicher (1987: card 4851) as Metula sp. I refer to Emerson (1986) who re- viewed the nomenclature of this West African Metula and concluded that it represents a new species. The protoconch (figure 9) indicates non-planctotro- phic larval development. There may be clinal variation in adult size along the West African coast: The 18 shells examined from Senegal have a mean height of 41.7 mm; the 2 shells from Ivory Coast, although fully adult, measure 32 and 36 mm; that from Equatorial Guinea is 30.6 mm high, and that from Congo 25.5 mm. The tiny rachiglossate radula (figure 1) was prepared from the specimen taken during the .-Ktlantide expedition (ZMC). The close connection between Mediterranean Pliocene and Recent West African marine faunas has been dem- onstrated in a number of paleontological papers (for re- cent reviews see Ruggieri, 1967; Marasti and Raffi, 1979; Sahelli and Taviani, 1984). With a single species of Me- tula present in the Pliocene of Italy and a single Recent species in West Africa, it is reasonable to assume that Metula mitraeformis (Brocchi, 1814) (for figures and references see Pelosio, 1966) is the direct ancestor to M. africana. I have examined material of the fossil species and found it to differ from the Recent one by its much weaker axial sculpture, which on the body and penul- timate whorls is limited to growth lines. In M mitrae- formis, there is a very broad sutural ramp that extends over the adapical third or half of early teleoconch whorls, and becomes obsolete on the penultimate and body whorls; the siphonal canal is also broader. Because he was mistaken about the identity, type lo- calit\, and distribution of M. clathrata, Grecchi (1978) speculated that the presence of its presumed ancestor M. mitraeformis in the Mediterranean Pliocene was an in- dication of Mediterranean-Indo-Pacihc connections in the lower Pliocene after the Messinian salinity crisis. With M. clathrata now known to be a West American species distinct from M. africana, the history of the M. mitraeformis-africana lineage can not be taken as an indication of such connections. This lineage probably has an Eastern .Atlantic history dating to the Miocene; al- though the Neogene West African fossil record is lacking, it is far more probable that M. mitraeformis reinvaded the Pliocene Mediterranean from West Africa rather than from the Indo-Pacifie through unproven maritime con- nections. ACKNOWLEDGEMENTS I thank Dr. A. Waren who prepared the radula of Metula africana and commented on the manuscript. A. Crosnier, M. Pin, and R. von Cosel collected most of the material cited in this paper. Dr. W. Emerson generousK refrained from describing M. africana when he learned 1 was working on it. Photography is b\ P. Lozouet. LITERATURE CITED Alteiia, C O van R 1949. The genus Antemetula Rehder in the Indo-West Pacific area, with the description of two new fossil species. Bijdragen tot de Dierkdunde 28:385- 393. Beu, A. G. and P. A. Maxwell. 1987. A revision of the fossil and living gastropods related to Plesiotriton Fischer, 1884 (Family Cancellariidae, Subfamily Plesiotritoninae n. subfam.) with an appendix: genera of Buccinidae Pisani- inae related to Colubraria Schumacher. 1817. New Zea- land Geological Survey Paleontological Bulletin 54:1-140, Cernohorsky, W. 1971. Indo-Pacific Pisaniinac and related buccinid genera. Records of the .\uckland Institute and Museum 8:137-167. Emerson, W. K. 1986. On the type species of Metula H. & \. Adams, 1853: Buccinum clathratum A. .\dams and Reeve, 1850. The Nautilus 100(1 ):27-:30 Grecchi, G. 1978. Problems connected with the recorded occurrence of some mollusks of Indo-Pacific affinit\ in the Pliocene of the Mediterranean area Rivisla Italiana di Paleonlologia 84:797-812. Houbrick, R. 1984. A new "Metula" species from the Indo- West Pacific. Proceedings of the Biological Society of Washington 97(2):420-424. Kaicher, S. D. 1987. Card catalogue of world-wide shells. Pack 48: Buccinidae, part 3 Published by the author, St. Petersburg. Killnirn, R N 1975. Taxonomic notes on South African ma- rine Mollusca (5): including descriptions of new ta\a of Rissoidae, Cerithiidae, Tonnidae, Cla.ssididae, Buccinidae, p-asciolariidae, Turbinellidae, Turridae, Architectonici- dae, Epitoniidae, Limidae, Thraciidae. Annals of the Natal Museum 22(2):577-622. Knudsen, J. 1956. Marine prosobranchs of tropical West Af- rica (Stenoglossa). Atlantide Report 4:7-110. Marasti, R and S. Raffi 1979 Observations on the paleocli- matic and biogeographic meaning of the Mediterranean p. Bouchet 1988 Page 153 Pliocene molluscs. State of the problem. 7th Intenuilinnal Congress on Mediterranean Neogene, Athens, 8 unnum- bered pages. Olsson, A. and F. Bayer. 1972. American Metulas (Gastro- poda: Buccinidae). Bulletin of Marine Science 22(4):900- 925. Pelosio, G. 1966. La Malacofauna dello stratotipo del Tabi- aniano (Pliocene inferiore) di Tabiano Bagni (Parma). Bol- lettino della Societa Paleontologica Italiana 5(2):l()l-183. Ponder, W. 1968. Anatomical notes on two species of the Colubrariidae. Transactions of the Roval Society of New- Zealand, Zoology 10(24):217-223. Ponder, W. 1973. The origin and evolution ot the Neogas- tropoda. Malacologia 12(2):295-338. Ponder, W. and A Waren 1988 Classification of the Cae- nogastropoda and I leteroslropha — a li.sl of the family-group names and higher taxa. Malacological Review, supplement 4:286-32-1. Ruggieri, G. 1967. The Miocene and later evolution of the Mediterranean Sea. In: Adams, C. G. and D. V. Ager (eds.). Aspects of Tethyan biogeography. The Systematics Asso- ciation, London. P. 283-290. Sabelli, B. and M. Taviani. 1984. The paleobiogeographic distribution of the Mediterranean benthic mollusks and the Messinian salinity crisis or where did the mollusks go? Annales de Geologic des Pays Helleniques 32:263-269. THE NAUTILUS 102(4):154-158, 1988 Page 154 A New Species of Intertidal Terebra from Brazil Kurl Auffenberg Malacolog> Division Florida Museum of Natural History University of Florida Gainesville, FL 32611. USA Harry G. Lee 709 Uomax Street Jacksonville, FL 32204, USA ABSTRACT Terebra imitatrix new species is described from northern Brazil and compared to morphologically similar species of Hastnla. The three known terebrid feeding types are briefl\ reviewed. Dissection of the foregut of this new species revealed characters that overlap two of the major feeding types. Key words: Gastropoda; Terebridae; Terebra; anatom\ : Bra- INTRODUCTION While compiling distributional records of the West At- lantic Hastula cinerea species group, the junior author located an unidentified lot of 23 specimens from Brazil in the Academy of Natural Sciences of Philadelphia (ANSP 299957). These specimens were compared to the known terebrids from the Atlantic and were found to belong to a distinct undescribed species. An additional lot of the same species was subsequently found in the American Museum of Natural History (AMNH 129280). Matthews et al. (1975:99, fig. 31) in their treatment of Hastula ciiterea describe and illustrate a protoconch con- sistent with this new species. The Brazilian specimens of Hastula salleana (Deshayes, 1859) figured by Rios (1970: 123, pi. 47, 1975:127, pi. 38, fig. 560, 1985:131, pi. 45) are probably referable to this new species, but the figured specimen was unavailable for examination. This paper describes this new species and compares it with mor- phologically similar species of Hastula. A description of the foregut anatomy reveals that it does not conform to any of the three known feeding types, which are re- viewed herein. MATERIALS AND METHODS Only shells possessing 10 or more teleoconch whorls and with intact protoconchs and apertures were measured with Vernier calipers. All dissections were made under a Wild M-5 dissecting micro.scope and line drawings made with the aid of a camera lucida. Description and discussion of the anatomy is limited to the foregut due to poor preservation in the upper whorls. Anatomical and protoconch measurements were made with an ocular micrometer and converted to millimeters. Terminology follows that of Miller (1970, 1971). Two preserved but completeK retracted adult specimens of the new species (ANSP 299957), Hastula maryleeae Burch (UF 113539) and Hastula salleana (Deshayes) (UF 48197, 113540), were dissected from each lot. Two dried-in specimens of Hastula maryleeae Burch (T. Bratcher collection) were rehydrated in a weak solution of potassium h\dro.\ide, transferred into water, and dissected. The radular sac was extracted and dissolved in a weak solution of potas- sium hydroxide. Radular teeth were individual!} mount- ed on scanning electron microscope specimen stubs cov- ered with double-sided tape. Micrographs were made with a Hitachi 5-415.^ scanning electron microscope. Repositories of examined specimens are indicated by the following abbreviations: AMNH American Museum of Natural Histor\' ANSP Academy of Natural Sciences of Philadelphia UF Florida Museum of Natural History SYSTEMATICS Family Terebridae Morch, 1852 Genus Terebra Bruguiere, 1789 Terebra imitatrix new species (figures 1-6, 8, 9, table 1) Description: Shell (figures 1-3, 6) medium in size, broadening anteriorK ; color variable, ranging from banded, or cream, to purplish-brown; teleoconch whorls 10-12; sides flat to slightly convex. Protoconch whorls 1.5-2.0; glassy, transparent (figure 6). .\xial sculpture of close-set, recurved ribs of \ariable strength, generally distinct near the suture, becoming obsolete anteriorly; major axial ribs 34-57 (x = 41.6) on the penultimate whorl. Spiral sculpture of very faint microscopic incised lines most distinct in the intercostal spaces on the upper whorls, obsolete on later whorls, rarely cro.ssing the axial ribs; spiral rows of pits absent. Last whorl with obsolete axial ribs and spiral incised lines; color pattern variable, typicalK of five diffuse color bands: one white pre-sutural band usiialK w ith distinct brown spots that become ob- solete toward apertural lip, one broad bluish-black zone at shoulder, one pinkish band at periphery, one purplish- K. Auffeiiberg and H. G. Lee 1988 Page 155 4 Figures 1-3. Terebra imilatrix new species. 1. Holotype, ANSP 299957 (27.5 mm shell length) 2, 3. Paratypes, ANSP 369293, all from Rio Grande do Norte, Brazil, -sand island at mouth of the inlet at Areia Branca. brown band below periphery, and one white basal zone. Columella brown, centrally concave and slightly re- curved; rounded rib present on anterior edge. Parietal callus thin, transparent to light brown. Fasciole white to bluish-gray with distinct white rib. Anterior siphonal notch moderately broad, straight. Aperture light to dark brown with white band. External anatomy: Animal cream-colored with no ap- parent pattern in alcohol-preserved specimens. Oper- culum corneous, small, thin. Eyes on short, broad eye- stalks. Labial tube large, spoon-shaped (figure 4). Anterior end of labial tube terminating in thick muscular lips bounding mouth slit; well-developed sphincter lacking. Foregut anatomy: Labial cavity large, dominated by massive (3.7 mm), extendable, muscular organ (accessory feeding apparatus; Miller, 1970, 1971) that tapers an- teriorly; muscular organ with two rows of papillae on ventral side (figure 4); attached posteriorly to the left side of the cephalic hemocoel by connective tissue; re- tractor muscle large, originating in foot below and slight- ly posterior to anterior siphon, passing through cephalic hemocoel. Buccal tube muscular, short (0.9 mm), taper- ing anteriorly. Buccal cavity small (0.6 mm), rounded. Pre-ganglionic esophagus enters buccal mass posteriorly (figure 4). Salivary glands not located. Radular sac blade- shaped, small (0.8 mm). Radular caecum (0.4 mm) with well-developed groove running posteriorly, two distinct bulbs anteriorly (figure 5). Radular organs attached to right side of anterior portion of buccal cavity by very short duct (0.1 mm). Two rows of radular teeth situated obliquely in radular sac and caecum (figure 5). Radular teeth about 30; 0.1-0.2 mm in length, slightly curved, not barbed (figures 8, 9). Poison gland long (6.2 mm), extremely convoluted, entering right side of buccal cav- ity slightly behind radular sac (figure 5). Poison bulb small (0.9 mm), weak, seemingly vestigial, lying at ven- tro-posterior end of cephalic hemocoel. Etymology: From the Latin feminine noun meaning one who imitates, in reference to the deceptively close resemblance of the shell to that of Hastula cinerea (Born, 1778), with which it occurred in the type lot. Table I. Measurements (mm) of shell characters of Terebra imitatrix new species and Hasttila rnaryleeae Burch Species Character X Range SD T. imitatrix Shell length 27.3 24.1-29.7 1.9 Shell width 6.4 5.7-7.4 0.5 Protoconch 0.50 0.46-0.52 0.03 width H. rnaryleeae Shell length 18.2 15.0-24.1 2.7 Shell width 4.6 3.7-5.5 0.6 Protoconch 0 40 0.38-0.42 0 02 width Page 156 THE NAUTILUS, Vol. 102, No. 4 •■s be Figures 4-6. Terebra irnitatrix new species. 4. Diagrammatic dorsal view nf the organs of the foregut 5. Right side of the buccal tulie showing radular organs and insertion of the poison gland. 6. Protoconch. 7. Hastula manjleeae Burch, protoconch (.-WINH 191815) Scale bars = 1 mm. af, accessory feeding apparatus; be, buccal cavity; bt, buccal tube; It, labial tube; pb, poison bulb; pe, pre-ganglionic esophagus; pg, poison gland; re, radular caecum; rm, retractor muscle; rs, radular sac. Type locality: Brazil, Rio Grande do Norte, sand island at mouth of the inlet at Areia Branca, 04°57'S, 37°08"W, G. & M. Kline et al., 14 December 1963. Holotype: ANSP 299957, shell length 27.5 mm, width 6.7 mm. Paratypes: Paratypes 1-20, ANSP 369293, from the tvpc locality (15 dry, 5 in alcohol). Paratypes 21-22, UF 115180, from type locality. Paratypes 23-24, AMNH 129280, Brazil, Ceara, Acaraii, 02°53'S, 40°07'W. Distribution: PresentK know n onl\- from northern Bra- zil. Ecology: Based on the locality label of the type lot, this species is found in sand near or at inlets much like some populations of Hastula. One specimen of Hastula ci- nerea (Born, 1778) was found in the type lot and another (AMNH 129269) from the same locality as the AMNH- paratypes. Although these two species may occur micro- s\ mpatrically, we assume there is no trophic competition due to the strikingly divergent feeding organs (see dis- cussion). Comparative remarks: Terelrra irnitatrix is similar in shell morpholog\- to the West Atlantic Hastula cincrea group. It can be easily separated from Hastula cinerea and Hastula salleana by the lack of spiral rows of pits and the generally more numerous, but less prominent, axial ribs. .Although similar in size, T. irnitatrix is usually broader anteriorly . Hastula cinerea and H. salleana have 3.5-4.0 protoconch whorls, while T. irnitatrix has 1.5- 2.0. The typical color pattern of T. irnitatrix is more distinctK banded with larger and more distinct brown spots al the suture and a broader white subsutural band. Terelna irnitatrix and Hastula manjleeae are more dif- ficult to separate, particularly southern Caribbean pop- K. Auffenberg and H. G. Lee 1988 Page 157 Illations of H. niarijleeae described as Terehra toba- goensis Nowell-l'slicke, 1969, now placed in the s\non\ my of H. manjleeae by Bratcher and Cernohorsky (1987). Examination of the lectotype (AMNH 195453 designated bv Bratcher and Cernohorsky, 1987:194, pi. 60, fig. 235c)' and paralectotypes (AMNH 191819) of T. tobagoensis. as well as several other lots from Tobago, typical specimens of H. manjleeae from Te.xas, and spec- imens of a weakly ribbed form of H. maryleeae from the Dominican Republic (see Bratcher and Cernohorsky, 1987, for discussion) revealed consistent shell characters b\ which the two species may be separated. Anatomical features are discussed below. Typical H. maryleeae is easily separated from T. imitatrix by the distinctive shell shape caused by the enlarged nodes of the axial ribs at the suture and by the slight crenulations at the sutures of the upper whorls. Hastula manjleeae has a much smaller shell than T. imitatrix at the same whorl count (table 1). The shell of T. imitatrix broadens more an- teriorK- and has a proportionately slightly larger aper- ture. The protoconchs of both species have 1.5-2.0 whorls, however, the protoconch of T. imitatrix is more bulbous (figures 6, 7; table 1). Typical T. imitatrix also resembles the West African Hastula aciculina (Lamarck, 1822), particularK- in color pattern. However, T. imitatrix lacks the supra-sutural groove and callosity found in H. acic- ulina (Bouchet, 1982; Bratcher and Cernohorsky, 1987). DISCUSSION Miller (1970) proposed a division of the Terebridae into three major groups based on the anatomy of the foregut (feeding type) and later published a series of papers (Miller, 1971, 1975, 1979) on this subject supported by in-depth life history studies. These data are reviewed and the species assigned to each group are listed in Bratcher and Cernohorsky (1987). Type I species have a long labial tube and a short buccal tube. They do not possess a radular apparatus or poison organs. This group is further divided into two subgroups, lA and IB, based primarily on habitat and pre%' (see Bratcher and Cer- nohorsky, 1987). Type II encompasses species exhibiting typical toxoglossan feeding characters. The labial tube is long and eversible and the buccal cavit\ is relatively large. The buccal tube is long and retractile. They have a poison gland and bulb as well as a radular sac containing two rows of harpoon-like radular teeth. This feeding type is further divided into two subgroups, types IIA and IIB, based primarily on habitat and behavior. Type IIA in- cludes several Indo-Pacific species, as well as the West Atlantic Hastula discussed in this paper (see Bratcher and Cernohorsky, 1987). Type III species possess an ac- cessory feeding organ which grasps prey and pulls it into the labial cavity. The\' lack a radular apparatus and some have lost the buccal tube and salivary glands. This group presentK contains no .\tlantic species, but is represented b\' several Indo-Pacific taxa (see Bratcher and Cerno- horsky, 1987). Terebra imitatrix has very different foregut anatomy Figures 8, 9. Radular teeth of paratype (ANSP 369293) of Terehra imitatrix. new species. 8. Whole tooth, 60 x . 9. Tip of lootli, 200 X. from the West Atlantic Hastula. We have dissected H. salleana and H. manjleeae for comparison, and both possess a Type IIA polyembolic proboscis (Miller, 1970, 1971). Terebra imitatrix has a large spoon-shaped labial tube, presumably ineversible, a labial cavity dominated by the accessory feeding apparatus, an extremely short buccal tube incapable of extending outside the mouth and the buccal cavity, and the associated radular organs are minute in comparison to those of Hastula. The ves- tigial poison gland and bulb are barely recognizable as such and are considered homologous to the massive poi- son gland and bulb of Hastula only by the similarity of position and the site of its entrance into the buccal cavity. The radular teeth are similar in size and shape to those of Hastula maryleeae (0.15 mm). The teeth of H. sal- leana and H. cinerea are larger (0.5 mm) and barbed. The presence of an accessory feeding apparatus and the small size of other foregut organs place T. imitatrix near the group possessing a Type III polyembolic proboscis. However, the presence of radular and poison organs, such as occur in T. imitatrix, has not been reported for this proboscis type. Also, the shell of T. imitatrix is very different from the species in this group, all of which have shells with deeply impressed sutures, a sub-sutural groove and strong to moderate axial sculpture. The feeding behavior of Hastula cinerea and of H. inconstans (Hinds, 1844) have been well documented by Marcus and Marcus (1960) and Miller (1979), re- spectively. The long eversible labial tube forages for prey items. A single radular tooth is passed through the labial tube, held in the tip, and inserted into the prey to fa- cilitate penetration of the venom. The prey is then in- gested via the labial tube. Miller (1970) suggests that species with a Type III proboscis forage by utilizing the accessory feeding apparatus, and that food items are passed into the opening of the interior buccal tube. We do not know if the radular and poison organs are func- tional in Terebra imitatrix. If so, the radular tooth is either transferred from the buccal tube to the accessory feeding apparatus and inserted into prey outside the body, or once it reaches the buccal tube. Page 158 THE NAUTILUS, Vol. 102, No. 4 The presence in Terebra imitatrix of the accessory feeding apparatus recorded in a few Indo-Pacific Tere- bra and the poison anil radiilar organs of Hastula make this species unique. Terelna imitatrix may be closely related to the West African species, Hastula aciculina, however, this species must be studied anatomically be- fore this assignment can be verified Generic limits within the Terebridae are presently p<}ori\ understood with much overlap in shell and anatomical characters. Additional anatomical studies are needed to clarify the taxonomic and e\oiutionar\ significance of the foregut in the Tere- bridae. ACKNOWLEDGEMENTS We wish to thank several people who have assisted us during this study. Special thanks go to Robert Robertson, George M. Davis, and Mar) \. (iarback of the .\cademy of Natural Sciences of Philadelphia for allowing us to borrow and dissect the specimens on w hich this descrip- tion is based. William K. Emerson, Harold Feinberg, and Walter Sage at the .American Museum of Natural Histor\ allowed us to visit their department and borrow several lots of \ery pertinent material. Twila Bratcher of Hol- lywood, California kindly provided comparative mate- rial, as did Eliezar C. Rios (Funda^ao Universidade do Rio Grande do Sul, Brazil), the late Joseph Rosewater of the U.S. National Museum, and Thomas Pulley and Con- stance Boone of the Houston Museum of Natural Science. Marcos Guianaldo and Armando Garcia, Florida Mu- seum of Natural History, prepared figures 4-7. The mi- crographs were made by the senior author with the scan- ning electron microscope housed in the Department of Zoology, University of Florida. In addition, we thank Richard S. Houbrick, William K. Emerson, and Fred G. Thompson for reviewing earlier drafts of the manuscript. LITERATURE CITED Bouchet. P. 1982. Les Terebridae (Mollusca, Gastropoda) de r.\tlantique Oriental. Bollentino Malacologico, Milano 18(9-12):18.5-2I6. Bratcher, T. and \V. O. Cernohorsky 1987 Living terebras of the world .\ monograph of the Recent Terebridae of the world .Xmerican Malacologists, Inc.. Melbourne, FL, 240 p. Marcus, E. and E. Marcus 1960. On Hastula cinerea. Bo- leiitim Faculdade de Filosofia Ciencias e Letras. Univer- sidade de Sao Paulo, no. 260, Zool. no. 23:25-54, pis. 1-5. Matthews. H. R., \. C. Dos Santos Coelho, P. De Sa Cardoso, and M. Kempf. 1975. Notas sobre la familia Terebridae no Brasil (Mollusca, Gastropoda). .-Vrquivos do Museu Na- cional. Rio de Janiero 5585-104. Miller. B .A 1970 Studies on the biologN of Indo-Pacific Terebridae. Ph D. dissertation. I'niversity of New Hamp- sliirc. Durham. 213 p. Miller, B. .\. 1971. Feeding mechanisms in the family Tere- bridae. .Annual Report of the American Malacological I'nion for 1970. 1970:72-74. Miller. B. .A. 1975. The biolog\ of Tereiwa gouWi Deshayes, 1859, and a discussion of the life history similarities among other terebrids of similar proboscis tvpe Pacific Science 29:227-241. Miller, B. .\. 1979. The biology of Hastula inconstans (Hinds, 1844) and a discussion of life histor\ similarities among other Hastula of similar proboscis type. Pacific Science 33(3):289-306. Nowell-l'sticke, G. W. 1969 .A supplementary listing of new shells (illustrated). Privately published. St. Croix, Virgin Islands, 31 p., 4 pis. Rios, E. C. 1970, Coastal Brazilian shells Funda(,ao Cidade do Rio Grande, Museu Oceanografico de Rio Grande, Bra- zil, 255 p.. 60 pis. Rios, E. C. 1975. Brazilian marine mollusks iconograph\. Fundagao Universidade do Rio Grande, Centro de Cien- cias do Mar, Museu Oceanografico, Brazil, 331 p., 91 pis. Rios, E. C. 1985. Seashells of Brazil Funda^ao Cidade do Rio Grande, Fundagao Universidade do Rio Grande, Mu- seu Oceanographico, Brazil, 329 p , 1421 pis. THE NAUTILUS 102(4):159-163, 1988 Page 159 Notes on the Biology and Morphology of Margaritifera hembeli (Conrad, 1838) (Unionacea: Margaritiferidae) Douglas G. Smith Museum of Zoology Universit\ of Massachusetts Amherst, MA 01003-0027, USA ABSTRACT The freshwater pearl mussel Margaritifera hembeli is found onK in the Red River basin and a few nearby drainages in Louisiana. Though of concern to conservationists because of its declining numbers, M. hembeli remains virtually unknown with respect to its anatomy and biology. The species contains all the anatomical characters that typify margaritiferid species. The sexes are separate and the gonads show a definite seasonality in activity. Gametogenesis is pronounced in specimens collected in the fall, followed by degeneration of reproductive tissues in the late winter through to late spring. It is concluded, on the basis of observed gonadal activity, that oviposition and spawn- ing take place between late November and late January Char- acters are evident in the morphology of the visceral nervous svstem and the stomach of M. hembeli that clearly distinguish M. hembeli from M. marrianae and other eastern North Amer- ican margaritiferid species. A distinct relationship between M. hembeli and M. marrianae, however, is suggested by the mu- tual occurrence of lateral hinge teeth and a corrugated surface of the posterior portion of the shell. Due to the lack of knowl- edge of the anatomy and biology of other margaritiferid species, especially those living in Asia, it is premature to suggest rela- tionships lietween M. hembeli and other described margari- tiferid species, particularly those with lateral hinge teeth. Key uords: Margaritifera: anatomv, reproduction. North .America INTRODUCTION The North American freshwater mussel Margaritifera hembeli (Conrad, 1838) was once believed to comprise two geographically discontinuous populations ta.xonom- ically linked b\ vague similarities of the shell. Johnson (1983) separated the two populations taxonomically by describing the Alabama group as M. marrianae, thus restricting the M. hembeli group to Louisiana. His de- scription included characters of the shell only, principally the degree of sculpturing on the shell surface and the shape of the ventral shell margin. Additional concho- logical differences between the Louisiana and Alabama populations were noted by Smith (1983) who pointed out dissimilarities in the mantle-shell attachment scars on the inner nacreous surface. Margaritifera hembeli probably had a more extensive range in the Red River drainage as indicated by museum records, particularly a specimen in the American Mu- seum of Natural History (AMNH 193786) from the Red River in Arkansas. During the present century, however, the range has contracted considerably due to deterio- rating environmental conditions. The present range is limited to the Bayou Teche drainage (Vidrine, 1985) and a single stream in the Red River drainage. The drastic reduction in range has elicited concern from the federal government, which has provided protection for the re- maining populations (Stewart, 1988). Despite increased concern for M. hembeli, very little is known about this species other than the characteristics of its shell. Ortmann (1912) provided a brief description of the anatomy of M. "hembeli, ' but the specimens upon which he based his description came from Alabama and, therefore, are appropriately referred to M. marrianae. Hence the anatomy of M. hembeli remains undescribed, and nothing is known about its biology. The present study provides some information on gonadal activity and de- tails of the anatomy of the stomach and nervous system. Comparisons are made with other North American mar- garitiferid species, including M. marrianae, as studied by Smith (1979a, 1980, 1986, and unpublished). MATERIALS AND METHODS A total of 43 partially or completely relaxed, preserved, specimens were studied. All were collected on various dates from 1973 to 1986 from Brown Creek, Gardner, Rapides Parish, Louisiana. Specimens had been fixed in 10% formalin, washed in water, and stored in 50% iso- propyl alcohol. Five specimens lacked information on date of collection and were utilized for dissection pur- poses only. The remaining lots were used for histological investigations of gonadal activity and sexual character- istics, as well as for anatomical studies. The collection dates and numbers of specimens used in the study of gonadal activity were as follows: October 1, 1973 (1 specimen); October 5, 1974 (4 specimens); February 22, 1975 (8 specimens); March 28, 1975 (4 specimens); April 25, 1975 (3 specimens); June 21, 1975 (2 specimens); March 30, 1986 (5 of 16 specimens). Page 160 THE NAUTILUS, Vol. 102, No. 4 Figure 1. Photomicrograph of a transverse section through the gill of Margaritifera hcmheli showing the interlamellar junction (ILJ), 30 x Portions of the viscera of each specimen were infil- trated with paraffin, sectioned at seven micrometer thick- ness, and stained with Ehrlich's hematoxylin and eosin. Some sections were stained in a picro- ponceau connective tissue stain following the method described in Humason (1979:147). At least five slides were prepared for each specimen. The barren gills of two specimens and a por- tion of the posterior mantle lobe of one specimen were also sectioned in a similar manner and stained with picro- ponceau connective tissue stain. Dissections were undertaken on the stomach and vis- ceral nervous system of eight specimens. Three speci- mens were investigated for gro.ss morphology of the gills, nervous system, and excretory system. The method of dissection and exposition of specific internal organs, and the terminologv used to describe various organ compo- nents, follows Smith (1980, 1986). .\11 material relevant to this study has been cataloged in the invertebrate collections of the Museum of Zoology (Nos. MO. 1643-1645), University of Massachusetts, Am- herst, Massachusetts. RESULTS Gross Anatomy Anterior and posterior adductor muscles subequal, foot musculature and associated pedal and retractor muscles well developed Cerebral and pleural ganglia fused, kid- ney with both glandular and non-glandular chambers, renal pore and gonopore closely set but clearly separate. Labial palps falcate and large, gills or demibranchs la- mellar, inner gill larger than outer gill, both inner and outer gills free from mantle posterior to pallial line. Both EX ^.^: ^d.r't-'^r' Figure 2. Photomicrograph of a transverse section through the posterior portion of the mantle of Margaritifera hembeli showing the partial!) contracted diaphragmatic septum (DS), which separates the exhalent (EX) and inhalent (IN) chambers, SO X. lamellae of each gill held together b> solid, separate interlamellar junctions (figure 1, ILJ), lined with squa- mosal epithelium and composed of loose connective tis- sue and fine fibers that are more muscular appearing than collagenous (in M. margaritifera. see Smith, 1979a). Interlamellar junctions for the most part arranged in oblique rows in typical margaritiferine fashion (Ort- mann, 1912; Smith and Wall. 1983: fig. lb), similar to gills of A/. niarr!ana<'(Ortmann, 1912:235). Gill junctions are somewhat patternless along lower margin and an- terior and posterior extremities of each gill plate. Mantle lobes free all around, no indication of division of exhalent region of mantle margins into .separate anal and supra-anal apertures. Inhalent and exhalent cham- bers separated posteriorly by diaphragmatic septa (figure 2, DS), and though not observed in the living animal, are presumed to function similar to M. margaritifera (Smith. 1980) Inhalent margin of mantle with densely pigmented papillae, exhalent region pigmented, with crenulate margin. Gonadal Activity and Sexuality .All animals examined histologicalK were sexually ma- ture, including several small specimens ranging in shell length from 49 to fj9 mm (believed to be from 6 to 9 D. G. Smith 1988 Page 161 'f ^ ^i V >*.. s' Figures 3-6. Photomicrographs of histological sections through male and female gonads of Margaritifera hembeli. 3. Gonad of a male specimen of M. hembeli collected in Februar\, following spawning of gametes, 65 x. 4. Gonad of a female specimen collected in February following spawning, 65 x. 5. Gonad of a male specimen of M. hembeli collected in October and showing male gametes which have filled the entire gonadal stroma, 100 x . 6. Gonad of a female specimen of M. hembeli collected in October and containing fully developed ova, 100 x . years old on the basis of shell annuli). This would suggest that M. hembeli matures at an earlier age than North American M. margaritifera (Smith, 1979b). No evidence of hermaphroditism was observed. Although no gravid females were among the available specimens, a specific reproductive cycle was indicated by the gonads of sectioned specimens. Animals collected in Februarv', March, and April showed characteristic post- spawning features (figures 3, 4) including partial or com- plete occlusion of gonadal acini by granules, presumed pycnotic cells, and unspawned gametes in various stages of development or cytolysis. Animals collected in June showed little change from April specimens indicating that complete resorption of reproductive tissues, corre- sponding to an undifferentiated stage of non-reproduc- tive activity, apparently does not occur. By early Octo- ber, gonadal activity is resumed and sex cells, including the latter stages of spermatogenesis and oogenesis, are abundant within all observed acini (figures 5, 6). It is therefore hypothesized that the oviposition of eggs into marsupial demibranchs and the spawning of male ga- metes takes place sometime between late November and late December with release of larvae occurring in late December or January. Based on examined specimens, there is no evidence that production of glochidial larvae takes place at any other part of the year. Visceral Nerve Anatomy In M. hembeli, the first pallial bifurcation (figure 7, BI) of the posterior nerve is well anterior of the mantle nerve separation, usually arising from the visceral ganglion it- self at a point near the origin of the posterior nerve cord (figure 7, PNC). Some variation exists in the position of this bifurcation relative to the visceral ganglion. The overall pattern differs from that observed in other eastern North .American margaritiferids including A/, marrian- ae. in which the first bifurcation is normally posterior of the visceral ganglion, but similar to that observed in Cumberlandia monodonta (Smith, 1980, unpublished data). Moreover, in both M. hembeli and M. marrianae, the accessory nerve, which is typically present in M. Page 162 THE NAUTILUS, Vol. 102, No. 4 VG PNC OES Figures 7-9. .\natoniy of the visceral nervous system and stomacli of Margarilifcra hcmbeli. 7. Visceral ganglion (VCJ) of M. hemheli. 20 x. 8. Morphology of the stomach roof of M. hembeli, 5 x . 9. Morphology of the stomach floor of M. hemheli. 5 x . APR, anterior protractor muscle; ASA, anterior sorting area; .ASR, anterior sorting area of roof; BI, first pallial bifurcation; BN, branchial nerve; C, commissure to cerebro- pleural ganglion; MN, mantle nerve; PNC, posterior nerve cord; OES, esophagus; PSf\, posterior sorting area; HD, right duct; RSA, right side sorting area; T, major typhlosole. margaritifera and C. monodonta (Smith, 1980), is almost aKva> s absent, being observed only once in M. marrianae (Smith, unpublished data). Stomach Anatomy In addition to the posterior sorting area, which is typical of other eastern North American margaritiferids, the stomach roof of M. hembeli contains a well developed anterior sorting area and a continuation of the posterior sorting area extending along the right side of the stomach roof and separated from the anterior sorting area by a ridge (figure 8). The floor of the stomach interior (figure 9) is char- acterized by an anterior sorting area that is somewhat similar to M. marrianae (Smith, 1986; fig. 4b); however, the right side sorting area of M. hembeli is completely unlike ,V/. marrianae in that a distinct platform is absent in A/, hembeli and the sorting ridges run primariK lat- eralK , rather than in the anterior-posterior pattern seen in M. marrianae. A groove sets off the right side sorting area from the anterior sorting area in A/, hembeli and the morphologN of the stomach Door sorting areas of M. hembeli can be considered more similar to M. marga- ritifera in overall appearance than to other eastern North .\merican species. DISCUSSION As demonstrated by anatomical investigations of the vis- ceral nervous system and the stomach (this studv), and conchological differences discussed elsewhere (Johnson, 1983; Smith, 1983), A/, hembeli and A/, marrianae clear- 1\ represent distinct lineages within the genus Marga- ritifera. Although both species have lateral teeth, these teeth are also present in M. auricularia (southern Europe) and A/, laosensis (southeast .\sia). Lateral teeth may therefore represent structures that have arisen separately in different "stocks of margaritiferid species, or ma> be symplesiomorphies indicative of an ancestral relation- ship. The presence of a corrugated surface of the posterior slope of the shell (weakK expressed in A/, hembeli) and the close geographical proximit\ of these two species are the strongest lines of evidence indicating a relationship between them. Ne\ ertheless, the pattern of \isceral nerve bifurcation and stomach morphologv in A/, hembeli and M. marrianae show interspecific variation as great as that observed between either of these two species and M. margaritifera or C. monodonta. Biochemical data of the sort de\eloped for M. margaritifera. C. monodonta, and A^. hembeli b> Davis and Fuller (1981) is not avail- able for M. marrianae, precluding a comparison of ge- netic distances among the four species. However, the available biochemical data i Davis and Fuller, 1981), combined u ith anatomical information presented in this stud) and elsewhere (Smith, 1980, 1986), clearK supports the concept that the North .American species of the Mar- garitiferidae have been isolated from one another for a considerable period of time (Smith, 1976). ACKNOWLEDGEMENTS I thank Malcolm F. Vidrine, Mark E. Gordon, and James E. Williams for gracioiisK- supplying me with the pre- served specimens used in this studv. Mark E. Gordon kiiulK read an early draft of the paper. D. G. Smith 1988 Page 163 LITERATURE CITED Conrad, T. A. 1838. Monography of the family Unionidae, or naiades of Lamarck (fresh water bivalve shells) of North America, Numbers 10, 11. Philadelphia, PA, p. 81-102 Davis, G. M. and S. L. H. Fuller. 1981. Genetic relationships among Recent Unionacea (Bivalvia) of North ,\merica. Malacologia 20:217-2.53. Humason, G. L. 1979. .Animal tissue techniques, 4th ed W . H. Freeman & Co., San Francisco, 661 p. Johnson, R. I. 1983. Margaritifera marrianae, a new species of Unionacea (Bivalvia: Margaritiferidae) from the Mo- bile-.Alabama-Coosa and Escambia River systems, Ala- bama. Occasional Papers on Mollusks (Harvard Universitv) 4:299-304. Ortmann, .\. E. 1912. Notes upon the families and genera of the najades. .Annals of the Carnegie Museum 8:222-.365. Smith, D. G. 1976. The distribution of the Margaritiferidae: a re\iew and a new synthesis Bulletin of the .American Malacological Union 1976:42 (abstract). Smith, D. G. 1979a. Marsupial anatomy of the demibranch of Margaritifera margaritifera (Lin. ) in northeastern North America (Pelecypoda: Unionacea). Journal of Molluscan Studies 4.5:39-44. Smith, D. G. 1979b Se.xual characteristics of Margaritifera margaritifera (Linnaeus) populations in central New En- gland. Veliger 21:381-383. Smith, 1) (; 1980 Anatomical studies on Margari/i/era mar- garitifcra and Cumherlandia monodonia (Mollusca: Pe- lec> poda: Margaritileridae). Zoological Journal of the Lin- nean Society (i9:257-270. Smith, D. G. 1983. On tlie so-called mantle muscle scars on shells of the Margaritiferidae (Mollusca: Pelecypoda). with observations on mantle-shell attachment in the Unionoida and Trigonioida. Zoologica Scripta 12:67-71. Smith, D. G. 1986. The stomach anatomy of some eastern North .American Margaritiferidae (Unionoida: L'niona- cea). .American Malacological Bulletin 4:13-19. Smith, D. G. and W. P. Wall. 1983. The Margaritiferidae reinstated: a reply to Davis and Fuller (1981), "Genetic relationships among Recent Unionacea (Bivalvia) of North America." Occasional Papers on Mollusks (Harvard Uni- versity) 4:321-330. Stewart, J. H. 1988. Endangered and threatened wildlife and plants; final endangered status for the Louisiana pearl shell "Margaritifera hembeli." Federal Register 53:3567-3570. \'idrine. M. F. 1985. Fresh-water mussels (Unionacea) of Louisiana; a zoogeographical checklist of post-1890 rec- ords. The Louisiana Environmental Professional 2:50-59. THE NAUTILUS 102(4): 164-166, 1988 Page 164 The Two Printings of J. F. Gmelin's Systema Naturae, 13th Edition (1788-96) Alan R. Rabat Deparlmenl of Mollusks Museum of Comparative Zoology Harvard University Cambridge, MA 02138, USA Richard E. Petit Research Associate Department of Invertebrate Zoology National Museum of Natural History Smithsonian Institution Washington, DC 20560, USA One of the more important 18th century reference works in systematics is J. F. Gmelin s l.'3th edition of Linnaeus' Systema Naturae. This work represented a considerable updating of and expansion upon the 12th edition of the Stjstema Saturae (Linnaeus, 1767). Gmelin not only pro- \ ided additional bibliographic references for the species described by Linnaeus, but he also described numerous new species, using the same format as had Linnaeus. Gmelin's magnum opus was published in three volumes, comprising 10 parts altogether: Regntim Animalium (7 parts); Regnum VegetaMe (2 parts); and Regnum La- pideuni (1 part). For comments on the structure and content of Gmelin's work, see Dodge (1958:157-158). Few systematists, however, have realized that Gme- lin's work actually underwent two separate printings. The initial German printing was by Georg. Emanuel. Beer of Lipsiae [= Leipzig]; the later French printing was by J. B. DelamoUiere (subsequently as Bernuset, Delamolliere, Falque et Soc. ) of Lugduni [= Lyon]. Both, of course, were written in Latin. Hopkinson (1907) provided a valuable collation of the Lipsiae printing, based on an analysis of various German literature abstracts and review publications. He noted that only the first part in the two multi-part volumes had a date on the title page and that this date "did not apply to the whole of the parts in that \olume " (Hopkinson, 1907:1036), since the later parts were published in fol- lowing years. Hopkinson did not refer to the Lugduni printing. Agassiz (1852:69) listed this work as "Leipz. 1788-1793,. . . Lugduni, 1789-1796." Engelmann (1846: 103) provided the same dates as had Agassiz, but erro- neously gave the place of publication as "Lugd. Batav." which is actually Leiden [= Lugduni Batavorum]. Sher- born (1902:.\.\xv) gave the same dates, made the same geographical transposition as had Engelmann, and spec- ified that the second printing was a reprint of the first. Hulth (1907:13) and Soulsby (1933:16, 50) provided a partial collation ol these two printings; however, their dates are based solely on those stated on the title page for the first part of each of the two multi-part volumes. Stafleu and Cowan (1976:956) briefly mentioned the two printings, and noted for the Lugduni printing: type reset, no copy seen . Frequently , librarx copies will have the same date stamped on the binding of each part or hand-written on the first page of each part; this is in- correct. The important facts are that the Lugduni print- ing was published after the Lipsiae printing, and was printed from reset type w hich resulted in a number of differences due to printer s error. Therefore, the date of publication of each part of the Lugduni printing must post-date that of the relevant part of the Lipsiae printing. L'nfortunately , we have not been able to determine the date of publication for the succeeding parts of the Lugduni printing (only for the first part in the multi- part volumes). However, we present this comparison here in order to alert s\ stematists to the existence of these two printings. Should the reader know of further bibliograph- ical sources bearing on this matter, we would greatly appreciate hearing from them. Herein we present as complete a collation as possible of the two printings of Gmelin's Systema Saturae. based on Hopkinson (1907) and on our examination of complete sets of this work in the libraries of the Museum of Com- parative Zoology , the British Museum (Natural History), and the Museum National d Histoire Naturelle, Paris. Gmelin, jo. Prid. [Joliann P^iedrich]. 1788-1793. Ca- roli a Linne, Systema Naturae per Regna Tria Naturae, Secundum Classes, Ordines, Genera, Species, cum cha- ractcribus, diftcrentiis, synonymis, locis. Editio Decima Tertia, Aucta, Reformata. Georg. Emanuel. Beer, Lip- siae; [Second printing, 1789-1796], J. B. Delamolliere, Lugduni. Tomus 1, REGNUM ANIMALIUM 1(1) Mammalia to Aves Picae, pp. xii -I- 1-500 Lipsiae, 1788; Lugduni, 1789. 1 (2) Aves Anseres — A\es Passeres. pp. 501-1032 Lipsiae, 1789; Lugduni (post 1789?). I (3) Amphibia — Pisces, pp. 1033-1516 Lipsiae, 1789; Lugduni (post 1789?). A. R. Kabat and R. E. Petit 1988 Page 165 I (4) Insecta General, Coieoptera — Hemiptera, pp. 1517- 2224 Lipsiae, 1790; Lugduni (post 1790?). I (5) Insecta Lepidoptera — Aptera, pp. 2225-3020 Lipsiae, 1790; Lugduni (post 1790?). 1(6) Vermes, pp. 3021-3910 Lipsiae, 1791; Lugduni (post 1791?). 1(7) Inde.x 1-3, pp. 3911-4120 Lipsiae, 1792; Lugduni (post 1792?), Tomus II, REGNUM VEGETABILE II (1) Monandria to Polyandria, pp. .\1 + 1-884 Lipsiae, 1791; Lugduni, 1796. II (,2) Didynamia to Cryptogamia, pp. 885-1662 Lipsiae, 1792; Lugduni (1796 or later?). Tomus 111, REGNUM LAPIDEUM 111, pp. 1-476, plates 1-3 (of crystals) Lipsiae, 1793; Lugduni. 1796. It has been our experience that molluscan taxonomists who have used Gmelin's work have usually referred sole- ly to the Lipsiae printing. Among others, these include Dodge (1958:157-158); and Kohn (1966) who provided biographical information on Gmeiin and a useful critique of his work. .\n example of the taxonomic problems that can arise with respect to the two printings of Gmelin's \\ ork is that of certain species of Cancellariidae (Gastrop- oda) reviewed by Petit (1984). For Buccinum piscato- rium Gmeiin. 1791 (p. 3496), the Lipsiae printing gave two references: "List. Conch, t. 1024 f. 89"' and "Martin. Conch. 4. t. 124 f. 1151, 1152". Based on this, Petit chose the figures from the latter reference (i.e., Chemnitz, J. H., 1780, Neues Systetnatisches ConchyHen-Cabinet , \"ol. 4, Nurnberg) to be representative of this species. Subsequently, A. Verhecken [in litt.) inquired as to how the Chemnitz illustration could be used in this manner since it was not cited by Gmeiin. In later correspondence, N'erhecken advised that he had found that he was re- ferring to a cop)- of the Lugduni printing. In that printing only one reference, the aforementioned "List. Conch, t. 1024 f. 89" (i.e.. Lister, M.. 1692/1770, Historiae sive Synopsis Methodicae Conchyliorum, London), was giv- en for the species in question; the Chemnitz reference being omitted. ObviousK', the omission of the reference to Chemnitz was a printer's error, as a comparison of the two printings makes it evident that the type was reset and errors were made. Incidentally, the third volume of this work (the Reg- num Lapideum) was placed on the Official Index of Rejected and Invalid Works in Zoological Nomenclature (along with the related sections of Linnaeus and of Tur- ton), since the "generic names of fossil animals used in these works actually corresponded to the classes of Recent animals (ICZN, 1954, Opinion 296). We conclude that (1) since the Lipsiae printing was published first, it should serve as the basis for discussion of Gmelin's species; (.2) the Lugduni printing should be treated as a reprint (or reissue) in which errors occur, and not as a "second edition "; (3) systematists who are studying species described by Gmeiin should compare the two printings in order to uncover any discrepancies with respect to species descriptions or references. ACKNOWLEDGEMENTS Mr. Andre Verhecken, Mortsel, Belgium, first brought the discrepancy in the Gmeiin citations to our attention, and then followed up with information on the existence of the two printings. His interest and assistance is greatly appreciated. We thank the librarians of the Museum of Comparative Zoology, the British Museum (Natural His- tory), and the Museum National d'Histoire Natureile, who allowed us to examine the sets of Gmelin's work in their collections. A number of other hbraries were checked for this work; most had only partial sets of one or the other printing which did not yield additional useful in- formation. Prof. Kenneth J. Boss provided a helpful re- view of this manuscript. LITERATURE CITED Agassiz, L. 1852. Bibliographia Zoologiae et Geologiae, Vol. 3 (of 4). Ray Society, London, 657 p. Dodge, H. 1958. .\ historical review of the mollusks of Lin- naeus. Part 6. The genus Trochus of the class Gastropoda. Bulletin of the American Museum of Natural History 116(2):153-224. Engelmann, W. 1846. Bibliotheca Historico-Naturalis. Ver- zeichniss der Biicher iiber Naturgeschichte . . . Erster Band. Verlag von Wiihelm Engelmann, Leipzig, x -I- 786 p. Hopkinson, J. 1907. Dates of publication of the separate parts of Gmelin's edition (13th) of the 'Systema Naturae' of Linnaeus. Proceedings of the Zoological Society of London 1907(49):1035-1037. Hulth, J. M. 1907. Bibliographia Linnaeana: materiaux pour servir a une Bibliographie Linneenne. Kungliga Veten- skaps Societeten I Upsala, 170 p. -H 11 pis. International Commission on Zoological Nomenclature, 1954. Opinion 296. Suppression, under the Plenary Powers, for nomenclatorial purposes, of volume 3 (Regnum Lapi- deum) of the Twelfth Edition of the Systema Naturae of Linnaeus published in 1768 and of the corresponding vol- ume in the Houttuyn (1785), Gmeiin (1793) and Turton U806) editions of the above work. Opinions and Decla- rations rendered by the International Commission on Zoo- logical Nomenclature 8(13):167-178. Kohn, A. J. 1966. Type specimens and identity of the de- scribed species of Conus III. The species described by Gmeiin and Blumenbach in 1791. The Journal of the Lin- nean Societv of London, Zoology 46(308):73-102, pis. 1-3. Linnaeus, C. 1766-67. Systema Naturae, per Regna Tria Na- turae, . . . Editio Duodecima Reformata. Direct. Laur. Sal- vii, Holmiae. Regnum Animale, 1328 -t- 36 p. Petit, R. E. 1984. Some early names in Cancellariidae. Amer- ican Malacological Bulletin 2:57-61. Sherborn, C. D. 1902. Index Animalium sive index nominum quae ab .\.D. MDCCL\'III generibus et speciebus ani- malium imposita sunt . . Sectio Prima. L niversity Press, Cambridge, Ix + 1195 p. Page 166 THE NAUTILUS, Vol. 102, No. 4 Soulsby, B. H. 1933. A catalogue of the works of Linnaeus Stafleu, F. A. and R. S. Cowan. 1976 [in 1976-86]. Taxonomic (and publications more immediately relating thereto) pre- literature: a selective guide to botanical publications and served in the libraries of the British Museum (Bloomsbury) collections with dates, commentaries, and types. Second and the British Museum (Natural History) (South Ken- Edition. Regnum X'egetabile; Bohn. Scheltema & Holke- sington). British Museum (Natural History), London, 2nd ma, Utrecht, \'ol. 1 (of 6):xl + 1136 p. ed., p. xii -I- 1-312; 7 pis. 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