7 December 1988 PROC. BIOL. SOC. WASH. 101(4), 1988, pp. 730-740 NOTES ON ANTROSELATES HUBRICHT, 1963 AND ANTROBIA HUBRICHT, 1971 (GASTROPODA: HYDROBIIDAE) Robert Hershler and Leslie Hubricht Abstract. —Antroselates Hubricht, 1963 and Antrobia Hubricht, 1971, mono- typic cavesnail genera from eastern United States, are redescribed. The presence of a spermathecal duct in the female reproductive system of these snails in- dicates that, contrary to earlier opinions, they belong to the Hydrobiidae: Lit- toridininae. Both genera are well-differentiated members of the Cochliopina Morrison, 1946 group, characterized by possession of trochoidal shells and simple penes. The monotypic genera Antroselates and tate surface lined by spiral grooves. Aper- Antrobia are poorly known members of the ture enlarged, with expanded outer lip. Um- North American aquatic cavesnail (Gas- bilicus narrowly to broadly open. tropoda: Hydrobiidae) fauna. Initial de- Operculum paucispiral, with rapidly ex- scriptions of these unusual-shelled snails panding whorls. Animal blind, unpigment- lacked critical details from soft-part mor- ed. Basal cusps of central radular teeth phology and speculations on their affinities emerging from lateral angles. Cephalic ten- have varied considerably. Antroselates, for tacles without hypertrophied ciliary tufts. instance, was initially considered a hydro- Ctenidium broad and elongate, with ca. 25 biid (Hubricht 1963:138), but also has been filaments. Intestine with coil in pallial roof. placed in the Micromelaniidae (Taylor 1966: Penis simple, flagellate, non-glandular; sur- 171, Burch 1982:3). During the course of face of distal portion striated. Females ovip- an ongoing review of North American cav- arous. Spermathecal duct present, connect- esnails, we examined what may be the only ing posteriorly with albumen gland and alcohol-preserved material available for anteriorly with capsule gland. Oviduct these genera and determined that, contrary opening into ventral surface of albumen to all previous assertions, both are well-dif- gland. Bursa copulatrix large, positioned ferentiated members of the Cochliopina partly posterior to albumen gland. group of Hydrobiidae: Littoridininae (Her- Remarks. — Placement of this genus in the shler 1985). Redescriptions of Antroselates Micromelaniidae was based on the incorrect and Antrobia follow. observation that the central radular teeth lacked basal cusps (Hubricht 1963:138). We Antroselates Hubricht, 1963 assign the genus to the Hydrobiidae: Lit- toridininae on the basis of possession of a Antroselates Hubricht, 1963:138. Type spermathecal duct in the female reproduc- species, Antroselates spiralis Hubricht, tive system (see Davis et al. 1982, Hershler 1963, by monotypy and original desig- 1985). The globose shell and simple penis nation. indicate assignment to the informal Coch- Diagnosis.— Shell small, solid, trochoid- liopina group (Hershler 1985). Affinity with low conic, with 4.5 rounded whorls sculp- Antrobia is indicated by similarity of pro- tured with numerous elevated spiral lines. toconch sculpture and duct arrangements in Protoconch tilted or depressed, with punc- the pallial oviduct complex (including VOLUME 101, NUMBER 4 731 unique connection between spermathecal caecal chamber. Intestinal loop filling pos- duct and albumen gland). These snails are, terior half of pallial roof (Fig. 2b). Osphra- however, separable by differences in shell, dium filling 25-33% of ctenidium length. penial and radular morphology. Testis (Ts, Fig. 2b) massive, covering stomach and extending from posterior edge Antroselates spiralis Hubricht of prostate gland (overlapping most of Figs. 1, 2, 3a-c, 4 stomach) almost to posterior end of animal. Branches of testis bearing numerous grape- Antroselates spiralis Hubricht, 1963:138- like lobes and draining to narrow, thin vas 139, pi. 8, figs, a, b; (Holotype FMNH efferens. Seminal vesicle consisting of a few 116916).-Burch 1982:108, fig. 108. thickened coils ventral to anterior testis. Material examined. — Kentucky. Ed- Prostate gland (Fig. 2d) thickened, near-cir- mondson County: Echo River Spring, cular in outline; almost entire length posi- Mammoth Cave National Park, USNM tioned in pallial roof. Vas deferens entering 673526 (paratypes), USNM 673527 (para- and exiting antero-ventral portion of gland; types); River Styx, Mammoth Cave, Mam- anterior portion of duct having thickened moth Cave National Park, UF 40624 (al- coil. Penis emerging from behind right ce- cohol series [unrelaxed]). phalic tentacle, large relative to head (Fig. Description.—Shell (Fig. 1) 4.3-5.2 mm 2c), with a tight clockwise coil. Penis (Fig. in height, slightly taller than wide. Whorls 3a) unciliated, vermiform, with short distal- shouldered adapically, sutures slightly in- most section tapering gently. Vas deferens dented. Body whorl enlarged, spire rela- having thickened coils in base of penis; duct tively small. Shell white-clear, translucent, undulating in penis. Distal half of structure with amber periostracum. Surface typically striated (Fig. 3a), with surface consisting of eroded with small holes. Protoconch surface broad ridges alternating with narrow fur- slightly pitted; spiral grooves (Fig. 1 d) fairly rows (Fig. 3b). Terminus (Fig. 3c) thick- broad and slightly depressed. Spiral lines of ened, smooth. Opening of vas deferens ter- irregular height crossing strong growth lines minal, simple. on teleoconch (Fig. lb, c). Aperture ellip- Ovary a simple lobed mass filling about soidal, longer than wide, rounded above and one half whorl behind posterior edge of somewhat angled below, and tilted relative stomach. Albumen and capsule glands (Ag, to coiling axis, with anterior side advanced. Cg, Fig. 2e) about equal in length; capsule Inner lip somewhat thickened and reflected gland bipartite (posterior section much below, broadly adnate to body whorl above. longer). Oviduct (Ov) with single, thickened Outer lip thin. Operculum (Fig. 2a) thin, coil on left side of albumen gland. Kidney- amber-colored, with pronounced growth shaped bursa copulatrix pressed against and lines. slightly overlapping posterior edge of al- Animal of three whorls (Fig. lb). Proxi- bumen gland. Bursa duct narrow" (Dbu). mal portions of tentacles without any ex- Seminal receptacle (Sr) small, almost duct- ternally visible vestiges of eyespots. Gen- less, pear-shaped, positioned on left side of eralized formulae of radular teeth (Fig. 4): albumen gland and slightly overlapping central, 5(6)-l-5(6)/3-3; lateral, 4(5)-1-4(5); bursa. Oviduct without connection to al- inner marginal, 15-18; outer marginal, 12- bumen gland. Communication to latter 16. Central teeth trapezoidal; basal cusps achieved by short duct emerging from sper- small, central cusps only slightly enlarged. mathecal duct (Dsd, Fig. 2f) slightly anterior Lateral teeth with enlarged, hoe-like central to point where oviduct joins seminal recep- cusps (Fig. 4b). Stomach slightly longer than tacle duct. This unique arrangement implies style sac. Posterior edge of stomach without that oocytes travel (anteriorly) a short dis- 732 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON Fig. 1. SEM micrographs of shells of Antroselates spiralis Hubricht, USNM 673527 (paratypes): a, (Shell height, 4.95 mm); b, Dorsal aspect, showing well-developed spiral lines (shell height, 3.12 mm); c, Apical whorls (bar = 0.43 (im); d, Protoconch (bar = 176 iim). tance through the spermethecal duct before large stones in running water" (Hubricht entering duct to albumen gland. Spermathe- 1963:139). The species was not found by cal duct (Sd) fairly wide, pressed against the senior author during a 1987 trip to the capsule gland. Spermathecal duct entering Mammoth Cave area. anterior capsule gland; genital aperture (Ga) simple, terminal. Antrobia Hubricht, 1971 Distribution.—Found in a few caves and Antrobia Hubricht, 1971:95. Type species, springs in vicinity of Mammoth Cave Na- Antrobia culveri Hubricht 1971, by tional Park, Kentucky, as well as in a cave monotypy and original designation. stream in adjacent Indiana (Fig. 5; Hubricht 1963). Snails "found on the undersides of Diagnosis.— Shell small, low conical, VOLUME 101, NUMBER 4 733 1.0 mm 1.0 mm Jnc Epc Fig. 2. Morphology of Antroselates spiralis Hubricht, UF 40624: a, Dorsal view of operculum; b, Dorsal view of male (head-foot removed); c, Dorsal view of head and penis; d, Right lateral view of prostate gland; e, Left lateral view of pallial oviduct complex; f, Left lateral view of bursa copulatrix, seminal receptacle (rotated to expose underlying structures), and associated ducts. Only the anterior portion of the albumen gland is shown. Ag = albumen gland; Avd = anterior vas deferens; Bu = bursa copulatrix; Cg = capsule gland; Dbu = duct from bursa copulatrix; Dg = digestive gland; Dov = duct connecting oviduct and spermathecal duct; Epc = posterior end of pallial cavity; Ga = genital aperture; In = intestine; Jnc = juncture between anterior vas deferens and "neck"; Ov = oviduct; Pr = prostate gland; Pvd = posterior vas deferens; Sd = spermathecal duct; Sr = seminal receptacle; Sts = style sac; Ts = testis. 734 PROCEEDINGS OF THE BIOLOGICAL SOCIETY OF WASHINGTON Fig. 3. SEM micrographs of critical point dried penes of Antroselates spiralis Hubricht, UF 40624 (a-c) and Antrobia culveri Hubricht, LH coll. (d): a, Dorsal view of penis (bar = 37 ^m); b, Close-up of striated surface (bar =213 fim); c, Close-up of penial tip, showing simple terminal opening (bar = 25 /um); d, Dorsal view of penis showing