70 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY FIGURE 27.—<strong>Pyrgulopsis</strong>: a-c, P. wongi (a, holotype, USNM 860403, 2.0 mm; b, c, opercula, USNM 857941, bars = 0.33 mm, 0.3 mm); d-f, P. agarhectus {d, shell, FSM uncat, 2.1 mm; e,f, opercula, FSM 189468, bars = 0.25 mm, 0.3 mm); g-i, P. arga (g, shell, FSM 22287, 3.2 mm; h, i, opercula, FSM uncaL, bar = 0.43 mm).
NUMBER 554 71 filament, extending slightly onto right edge <strong>of</strong> penis. Dgl elongate, curving from right edge near base <strong>of</strong> lobe transversely across penis, generally raised, usually fused with Dg2; Dg2, when separate, horizontal, short to medium length; Dg3 narrowly elongate, bome on moderate swelling. Dorsal penis also with 2-5 small glands in central region (variable in size and placement, sometimes reduced in number through apparent fusion) between Dgl-Dg2 and base <strong>of</strong> lobe. Terminal gland elongate, transverse, curved, covering distal edge <strong>of</strong> lobe (mostly ventral surface). Ventral gland stalked, sub-terminal, positioned just proximal to lobe; accompained by smaller, stalked gland (sometimes greatly reduced) just proximal to above (sometimes with third smaller gland on ei<strong>the</strong>r side <strong>of</strong> above). Filament dark. Ovary, 0.75-1.0 whorl, slightly overlapping posterior stomach chamber. Albumen gland without a pallial section. Capsule gland as long as albumen gland. Genital aperture a subterminal slit with short vestibule. Coiled oviduct a broad, open, horizontal loop a moderate distance behind pallial wall. Oviduct and bursal duct join well behind pallial wall. Bursa copulatrix pyriform, posterior end pointed, as long or longer than and almost as wide as (92%) albumen gland, with about 67% <strong>of</strong> length posterior to gland. Bursal duct narrow proximally, broadening at junction with oviduct, short. Seminal receptacle pouch-like, short, overlapping anterior bursa copulatrix, extending to posterior edge <strong>of</strong> albumen gland. TYPE LOCALITY.—Unnamed western spring tributary to Pine Creek, Birchim Canyon, Owens Valley, Inyo County, California (T 6S, R 3 IE, SE1/4 sec. 9). DISTRIBUTION.—Pluvial Owens River drainage, and several endorheic basins to <strong>the</strong> east (Deep Springs, Fish Lake, Huntoon Valleys), California-Nevada. MATERIAL EXAMINED.—USNM 857941 (paratypes). Eastern <strong>American</strong> Species <strong>Pyrgulopsis</strong> agarhecta (Thompson, 1970) Marstonia agarhecta Thompson, 1970:243, figs, la-f, 11.—Thompson, 1977:130, figs. 3b, 23, 24, 25h—Burch, 1982:27, figs. 214, 232—Turgeon et al., 1988:61. <strong>Pyrgulopsis</strong> agarhecta.—Hershler and Thompson, 1987:29.—USDI, 1991b:58821. DIAGNOSIS.—Shell conical, medium-sized, inner lip usually incomplete, umbilicate. Penial filament medium length, lobe short. Penial ornament a variably shaped terminal gland. DESCRIPTION.—Shell (Figure 21d) conical; height, 2.3-2.7 mm; whorls, 4.5. Early protoconch strongly punctate adapically. Teleoconch whorls strongly convex, weakly shouldered; sculpture <strong>of</strong> faint growth lines and very weak spiral striae. Aperture ovate, medium-sized, slightly angled above, adnate to body whorl. Parietal lip usually incomplete or a weak glaze; columellar lip thin, slightly reflected. Outer lip prosocline. Umbilicus open. Periostracum light brown. Operculum (Figure 27e,f) broadly ovate, very thin, light amber (almost pale), slightly indented along outer edge; nucleus slightly eccentric; dorsal surface weakly frilled. Attachment scar margin slightly thickened along inner edge; callus very weak. Central radular tooth (Figure 41a) with slightly indented dorsal edge; lateral cusps, 3-5; central cusp weakly rounded, broader and longer than laterals; basal cusps, 1 (second, weak outer cusp sometimes present), elongate, with weak dorsal support. Basal process rounded, weakly excavated. Lateral margins slightly thickened; neck near absent. Head-foot unpigmented. Pallial ro<strong>of</strong> with two black streaks along edges <strong>of</strong> ctenidiurn. Streaks darkened and usually connected anteriorly; streak along osphradial margin short Dorsal edge <strong>of</strong> glandular oviduct lined with small black granules. Testis black. Ctenidial filaments, 22, tall, narrow. Osphradium elongate (33%), centered posterior to middle <strong>of</strong> ctenidial axis. Kidney opening slightly thickened. Stomach caecum broadly triangular, large. Testis, 1.5 whorls, overlapping posterior stomach. Coils <strong>of</strong> seminal vesicle extremely thickened, conspicuously overlapping stomach. Prostate gland ovoid, with short pallial section; pallial vas deferens simple. Penis (Figure 52a) medium-sized, extending only slightly beyond mantle edge; base short; filament medium length, gently tapering; lobe short, broad. Terminal gland large, variably shaped, bome on ventral surface <strong>of</strong> lobe distally. Penis unpigmented. Ovary, 1 whorl, slightly overlapping posterior stomach. Pallial albumen gland large (30%). Capsule gland slightly longer than albumen gland. Genital aperture sub-terminal, short, with vestibule. Coiled oviduct <strong>of</strong> two broadly overlapping horizontal loops just behind pallial wall. Oviduct and bursal duct join anterior to loop in posterior pallial cavity. Bursa copulatrix pouch-like, short (28%), narrow (25%), extending almost to posterior edge <strong>of</strong> albumen gland; anterior bursa partly embedded in gland. Bursal duct scarcely narrower than bursa copulatrix, embedded in albumen gland, more than twice as long as bursa copulatrix. Seminal receptacle stubby, short, positioned lateral to proximal bursal duct along ventral edge <strong>of</strong> albumen gland. TYPE LOCALITY.—Bluff Creek, 10.4 miles south-sou<strong>the</strong>ast <strong>of</strong> Hawkinsville, Pulaski County, Georgia. Holotype, FSM 20528; paratypes, FSM 20569. DISTRIBUTION.—Known only from <strong>the</strong> type locality, Ocmulgee River drainage (Atlantic Coastal; Thompson, 1977, fig. 20). REMARKS.—This snail differs from similar P. castor and P. halcyon by its more elongate shell and absence <strong>of</strong> a ventral penial gland. MATERIAL EXAMINED—FSM 189468, FSM 193381 (topotypes). <strong>Pyrgulopsis</strong> arga (Thompson, 1977), new combination Marstonia arga Thompson, 1977:119, figs. la,b, 4f, 6-8. 25b—Burch, 1982: 27, figs. 215, 233.—Turgeon et al., 1988:61.
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