A Review of the North American Freshwater Snail Genus Pyrgulopsis

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58 SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY FIGURE 23.—Western Pyrgidopsis: a-c, P. pecosensis. USNM 873131 (a, shell, 3.2 mm; b,c, opercula, bar = 0.38 mm); d-f, P. perturbata (d, holotype, USNM 860407, 3.4 mm; e,f, opercula, USNM 857990, bars = 0.43 mm, 0.38 mm); g-i, P. pilsbryana, USNM 858279 (g, shell, 2.6 mm; hj, opercula, bar = 0.33 mm).
NUMBER 554 59 REMARKS.—The small size and ovate shape of these empty western shells suggest membership in Pyrgulopsis. This species is distinguished from Pyrgulopsis brandi, which was described from extant populations occurring in the same region, by its squatter shell and thin apertural lip. Pyrgulopsis pecosensis (Taylor, 1987), new combination Fontelicella pecosensis Taylor, 1987:27, fig. 12. "Fontelicella" pecosensis.—USDI, 1991b:58819. DIAGNOSIS.—Shell ovate- to narrowly conic, medium-sized, umbilicate. Penial filament short; lobe short, broad. Penial ornament a short Dgl, small Dg3 borne on lobule; curved, elongate, transverse terminal gland; and ventral gland. DESCRIPTION.—Shell (Figure 23a) ovate- to narrowly conic; height, 2.0-2.9 mm; whorls, 4-5. Early protoconch weakly punctate, otherwise near smooth except for faint spiral lines. Teleoconch whorls moderately convex, sometimes weakly shouldered; sculpture of weak growth lines and occasionally weak spiral lines. Aperture ovate, angled above, usually adnate to body whorl. Inner lip complete, thickened; columellar lip sometimes slightly reflected. Outer lip thinner, prosocline. Umbilicus shallowly rimate or perforate. Periostracum tan. Operculum (Figure 23b,c) ovate, amber, darker in nuclear region; nucleus slightly eccentric; dorsal surface strongly frilled. Attachment scar margin broadly thickened between nucleus and inner edge (extending slight distance along edge), otherwise very weak-smooth; callus weak. Central radular tooth (Figure 38i) with moderately indented dorsal edge; lateral cusps, 6-7; central cusp rounded, considerably longer and broader than laterals. Basal cusps, 1, short, with slight dorsal support. Basal process narrow; basal sockets deep. Lateral margins thickened; neck pronounced. Cephalic tentacles, snout moderate-dark brown. Tentacles sometimes with central unpigmented streak. Foot lightly pigmented except for darkened anterior and posterior edges. Opercular lobe with darkened edges. Neck pale. Pallial roof, visceral coil dark brown-black. Ctenidial filaments, 15-20, medium height and width. Osphradium positioned centrally to slightly posterior to middle of ctenidial axis. Kidney with prominent bulge (up to 40%) into pallial cavity; opening thickened. Stomach with medium-sized triangular caecum. Testis, 1.5-2.0 whorls, overlapping stomach to edge of style sac. Prostate gland bean-like, strongly recurved, with large (25%) pallial section; pallial vas deferens with gentle proximal bend. Penis (Figure 49/) large; filament short, narrow; lobe short, broad. Dgl short, extending along right edge slightly onto base of filament; Dg3 a small tubercle (sometimes absent) borne on pronounced distal lobule. Terminal gland elongate, transverse, curved, largely ventral. Ventral gland small, sub-terminal, borne on low swelling. Filament darkly pigmented. Ovary, 1 whorl, overlapping posterior stomach chamber. Pallial albumen gland short, sometimes absent. Capsule gland shorter than albumen gland. Genital aperture a terminal broad pore without vestibule. Coiled oviduct of tight posterior oblique coil followed by (and overlapping) broad horizontal loop, positioned near middle of albumen gland. Oviduct and bursal duct join well posterior to pallial wall. Bursa copulatrix ovoid, elongate (up to 67%), broad (67%), with much of length (67%) posterior to albumen gland. Bursal duct medium length and width. Seminal receptacle finger-like, short, positioned alongside anteriormost bursa copulatrix and/or proximal bursal duct. TYPE LOCALITY.—Blue Spring, center SW1/4 sec. 27, T 24S, R 26E, Eddy County, New Mexico. DISTRIBUTION.—Pecos River drainage, southeastern New Mexico. REMARKS.—This species appears more closely related to northern congeners (P. hendersoni, P. idahoensis, P. robusta) than to local species. It differs in its smaller size, superficial position of Dgl, anterior position of seminal receptacle, and location of seminal receptacle along ventral edge of albumen gland. MATERIAL EXAMINED.—USNM 873131 (topotypes). Pyrgulopsis perturbata Hershler, 1989 Pyrgulopsis perturbata Hershler, 1989:189, figs. 26e-g, 33-36. DIAGNOSIS.—Shell ovate to low conical, medium to largesized, narrowly umbilicate. Penial filament short, lobe medium length. Penial ornament a small Dgl, transverse terminal gland, and ventral gland. DESCRIPTION.—Shell (Figure 23d) ovate to low conical; height, 2.7-4.0 mm; whorls, 4.25-5.0. Early protoconch very weakly punctate, otherwise near smooth. Teleoconch whorls slightly convex, sometimes shouldered; sculpture of very faint growth lines. Aperture broadly adnate to very slightly separated from body whorl. Inner lip complete, usually thick; columellar lip well reflected. Outer lip thick, slightly prosocline. Umbilicus rimate. Periostracum tan. Operculum (Figure 23
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A Review of the North American Fres
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S M I T H S O N I A N C O N T R I B
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Contents Page Introduction 1 Materi
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A Review of the North American Fres
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NUMBER 554 position of coiled ovidu
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NUMBER 554 field work and laborator
Page 13 and 14: NUMBER 554 FIGURE 2.—Morphology o
Page 15 and 16: NUMBER 554 Sr Ag Dsr FIGURE 4.—Di
Page 17 and 18: NUMBER 554 11 studied the anatomy o
Page 19 and 20: NUMBER 554 13 contrasted the genus
Page 21 and 22: NUMBER 554 15 FIGURE 7.—Western P
Page 23 and 24: NUMBER 554 17 Pyrgulopsis amargosae
Page 25 and 26: NUMBER 554 19 (in T 3S, R 22E, 25,0
Page 27 and 28: NUMBER 554 21 Pratt (1977) recorded
Page 29 and 30: NUMBER 554 23 DISTRIBUTION.—This
Page 31 and 32: NUMBER 554 25 nucleus slightly ecce
Page 33 and 34: NUMBER 554 27 FIGURE 11.—Western
Page 39 and 40: NUMBER 554 33 ornament an elongate,
Page 41 and 42: NUMBER 554 35 dium centered slightl
Page 43 and 44: NUMBER 554 FIGURE 15.—Western Pyr
Page 45 and 46: NUMBER 554 Pyrgulopsis glandulosa H
Page 47 and 48: NUMBER 554 41 visceral coil black.
Page 53 and 54: NUMBER 554 copulatrix. Seminal rece
Page 55 and 56: NUMBER 554 Pyrgulopsis merriami (Pi
Page 59 and 60: NUMBER 554 or lightly pigmented on
Page 61 and 62: NUMBER 554 weakly frilled. Attachme
Page 63: NUMBER 554 lake have not yielded li
Page 69 and 70: NUMBER 554 63 units; Dg3 small (som
Page 71 and 72: NUMBER 554 65 Pyrgulopsis simplex H
Page 75 and 76: NUMBER 554 69 DIAGNOSIS.—Shell ov
Page 77 and 78: NUMBER 554 71 filament, extending s
Page 79 and 80: NUMBER 554 FIGURE 28.—Eastern Pyr
Page 81 and 82: NUMBER 554 75 medium length, obliqu
Page 83 and 84: NUMBER 554 77 2e). Visceral coil li
Page 85 and 86: NUMBER 554 FIGURE 30.—Eastern Pyr
Page 87 and 88: NUMBER 554 ANSP 61606; paralectotyp
Page 89 and 90: NUMBER 554 83 and southeastern Ariz
Page 91 and 92: Appendix 2 Fossil Species Described
Page 93 and 94: NUMBER 554 87 Pyrgulopsis bryantwal
Page 95 and 96: NUMBER 554 89 FIGURE 32.—Central
Page 97 and 98: NUMBER 554 FIGURE 34.—Central rad
Page 101 and 102: NUMBER 554 FIGURE 38.—Central rad
Page 107 and 108: NUMBER 554 FIGURE 44.—Penes of we
Page 115 and 116:
NUMBER 554 FIGURE 52.—Penes of ea
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Abbott, R.T. 1948. A Potential Snai
Page 119 and 120:
NUMBER 554 Society of Washington, 1
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NUMBER 554 115 gyrus, Gabbia, Hydro
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A Review of the North American Freshwater Snail Genus Pyrgulopsis

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