A Review of the North American Freshwater Snail Genus Pyrgulopsis

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26 almost to filament tip, sometimes fused posteriorly with Dgl. Dgl crossing entirety of penis width near mid-point, sometimes extending anteriorly along right edge, occasionally fusing with penial gland; Dg2 elongate, positioned along left distal edge, often uniting with Dgl; Dg3 borne on weak lobule along right edge of lobe, sometimes fragmented into several small glands. Dorsal penis also bearing 1-5 elongate, longitudinal-oblique glands distally. Terminal gland elongate, curved, transverse, borne along distal edge (largely ventral surface) of lobe. Ventral gland positioned near base of lobe, borne on low swelling, flanked by smaller, similarly stalked gland(s) on either or both sides. Proximal filament and adjacent area of penis usually darkly pigmented internally. Female genitalia shown in Figure 5b. Ovary, 1 whorl, pressed against edge of or slightly overlapping posterior stomach. Pallial albumen gland short (16%). Capsule gland slightly shorter than albumen gland. Genital aperture a terminal slit, vestibule well developed. Coiled oviduct a broad horizontal loop (sometimes preceeded by slight kink) positioned well behind pallial wall, overlapping much of posterior albumen gland. Oviduct and bursal duct join anterior to coil just behind pallial wall. Bursa copulatrix pyriform, posterior end angled, long, (50%-75%), as broad as albumen gland, with almost entire length (about 90%) posterior to albumen gland. Bursal duct narrow, although sometimes with very wide proximal section, slightly shorter than bursa copulatrix. Seminal receptacle pouch-like, short, overlapping anteriormost bursa copulatrix, extending to posterior edge of albumen gland. TYPE LOCALITY.—Campo Creek, San Diego County, California, 0.6 mi. (1.0 km) east of Mountain Empire Dam (Wl/2 SW1/4 sec. 19, T 18S, R 5E). Holotype, UMMZ 220000. DISTRIBUTION.—Pacific coastal and interior drainage, southem California and northern Baja California (Gregg and Taylor, 1965; Taylor, 1981). Record(s) for Baja California require confirmation. REMARKS.—Among the group of species having a full complement of glands on the penis (i.e., penial gland, Dgl-3, terminal gland, ventral gland), only P. californiensis and P. wongi have multiple ventral glands and a short seminal receptacle. Pyrgulopsis californiensis differs by its elongate shell, albumen gland with pallial portion, shorter and more posteriorly positioned bursa copulatrix, and longer bursal duct. MATERIAL EXAMINED.—SBMNH uncat. (topotypes). Pyrgulopsis carinifera (Pilsbry, 1935a), new combination Fluminicola avernalis carinifera Pilsbry, 1935a:93, fig. 3.—Morrison, 1940:124.—Gregg, 1941:117. "Fluminicola" carinifera.—Baker, 1964:171.—Taylor, 1975:53. DIAGNOSIS.—Shell trochoid, basally carinate, medium to large-sized, anomphalous or very weakly umbilicate. Penial SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY lobe and filament medium length; lobe distally bifurcate. Penial ornament a fragmented terminal gland. DESCRIPTION.—Shell (Figure 1 la) trochoid; height, 3.8-5.0 mm; whorls, 4-5. Protoconch very weakly punctate. Teleoconch whorls slightly convex, sometimes shouldered. Periphery of body whorl varying from slightly angled to strongly keeled, with keel weakening near aperture; teleoconch sculpture otherwise only of strong growth lines. Aperture ovate, angled above, adnate to body whorl. Inner lip usually complete, columellar lip highly thickened, parietal lip less so. Outer lip medium thickness, strongly prosocline. Umbilicus absent or small, narrowly rimate. Periostracum light brown, very thin. Operculum (Figure \\b,c) broadly ovate, light amber; nucleus slightly eccentric; dorsal surface frilled. Attachment scar margin a faint trace, sometimes only evident between nucleus and inner edge; callus very weak-absent. Central radular tooth (Figure 33/) with moderately indented dorsal edge; lateral cusps, 4-5; central cusp pointed, slightly broader and longer than laterals; basal cusps, 1, very short, with weak dorsal support. Basal process medium width; basal sockets deep. Lateral margins thickened; neck very weak. Cephalic tentacles usually light brown, with pigment often present only distally. Snout and neck pale to light brown, with black internal patch present posterior to tentacle bases. Foot generally pale, but often dark along anterior and posterior edges; opercular lobe often with pronounced brown streaks on sides. Pallial roof, visceral coil light-moderate brown, with pigment especially dark over gonads. Ctenidial filaments, 35, broad, tall. Osphradium positioned posterior to center of ctenidial axis. Stomach caecum very small, triangular. Testis, 0.5 whorl, overlapping posterior stomach. Prostate gland reniform, short, thin-walled, without pallial section; pallial vas deferens without proximal kink. Penis (Figure 44/) medium-sized, scarcely extending beyond mantle collar, base elongate, narrowing distally; filament medium length, strongly tapering, with pointed tip; lobe medium length, broad, bifurcating distally. Terminal gland fragmented into two elongate, transverse units borne along distal edges of bifurcated lobe. Filament darkly pigmented internally. Ovary, 1 whorl, overlapping posterior stomach. Pallial oviduct small, terminating well posterior to edge of pallial cavity. Albumen gland without a pallial section. Capsule gland as long as albumen gland (posterior section very small and behind pallial wall), highly thickened. Genital aperture a terminal slit; vestibule present Coiled oviduct a small horizontal loop just behind pallial cavity wall. Oviduct and bursal duct join just behind pallial wall. Bursa copulatrix ovoid, medium length, narrow (33%), positioned along ventral edge of posterior albumen gland with very small or no portion posterior to gland. Bursal duct broad, about as long as bursa copulatrix. Seminal receptacle finger-like, short, overlapping proximal
NUMBER 554 27 FIGURE 11.—Western Pyrgulopsis: a-c, P. carinifera (a. shell. USNM 874099, 2.8 mm; bjc, opercula, USNM 874097, bars = 0.5 mm, 0.6 mm); d-f. P. cedrosensis, ANSP 141408 (d, shell, 1.8 mm; e,f. opercula, bar = 0.25 mm). bursal duct, positioned near ventral edge of albumen gland. TYPE LOCALITY.—As for P. avernalis, this species was described from fossil shells attributed to Colorado Desert, but the type locality almost certainly is from Moapa Valley, southern Nevada. Lectotype (Baker, 1964:171), ANSP 164091; paralectotypes, ANSP 375736. DISTRIBUTION.—Springs in Moapa Valley, southern Nevada, Colorado River drainage. REMARKS.—Among the various species sharing a penis solely ornamented by a terminal gland, P. carinifera is differentiated by features including a large, strongly bifurcate penial lobe, and narrow bursa copulatrix entirely overlapped by the albumen gland. The affinities of this snail possibly lie with two species from Ash Meadows that also have a globose- trochoid shell, sub-central operculum nucleus, and albumen gland without pallial section. MATERIAL EXAMINED.—USNM 874001, unnamed spring, Moapa Valley, Clark County, Nevada (T 14S, R 65E, sec. 16). Pyrgulopsis cedrosensis (PUsbry, 1927), new combination Paludestrina cedrosensis Pilsbry, 1927:188, fig. 3. Fontelicella (Fontelicella) cedrosensis.—Gregg and Taylor, 1965:108. Fontelicella cedrosensis.—Taylor, 1975:55. DIAGNOSIS.—Shell ovate-conic, small to medium-sized. Penial lobe, filament medium length. Penial ornament unknown.
Page 1 and 2: A Review of the North American Fres
Page 3 and 4: S M I T H S O N I A N C O N T R I B
Page 5 and 6: Contents Page Introduction 1 Materi
Page 7 and 8: A Review of the North American Fres
Page 9 and 10: NUMBER 554 position of coiled ovidu
Page 11 and 12: 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: NUMBER 554 25 nucleus slightly ecce
Page 35 and 36: NUMBER 554 29 FIGURE 12.—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 and 64: NUMBER 554 lake have not yielded li
Page 65 and 66: NUMBER 554 59 REMARKS.—The small
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 99 and 100:
Page 101 and 102:
NUMBER 554 FIGURE 38.—Central rad
Page 103 and 104:
Page 105 and 106:
Page 107 and 108:
NUMBER 554 FIGURE 44.—Penes of we
Page 109 and 110:
Page 111 and 112:
Page 113 and 114:
Page 115 and 116:
NUMBER 554 FIGURE 52.—Penes of ea
Page 117 and 118:
Abbott, R.T. 1948. A Potential Snai
Page 119 and 120:
NUMBER 554 Society of Washington, 1
Page 121:
NUMBER 554 115 gyrus, Gabbia, Hydro
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A Review of the North American Freshwater Snail Genus Pyrgulopsis

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