A Review of the North American Freshwater Snail Genus Pyrgulopsis

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caecum prominent, broadly triangular.
Testis, 2 whorls, overlapping anterior stomach chamber to
edge of style sac. Prostate gland with short pallial section;
pal Hal vas deferens with weak proximal undulation. Penis
(Figure 50a) large; filament short, narrow; lobe slightly longer
than filament, broad, slightly oblique. Dgl small, positioned
near base of filament Terminal gland usually transverse, borne
along ventral surface. Ventral gland (rarely split into two)
borne on sub-terminal swelling. Filament dark.
Ovary, 1 whorl, overlapping posterior stomach chamber.
Pallial albumen gland short Albumen gland as long as capsule
gland. Genital aperture a broad terminal slit with short
vestibule. Coiled oviduct a short horizontal twist followed by
broad horizontal loop, often kinked near mid-length, positioned
slightly behind pallial wall. Oviduct and bursal duct join just
behind pallial wall. Bursa copulatrix ovoid, short (32%-40%),
narrow (33%), with 43%-80% of length posterior to gland.
Bursal duct medium width, shallowly embedded in albumen
gland, about as long as bursa copulatrix. Seminal receptacle
pouch-like, narrow, folded, short, overlapping (or lateral to)
proximal bursal duct
TYPE LOCALITY.—Southern of two "Northwest Springs,"
Fish Slough, Mono County, California (T 5S, R 32E, SE1/4
sec. 13). Holotype, USNM 860407; paratypes, USNM 853546.
DISTRIBUTION.—Headsprings in Fish Slough, Owens River
drainage.
MATERIAL EXAMINED.—USNM 857990 (topotypes);
USNM 857991, northern of two "Northwest Springs" (data as
above).
Pyrgulopsis pilsbryana (Baily and Baily, 1952)
Paludestrina longinqua.—Pilsbry, 1899:122 [in part].—Steams, 1901:285 [in
part].—Henderson and Daniels, 1917:58, 59.—Henderson, 1924:190;
1931:110.—Chamberlain and Jones, 1929:177 [in part].
Amnicola pilsbryi Baily and Baily, 1951:50, pi. 4: fig. 3 [not Walker,
1906].—Baker, 1964:175.
Pyrgulopsis pilsbryi.—Hershler and Thompson, 1987:30.
Amnicola pilsbryana Baily and Baily, 1952:144 [new name for above].—
Taylor, 1965:599.
Fontelicella pilsbryana.—Gregg and Taylor, 1965:108.—Taylor, 1975:152 —
Burch, 1982:26.—Turgeon et al., 1988:61.
DIAGNOSIS.—Shell conical, medium to large-sized, umbilicate.
Penial filament medium length, lobe short Penial
ornament a small penial gland; small, weakly raised Dg3; and
horizontal terminal gland.
DESCRIPTION.—Shell (Figure 23g) conical; height 2.7-5.0
mm; whorls, 4-5. Protoconch near smooth except for a few
adapical spiral lines on later portion. Teleoconch whorls highly
convex, strongly shouldered; sculpture of variably expressed
growth lines. Aperture narrowly adnate to body whorl, rarely
separated. Inner lip complete, only very slightly thickened;
columellar lip slightly reflected. Outer lip slightly prosocline.
Umbilicus shallowly perforate. Periostracum brown.
Operculum (Figure 23/»,/) ovate, amber, considerably darker
in nuclear area; nucleus slightly eccentric; dorsal surface
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
frilled. Attachment scar margin moderately thickened along
inner edge (to nucleus), otherwise a faint trace; callus weak.
Central radular tooth (Figure 39a) with moderately indented
dorsal edge; lateral cusps, 4; central cusp pointed, considerably
broader, longer than laterals; basal cusps, 1, medium-sized,
with weak-moderate dorsal support. Basal process narrow;
basal sockets deep. Lateral margins thickened; neck weak.
Cephalic tentacles, snout, foot, neck light to dark browngray.
Opercular lobe with dark internal pigment along sides.
Neck sometimes with scattered dark internal granules. Pallial
roof, visceral coil near uniform black. Entire animal sometimes
black.
Ctenidial filaments, 23, medium height and width. Osphradium
centrally positioned along ctenidial axis. Kidney opening
slightly thickened. Stomach caecum prominent
Testis, 1.5-2.0 whorls, overlapping stomach to posterior
edge of style sac. Prostate gland with short pallial section;
pallial vas deferens gently undulating proximally. Penis
(Figure 50b) large; filament medium length, narrow; lobe short
tapered distally. Penial gland weak, covering only base of
filament, sometimes extending slightly onto penis. Dg3 small,
superficial or (less commonly) very weakly raised, near outer
edge close to base of filament. Terminal gland horizontal
(rarely split into two), borne distally, largely on ventral surface.
Filament dark.
Ovary, 0.75-1.0 whorl, overlapping posterior stomach
chamber. Pallial albumen gland short-long (15%-25%).
Capsule gland as long as albumen gland. Genital aperture a
subterminal pore without or with very short vestibule. Coiled
oviduct a slight posterior oblique twist followed by broad
horizontal loop slightly behind pallial wall. Oviduct and bursa
duct join just behind pallial wall. Bursa copulatrix ovoid,
medium length, broad (70%), with about 67% of length
posterior to gland. Bursa duct narrow, shallowly embedded in
albumen gland, about as long as bursa copulatrix. Seminal
receptacle sac-like, narrow, short, overlapping proximal bursal
duct
TYPE LOCALITY.—Lifton, Ideal Beach, Bear Lake, Idaho.
Holotype, ANSP 187691; paratypes, ANSP 368401.
DISTRIBUTION.—Bear Lake basin, southeastern Idahonortheastern
Utah.
REMARKS.—Distinguished from similar P. trivialis by weak
ventral operculum attachment scar, absence of Dg2 and ventral
gland, and anterior position of seminal receptacle.
MATERIAL EXAMINED.—USNM 858279, unnamed spring,
about 0.6 km northwest of Lakota, Rich County, Utah (T 14N,
R 5E, NE1/4 sec. 5).
Pyrgulopsis pisteri Hershler and Sada, 1987
Pyrgulopsis pisteri Hershler and Sada, 1987:804, figs. 29b,e, 33c 34a~e. 35.
36.—USDL 1991b:58821
DIAGNOSIS.—Shell globose to broadly conical, small to
medium-sized, umbilicate. Penial filament medium length,
lobe very weak or absent Penial ornament a large, superficial