A Review of the North American Freshwater Snail Genus Pyrgulopsis

46
of filament Terminal gland elongate, straight, transverse
(sometimes fragmented into 2-3 units), positioned along distal
edge of lobe. Ventral gland usually prominent (sometimes
weak or absent), stalked, borne on ventral surface of lobe
(glandular dot distal to above also sometimes present).
Filament with moderately dark internal pigment.
Ovary, 1 whorl, overlapping posterior stomach. Albumen
gland with short pallial section. Capsule gland shorter than
albumen gland. Genital aperture a sub-terminal slit with
vestibule. Coiled oviduct of two overlapping horizontal loops
(proximal loop smaller) positioned slightly behind pallial wall.
Oviduct and bursal duct join just behind pallial wall. Bursa
copulatrix ovoid, medium length and width, with much of
length (50%-70%) posterior to albumen gland. Bursal duct
slender to wide, shallowly embedded in albumen gland,
medium length. Seminal receptacle pouch-like, short, slightly
overlapping anterior bursa copulatrix or overlapping (or lateral
to) proximal bursal duct, usually positioned near ventral edge
of albumen gland.
TYPE LOCALITY.—Pyrgulopsis kolobensis: Toquerville Springs,
sec. 35, T 40S, R 13W, Washington County, Utah.
Holotype, LACM 2216. Pyrgulopsis pine tor um: Spring tributary
to Leeds Creek, 2,400 ft W, 2,300 ft N, sec. 16, T 40S, R
14W, Washington County, Utah. Holotype, LACM 2217.
DISTRIBUTION.—Upper Virgin River drainage, southwestern
Utah.
REMARKS.—Study of numerous lots of material from the
upper Virgin River drainage revealed extensive variation in
features used to separate kolobensis and pinetorum by Taylor
(1987), including the presence/absence of a ventral gland on the
penis, thus suggesting that a single species is involved.
Amongst the group of species whose penes are ornamented
solely by penial, terminal, and ventral glands, this snail is
distinguished by its ovate-conic shell and weak ventral
operculum callus.
MATERIAL EXAMINED.—USNM 847249 (topotypes,
kolobensis).
Pyrgulopsis longinqua (Gould, 1855)
Amnicola longinqua Gould, 1855:130; 1856:333, pi. XI: figs. 10,11.—Binney,
1865:87, fig. 173.—Tryon, 1870:36, pi. 17: fig. 5.—Baily and Baily,
1951:51. pi. 4: fig. 7.
Paludestrina longinqua.—Pilsbry, 1899:122 [in part].—Steams, 1901:284, fig.
2.—Walker, 1918:138.
Pelidostrema [sic] longigua [sic].—Jaeger, 1965:65.
Fontelicella s.s. longinqua.—Gregg and Taylor, 1965:108.—Taylor, 1975:114.
Pyrgulopsis longinqua.—Hershler and Thompson, 1987:29.
DIAGNOSIS.—Shell ovate to narrowly-conic, medium-sized,
weakly umbilicate. Penial filament and lobe medium length.
Penial ornament an elongate penial gland, transverse Dgl, Dg2,
Dg3 borne on swelling; elongate, transverse terminal gland,
and ventral gland. Dorsal glands sometimes fused.
SMITHSONIAN CONTRIBUTIONS TO ZOOLOGY
DESCRIPTION.—Shell (Figure Wd,e) ovate-narrow conic;
height, 2.5-3.8 mm; whorls, 4.5-5.0. Protoconch near smooth
except for faint adapical spiral lines on later portion.
Teleoconch whorls moderately convex, slightly shouldered;
sculpture of strong growth lines. Aperture ovate, small, broadly
adnate to very slightly separated from body whorl. Inner lip
complete, thin to thick; columellar lip slightly reflected. Outer
lip thin to thick, orthocline to slightly prosocline. Umbilicus
absent to narrowly rimate or very shallowly perforate.
Periostracum light tan.
Operculum (Figure \Sf,g) narrow-broadly ovate, light
amber, nucleus slightly eccentric; dorsal surface frilled.
Attachment scar margin moderately thickened all around;
callus moderate.
Central radular tooth (Figure 36/) with moderately indented
dorsal edge; lateral cusps, 5; central cusp pointed, slightly
broader and considerably longer than laterals; basal cusps, 1,
short, with moderate dorsal support. Basal process moderately
broad; basal sockets deep. Lateral margins slightly thickened;
neck pronounced.
Head-foot generally pale. Snout sometimes light gray.
Opercular lobe sometimes with moderate internal gray-black
patch along anterior edge. Neck sometimes with internal black
pigment. Pallial roof, visceral coil usually pale or weakly
pigmented (rarely dark).
Ctenidial filaments, 20, medium height and width. Osphradium
centered slightly posterior to middle of ctenidium.
Kidney opening white. Stomach with prominent caecum.
Testis, 1 whorl, extending to posterior edge of stomach.
Prostate gland an elongate bean-shape, with short pallial
section; pallial vas deferens with proximal kink. Penis (Figure
47e) large, extending well beyond mantle edge; base squarerectangular,
filament medium length, broad; lobe equal to or
slightly longer than filament, expanded distally. Penial gland
filling most of filament, sometimes fused with Dgl. Dgl
crossing at least half of penis width near mid-length; Dg2
short-elongate, sometimes fused with Dgl and/or Dg3; Dg3
borne on moderately raised swelling. Dorsal penis also with
1-3 additional small glands near distal edge, sometimes fused
with Dg2 or Dg3. Terminal gland elongate, transverse, curved,
borne along distal edge, largely on ventral surface. Ventral
gland small, stalked, positioned near mid-length. Filament pale
to with dark internal pigment
Ovary, 0.5 whorl, pressed against posterior edge of stomach.
Pallial albumen gland short. Capsule gland as long as albumen
gland. Genital aperture a broad terminal slit with vestibule.
Coiled oviduct a broad, open horizontal loop (sometimes
proceeded by weak horizontal kink) filling much of albumen
gland length. Oviduct and bursal duct join anterior to oviduct
coil just behind pallial wall. Bursa copulatrix ovoid, medium
length and width, with most of length (77%) posterior to
albumen gland. Bursal duct slender, about as long as bursa