A Review of the North American Freshwater Snail Genus Pyrgulopsis

NUMBER 554
Pyrgulopsis glandulosa Hershler, 1988
Pyrgulopsis glandulosus Hershler in Hershler and Landye, 1988:8, figs. 3a-c,
4-9,10a,b.—USDI, 1991b:58821.
DIAGNOSIS.—Shell broadly to low-conical, medium-sized,
umbilicate. Penial filament and lobe short. Penial ornament an
elongate Dgl, elongate Dg2, Dg3 borne on weak swelling;
elongate, transverse, curved terminal gland and two ventral
glands. Dorsal glands sometimes fused.
DESCRIPTION.—Shell (Figure 15g) broad to low-conical;
height, 2.0-2.8 mm; whorls, 3.5-4.0. Protoconch weakly
punctate. Teleoconch whorls moderately convex, shouldered;
sculpture of strong growth lines. Aperture narrowly adnate or
(more commonly) separated from body whorl. Inner lip
complete, thickened; columellar lip slightly reflected. Outer lip
orthocline to slightly prosocline. Umbilicus narrowly rimate to
shallowly perforate. Periostracum tan.
Operculum (Figure \5h,i) ovate, amber, nucleus slightly
eccentric; dorsal surface smooth. Attachment scar margin
broadly thickened along inner edge (sometimes all around),
thinner to faint along outer edge; callus pronounced.
Central radular tooth (Figure 35/) with slightly indented
dorsal edge; lateral cusps, 5; central cusp rounded, slightly
broader and longer than laterals; basal cusps, 1, medium-sized,
curved, with weak dorsal support. Basal process narrow; basal
sockets deep. Lateral margins thickened; neck weak-moderate.
Cephalic tentacles pale, or with moderate internal gray
pigment patch just distal to eyespots. Snout pale, rarely light
brown. Foot pale. Opercular lobe pale, or with moderate
gray-black internal pigment on sides and along inner edge.
Neck pale or with central patch of internal black granules.
Pallial roof, visceral coil black.
Ctenidial filaments, 21, tall, medium width. Osphradium
centered slightly posterior to middle of ctenidial axis. Kidney
opening slightly thickened. Stomach caecum small.
Testis, 1 whorl, overlapping posterior stomach chamber.
Prostate gland a fat bean shape, with large (33%) pallial
section; pallial vas deferens strongly kinked proximally. Penis
(Figure 46>) large, extending well beyond mantle edge;
filament less than half length of base, narrow; lobe short,
distally tapered. Dgl elongate, usually oblique, extending from
right edge (slightly overlapping proximal filament) to midpenis
(but sometimes with sharp posterior bend), posterior
portion borne on low swelling; Dg2 elongate, often fused with
Dg3; Dg3 borne on weak swelling. Dorsal penis sometimes
with several small glandular dots distally. Terminal gland large,
transverse, slightly curved, borne on distal edge of lobe, usually
on ventral surface. Ventral glands, usually 2, large, stalked,
positioned from center to distal edge; proximal gland sometimes
absent or broken into several small units.
Ovary, 0.5 whorl, overlapping posterior stomach chamber.
Pallial albumen gland short Capsule gland shorter than
albumen gland. Genital aperture a subterminal slit, slightly
raised and thickened, with short vestibule. Coiled oviduct a
broad horizontal loop well posterior to pallial wall. Oviduct and
bursal duct join well behind pallial wall. Bursa copulatrix
ovoid, short, medium width, largely (67%) posterior to
albumen gland. Bursal duct very narrow, shallowly embedded
in albumen gland, about as long as bursa copulatrix. Seminal
receptacle pouch-like, medium length, overlapping anterior
bursa copulatrix, extending to posterior edge of albumen gland.
TYPE LOCALITY.—Nelson Place Spring, Yavapai County,
Arizona (T UN, R 5E, sec. 16). Holotype, USNM 859047;
paratypes, USNM 859048.
DISTRIBUTION.—Verde River drainage, central Arizona.
REMARKS.—Distinguished from similar P. montezumensis
(also from Verde River drainage) by larger penial lobe,
presence of Dg3, frequent fusion of dorsal glands, and simple
oviduct coil.
MATERIAL EXAMINED.—USNM 847205 (topotypes).
Pyrgulopsis hendersoni (Pilsbry, 1933)
Paludestrina sp.—Henderson, 1929:167.
Amnkola hendersoni Pilsbry, 1933:10, pi. 2: figs. 2, 9, 10.—Henderson,
1936b:276.
Fontelicella (Natricola) hendersoni.—Gregg and Taylor. 1965:109.—Taylor
and Smith, 1981:350-351.—Burch, 1982:26. fig. 240.
Fontelicella hendersoni.—Taylor, 1975:94.—Turgeon et al., 1988:61.
Pyrgulopsis hendersoni.—Hershler and Thompson, 1987:29.
DIAGNOSIS.—Shell ovate to low-conical, large, weakly
umbilicate. Penial filament short, lobe medium length, broad.
Penial ornament an elongate Dgl, short Dg2, Dg3 borne on
lobule, elongate, transverse terminal gland, and ventral gland.
Dorsal glands sometimes fused.
DESCRIPTION.—Shell (Figure 160,6) ovate- to low-conical;
height, 4.0-6.5 mm; whorls, 4.5-5.5 whorls. Early protoconch
weakly punctate, otherwise nearly smooth. Teleoconch whorls
moderately convex, rarely slightly shouldered; sculpture of
weak growth lines and faint spiral striae. Aperture ovate, large,
broadly adnate to slightly separated from body whorl. Inner lip
complete, thin to moderately thick; columellar lip occasionally
slightly reflected. Outer lip thin to moderately thick, orthocline
to slightly prosocline. Umbilicus narrowly rimate to near
absent Periostracum olive-tan.
Operculum (Figure \6c,d) broadly ovate, amber (nuclear
region and adjacent inner edge near red); nucleus slightly
eccentric; dorsal surface smooth. Attachment scar margin
broadly thickened all around, distinctly raised between nucleus
and inner edge; callus moderate.
Central radular tooth (Figure 36a) with moderately indented
dorsal edge; tooth face square; lateral cusps, 3-6; central cusp
rounded, broader and slightly longer than laterals; basal cusps,
1, short, curved, with strong dorsal support Basal process
broad; basal sockets shallow. Lateral margins thickened; neck
very weak.
Snout dark purple; pigment light to dark on foot, neck.
Cephalic tentacles usually dark at least proximally. Opercular
lobe with dark internal pigment in anterior half. Pallial roof,
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