CLASS GASTROPODA 
181 
mella curved; re-enforced by the attentuated base and provided with a 
strong fold and its insertion; parietal wall covered by a thin callus. Length, 
3.2; diameter, 1.8 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 196299. Type locality, 
Port Harford, California. 
Range. Known only from type locality. 
Odostomia hypocurta Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 190; PL 21, fig. 8. 
Shell very elongate-ovate, bluish-white. (Nuclear whorls decollated.) 
Post-nuclear whorls well-rounded, marked by five, broad, strong, deeply 
incised, spiral grooves, that divide the space between the sutures into 
raised, flattened keels, which are successively a little wider from the 
summit to the periphery. Periphery of the last whorl marked by a groove 
similar to those above. Base rather short, moderately rounded, marked 
by five subequal and subequally spaced, spiral grooves, which are a little 
weaker than those on the spire. The entire surface of the shell is marked 
by slender lines of growth, and the raised spaces between the spiral grooves 
are finely spirally striated. Suture strongly impressed. Aperture? (outer 
lip fractured) ; columella strong, curved, revolute, its posterior two-thirds 
re-enforced by the base; columella fold not visible in the aperture. Oper¬ 
culum paucispiral. Length, 4.3; diameter, 2.2 mm. (Dali and Bartsch.) 
Type in United States National Museum; No. 168660. Type locality, 
United States Bureau of Fisheries Station 3306, off Bristol Bay, Bering 
Sea, Alaska. 
Range. Known only from type locality. 
Odostomia pharcida Dali and Bartsch, 1907 
Plate 57, fig. 8 
Proceedings of the United States National Museum, 33:520; PL 46, fig. 8. 
Shell small, subcylindric, yellowish-white. Nuclear whorls deeply 
immersed, a portion of the last and the penultimate only appear when 
viewed from the side; this gives the shell a truncated appearance. Post- 
nuclear whorls moderately well-rounded, rather wide between the sutures, 
and somewhat shouldered at the summits; ornamented by strong, low, 
rounded spiral cords, which are separated by moderately deep, narrow, 
depressed channels. Six of these cords occur upon the first, 7 upon the 
second to the penultimate whorl, between the sutures; the posterior cord 
is a little broader and less elevated than the rest, while some of those on 
the penultimate turn show a tendency to divide, that is, a faint spiral line 
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