CLASS GASTROPODA 
215 
the combination, when viewed under the microscope, giving to the surface 
a cloth-like texture. Suture strongly marked. Periphery of the last 
whorl inflated, strongly rounded. Base strongly rounded. Aperture 
narrowly ovate; posterior angle very obtuse; outer lip thin; inner lip 
short, very oblique, somewhat sinuous, reflected over the base and ap- 
pressed to it except at the extreme tip, which alone is free; a strong fold 
is present on the inner lip a little anterior to its insertion; parietal wall 
covered by a thin callus. Altitude, 7; diameter, 3.4 mm. (Bartsch.) 
Type in United States National Museum, No. 334492. Type locality, 
off San Juan Island, Puget Sound. 
Range. San Juan Islands, Gulf of Georgia. 
Odostomia farallonensis Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 221; PI. 27, fig. 7. 
Shell very elongate-ovate, deeply umbilicated, light-yellow. Nuclear 
whorls very deeply immersed. Post-nuclear whorls very slightly rounded 
in the middle between the sutures, more strongly so near the anterior end 
and toward the summit. Summit strongly narrowly tabulate. Periphery 
of the last whorl inflated. Base very strongly suddenly rounded, widely 
and deeply umbilicated. Entire surface marked by numerous fine, closely- 
spaced, spiral striations. Aperture broadly ovate, posterior angle obtuse, 
outer lip thin; columella very slender, strongly curved, revolute, provided 
with a deep fold a little below its insertion; parietal wall glazed with a 
thin callus. Length, 5.5; diameter, 2.7 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 168827. Type locality, 
United States Bureau of Fisheries Station 3180, off the harallon Islands, 
California. 
Range. Known only from type locality. 
Odostomia grippiana Bartsch, 1912 
Proceedings of the United States National Museum, 42:287; PI. 38, fig. 11. 
Shell large, umbilicated, yellowish-white. Nuclear whorls decollated. 
Post-nuclear whorls decidedly, slopingly, tabulately shouldered at the 
summit, otherwise moderately rounded; marked by fine incremental lines 
and numerous, equal and equally spaced, slender, wavy, spiral threads, 
of which 6 occur upon the shoulder, and about 40 between the shoulder 
and the suture. Periphery and the moderately long base of the last whorl 
well-rounded, marked like the spire. Aperture moderately long, stout, 
curved, somewhat reflected, provided with a strong fold a little anterior 
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