226 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
shell. Operculum is very thin, circular, of a delicate horn-color, with 
central nucleus of about 7 whorls defined by a fine spiral line. (Bush.) 
Type. Leptogyra verrilli Bush. 
Distribution. Alaska, Cooks Inlet, circumboreal. 
Leptogyra alaskana Bartsch, 1910 
Plate 104, figs. 4, 5, 6 
Nautilus, 23, No. 11, 136; PI. 11, figs. 4-6. 
Shell minute, depressed helicoid. Nuclear whorls one and one-half, 
light yellow horn color, marked by faint incremental lines. A single post- 
nuclear turn follows, which is bluish-white, rather broad, and gently, 
almost evenly, curved from the well-impressed suture to the periphery. 
This whorl is marked by about twelve fine, incised, spiral lines between 
the suture and the periphery, which are stronger toward the periphery 
than at the suture. Periphery of the last whorl rounded. Base broadly 
and deeply umbilicated, strongly arched, with a slender cord at the 
junction of the basal and parietal wall, surface of the base marked by 
incised lines which are equal in strength and number to those occurring 
upon the upper surface. Wall of the umbilicus almost flat, marked by 
faint spiral lines. Aperture very large, subcircular, posterior angle obtuse; 
outer lip thin; columella curved, somewhat expanded and thickened bas- 
ally; parietal wall covered with a thin callus. Operculum thin, horny. 
.... the type measures: greater diameter, 0.85; lesser diameter, 0.7; 
altitude, 0.4 mm. (Bartsch.) 
Type in United States National Museum, No. 208433. Type locality, 
Port Graham, Alaska. 
Range. Port Graham, Cooks Inlet, Alaska. 
Genus TEINOSTOMA A. Adams, 1854 
Shell orbicular, depressed, subspiral, polished or spirally striated, last 
whorl rounded, or angulated at the periphery; umbilical region covered 
with a large, flat callosity; aperture transverse; inner lip smooth, callous; 
outer lip thin, simple, not margined or reflected. (Tryon, Structural and 
Systematic Conchology.) 
Type. T. politum A. Adams. 
Distribution. Philippines, Japan, Mazatlan. 
Teinostoma salvania Dali, 1919 
Proceedings of the United States Natioml Museum, 56:369. 
Shell small, translucent white, moderately depressed, smooth, of about 
three and a half whorls, with a minute inflated nucleus; the only sculpture 
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