212 
MARINE SHELLS OF WEST COAST OF NORTH AMERICA 
what revolute, provided with a strong oblique fold a little anterior to its 
insertion; parietal wall glazed with a thick callus. Length, 6.5; diameter, 
2.4 mm. (Dali and Bartsch.) 
Type in Geological Survey Museum, Ottawa, and United States Na¬ 
tional Museum, No. 211542. Type locality, ship channel, Barkley Sound, 
Vancouver Island, British Columbia. 
Range. Known only from type locality. 
Subgenus Amaura Moller, 1842 
Odostomia arctica Dali and Bartsch, 1909 
Plate 64, fig. 5 
Bulletin 68, United States National Museum, 224; PI. 28, fig. 5. 
Shell large, elongate-ovate, straw-yellow. (Nuclear whorls decollated.) 
Post-nuclear turns well-rounded, with subtabulate summits, marked by 
lines of growth and numerous, fine, closely-placed, wavy, spiral striation. 
Periphery well-rounded. Suture well-impressed. Base rather elongated, 
marked like the space between the sutures. Aperture pear-shaped, rather 
narrow posteriorly, and somewhat effuse anteriorly, posterior angle ren¬ 
dered obtuse by the tabulation; outer lip thin; columella short, curved, 
slightly reflected, re-enforced by the attenuated base and provided with a 
weak fold at its insertion; parietal wall covered by a thin translucent 
callus. Length, 12.4; diameter, 6.5 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 168766. Type locality, 
Hagemeister Island, Bering Sea. 
Range. Seahorse Islands, Arctic Ocean, to Bristol Bay, Bering Sea. 
Odostomia avellana Carpenter, 1865 
Plate 64, fig. 3 
Annals and Magazine of Natural History, series 3, 15 :30. Bulletin 68, United States 
National Museum; PI. 27, fig. 3. 
O. testa O. nuciformi indole simili, sed spira valde prolongata. Long., 
.32; long, spir., .16; lat., .16 poll. (Carpenter.) 
Shell large, elongate-ovate, yellowish to milk-white. Nuclear whorls 
deeply vertically immersed; only part of the last volution is visible when 
viewed from above, their axis evidently being at a right angle to the axis 
of the later whorls. Post-nuclear whorls increasing rapidly in size, early 
ones well-rounded, later ones less so, their summits being closely appressed 
to the preceding whorl. Suture well-impressed, simple. Periphery and 
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