CLASS GASTROPODA 
207 
prolonged, well-rounded, its entire surface marked by incised spirals like 
the spaces between the sutures. In addition to the spiral markings the 
entire surface shows fine incremental lines. Aperture elongate-oval, effuse 
at the junction of the outer lip and the columella; posterior angle obtuse; 
columella stout, curved, and decidedly reflected over the re-enforced base, 
provided with a strong oblique fold opposite the obsolete umbilical chink; 
parietal wall covered with a thin callus. Length, 5.3; diameter, 2.6 mm. 
(Dali and Bartsch.) 
Type in United States National Museum, No. 204010. Type locality, 
Bear Bay, Peril Straits, BaranofT Island, Alaska. 
Range. Bear Bay, Peril Straits, Alaska, to Barkley Sound, British 
Columbia. 
Odostomia tacomaensis Dali and Bartsch, 1907 
Plate 66, fig. 10 
Proceedings of the United States National Museum, 33:526; PI. 47, fig. 10. 
Shell ovate, yellowish. Nuclear whorls small, deeply immersed in the 
first of the succeeding turns. Post-nuclear whorls well-rounded, faintly 
roundly shouldered at the extreme summits. Periphery of the last whorl 
rounded. Base inflated, well-rounded, somewhat attenuated anteriorly. 
Surface covered by numerous, equal and equally closely spaced, slender, 
wavy, spiral striations of which there are about 40 between the summit 
and the periphery of the last whorl. Base marked like the space posterior 
to it. In addition to the spiral sculpture the entire surface of the shell 
is crossed by numerous fine lines of growth. Aperture moderately large, 
oval, well-rounded anteriorly; posterior angle acute; outer lip thin; colu¬ 
mella curved, slightly reflected, re-enforced, except at its extreme anterior 
end, by the attenuated base and provided with a strongly oblique fold at 
its insertion. Length, 4.3; diameter, 2.5 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 159267. Fype locality, 
Tacoma, Washington. 
Range. Known only from type locality. 
Odostomia tenuisculpta Carpenter, 1864 
Plate 63, fig. 2; Plate 66, fig. 6 
Supplementary Report, British Association for the Advancement of Science, 659. 
Bulletin 68, United States National Museum; PI. 23, fig. 2. 
O. testa ovoidea, subelevata, albida, tenui, diaphana; anfr. nucl. sub- 
verticaliter immersis, angustis; norm, iii., parum tumidis, subturis im- 
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