CLASS GASTROPODA 
197 
Odostomia killisnooensis Dali and Bartsch, 1909 
Bulletin 68, United States National Museum, 195; PI. 22, fig. 7. 
Shell very elongate-ovate, umbilicated, yellowish-white. Nuclear whorls 
very small, obliquely, almost completely immersed in the first of the 
succeeding turns. Post-nuclear whorls evenly, moderately rounded, with 
very faintly shouldered summits, marked by numerous fairly strong, 
equal and equally closely spaced, wavy, spiral striations, and fine retractive 
lines of growth. Periphery and base of the last whorl well-rounded, 
marked like the spire. Suture well-impressed. Aperture ovate, somewhat 
effuse anteriorly, posterior angle acute; outer lip thin; columella very 
oblique, posterior two-thirds straight, and strongly reflected, anterior third 
strongly curved; columellar fold strong, oblique, situated at the insertion 
of the columella; parietal wall covered by a thin callus. Length, 6.4; 
diameter, 3 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 159457. Type locality, 
Killisnoo, Alaska. 
Range. Known only from type locality. 
Odostomia minutissima Dali and Bartsch, 1909 
Plate 60, fig. 4 
Bulletin 68, United States National Museum, 211; PI. 25, fig. 4. 
Shell very small, very regularly narrowly conic, bluish-white. Nuclear 
whorls deeply obliquely immersed in the first of the succeeding turns, 
above which only the tilted edge of the last volution projects. Post- 
nuclear whorls slightly rounded, feebly contracted at the sutures, and very 
narrowly tabulately shouldered at the summit. The spiral thread at the 
periphery and the narrow tabulated summits, which fall a little anterior 
to this, render the suture narrowly channeled. Periphery of the last whorl 
marked by a slender raised thread. Base short, well-rounded, impressed 
at the umbilical area. Entire surface of spire and base marked by slightly 
protractive lines of growth and many, very fine, closely spaced, spiral 
striations. Aperture rhomboidal, posterior angle obtuse; outer lip thin; 
columella slender, curved, slightly revolute, provided with a strong fold 
at its insertion. Length, 3.1; diameter, 1.3 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 206918. Type locality, 
San Diego, California. 
Range. San Diego, California, to Point Abreojos, Lower California. 
[495 ] 
