CLASS GASTROPODA 
161 
Type in United States National Museum, No. 212033. Type locality, 
United States Bureau of Fisheries Station 2932, in twenty fathoms, off 
San Diego, California. 
Range. Known only from type locality. 
Odostomia lucca Dali and Bartsch, 1909 
Plate 58, figs. 8, 8 a 
Bulletin 68, United States National Museum, 148; PI. 15, figs. 8, 8a. 
Shell broadly conic, milk-white. Nuclear whorls large, obliquely im¬ 
mersed in the first of the succeeding turns, above which the tilted edge 
of the last volution only projects, which shows five strong spiral threads. 
Post-nuclear whorls well-rounded, strongly contracted at the sutures, 
appressed at the summits with a sloping shoulder that extends from the 
summit to the second spiral keel, marked by narrow, decidedly elevated, 
retractive axial ribs, of which sixteen occur upon the first and second, 
eighteen upon the third, and twenty-two upon the penultimate turn. In 
addition to the ribs, the whorls are marked between the sutures by four 
spiral keels, which equal the ribs in strength and render them decidedly 
nodulous at their junction. The spaces inclosed by the ribs and cords are 
well-impressed rectangular pits whose axis coincides with the spiral sculp¬ 
ture. Sutures subchanneled, showing a portion of the first basal keel in the 
last two volutions. Periphery of the last whorl marked by a broad channel, 
crossed by the axial ribs, which terminate at the posterior edge of the first 
basal keel. Base of the last whorl well-rounded, marked by five, subequal 
and subequally spaced, spiral lirations, separated by broad spaces, which 
are marked by numerous prominent axial threads. Aperture broadly oval; 
posterior angle obtuse; outer lip thin, showing the external sculpture 
within; columella moderately strong, curved, re-enforced by the base, 
provided with a weak fold at its insertion; parietal wall covered with a 
thin callus. Length, 4; diameter, 1.4 mm. (Dali and Bartsch.) 
Type in United States National Museum, No. 206898. Type locality, 
San Diego, California. 
Range. Monterey to San Diego, California. 
Odostomia montereyensis Dali and Bartsch, 1907 
Plate 57, fig. 4; Plate 59, fig. 6 
Proceedings of the United States National Museum, 33:516; PI. 46, fig. 4. 
Shell broadly conic, milk-white to subdiaphanous. Nuclear whorls 
smooth, largely immersed in the first of the succeeding turns, above which 
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