222 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



The type (Cat. no. 168827 U.S.N.M.) was dredged by the U. S. 

 Bureau of Fisheries station 3180, in 24 fathoms, temp. 50. °7, off 

 the Farallones Islands, CaUfornia. It has five post-nuclear whorls, 

 and measures: Length 5.5 mm., diameter 2.7 mm. 



ODOSTOMIA (AMAURA) SILLANA, new species. 



Plate 28, fig. !). 



Slieh short, conic, yellowisli wdiite. (Nuclear whorls eroded.) 

 Post-nuclear whorls well rounded, slightly overhanging. Summits 

 appressed, marked by almost vertical lines of growth and numerous 

 closely spaced, wavy, microscopic, spiral striations. Suture well 

 marked. Periphery of the last whorl well rounded. Base rather 

 short, inflated, narrowly umbilicated and marked like the spire. 

 Aperture broadly ovate, somewhat effuse anteriorly. Posterior angle 

 acute; outer lip thin, strongly curved in the middle; columella slen- 

 der, strongly curved and reflected anteriorly, provided with a weak 

 fold near its insertion; parietal wall glazed by a thin callus. 



The type (Cat. no. 168809, U.S.N.M.), collected by Doctor Dall 

 west of Amaknak Island, Unalaska, in 60 fathoms, on stony bottom. 

 It has five and one-half post-nuclear whorls, and measures: Length 

 5.6 mm., diameter 2.8 mm. 



ODOSTOMIA (AMAURA) TALPA, new species. 

 Plate 27, fig. 9. 



Shell stout, rough, very broadly conic, narrowly umbilicated. Nu- 

 clear whorls small, deeply obliquely immersed in the first post- 

 nuclear turn. Post-nuclear whorls with quite strong concavely 

 shouldered summits, the rest well rounded (usually showing decided 

 erosion marks which coincide largely w4th the lines of growth) . The 

 parts bearing the- original surface show traces of exceedingly fine 

 spiral striations. Periphery and base of the last whorl rather inflated, 

 well rounded, the latter narrowly umbilicated, marked like the spire. 

 Aperture broadly oval, posterior angle obtuse; outer lip rather thick, 

 columella stout, thick, somewhat flexuose and reflected, provided 

 with a strong fold a little anterior to the umbilicus; parietal wall 

 covered by a thin callus. 



The type (Cat. no. 204027, U.S.N.M.) has seven post-nuclear whorls, 

 and measures: Length 8 mm., diameter 3.8 mm. It and two other 

 specimens were collected by Mrs. Kate Stephens at Mole Harbor, 

 Alaska. Two additional specimens (Cat. no. 159472 U.S.N.M.) were 

 dredged by Doctor Dall in 12 fathoms in Sitka Harbor, Alaska. 



