512 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. xxxm. 



axis of the later whorls. Post-nuclear whorls slightly convex, some- 

 what contracted at the periphery and slightly shouldered at the sum- 

 mit; traversed by about 20 to 24 strong, well-rounded, somewhat 

 oblique axial ribs, which continue faintly over the decidedly angular 

 periphery of the last whorl and the base to the umbilical region; these 

 ribs are consideral)ly enfeebled on the last whorl of old shells and fre- 

 quently become almost obsolete on these. The exposed portion of the 

 whorls is traversed by five spiral grooves, which appear most promi- 

 nenth' in the shallow and broad intercostal spaces, and less so on the 

 ribs; these deep spiral lines are regularly spaced, leaving a broader 

 interval on the middle of the exposed portion of the whorl; the base 

 of the last whorl is likewise ornamented by spiral grooves, but here 

 they appear less developed than on the spire. In addition to this the 

 entire surface of the shell is marked by numerous very fine, somewhat 

 wavy, spiral and axial strife, which show most prominentl}" on the last 

 whorl and base, and give the shell a very minutely reticulated second- 

 ary sculpture. At irregular intervals the whorls are marked b}^ thick 

 callous varices, which are usually of a lighter color than the remainder 

 of the shell. Aperture large, subquadrate; posterior angle acute; 

 outer lip thin, having three strong internal lirations, joining the whitish, 

 short, straight, revolute columella at a little less than a right angle. 

 By transmitted light two spiral, light color-bands become apparent on 

 the inside of the lip, each of which is bordered by a zone of a darker 

 color than the remaining shell. The general color effect of the exte- 

 rior is that of a flesh-colored shell, covered by a dark epidermis, which 

 is stretched tight over the ribs, permitting the lighter color beneath to 

 shine through it at their summits. 



Doctor Carpenter's type (Cat. No, 15315J, U.S.N.M.) was collected 

 at Monterey, California. It has 11 post-nuclear whorls and measures: 

 Length 11.1 mm,, diameter 3.2 ram. The specimen figured (Cat. No. 

 150983, U.S.N.M.) is from San Pedro, California. It has 13 post- 

 nuclear whorls and measures: Length 12.8 mm., diameter 3.6 mm. 



The U. S. National Museum has five lots of this species: Cat. No. 

 1631 S?* is the type from Monterey, California; Cat. No. 196239, four 

 specimens dredged by the Bureau of Fisheries steamer Alhatro^H at 

 station No. 2902, ofi Santa Rosa Island, in 53 fathoms, fine gray sand 

 and mud, with a bottom temperature of 45°; Cat. No. 196240, ten speci- 

 mens from San Pedro, collected by Mrs. T. S. Oldroyd; Cat. No. 

 150983, three individuals, one of which i.-* figirred, dredged by Mrs. 

 Oldroyd in 4 fathoms, at San Pedro; Cat. No. 46505, two shells from 

 San Diego in the Stearns collection. In addition to these, specimens 

 have been determined for Mr. Berry, from Monterey, 12 to 39 fathoms; 

 Universit}^ of California, oti Catalina Island; Mrs. Oldroyd and Mr. 

 Lowe, at San Pedro; Mr. Kelsey and Mr. Arnold, from San Diego. 



