136 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



of these cords is at the periphery, the third at the posterior termina- 

 tion of the anterior third between the sutures, which it renders 

 strongly angulated. Sutures constricted. Periphery and base of the 

 last whorl well rounded, marked by the continuation of the axial ribs, 

 and about eight slender spiral lirations. Aperture broadly oval; 

 posterior angle acute ; outer lip thin, showing the external sculpture 

 within; columella slender, slightly curved, decidedly oblique and 

 revolute, provided with a slender fold at its insertion; parietal wall 

 covered with a strong callus. 



Two specimens (Cat. no. 162734, U.S.N.M.) were dredged at U. S. 

 Bureau of Fisheries station 2823, in 26 fathoms, on broken shell bot- 

 tom, off Cacachitas, Gulf of California. The larger of the two speci- 

 mens has six post-nuclear whorls and measures: Length 2.4 mm., 

 diameter 0.7 mm. 



The type which is on tablet 1984, Liverpool collection, British 

 Museum, and another specimen were collected on Spondylus at 

 Mazatlan. 



ODOSTOMIA (BESLA) CALLIMORPHA, new name. 



Plate 13, fig. 5. 



Chrysallida pumila Carpenter, Proc. Cal. Acad. Sci., vol. 3, 1866, p. 219; not 

 Odostomia pumila A. Adams, 1861. 



Shell very small, pupiform, milk-white. Nuclear whorls com- 

 pletely immersed. Post-nuclear whorls flattened, slightly contracted 

 at the sutures, moderately shouldered at the summit, marked by 

 strong, depressed, rounded, almost vertical axial ribs, of which 22 occur 

 upon all but the first whorl, which is smooth. Intercostal spaces 

 about as wide as the ribs, crossed by three slender, spiral lirations on 

 the anterior half of the whorls between the sutures. Sutures sub- 

 channeled. Periphery and base of the last whorl well rounded, 

 marked by the continuations of the axial ribs, which extend almost 

 undiminished to the umbilical area and five equal slender, spiral lira- 

 tions on the posterior half of the base. Aperture broadly oval ; pos- 

 terior angle acute; outer lip thin, showing the external sculpture 

 within; columella strongly curved, slightly revolute, reenforced on its 

 posterior half by the base, provided with a strong fold at its insertion. 



The type (Cat. no. 15565, U.S.N.M.) comes from San Pedro, Cali- 

 fornia. It has five post-nuclear whorls and measures: Length 1.5 

 mm., diameter 0.6 mm. 



Subgenus CHRYSALLIDA Carpenter. 



Chrysallida Carpenter, Cat. Mazatlan Shells, 1856, p. 416. = N'oemia De Folin, 

 Fonds de la Mer, 1873, p. 314. Type. — No'emia angusta De Folin; Noe- 

 miamea De Folin, Zool. Rec, 1885, p. 94 (Mollusca). Same type. Not 

 No'emia Pasco, 1857. 



Odostomias having strong axial ribs crossed by equally strong 

 spiral keels between the sutures, the intersection of these two ele- 



