202 BULLETIN 68, UNITED STATES NATIONAL MUSEUM. 



sutures well marked. Periphery of the last whorl subangulated. 

 Base attenuated, rather suddenly contracted below the periphery, 

 which gives tlie space between the periphery and the umbilical area 

 a concave aspect. Entire surface marked by fine lines of growth and 

 many fine, closely placed spiral lirations, five of which are a little 

 stronger than the rest and divide the space between the sutures into 

 subequal areas. There are about 30 of these threads upon the last 

 turn between the summit and the periphery and a1)out 60 on the base. 

 Aperture very large, patulous anteriorly; outer lip thin at the edge 

 but very thick within; columella decidedly curved, and revolute,' 

 reenforced to the very edge by the attenuated l)ase, provided with a 

 strong oblique fold at its insertion. 



The type and a young individual (Cat no. 155216) were collected 

 by J. G. Swan at Neah Bay, Washington. It has the last four whorls 

 (the nucleus and probably the first post-nuclear turn being lost) and 

 measures: Length 6.2 mm., diameter 3.8 mm. 



ODOSTOMIA (EVALEA) COLUMBIANA Dall and Bartsch. 



Plate 23, fig. 1. 



Odostomia (Evalca) coliivibiana Dall and Bartsch, Proc. U. S. Nat. Mus., vol. 

 33, 1907, p. 525, pi. 47, fig. 9. 



Shell large, elongate-conic, white. Nuclear whorls small, vitreous, 

 planorboid, deeply ol)liquely immersed in the first of the succeeding 

 turns, above which only the tilted edge of the last volution is visible. 

 Post-nuclear whorls increasing regularly in size, well rounded, very 

 narrowly roundly shouldered at the summits, which renders the sut- 

 ures well marked. Periphery of the last whorl somewhat inflated. 

 Base well rounded, attenuated anteriorly to reenforce the columella. 

 Entire surface covered by numerous somewhat wavy, subequal and 

 subequally closely placed spiral lirations, of w^hich about 40 occur 

 between the summit and the periphery and about an equal number on 

 the base of the last whorl. Aperture large, decidedly patulous ante- 

 riorly; posterior angle acute; outer lip thin at the edge, very thick 

 within; columella curved and strongly reflected, free only at its ante- 

 rior extremity, provided w4th a strong oblique fold at its insertion. 



The type and five specimens (Cat. no. 126658, U.S.N.M.) were col- 

 lected by Dr. C. F. Newcombe at Victoria, Vancouver Island, British 

 Columbia. It has six post-nuclear whorls and measures: Length 8.3 

 mm., diameter 4.2 mm. Three other specimens (Cat. no. 196245, 

 U.S.N.M.) w^ere dredged by the Bureau of Fisheries steamer Albatross 

 at station 4213, off Port Townsend, Washington, in 23 to 25 fathoms, 

 gray sand and broken shell, bottom temperature 51 °. Another (Cat. 

 no. 196246, U.S.N.M.) at stationat 4203, Fort Rupert, British Colum- 

 bia, in 25 to 30 fathoms, volcanic sand and gravel and broken shell 

 and sponge, bottom temperature 49°.l. 



