NO. 2295. NEW NORTH PACIFIC MOLLUSKS—DALL. 297 



pillar which has a strong plait with a groove behind it, the body with 

 a slight glaze; length, 6.7; diameter, 2.5 mm. U. S. Nat. Mus. Cat. 

 No. 218410. 



Type-locality.— Msigdsilena Bay, Lcwer California, collected by 

 C. R. Orcutt. 



RETUSA XYSXaOM, new species. 



Shell minute, white, subcylindric, the aperture as long as the shell, 

 the whorls involved, with a deep pit at the apex, slightly wider in 

 front; very little constricted around the middle; sculpture cf ex- 

 tremely fine close longitudinal grooves covering the whole surface; 

 the base produced, imperforate; the aperture very narro^v, outer lip 

 straight, as long as the shell, simple, sharp, rounding into the base; 

 length of the shell, 3; maximum diameter, 1 mm, U. S. Nat. Mus. 

 Cat. No. 273985. 



Type-locality. — Dredged at San Diego, California, by C. R. Orcutt. 

 Also found at San Pedro. 



RETUSA PAZLANA, new species. 



Shell minute, white, with an involved spire, above which is a rather 

 large perforation; the general form is subcylindric, wider anteriorly, 

 obscurely widely constricted about the middle of the shell, rounded 

 at the summit, the aperture as long as the shell; sculpture wholly 

 axial, of fine, sharp, close vertical grooving extending over the whole 

 shell, with no perceptible spiral sculpture; aperture very narrow 

 except at the base, rising somewhat above the summit of the shell; 

 base rounded, pillar simple with no chink behind it; height, 3; maxi- 

 mum diameter, 1.4 mm. U. S. Nat. Mus, Cat. No. 211418. 



Type-locality. — U. S. Fish Commission station 2823, off La Paz, 

 Gulf of California, in 26 fathoms broken shell, 



RETUSA GALAPAGANA, new species. 



Shell minute, white, involved, with a deep pit at the apex, the 

 aperture as long as the shell; form subcylindric, the diameter slightly 

 larger anteriorly, the middle of the whorl feebly constricted, the 

 whorl at the summit rounded; the entire shell axially closely sharply 

 grooved; outer lip thin, sharp, aperture very narrow behind the base, 

 pillar simple, rounding into the basal lip; height of shell, 3; maximum 

 diameter, 1.5 mm. U. S. Nat. Mus. Cat. No. 194976&. 



Type-locality. — U. S, Fish Commission station 2813, at the Gala- 

 pagos Islands, in 40 fathoms, coral sand; temperature at surface, 

 81° F. 



VOLVULELLA COOPERI, new species. 



Shell subcylindric, white, in the young with a very short spine, the 

 adult having the spine obsolete or even absent, involved, bluntly 

 rounded at each extremity, the aperture as long as the shell: smface 



