354 PROCEEDINGS OF THE NATIONAL MUSEUM. vol. 56. 



ish; nucleus minute, glassy, of about two depressed whorls, followed 

 by three strongly appressed subsequent turns; periostracum thin, 

 dehiscent, brownish; sculpture of fine faint incremental, and still fainter 

 obsolete spiral striae; aperture very oblique, body with a heavy white 

 callus, umbilicus wide, funicular, with a brown slightly convex mar- 

 ginal band; height, 31; height of aperture, 27; diameter, 24 mm. 

 U. S. Nat. Mus. Cat. No. 46544. 



Type-locality. — Panama, Thomas Bridges. 



This species has generally been circulated under the name of R. oiis 

 Broderip and Sowerby, but that designation has been used to cover 

 a number of probably distinct forms. 



SINDM PAZIANUM, new species. 



Shell small, grayish white, depressed, with a translucent smooth 

 nucleus of a whorl and a half and two subsequent whorls; suture 

 distinct, outline oval, axial sculpture of faint incremental lines; spiral 

 sculpture of fine incised lines, sometimes close, sometimes with wide 

 interspaces, but barely perceptible except with a lens; last whorl pro- 

 duced, body with a slight glaze of enamel; pillar lip reflected with 

 an umbilical chink behind the reflection, base slightly flattened; 

 longer diameter, 9; shorter diameter, 7; height, 2.5 mm. U. S. Nat. 

 Mus. Cat. No. 211406. 



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

 Lower California, in 26| fathoms, shelly bottom. 



This is next to the smallest of the group on the Pacific coast and 

 ranges from Catalina Island, California, to Panama, usually in deeper 

 water. 



SINUM KEKATIUM, new species. 



Shell small, white, convex, suborbicular, with a minute subglobular 

 nucleus and three subsequent whorls; sutm-e distinct and deep; 

 spiral sculpture of sharp, rather regular grooves with wider inter 

 spaces crossed by fine incremental lines, which in places give a punc- 

 tate effect to the grooves under the lens; the grooves on the base 

 closer and finer; pillar lip slightly reflected over an umbilical chink, 

 body with a thin glaze; long diameter, 6.5; shorter diameter, 5; 

 height, 3.5 mm. U. S. Nat. Mus. Cat. No. 206152. 



Type-locality.— C&talinsi Island, California; collected by W. H. Dall. 



This is the smallest Pacific coast species, relatively more convex, 

 and more regularly sculptured than the preceding. 



ELACHISINA, new genus. 



Shell minute, elevated, with naticoid spiral sculpture, umbilicate. 

 Type. — ElacMsina grippi DaU, new species. 



ELACHISINA GRIPPI, new species. 



Shell minute, having somewhat the aspect of a short Cingula, white, 

 with a very thin periostracum, and four well-rounded whorls, exclusive 



