ON LAND AND FRESH WATER MOLLUSCA OF 

 LOWER CALIFORNIA. No. 3. 



BV J. (J. COOPER. 



This paper is a continuation of the article on p. 207, 

 where a part of the Lower California land and fresh- 

 water shells are described or mentioned. 



CoLUMNA RAMENTOSA J. G. C. 1891. Plate xiii, fig. I. 



Rhodea californica var. ranientosa, 1. c, p. 215, etc. 



Nuclear whorls 2, turbinate, abruptly truncate, with 

 numerous fine vertical ribs, on third becoming oblique 

 and parallel to lines of growth, on all the others crossed 

 b}- 10 to 15 transverse striee parallel to sutures, produc- 

 ing a file-like sculpture. Whorls 13 to 16 slightly con- 

 vex, cylindrical and nearly equal, the 7th to nth usually 

 largest, then diminishing and penultimate whorl also nar- 

 rowed vertically to size of 8th. Body whorl swollen on 

 left side, and with 2 deep constrictions about equidistant 

 between base and suture, extending from outer side of 

 lip to middle of dorsal surface, not visible inside of mouth. 

 Peristome slightly expanded and thickened, suboval, 

 pointed above, inner lip continuous across columella, 

 leaving an umbilical sinus, which continues as a perfora- 

 tion throughout axis of shell, mouth of shell large, ex- 

 panded, base rounded. Immature shell wuth the base an- 

 gular, forming a rhomboid mouth. 



Length 0.95 to i inch, breadth 0.18; mouth 0.19 long, 

 0.17 wide; color white, translucent. 



Habitat. — Foothills near San Jose del Cabo, Lower 

 California, 15 specimens near edge of lagoons, one in 

 a cave. \V. E. Bryant and G. Ei<.en. 



CoLUMNA (var.?) abbreviata J. G. C. 1892. Plate 

 xiii, fig. 2. See ante, p. 215. 



Nuclear whorls, ly^ , vertically fiattened. the others re- 



•2d Ser. Vol. III. May 5, 1893. 



