168 Panama Shells. LITTORINID^E. 



eleven or twelve very prominent strong compressed ribs : in the 

 interspaces with fine spiral stride, of which five or six are seen 

 on the penult whorl : apex with the axis oblique : spire with 

 the outlines curvilinear : whorls seven, margined above with a 

 spiral compressed ridge, moderately convex, with a well 

 impressed suture : last whorl with the periphery rounded : 

 aperture small, oblique, ovate : labrum thin : labium with a 

 distinct deposit : umbilicus wanting. 



Mean divergence about 28 ; length .115 inch ; breadth .042 

 inch ; length of spire .08 inch. 



Station. Unknown. 



Habitat. Panama ; C. B. A. ! 

 2 specimens were found. 



227. Clienmitzia Paiiameiisis. Nov. sp. 



Shell long, conic : white : with, on each whorl, about twenty- 

 seven oblique ribs, which become obsolete on the middle of the 

 last whorl, the anterior part of which is very smooth : spire 

 with the outlines nearly rectilinear : whorls twelve, moderately 

 convex, with a well impressed suture : last whorl sub-angular at 

 the periphery : aperture obliquely ovate : labrum thin : colu- 

 mella nearly straight : umbilicus wanting. 



Mean divergence about 17 ; length .22 inch ; breadth .055 

 inch ; length of spire .17 inch. 



Station. In the sand between high water and half tide 

 levels. 



Habitat. Panama; C. B. A. ! 



11 specimens were found on the reef. 



228. Chemnitzia similis. Nov. sp. 



Shell long, conic : white : with, on each whorl, about twenty- 

 six rather obtuse ribs, which terminate abruptly on the peri- 

 phery of the last whorl : spire with the outlines nearly rectili- 



