164 Panama Shells. LITTOKINIDJE. 



Habitat. Panama; C. B. A. ! 

 2 specimens were found. 



CHEftllVITZIA. The following species of this genus, 

 with the exception of 0. communis and C. emarginata, have the 

 axis of the first whorl nearly or quite perpendicular to the axis 

 of the other whorls, constituting a subacute, subtransparent, 

 smooth and colorless apex. This remark, however, cannot yet 

 be applied to C. major, the unique specimen of which has lost 

 the apex. 



As in Vitrinella and in some other groups of minute tropical 

 species, the number of individuals is small in proportion to the 

 number of species. The following 12 species are represented 

 by 129 specimens, of which 90 belong to one species, and 21 

 others belong to 2 species, leaving 9 species represented by only 

 18 specimens. 



219. Cheumitzia aculews. Nov. sp. 



Shell conic, very slender : white : with, on each whorl, about 

 seventeen obtuse ribs, which terminate abruptly at the periphery 

 of the last whorl : spire with the outlines rectilinear except near 

 the apex : whorls twelve, moderately convex, with a well im- 

 pressed suture ; last whorl with the periphery subangular : 

 aperture subovate : labrum thin : columella scarcely curved : 

 umbilicus wanting. 



Mean divergence about 13 ; length .18 inch ; breadth .04 

 inch ; length of spire .145 inch. 



Station. Unknown. 



Habitat. Panama ; C. B. A. ! 



4 specimens were found in the sand. 



220. Chemnitzia acuuiinata. Nov. sp. 



Shell fusiform conic : dingy white : with about sixteen or 

 eighteen transverse somewhat oblique ribs, which terminate ab- 



