188 Panama Shells. TROOHlDiE. 



■wrinkles, which are obsolete on tlie upper part of tlie whorls ; 

 apex obtuse : spire flat : whorls nearly three, moderately con- 

 vex, with a distinct suture; last whorl very large: aperture 

 orbicular, very oblique : lip slightly thickened : umbilicus 

 deep. 



Mean divergence 180° ; greatest breadth .037 inch ; least 

 breadth .031 inch ; height .015 inch. 



Station. — Unknown. 



Hahitat. — Panama ; C. B. A. I 



3 specimens were found in the calcareous sand. 



266. Titrinella re§^ularis. Nov. sp. 



Shell subdiscoidal : pearl white : smooth and shining, with 

 an impressed spiral line just below the suture : apex subacute : 

 spire convex, moderately elevated : whorls four and one-half 

 convex, with a distinct suture; last whorl somewhat ventri- 

 cose: aperture nearly orbicular: lip thin: umbilical region 

 deeply indented. 



Mean divergence about 120° ; greatest breadth .07 inch ; 

 least breadth .06 inch ; height .05 inch. 



Station. — Unknown. 



Habitat. — Panama ; 0. B. A. I 



1 specimen was found in the calcareous sand. 



267. Titrinella seminuda. Nov. sp. 



Shell discoidal : white : above with excessively minute strias 

 of growth ; beneath covered with spiral striss : apex obtuse : 

 spire scarcely elevated, convex : whorls three, moderately con- 

 vex, with a distinct suture; last whorl with the periphery sub- 

 angular : aperture orbicular, very oblique : lip thin : umbilicus 

 narrow, deep. 



