188 Panama Shells. TROCHID^L 



wrinkles, which are obsolete on the upper part of the whorls ; 

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

 yex, 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. 



Habitat. Panama ; C. B. A. ! 



3 specimens were found in the calcareous sand. 



266. Vitriiiella regularis. 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 ; C. B. A. ! 



1 specimen was found in the calcareous sand. 



267. Titrinella eminuda. Nov. sp. 



Shell discoidal : white : above with excessively minute striae 

 of growth ; beneath covered with spiral striae : 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. 



