CERITHIUM. PLEUROTOMA. 79 



C. LiTERATUM. Turreted, ventricose; whorls 

 with numerous dotted muricated striae, and a row 

 of tubercles above ; white^, prettily dotted with red 

 or black; outer hp forming an angle with the 

 body-whorl; canal truncated, f. W. 28. 163. 



C. TUBERCULATUM. Ovatc-conic, ventricose 

 at the base; whorls finely striated transversely, 

 brownish white, coronated with one row of small 

 black tubercles, the body -whorl with several; 

 apex white; beak short and truncated. 1. W. 

 25. 38. 



C. PERVERSUM. Reversed, cylindrically sub- 

 ulate, slender, pale rufous, with three transverse 

 granular striae on each whorl ; whorls flattened ; 

 base plano-concave ; canal straight, slightly pro- 

 minent. B. f . W. 28. 167. 



C. cosTATUM. Turreted, deep brown, with 

 the ten or eleven whorls longitudinally ribbed ; 

 aperture sub-orbicular ; beak sub-truncated ; lip 

 expanded, f. B. W. 25. 43. 



PLEUROTOMA. 



Shell either turreted or fusiform ; terminated in- 

 feriorly by a straight canal more or less elon- 

 gated; lip at its upper part having a fissure or 

 emargination. 



P. BABYLONIA. Fusiform, turreted, trans- 

 ^ versely carinated and banded, white ; bands 



