NOMENCLATURE . 2 1 



retnso-2imli.llcata. Retuso-umbilicate ; the spire 

 being so much impressed as to seem rather 

 concave than convex. 



Suture. Sutures of the whorls ; the spiral 

 line of connexion between them. 



diipUcatce. Duplicate; with a double elevated 

 line or stria. 



marginatce. Marginatej raised^ with a promi- 

 nent keel. 



Testa. Shell. 



antica. Anterior (part) ; that which is towards 

 the spire. 



clavata. Clavate 5 club-shaped, thicker above and 

 elongated towards the base. 



convoluta. Convolute ; when the exterior whorls 

 spirally involve the interior. 



corticata. Corticate ; covered with an epidermis. 



cyl'mdrico-umlillcata. Cylindrically umbilicate ; 

 the umbilicus of which is a cylindric cavity. 



emarginata. Emarginate ; having the margin ex- 

 cavated by a sinus. 



exumbilicata. Imperforate; destitute of a hollow 

 umbiUcus. 



