NOMENCLATURE. 
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retuso-umhilicata. 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, 
duplicat(E. Duplicate ; with a double elevated 
line or stria. 
marginatee. Marginate ; raised, with a promi- 
nent keel. 
Testa. Shell. 
antica. Anterior (part) ; that which is towards 
the spire. 
clavata. Clavate ; 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. 
cylindrico-umbilicata. Cylindrically umbilicate ; 
the umbilicus of which is a cylindric cavity. 
emarginata. Emarginate ; having the margin 
excavated by a sinus. 
exumhilicata. Imperforate ; destitute of a hollow 
umbilicus. 
