154 



suture. Aperture, very oblique, approaching to straight on the left, 

 and much expanded, especially above on the right. Peritreme, 

 slightly sinuate above. Umbilicus, narrow, greatest breadth 0'24. 

 Umbilical keel, strongly produced within, rather flat outside, conti- 

 nuous round the whorl. Operculum, rather concave and convex on 

 the lower side between the types of C. seminudus and C. Jamaicensis ; 

 whorls 6, the margins rising higher before dilation than in C. semi- 

 nudus, and being much broader and rounder than in C. Jamaicensis. 

 Height 0'61, greatest breadth O'SS, least breadth - 7. 



This shell has been distributed by Adams as a variety of C. varians. 



§IV. 



C. Jamaicensis, Chemn. See Cat. Phan. p. 13. 



I will only add to that description, that the operculum, though 

 generally planular, is sometimes very triflingly concave, and that the 

 last lamella whorl is wide apart from the edge. 



C. dentistigmattjs, Chitty. Yallahs Hill and Portland. 



Form, depressed-conic. Colour, dark olive brown, strong red-brown 

 at the apex and within the aperture. Sculpture, coarse lines of 

 growth down to the last quarter of the penult whorl, thence coarse 

 corrugation till it becomes extremely coarse, wide and highly raised 

 at the back of the last whorl, and becomes obsolete at the back of the 

 aperture ; below the periphery, smooth with about 14 deep eccentric 

 tooth-like indentations running up to the umbilical keel (thence the 

 name) ; lines of growth within the umbilicus, not coarse. Spire, well 

 elevated, somewhat mammiform, with concave outlines. Whorls, 

 5^, much rounded with a deep suture, last very large and ventricose. 

 Aperture, rather oblique, dilated on the right side, large, red-brown 

 within. Peritreme, very sinuate above. Umbilicus, largely open and 

 funnel-shaped, greatest breadth 0*36. Umbilical keel, very promi- 

 nent and wide. Operculum, planular above, lamina of 9 whorls rising 

 higher and much closer than in C. Jamaicensis, which it much re- 

 sembles otherwise ; below the margins, the lamina spreads out as in 

 C. seminudus, so as to touch each consecutive whorl, and appear to be 

 appressed to the plane, but are de facto detached. Last whorl close 

 to the edge, rather concave below. Height 0*9, greatest breadth 1 ■ 13, 

 least breadth 0*9. 



This shell may be readily known by the tooth-marks which give 

 rise to its name. Its operculum and size distinguish it from 

 C. Novce-Spei. 



C. novus-saltus, Chitty. New Forest. 



Form, depressed-conic. Colour, brown. Sculpture, throughout 

 fine somewhat close regular striae of growth, which give a silky 

 appearance. Spire, moderately elevated, with convex outlines. 

 Whorls, 5-j, well rounded, with a deep suture. Aperture, circular, 

 not expanded. Peritreme, simple. Umbilicus, greatest breadth - 32. 

 Umbilical keel, almost obsolete, just visible. Operculum, concave 



