212 



CERION, GROUP V. 



Length 29 J, diam. 10; alt. of aperture 11 mill, Cuba. 



C. hyperlissum P. and V., Proc. Acad. Nat. Sci., Phila., 1896, 

 pp. 320, 330, pi. 11, f. 10. 



This species has the unusually long parietal tooth of the Little 

 Cayman Island Cerions. For the rest, it does not differ remarkably 

 from such Cuban forms as C. maritimum. The whorls of the cone 

 are ribless, unlike ribbed members of the maritimum group. 



A form also referable to this species is much striped and maculated 

 with fleshy-brown and white, the riblets being finer. 



C. LONGIDENS n. sp. PI. 32, figs. 23, 24. 



Shell shortly rimate, oblong or subcylindric, very solid and strong ; 

 flesh-colored with nearly white ribs. Sculpture of strong, rather 

 close, subregular ribs, about 30 in number on the penultimate whorl; 

 on the last whorl the ribs become lower and split at the periphery, 

 so that the base is rather finely, irregularly rib-striate. Whorls 9 in 

 short, to 10^ in long specimens, but slightly convex, the last broadly 

 rounded below. Aperture ovate, whitish or pale within ; peristome 

 reflexed and recurved, strongly thickened,' white or pale reddish- 

 brown ; parietal callus rather heavy. Parietal lamella low and 

 rather slender but very long, extending inward to the dorsal side, 

 only slightly curved. There is a low callus or accessory tooth on 

 the left side of the outer end of the parietal lamella. Axial lamella 

 small at the aperture, strong within. 



Length 24, diam. 11.5 mill. 



Length 22.5, diam. 10.5 mill. 



Length 26. 5, diam. 10.8 mill. Cuba: Cabo Cruz (Bland). 



This species has a long parietal lamella like the Little Cayman 

 species. In general external appearance it approaches typical C. 

 glans. The embryonic whorls are either ochre-colored or white. 



C. MARITIMUM (Pfeiffer). PI. 30, figs. 72, 73, 74. 



Shell deeply rimate, cylindric, solid, pure white or sometimes 

 sparsely variegated with reddish-brown or gray, the apex yellowish. 

 Whorls 10-11, nearly flat, the last 3 of about equal diameter, those 

 above forming a terminal cone, the outlines of which are convex 

 below, straight above ; apex obtuse. Sculptured throughout with 

 low and narrow, close, regular riblets. Aperture truncate ovate, 

 pale flesh-tinted or yellowish inside. Parietal lamella small and 



