202 CKRION, GROUP IV. 



and the parietal lamella is better developed, besides being of larger 

 size. The locality of pyymceum is over 100 miles east of that of 

 tenuilabre. Probably the intervening territory will supply inter- 

 mediate forms. 2o specimens examined. 



C. CRASSIUSCULUM ' Torre' P. and V. PI. 32, figs. 36, 37. 



Shell shortly and deeply rimate, cylindrical, rather solid, lustre- 

 less, light brown or yellowish-brown throughout. Latter three 

 whorls of equal diameter, or wider above, those above tapering in a 

 short cone with straight or slightly concave outlines; apex obtuse, 

 rather mammillar. Sculptured with rather close, regular, strong 

 riblets, which are somewhat oblique, varying from as wide to half as 

 wide as the interstices, and about 28 in number on the antepenulti- 

 mate whorl ; becoming obsolete or partially so on the last whorl. 

 Whorls nearly 10, but slightly convex, the last slightly ascending in 

 front. Aperture vertical, with a very small, short parietal tooth T 

 and moderate axial fold ; peristome blunt, expanded, subreflexed r 

 the terminations distant, connected by a moderate parietal callus. 



Length 21, diam. 8^, long axis of aperture 8^ mill. 



Length 20, diam. 9^, long axis of aperture 8^ mill. 



Eastern Cuba: Cayo Jii/'n, Baracoa (Prof, de la Torre, F. E, 

 Blanes). 



Cerion crassiusculum Torre, PILSBRY and VANATTA, Proc. Acad, 

 N. S., Phila., 1898, p. 478, f. 7, 8. 



There is a small form, alt. 13^, diam. 6^, length of aperture f> 

 mill., having all the characters of the larger except that there are 

 only 8 whorls (fig. 37). 



The last whorl in this species is half the total length of the shell 

 or a trifle more, and upon it the ribs are weak or wholly obsolete. 

 Compared with C. microdon, it differs in the concave instead of con- 

 vex outlines of the terminal cone, and the color. It differs from C. 

 tenuilabre in the coarser sculpture ; and from both in the compara- 

 tively smooth last whorl. 



Var. SMITHII ' Blanes' Pilsbry, n. v. PI. 32, fig. 38. 



Shell similar in form but somewhat larger, and smooth, fine riblets 

 appearing on several whorls of the cone. Whorls 10, those of the 

 cone convex, the rest nearly flat. Lip reflexed and somewhat thick- 

 ened. Length 2f)7r, diam. 10, long axis of aperture 10 mill. 



Sagua de Tanamo (F. E. Blanes). 



A smooth form, from the same coast. 



