196 CERION, GROUP IV. 



Length 161-18, diam. 7J mill. 



Length 13, diam. 7 mill, (shortest specimen). 



In a large quantity of specimens examined there are no intergrades 

 with yumaense. As in that species, the young shells are without 

 teeth, other than a small axial fold. One of the Yuma specimens is 

 figured (fig. 60). 



C. CAYMANENSE n. sp. PI. 44, figs. 85, 86. 



Shell shortly rimate, cylindric with rather straightly conic termi- 

 nal cone and obtuse apex; solid and strong;, grayish-white, very 

 sparsely flecked with dull purple, generally more copiously marked 

 on the cone. Sculpture of regular, crowded riblets, somewhat wider 

 than their intervals, 25 to 28 on the penultimate whorl, each rib a 

 little swollen at the upper end, crenulating the sutures. Whorls 8^ 

 to 9J, but slightly convex, the last ascending in front. Aperture 

 ochre brown inside ; peristome whitish, somewhat reflexed, thick ; 

 parietal callus moderately heavy, appressed. Parietal tooth small and 

 very short ; axial tooth small. 



Length 19, diarn. 8 mill. 



Length 17.3, diam. 7.6 mill. 



Grand Cayman Island (C. B. Taylor). 



This species resembles C. yumaense var. sallei of S. Domingo, but 

 its apex is less obtuse, the peristome much thicker, and the ribs 

 stouter. The specimens described were received from Mr. G. H. 

 Clapp, and collected by Mr. C. B. Taylor, of Kingston, Jamaica, 

 who found them on a " honeycomb " lime rock and red earth forma- 

 tion, on the north side of the island. 



IV. Group of C. cyclostomum. 



Fine-ribbed or striate and rather small species, with the parietal 

 tooth short and central, sometimes obsolete. All are from Cuba, 

 occurring the whole length of the island. The species are difficult 

 to discriminate. 



C. CYCLOSTOMUM (Kiister). PI. 32, figs. 13, 14. 



Shell ovate, cylindric, less rapidly tapering above than uva, and 

 less tapering below, rather thin, glossy. The apex is smooth, the 

 rest of the surface sculptured with very numerous, fine, somewhat 

 acute riblets, separated by intervals of the same width. On the upper 



