194 CERION, GROUP III. 



C. RUDE (Pfeiffer). PI. 33, figs. 54, 55, 56, 57. 



Shell rimate and perforate, solid, cylindric or cylindric oval ; sur- 

 face whitish or yellowish, chalky, the specimens being fossil ; sculp- 

 tured with many rather narrow somewhat oblique riblets, 30 to 32 

 on the last whorl, usually narrower than the intervals. Whorls 10 

 to 11^, but slightly convex. Apex obtuse, the terminal cone with 

 convex outlines. Aperture truncate-rounded, the parietal lamella 

 well developed, usually rather short, axial lamella distinct ; peristome 

 expanded and reflexed, thickened within. 



Length 30, diam. 12 mill, (type of rude). 



Length 29 to 34, diam. 13 mill. 



Length 21, diam. 10^ mill. 



Length 25, diam. 12 mill, (type of latilabris}. 



Length 23, diam. 11^ mill. 



St. Croix: on the plantations "Diamond" "Paradise" and 

 "Blessing," as a quaternary fossil (Riise). 



Pupa rudis PFR., Mai. Bl. ii, 1855, p. 102, pi. 5, f. 1, 2 ; Monogr., 



iv, p. 657 SOWB., C. Icon., pi. 3, f. 21 (bad') Pupa latilabris 



PFR., t. c. p. 103, pi. 5, f. 3. 



This species has not been found living, but occurs in abundance 

 as a fossil. P. latilabris Pfr. (fig. 53) is merely a short specimen, 

 not varietally different. While obtuse at the apex, this species is far 

 less so than C. crassilabre. 



C. YUMAENSE Pilsbry and Vanatta. PI. 33, fig. 58. 



Shell cylindrical, the lower three whorls of about equal diameter, 

 those above tapering rapidly to form a short cone. White, mottled 

 with fleshy-corneous above, or having this or a darker color appear- 

 ing in sparse streaks, or in most or all the intervals between the 

 opaque white riblets, throughout the shell. Surface evenly, regu- 

 larly and closely ribbed, the ribs rounded, about as wide as their in- 

 tervals, usually about 32, but varying from 29 to 37 in number on 

 the penult, whorl. Whorls 9^, the earlier two corneous, first one 

 smooth, next very minutely radially striate. Last whorl rounded 

 below. Umbilical chink much compressed, the tract below it semi- 

 lunar, defined by a groove. Aperture truncate-ovate, brown within ; 

 parietal lamella small, short. Columella truncated obliquely ; lip 

 rather narrowly expanded, not thickened; the parietal callus thin. 



Length 24^ to 26, diam. 9^ mill. 



