CERION, GROUP VI. 221 



Length 27, diam. 12 mill. 



Length 21, diam. 14.5 mill. 



Length 25.5, diam. 12 mill. 



Bahamas : Long, or Berry Island (J. A. Stevenson). 



Cerion stevensoni DALL, Nautilus, xiv, p. G5 (Oct. 1, 1900). 



This species is closely allied to C. feh's P. and V., differing from 

 that species in the flatter, wider lip, absence of any axial lamella 

 visible in the aperture, the much broader, somewhat funnel-shaped 

 umbilical area, and in the sculpture of the base ; the ribs in C.felis 

 extending to thi verge of the umbilicus, while in C. stevensoni they 

 cease at a rounded cord or keel, which defines the base of th". shell. 

 Below this cord the base is very convex. 



The specimen figured has 14 strong, rude ribs on the penultimate, 

 13 on the last whorl ; on the antepenultimate whorl there are 16 

 ribs. As in C. felis, the ribs are so strong that they produce cor- 

 responding depressions on the inside of the shell ; and the densely 

 crowded rib-striae of the third whorl give way rather abruptly to the 

 coarse ribs of those succeeding. 



Figured from one of the type lot, kindly supplied by Professor 

 Wm. H. Ball. 



C. FELIS Pilsbry and Vanatta. PI. 44, figs. 72, 73. 



Shell strong, cylindrical, with a short but deep umbilical chink; 

 the spire terminating in a short, straightly conic, rather acute cone; 

 dull purplish brown. Sculpture of very strong, rough ribs, much 

 narrower than the intervals, about 16 in number on the penultimate 

 and next earlier whorls, the whole surface scored by deep, irregu- 

 larly crowded spiral lines. Whorls 10^-, the first smooth, next 1^ 

 obliquely striate, the rest ribbed ; the last whorl has the base defined 

 by a shallow furrow encircling below the periphery, the ribs continuing 

 to the umbilical excavation, which is abruptly bounded by a slight 

 ledge. Aperture angularly ovate, dull purplish-brown within, the 

 parietal lamella compressed, moderately long, axial lamella incon- 

 spicuous; peristome rather narrowly reflexed, thickened, whitish, 

 the parietal callus rather thin. Length 28, diam. 11^ mill. 



Bahamas: Cat Island (Thos. Bland). 



C. felis P. and V., P. A. N. S., 1895, p. 206 (June 18, 1895); 

 1896, p. 322, pi. 11, f. 29. 



Related to C. stevensoni Dall, but longer, with far smaller umbil- 

 ical excavation, and having the ribs continued upon the base. 



