CERION, GROUP IX. 241 



irregularly spaced wrinkles under the lens, flal, with seam-like 

 sutures, not in the least impressed. Latter 4 whorls approaching 

 equality in diameter, subregularly and rather strongly costate (at 

 least the lower two whorls), the last one with ahout 27 (22 to 30) 

 ribs, which do not split or double on the base, although sometimes 

 there are some riblets intercalated there. 



Aperture about one-third the shell's length, oblong or rounded, 

 obliquely truncate above, liver-brown within. Peristome white, re- 

 flexed, the outer edge sharp and somewhat recurved, inner edge built 

 far forward, especially below, beveled outwardly ; parietal callus 

 either very thin or thick. Axial fold variable in prominence ; par- 

 ietal lamella very strong, rather long. Axis perforate, with a rather 

 short rima. 



Length 29, diam. 11^; alt. of aperture 11 mill. 



Length 33, diam. 11 ; alt. of aperture 11 mill. 



Length 23^, diam. 11 ; alt. of aperture 9 mill. 



Bahamas : Eleuthera (Krebs and others'). 



C. eleuthera P. and V., P. A. N. S., 1896, p. 333, pi. 11, f. 19, 

 20. Pupa gubernatoria var. /? CROSSE, J. de C., 1869, p. 186; 

 1870, p. 106, pi. 2, f. 4 (upper figure). 



This species is closely allied to C. agassizi Dall and C- guberna- 

 torium Crosse, of the island of New Providence. It has more re- 

 mote resemblance to C. sarcostomum P. and V. of Little Inagua. 



From C. agassizi it differs in never having the parietal callus 

 raised in a strong ridge making the peristome continuous ; the ribs 

 are less sharp and narrow, etc. C. gubernatorium has a proportion- 

 ally very large mouth, less thickened lip, finer riblets or none, the 

 parietal tooth is shorter, and the surface glossy ; moreover, while 

 nearly white examples occur, it is generally much variegated. There 

 can be no doubt of the close relationship of the three species, but 

 judging from a series of 25 examples of C. eleutherce, a good series of 

 C. gubernatorium and author's examples of C. agassizi, they are spe- 

 cifically distinct. 



A pair of specimens of C. eleutherce before us (from Krebs) are 

 considerably streaked with brown, otherwise typical. Another spec- 

 imen, received from Mr. Van Nostrand, is very small, alt. 18, diam. 

 8 mill., and somewhat maculated. The costulation extends further 

 up, and the peristome is not thickened. This probably represents a 

 subspecies or local race. 



