300 CYLICHNA. 



almost perfectly horizontal, so that the whole top of the body-whorl 

 and the upper corner of the mouth are on the same level ; in the 

 center is a minute closed pore. Inner lip ; there is a thin narrow 

 glaze which thickens and expands in front : it is not expanded on 

 the top. Pillar is short, slightly oblique and twisted, with a strong- 

 ish defined tooth, in front of which it is rather abruptly truncate. 

 Alt. 0-156 in. ; diam. 0'066. Mouth, breadth at same place, 0'014 

 inch. (Wats.}. 



North of Culebra Island, West Indies, 390 fins. 



Cylichna discus WATS., Challenger Gastr., p. 664, pi. 49, f. 10. 



Oylichna protracta (Gould) is very like this in front, but rises 

 much higher above. Cylichna cylindracea (Pennant), is slightly 

 slimmer or narrower in proportion to length, has the body-whorl a 

 little smaller, and the mouth slightly broader, lacks the slight poste- 

 rior narrowing, and is squarely truncate behind, while here the shell 

 is rounded. The Challenger species, too, quite wants the very 

 peculiar form of the upper corner of the mouth which is character- 

 istic of Cylichna cylindracea. Cylichna alba (Brown), of the same 

 size, is rounder and less cylindrical, being more attenuated above 

 especially ; the mouth is extended above the top of the shell ; the 

 top of the body-whorl is more oblique and less truncated. (Wats.). 



C. AUBERI Orbigny. PL 41, figs. 21, 22. 



Shell ovate cylindrical, obliquely truncated at the ends, thin, 

 pellucid, white, smooth, delicately spirally striated below ; spire im- 

 mersed, replaced by an imperforate depression ; aperture narrow, 

 straight, dilated below. Alt. 3, diam. 2 mill. (Orb.). 



Cuba. 



Bulla auberii ORB., Moll. Cuba i, p. 127, pi. 4 bis, f. 5-8. 

 Cylichna auberi DALL, Blake Rep., p. 55 ; Cat. Mar. Moll. S.-E U. 

 a, p. 84. 



C. KREBSII Morch. Unfigured. 



Shell short, cylindrical, regularly spirally striated, the growth- 

 stride well developed. Lip a little produced above. Spire imper- 

 forate, covered by a thin callus ; columella strongly angulate, as in 

 Hamiuea succinea Couth. Alt. 8, diam. 4 mill. (Morch). 



St. Barts ; St. Martins; Anguilla (Krebs). 



