54 HELICID^. 



3. Z. GLABEK (smooth). 



Convex above and below, very glossy, semi-transparent, 

 pale horn-colour, only slightly marked with white below ; 

 spire raised, and produced to a point; outline of mouth 

 forming about three-quarters of an almost symmetrical 

 circle ; whorls five to six ; umbilicus deep, but not disclosing 

 so much of the last whorl as that of Z. cellarius ; diameter 

 slightly more than three-eighths of an inch. 



This shell, which is distributed widely throughout 

 England, and has also been found in Wales and the 

 south of Scotland, is local. 



Its discovery in this country is due to Mr. Thomas 

 Rogers, of Manchester, who first noticed it in 1870. 



It is likely to be mistaken for Z. cellarius, from 

 which it differs in the following respects : 



(1.) It measures less in diameter. 



(2.) It measures more in height in proportion to its 

 diameter. 



(3.) The spire is raised by a slight inclination to a 

 point. 



(4.) The outline of the mouth is nearly circular in- 

 stead of oval. 



(5.) The umbilicus does not disclose the penultimate 

 whorl, as is the case with Z. cellarius. 



(6.) When the two shells are viewed directly towards 

 the mouth, the interior of the mouth of Z. cellarius 



