54 HELICIDA. 
3. Z. GLABER (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; wmbilicus 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 melination to a 
point. 
(4.) The outline of the mouth is nearly cireular 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 
