LAND SNAILS. 
159 
Vertigo edentula —-{the Toothless Whorl Shell) 
(PI. X., fig. 101).—The shell is dextral, cylin¬ 
drical, with five or six rounded whorls, which are 
slightly transversely striated; the third whorl 
is the largest; the aperture is semicircular and 
toothless, with the peristome very slightly re¬ 
flected ; the colour is brown or horn, with the 
peristome paler; the length is one-tenth of an 
inch. 
An elongated variety has seven or occasionally 
eight whorls, and attains the maximum length 
of one and a half lines. 
The typical form is generally found under 
stones and on rocks; the variety inhabits moister 
places; both, however, occur in woods, on the 
fallen leaves of trees in the winter and autumn; 
in the summer frequenting the under fronds of 
Aspidium jUix-mas and other ferns. 
This elegant little mollusk presents a grotesque 
appearance when crawling, for the shell is car¬ 
ried in a singularly erect position. 
Vertigo minutissima —(PL X., fig. 100).—As 
the specific name implies, this is a tiny shell, and 
is not a line in length; it is nearly cylindrical, 
with five rounded whorls, which increase sud¬ 
denly to the third, and then continue nearly of 
the same size, ornamented with acute oblique 
transverse striations. It resembles V. edentula 
in the aperture and in the absence of teeth, but 
