LAND SNAILS. 
143 
lias the spire quite flattened. The diameter of 
the shell is one-third of an inch. 
This snail inhabits a great variety of situations, 
—beneath stones in damp woods, on rocks, among 
fallen leaves, and shows a predilection for decay¬ 
ing wood. 
Helix rupestris —{the Wall Snail) (Pi. VII., 
fig. 46)—is one of our minute species, passing 
its days between the bricks and stones at the 
tops of old walls and ruins of castles, on the 
rocks, and under debris on hill-sides, usually 
in dry, lofty, and exposed situations, and at¬ 
taches itself more markedly to limestone rock, 
though I have found it on sandstones in the 
North of Ireland; on the quartzose conglomerate 
of Bristol; but certainly very abundantly on the 
limestone of the oolitic rocks of the West of 
England, among the debris of the quarries and 
on the bare rock surfaces. It is rare in Ireland. 
The shell is somewhat conical, of a blackish- 
brown colour, slightly glossy, marked trans¬ 
versely with strong, oblique curved striee; the 
whorls are five in number, rounded, separated 
from one another by a deep suture; the aperture 
is nearly circular ; umbilicus very large; the 
diameter of the shell is one-tenth of an inch. 
A well-known synonym for this species is H. 
umbilicatus , suggested by the open umbilicus, 
which so markedly characterizes it. 
