58 HELICIDZ. 
from Manchester, on the borders of Cheshire, both it 
and its variety are not uncommon under stones, and 
along canal banks among the roots of grass in the same 
neighbourhood. 
Var. vitrina. Transparent, greenish white. 
9. Z. cRYSTALLINUS (crystalline). 
Depressed above, more convex below, thin transparent 
pearly white; whorls five, compressed ; mouth semi-lunar ; 
umbilicus exceedingly small; diameter one-eighth of an inch. 
The iridescent appearance and symmetrical form 
of this little shell cause us to regret that it is one of 
the smaller instead of the larger members of the genus. 
It is easily identified from its colour and the com- 
pressed appearance of the whorls, but especially by its 
umbilicus, which is so small that a pin of moderate 
size will hardly enter. 
It is common everywhere in moist sheltered situa- 
tions. 
Var. complanata. Nearly flat on both sides, the 
last whorl larger. 
10. Z. rotvus (tawny). 
Pyramidal, thin, glossy, of a clear semi-transparent 
horn-colour; whorls five and a half, cylindrical; mouth 
narrow ; wmbilicus merely a slight indent, only found on 
adult specimens; diameter one-tenth of an inch. 
