ZONITES. 55 
is seen to be more interrupted by the penultimate 
whorl. 
(7.) It has less white below, and is altogether slightly 
more smooth and transparent. 
In shape it more nearly resembles Z. alliarius, but 
its size is sufficient to prevent its being mistaken for 
that species. 
Mr. Rogers tells me that when the animal is within 
the shell it may easily be recognized by the abrupt 
termination of the colour of the mantle, which is dis- 
tinctly visible through the transparent shell. 
A, Z. nivivupvs (slightly glossy). 
Compressed, thin, only slightly glossy, whitish under- 
neath; whorls five, convex; spire slightly raised; sutwre 
rather deep; mouth round, except where interrupted by the 
last whorl; wmbilicus very broad and deep; diameter be- 
tween a quarter and three-eighths of an inch. 
This shell is widely distributed, and, like the rest of 
the genus, frequents moist places under stones and in 
woods. 
It may be distinguished from Z. cellarius by its 
smaller size and its much larger umbilicus. It has, 
moreover, one whorl less, and is not nearly so glossy. 
Var. I. nitens. Smaller and lighter, last whorl very 
large. 
