PHYSA. ae 
Var. albina. White, not uncommon. 
1l. P. contortus (twisted wp). 
Flat above, very convex below, dull brown; whorls eight, 
compressed; suture deep; mouth crescent-shaped; winbilicus 
deep. 
This is a compact-looking little shell, and when once 
seen is never confounded with any other. It is fairly 
common on weeds in ponds and ditches. 
Var. albida. Whitish. 
10, P. pmatAtus (expanded). 
Flattish above, extremely convex beneath ; whorls two 
to two and a half, dull; nearly opaque; mouth exceedingly 
expanded, and very large; suture distinct; wmbilicus 
narrow, but deep. 
This little shell was imported from America in cotton 
bales. It was first noticed by Mr. T. Rogers, of Man- 
chester, in 1869. The only two places where it has 
yet been observed to have made itself at home are the 
Bolton Canal and the Reddish Canal (between Stock- 
port and Manchester), where there are cotton mills. 
Genus IT—PHYSA. 
1. P. nypnorum (frequenting the Hypnum, a moss). 
Sinistral, spindle-shaped, thin, highly glossy, semi-trans- 
parent, dark reddish horn-colour; whorls six to seven. 
D 
