iy! LIMN4IDA. 
Sub-genits—BATHYOMPHALUS Agassiz. 
11. P. CONTORTUS (twésted up) Linné. Pl. VI., f. 11. 
Flat above, very convex below, dull brown ; zv/o7/s 8, compressed; 
suture deep; mouth crescent-shaped ; zzbilicus deep. A. 2 mm. 
B. 5 mm. 
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. Generally 
distributed throughout the British Isles. 
An individual which I found near Manchester measures 
6 mm. in diameter. 
Var. I. dlbida ( Jeff:). Whitish. 
Var. II. minor (Taylor). Diameter 3 mm. 
Subfamily.—PHYSIN®. 
Genus.—APLEXA Leming. 
[=Puysa Lamarck]. 
Sinistral, sub-oval, sfz7e produced. 
A. HYPNORUM (frequenting the moss Hypnum) Linné. P\.V1., 213. 
Sinistral, spindle-shaped, thin, highly glossy, semi-transparent, 
dark reddish horn-colour ; zwor/s 6—7. A. 12mm. B. 43 mm. 
This pretty little shell is found in ponds and ditches, 
at intervals, throughout the British Isles, as far north as 
Skye, but it is not a common species. 
Its frequent association with Z. glabra and P. spirorbis 
has been pointed out by Mr. W. Nelson, in an interesting 
note in the Journal of Conchology, vol. III, p. 115. The 
particular cause of their mutual attraction is not at 
