88. 
89. 
90. 
ot. 
THE MOLLUSCA OF DORSETSHIRE. 25 
P. corneus (Z.) Helix cornea, L. 
Montagu Test. Brit., p. 428. 
“ Proceedings” of Dorset Natural History and Antiquarian 
Field Club, Vol. xii., p. 103. 
Slow streams, ponds, ditches. 
The largest of the European species of Planorbis; Montagu 
describes it as plentiful in some parts of England, but that 
he had not found it further westward than in Dorset- 
shire. 
Weymouth, C. O. P. Cambridge. 
[P. glabra, Jeffreys. 
On aquatic plants in marshes, lakes, and ponds. 
A rare British shell, and occurs as early as the Upper Tertiary 
period. 
Fossil : Quaternary bed, Chesilton, Portland, Prestwich. 
There is no record of a Dorset living specimen. | 
P. parvus, Suy. P. glaber, Jef. 
This shell is local, although its range is wide. Jeffreys records 
only 20 British localities (1862). 
Portland, Quaternary deposit, cliff near the Bill, Prestwich. 
PHYSIDA. 
PHYSA, Drap., 1801. 
P. fontinalis, (Z.) Bulla fontinalis, L. 
Pulteney, p. 43, pl. 21, f. 6. Montagu, Test. Brit., Vol. i., 
p. 228. Purbeck Papers, Vol. ii., p. 46. 
On aquatic plants in streams and ditches. 
Weymouth, Damon. 
Dorchester, Fordington meadows, water-courses, J. C. M.-P. 
Chamberlaynes, Bere Regis, J. C. M.-P. 
