250 
LAND AND FRESH WATER SHELLS. 
Vertigo sexclentata.—Found by Mr. Colley with 
the last, and also by him in a similar situation a 
very short distance from Plymouth. 
Planorbis vortex_Common in pools and 
streams. 
% 
Planorbis albus.—Common in pools attached to 
plants and stones. 
Planorbis imbricatus_Rather local. In a 
standing pool near my residence I find them in 
plenty attached to plants. 
Planorbis spirorbis. Found by Mr. Colley in 
pools. Rare. 
Planorbis complanatus. In slow rivers. Con¬ 
fined according to Dr. Turt»n, to Suffolk and 
Devon. 
* Planorbis rhombeus.—In slow streams near 
Torquay. 
Limneus pereger.— Very common in pools, 
streams, and rivers. 
Limneus fossarius.—Rather common in streams, 
and pools. 
Physa fontinalis.-Not common in ponds, 
streams, and rivers, attached to stones, sticks, and 
other objects. 
Paludina stagnorum.—Very rare in pools and 
streams. I have never procured more than two 
specimens. 
Ancylus fluviatilis.—Common on stones and 
plants, in pools, streams, and rivers. 
Ancylus lacustris.—Found rarely on aquatic 
plants. 
4 species of this division of the Molluscs seem to 
be limited to this district. Observations on their 
geography, &c. occur in the next chapter. 
