LAND AND FRESH- WATER SHELLS. 95 



verse ridges ; on the contrary, he says, " in marshy places, we as 

 constantly find the second variety with its striae and epidermis, and 

 never without them." Now, in Suffolk, on the banks of the river 

 Waveney, I have found none but the striated variety, which Tur- 

 ton also says he finds in marshy places; but here, on the banks of 

 the Carlton brook, (which is bounded, on both sides, by low, flat 

 meadows), out of more than one hundred specimens, I have not one 

 with the least appearance of striae upon it ; so that a dry or moist 

 situation cannot be the cause of the difference ; I am, therefore, 

 inclined, upon present evidence, to suppose they may be two distinct 

 species, though in every other respect their resemblance is great. 



BuLiMus LUBRicus, — In abundance amongst dead leaves. 

 SucciNEA AMPHIBIA, S. OBLONGA, — In the Carlton brook and River 



Sence. 

 I am inclined to suppose the above are only varieties of one species. 



They are almost as various in their form as individuals of Limneus 



pereger. 



Carychium minimum, — In great abundance on the dead leaves of 

 the sedge. 

 I have, also, sometimes found it among the matted roots of Bryum 

 ligulatum, in woods and on banks. 



Vertigo Pygmoea, — This minute, but strongly-formed shell, is 

 found, in considerable abundance, with the latter. 



Planorbis corneus, — River Sence ; P. fontanus, — Pond in 

 Bosworth Park; P. carinatus, P. marginatus, P. vor- 

 tex, P. coNTORTus, p. ALBUS, P. spiRORBis, — Carlton 

 brook. 



Limneus auricularius, — River Sence; L. pereger, L. stagna- 

 Lis, — In ponds ; L. fossarius, — In ditches ; L. palustris, 

 — River Sence ; L. elongatus, — In ponds. 



Physa fontinalis, p. hypnorum, — Carlton brook. 



Valvata obtusa, — Carlton brook. 



Paludina achatina, — Ashby Canal ; P. impura, — Carlton brook. 



Neritina fluviatilis, — Carlton brook. 



Ancylus fluviatilis, a. lacustris, — Carlton brook. 



All the above shells, with the exception of Helix trochus and 

 pygmaea, Planorbis corneus and spirorbis, and Ancylus lacustris, I 

 have met with in the neighbourhood of Rugby, about twenty-five 

 miles south of this place, together with the following, which I have 

 not yet discovered here. Cyclas rivicola, — Oxford Canal ; Cyclas 



