INLAND MOLLUSCA OF SOMERSET. 135 



Eack., Trans. Lin. Soc, vol. vlii., p. 60. The typical 

 calyculata is common in a pond on Clevedon liill, not far 

 from tlie Royal Hotel. 



Genus Pisidiüm. Pfeiffer. 



P. obtusale, Pfeiffer. In a ditcli near the Pill, Clevedon, 

 and also in the pond witli the last. The more swollen 

 forms of P. pusillum are constantly mistaken for this 

 species. The Clevedon shells have been examined by Mr. 

 Jenyns. 



P. pusillum, Turton. Teilina pusilla, Dillwyn's Cat. of 

 Kecent Shells. Common in grassy ditches, ponds, and 

 rhines. We have taken it of very large size in the moor 

 that Stretches from Clevedon towards Portishead. 



P. cinereum, Alder. A few specimens taken in Kenn 

 Moor are considered by Mr. Alder to belong to the more 

 ventricose variety of this species. Mr. Clark has met with 

 it at Bath. 



P. nitidum, Jenyns. In a large pond by the side of the 

 railway, at the third (?) bridge from Clevedon. 



P. pulcheUu77i, Jenyns. In the larger and clearer of the 

 z'hines, not uncommon. Fine in West Mead Rhine, Yatton. 



P. Ilenslowianum, Sheppard. A specimen or two in the 

 " river," at Clevedon. This and the last must be united, 

 as has already been suggested by Messrs. Jenyns and 

 Jeffreys. "We have met with specimens in Company, some 

 with the "lamelliform projection" well developed, some 

 with scarcely pcrceptible traces of it, and some again with 

 the umbones prcscntiug no irrcgularity. These specimens 

 agrecd in all other respects. 



P. amnicum, Müller. Teilina amnica, Mat. and Eack., 

 Trans. Lin. Soc, vol. viii., p. 60. In rivers and streams, 

 widcly distributed througbout the county. 



