SWANTON : LAND AND FRESHWATER MOLLUSCA OF SOMERSETSHIRE. 243 



'51. Crotch, W. R. — On the recent Plants and Shells of the 

 Weston District, 1851. (A list of some forty species read before the 

 members of the Somerset Archaeological and Natural History Society, 

 at Weston-super-Mare). 



'6o. Norman, A. M. — The Inland Mollusca of Somersetshire, Proc. 

 Somerset Arched, and Nat. Hist. Soc, vol. 10, i860. 



'75, Leipnor, Adolph. — List of Land and Freshwater Mollusca of 

 the Bristol District, Proc. Bristol Nat. Soc, n.s., vol. 1, pt. 2, p. 273, 



1875- 



'77. Poulton, F. L. — British Aquatic and Freshwater Mollusca 

 obtained in the neighbourhood of Bristol, second edition, revised by 

 T. Ord, Bristol, 1877. 



'80. Rimmer, Richard. — The Land and Freshwater Shells of the 

 British Isles, London, 1880. 



'82. Cundall, J. W. — The Mollusca of Bristol and Vicinity, /. 

 Conch., vol. 3, p. 260-267, 1882. 



'84. Ponsonbv, John, F.Z.S. — A List of Shells found in the Neigh- 

 bourhood of Yeovil, J. Conch., vol. 4, p. 245, 1884. 1 



'90. Swanton, E. W. — A Day's Conchology on the Glastonbury 

 Moors, Naturalists' Gazette, vol. 2, 1890. 



'91. . A List of the Shells of the Wincanton District, Proc. 



Wincanton Field Club, third annual report, 1891. 



'94. . Vertigo edentula in Somerset, Naturalists' Journal, 



vol. 2, 1894. 



'95. . Fauna and Flora of a Somerset Village, op. cit., vol. 4, 



1895. 



Bowell, E. W. W. — Notes on the Mollusca of Hatch, co. Somer- 

 set. (In manuscript.) 



Note on Petricola pholadiformis Lam. — This shell was first noted as British 

 in 1890 {Proc. Mai. Soc, vol. 1, p. 291 ; vol. 2, p. 134, 135), and in 1896 was found 

 at Heme Bay and Shellness near Sandwich. It now flourishes on Sandwich Flats, 

 though the shells there never seem to attain anything like the size of Heme Bay 

 examples ; this may be due to the more sheltered waters of the last-named locality. 

 The shell is usually pure white in colour, but about two per cent, have the posterior 

 side stained with reddish-purple ; this staining appears to be done by the mollusc 

 itself and is not due to any external cause. About one-third of the Shellness ex- 

 amples are more or less deformed at the posterior side, which is either shortened 

 and rounded or else twisted to one side. It would be interesting to know the 

 reason of this torsion, which seldom or never occurs in Fholas Candida, a shell 

 similar in size and habitat. — J. E. Cooper. {Read before the Society, June 14, 

 i899)- 



1 Enumerates fifty-three species, including the rare Helix granulata (=serzcea). I much 

 regret the omission of Mr. Ponsonby's records, but only became aware of his paper after the 

 completion of my notes and the publication of some of them in the April number of the 

 Journal. 



