234 THE DISPERSAL OF SHELLS. 



Pupa CINEREA Drap. is also included, as doubtfully 

 British, in the new catalogue, "in the faint hope that its 

 claim to inclusion in the British list may be strengthened 

 by further observation." Jeffreys, in 183 1, stated that 

 a specimen had been found by Mr. Gray among the 

 rejectamenta of the Thames at Battersea, and he himself 

 had detected an imperfect specimen at the same place. 

 But, in 1840, Gray treated the species as having been 

 improperly regarded as British, stating that he had 

 introduced it into the fauna in error, a specimen having 

 been accidentally mixed by Dr. Leach with some other 

 shells collected at Battersea, and Mr. Jeffreys' record, 

 also, he thought, was probably erroneous. More re- 

 cently, however, specimens all presumably dead — two 

 of which have been identified by Mr. J. W. Taylor — are 

 reported to have been takcn^ on four occasions during 

 twelve years, near Accrington, Lancashire. Their 

 presence may most probably be attributed to man's 

 dispersal, but some naturalists think it unlikely that 

 they were thus introduced, for the locality is described as 

 " well-wooded out-of-the-way." ^ 



As already stated, there are at least six other land- 

 shells in the British list which have been regarded by 

 authors as probable or possible importations. Very 

 likely all of them are indigenous, but, be this as it may, 



' " Journ. of Conch.," vii. (1892), pp. 54-62 ; J. G. Jeffreys, "Trans. 

 Lin. Soc," xvi. (1833), p. 514 ; Gray's " Turton," (1840), p. 13 ; R. 

 Wrigglesworth, " Science Gossip," xxv. (1889), p. 281 ; and see also 

 " Naturalist," 1892, p. 336. 



