DISPERSAL BY INIAN. 189 



all ages, a white variety apparently predominating. 

 Mrs. Dyer of Swansea, who is familiar with the species, 

 as Mr. Gude tells me, saw the creatures still living on 

 the sandhills on last visiting their habitat in 1884. 

 The original immigrants, it seems, as Mr. Rimmer re- 

 marks , did not long survive, " the sudden change, per- 

 haps, injuriously affecting their delicate constitution ; " 

 evidently, however, they left behind them a progeny, 

 which, being born in the new home, took more kindly 

 to the place.' Similarly, as stated by Bourguignat, a 

 large number of Helix lactea from Valencia died during 

 the second winter at Castel-Roussillon, but some more 

 vigorous individuals born in the new locality appear to 

 have survived for some time ; finally, in this case, how- 

 ever, all perished.'- In i860, a son of Dr. Lukis, while 

 staying in Jersey, where H, pisana is abundant, some- 

 times covering the thistles,'^ collected a number and 

 carried them to Guernsey, establishing two colonies 

 there, one at Vazon Bay and the other at Vale Castle, 

 and sending a few to his sister, Mrs. Coliings of Sark, 

 who turned them out in that island " on the right bank 

 going down to the Port du Moulin." In 1877, Mrs. 

 Coliings reported, however, that none had been seen in 

 Sark for some years ; for a few years a shell or por- 

 tions of a shell had occasionally been found near a stone 



' R. Rimmer, "Quart. Journ. Conch.," i. p. 267; and see his 

 " Land and Fresh-water Shells,'' 1880, p. 133. 



' M. J. R. Bourguignat, " Mollusques nouveaux, litigieux, ou 

 peu connus," 1867, p. 234. 



' " British Conchology," i. (1862), p. 209. 



