194 THE DISPERSAL OF SHELLS. 



at once in Mr. Binney's garden ; ' Helix hortensis from 

 the island of Martha's Vineyard, " of course introduced 

 from Europe," could not be established by Mr. J. H. 

 Thomson in his garden, the young being devoured/ it 

 was believed, by slugs, Liinax, Avion, etc. f thirty or forty 

 specimens of the same species once placed in a hedge- 

 row in this country, in the neighbourhood of Upton, 

 were never afterwards seen ;^ a large number of Helix 

 virgata from various localities turned out near Chisle- 

 hurst did not " seem to multiply,'^ and many specimens 

 of Helix cartusiana from Sandwich liberated in the same 

 neighbourhood are believed to have died out.^ 



Slugs, I suppose, have not been much dispersed inten- 

 tionally. Half a dozen Testacellce from the Isle of 

 Wight once turned out by Mr. W. Jeffery in his garden 

 appear to have been lost sight of; a single quarter- 

 grown individual, however, is said to have been detected 



' W. G. Binney, "Terrestrial air-breathing Mollusks," v. (1878), 



379- 



* With reference to this statement it may be interesting to 

 notice that in Charleston, S.C., a foreign snail, believed to be 

 Helix nejnoralis, formerly existing there in great numbers, was 

 completely exterminated by BiiHimis decoUatiis, also a foreign 

 species, at least so the elder Binney was informed on what was 

 considered good authority, but, as he admitted, the destruction of 

 the one species, though subsequent to the introduction of the 

 other, might not have had any connection with it. A. Binney, 

 "Terrestrial air-breathing Mollusks," i. (1851), p. 134. 



^ J. H. Thomson, " Journ. of Conch.," iv. (1885), p. 373. 



"• L Byerley, •' Proc. Lit. and Philos. Soc, Liverpool," 1854, 

 p. 47. 



•^ T, D. A. Cockerell, "Journ. of Conch.," iv. (1884), p. 238. 



