246 THE DISPERSAL OF SHELLS. 



Helix cartusiana Miill. This snail (which, 

 according to Mr. Jeffreys, is known to inhabit the 

 whole of France, the Rhine district, South Germany, 

 Switzerland, Dalmatia, Italy, and Greece, and has been 

 recorded as a Siberian species) was detected in Britain 

 in 1 8 14. In this country, however, though plentiful 

 where it occurs, it has a very restricted range, being 

 confined, apparently, to the neighbourhood of the sea, 

 along the coasts of Kent and Sussex; and Jeffreys, it 

 appears, at one time thought that it had been naturalized 

 here by an importation from the opposite coast of 

 France ; but at the time of the publication of the 

 " British Conchology " he regarded it as " clearly in- 

 digenous." ' A colony, known at one time on the east 

 moors near Cardiff on a small patch of raised ground 

 covered with a luxuriant growth of ballast plants, was 

 almost certainly introduced with ballast ; but the 

 creature has now disappeared from that locality .- 



Helix PISANA Miill. Extremely local as a British 

 species, this snail is distributed at random in a few 

 widely separated places on or near the coast ; in the 

 Channel Isles, it occurs in Jersey, in the south of 

 England in Cornwall, in Wales in Pembrokeshire, and 

 in Ireland in Meath and Dublin counties ; intentionally 

 introduced colonies are known to exist near Swansea, 

 in Guernsey, and possibly in other places. The 

 creature's foreign distribution, Mr, Rimmer^ has 



* Jeffreys, " Trans. Lin. Soc," xvi. (1833), p. 509; " British Con- 

 chology," i. (1862), pp. 48-9, 193-4. 



"■ F. W. Wotton, •' Journ. of Conch.," v. (1886), 



