WEST INDIAN LAND-SHELLS. 303 



since our return, by an American naturalist, Mr. Bland, in a 

 paper, read before the American Philosophical Society, on 

 " The Geology and I'hysical Geography of the AYest Indies, 

 with reference to the distribution of MoUusca." It is plain 

 that of all animals, land-shells and reptiles give the surest 

 tokens of any former connection of islands, being neither able 

 to swim or fly from one to another, and very unlikely to be 

 carried by birds or currents. Judging, therefore, as he has a 

 right to do, by the similarity of the land-shells, Mr. Bland is 

 of opinion that Porto Pdco, the Virgins, and the Anguilla 

 group, once formed continuous dry land, connected with 

 Cuba, the Bahamas, and Hayti ; and that their shell-fauna 

 is of a Mexican and Central American type. The shell- 

 fauua of the islands to the south, on the contrary, from 

 Barbuda and St. Kitts down to Trinidad, is South American : 

 but of two types, one Yenezuelan, the other Guianan. It 

 seems, from Mr. Bland's researches, that there must have 

 existed once not merely an extension of the North American 

 Continent south-eastward, but that very extension of the 

 South American Continent northward, at which I have 

 hinted more than once in these pages. Moreover a fact 

 which I certainly did not expect the western side of this 

 supposed land, namely Trinidad, Tobago, Grenada, the Grena- 

 dines, St. Vincent, and St. Lucia, Have, as far as land-shells 

 are concerned, a Venezuelan fauna ; wdiile the eastern side 



