XI 



GREATER ANTILLES 



351 



Land Mollusca of the Greater Antilles 



The Virgin Is., with St. Croix, Anguilla, and the St. Bar- 

 tholomew group (all of which are non-volcanic islands), are 

 related to Porto Rico, while Gaudeloupe and all the islands to the 

 south, up to Grenada (all of which are volcanic), show marked 

 traces of S. American influence. St. Kitt's, Antigua, and 

 Montserrat may be regarded as intermediate between the two 

 groups. St. Thomas, St. John, and Tortola have each one 



