GRl'lATI'.k ANTIIJ.KS 



351 



Land Mollusca of the Greater Antilles. 



The Virgin Is., witii St. Croix, Aiiguillii, and the St. ]5ar- 

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

 related to Torto Rico, while Guadeloupe and all the islands to the 

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

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

 Montserrat may be regarded as intermediate between the two 

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

 Plafjloptycha and one Thelidomus, while St. Croix has two sub- 



