CUBA JAMAICA 



347 



sist mainly of Hdicina proper (58 sp.), which here attains hy 

 far its finest development in point of size and heauty, and of 

 EutrochatcUd (21 sp.), which is peculiar to the three great islands 

 (Jamaica 6 sp., San Domingo 6 sp.) 



The Bahamas, consisting in all of more than 700 islands, are 

 very imperfectly known, but appear to be related partly to Cuba, 

 partly to San Domingo, from each of which they are separated 

 by a narrow channel of very deep water. They are certainly 

 not rich in the characteristic groups of the Greater Antilles. 

 The principal forms of Helix are Flagioptycha (0 sp.), common 

 with San Domingo, and Hemitrochus (6 sp.), common with Cuba. 



Fig. 229. — Characteristic 

 Cuban Helices. A, Poly- 

 dontes imperator Montf. 

 B, Caracolus rostrata 

 Pfr. C, Polymita vms- 

 carv.m Lea. 



StrojjJrm is exceedingly abundant, but Cylindrella, Macroceramus, 

 and Giandina have but few species. There are a few species of 

 Ctenopoma, Ghondropoma, and Cistula, while a single Schasicheila 

 (absent from the rest of the sub -region) forms a link with 

 Mexico. 



Southern Florida, with one or two species each of Hemitrochus, 

 Gylindrella, Macroceramus, Strophia, Ctcnoiooma, and Chondropoma, 

 belongs to this province. 



(h) Jamaica. — The land Mollusca of Jamaica are, in point of 

 numbers and variety, quite unequalled in the world. There are 

 in all as many as 56 genera and more than 440 species, the 

 latter being nearly all peculiar. The principal features are the 



