CLASSIFICATION OF THE WEST INDIAN ISLANDS 23 



The Caribbean chain in the northern half of its extent 

 consists of a double row of islands. The inner circle, 

 which more completely spans the distance between the 

 Great Antilles and South America, is the main chain, and 

 the outer circle is made up of secondary and dependent 

 features. 



Those of the main chain, including the islands of Saba, 

 St. Eustatius, St. Christopher, Nevis, Montserrat, Guad- 

 eloupe, Dominica, Martinique, St. Lucia, St. Vincent, Gren- 

 adines, Grenada, are volcanic heaps, of weird insular 

 forms, rising precipitously above the sea, attaining a height 

 of 4450 feet in Martinique, clad to the very top in vege- 

 tation, and usually clouded in mist. They are composed 

 entirely of old volcanic material, and from the richness 

 of their vegetation and the blackness of their rock present 

 a dark and restful landscape even under the tropical sun. 

 The outer circlet of islands, including Sombrero, Anguilla, 

 St. Martin, St. Bartholomew, Barbuda, Antigua, Desirade, 

 and Maria Galante, with the exception of Antigua, which 

 is partially volcanic, are islets of white limestone and coral- 

 reef rock, rising nowhere over two hundred feet above 

 the sea, and resembling in color the Bahamas. They rise 

 from a submerged slope extending oceanward from the 

 inner chain. 



The fourth type of tropical American islands borders 

 the north coast of South America, and includes the islands 

 of Tobago, Trinidad, Margarita, Blanca, Las Eoques, 

 Buen Ayre, Curacao, and other small islands. These were 

 once portions of the South American continent, and have 

 been severed from the mother-land by the corrosive effects 

 of the equatorial currents which here break into the Carib- 

 bean. Barbados perhaps is related to the latter group, but 

 it has a peculiar construction which justifies placing it in 

 a class by itself. In remote geologic ages it was probably 

 the end of a peninsula projecting from the South Ameri- 

 can mainland. 



The fifth and last class of West Indies consists of coral 



