﻿290 Mr. E. Hartert on the Birds of 



on Curacao, and on the east coast of Bonaire ; while Aruba, 

 for almost its entire length on the leeward side, is skirted by 

 a coral-reef, inside of which is a calm and beautiful lagoon. 



The interior parts of the islands consist of sedimentary 

 rocks, in several places pierced by volcanic rocks, while on 

 Aruba grey granite is said to predominate, and many quartz 

 veins are found, containing a considerable amount of gold. 

 Deposits of phosphate are distributed over the islands (cf. 

 Blackburn, ' Aruba-Phosphate/ p. 5). 



The geologist, Professor K. Martin, who explored the 

 islands in 1885, came to the conclusion that they were 

 formerly atolls; but his conclusion is questionable, for a 

 similar coralline belt is found on many Wesc-Indian islands. 



The same naturalist (cf. 'Bericht iiber eine Reise nach 

 Niederlandisch Westindien/ 1887) came to the conclusion 

 " that the islands of Aruba and Curacao (the materials col- 

 lected on Bonaire were too incomplete for any conclusions) 

 are zoologically closely allied to the continent of South 

 America, and, on the other hand, that the fauna of both 

 differs in many points/' Both these conclusions of the 

 learned author — whose excellent book was of much service 

 to me — must, however, be qualified in some way, although 

 they are not altogether wrong. It is true that the greater 

 part of the fauna is similar to that of the northern parts of 

 Venezuela, but there are likewise a great many forms of 

 West-Indian origin, and this not only among the birds, but 

 also among the reptiles, and, according to Dr. Kobelt, very 

 strikingly among the land-shells. The ornis and the whole 

 fauna of the three islands are generally similar, although 

 there are some remarkable differences. 



The idea that the fauna of these islands is the same as 

 that of the adjacent parts of the continent, together with 

 their barren and rocky appearance from the sea, and the 

 exaggerated reports of their heat and dryness, are perhaps 

 the reasons why the ornis of Aruba and Bonaire remained 

 unexplored until my researches, and why that of Curacao 

 has only quite recently, and incompletely, been explored. 



No tropical forest is found on the islands, but trees of 

 [2] 



