CHAP. XIV.] THE NEOTROPICAL REGION. 29 



birds witli silky plumage peculiar to the Amazon valley. They 

 are often kept in houses, where they get very tame and affec- 

 tionate ; and they are useful in catching flies and other house 

 insects, which they do with great perseverance and dexterity. 



Islands of TrojJical South America. 



These are few in number, and, with one exception, not of 

 much interest. Such islands as Trinidad and Sta. Catherina 

 form parts of South America, and have no peculiar groups of 

 animals. The small islands of Fernando Xoronha, Trinidad, 

 and Martin Yaz, off the coast of Brazil, are the only Atlantic 

 islands somewhat remote from land ; while the Galapagos Archi- 

 pelago in the Pacific is the only group whose productions have been 

 carefully examined, or which present features of special interest. 



Galapafjos Islands. — These are situated on the equator, about 

 500 miles from the coast of Ecuador. They consist of the large 

 Albemarle island, 70 miles long ; four much smaller (18 to 25 

 miles long), named Narborough, James, Indeftitigable, and Chat- 

 ham Islands ; four smaller still (9 to 12 miles long), named 

 Abiugdon, Bindloes, Hood's, and Charles Islands. All are vol- 

 canic, and consist of fields of black basaltic lava, with great 

 numbers of extinct craters, a few which are still active. The 

 islands vary in height from 1,700 to 5,000 feet, and they all rise 

 sufficiently high to enter the region of moist currents of air, so 

 that while the lower" parts are parched and excessively sterile, 

 above 800 or 1,000 feet there is a belt of comparatively green 

 and fertile country. 



These islands are known to support 58 species of Vertebrates, 

 — 1 quadruped, 52 birds and 5 reptiles, the greater part of which 

 are found nowhere else, while a considerable number belong to 

 peculiar and very remarkable genera. We must therefore notice 

 them in some detail. 



Mammalia. — This class is represented by a mouse belonging 

 to the American genus Hcspcromys, but sliglitly different from 

 any found on the continent. A true rat {Mus), slightly dif- 

 fering from any European species, also occurs ; and as there can 

 be little doubt that this is an escape from a ship, somewhat 



