DISTEJIH TION OF THE FAUNAS. 379 



619. Several well-marked faunas may oe distinguished in 

 the tropical part of the American continent, namely : 



1st. The fauna of Brazil, characterized by its gigantic reptiles, 

 its monkeys, its edentata, its tapir, its humming-birds, and the 

 astonishing variety of its insects. 



2nd. The fauna of the western slope of the Andes, comprising 

 Chili and Peru, is distinguished by its llamas, vicunas, and 

 birds, which differ from those of the basin of the Amazon, as 

 also do the insects and mollusks. 



3dly. The fauna of the Antilles and the Gulf of Mexico. This 

 is especially characterized by its marine animals, among which 

 the Ma n a f us is particularly remarkable ; an infinite variety of 

 singular fishes, embracing a large number of plectognaths ; 

 also mollusca, and radiata of peculiar species. It is in this 

 zone that the Pentacri/ms caput-medusfB is found, the only 

 representative, in the existing creation, of a family so nume- 

 rous in ancient epochs, the Crinoidea with a jointed stem. 



The limits of the fauna of Central America cannot yet be 

 well defined, from a want of sufficient knowledge of the animals 

 inhabiting those regions. 



620. The tropical zone of Africa is distinguished by a 

 striking uniformity in the distribution of the animals, cor- 

 responding to the uniformity of the structure and contour of 

 that continent. Its most characteristic species are spread over 

 the whole extent of the tropics : thus, the giraffe is met with 

 from Upper Egypt to the Cape of Good Hope. The hippopo- 

 tamus is found at the same time in the Nile, the Niger, and 

 Orange River. This wide range is the more significant, as it 

 also relates to herbivorous animals, and thus supposes condi- 

 tions of vegetation very similar over wide countries. Some 



O * 



forms are nevertheless circumscribed within narrow districts ; 

 and there are marked differences between the animals of the 

 eastern and western shores. Among the remarkable species 

 of the African torrid region are the baboons, the African ele- 

 phant, the crocodile of the Nile, a vast number of antelopes, 

 and especially two species of ourang-outang, the chimpanzee 

 and t\\e Engeena, a large and remarkable animal, only recently 

 described. The fishes of the Nile have a tropical character, 

 as well as the animals of Arabia, which are more allied to 

 those of Africa than to those of Asia. 



621. The tropical fauna of Asia, comprising the two pe- 



