206 GEOGRAPHICAL DISTRIBUTION OF ANIMALS. 



2. The fauna of the western slope of the Andes, com- 

 prising Chili and Peru; and distinguished by its Llamas, 

 vicunas, and birds, which differ from those of the basin of 

 the Amazon, as also do the insects and mollusks. 



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

 This is especially characterized by its marine animals, among 

 which the Manatee is particularly remarkable ; an infinite 

 variety of singular fishes, embracing a large number of 

 Plectognaths ; also Mollusks, and Radiata of peculiar species. 

 It is in this zone that the Pentacrinus caput-medusa is found, 

 the only representative, in the existing creation, of a family so 

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



The limits of the fauna of Central America cannot yet be 

 well defined, from want of sufficient knowledge of the ani- 

 mals which inhabit those regions. 



438. The tropical zone of Africa is distinguished by a 

 striking uniformity in the distribution of the animals, which 

 corresponds 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 

 hippopotamus 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 conditions of vegetation very similar, over wide 

 countries. Some 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 elephant, the crocodile of the 

 Nile, a vast number of Antelopes, and especially two species 

 of Orang-outang, the Chimpanzee and the Engeena, a large 

 and remarkable animal, only recently described. The fishes 

 of the Nile have a tropical character, as well as the animals 



