DISTRIBUTION OF THE FAUNAS. 173 



cording as they are found on different continents. Thus, 

 the monkeys of America, have flat and widely separated 

 nostrils, thirty-six teeth, and generally a long, prehensile 

 tail. The monkeys of the old world, on the contrary, 

 have nostrils close together, only thirty-two teeth, and not 

 one of them has a prehensile tail. 



436. But these differences, however important they may 

 appear at first glance, are subordinate to more important 

 characters, which establish a certain general affinity between 

 all the faunas of the tropics. Such, for example, is the fact 

 that the quadrumana are limited, on all the continents, to 

 the warmest regions ; and never, or but rarely, penetrate into 

 the temperate zone. This distribution is a natural conse- 

 quence of the distribution of the palms ; for as these trees, 

 which constitute the ruling feature of the flora of the trop- 

 ics, furnish, to a great extent, the food of the monkeys on 

 the two continents, we have only to trace the limits of the 

 extent of the palms, to have a pretty accurate indication of 

 the tropical faunas on all three continents. 



437. Several well-marked faunas may be distinguished 

 in the tropical part of the American continent, namely : 



1. The fauna of Brazil, characterized by its gigantic 

 reptiles, its monkeys, its Edentata, its tapir, its humming- 

 birds, and its astonishing variety of insects. 



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 Mex- 

 ico. This is especially characterized by its marine ani- 

 mals, among which the Manatee is particularly remarkable ; 

 an infinite variety of singular fishes, embracing a large 

 number of Plectognaths ; also Mollusks, and Radiata of 



15* 



