202 GEOGRAPHICAL DISTRIBUTION OF ANIMALS. 



The Canadian elk is confined to the northern portion of the 

 fauna ; while the prairie wolf, the fox-squirrel, the Bassaris, 

 and numerous birds, never leave the southern portion.* 



430. In America, as in the Old World, the temperate 

 fauna is further subdivided into several districts, which may 

 be regarded as so many zoological provinces, in each of 

 wliich there is a certain number of animals differing from 

 lliose in the others, though very closely allied. Temperate 

 America presents us with a striking example in this respect. 

 We have, on the one hand : 



1st. The fauna of the United States properly so called, on 

 this side of the Rocky Mountains. 



2d. The fauna of Oregon and California, beyond those 

 mountains. 



Though there are some animals which traverse the chain 

 of the Rocky Mountains, and are found in the prairies of 

 the ]\Iissouri as well as on the banks of the Columbia, as, 

 for example, the Rocky Mountain deer, [A/itilop'' furcifcr^) 

 yet, if we regard the whole assemblage of animals, they are 

 found to differ entirely. Thus, the rodents, part of the 

 ruminants, the insects, and all the mollusks, belong to dis- 

 tinct species. 



431. The faunas or zoological provinces of the Old World 

 which correspond to these are : 



* The types which are peculiar to temperate America, and arc not fo-and 

 in Europe, are the Opossum, several genera of Insectivora, among them 

 the shrew-mole (ScaJojJS aquaticus) and the star-nose mole, {Condylura 

 cristata,) vihxch. replaces the Mygale of the Old "World ; several genera 

 of rodents, especially the muskrat. Among the types characteristic of 

 Amorica must also be reckoned the snapping-turtle among the tortoises ; 

 the Menobranchus and Menopoma, among the Salamanders ; the Gar- 

 pike and Amia among the fishes ; and finally, among the Crustacea, the 

 Limulus Among the types which are wanting in temperate America, 

 and which are found in Europe, may be cited the horse, the wild boar, and 

 the true mouse. All the species of domestic mice which live in America 

 have been brought from the Old World. 



