DISTRIBUTION OF THE FAUNAS. 169 



the tunny. All classes of the Mollusks are represented ; 

 though the cephalopods are less numerous than in the torrid 

 zone. There is an infinite number of Articulata of every 

 type, as well as numerous Polyps, though the corals proper 

 do not yet appear abundantly. 



429. On each of the two continents of Europe and Amer- 

 ica, there is a certain number of species which extend from 

 one extreme of the temperate zone to the other. Such, for 

 example, are the deer, the bison, the cougar, the flying-squir- 

 rel, numerous birds of prey, several tortoises, and the rattle- 

 snake, in America. In Europe, the brown bear, wolf, 

 swallow, and many birds of prey. Some species have a 

 still wider range, like the ermine, which is found from 

 Bhering's Straits to the Himalaya Mountains, that is to say, 

 from the coldest regions of the arctic zone, to the southern 

 confines of the temperate zone. It is the same with the 

 muskrat, which is found from the mouth of Mackenzie's 

 River to Florida. The field-mouse has an equal range in 

 Europe. Other species, on the contrary, are limited to one 

 region. The Canadian elk is confined to the northern por- 

 tion ; and, on the other hand, 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 



* The types which are peculiar to temperate America, and are not found 

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

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

 cristata), which replaces the Mygale of the Old World ; several genera 

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

 America 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. 



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