THE NEARCTIC REGION 165 



Nemorliiedus, of the mountains of Asia, which occurs in 

 Japan (N. crispus), but of which the best-known form is 

 commonly designated the "Serow" by the sportsmen of 

 the Himalayas. There are also no less than four genera 

 found in the Old World, and also in the Canadian Sub- 

 region, which do not extend further south. These are 

 Cervus, containing the Wapiti (C. canadensis), closely allied 

 to the Red Deer of the Old World ; the Cariboo (Rangifer), 

 which cannot be distinguished from the Reindeer of the 

 northern part of the Palsearctic Region: and the Moose 

 (Alces machlis), which has the same distribution as the 

 Reindeer, but is known in Europe under the name of " Elk." 

 Besides these, there are two Canadian genera of this order 

 which are found in other Sub-regions as well as in the Old 

 World, namely, the Bison (Bison) and the Sheep (Ovis). 

 The Bison, of which the American representative is the so- 

 called buffalo (now, alas ! nearly extinct), is closely allied 

 to the European Bison, still found in certain parts of the 

 Old World ; while the Big-horn Sheep (Ovis canadensis) is 

 a representative of the Wild Sheep, which are extensively 

 distributed in the Palsearctic Region. The number of 

 genera of Rodents of the Canadian Sub-region amounts in 

 all to eighteen, of which three are peculiar. One of these 

 is Haplodon, to which allusion has already been made ; 

 the others are Phenacomys, a small genus of rats, and 

 Erethizon, which contains only the Tree-porcupine of the 

 Canadian forests. Among the members of this order, too, 

 we find three genera common to this Sub-region and the 

 Old World, which do not extend further south. These 

 are My odes (M. obesus), which is represented in Europe by 

 an allied species, the well-known Lemming of Scandinavia ; 

 Cuniculus, a form nearly allied to the Lemming; and 



