CH. II] CANADIAN SUB-REGION. 97 



confined to the sub-region. The bison so reduced in 

 numbers now-a-days is almost confined to the Rocky 

 Mountain sub-region. The prairie dog, Cynomys, a close 

 ally of the marmot, is restricted to the sub-region. Birds 

 contribute their quota toward distinguishing the sub-region 

 from those which border upon it. But they are genera 

 and not families. Among them may be. mentioned the 

 following: SaVpinctea, a wren, Poospiza, a finch, and Pe- 

 dioccetes, a grouse. 



III. Eastern or Alleghany sub-region. Mr Wallace 

 remarks that this sub-region "contains examples of all 

 that is most characteristic of Nearctic zoology." But 

 there is only one genus of Mammalia that is absolutely 

 confined to it. This is Condylura, the star-nosed mole. 

 Only 30 birds are mentioned by Wallace as peculiar to 

 the region among non-migrants. 



IV. The Subarctic or Canadian sub-region. This 

 naturally presents many features of resemblance to the 

 arctic parts of the Palsearctic region. It is charac- 

 terised for example by such forms as the glutton, reindeer 

 and elk, which pass into the Palsearctic region also. 

 The musk deer however, Ovibos, is limited to this region, 

 having apparently been a few times found outside of it in 

 the Palasarctic region. The birds though numerous are 

 not so peculiar: it upsets the current notions as to the 

 tropical habits of the humming-birds to learn that a 

 species, Selasphorus rufus, breeds in Alaska. 



B. z. 



