166 THE GEOGRAPHY OF MAMMALS 



Lagomys, the " Pika," or Tailless Hare, which is found in 

 the higher mountain ranges of both the Old and the New 

 Worlds. 



The Carnivora do not present many features of special 

 interest. Two srenera — Mustela. containing the Weasels, 

 and Galo, the Glutton, have much the same circumpolar 

 distribution as has been already remarked on in the case 

 of the Deer and the Lemming. 



The number of genera of Insectivora and Chiroptera in 

 the Canadian Sub-region is insignificant, and they are of no 

 interest from a distributional point of view. 



Viewing the fauna of the Canadian Sub-region as a 

 whole, it will thus be seen that its greatest point of interest 

 is its resemblance to that of the more northerly parts of 

 the Old World. This, of course, may be easily accounted 

 for when we recollect that the sea of Behring Straits is 

 quite shallow, and in places not more than about 20 miles 

 in breadth. There can be no doubt that there was a land- 

 connection between Siberia and Alaska in comparatively 

 recent geological times, and that this has resulted in the 

 commingling of the faunas of the northern parts of these 

 two Regions, to a considerable extent. This land-bridge 

 must have existed so recently that there has not yet been 

 even time for, in some cases, the animals to become 

 differentiated into appreciable species, as in the cases for 

 example, of the reindeer and elk. 



Below will be found a summary of the genera of the 

 Canadian Sub-region, forty in number, which are divided 

 into five categories much in the same fashion as has been 

 done in the previous articles, namely : — 



1. Endemic — those found only in the Canadian Sub- 

 resfion. 



