RANGES OF BIRDS 239 



have enumerated, leaving only seventeen, of which at 

 least two-thirds are represented in the Nearctic region by 

 very closely allied species. Of the half-dozen species 

 which may be said to belong especially to the eastern 

 Polar region, every one is represented by a species in the 

 western Polar region belonging to the same genus. 



The following species range from Scandinavia east- 

 wards as far as the watershed between the Yenesei and 

 the Lena. The proportionate length of this list shows 

 that this boundary is almost as important a one as Bering's 

 Strait, especially when we consider that several enu- 

 merated in the second list cross over into Alaska. On the 

 other hand, we must not forget that our knowledge of the 

 birds of the country east of the Yenesei is very limited : 



Rough-legged Buzzard. Redstart. 



Hooded Crow. Willow-warbler. 



Jackdaw. Sedge-warbler. 



House Sparrow. Capercailzie. 



Northern Bullfinch. Black Grouse. 



Tree Pipit. Golden Plover. 



White Wagtail. Dotterel. 



Fieldfare. Ringed Plover. 



Redwing. Little Stint. 



The dotterel and the Little stint are the only species 

 in this list of which it can be said that their principal 

 breeding-grounds are north of the Arctic circle. The 

 nearest relations of the former species are undoubtedly 

 to be found in the southern Palsearctic region, whilst the 

 genus to which the latter belongs is well represented in 

 the Polar regions of both continents. 



Two species only appear to range from Scandinavia 

 eastwards as far as the valley of the Ob, but do not cross 

 the watershed into the valley of the Yenesei : 



Rook. Yellowhammer. 



The Ural Mountains, although they are the boundary 

 between political Europe and Asia, are by no means so 



