298 SIBERIA IN EUROPE. CHAP. XXIII. 



unite the two together into one circumpolar region. A more 

 minute examination of the list may, however, lead us to a 

 different conclusion. It is not correct to speak of a bird 

 as an Arctic species, unless its breeding-grounds are prin- 

 cipally within the Arctic Circle. "We must, therefore, elimi- 

 nate from our list those species whose breeding-grounds are 

 principally south of the Arctic Circle, and only extend beyond 

 it at the extreme northern limit of their range. This will 

 dispose of thirty of the species we 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 eastwards 

 as far as the watershed between the Yenesay and the Lena. 

 The proportionate length of this list shows that this boundary 

 is almost as important a one as Behring's Straits, especially 

 when we consider that several of the species enumerated 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 Yenesay and of China is very limited : — 



Redstart. 



Willow-Warbler. 



Kedge-Warbler. 



Rough-legged Buzzard. 

 Hooded Crow. 

 Jackdaw. 

 House Sparrow. 

 Northern Bullfinch. 

 Tree Pipit. 

 White Wagtail. 

 Fieldfare. 

 Redwing. 



Capercailzie. 



Golden Plover. 

 Dotterel. 

 Ringed Plover. 

 Little Stint. 



