302 SIBERIA IN EUROPE. chap, xxiii. 



and Persia would be to the Volga by way of the Caspian 

 Sea. The line of migration would probably follow the Volga 

 to Kasan, and thence along the Kama to Perm and Cherdin, 

 close to the source of the Petchora. The course would then 

 continue down the Petchora as far as its junction with the 

 Ussa. It would then be reasonable to conclude that the 

 hardy species, which migrate early, would have plenty of 

 time to go round by Ust-Zylma; whilst the later arrivals 

 would leave the Petchora at Ust-Ussa, and cross direct to the 

 tundra. For example, the snow-bunting, hen-harrier, merlin, 

 bean-goose, shore-lark, snowy owl, wild swan, Bewick's swan, 

 and herring-gull are probably amongst the earliest breeders 

 on the tundra, and pass through Ust-Zylma, whilst the later 

 breeders on the tundra are not there at all. The following 

 birds are all summer migrants to the tundra, but were not 

 seen passing through Ust-Zylma during migration : — 



Yellow-headed Wagtail. 

 Arctic Tern. 

 Siberian Pipit. 

 Red-necked Pbalarope. 

 Long-tailed Duck. 

 Button's Skua. 

 Grey Plover. 



Dunlin. 



Richardson's Skua. 

 Dotterel. 

 Sanderling. 

 Curlew Sandpiper. 

 Little Stint. 



Most of these are very late-breeding birds, but why they 

 should breed late, or for what cause they seem to choose a 

 different line of migration, seems at present inexplicable. 

 Before a concdusion can be arrived at, many more facts must 

 be collected. The field of ornithological research is one in 

 which any amount of work may be advantageously done, 



