THE FAUNA OF BRITAIN. 95 



restricted and discontinuous ranges," he says, " along 

 the extreme western margin of Europe mark them 

 as decidedly older than those northern animals and 

 plants which have a circumpolar distribution." We 

 have indeed quite similar examples in the Oriental 

 migration, of which part is very ancient, surviving 

 here and there and exhibiting discontinuous distri- 

 bution. We may therefore look upon these American 

 immigrants as among the oldest members of that 

 northern stock which have survived in our islands 

 probably a mere remnant of a once luxuriant flora 

 and fauna. 



In order to show the importance of the Eastern or 

 Siberian element in the English, or, we might say 

 with Dr. Sclater, the Anglo-Scotian mammalian 

 fauna, I herewith give a list of the species of 

 mammals which probably migrated to Great Britain 

 from Siberia. I have marked with an asterisk those 

 which still exist in this country (not in Ireland), or 

 have become extinct within historic times. 



Canis lagopus. * Mus minutus. 



Gulo luscus. * Arvicola agrestis. 



* Mustela erminea. * amphibius. 



* putorius. arvalis. 



* vulgaris. * glareolus. 



* Sorex vulgaris. ,, gregalis. 

 Lagomys pusillus. ,, ratticeps. 



* Castor fiber. Equus caballus. 

 Spermophilus Eversmanni. Saiga tartarica. 



erythrogenoides. Ovibos moschatus. 



