THE PAL^EAECTIC KEGIOK 315 



forms of animal life, and it is therefore well to con- 

 sider it first in order. 



In enumerating the most important animal groups 

 characteristic of this and other regions, it must be 

 clearly understood that such groups are not always 

 absolutely confined to one region. Here and there 

 they will often overlap the boundaries, while in other 

 cases single species may have a wide distribution in one 

 or more of the adjacent regions ; but this does not at all 

 affect the main fact, that the group as a whole is very 

 abundant and very widely spread over the region in 

 question, while it is very rare, or confined to a very 

 limited area in adjacent regions, and is therefore spe- 

 cially characteristic of the one as compared with other 

 parts of the world. Bearing this in mind, we shall find 

 that the Palsearctic region is well characterized by a 

 considerable number of typical groups, although, as we 

 shall presently see, it has in recent geological times 

 lost much of its ancient richness and variety of animal 

 life. 



Among Mammalia the groups most characteristic of 

 this region are the moles (Talpidse), a family consisting 

 of eight distinct genera which range over the whole 

 region, but beyond it barely enter the Oriental region 

 in North India, and the Nearctic region in North- West 

 America ; camels, confined to the deserts of North 

 Africa and Asia ; sheep and goats (Capra), only found 

 beyond the region in the Nilgherries and Rocky Moun- 

 tains ; several groups of antelopes, and many peculiar 

 forms of deer ; hamsters (Cricetus), sand rats (Psam- 

 momys), mole rats (Spalax), and pikas (Lagomys), with 

 several other forms of rodents. Wolves, foxes, and 



