THE PAL^EARCTIC REGION 189 



Section V. — The Eremian Sub-region 



The Eremian or Desert Sub-region of the Palsearctic 

 Region contains representatives of a larger number of 

 genera than the Europasian, and a higher percentage of 

 endemic forms, although even here we do not find so much 

 individual character as in some of the Sub-regions pre- 

 viously treated of. A considerable number of the genera 

 are common to this and the Ethiopian Region, which is, 

 perhaps, not to be wondered at, considering the long land 

 boundary which runs between them. 



Among the Ungulates only one genus is confined to this 

 Region — the Camel {Camelus), which is now found wild 

 only in certain desert tracts of Central Asia, being else- 

 where known only in a domesticated condition. But remains 

 of animals of this genus have been found in comparatively 

 recent beds both in India and Algeria. Except for this, 

 other indications seem to point to the fact that the Camels 

 must have had their origin in the New World, where they 

 are now represented only by the Lamas. But remains of 

 several allied genera of Camelid& have been met with in 

 the Tertiary beds of North America, where, however, they 

 have been long extinct. Bubalis, which contains the 

 Antelopes usually known as " Hartebeests," and Hyrax 

 (the Tree-conies) are common to this Sub-region and the 

 Ethiopian Region. Among the Rodents no less than five 

 genera are confined to the Sub-region, the most remarkable 

 of these being, perhaps, the Jerboas, or Kangaroo-rats, as 

 they are called, from having their hind legs elongated for 

 jumping purposes. The four known genera of Jerboas, 

 which contain a large number of species, are not found 



