XU FOSSIL BEARS 445 
Pleistocene times, was one of the commonest of Carnivorous 
creatures during the very early times of the present era. It 
was as huge as a Polar Bear or a Grizzly. The skull is remark- 
able for the fact that the first three premolars, which are small 
in all Bears, dropped out early in life. An immense number of 
names have been given to what are in all probability the same 
species as this Cave Bear of remote antiquity. 
Hyaenarctos is the oldest genus of true Ursidae. It goes 
back into Middle Miocene times, and ranged over Europe and 
North Africa. 
Arctotherium is an American genus of Pleistocene times. 
The likeness of some of the extinct Canidae to Bears has been 
already commented upon. 
