442 BEARS CHAP. 
from living Mustelines by its comparatively long legs. In this 
genus as in several others there are two upper molars. 
Fam. 8. Ursidae.—This family is nearly universal in dis- 
tribution, and consists of but three genera, Ursus, Melursus, and 
Aeluropus. 
Ursus has the palms and soles naked except in the Polar 
3ear, which needs a furry sole to walk with ease upon ice 
surfaces. The ears are fairly large, and the nose may or may 
not be traversed by a median groove.’ The molar formula? is 
Pm+ M2. The brain is naturally (because of the size of the 
animals of this genus) richly convoluted. The lobate kidneys 
have already been mentioned in defining this family (see p. 426). 
A very large number of species of Bears have been described. 
Fic. 224.—Himalayan Bear. Ursus tibetonus. x +5 
sut it is the opinion of Mr. Lydekker* and of others that many 
of these are really to be referred to the European Brown Bear ; 
in this event the Grizzly of North America, the Isabelline Bear, 
the Syrian Bear, a Bear from Algeria, the Kamschatkan and 
Japanese Bears, besides the extinct Ursus fossilis of Pleistocene 
caves, are to be regarded as slight modifications of Ursus 
arctos.- On the other hand, the great Cave Bear, U7. spelaeus, 
1 Even apparently in the same species. 
2 The number of premolars is reduced in the Polar Bear. 
3 «*The Blue Bear of Thibet,” etc., Proc. Zool Soc. 1897, p. 412. 
