s are not numerous,
they are widely spread over the earth, although absent from Africa
south of the Sahara and Australasia. As a rule, they are omnivorous,
or vegetable feeders, even the polar bear, which subsists for most of
the year on flesh and fish, eating grass in summer. On the other hand,
many of the brown bears live largely on salmon in summer. Among the
various species the white polar bear of the Arctic regions, _Ursus
(Thalassarctus) maritimus_, differs from the rest by its small and low
head, small, narrow and simple molars, and the presence of a certain
amount of hair on the soles of the feet. The typical group of the
genus is represented by the brown bear (_U. arctus_) of Europe and
Asia, of which there are many local races, such as the Syrian _U. a.
syriacus_, the Himalayan _U. a. isabellinus_, the North Asiatic _U. a.
collaris_, and the nearly allied Kamchadale race, which is of great
size. In Alaska the group is represented by huge bears, which can
scarcely claim specific distinctness from _U. arctus_; and if these
are ranked only as races, it is practically impossible to regard the
Rocky Mountain grizzly bear (_U. horribilis_) as of higher rank,
although it naturally differs more from the Asiatic animal. On the
other hand, the small and light-coloured _U. pruinosus_ of Tibet may
be allowed specific rank. More distinct is the North American black
bear _U. americanus_, and its white relative _U. kermodei_ of British
Columbia; and perhaps we should affiliate to this group the Himalayan
and Japanese black bears (_U. torquatus_ and _U. japonicus_). Very
distinct is the small Malay sun-bear _U. (Helarctus) malayanus_,
characterized by its short, smooth fur, extensile tongue, short and
wide head, and broad molars. Finally, the spectacled bear of the
Andes, _U. (Tremarctus) ornatus_, which is also a broad-skulled black
species, differs from all the rest in having a perforation, or
foramen, on the inner side of the lower end of the humerus. A second
genus, _Melursus_, represented by the Indian sloth-bear (_M.
ursinus_), differs from the preceding in having only two pairs of
upper incisors, the small size of the cheek-teeth, and the extensile
lips. Ants, white-ants, fruits and honey form the chief food of this
shaggy black species,---a diet which accounts for its feeble dentition
(see BEAR).

[Illustration: FIG. 6.--The Parti-coloured Bear, o