482 ZOOLOGY. 
is from the tertiary deposits of Alabama, which must have reacbed a very 
large size. Another, smaller, is from South Carolina. 
The Trichechide, or walruses, which we have already described among 
Herbivora, were formerly since near the seals among Pinnipedia. 
The family of Hydrarchide was established for an extinct genus (Hydrar- 
chos), which at first was supposed to have been the most gigantic creature 
ever called into existence. Indeed it was one of the largest at the time 
when it lived, but its remains have been found to belong to the genus 
Basilosaurus, or Phocodon. 
Group 2. Ungwieulata. 
This group is composed of those mammals whose food consists chiefly 
of flesh, generally of a living prey, which they devour with more or less 
avidity. Some of them, however, the bears for example, have almost a 
frugivorous diet, eating flesh only by necessity. To these habits corre- 
spond a set of teeth fitted for the wants of the animals. The incisors and 
canines are adapted to seize a prey to the best advantage, and the molars 
to tear it into pieces. ‘The limbs are sometimes short, and sometimes 
moderately long, never out of proportion; always strong built, either for 
the purpose of running after prey or of leaping upon it. The Unguiculata 
may be divided into two tribes. 
Tribe 1. Plantigrada. 
The animals of this tribe, when walking, place the whole sole of the foot 
on the ground, a circumstance which enables them to stand vertically 
upon their hind feet. They partake of the slowness and nocturnal life 
of the Insectivora. They are all provided with five toes to each foot. 
Most of those that inhabit cold countries pass the winter in a state of 
torpor. @¢ 
Fam. 1. URsID«, contains but one genus, Ursus (or bears), characterized 
by a large head, a body and limbs large and powerful, the body itself 
covered with long and shaggy hairs. The tailis very short. There is no 
glandular pouch. The number of the molars is variable, the four last are 
large and tuberculous. Several species of bears are found in North 
America. In common with the old continent there is the polar white 
bear, U. maritimus (pl. 114, fig. 11), which inhabits the Arctic seas. 
The black bear, U. americanus (pl. 116, fig. 10), inhabits the east and 
north of the United States, whilst in the western regions we have the 
grisly bear (U. ferox). The brown bear of Europe (U. arctos) 1s repre- 
sented in pl. 116, jig. 9. Several other black bears are found in the Kast 
Indies. 
The species of this genus were very numerous during the tertiary epoch, 
and their remains are found in nearly all bone caverns, especially in 
Europe. They have also existed in Brazil and the Hast Indies. 
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