MAMMALIA—OPOSSUM. 215 
say, that they live on the broad leaves of a certain vegetable which grows 
in the sea, and that they eat neither flesh nor fish. But I imagine all these 
opinions have but a weak foundation ; and there is reason to think, that the 
walrus, like the seal, lives on prey, especially herrings and other fish; for 
it does not eat at all when upon land, and it is chiefly hunger which obliges 
it to return to the sea. 
The fat of the walrus furnishes from one to two barrels of oil; and the 
skin is capable of being manufactured into a strong and elastic leather. 

ORDER FIVE—MARSUPIALIA. 
Animats of this order have teeth different in the different genera. The 
young are brought forth prematurely, often into a pouch formed by a fold of 
the skin of the abdomen of the females, inclosing the mamme; marsupial 
bones in both sexes ; thumb of the hind feet sometimes wanting, sometimes 
very distinct, without nail, opposable to the other toes. 
THE) VPRGLNA AN OPOSSUM 
YI 

THE vpossum is found in Brazil, Guiana, Mexico, Florida, Virginia, and 
other temperate regions of this continent. The female has under the belly 
a large cavity, where she receives and suckles her young; she produces 
often, and a great number of young each time, most authors say, four or 
five, others six or seven. 

1 Didelphis Virginiana, Penn. The genus Didelphis has ten upper and eight lower inci- 
sors ; two upper and two lower canines ; twelve or fourteen upper and fourteen lower molars. 
Two superior intermediate incisors larger than the others; lower incisors equal; canines 
strong, compressed molars, the three first in the upper jaw triangular; the others crown- 
ed with points ; head long and conical; muzzle pointed, mouth much cleft; ears large, 
rounded and almost naked; five toes on all the feet; nails long aud bent; hind feet planti- 
yrade with the thumbs opposable, but destitute of nails; tail long, scaly, mostly de- 
prived of hair. 
