132 VERTEBRATA: MAMMALIA. 



they also, as we have seen on page 67, constitute a distinct 

 sub-class of the Mammalia. They are separated from the 

 true Mammalia by their peculiar structure, which is con- 

 nected with the production and nourishing of their young. 



Their young are brought forth in an exceedingly im- 

 mature state of development ; and in most cases, are 

 received into a pouch or sack which is situated on the 

 abdomen of the mother, where they are nourished by 

 in ilk till they have acquired a degree of development cor- 

 responding to that in which other mammals are born. 

 Even after they are able to walk the young resort to the 

 pouch of the mother for safety in time of danger. The 

 name of this group comes from the Latin marsupium, a 

 pouch. 



With the exception of one family, the Opossums, found 

 in America, the Marsupials are confined to Australia and 

 the adjacent islands. And it maybe added here that it is 

 a remarkable fact that nearly all the mammalia of Austra- 

 lia belong to this curious group of animals. 



The Wombats or Phascolomyidae are marsupials with a 

 heavy body, as large as that of a medium-sized dog or 



Fir,. 150. 



FIG. 151. 



Wombat, Phascolomys ursinus, Cuvier. Skull of Wombat. 



larger, but with very short legs. In their teeth they are 

 closely allied to the Rodents, as they have only two in- 

 cisors in each jaw, and each of their molars has transverse 

 ridges. 



The Kangaroos or Macropoclidce are marsupials which 

 have a remarkable development of their hinder parts. 



