MAMMALS. 



371 



the lower jaw, serve at once to distinguish any marsupial 

 skeleton. The living marsupials have a peculiar distribu- 

 tion : they are restricted to warmer America and the chain 

 of islands extending from Australia to the Celebes. Fossil 

 forms are found in Europe as well. 



The North American species are all opossums forms 

 with prehensile tails which have given rise to the expres- 

 sion 'playing 'possum/ from their habit of feigning death 



FIG. 160. Pelvis of Opossum. (After 

 Minot.) M, marsupial bone; il, 

 ilium ; is, ischium ; p, pubis. 



FIG. 161. Opossum (Didelphys vir- 

 giniana). After Audubon and 

 Bachman. 



when disturbed. Their food is chiefly insects, but birds, 

 eggs, etc., are not despised. 



Australia is the real home of the marsupials; indeed, at 

 the time of its discovery this continental island contained 

 only marsupials, if we except mice and the dingo, or 

 native dog. In this region are found forms which recall 

 animals of different groups occurring in other parts of the 

 world. Thus the wombat resembles in size and teeth the 

 beaver; the thylacines in habits and in form are dog-like, 

 while the phalangers in size and appearance arc like the 

 flying squirrels, and, like those animals, they have that 

 same fold of skin which enables them to glide through the 



