324 



VEUTEHTtATE ANIMALS. 



American Opossums {Diddphidcn), may be lueiitioiicd. The Bandi- 

 c-.iuts are little, labbit-like Australian animals, which live upon 

 insects, and seem to till the place held in the Old World by the 

 Hedgehogs and tlie Shrew-mice. The species of Dasi/Krws, thougli 

 of small size, are very ferocious ; and the Thylacine grows to the 

 size of a shepherd's dog, and is quite capable of destroying animals 

 as big as sheep. About twenty species of Didelphidce are known, 

 and the}' are all exclusively confined to the American continent. 

 They are all of small size, h.ave prehensile tails, and mostly live 

 among trees. The best -known species is the Virginian Opiossum 

 {Didclpliys Yirijiiiiitna). Another spiecies of Opossum, the Didelphys 

 diinfiijera (fig. 2:i9), carries its young about on its back, the young 

 clinging to the mother by twining their prehensile tails round hers. 



(.)RDER III. Edentata or Bruta. 



This order of Placental Mammals comprises the Ant-eaters, Arma- 

 dillos, and Sloths, and is characterised by the fact that the teeth are 

 not covered with enamel, have no complete i-oots, and are never re- 



Fig. 230.— A, Kiile-\-icw of (lie skull of Brrulypva cumillim'r ; B, Siile-view of the skull 

 of Dasiipiu tj'ga;^. (After Gieliel.) 



placed by a second set. As a rule, the teeth (fig. 230) are simple 

 cylinders, jjlaced at a little distance from each other. Further, in 

 none (jf the Edentates ar(! there any central incisor teeth, and in all 



