264 POUCHED MAMMALS. 



chiefly arboreal, moving awkwardly when on the ground, and when pursued 

 always endeavouring to gain a tree with all possible speed. Its movements are 

 usually comparatively slow and sluggish, and, although mainly nocturnal, it may not 

 unfrequently be seen abroad in the daytime. Koalas are generally found in pairs : 

 and spend the day either high up on the tree-tops or in hollow logs. They are 

 purely herbivorous, and subsist chief!}- on the leaves of the blue gum-tree, although 

 at night they descend to the ground in order to dig for roots. In the evenings 

 these animals slowly creep along the boughs of the giant gums, the females often 

 having a solitary cub perched on their backs. When irritated or disturbed, the 

 koala utters a loud cry, variously described as a hoarse groan, and a shrill yell. 

 Giant Extinct The superficial deposits of Australia have yielded evidence of 



Phaianger. the former existence in that country of a phalanger {Thylacoleo 

 ca riiifex) far exceeding any of the living forms in point of size, and remarkable 

 for the exceedingly specialised character of its dentition. The functional teeth, as 



shown in the accompanying figure of the 

 skull, were, indeed, reduced to a pair of 

 large incisors, and a single elongated cut- 

 ting premolar on each side of both the 

 upper and lower jaws: the latter tooth 

 evidently corresponding to the permanent 

 premolar of the rat - kangaroos (see the 

 figure on p. 237). Such other teeth as 

 remain were small, and of no functional 

 importance. The skull is unique among 

 Marsupials in that the sockets of the eyes 

 PHiiA-N-GER (J nat. size). are completely surrounded by bone. 



This huge phalanger received its 

 technical names on the supposition that it was of purely carnivorous habits ; but 

 from the resemblance of its dentition to that of the existing members of the 

 family, it seems more probable that its diet was mainly of a vegetable nature. 



The Wojebats. 



Family Peascolomyid^:. 



The wombats of Australia and Tasmania, where they are represented by three 

 existing species all referable to the one genus Phascolomys, constitute the last 

 family of the herbivorous Marsupials. These animals are of considerable size, and 

 characterised externally by their massive build, short and flattened heads, broad flat 

 backs, and extremely short and thick legs : their hind-feet being plantigrade. 

 Their ears are small or of moderate size, and more or less pointed ; the eyes are 

 small, and the tail is reduced to a mere stump. The fore-feet have five toes, of 

 which the first and fifth are considerably shorter than the remaining three, all being 

 furnished with powerful and somewhat curved nails. In the hind-feet the inner 

 or "great" toe resembles that of the phalangers in being unprovided with a nail, 

 although it cannot be opposed to the rest ; the others have strong curved nails and 



SKULL OF THE GIAXT EXTINCT 



