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 chiefly 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 ery, variously described as a hoarse groan, and a shrill yell. 
Giant Extinct The superficial deposits of Australia have yielded evidence of 
Phalanger. the former existence in that country of a phalanger (Zhylacoleo 
carnifex) 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 
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. 

SKULL OF THE GIANT EXTINCT 
PHALANGER (34 nat. size). 
THE WOMBATS. 
Family PHASCOLOMYID. 
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 
