MARSUPIALIA. 



533 



Kangaroos " fonn the genus Petrogale, and inhabit the moun- 

 tainous regions of North-western Australia. 



The Kangaroo-rats {Hypsiprymnus) differ from the true Kan- 

 garoos chiefly in their smaller size, and in the presence of well- 

 developed upper canines (fig. 206, B), and in having scaly 

 tails. They are diminutive nocturnal animals, and they live 

 mostly upon roots. 



■ c. Carpop/iaga. ^-IntermediaXe between the Kangaroos and the 

 typical members of the present section (the Phalangers) is the 

 Phascolarctos — the " native sloth " or " bear " of the Australian 

 colonists and the " koala" of the natives (fig. 205). This curi- 

 ous animal is about two feet in length, having a stout body, 

 covered with a dense bluish-grey fur. The tail is wanting ; and 

 the feet are furQished with strong curved claws, which enable 

 the animal to pass the greater part of its existence in trees. In 



Fig. 206, — A, Dentition of a Carnivorous Marsupial {^kylacinusij showing the long 

 and pointed canines and the trenchant molars and pra^niolars. B^ Dentition of a 

 herbivorous Marsupial iJiypsiprymnHs)^ showing the flat-crowned molars. (After 

 Owen.) c Canine teeth ; it Incisors. 



this it is greatly assisted by the fact that all the feet are pre- 

 hensile, the hallux being opposable, and the digits of the fore- 

 limb divided into two sets, the thumb and index-finger being 



