VERTEBRATA: MAMMALIA. 



663 



utive as compared with the posterior, and the fore-limbs are 

 quite small, but have five well developed toes armed with 

 strong nails. The head is small, with large ears, and the 

 dental formula is 



i i o o 



i i 



4 4 



= 28 . 



There are therefore six upper incisors, two lower incisors (the 

 latter horizontal, fig. 362), and no functional canines (though 

 rudimentary upper canines are present in the young of some 

 of the Kangaroos, at any rate). The stomach is complex, and 

 sacculated. The Kangaroos are all herbivorous, and mostly 

 live, either scattered or gregariously, on the great grassy plains 

 of Australia. The " Tree-kangaroos," however, (constituting 

 the genus Dendrolagus) live mostly in trees ; and in adapta- 

 tion to this mode of life, the fore-legs are nearly as long and 



Fig. 364. A, Dentition of a herbivorous Marsupial (Hypsiprymwis cuniculus\ showing 

 the upper canine (c) and the great grooved first praemolar (a a); B, Lower jaw of an 

 entomophagous Marsupial (Perameles obesuld) ; C, Lower jaw of a predatory Mar- 

 supial (Dasy^lrus ursinus). (After Giebel and Waterhouse.) 



strong as the hind-legs, the tail is not used as a support, and 

 the claws are long, curved and pointed, while small upper 

 canines are present. They are natives of New Guinea. The 

 " Rock-kangaroos " form the genus Petrogale, and inhabit the 

 mountainous regions of North-western Australia. 



