MAMMALIA 



323 



inches, not including the tail. M. gigantius is reported by Sir Josoiih l^anks 

 as good for food. It is said that a large kangaroo in rapid flight Icai)s 20 to 

 30 feet at a bound. The female will weigh 120 pounds, some old males weigh 

 200 pounds. The smaller species of kangaroos furnish the most fur and 

 leather and the best venison. About 350,000 are sold in London annually. 

 Rock wallabies (genus Pelrog'ale) have a shorter claw on the hind foot 

 and a more .slender tail, which is thickly covered with hair and never used in 

 locomotion (Fig. 264). The tail is used as a balancer, as they leap from 



>^^ 



Fig 264.—Petrogale xanthopus. The rock wallaby, with young in pouch, 

 (After Vogt and Specht.) 



rock to rock. They are found in Australia only. The nocturnal genus 

 (Bettongia) and others have sometimes been inaccurately called " rat 

 kangaroos." The four species are subterranean, with prehensile tails, 

 with which they carry their food, grass, roots, and leaves. One species 

 burrows to a depth of 10 feet. It is found in Tasmania and Australia. 



Order III. Edenta'ta. — The five families of this order are 

 arboreal, terrestrial, or subterranean, with clawed limbs. They 



