403 



ZOOLOGY 



SECT. 



with the second, third and fourth of the hind-foot partly connected 

 too-ether by skin. The tail is very short. The Kangaroos and their 

 allies (Macropodidse) (Fig. 1046) are adapted, as regards their limbs, 

 for swift terrestrial locomotion. They have a relatively small 

 head and neck, the fore-limbs small, and each provided with five 

 clioits: the hind legs long and powerful; rapid progression is 

 effected by great springing leaps, with the body inclined forwards 

 and the fore-limbs clear of the ground. The foot is narrow and 

 provided with four toes, the hallux being absent ; the two inner 

 (second and third) small and united together by integument, 

 while the middle one is very long and powerful. The tail is very 

 long, and usually thick. There is a large marsupium. The Tree- 

 Kangaroos differ from the ordinary Kangaroos in their shorter 

 and thicker hind-limbs, in which the second and third toes are 

 nearly as large as the fourth. 



The Phalangers (Phalangeridcc) are climbing Marsupials which 

 have both fore- and hind-feet prehensile ; the second and third 

 toes of the hind-foot slender and united by a web, as in the 



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FIG. 1047. Koala (Phascolarctos cinereus). (After Vogt and Speclit.) 



Kangaroo, but the hallux, which is nailless, opposable to them ; 

 the fourth and fifth nearly equal ; the tail is well developed and 

 prehensile. A number of Phalangers (Flying Phalangers) are 

 provided with lateral folds of skin extending from the fore- to the 

 hind-limbs and, acting as a parachute, enabling the animal, as in 

 the Flying Squirrels, to perform flying leaps from tree to tree. 

 The Koalas (Fig. 1047) differ from the Phalangers mainly in the 

 relatively thicker body and the vestigial tail. 



The Sloths (Bradypodidce) (Fig. 1048) are more completely 



