XII 



PHYLUM CMORDATA 



523 



nearly equally developed. In the hind-foot the fourth toe 

 is much longer and stouter than the others, while the second 

 and third are small and slender, and united together by a 

 web of skin, and the first 

 is vestigial or absent. 

 The marsupium has its 

 opening directed back- 

 wards. 



The Wombats (Phas- 

 colomyidce) are large, 

 heavy, thick-bodied, bur- 

 rowing animals, with 

 short flattened heads, 

 short thick limbs pro- 

 vided with strong claws 

 on all the digits except 

 the hallux, and with the 

 second, third and fourth 

 toes of the hind-foot 

 partlyconnected together 

 by skin. The tail is very 

 short. The Kangaroos 

 and their allies (Macro- 

 podida) (Fig. 293) are 

 adapted, as regards their 

 limbs, for swift terres 

 trial locomotion. They 

 have a relatively small 

 head and neck, the fore- 

 limbs small, and each provided with five digits : the hind-legs 

 are long and powerful, and 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 



