FAMILIES OF MARSUPIALS. ^i 



fore-legs, and the animals move by leaps. The fore-feet have 

 five clawed digits ; ni the hind-feet, the nallux is absent except 

 in one case, tne second and third toes are rather slender, tne 

 tourth is very large and has a strong claw, the filth is somewhat 

 smaller, all the lour toes are bouna together by the skin. The 

 tail is long. The stomach is sacculated. 

 Examples : — The true Kangaroos, e.g. , Macroptis; the rat-kangaroos 

 or potoroos (totorous) ; the genus hyfsiprymnodon, with a 

 foot approaching that ot the Pnalangers. 

 The true Kangaroos, Delonging to the genus Macropus, include the 

 largest living Marsupials, but witnin the genus there is much difference 

 in size. 



The grey Kangaroo (Af. giganteus), lives on the grassy plains of 

 Eastern Australia and Tasmania, and is as tall as a man ; the Wallabies, 

 at home in the bush, are smaller, and some are no bigger than rabbits. 



The hind-limbs seem disproportionately long, and are well suited 

 for rapid bounding. The long tail carried horizontally, helps to balance 

 the stooping body as the animal leaps, and it gives additional stability 

 to the erect pose. The fore-limbs sometimes come to the ground when 

 the animal is feeding, and in the largest species, they are strong enough 

 to throttle a man. 



The fore-limbs bear five clajved digits, the hind-feet have only four. 

 The hallux is absent ; the fourth toe is very long ; the fifth is about half as 

 large ; the third and second are too slender to be useful for more than 

 scratching, and are bound together by the skin, being what is technically 

 called syndactylous. The length ot the hind-limb is due to the tibia- 

 and fibula, and to the foot. The clavicles and fore-arm are well de- 

 veloped. The epipubic or marsupial bones are large. 



Ine Kangaroos feed on herbage, and are otten hunted down on 

 account of tne damage which they do to pastures and crops. The 



sharp incisors ^ are suited for cropping the grass and herbs, which the 



ridged and tuberculated molars - crush. In many ways the dentition 



is difiicult to understand, thus premolars and molars move forward as 

 the animal grows older. 



As the Kangaroos are exclusively herbivorous, it is not surprising to 

 find that the stomach is large and complex, with numerous saccules on 

 its walls. The whole gut is long, and there is a well-developed caecum. 



Among extinct Marsupials there were some gigantic forms, notably 

 Diprotodon australis as large as a Rhinoceros. It is likely that many 

 of the early Mesozoic mammals were Marsupials. 



A remarkable new type of Marsupial (Notoryctes typhlops) has been 

 recently discovered by Dr E. C. Stirling. Four or five cervical vertebrx 

 are fused, there is a keeled sternum, and a bird-like pelvis. The eyes 

 are rudimentary and beneath the skin. The marsupial bones are small 

 nodules. The animal is mole-like and a rapid burrower. 



