E DENT A TES. 749 







foot. The clavicles and fore-arm are well developed. The epipubic or 

 marsupial bones are large. 



The kangaroos feed on herbage, and are often hunted down on 

 account of the 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. 



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. 



Numerous fossil forms related to the kangaroos are found in Australia, 

 some considerably larger than the existing forms. The gigantic Dipro- 

 todon australiSy which was as large as a rhinoceros, is related both to 

 the kangaroos and the phalangers. Except the S. American forms 

 already mentioned, Diprotodont marsupials are unknown, either living 

 or fossil, outside the Australian area. Forms related to the Polypro- 

 todonts are, on the other hand, common as fossils in both Europe and 

 America. In S. America, further, fossil marsupials related to the 

 Dasyuridse occur ; and as these are not known elsewhere, their presence 

 affords a further confirmation of the view that Australia and Patagonia 

 were once connected. 



Sub-Class EUTHERIA 

 EDENTATES 



The Edentates include a number of very distinct types, 

 which require at least two orders (a) the New World sloths, 

 ant-eaters, and armadillos; (&) the Old World pangolins and 

 aard-varks. The modern forms are specialised survivors of 

 waning and probably primitive stocks, and they show many 

 interesting protective peculiarities of structure and habit 

 which secure their persistence. Thus some are arboreal, 

 others are burrowers, and many are covered with strong 

 armature. 



While the existing sloths, ant-eaters, and armadillos are not nearly 

 related to one another, the numerous fossil Edentates found in S. 

 America connect them to a common stock. It is otherwise, however, 

 with the pangolins and the aard-varks. Some authorities separate 

 them (as Nomarthra or Effodientia) from the American Edentates 

 (Xenarthra) ; but according to others there is little evidence that the 

 pangolins and aard-varks are related to each other. In view of the 

 uncertainty, it will be readily understood that few "general characters" 

 of Edentates can be given. Almost the only common characters of 

 Edentates concern the dentition. Functional teeth may be absent, 

 but the ant-eaters (Myrmecophagidae) are the only forms which still 

 appear strictly edentulous. When present, the teeth are uniform, 

 usually simple, without roots, and with persistent pulp. They are 

 never present in the very front of the mouth, and they have not 



