VERTEBRATA: MAMMALIA. 66 1 



Though they form an extremely natural order, sharply sepa- 

 rated from all the rest of the Mammals, the Marsupials form 

 a large and varied group. In fact, this order, from being the 

 almost exclusive possessor of a continent as large as Austra- 

 lia, has to discharge in the economy of nature functions which 

 are elsewhere discharged by several orders. 



The Marsupialia are divided by Owen into the two primary 

 sections of the Diprotodontia and Polyprotodontia, comprising 

 the following subordinate divisions : 



(A.) DIPROTODONTIA. Lower incisors two in number; 

 canines rudimentary or wanting ; molars mostly with broad 

 crushing crowns. 



a. Rhizophaga . In this section is the well-known Australian 

 animal the Wombat (Phascolomys fossor], often called by the 

 colonists the "badger." The Wombat is a stout, heavy 

 animal, which attains a length of from two to three feet. The 

 legs are very short and stout, and the animal burrows with 

 ease by means of strong, curved digging-claws, with which the 

 fore-feet are furnished. The tail in the Wombat is quite rudi- 

 mentary, and the whole body is clothed with a brown woolly 

 hair. In its dentition (fig. 361) the Wombat presents a curious 



Fig. 361. Skull of Wombat. (After Giebel.) 



resemblance to the herbivorous Rodents. There are two 

 incisors in each jaw, and these are long and rootless, growing 

 from permanent pulps. There are no canines, so that the 

 incisors and prsemoiars are separated by a considerable space. 

 The dental formula is 



oo T T A. 4 

 C ; pm ; ;;/ ~ 24. 



i i oo i i 44 



