CIlAl*. XVU.l 



MAMMALIA. 



253 



The Wombats are tail-less, terrestrial, burrowing animals, about 

 the size of a badger, but feeding on roots and grass. Ihey 

 inhabit South Australia and Tasmania (Plate XT. vol. i. p. 430). 



An extinct wombat, as large as a tapir, has been found in the 

 Australian Pliocene deposits. 



General Iicmarks on the Distribution of Marsnpialia. 



"\\'e have here the most remarkable case, of an extensive and 

 liighly varied order being confined to one very limited area on 

 the earth's surface, the only exception being the opossums in 

 America. It has been already shown that these are compara- 

 tively recent immigrants, which have survived in that country 

 long after they disappeared in Europe. As, how^ever, no other 

 form Itut that of the Didelphyidie occurs there during the 

 Tertiary period, we must suppose that it was at a far more 

 remote epoch that the ancestral forms of all the other Marsupials 

 entered Australia ; and the curious little mammals of the Oolite 

 and Trias, offer valuable indications as to the time vhcn this 

 really took place. 



A notice of these extinct marsupials of the secondary period 

 will be found at vol. i. p. 150. 



Order Xni.—MONOTREMATA. 



Family 83.~OENlTHORHYNCHII).E. (1 Genus, 1 Species.) 



General Distributiox. 



Xkotropical 



KlB-REOIONS. 



NE.VRtTIC I P.VL.-EARCTIC 

 SaB-RE3I0N3. SuB-IlEOIONy. 



Ethiopian 

 Sub-regions. 



Oriental 

 Slb-kecions. 



Australian 

 Sub-regions. 



- 2 



Tile OriiilJwrJri/nchiis, or duck-billed Platypus, one of the most 

 remarkable and isolated of existiug mammalia, is found in East 

 and Snuth Australia, and Tasmania. 



