294 



ORDERS OF MAMMALIA. 



has been constituted for tlieir reception, on account of some 

 subordinate peculiarities in their dentition. Several very 

 similar forms have been described from the Miocene ; but 

 no undoubted Marsupials have been as yet detected in the 

 Pliocene deposits. 



In the Post-Tertiary period, on the other hand, the order 

 of the Marsupialia is represented by some very remarkable 

 forms. The most important of the remains in question have 

 been found in the bone-caves of Australia — the country in 

 which Marsupials now abound above every otlier part of the 

 globe ; and they show that Australia, at no distant geological 

 period, possessed a Marsupial fauna, much resembling that 

 which it has at present, but of forms comparatively of 

 gigantic size. In the remains from the Australian bone- 

 caves, almost all the most characteristic living Marsupials of 

 Australia and Van Diemen's Land are represented ; but the 

 extinct forms are usually of much larger dimensions. The 

 group of JMarsupials (Fossoria) represented by the living 

 Wombat {Pliascolomys) is represented in this way by con- 

 generic Tertiary forms, which must have equalled the Tapir 

 in size. This genus (fig. 606) belongs to the Diprotodont 

 division of the Marsupials, but the incisors have the peculi- 

 arity — otherwise unknown in the order — that they grow 



Fig. t)06.— Skull of Wuinbat. (.\fter Giebel.) 



from persistent pulps, in this respect resembling the iucisors 

 of the Eodents. Canines are wholly wanting and the dental 

 formula is — 



