﻿EXTINCT FORMS. 349 



PART III. 



EXTINCT MARSUPIALS AND MONOTREMES. 



INTRODUCTORY. 



In addition to remains belonging to existing spec'.es, the 

 superficial deposits and caverns of Australia have yielded evi- 

 dence of the existence of a number of Marsupials belonging to 

 species, genera, or even families entirely distinct from all their 

 living allies, and in many cases attaining dimensions far ex- 

 ceeding any of those of the latter. All these extinct Marsu- 

 pials belong, however, to the same general groups as those now 

 inhabiting Australia ; and they for the most part appear to have 

 existed during the Pleistocene, or latest geological period, that 

 is to say, to the time when the Mammoth and Woolly Rhi- 

 noceros flourished in Europe. 



In South America we have likewise evidence that durinsr the 

 same period species of Opossum were abundant, at least a large 

 number of which were identical with those still inhabiting the 

 same country. When, however, we examine the older Tertiary 

 strata of Patagonia we find remains of extinct Marsupials which 

 appear, so far as the present evidence may be credited, to be 



