’ 
EXTINCT OPOSSUMS. 271 
Brazil and South Africa, and nowhere else. Then, again, the 
remarkable Anomodont reptiles (Dicynodon, &c.) of South 
Africa are closely connected with those of India; while the 
respective alliances between the extinct Labyrinthodont Am- 
phibians and the Secondary floras of South Africa, India, and 
Australia are too well known to need more than mention. 
It appears, then, that, altogether apart from the extinct 
Marsupials, the common factors connecting the faunas and 
floras of the four great southern prolongations of the con- 
tinental land of the globe undoubtedly point, not only toa more 
or less intimate connection between those several areas, but 
also to their more or less partial isolation from the more 
northern lands. 
FAMILY DIDELPHYID& (swfrd, p. 193). 
GENUS DIDELPHYS (sura, p. 196). 
The number of species of Opossums which have been 
recorded in a fossil state is so large that it would be weari- 
some to detail them here, more especially as the teeth and 
jaws of all the members of the family are very similar in 
structure, and consequently difficult to distinguish from one 
another in a fossil state. It will consequently suffice to 
notice some of the chief formations in which remains of the 
genus occur. 
In the first place, remains of a large number of species of 
Opossums are found in the Pleistocene deposits of the caverns 
of Minas Geraes, Lagoa Santa, inland from Rio de Janeiro, 
Brazil. ‘The greater number of these remains appear inse- 
parable from species still inhabiting the same country ; and 
they have been referred to species ranging in size from D. AZar- 
supialis to the minute D. pusilla. 
In the Tertiaries of Argentina teeth and jaws of Opossums 
have been discovered which are assigned to extinct species 
