INTRODUCTION 9 



in both regions. But the Marsupials of Australia seem 

 to have but a very remote connection with those of South 

 America, and there is at present no pakeontological evi- 

 dence of the former occurrence of the Australian forms, 

 or of forms allied to them, outside of Australia itself. 1 On 

 the other hand, the presence of fossil opossums (Didel- 

 pkyidas) in the Eocene beds of France, shows that the 

 South American forms were formerly more widely spread. 



Professor Huxley has also cited the Parrots (Psittaco- 

 morphse) "as helping, together with the three-toed Ratitte, 

 to bind together the widely-separated portions of the south 

 world." But on referring to the account of the distribu- 

 tion of the Parrots in Salvadori's recently published cata- 

 logue (8), it will be found that out of the six families into 

 which he divides the group, five are practically confined 

 to the Australian Region, and that the remaining one is 

 widely spread throughout the tropical regions of both 

 hemispheres. The most recent arrangement of this 

 family, therefore, gives little support to Professor Huxley's 

 arguments. 



Looking, again, to the distribution of the Ratita 

 (wingless birds), we find the Neotropical form (the Rhea) 

 more closely connected with the Ostrich, the Ethiopian 

 form, and that they both differ considerably from the 

 Emus, Cassowaries, and Kiwis, the three Australian repre- 

 sentatives of this order. Thus, then, there seems to be 



1 Recently Seftor Ameghino has described from the Santa Cruz beds 

 of Patagonia, which are probably of Eocene age, certain fossil mammals 

 which he has referred to the Dusyuridat, one of the Australian families. 

 Again, Mr. Thomas' Ccenolestes (see P. Z. S. 1895), is also believed to be 

 allied to the Australian Diprotodonts. If these relationships should turn 

 out to be correct, it will indicate further evidence of some connection 

 between South America and Australia, though at a considerably remote 

 epoch of geological time. 



