DISTRIBUTION OF THE AUSTRALIAN MA11SUPIATA. 637 
Tlie preceding table shows that the great metropolis of the 
Opossums is Brazil, and that in proportion as the various 
districts mentioned are more widely separated from that pro¬ 
vince, so do the species decrease in number. The natural 
barrier of the Cordilleras, it seems, has prevented the passage 
of a single species from the eastern, to the ■western side of 
those mountains. The Great River Plata forms the southern 
boundary of the province of the Opossums 1 . 
With respect to the distribution of the Marsupiata inhabit¬ 
ing Australia and the neighbouring islands, some remarks 
will be found in the introductory observations upon the 
group; and at page 3 is a table showing the distribution of 
the species of Cuscus which inhabit the islands north of 
Australia; in that table the name chrysorrlios should be 
inserted in the column for New Guinea, a specimen of that 
species of Cuscus having been shot by Mr. Jukes in that 
island 2 . The species of Marsupiata now known to be 
natives of New Guinea are as follows :— Cuscus maculatus , 
Cuscus chrysorrlios , Dendrolagus ursinus, Dendrolagus 
inustus, Macropus Brunii , Petaurus (sciureus ?), Phasco- 
gale me las } and Perameles D orey anus. 
Australia may be conveniently divided into five principal 
divisions or districts, of which the East, West, North, and 
South portions of the main land will each form one province, 
and Van Diemen’s Land the fifth. Of these provinces, the 
northern one has the greatest number of species peculiar to 
it, since out of ten species discovered in that part of Australia, 
1 With regard to the numerous so-called species forming the first section of 
the genus Didelphys, I have to observe, that they have been founded for the 
most part upon very trivial characters, and I think it highly probable that 
when sufficient materials are collected for a rigorous examination of the group, 
it will be found to be composed of but one or two variable species, instead of 
seven or eight, as now supposed. 
2 The specimen has recently been presented by Mr. Jukes to the British 
Museum. 
