4 
HOKN EXPEDITION—MAMMALIA. 
Tlie marsupial fauna is characterised, as might have been expected, by (1) the 
absence of almost all forms characteristic of the coastal and well-watered parts of 
the continent—that is, the Euronotian district ; (2) by the presence of a few forms 
confined to the district; (3) by the predominance of other forms which are found 
in the inland parts of Queensland, New South "Wales, Victoria, South and West 
Australia—that is, forms inhabiting the broad band of country previously referred 
to as surrounding the Eremian region on almost all sides. So far as the marsupials 
are concerned, this is a well-marked region. (4) By the presence of a few forms 
such as Trichosurus vulpecula, Sniinthopsis crassicaudaia, and N. murma^ which 
appear to be universally, or nearly so, distributed over the continent. 
A glance at the distribution of the species now recorded will show that there 
is only one of them which is as yet known only from the eastei’n side of the 
Eremian region and not also from the south and west. This is the rare 
Antechiiiomys iauiger, which has been found in the inland parts of Queensland and 
New South Wales. There can, however, be little doubt but that the range of this 
extends into West Australia. It will be seen on the other hand that there is a 
strong predominance of South and West Australian species, together with a smaller 
number of forms, inhabiting these districts as well as the inland parts of Queens¬ 
land and New South Wales and, to a lesser extent, the northern parts of 
Victoria. 
So far as is at present known thirteen genera are represented, six of which 
belong to the Diprotodontia and seven to the Polyprotodontia. The thirteen 
genera are represented by eighteen species, of which seven belong to the Diproto¬ 
dontia and eleven to the Polyprotodontia. To compare these numbers with the 
total number for Australia, including Tasmania, we find that of the Diprotodontia 
some twenty-four per cent, of the genera and seven of the species are represented, 
and of the Polyprotodontia some sixty-three per cent, of the total number of genera 
and twenty-live per cent, of the species. This proportionate representation in both 
cases is more closely similar to that of Tasmania than to that of any other division 
of the Australian region, and yet no two parts form a greater contrast to one 
another at the present day than do Central Australia and Tasmania. Whilst the 
latter owes its comparative poverty of diprotodont marsupials to the fact of its 
separation from the mainland before the period of their full development, the case 
is quite different with regard to Central Australia. In the latter the finding of 
abundant remains of extinct diprotodonts, some of huge size, has shown that at a 
former period it was the home of a fauna dependent upon a plentiful and constant 
vegetation such as does not now exist. 
