II VI) ROM YS CHRYSOGASTER, Geoff. 
Golden-bellied Beaver-Rat. 
Hydromys chrysog aster, Geoff. Ann. Mus., tom. vi. p. 81. tab. 36. fig. A.— Gray, List of Mamm. in Coll. Brit. Mus., 
p. 121. 
The first specimens of Mammalia transmitted to Europe from Australia after the discovery of that country 
were from New South Wales and Van Diemen’s Land; and among others the present animal attracted, at 
a very early period, the attention of the French naturalists, one of whom — the celebrated Geoffroy St. 
Hilaire — assigned to it the name of Hydroynys chrysogaster, a name very suitable to the animal from the 
localities above mentioned ; similar Beaver-Rats are, however, universally spread over the whole of the 
southern portion of Australia, including the eastern and western confines of that continent ; but the animals 
from each of these localities appear to me to be distinct species ; and a most complete series of the whole 
of them being now before me, I think I shall be able to point out, in my account of each of them, characters 
of sufficient importance to be regarded as specific. 
The present species may he distinguished from all its congeners by the bright golden colouring of the 
sides of the face, lips, throat, shoulders, flanks and belly, the darker colouring being confined to the crown 
of the head and the upper part of the hack only, whereas in two of the other species this dark colouring 
occupies so much of the upper part of the body as to include the shoulders and part of the fore arm ; and, 
however near the whole of the species may assimilate in size, the present is the largest, as well as the one 
in which the colouring is the most contrasted and brilliant. 
The native habitat of the Hydromys chrysogaster is New South Wales and Van Diemen’s Land. It is 
strictly fluviatile in its habits, frequenting the muddy sides of creeks and water-holes, and the banks of the 
larger rivers and inlets of the sea. Rather shy in its disposition and nocturnal in its movements, it is not so 
often seen as might be supposed ; at the same time it is by no means difficult to be procured when such an 
object is desirable. As might be inferred from the structure of its hind feet, the water is its native element ; 
it swims and dives with the greatest facility, and easily secludes itself from view amidst the sedges lining 
the water’s edge, or by descending to its hole after the manner of the common Water Vole of Europe. 
Like many other of the Australian Mammals, it reposes much on its hinder legs, in which position it may 
frequently be seen on large stones, snags of wood, or any other prominence near the water’s edge. 
Head, ears, back, outer surface of the hinder limbs, the portion of the body posterior to them and the 
base of the tail mingled black and buff, the former hue predominating ; sides of the face, of the body, all 
the under surface and the inner side of all the limbs rich deep reddish orange ; outer surface of the arms 
deep brown ; upper surface of hinder feet pale glaucous buff, passing into brown on the tips of the toes ; 
basal half of the tail black, apical half white. 
The figures are somewhat smaller than life. 
