INTEODUCTION. 
If the scientific interest roused by the numerous discoveries made in Australia 
during the first half of this century he not as intense at present, this is due 
mainly to the fact that the natural products of tins wonderful country are on 
the whole pretty well known, and that the public, as well as scientists, have 
had opportunities to familiarise themselves with the strange form of most of 
the animals that inhabit it. 
Not a Museum of Natural History, not a Zoological Garden, would he 
worthy of the name if they did not contain at least some sjiecimens of that 
great series of Marsupials, large and small, and of the birds, noteworthy 
either by their shape or variety of plumage, that the Australian Hegion 
supports, as well as that unique animal whose body is covered by an otter’s 
skin, and whose muzzle is replaced by a hill like a duck’s, a fact to which is 
due the name of OrnitJiorhyncliiis l)y which it is generally known. 
The living fauna of this country presents this singular character — that it 
can he compared to no other. Its principal types have no representatives in 
countries of similar latitudes providing analogous conditions of life. 
In Europe it is necessary to go hack to the beds of the Great Oolite 
before we meet with remains of a mammal whose structure is similar to that 
of the Marsupials of Australia. 
This isolation of living races has given rise to theories formed more 
or less on the formation of the immense continent that these races inhabit. 
Some are of opinion that its fauna represents the direct descent of that which 
vanished in Europe with the deposition of the last Jurassic beds, and that the 
Australian land has remained above water duriug the different periods in 
which more recent beds were laid down in the rest of the world. 
But the discovery, in Australia itself, of well developed beds belonging 
to the Cretaceous and Tertiary Systems has demolished this theory ; it has 
proved that the land of this country has not been subject to geological 
phenomena differing from those that have been observed in all other parts. 
The only question that remained to be solved was whether there was, 
between its fossil fauna and flora and those of other countries, the same 
difference of form and organisation which characterises so markedly the 
living fauna and flora. 
