4 
MARSUPIATA. 
rock-kangaroos, and wliicli constitute the little section Petro - 
gale , one inhabits the hills of New South Wales, a second is 
found on the opposite side of the continent, a third has only 
been met with on the south coast, and the fourth on the 
north-west coast. 
Many similar cases might he noticed. No doubt, in a large 
district, such as New South Wales, are found several species 
of the same section, as, for instance, the section Halmaturus: 
but of the several species of Halmaturus , or Brush-Kangaroos, 
inhabiting that portion of Australia, we learn from Mr. Gould 
that they each affect different minor districts. Some are fitted 
for one kind of scrub, and some for another; some prefer the 
swamps, and others the high table land; such a difference of 
habits is observed in the two species which are most nearly 
equal in size and power—the H. ualabatus and the H. 
riificollis of Gould. 
Viewing the Marsupialia as an order, it is one which presents 
a remarkable diversity of structure (and, consequently, habits), 
containing herbivorous, carnivorous, and insectivorous species: 
indeed, we find amongst the marsupial mammals analogous 
representations of most of the other orders of Mammalia. The 
Quadrumana tire represented by the Phalangers, the Carni¬ 
vora by the Dasyuri, the Insectivora by the small Phascogalcs, 
the Rumman tia by the Kangaroos, and the Edentata by the 
Monotremcs. The Cheiroptera are not represented by any 
known marsupial animals, and the Rodents are represented 
by a single species only; the hiatus is filled up, however, in 
both cases, by placental species, for both Bats and Rodents 
are tolerably numerous in Australia, and, if wc except the 
dog, which it is probable lias been introduced by man, these 
are the only placental mammalia found in that continent. 
The most striking peculiarity in the marsupial animals 
consists in the premature birth of their young, aud conse¬ 
quently the imperfect state of development which they 
