3 
Family Rodentia (Hat tribe). 
From six to ten species of fossil rodents have been discovered, all of which differ much in their dentition 
from other Rats, but resemble some living' Australian species. 
ORDER MARSUPIALIA. 
Family Phascolomyidie ( Wombat tribe). 
Twenty fossil species, including the four still living- ones. 
Family Piialangistidje (Hhalanger tribe). 
Phalangers, Native Bears, Flying Squirrels, &c., from fifteen to twenty gigantic species, including the 
genera Biprotodon, Nototherium,* Zygoma turns, and Thylacoleo ; all of which are classed with the Phalangers, which 
they resembled in the structure of their limbs and in the position and function of their teeth. 
Family Macuopodiile ( Kangaroo tribe). 
Together about fifty fossil species, some of which are still living. 
All the gigantic Kangaroos, with short and stout tarsal bones, are now extinct. 
Family Pebameliile (Bandicoot tribe). 
About five or six fossil species, which cannot be distinguished from living ones. 
Family Dasyekedab ( Native Gat tribe). 
Four large and as many small species, the latter identical with living ones. Two large Dasyures, the 
Thylacinus and Sarcophilus , still exist in Tasmania, but are extinct on the mainland. 
Section Monothemata (Ant-eater and Buck-bill tribe). 
One or two species of the Echidna probably existed; remains of the Platypus have not yet been found. 
* The two genera Nototherium and Zygomaturus which Professor Owen considers to be identical, differ principally in the form of their molar teeth. The first genus is founded 
upon nothing but lower jaws, the grinders of which resemble in their horizontal section, at the base of the crown, a loop or the figure co , but less contracted in the middle ; 
the last grinder is always the largest. The genus Zygomaturus, founded on a perfect skull, possesses teeth a section of which at their base would form a square, the last hit one 
being the largest tooth of the series. I have classed all the large genera (Diprotodon, Nototherium , and Zygomaturus) with the Phalangers, because like these their teeth are inserted 
by tapering fangs. The Kangaroos and Wallabies have molar teeth — the fangs of which enlarge at the end, and, in aged animals, grow into the substance of the jaw, so that their 
removal is impossible without breaking the bone. The Wombats, again, possess teeth without roots, differing in their shape from both the Phalangers and the Kangaroos, and closely 
resembling the teeth of certain rodents. 
