of Swan River is one of the oldest known; the L. Leichardti the latest yet discovered.
The Bettongiæ, with their singular prehensile tails, also enjoy a wide range, the various species composing the genus being found in Tasmania, New South Wales, Southern and Western Australia, but, so far as we yet know, not in the north. For a more detailed account of the localities favoured with the presence of these animals, and the manner in which their prehensile tails are employed in carrying the grass for their nest, I must refer to the history of the respective species, and particularly to the plate of Bettongia cuniculus.
The Hypsiprymni are the least and, perhaps, the most aberrant group of this extensive family. They inhabit the southern and most humid parts of the country, and are to be found everywhere, from Tasmania to the 15th degree of latitude on the continent in one direction, and from the scrubs of Swan River and King George's Sound to the dense brushes of Moreton Bay in the other; like most other Kangaroos, they are nocturnal in their habits, grub the ground for roots, and live somewhat after the manner of the Peramelides, with which, however, they have no relationship.
To render my history of this group of animals the more complete, I have included in the work the three species inhabiting New Guinea: two of these belong to the genus Dendrolagus, and, as their name implies, dwell among the branches of trees, and rarely resort to the ground: the third forms the genus Dorcopsis, of which a single species only is known; it has doubtless some peculiar habits; but these must be left for a future historian to describe; at present they are unknown.
The great family of the Kangaroos, of which what I have here written must only be regarded as a slight sketch, is well worthy the study of every mammalogist. It forms by far the most conspicuous feature in the history of Australian quadrupeds; and, numerous as are the species now known, I doubt not that others will yet be discovered when the north and north-
