Length, body and head 6, tail 4 3/4, hind-feet 1 1/12 of an inch.
Number 86.

Mus adelaidensis.
Fur soft, brown, with scattered rather longer black tipped hairs, beneath pale grey brown; the under fur lead coloured; whiskers black; ears moderate, covered with short close-pressed hairs; tail elongate, brown; cutting teeth pale yellow, compressed; body and head 3, tail 3 inches, hind-feet 8-12.

Inhabits South Australia.

J.Gould, Esquire.
In examining the Geographical distribution of the Genera, as exhibited in the foregoing table, as far as our present knowledge of these animals extends we may state that the genera Choeropus, Acrobates, Petaurista, Lagorchestes, Phascolarctos, Hapalotis, and Pseudomys, are peculiar to New South Wales.

The genus Petaurus is also found in New South Wales, but not in the Island of Van Diemen's Land and the rest of the continent, but one of the species living there is also said to be an inhabitant of Norfolk Island, where it may probably have been introduced.
The species of the genera Petrogale and Bettongia are common to New South Wales, South Australia, and the North-west Coast; but they are not found in Van Diemen's Land, and the genus Myrmecobius appears to be peculiar to Western Australia, for it is not by any means certain that the red shrew-mouse discovered in Australia Felix by Sir T.Mitchell belongs to this genus.
The Genera Thylacinus, Diabolus, and Dromicia, are peculiar to Van Diemen's Land.
The species of the genera Dasyurus and Perameles are very abundant in Van Diemen's Land, but they have also representatives which are found in New Holland.
The species of the genera Nyctophilus, Phalangista, Hepoona, Phascogale, Macropus, Halmaturus, Hypsiprymnus, and Hydromys, appear to be common to all parts of the continent, and also to Van Diemen's Land.
The genera Echidna and Ornithorhynchus are found in New Holland and Van Diemen's Land, but I have not heard of their having been discovered in the Western or Southern parts of the continent of Australia.
There are some of the genera of the non-Marsupial animals, as Rhinolophus and Pteropus, which are common to various parts of Australia and the different parts of the Old World, and others, as Canis, Mus, Scotophilus, and Molossus, which are common to it and to both Hemispheres.