Petaurus breviceps.
This is probably the species called P.peronii in Mr.G.Bennett's catalogue of the Australian Museum.

It may also be M.Desmarest's; if this is so, the latter name will have to be adopted, and the one first used erased from the list.
Number 47.
The Macropi with hairy muffles are found in grassy places, while the Halmaturi are confined to the scrubs; and the Petrogalae, or Rock-Kangaroos, to the rocky districts; the latter, like Bettongia, sit with their tail between the legs.

Mr.Gould informs me the animals of the latter genus also use their tails for the purpose of carrying the grass to their nests.

The tree Kangaroos of New Guinea have a tail somewhat like a squirrel.

These differences of habit show the propriety of dividing this group of animals into genera.
Number 48.