HALMATURUS DERBIANUS, Gray. Derby’s Wallaby. Face anp Fore Part or a Mate ANnpD or A FEMALE, OF THE NATURAL SIZE. My figures of this animal were taken from specimens procured on Kangaroo Island, at oiven the name the entrance of Spencer’s Gulf. I mention this particularly, because I have g of Halmaturus Houtmanni to an animal inhabiting the Abrolhos of Western Australia, which Mr. Waterhouse considers may be only a variety of the present species; but this is a pomt which time alone can determime. These insular animals are extremely puzzling, and con- siderable judgment is required in ascertaining their specific value. The Halmaturus Derbianus is somewhat allied to the H. Parma; still they are unques- tionably distinct. They form, with H. dorsalis, a little section of the group quite different from that constituted by H. Thetidis, H. stigmaticus, H. Billardieri, and H. brachyurus. The H. Derbianus is very numerous in all the thick brushes of the islands on which it has been found. It is bustling and quick in all its actions; and it is only by the aid of dogs that it can be forced from its retreat, or to leave the numerous runs formed by it beneath the underwood in all directions. For the pleasing life-like representation of this species, much credit is due to Mr. Richter ; for nothing could be more faithful. The reader is referred to the description accompanying the reduced figures given on the next Plate for a full account of this animal. a ene