For a knowledge of this new species of Grass-Parrakeet, the scientific world is indebted to Major Sir T. L. Mitchell, who discovered it on the banks of the River Bogan, during one of his expeditions into the interior of New South Wales. It is particularly interesting, as exhibiting in the crescentic form of the markings on the back, an approach to the style of colouring observable in the single species of the genus _Melopsittacus_ (_M. undulatus_); at the same time, in its structure it so closely assimilates to the form of the genus _Euphema_, that I have been induced to place it in that group. It must be regarded as a bird of the greatest rarity, since I did not meet with it during my own expedition, nor could I gain any information whatever respecting it; it is therefore another of those Australian birds to which I would direct the attention of the travellers who may hereafter visit the interior, of which it will doubtless prove to be a denizen. The two examples obtained by Sir T. L. Mitchell are deposited in the Museum at Sydney, and from them the accompanying figures were taken. Band across the forehead, shoulders above and beneath, secondaries and base of the primaries deep blue; flanks and under tail-coverts turquoise-blue; all the upper surface dark olive-brown, the feathers of the wings edged with greyish white; centre of the abdomen salmon-red; cheeks and remainder of the under surface brown, strongly tinged with salmon-red; six middle tail-feathers deep brown, the external webs tinged with blue; the three outer ones on each side brown at the base, with their external webs blue and the tips white; bill dark horn-colour; legs brown. The figures are of the natural size. [Illustration: MELOPSITTACUS UNDULATUS. _J. & E. Gould del._ _C. Hullmandel Imp._ ] MELOPSITTACUS UNDULATUS. Warbling Grass-Parrakeet. _Psittacus undulatus_, Shaw, Nat. Misc., pl. 673.—Kuhl, Consp. Psitt. in Nova Acta, &c., vol. x. p. 49. _Undulated Parrot_, Lath. Gen. Hist., vol. ii. p. 179, pl. xxvi. _Undulated Parrakeet_, _Psittacus undulatus_, Shaw, Gen. Zool., vol. viii. p. 469. _Nanodes undulatus_, Vig. and Horsf. in Linn. Trans., vol. xv. p. 277.—Steph. Cont. of Shaw’s Gen. Zool., vol. xiv. p. 119.—Lear’s Ill. Psitt., pl. 13.—Selby, Nat. Lib., Parrots, p. 181, pl. 19. _Euphema undulata_, Wagl. Mon. Psitt. in Abhand., &c., pp. 493, 545, and 707. _Canary Parrot_, Colonists. _Betcherrygah_, Natives of Liverpool Plains.