Crown of the head, lores and ear-coverts deep black; cheeks snow-white, bounded below with blue; breast and rump pale yellow, each feather slightly fringed with black; feathers of the back deep black, with a broad margin of pale yellow; wing-coverts, outer webs of the secondaries and base of the primaries rich blue, inner webs of the primaries and secondaries deep black; under tail-coverts scarlet; centre tail-feathers green at the base, passing into blue on the margins and at the tip; lateral feathers deep blue at the base of the outer webs, brown at the base of the inner webs, and then pale blue terminating in white, with black shafts; irides blackish brown; bill light horn-colour, passing into blue at the base; legs and feet blackish brown. Young birds are similar in colour, but have all the markings dull and indistinct; as the individual approaches to maturity the breast becomes ornamented with a number of crescent-shaped markings of black and pale yellow, and as the bird advances in age the yellow increases in extent and the black nearly disappears. The three figures in the Plate represent two males and a female; the crimson-headed bird drawn from a specimen collected on the north-west coast, and the other male from one procured at Port Essington; they are all of the natural size. [Illustration: PLATYCERCUS PILEATUS: _Vig._ _J. Gould and H.C. Richter del et lith._ _Hullmandel & Walton Imp._ ] PLATYCERCUS PILEATUS, _Vig._ Red-capped Parrakeet. _Platycercus pileatus_, Vig. in Zool. Journ., vol. v. p. 274.—Lear’s Ill. Psitt., pls. 21 and 22.—Wagl. Mon. Psitt. in Abhand., pp. 491 and 528. _Psittacus purpureocephalus_, Quoy et Gaim. Voy. de l’Astrolabe, pl. 22. _Djȁr-rail-bȕr-tang_, Aborigines of the lowland districts of Western Australia. _Blue Parrot_ of the Colonists. The _Platycercus pileatus_ differs so much in the colouring of its plumage from every other species of the great family of Parrots, as to render it one of the most remarkable yet discovered; in the form and structure of its bill there is also a remarkable deviation from the true _Platycerci_, and it will probably be hereafter found that this modification of its form is adapted to some especial purpose, in which case this bird might with propriety constitute the type of a separate genus; in the absence, however, of all information respecting its habits and economy, I prefer retaining it in the genus in which it was placed by Mr. Vigors, its first describer.