The colouring of the sexes when fully adult is alike, but much variation exists between youth and maturity; during the first autumn the young birds are clothed in a plumage of a nearly uniform green; to this succeeds a parti-coloured livery of scarlet, blue and green, which colouring is continually changing until the full plumage of maturity is assumed; and hence has arisen no little confusion respecting this species in the writings of the older ornithologists, and it is not to be wondered at that its synonyms are so numerous. The adult male has the head, neck, all the under surface, the rump and upper tail-coverts rich deep crimson-red; the feathers of the back and scapularies black, broadly margined with rich crimson-red; the cheeks and shoulders cœrulean blue; the greater wing-coverts pale blue; the primaries and secondaries black, with the basal half of their external webs margined with deep blue; the two centre tail-feathers green, passing into blue on their margins and at the tip; the remainder black on the inner webs for three-fourths of their length; deep blue for nearly the same length on their outer webs, and largely tipped on both webs with pale blue, which becomes still paler to the tips of the feathers; bill horn-colour; irides very dark brown; feet blackish brown. The young vary so much, that to give an accurate description is almost impossible; one now before me has the crown of the head, sides of the neck, centre of the breast, abdomen, rump, upper and under tail-coverts deep crimson-red; the upper surface and a broad band across the breast deep grass-green; the cheeks, wings and tail similar to those parts in the adult, but much less brilliant. The Plate represents an adult and an immature bird of the natural size. [Illustration: PLATYCERCUS FLAVIVENTRIS. _J. Gould and H.C. Richter del et lith._ _Hullmandel & Walton Imp._ ] PLATYCERCUS FLAVIVENTRIS. Yellow-bellied Parrakeet. _Psittacus flaviventris_, Temm. in Linn. Trans., vol. xiii. pp. 116–118. ———— _Brownii_, Kuhl, Nova Acta, etc., vol. x. p. 56. no. 90. _Perruche à large queue_, Le Vaill. Hist. Nat. des Perr., pl. 80. _Van Diemen’s Parrot?_, Lath. Gen. Hist., vol. ii. p. 130. no. 33. _Platycercus flaviventris_, Vig. and Horsf. in Linn. Trans., vol. xv. p. 281.—Gould in Syn. Birds of Australia, Part II. _Sulphur-headed Parrot?_, Lath. Gen. Hist., vol. ii. p. 133. no. 35. _New Caledonian Parrot?_, Lath. Ib., vol. ii. p. 173. no. 86. _Psittacus Caledonicus?_, Lath. Ind. Orn., vol. i. p. 102.—Gmel. Linn., vol. i. p. 328. _Caledonian Parrot?_, Lath. Gen. Syn., vol. i. p. 248. _Green Parrot_, Colonists of Van Diemen’s Land.