It is a very powerful species, and its habits and economy are so similar to the other members of the genus that a description of them would be superfluous. The male has the whole of the plumage glossy bluish black; lateral tail-feathers, except the external web of the outer one, crossed by a broad band of fine scarlet; bill horn-colour; irides blackish brown; feet mealy blackish brown. The female has the general plumage as in the male, but with the crest-feathers, those on the sides of the face and neck, and the wing-coverts spotted with light yellow; each feather of the under surface, but particularly the chest, crossed by several semicircular fasciæ of yellowish buff; lateral tail-feathers crossed on the under surface by numerous irregular bands of dull yellow, which are broad and freckled with black at the base of the tail, and become narrower and more irregular as they approach the tip; on the upper surface of the tail these bands are bright yellow at the base of the feathers, and gradually change into pale scarlet as they approach the tip; irides blackish brown. The Plate represents the two sexes about two-thirds of the natural size. [Illustration: CALYPTORHYNCHUS NASO: _Gould_ _J. Gould and H.C. Richter del et lith._ _Hullmandel & Walton Imp._ ] CALYPTORHYNCHUS NASO, _Gould_. Western Black Cockatoo. _Calyptorhynchus naso_, Gould in Proc. of Zool. Soc., Part IV. p. 106. _Kar-rak_, Aborigines of the mountain and lowland, and _Keer-jan-dee_ of the Aborigines of the northern districts of Western Australia. _Red-tailed Black Cockatoo_ of the Colonists. The characters by which this species is distinguished from the _Calyptorhynchus macrorhynchus_, are a smaller bill and a shorter and more rounded crest; the same characters, which I know to be constant, also distinguish it from the _C. Banksii_. The bill is inclined to be gibbose, like that of _C. Leachii_, to which species it also offers a further alliance in its shorter contour, rounded crest, and short tail. The extent of range enjoyed by the _Calyptorhynchus naso_ I have not been able to ascertain; its great stronghold appears to be the colony of Swan River, where it inhabits all parts of the country. As might be expected, its habits and economy closely resemble those of the other members of the genus. Except in the breeding-season, when it pairs, it may often be observed in companies of from six to fifteen in number. It breeds in the holes of trees, making no nest, but merely collecting the soft dead wood on which to deposit its eggs, which are generally placed in trees so difficult of access that even the natives dislike to climb them. The eggs are four or five in number; the four given to Mr. Gilbert by the son of the colonial chaplain were taken by a native from a hole in a very high white gum-tree, in the last week of October; they are white, one inch and eight lines long by one inch and four lines broad.