CALYPTORHYNCHUS MACRORHYNCHUS, Gow. 
Great-billed Black Cockatoo. 
Calyptorhynchus macrorhynchus, Gould in Proc. of Zool. Soc., Part X. p. 138. 
Lay-a-wuk, Natives of Taratong. 
Aut the examples of this species that haye come under my notice have been collected at Port Essington, 
where it is usually seen im small troops of from four to six im number. It has many characters in common 
with the Black Cockatoos of the south coast, but no species of the genus yet discovered has the bill so 
largely developed, which development is doubtless requisite to enable it to procure some peculiar kind of 
food at present unknown to us; it assimilates to the C. Cookii of New South Wales in the lengthened form 
of its crest, but differs in having much shorter wings, and in the mandibles being fully one-third larger. 
The females of the two species also vary considerably in the colouring of the bands across the tail- 
feathers, which in the ©. Cookic is pure scarlet, while the same part of the female of the present bird is 
mingled yellow and scarlet. It differs from the C. xaso of Western Australia in having a larger bill than 
that species, and in the much greater length of the crest; a similar difference is also observable in the 
colouring of the tail-feathers of the females that has been already pointed out with regard to C. Cookii. 
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 par- 
ticularly the chest, crossed by several semicircular fascia 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 sur- 
face 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 ; rides blackish brown. 
The Plate represents the two sexes about two-thirds of the natural size, 
