In the size and admeasurements of the various parts of either sex of the white and grey birds no difference whatever can be detected, another reason for believing them to be the same; for wherever a specific difference is found to exist, it is always accompanied by a difference in the dimensions of the whole or parts of the structure. A knowledge of the nidification of this and the preceding bird, and of the state of their plumage from youth to maturity, would greatly tend to settle the question of their identity. The disposition of Mr. Elliot’s bird was fierce and wild in the extreme, exhibiting none of the docility of the true Falcons, but displaying all the ferocity so characteristic of the group to which it belongs. The sexes differ very considerably in size, the male being scarcely more than half the size of the female. The whole of the plumage pure white; cere and legs yellow; bill and claws black. The figures represent the two sexes of the natural size. [Illustration: ASTUR RADIATUS. _J. Gould and H. C. Richter del et lith._ _C. Hullmandel Imp._ ] ASTUR RADIATUS. Radiated Goshawk. _Falco radiatus_, Lath. Ind. Orn. Supp., p. xii.—Shaw, Gen. Zool., vol. vii. p. 177. _Radiated Falcon_, Lath. Gen. Syn. Supp., vol. ii. p. 53. pl. cxxi.—Ib. Gen. Hist., vol. i. p. 222. pl. xi. _Haliaëtus Calei_, Vig. and Horsf. in Linn. Trans., vol. xv. p. 186. The bird here represented I conceive to be the true _Falco radiatus_ of Latham; it is but little known to ornithologists, from the circumstance that few specimens only have been sent to Europe. It inhabits the dense brushes bordering the rivers Manning and Clarence on the eastern coast of New South Wales, and doubtless enjoys a much greater range than we are at present acquainted with. It is the largest of the Goshawks inhabiting Australia, far exceeding in size the _Astur palumbarius_ of Europe. In some parts of its structure it differs considerably from the typical Asturs, particularly in the lengthened form of the middle toe, in which respect it resembles the true Accipiters; in its plumage it somewhat differs from both those forms, the markings of most of the feathers taking a longitudinal instead of a transverse direction; these differences may hereafter be considered of sufficient importance to warrant its separation into a distinct genus, but for the present I have retained it with the other Goshawks in that of _Astur_. Of its habits and economy nothing whatever is known.