_J. Gould and H. C. Richter del et lith._ _Hullmandel & Walton Imp._ ] PETROICA ERYTHROGASTRA. Norfolk Island Robin. _Muscicapa erythrogastra_, Lath. Ind. Orn., vol. ii. p. 479.—Gmel. Syst. Nat., vol. i. p. 944. —— _multicolor_, Gmel. Syst. Nat., vol. i. p. 944. _Red-bellied Flycatcher_, Lath. Gen. Syn., vol. iii. p. 343. pl. 50.—Ib. Supp., vol. ii. p. 216.—Shaw, Gen. Zool., vol. x. p. 400. pl. 32.—Lath. Gen. Hist., vol. vi. p. 209. pl. C.—Shaw, Nat. Misc., pl. 147. _Petroica pulchella_, Gould in Proc. of Zool. Soc., Part VII. p. 142, male. —— _modesta_, Gould in Proc. of Zool. Soc., Part V. p. 147, female. I have been induced to give a figure of this Robin, which I believe to be strictly confined to Norfolk Island, in order to clear up the confusion which has hitherto existed respecting it and the _Petroica multicolor_, with which it has been confounded. Under the impression that the two birds were identical, and that the terms _erythrogastra_ and _multicolor_ were synonymous, I was induced some years ago to characterize the male of the present bird under the name of _pulchella_, and the female under that of _modesta_, believing as I then did that it was a distinct species; subsequent research has however enabled me to perceive the errors into which I had fallen, and I now proceed to point out the differences between the two species, and to restore to the Norfolk Island bird the term _erythrogastra_, originally applied to it by Latham. The _P. erythrogastra_ may be distinguished then from its near ally by the greater size of the bill; by the greater extent and more silvery hue of the white feathers on the forehead; by the tail being wholly black, while in the _P. multicolor_ the lateral feathers are white; by the white on the wing forming a large spot near the shoulder, instead of a line as long as the secondaries; and by the scarlet of the breast and abdomen being much more intense in colour: the females of the two birds also differ from each other, the tail of the _P. erythrogastra_ being wholly brown, while that of the _P. multicolor_ has the lateral tail-feathers marked with white. The male has the forehead silvery white; a small patch on the wings near the shoulder, under wing-coverts, the flanks and under tail-coverts white; chest and abdomen very rich scarlet, the remainder of the plumage deep black; bill black; feet brown. The female has the crown of the head, all the upper surface, wings and tail reddish brown; throat white, tinged with brown; chest and centre of the abdomen washed with scarlet; lower part of the abdomen and under tail-coverts white; flanks brown; bill blackish brown; feet yellowish brown. The figures represent the two sexes of the natural size. [Illustration: PETROICA GOODENOVII: _Jard. and Selb._ _J. Gould and H. C. Richter del^t._ _C. Hullmandel Imp._ ]