In one of the specimens I possess, and which formed the subject of the upper figure in the Plate, no trace of the nuchal ornament is observable, a circumstance I conceive to be indicative of youth rather than a distinguishing characteristic of the sexes, since in the other species I find the mark common to both, but the young bird of the year without any trace of it. The Plate represents a male and a young bird, of the natural size. [Illustration: PTILONORHYNCHUS HOLOSERICEUS: _Kuhl_ _J. & E. Gould del et lith._ _C. Hullmandel Imp._ ] PTILONORHYNCHUS HOLOSERICEUS, _Kuhl_. Satin Bower-bird. _Ptilonorhynchus holosericeus_, Kuhl, Beytr. zur Zool. S. 150.—Wagl. Syst. Av. sp. 1.—G. R. Gray, Gen. of Birds, p. 40.—Swains. Class. of Birds, vol. ii. p. 271. _Pyrrhocorax violaceus_, Vieill. Nouv. Diet. d’Hist. Nat., tom. vi. p. 569.—Ib. Ency. Méth. 1823, p. 896. _Kitta holosericea_, Temm. Pl. Col. 395 and 422.—Less. Traité d’Orn., p. 350, pl. 46. fig. 1. _Satin Grakle_, Lath. Gen. Hist., vol. iii. p. 171. _Ptilonorhynchus MacLeayii_, Lath. MSS., Vig. and Horsf. in Linn. Trans., vol. xv. p. 263. _Corvus squamulosus_, Ill., female or young? Ptilonorhynchus squamulosus, Wagl. Syst. Av. sp. 2, female or young? _Satin Bird_, of the Colonists of New South Wales. _Cowry_, of the Aborigines of the coast of New South Wales. Although this species has been long known to ornithologists, and is familiar to the colonists of New South Wales, its habits, which in many respects are most extraordinary, have hitherto escaped attention; or if not entirely so, have never been brought before the scientific world. It is, therefore, a source of high gratification to myself to be the first to place them on record. One point to which I more particularly allude,—a point of no ordinary interest, both to the naturalist and the general admirer of nature,—is the formation of a bower-like structure by this bird for the purpose of a playing-ground or hall of assembly, a circumstance in its economy which adds another to the many anomalies connected with the Fauna of Australia. The localities favourable to the habits of the Satin Bower-bird are the luxuriant and thickly-foliaged brushes stretching along the coast from Port Philip to Moreton Bay, the cedar brushes of the Liverpool range, and most of the gullies of the great mountain-chain separating the colony from the interior. So far as is at present known, it is restricted to New South Wales; certainly it is not found so far to the westward as South Australia, and I am not aware of its having been seen on the north coast; but its range in that direction can only be determined by future research.