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Show 428 MR. H. O. FORBES ON BIRDS F R O M [June 17, tbe paler bluish-grey attire." I feel satisfied, after examining specimens in the British Museum and in my own collection, that the difference in coloration is one due to age, for in young birds the plumage is lighter than in the adult state. Dr. Meyer's observation that the dark mantle reaches, in Timor-Laut skins only, just to the root of the tail, while in A. leucogaster it overlaps by about 1 centimetre, is, in as far as the series referred to enables an opinion to be formed, one not sufficiently constant to support specific separation. In several Timor-Laut specimens examined the dark plumage overlaps the tail more than 1 centimetre, and even more than in others from different parts of the Archipelago which have been hitherto recognized as A. leucogaster. In skins of A. leucogaster from Mysol and Macassar, the mantle is just conterminous with the root of the tail. Really, however, the absolute constancy of these measurements can be determined only with accuracy in the flesh, for the way in which the skin is manipulated will increase or diminish them by several centimetres. The same holds with regard to another character given as differential-the greater amount, in Timor-Laut specimens, of white on the rump and upper tail-coverts. In my own specimens the white on the rump varies from 22-31 millim. in length, while in eight other skins from different regions of the Archipelago the range is from 26-32 millim., giving in the latter, indeed, a wider zone than in those from Timor-Laut. In the long series of British-Museum skins, the white tips of all but the two middle tail-feathers, another of Dr. Meyer's differential characters, is also quite inconstant. In several Timor-Laut skins not only these two tail-feathers, but several others of the remiges, are without a white band, while in some examples it is even less than in undisputed A. leucogaster. In young birds the white tips are very pronounced, not on the remiges only, but on the primaries and secondaries of the wing also. The Philippine (Zebu) birds, already referred to, have the tips of the remiges quite as broad as in those from Timor-Laut. In a Lombock specimen (" ex Stevens ") the tips of all the feathers are white ; a Batanta and a New-Holland specimen have no white tips at all; one from Halmaheira and one from Buru (both from Mr. Wallace's collection), except in one feather, have no white on the remiges ; yet all of them have been determined to be, and are undoubtedly A. leucogaster (Val.). As to the species of Pachycephala (arctitorquis, Sclater) from Timor-Laut, we have the curious fact that, notwithstanding my more thorough examination of a wider field, the whole series obtained by me contained, if Dr. Meyer is correct in his determinations, no females of P. arctitorquis and no males of P. riedelii (were Dr. Meyer's specimens sexed ?) ; while those who made the collection examined by Dr. Meyer obtained in Babbar (an island at no great distance to the W . of Yamdena) females of P. arctitorquis, and evidently no males (so recognized by Dr. Meyer), and females of P. kibirensis (Meyer), without one of its males. I daily saw the collections made in Timor-Laut by the Amboinese hunters above mentioned, and I feel confident that no species of |