Page:The Emu volume 3.djvu/121

 of the chief characteristics of the adult female and the young of both sexes of G. dorsalis.

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During the systematic examination mentioned I handled some 22 skins of this species, of both sexes, and both adult and young, procured in different parts of the State, and propose to now record the results of my observations. These do not wholly support or confirm the several distinctions made by Mr. Campbell in separating the species from the Gymnorhina leuconota (Gould), but nevertheless they must not be taken as challenging the validity of the species (for I consider it a firm one), but as for better information.

Mr. Campbell's distinctions, shortly stated, are as follows:— (a) Smaller in size than Gymnorhina leuconota; (b) bill more narrow and longer; (c) wing edges mottled instead of white; and (d) black terminal tail-band more narrow and concentric.

Dealing with the first distinction, I measured the skins of seven males, in which the measurements in inches from base of skull to tip of tail and from base of skull to point of mandibles (over all) were respectively as follow:—13 × 4, 13⅞ × 4¼, 13¼ × 4¼, 13¼ × 4¼, 13¼ × 4, 13 × 4¼, 13⅞ × 4⅛. As I have not similar measurements of a series of Gymnorhina leuconota, I am unable to make a comparison, but from a long acquaintance with each in its own habitat I do not hesitate to say that the Western form is a more robust and longer bird. As regards the second point of distinction, Mr. Campbell is undoubtedly correct, for the bill is more narrow and longer. In six of the males referred to the measurements in inches of the culmen were 2.25, 2.4, 2.4, 2.25, 2.4, 2.4, and 2.5. Respecting the third point, I am unable to agree with Mr. Campbell, as in every instance I found the wing edge white, but not mottled. I confirm the fourth distinction, for the terminal tailband is as a rule more narrow and concentric. The narrowness of the band is, however, purely a matter of age. For instance, in two adult males in full and mature plumage the tail-band measured 1 inch and ⅞ of an inch respectively, while in another adult bird, who had almost attained full and mature plumage, the same band was 1¼ inches, while in three other younger birds the bands were 1¾, 1⅜, and 1⅜ inches respectively.

Another noteworthy feature in connection with the tails of the Western species is the relative colouring of the stems of the tail feathers. In the two oldest birds mentioned these stems were white to the extent of the white bands, and black to the extent of the terminal black band. In the adult male, which had almost attained full plumage, the stems of the white-coloured portion of the tail were partially black and partially white, and in the younger birds the stems were wholly black for the whole length of the stem.

The same remarks apply with equal force to Gymnorhina longiroslris, just described. The size of the white vent-patch also