OCR Text |
Show 1882.] MR. W. A. FORBES ON THE GENUS ORTHONYX. 545 In Orthonyx ochrocephala the left carotid retains its normal situation, though the point of entrance into the canal is somewhat higher up than is usual in other Passeres. Examination of m y spirit-specimens of these two birds has convinced me that the two forms are not really congeneric, the New- Zealand bird (O. ochrocephala) differing from the Australian in its more slender bill, less development of the nasal operculum, less spiny tail, and more slender claws. The coloration of the two forms is quite unlike; whilst internally the skull and syrinx exhibit differences, slight in amount, but greater than those usually found in birds of the same genus. Under these circumstances it seems that Clitonyx of Reichenbach * will be the correct generic term for the New-Zealand birds, as Lesson's name Mohoua, though of prior application2, is not only barbarous but, what is more important, liable to be confounded with Mohoa, also a genus of Passeres from the Pacific Subregion. In the present unsatisfactory condition of the systematic grouping oftheOscinine Passeres, it is impossible for me to point out clearly anv definite position either for Orthonyx or Clitonyx, though both forms might, I apprehend, be safely placed in Mr. Sharpe's somewhat vaguely-defined " Timeliidae." The determination of the not-intimate relation of Orthonyx to Clitonyx is a point of some importance, from its bearing on the question of the general relationships of the fauna of N e w Zealand to that of Australia, Orthonyx having been sometimes mentioned as one of the few peculiar Australian genera of birds also represented in the satellite island 3. I may take this opportunity of stating that I have, in the course of the last few months, been enabled to examine examples of several genera of Passeres the condition of the syrinx in which has not before, I believe, been recorded. These include, of Old-World forms, Ri-mator, Ptenadus, Sphenura, Sphenostoma, Climacteris, Creadion, Miro, Certhiparus, Petrceca, Entomyza, Pomarea, Phceornis, Fal-cunculus, Nesocichla, Nesospiza, Cracticus; and of American forms, Chamcea, Bulus, Phainopepla, Ptilogonys. In all these genera the syrinx is perfectly Oscinine, as indeed was to be expected from the external structure of the birds. Johannes Miiller at first placed Ptilogonys amongst the Tyrannidae4, misled by the slightly aberrant structure of its tarsus, but on subsequently examining the nearly allied Myiadestes, and ascertaining its Oscinine nature, concluded that Ptilogonys too would, on examination, be found to have the muscular organs of voice5, a surmise the correctness of which is now demonstrated. Petrceca has been stated by Prof. Parker6 to be a " Tra- 1 Handb. Spec. Ornith. p. 167 (1851).^ 2 Hist. Natur. Oiseaux, iii. p. 139 (1837). 3 Wallace, ' G-eogr. Distribution of Animals,' i. p. 451; but see also ' Island Life,' p. 453, footnote. 4 Vocal Organs of Passeres, Garrod's ed. p. 41. s L.c. p. 61. B Trans. Z. S. ix. p. 336. |