1882.] MR. W. A. FORBES ON THE GENUS ORTHONYX. 545 
In Orthonyx ochrocephala the left carotid retains its normal sit- 
uation, though the point of entrance into the canal is somewhat 
higher up than is usual in other Passeres. 
Examination of my spirit-specimens of these two birds has _con- 
vinced 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 dif- 
ferences, 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 appli- 
cation’, is not only barbarous but, what is more important, liable to be 
confounded with Mohoa, also a genus of Passeres from the Pacitic 
Subregion. 
In the present unsatisfactory condition of the systematic grouping 
ofthe Oscinine Passeres, it is impossible for me to point out clearly any 
definite position either for Orthonyx or Clitonyx, though both torms 
might, I apprehend, be safely placed in Mr. Sharpe’s somewhat 
vaguely-defined ‘ Timeliidee.”’ 
The determination of the not-intimate relation of Orthonyz to 
Clitonyx is a point of some importance, from its bearing on the 
question of the general relationships of the fauna of New Zealand 
to that of Australia, Orthonya having been sometimes mentioned 
as one of the few peculiar Australian genera of birds also repre- 
sented in the satellite island *. 
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, Petreeca, Entomyza, Pomarea, Phcornis, Fal- 
cunculus, Nesocichla, Nesospiza, Cracticus; and of American forms, 
Chameea, Dulus, 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 Tyrannide *, 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 voice’, a surmise the correctness of which is now demon- 
strated. Petreca has been stated by Prof. Parker ® to be a “ Tra- 
1 Handb. Spec. Ornith. p. 167 (1851). 
2 Hist. Natur. Oiseaux, ili. p. 139 (1837). 
3 Wallace, ‘Geogr. Distribution of Animals,’ i. p. 451; but see also ‘Island 
Life,’ p. 453, footnote. 
4 Vocal Organs of Passeres, Garrod’s ed. p. 41. 
5 Lic. p. 61. 
6 Trans. Z, 8. ix. p. 336, 
