ON THE GENUS ORTHONYX. 357 



and fltxor profundus diyitorum blend together towards the lower part of 

 the tarso-metatarse, a comparatively very insignificant tendinous slip 

 being given off from the tendon of the first-named muscle to the hallux 

 before it blends with the other *. In Biziura the two tendons com- 

 pletely blend, but the small tendinous slip, given off, as usual, before they 

 unite, does not go to the liallux as it normally does, but continues down 

 to the bottom of the bone, and is there lost on one of the annular masses 

 of fibro-cartilage surrounding the other flexor tendons. The flexor brevis p.z. S. 1882, 

 hallucis, which is present, though small, is thus the only functional flexor P- 468 - 

 of that digit. 



62. CONTRIBUTIONS TO THE ANATOMY OF PAS- p.z. s. 1882, 

 SERINE BIRDS. PART V.f ON THE STRUCTURE P- 644 

 OF THE GENUS ORTHONYX. } 



THE position in the series of Passeres of the genus Orihonyx has for 

 many years been a moot point with ornithologists, Johannes Miiller 

 having long ago surmised that these birds might be tracheophonns, and 

 so connected with the Neotropical DendrocolapticUe. Some recent writers 

 (e. g. G. R. Gray, Bonaparte, and Salvador!) have placed them in, or in 

 the neighbourhood of, the Menuridse ; Sundevall, on the other hand |J, 

 assigns them a position amongst his Cichlomorpha3 Brevipennes. 



Up to the present time the formation of their soft parts, and particu- 

 larly of the syrinx, has remained unknown a deficiency in our knowledge 

 I am now able to supply by my dissection of both the Australian and 

 New-Zealand forms. For my specimens of the former (Orthonyx spini- 

 cauda) I am indebted to the kindness of Mr. E. P. Ramsay, of the 

 Australian Museum ; for a pair of the latter (0. ochrocephafa) to that of 

 my friend Prof. Jeffery Parker, of the University of Otago. 



Both forms are typical Singing-birds (" Osciues Normales "), with a 

 well-developed Oscinine syrinx with its normal complement of four pairs 

 of muscles. Of these the short anterior muscle ruus to the anterior end 

 of the third bronchial semiring alone in 0. spinicaiida ; whilst in 

 0. oclirocepliala this ring receives its muscular supply from a fasciculus 

 of the long anterior muscle. They thus differ essentially from Menura, 



* Garrod, Coll. Papers, pp. 203 and 293. 

 t For Part IV. see above p. 217. 



t Proc. Zool. Soc. 1882, pp. 544-546. Read June 6, 1882. 

 In 1848. Vide ' Vocal Organs of Passeres,' Garrod's edition, p. 36. 

 I 'Tentaraen,' pp. 9 & 11. 



