Appendix. 6 7 



not even Rxipicola crocea, which has been thought by some to be intimately related to the 

 Eurylaeminae. 



Such being the case, I cannot do otherwise than divide the Passeres into two main sections — 

 the Eurylaeminae, and the rest, because in all other essential respects they agree. 



Four or five pairs of muscles running to the ends of the topmost three bronchial semi-rings 

 constitute the Oscine syrinx, the distinctive features of which are therefore its Acromyodian and 

 complex nature. MM. Keyserling and Blasius were • the first to associate with this the bilaminate 

 planta — an exception to which occurs in the case of the Alaudidae, as we all know, these birds 

 possessing a divided planta together with an Oscine syrinx. In lleterocneniis naevia, as has been 

 shown by Mr. Strickland ', the planta is indistinguishable from that of the bilaminate Oscines. 

 With reference to this and closely allied genera it must be noted that the scutellation of the 

 front of the tarsus is also obliterated, so that the simplicity of the planta is only a participation 

 in the condition which oljtains ia the tarsus generally. Therefore, with this exception (which 

 from its associations can hardly be looked upon as such), it may be said as yet that no bird which 

 is not acromyodian has a bilaminate planta. 



Nevertheless the law enunciated by Cabanis, to the effect that when in a Passerine bird 

 possessing ten primary remiges the first is long, then that bird is not Oscine (or Acromyodian), 

 but ' Clamatorial ' (or Mesomyodian), led that able ornithologist to place Pitta in the latter group, 

 although it pos-esses a bilaminate planta; since which time .Johannes Miiller is not the only biologist 

 who has wished to know the nature of the syrinx of that bii-d, of which Sundevall", in 1872, 

 remarks, 'musculi laryngis inferioris ignoti.' 



In Fitta amjohnsis the unmodified trachea terminates thoracically in a ring, split behind, 

 and deep in front ; which, from the fact that it presents irregularly placed fenestrae on its 

 anterior surface, arranged in a somewhat transversely linear manner, appeal's to have been formed 

 by the fusion of two rings. This terminal segment of the trachea does not, as in the Oscines 

 and several other Passeres, form a three-way piece, because there is no antero-posterior bar traversing 

 its inferior margin in the middle line. Of this, however, there is an indication in the form of 

 a median backward-directed process, which advances a short distance into the inferior membrani- 

 form completion of the tube, from its anterior border. The tracheal ring last but one is complete, 

 and has a slight median indentation in its inferior margin behind. These points are seen in 

 Plate VIII, figs. 11-13. 



The first and second bronchial ring-segments are semi-rings — not modified into the somewhat 

 separate, round-margined, slightly oblique semicircles of fibro-cartilage or bone which, as usual, 

 are found nearer the lungs — but are like moieties of true tracheal rings, approximate, sharp-edged, 

 and at right angles to the axis of the tube. They present no peculiar processes, and are slightly 

 swollen at their anterior extremities. 



There is only a single pair of bronchial muscles, continued down from the sides of the 



' Annals and Mag. Nat. Hist. 1844, vol. xiii, p. 415. 

 ^ Method, nat. Av. disp. Tentameu, 1872, p. 5. 



