220 ON THE ANATOMY AND SYSTEMATIC 



primary division of the Tracheophone Passeres, which may be defined as 

 follows : 



Conopophagidce. Tracheophonine Passeres, with a holorhinal skull and 

 four-notched sternum, an exaspidean tarsus, and a syrinx with no 

 intrinsic muscles, and with the sterno-tracheales not attached to the 

 processus vocales. 



As regards the possession of a four-notched sternum by these birds 

 and the Pteroptochidse, I am not inclined to consider it in any way a 

 primitive character, but rather as an instance of a simple modification 

 having been independently acquired in different groups of birds (many 

 parallel cases might be given). The Tracheophonine syrinx must, without 

 doubt, be regarded as a modification of some Haploophonine form * ; and 

 in all these last birds, as in the still less specialized Eurylaemidae, the 

 sternum has the typical form with but two notches. On the other hand, 

 the similarity of form of the sternum in the Pteroptochidas and Conopo- 

 phagidse may very probably indicate that these groups may both have 

 sprung from some common stock which had already developed a peculiar 

 sternum. 



p.z.s. 1881, 39. NOTES ON THE ANATOMY AND SYSTEMATIC 

 p> 639 ' POSITION OF THE J AC ANAS 



IT having lately been my good fortune to dissect two specimens of 

 Parrajacana, from Pernambuco, and an eviscerated specimen of Meto- 

 pidius africanus, as well as to examine skeletons and skins of some other 

 species of this group, a few notes on their anatomy may be acceptable to 

 the Society, the more so on account of the very considerable difference 

 of opinion that has hitherto existed amongst systematic ornithologists as 

 to the true relationships of this group. Two main views on this subject 

 have been put forward, one placing the Jac,anas near the Eails (Kallidae), 

 the other asserting that they are, essentially, modified Plovers. The 

 former of these views has been maintained by Jerdon :, Sundevall , and 

 Milne-Edwards [|, to mention only some of the most recent ornithological 

 writers of importance, as well as by the illustrious Nitzsch in his classical 

 memoir on the pterylography of birds If. The latter view has been 



* Garrod, P. Z. S. 1876, p. 517. 



t Proc. Zool. Soc. 1881, pp. 639-647. Eead May 17, 1881. 

 J Birds of India, iii. p. 707. Tentamen, p. 130 (1872). 



H Oiseaux Fossiles, ii. p. 110 (1869-71). 

 If Pterylography, Bay Society's edition, p. 126. 



