354 ON THE ANATOMY OF AN AUSTRALIAN DUCK. 



.p. z. s.1882, 61. NOTE ON SOME POINTS IN THE ANATOMY OF 

 P . 455. AN AUSTRALIAN DUCK (BIZIURA LOBATA}* 



Two male specimens of Biziura lobata, the first the Society has received, 

 were purchased of a dealer in February last ; both were in very weak 

 condition when received, and, unfortunately not recovering, did not long 

 survive. The trachea of this bird being, so far as I know, unknown, I 

 take this opportunity of describing it, as well as of adding some notes 

 on other points of its structure. 



The trachea is of nearly uniform calibre throughout, with no dilatation 

 anywhere in its course; below it is perhaps a little narrowed as it 

 approaches the bronchi, but in no degree laterally compressed, as it is, 

 e. </., in such genera as Anser or Cereopsis. There is no syringeal bulla 

 formed at its thoracic end, there being merely, as will be seen from the 

 annexed drawing (fig. 1), a simple ossified box, notched in front and 



Fig. 1. 



Lower part of the trachea of Biziura lobata. 



behind, and with a narrow pessular bar below. This is formed by the 

 few last tracheal and early bronchial rings co-ossified together, though 

 not equally so on each side, or before and behind. The four or five 

 preceding tracheal rings differ from those higher up the tube in being 

 narrower and of more uniform breadth throughout, not being notched 

 and incompletely ossified in the middle line, both before and behind, as 

 these are. The bronchi are quite normal in structure, being non-dilated, 

 and with partly ossified semirings of the ordinary form. 



In the non-development of a bulla, whether osseous or partly mem- 

 branous, and in the perfectly simple character of its trachea, Biziura 

 differs from all the forms of ordinary Ducks known to me, all the genera 



* Proc. Zool. Soc. 1882, pp. 455-458. Eead May 16, 1882. 



