ON THE ANATOMY OF AN AUSTRALIAN DUCK. 



355 



of these that have been as yet examined exhibiting, in the male sex, 

 either one or other of (or, more rarely, both) these peculiarities. The 

 condition of the male Biziura is nearly identical with that found in the 

 females of other Ducks. Very probably it may be that characteristic of 

 all the Erismaturinae, of which, however, only Erismatura rubida has, so 

 far as I know, been examined as regards this point. In that species 



Fig. 2. 



P. Z. S. 1882, 

 p. 456. 



Mouth of Biziura lobata. 



the syrinx, judging from Macgillivray's description *, is quite similar to 

 that of Biziura, there being no tympanum whatever, but simply a long 

 box formed of several rings united. 



The examination of these two specimens has revealed a feature in 

 them very unexpected in Ducks, and only comparable with that found in 



* Audubon, Orn. Biography, iv. p. 331. 



2*2 



