280 ON THE TRACHEA OF CERTAIN DUCKS. 
osseous, irregularly compressed, and very small, not having a di- 
ameter in any part greater than that of the trachea itself (vide figs. 1 
and 2). _ 
Fig. 2. Fig. 3. 
a 
oe. 
> 
et 
beonlll 
Femmes 
= 
al 
ar 
Pi: 
Dl 
Dagegt 
= 
(gent 
sd 
‘T) 
a 
re 
TELS i 
ee. 
Mipediddtidisite 
mene = 
Fig. 1. Lower part of trachea of Sarcidiornis melanonota @ . 
Fig. 2. Ditto of Sarcidiornis melanonota ¢ . 
Fig. 3. Ditto of Rhodonessa caryophyllacea $. 
In the male specimen the ceca are 3 and 2} inches long; in the 
female not quite 2 inches. Their diameter is inconsiderable, not 
exceeding 1 of an inch. The whole intestinal canal measures between 
44 and 5 feet; and the gizzard is decidedly small, not being bigger 
than that of a common Duck (Anas boscas). 
2. RHODONESSA CARYOPHYLLACEA (Lath.). 
Anas caryophyllacea, Scl. ‘‘ Proceedings of the Zoological Society,” 
1874, p. 110. 
This rare Duck is generally placed in the genus Anas; by Mr. 
Eyton, however, it is considered to belong to the Fuliguline ; and that 
ornithologist puts it, along with Fuligula rufina, in the genus Callichen. 
A pair purchased by the Society on the 12th January last year, 
died, the female on the 11th and the male on the 15th of March, 1874. 
From these two specimens I was able to remove the windpipes for 
examination. The structure of the syrinx of the male is in favour of 
