NOTES ON THE STRUCTURE OF BIRDS. 
MENUKA. 
In a former number wo figured a part of the intestinal canal of 
Penelope cristata , that it might be compared with a plate to be 
given afterwards of that of the Australian Menura. 
On one of the plates of the present number, we have represented 
the cloaca and csecal appendages of both birds ; and on the other, 
a portion of the intestinal canal of Menura. In the first, the 
difference in the structure of the cseca of Penelope, referred to at 
p. 27-3 of “ Contributions ” for 1848, is very marked. In Penelope 
they are very long and narrow in diameter, as in most rasorial 
birds ; in Menura , on the contrary, they are extremely short, almost 
abortive. 
On our other plate devoted to the structure of Menura, we see 
the oesophagus wide and capacious, narrowing at about half its 
length, and again dilating to form the proventri cuius («) which is, 
a simple lengthened oval dilatation of about i . 2 or 3 in diameter. 
When inflated, it constricts before entering the very small but 
muscular gizzard (6). The pylorus externally seems to leave the 
gizzard near to the entrance of the proventriculus, and soon dilates 
into a duodenum (c) of moderate size. The gizzard, when laid open, 
showed considerable strength ; the two muscles, when transversely 
cut, being nearly 4 across . The epithelium is strong ; the opposing 
surfaces deeply furrowed, and apparently possessing great power. 
The proventriculus, which appears externally more than usually 
48-1 
