250 MR. W. P. PYCRAFT ON THE MORPHOLOGY AND 
Ceca of Rhea americana. 
8.7.=small intestine. 
c.=ceea. 
1.i.=large intestine, forming 7.l.=rectal loop. 
mesenteric vein. The distal limb of the duodenum presented a short lateral diver- 
ticulum, and the ceca are relatively longer than in Caswarius, and, as has been 
described frequently, were marked by the attachment of a spiral valve. But the rectal 
part of the intestine, that supplied by the posterior mesenteric vein, is expanded into 
an enormous coil swung at the circumference of a semicircular expansion of its 
mesentery. Only in Chawna, and in the Eagles and Petrels, have I found the slightest 
trace of a convergent resemblance to this feature, but in the latter the subsidiary rectal 
loops, although supplied by the rectal vessel, lie above the czeca.” 
According to Beddard the spiral valve of the ceca contains about twenty turns. 
These ceca, he points out, are furthermore remarkable in that they open into the 
rectum by a common orifice, thus differing from those of all other birds. 
The ceca of the Tinamous resemble those of Casuarius; Calodromas elegans, 
however, affords a remarkable exception, differing as it does in this matter from all 
other known birds. These ceca have been described and figured by Beddard [6]. 
They are much wider than usual, and haye the outer walls produced into numerous 
prominent diverticula decreasing in size from behind forwards. 
