248 MR. W. P. PYCRAFT ON THE MORPHOLOGY AND 
of the vomer. It can be readily prepared in a well-macerated skull by carefully 
removing the vomer. It was first described by W. K. Parker [77] in Rhea. 
THE ALIMENTARY CANAL. 
Buccau Cavity, 
The buccal cavity of the Palwognathe presents one noticeable feature wherein it 
differs from that of the Meognathew (Pl. XLV. fig. 1): since, in the former, the 
posterior nares, or choanz, form a wide, open, more or less cordiform aperture, divided 
by a median septum into right and left lateral moities; in the Neognathe the 
choane are slit-like. The Eustachian aperture lies immediately caudad of the choane. 
In all the Palwognathw the tongue is more or less vestigial. The glottis is also 
a relatively wider aperture than in the Neognathe. In Casuarius the tongue has a 
denticulate free edge. 
THE CONVOLUTIONS OF THE INTESTINE. 
Dr. Gadow, in his paper “ On the Intestinal Convolutions in Birds” [26], considered 
the flightless members of the Palwognathe a very heterogeneous group, because of 
the great diversity in the length and arrangement of the main gut and in the develop- 
ment of the ceca. “In none of these birds has it come to the development of closed 
and well-developed loops of the mid-gut (with the exception of the duodenum). In 
this respect they represent the lowest type amongst the recent birds... .. Their 
connections with recent Carinatz are distant. Nearest of them to the latter comes 
Apteryx through more defined loops, and the Crypturi seem to represent the link... . 
All the Archwopalatine agree with each other in having the second loop right-handed 
and the third left-handed; this is a feature which occurs again only in the Crypturi, 
Galline, Opisthocomus, and in the Cuculide.” 
Amongst the Weognathe, it will be remembered, Gadow was enabled to demonstrate 
a greater harmony, the convolutions of the intestines being always referable to one of 
seven types. 
Dr. Gadow’s conclusions, it should be remarked, are based upon a study of the 
coiling of the intestines within the body-cavity. 
Mr. Mitchell [60], who approached the study of the intestinal tract from a different 
point of view, viz., after its removal from the body, and the severance of certain 
vessels and secondary connections, which reveal the nature of the convolutions of the 
gut along its attachment to the ventral border of the dorsal mesentery, and the 
position of the diverticulum cecum vitelli and its relation to the middle mesenteric 
vein, entirely confirms Dr. Gadow’s conclusions as to the primitive nature of the 
Palwognathe judged by this standard. He remarks:—‘‘It is plain that, so far as 
