248 ME. "W. P. PYCRAFT 0\ THE MORPHOLOGY AXD 



of the vomer. It can he 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. 



Buccal Cavity. 



The buccal cavity of the Palcfognatlice presents one noticeable feature wherein it 

 differs from that of the NcogimtJuv (PI. XLV. fig. 1) : since, in the former, ihe 

 posterior nares, or choanse, form a wide, open, more or less cordiform aperture, divided 

 by a median septum into right and left lateral moities ; in the Ncognatlm the 

 choanee are slit-like. The Eustachian aperture lies immediately caudad of the choanse. 



In all the Palwognatlicc the tongue is more or less vestigial. The glottis is also 

 a relatively wider aperture than in the Xeocpiathce. In Casuarms the tongue has a 

 denticulate free edge. 



The CoiNvoLUTioNS of the Intestine. 



Dr. Gadow, in his paper "On the Intestinal Convolutions in Birds" [26], considered 

 the flightless members of the Palwognathce 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 caeca. " 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 Avith recent Carinataj are distant. Nearest of them to the latter comes 

 A]jteri/x through more defined loops, and the Crypturi seem to represent the link. . . . 

 All the Archceopalatince agree with each other in having the second looj) right-handed 

 and the third left-handed ; this is a feature which occurs again only in the Crypturi, 

 Gallince, Opisthocomus, and in the Cuculidm." 



Amongst the JS^cognatha' , it Avill 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 attacnment to the ventral border of the dorsal mesentery, and the 

 position of the diverticulum cfecura vitelli and its relation to the middle mesenteric 

 vein, entirely confirms Dr. Gadow's conclusions as to the primitive nature of the 

 Palceognnthce judged by this standard. He remarks : — " It is plain that, so far as 



