206 MR. W. P. PYCRAFT ON THE MORPHOLOGY AND 
The supra-angular, in all, articulates proximally with the articular. Its dorsal 
border is received between the right and left moieties of the superior limb of the 
dentary. Its ventral border descends caudad to the level of the inferior border 
of the angular; distad it rises gradually so as eventually to cross the dorsal border of 
the same. 
The coronary is in all a short, slender, and rod-like bone. In many Neognathe it 
is often of considerable size and laterally compressed. 
In all the Paleognathe it appears to extend backwards so as to embrace the 
inner border of the articular and to form the internal boundary of the articular surface 
for the quadrate. In Rhea and Apterysx it is very feebly developed distad, and may be 
described as vestigial. In Caswarius and Dromeus it is much larger. Struthio is 
intermediate. In no case does it extend forwards beyond the posterior third of the 
ramus. 
Such characters of the skull as are of use for systematic purposes will be found in 
the “Keys” at the end of this paper. 
More material is needed before these can be made complete, since a “ Key” to the 
species has not been possible in the case of Caswarius. Whether the characters 
considered to be specific in the case of the other genera will stand the test of time 
remains to be seen. In several instances I have been obliged to rely upon the characters 
of a single skull, as in the cases of the skulls of Rhea macrorhyncha, for instance. 
I feel justified in reviving Dr. Sclater’s Struthio meridionalis [go| on account of the 
many marked peculiarities which the skull and the trunk of this skeleton presents. 
The work of distinguishing the skulls of the four species of Apteryx has been a very 
difficult one. Indeed, as Mr. Beddard has already remarked [8], “the very slightest 
differences, apart from those of size, distinguish the Apteryges.” 
Some Points or SIGNIFICANCE IN THE STRUTHIOUS PALATE. 
The following points appear to be worthy of special consideration and may fitly be 
discussed here. 
In comparison with the palatines of the Neognathe, it will be remarked that in 
Rhea, as in the other Palwognathe, the palatines are widely separated one from 
another by the laterally expanded feet of the vomer. In the Neognathe the palatines 
meet in the middle line, thrusting the vomer forwards, so that it now appears to 
articulate not with the pterygoid but with the palatines. In Rhea and Crypturi we 
have probably a clue to the way in which this has come about. ‘Turning once again 
to the skull of Dromeus, we notice that the palatines are only loosely attached to the 
outer border of the vomerine feet, whilst in Rhea (Pl. XLII. fig. 5) the palatines have 
moyed inwards so as to overlap these feet and approach one another mesially. Their 
