PHYLOGENY OF THE PALZOGNATHA AND NEOGNATH. 223 
In the sketch the supra-coracoid foramen is not indicated, neither is there any 
indication of clavicles. 
In Casuarius the coracoid is relatively much shorter than in Dromeus. Its breadth 
equals its length. The whole sternal border rests within the coracoid groove. Unlike 
Dromeus, the pro-coracoid is large and there is a small pro-coracoid fenestra. In the 
young Casuarius the pro-coracoid is ligamentous. The supra-coracoid foramen is large 
and receives numerous pneumatic apertures. The scapula resembles that of Dromeus 
in the general form and in the size of the acromion. 
In Phea the coracoid is long and comparatively slender, tapering rapidly from its 
sternal border forwards to the supra-coracoid foramen. The pro-coracoid is ligamentous, 
leaving a conspicuous notch on the mesiaJ border of the macerated coracoid. ‘There is 
generally a supra-coracoid foramen, but this never receives pneumatic apertures. The 
whole sternal border rests in the coracoid grooves. At the base of the coracoid and on 
its dorsal surface is a large pneumatic aperture. This does not seem to be represented 
in any other Paleognathe except, and feebly, some Cryptur?. 
The scapula is peculiar, curving from the coracoid first inwards then backwards. © 
The glenoid surface for the humerus lies at the distal end of the coracoid instead of at 
its antero-lateral angle. 
In Struthio the size of the pre-coracoid is enormous, extending backwards as a long 
finger-like process ultimately to reach and fuse with the internal angle of the base of 
the coracoid, enclosing in this way a huge fenestra. The sternal (epi-coracoid) border 
of the coracoid is of great width. ‘The supra-coracoid foramen is wanting. We might 
mention here that the pre-coracoid of S. molybdophanes appears to be peculiar in its 
greater relative slenderness. 
In Apterysx the pre-coracoid seems to be wanting only in A. oweni, and in this species, 
it would seem, at all stages of its growth. In the remaining species it is represented in 
the adult by ligament only ; so that in the macerated skeleton the pre-coracoid fenestra 
is represented only by the deep notch on the mesial border of the coracoid. Ina 
skeleton of A. australis mantelli this notch has been nearly filled up by a secondary 
extension of bone in the coracoid of the left side. The supra-coracoid fenestra is 
minute or absent in all but A. oweni, in which it is large. This point, remembering 
the absence of the pro-coracoid in the latter and its presence in the remaining species, 
is interesting. 
In the Dinornithidew the coracoid has reached a state of extreme reduction, being 
yod-like and merging almost insensibly with the scapula. 
In the Apyornithide, in the form of the pro-coracoid, it is intermediate between 
Rhea and Dromeus. 
The coracoid of the Crypturi differs from that of its congeners—the flightless Palwo- 
gnathe—chiefly in that it has a well-developed acro-coracoid. There is a well-marked 
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