PHYLOGENY OF THE PALHZOGNATHZ AND NEOGNATH-E. 171 
B. NESstLines. 
The neossoptiles consist of prepenne only. 
In Dromeus, Casuarius, and Apteryx the prepenna has a well-marked rhachis and numerous 
rami. The aftershaft is feeble or wanting. 
In Dromeus the rhachis bears about 8 pairs of rami: the rami are produced into 
points beyond the distal radii. 
In Casuarius the rhachis does not bear more than 5 pairs of radii. 
In Apteryx the rami exceed 8 pairs; the rami are not produced beyond the radii ; 
the prepennze of some parts recall the adult down of Ducks. 
In Rhea and Struthio the prepenna is umbelliform ; the main shaft is represented by 3 rami, 
the aftershaft by numerous rami. 
In Rhea the rami of the main shaft are not greatly elongated or flattened. 
In Struthio the distal ends of the rami of the main shaft are much elongated and 
peculiarly flattened and grooved, as in Tinamide. 
In Crypturi the prepenna is very complex ; the aftershaft equals the main shaft in length. 
OSTEOLOGY. 
THe SKULL oF THE ADULT. 
The skull of the Palewognathe—which, as we have elsewhere shown, includes the 
so-called Ratite and Tinamous—differs from all other known birds in that, in the adult, 
the pterygo-palatine connection is by symphysis or anchylosis, and not by an arthrosis. 
The skull of the Tinamous, as will be shown presently, closely resembles that of 
Rhea. 
The Occipital Region (Pl. XLII. fig. 7).—The occipital condyle is sessile, and the 
plane of the occipital foramen is inclined backwards, in all the Palwognathe save 
Dinornis, Zpyornis, and Apteryx, and in the Tinamous. In Dinornis the plane of the 
occipital foramen is nearly vertical; in Apteryx the occipital condyle is pedunculated. 
In Dinornis and AXpyornis this condyle projects beyond the dorsal margin of the 
foramen. In Dromeus and Apteryax the supra-occipital, immediately above the foramen 
magnum, presents the concavo-convex “cerebellar dome” so characteristic of the 
Tubinares and Sphenisci. ‘There is a well-marked supra-foraminal ridge (Pl. XLII. 
fig. 8) running laterad on either side to become lost on the paroccipital process in all 
save Apteryx and the Tinamous. In Apteryx the ridge ends abruptly in the form of 
two pendent tubercles on either side of the foramen at about halfway down. In the 
Tinamous the ridge terminates in the same region, but is without tubercles. The 
occipital crest is most strongly marked in Rhea. The lambdoidal ridge runs outwards 
and downwards as a sharply-defined ridge, terminating in a pair of strongly compressed 
paroccipital processes, in all save Dinornisand Struthio. In these the ridge has a more 
or less sinuous outline, and is not so easily followed. Only in Dinornis does the 
lambdoidal ridge delaminate, as it were, in the region above the occipital crest, to 
form anterior and posterior lambdoidal ridges, 
