PHYLOGENY OF THE PALZOGNATHA AND NEOGNATELE, 235 
ulnare, and distal carpal mass, but also an intermedium, an element which has so far 
been recorded previously in Opisthocomus and Dendrecia. 
The fact that in the adult Apterya there is a distinct alar membrane, or patagium, 
as has been pointed out by Parker, is strong evidence in favour of the view that the 
wing of Apteryx is a degenerate structure, once capable of performing the duties of an 
organ of flight. 
In Apyornis, apparently the wing was represented only by the humerus. A humerus, 
believed to be that of an Apyornis, has been described by Andrews. Its length was 
63 mm. ‘The upper end resembled that of the humerus of Aptornis, the lower that of 
Casuarius, “but still further reduced, the radial and ulnar trochlee uniting completely 
to form a single articular surface.” 
Toe Pewvic Live, 
The differences between the pelvic limbs of the existing Palwognathe are neither 
many nor great. 
In Dromeus the femur differs from all the other Palwognathe, save Struthio, in 
that it is highly pneumatic, and bears on the ventral aspect of the femur a large 
pneumatic foramen. It lies between the great trochanter and the head of the femur. 
The popliteal fossa is of moderate depth. 
The tibio-tarsus is not easily distinguishable from that of Caswarius. The chief 
difference appears to rest in the slighter and less vertically extended procnemial crest. 
This vertical direction is rather marked in Caswarius. The fibula extends to the lower 
fourth of the shaft of the tibio-tarsus. 
The tarso-metatarsus is as long as the tibio-tarsus, grooved in front, and has a 
moderately developed median keel to the hypotarsus. 
The proximal phalanx of digit 1. is relatively long, the 2nd very short; in digit Iv. 
the proximal phalanx is long, the 2nd and especially the 3rd and 4th are very short. 
The pelvic limb of D. ater closely resembles that of D. novw-hollandiw. ‘The 
anterior metatarsal groove is, however, somewhat deeper. 
The outer toe, in each foot, in this skeleton has lost one phalanx. 
In Caswarius the femur is non-pneumatic. ‘Lhe position of the pneumatic fossa in 
Dromeus may be indicated by a minute aperture. The tibio-tarsus, as already pointed 
out, differs but slightly from that of Dromeus. 
The tarso-metatarsus is much shorter than the tibio-tarsus, is very deeply grooved 
anteriorly, and is pierced by a foramen dorsad of the scar for the tibialis anticus. 
Thus it can readily be distinguished from the tarso-metatarsus of Dromeus. 
The ungual phalanx of the inner toe is greatly elongated; in other respects the size 
of the phalanges closely agrees with those of Dromeus, but the proximal phalanx of 
digit m1. is relatively shorter. 
