SKELETON OF PHORORHACOS INFLATUS. 71 
only slightly grooved at its posterior end; there is no fossa into which the cuneiform 
fits when the manus is flexed upon the forearm; the so-called pisiform process is 
almost absent. The prominence formed by the fused first metacarpal is stout and 
short, and terminates in a roughened surface which may possibly have formed the base 
of a short horny spur or knob. Distally the first metacarpal terminates in a tubercle 
for articulation with the phalangeal. The second metacarpal (mec. 2) is short and 
thick, compressed laterally and slightly curved. On its upper surface there is a nearly 
longitudinal, faintly marked groove, and on the anterior surface of the distal end is 
another short groove for tendons. 
The third metacarpal (mc. 3) is much more slender than the second; it is strongly 
curved and so compressed that it forms a mere band of bone. On its ventral surface at 
the proximal end is a prominent tubercle (¢.), which will be referred to below ; distally 
it is fused with metacarpal 2 in the usual manner. The distal extremities of the fused 
metacarpals bear each an articular surface for their phalangeals, as in most birds. The 
length of the metacarpus is 76 mm. 
The reduction that has been undergone by the bones of the wing makes their 
comparison with those of other birds difficult. 
The distal portion of the humerus differs widely from the Albatross, in which the 
impression of the brachialis anticus is in a different position and there is a large 
ectepicondylar process. In the Birds of Prey the depression on the anterior face above 
the articular surfaces is always much less than in Phororhacos, and the impression 
of the brachialis anticus is more median ; in some the distal border is somewhat oblique 
and there is a trace of the distal process. 
In Ciconia the distal border is not oblique and the position of the Jrachialis impres- 
sion is quite different. 
In Grus the differences are the same as in Ciconia. 
In both Cariama and Psophia also the distal border is only slightly oblique (in 
Cariama there is a trace of a blunt distal process on the ulnar side). 
The humerus to which I find most resemblance in the form of the distal end is that 
of Diaphorapteryx, the large extinct Rail of the Chatham Islands. In this the distal 
border is oblique, there is a fairly prominent distal process, and the form and position 
of the brachialis anticus impression is similar. The humerus of Aptornis is also some- 
what like the fossil, but in it reduction has gone further, the division between the radial 
and ulnar condyles being still more indistinct and the distal process small. 
The short, stout vlna is not very much like that of any of the birds referred to in the 
comparison of the humerus, but approaches that of Psophia most nearly. 
The proximal end of the right radius is preserved. Its articular surface is oval in 
outline, and the bicipital tuberosity is strongly developed. It is almost identical with 
the same element in Cariama, but the characters of the radius are not sufficiently different 
in the various groups to be of much importance in determining affinities. 
VoL. Xv.—PART ul. No. 3.—October, 1899. M 
