72 MR. C. W. ANDREWS ON THE SKULL AND 
The metacarpus differs widely from that of Diomedea, Grus, and Ciconia, and is most 
like that of Psophia and Cariama. 
In both these birds, as in Phororhacos, there is on the ventral edge of the third 
metacarpal, close to its base, a small process forming a projection (t., fig. 6, Plate XVIL.) 
on the palmar aspect of the manus. I have not observed this in any but these birds, 
and of them it is most strongly developed in Cariama, in which, however, there is a 
prominent pisiform process. 
On the whole, the evidence of the wing-bones seems to point to relationship to the 
aberrant Gruiform birds Cariama and Psophia: but in the humerus there is resemblance 
to such Rails as Ocydromus, Diaphorapteryx, and Aptornis, in which also the wings 
have undergone more or less reduction; in this case the similarity may merely be due 
to convergence in degeneration. 
Sacrum and Pelvic Girdle. . (Plate XVI.) 
The vertebre uniting to form the so-called sacrum (fig. 5) (synsacrum, Parker) are 
about fifteen in number. The most anterior articulated with the last free dorsal by the 
broad saddle-shaped surface of the centrum and by very large anterior zygapophyses. 
The neural spine of this vertebra is high and its summit is overlapped by and fused 
with ossified fascize which form a forward extension of the supero-anterior angles of the 
ilia; looked at from the side a great part of the spine is exposed to view, the anterior 
borders of the ilia only just overlapping its hinder edge; between the spine and the 
ilia there is on either side a chink-like ilio-neural canal. 
Tubercular and capitular facets for a free rib are present, and both are roughly 
semicircular, the convexity being directed upward and forward. ‘The capitular facet, 
borne on a slight parapophysial elevation, is close to the anterior end of the centrum 
and at the lower end of a ridge which runs upward and backward, bearing near its 
upper end the tubercular facet. From this a bar of bone, apparently equivalent to the 
zygapophysial bar of a free vertebra, runs back and unites with the antero-inferior 
margin of the ilium; from the tubercular facet a metapophysial ridge runs forward on 
to the zygapophysis. Just behind and above the capitular facet there is a pneumatic 
fossa of moderate size. The ventral surface of the centrum is pinched up so as to form 
a sharp median ridge. 
In the second vertebra the neural spine is completely concealed by the ilia, and 
running upward and backward from the anterior end by the centrum there is a thick 
ridge which, near its lower end, bearsa facet for the capitulum of a rib, and at its upper 
end abuts against the lower border of the ilium; here also there is a median ventral 
ridge. These vertebre are probably thoracic. 
The centra of the next few vertebre have been destroyed, but opposite the acetabulum 
they are again preserved. In this region the median ventral ridge is replaced by 
a median groove defined by slight ridges, and disappearing opposite on the second of 
the true sacrals As far as opposite the middle of the acetabulum the vertebre may be 
