xv, i Shufeldt: The Monkey -eating Eagle 41 
the hinder part of the pubic style was very different in the two 
birds ; but this is by no means the case, for in the harpy those 
elements are held in their normal position, as in life, by a lig- 
ament stretching between their distal ends; while in Pithe- 
cophaga, when this ligament has been cut, it allows the pubic 
styles to spring away from each other and hang down as shown 
on Plate IV. Moreover, the point of view from which I pho- 
tographed those two trunk skeletons was not quite the same, 
and this causes the reproduction of the rest of the bone to pre- 
sent slight differences, which do not really exist. 
Viewed from above, it is to be noted that the ilia project 
considerably beyond the sacral crest; and on the upper surface 
of their anterior border there is a raised emargination which 
is produced backward and finally runs out as a bounding line 
to the postacetabular area of the superior surface of the sacrum 
upon either side. As the ilia pass the “sacral crest,” their 
margins thoroughly coossify with it and in the same plane an- 
teriorly — that is, up to the point where these bones begin to 
diverge and are raised above the general surface on this dorsal 
aspect of the bone. At the angle where this divergence com- 
mences, the sacrum and the ilia are completely fused, and every 
semblance of posterior openings of the “ilioneural canals” is 
completely obliterated. So, too, with the rather abruptly down- 
ward-sloping “postacetabular area;” here, likewise, every sem- 
blance of sutural traces — the intersacroiliac ones — has been 
absorbed; while the intervertebral foramina, so conspicuous in 
this area in the pelves of some birds, are reduced to mere little 
pits in the general surface of the bone (Plate VI). 
Seen upon lateral aspect (Plate IV), the anterior two-thirds 
of bone — or all that part anterior to and above the acetabulum 
and antitrochanter — is supplied by the ilium of that side. Its 
surface is generally concaved and faces upward and outward. 
Anteriorly, its outer border is emarginated, and below this may 
be seen the forepart of the pelvic sacrum, the continuation of 
which, posteriorly, may also be observed through the large, cir- 
cular acetabulum and immense ischiadic foramen; the former 
is entirely lacking in any osseous base, while the latter occupies 
fully one-half of the lateral area posterior to the rather large, 
subtriangular antitrochanter and elliptical obturator foramen. 
Posterior to this great ischiadic foramen, the lateral surface of 
the ischium is triangular in outline, concave above, convex below, 
and smooth throughout. The rounded posterior ischiac border 
is nearly straight and presents no semblance of any indent that 
might suggest the presence of an “ilioischiadic.” 
