xv, i Shufeldt: The Monkey-eating Eagle 33 
Passing again to the dorsal aspect of the cranium, it will be 
observed, in the craniofacial region, that a considerable depres- 
sion or concavity is present in the median area ; posterior to this 
the frontal region is broad and fiat, with the superior orbital 
margin cultrate. As in most eagles, the broad cranial vault is 
rounded and smooth, being marked only by the wonderfully fine, 
rambling, anastomosing lines that in life harbor the vessels of 
that region. I find these very well marked in the cranium of a 
white-headed eagle ( Halixetus leucocephalus ) (Plate II, fig. 1) 
where, likewise, the depression in the craniofrontal region is 
pronounced. Throughout the diurnal Raptores, this character 
varies to some degree for the species. It is fairly well marked 
in the cranium of Morphnus guianensis; and several of the cra- 
nial characters thus far described in the cranium in Pitheco- 
phaga are more or less in agreement with the corresponding 
ones in this bird (Plate II, fig. 3). This in no way takes size 
into consideration, for Morphnus is not more than half the size 
of the monkey-eating eagle while, in a way, it does refer to the 
marked craniofacial depression, the lacrymals, and the general 
form of the osseous superior mandible. No other parts whatever 
have been seen or examined by me, and even the remainder of 
this cranium is very imperfect. When the material was selected 
for me at the United States National Museum, in addition to 
those designated by myself, this imperfect cranium of Morphnus 
was included. 
In Gypaetus barbatus a lacrymal does not support a free distal 
piece as in some eagles, while the superior outstanding portion 
is to a degree elongate and to some extent twisted upon itself. 
This bird has considerably more eagle in its skull, and in the 
rest of its skeleton for that matter, than it has vulture. How- 
ever this may be, it has no special affinity with Pithecophaga, in 
so far as its skeleton would seem to indicate; and it is very 
much to be doubted that any of the rest of its morphology would 
point to any such relationship. Nothing would be gained, there- 
fore, by a comparison of the skeletal characters of these two 
birds, beyond a demonstration of the fact that they possess no 
near relationship; and this much is evident to any expert avian 
osteologist at a glance. This in no way applies, however, to such 
a form as the big eagle of Korea, Thallasoaetus pelagicus, a 
complete disarticulated skeleton of which (No. 18222, United 
States National Museum) I have before me. Paul L. Jouy col- 
lected it in that country many years ago. In its cranium it 
exhibits all the aquiline characters of an average eagle, including 
166316 3 
