xv, i Shufeldt: The Monkey -eating Eagle 37 
near congeners, both fossil and existing forms, and it may be 
said that we meet with few marked differences in any of them 
with respect to the characters presented on the part of the 
hyoidean arches, or skeleton of the lingual apparatus (Plate 
III, fig. 10). 
The anterior soft part of the glossohyal is long and narrow, 
being covered for its anterior two-thirds with the usual horny 
sheath. Posterior to this, the glossohyal is narrow and bifur- 
cated, articulating, as usual, with the basihyal posteriorly. 
This part is likewise thinly overlain with a horny sheath. All 
this part is very feebly developed, extremely elongate, and 
narrow. 
Triangular in outline, the basihyal supports posteriorly an 
elongate urohyal, which is of small and nearly uniform caliber; 
it is tipped off with a very small bit of cartilage behind. This 
urohyal is perpendicular to the transverse line of the base of 
the basihyal, and in the right angle upon either side of the 
former articulates the head of a hypobranchial. Each hypo- 
branchial is long and curved upward for its entire length. Both 
the anterior and the distal ends are somewhat enlarged, the 
posterior enlargements being continued in cartilage for a few 
millimeters, when, upon either side, its place is taken by a cera- 
tobranchial. Either one of these is about 1.5 centimeters long, 
slender, ,and to some extent curved in line with the upcurved 
hypobranchial of the same side. Each ceratobranchial termi- 
nates behind in a fine, needle-pointed, cartilaginous tip. 
Our white-headed eagle (Haliseetus leucocephalus ) possesses a 
hyoid very similar to this; but the angle made by the urohyal 
and the basihyal is an obtuse one instead of a right angle, as it 
is in Pithecophoga, and the cartilaginous part of the glossohyal 
is extremely short, while the broad, osseous part has the form of 
a capital letter H, with the sides converging toward each other 
from behind forward. 
Eagles, in so far as I have examined them, possess a very 
simple form of larynx and trachea. The former presents the 
usual osseous elements, but they form no special articulations 
with each other, the contour of the structure being sustained in 
their membrane, with the aforesaid elements simply maintained 
in their several positions by it, and nowhere in contact with 
each other. All the tracheal rings — and they are very numerous 
— appear to be, to some extent, performed in cartilage (Plate 
III, figs. 6, 10) . Each is of the usual ornithic type, the broader 
ones being above and below. There are upward of seventy of 
