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 diiferences 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 



