OSTEOLOGY OF SIRDS 



103 



These remarks apply with less truth to specimens of Falco 

 columbarius; we rarely, if ever, find a ramal vacuity upon 

 eitlier side of the lower jaw. In all these falcons the supraoccipital 



Jl^-Sf. 



fi^.Sz. 



FiG. 51 Right lateral view of the skull of the Golden eagle (A. chrysaetos); 

 slightly tilted upward, the right side being the higher 



Fig. 52 Right lateral view of the skull of the White-headed eagle ( H . 1 e u c o - 

 cephalus); seen upon direct aspect. Both figures outlined from photographs and 

 reduced about one fourth 



prominence is conspicuous, but never pierced by a foramen in any 

 of the material examined by me. 



In the nestling Sparrow hawk (Falco s p a r v e r i u s ) we see 

 many points of interest that are in progress during the develop- 



