OSTEOLOGY OF BIRDS 89 



Outlines of the skulls of certain Accipitres; life size from photographs by the author 

 Fig. 41 Left lateral aspect of the skull of F a 1 c o m e x i c a n u s 



Fig. 42 Basal view of the skull of Buteo borealis calurus: mandible 

 removed 



Fig. 43 The same of E 1 a n u s 1 e u c u r u s 



Fig. 44 Left lateral view of skull and mandible of Polyborus lutosus 



