8 NEW YORK STATE MUSEUM 



Fiirbringer entertains practically the same opinion when he makes 

 his suborder, the Ciconiiformes, of the order Pelarg'ornithes contain, 

 among others, the " Gens " Accipitres, which last is divided into the 

 four families Gypogeranidae, Cathartidae, and the Gypo-Falconidae. 

 This arrangement also, is probably very near the true statement of 

 the several affinities of these groups of birds. How interesting it 

 would be, were it possible to trace back through the geological record 

 the several tribes of birds now represented by the Accipitres, the 

 parrots, owls, and Caprimulgi. 



In the classification adopted in the present work, the suborder 

 Accipitres, here to be considered, will be primarily divided into two 

 superf amilies, viz : the Cathartoidea, and the Falconoidea — the first 

 to contain all the New World vultures under the family Cathartidae, 

 the latter all the Old World vutures (Vulturidae), and the entire 

 assemblage of " diurnal Raptores." These last may be divided into 

 two families, viz : the Falconidae, and the Pandionidae. 



The Falconidae will be made to contain all the falcons, kites, 

 eagles, hawks, Old World vultures and Secretary-bird, while the last 

 named family will contain Pandion alone. 



In the course of the present treatise some few references will be 

 made to the osteology of the Condor, while for the osteology of our 

 own vultures, Gymnogyps calif ornian us, Cathar- 

 tes a. septentrionalis and C a t h a r i s t a u r u b u 

 I will introduce, as I have already said in the preface, a revision 

 of my former work upon the Osteology of the Cathartidae, pub- 

 lished several years ago in the 12th Annual Report of Hay den's 

 Survey. 



Our United States Falconidae, consist then, first, of four genera 

 of kites, each represented by but a single species. (I regret to say 

 that I have at present no skeleton of Rostrhamus.) 



Elanoides forficatus Ictinia mississippiensis 



Elanus leucurus Rostrhamus sociabilis 



For the loan of 63 skeletons illustrating the osteology of the 

 Accipitres, I am indebted to the United States National Museum, to 

 its distinguished secretary the late Prof. G. Brown Goode, and to 

 Mr Lucas. .For excellent skeletons of Elanoides and Ictinia as well 

 as other Falconidae, I am greatly indebted to Mr J. A. Singley of 

 Giddings, Tex. 



