222 NORTH AMERICAN BIRDS. 



different from the adult (?). Lenirth 2:].nO-27.00 ; extent about 54.00; wing 16.50- 

 17.50, tail 7.50-8.50, culmen .90-.95, tarsus 3.00, middle toe 2.90. JVest a bollow in 

 stump, log, or tree-trunk, or secluiled spot among undergrowth of woods. Eggs 

 1-2, 3.01 X 2.05, ovate or broadly elliptical-ovate, similar in coloration to those of 

 Cathartes aura, but usuallj' more sparsely marked. Hah. AVholo of tropical and 

 warm-temperate America, south to Argentine Republic and Chili, north regularlj- 

 to Xorth Carolina and lower Mississippi Valley, irregularly or casuallj" to Jlaiiic, 

 New York, Ohio, Indiana, Illinois, Dakota, etc. (Apparently wanting in western 

 Mexico and California) 326. C. atrata (Bartr.). Black Vulture 



Family FALCONID.^. — Vultures, Falcons, Hawks, Eagles, etc. 



(Page 218.) 



Genera. 



a'. Outer toe not reversible ; claws graduated in size from the largest (that of hind- 

 toe) to the smallest (that of outer toe), broader and (except in Elanus) 

 grooved on under side. 

 6'. Nostril not circular, nor linear and oblique, with the upper end (he posterior 

 one, nor with central bony tubercle. (Subfamily Arripitrina:) 



c\ Tail deeply forked Elanoides. (Page 224.) 



c'. Tail not deeply forked. 



d\ AVing not more than 18.00. 

 e\ Tarsi naked in front. 



/'. Front of tarsi covered with minute roundish scales; claws 



not grooved beneath Elanus. (Page 224.) 



/'. Front of tarsus covered with large transverse scutellfe; 

 claws grooved beneath. 

 g^. Cutting-edge of upper mandible notched. 



Ictinia, (Page 225.) 

 g''. Cutting-edge of upper mandible not notched. 



A'. Tip of upper mandible produced into a conspicu- 

 ous lengthened hook. 



Rostrhamus. (Page 225.) 

 li'. Tip of upper mandible not produced into a con- 

 spicuous lengthened hook. 

 P. Face encircled In- a "ruff" of short, stiffened, 

 compact feathers, as in the Owls. 



Circus. (Page 220.) 

 i'. Face not encircled by a ruff. 



f. Tail decided!}- more than two-tliirds as 

 long as wing. 

 k\ Depth of bill at base not decidedly 

 less than chord of culmen; mid- 

 dle toe equal to or longer than 



