218 NORTH AMERICAN BIRDS. 



ORDER RAPTORES. BIRDS OF PREY. (Page 2.) 



Families. 



i 1 . Head entirely naked, or else only partially covered with down (in young) ; nos- 

 trils longitudinal ; a distinct web between inner and middle toes, at base ; 

 bind-toe short, elevated, the feet wholly unfit for grasping. (Suborder Sar- 

 corhamphi.') Cathartidae. (Page 218.) 



z 2 . Head entirely feathered or only partially naked ; nostrils vertical or roundish ; 

 no web between inner and middle toes; hind-toe well developed, with large, 

 sharp claw, inserted at the same level with anterior toes, the feet specially 

 adapted for grasping. 



6 1 . Eyes lateral, not surrounded by disks of radiating feathers ; cere exposed ; 



outer toe not reversible (except in Pandiori). (Suborder Falcones.') 



Falconidae. (Page 222.) 



6 2 . Eyes directed forward, surrounded by disks of radiating feathers ; cere con- 



cealed by loral and frontal bristle-like feathers; outer toe reversible. 

 (Suborder Striges.') 



c 1 . Inner toe as long as middle toe ; inner edge of middle claw pectinated ; 

 feathers on hinder part of tarsus recurved, or pointed upward ; first 

 quill longer than third, none of the quills with inner webs sinuated 



or emarginated Strigidae. (Page 255.) 



c 2 . Inner toe decidedly shorter than middle toe ; inner edge of middle claw 

 not pectinated; feathers on hinder part of tarsus (if present) pointed 

 downward ; first quill shorter than third, and at least one (one to 

 six) quill with inner web sinuated or emarginated. 



Bubonidae. (Page 255.) 



FAMILY CATHARTID^. THE AMERICAN VULTURES. (Page 218.) 



Genera. 



a 1 . Cere decidedly shorter than the upper mandible; bill very strong,' with all its 

 outlines decidedly convex. Adult males with a fleshy " comb" or lobe sur- 

 mounting the top of the cere. 



6 1 . Plumage of adult commencing on the neck with a very distinct collar of 

 white cottony down; primaries decidedly longer than secondaries; 

 throat with a median " dewlap" ; " comb" of adult male extending from 

 near anterior border of cere to middle of the crown; sexes very different, 

 the female lacking entirely the "comb" or other fleshy appendages to 

 the head; very large (wing 30.00, or more) Sarcorhamphus. 1 



i Sarcorhamphus DUMERIL, Zool. Anal. 1806, 32. Type, by elimination, Vultur gryphut LINN. 



