218 NORTH AMERICAN BIRDS. 



Order RAPTORES. — Birds of Prey. (Page 2.) 



Families. 



a 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 ; 

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



corhamphi.) Cathartidae. (Page 218.) 



a?. 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 . Byes lateral, not surrounded by disks of radiating feathers ; cere exposed ; 



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



Falconidse. (Page 222.) 

 b 2 . Byes directed forward, surrounded by disks of radiating feathers ; cere con- 

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

 (Suborder Singes.} 

 c\ 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.) 



<?. 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. 



Bubonidee. (Page 255.) 



Family CATHARTIDiE.— The American Vultures. (Page 218.) 



Genera. 



a}. 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. 

 b l . 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.Q0, or more) Sarcorhamphus. 1 



1 Sarcorhamphui DuMfiniL, Zool. Anal. 1806, 32. Type, by elimination, Vultur gryphua Linn. 



