Carriker : List of the Birds of Costa Rica. 447 



f. Either upper or lower tail-coverts immaculate white or 

 buff-white ; under parts not barred, or else rump 

 white or maxilla with two pronounced teeth. 

 g. Maxilla with two teeth or else rump white. 

 h. Maxilla with two teeth. 



i. Lower parts strongly barred with chestnut- 

 rufous, whitish, and dusky-sooty ; chest 

 almost entirely chestnut ; above sooty- 

 slate, unmarked. 



Harpagus fasciatus, adult. 

 ii. Upper parts brown, feathers edged with 

 fulvous ; only abdomen barred ; chest 

 streaked with brown. 



Harpagus fasciatus, juv. 

 hh. Rump white ; upper parts ashy-blue or sooty- 

 bluish ; chest dull bluish-gray ; abdomen and 

 thighs white, sparsely and brokenly barred 

 with chestnut-rufous. 



Circus hudsonius, adult. 

 gg. Maxilla with not more than one tooth ; under tail- 

 coverts white or buff-white. 

 h. Upper parts black, with a metallic lustre, or else 

 brown, barred with black or dusky. 

 i. Upper parts and whole throat, breast, and 

 tail black; abdomen white (wing 356). 



Ibycter americanus. 

 ii. Upper parts brown, barred with black 

 (wing 200). 

 j . Centre of crown brown, surrounded by 

 slaty-blue ; secondaries largely slaty- 

 blue ; below buff-ochraceous ; sides 

 spotted with black. 

 Cerchneis sparveria phalccna, adult. 

 jj. No blue on upper parts ; lower parts 

 thickly streaked with brown. 



Cerchneis sparveria thaloena, juv. 

 hh. Upper parts sooty-brown or slaty-blue. 



i. Upper parts sooty-brown or grayish- sooty ; 

 remiges and rectrices sooty-gray, barred 

 with dusky ; lower parts buff, heavily 

 streaked^with chestnut-brown. 



Accipiter velox, juv. 



ii. Upper parts slaty-blue ; sides of neck rufous ; 



under parts white, broadly barred with 



pale rufous. Acdpiter ve/ox, adult. 



ff. Neither upper nor lower tail-coverts immaculate ; either 



barred or streaked. 



