Carriker : List of the Birds of Costa Rica. 445 



g. Tail black, with plumbeous above ; one white bar 

 (wing 200). 



Leucoptemis sewiphtmbea, $ and 9 • 

 gg. Slaty-black above, tail grayish, with four bars of 

 blackish-brown. 



(White phase) Buteo brachyurus, ad. $ and 9- 

 ff. Upper parts mainly black. 



g. Crown, nape, and sides of head plumbeous, pure 

 white below ; tail barred with black and white bars 

 of equal width. 



Leptodon cayennensis, ad. $ and 9 • 

 g. Crown and nape black ; chest with black shaft-streaks. 

 h. Tail with only three narrow white bars; no 

 white on nape. 



Micrastur mirandollei, ad. g and 9 • 

 hh. Tail with four white bars and a white collar on 

 nape. 



Micrastur brachypterus, ad. $ and 9- 

 bb. Under parts uniform buffy-ochraceous or cinnamon-buff, or else pale ashy- 

 bluish, with chestnut thighs. 

 c. Pale bluish-ash below, thighs chestnut ; crown black ; back and wings 

 plumbeous ; tail black, with three white bars. 



Accipiter bicolor schistocklamys, adult $ and 9 • 

 cc. Buff-ochraceous or cinnamon-buff below. 

 d. No white on rump. 



e. Pileum and nape buff-ochraceous, with black shaft-streaks ; 

 sides of head with a black patch. 



Herpetotheres cachinnans, $ and 9 • 

 ee. Pileum sooty black like back. 



f. Whole inner side of quills alternately barred with grayish- 

 white and sooty; thighs deep buff-ochraceous or cinna- 

 mon-buff. 



Accipiter bicolor schistochlamys, $ and 9 » juv. 

 ff. Only basal portion of quills white, with about four narrow 

 sooty bars ; thighs same color as breast. 

 g. A white or buff-white nuchal collar ; tail with four 

 narrow white bands (dorsal aspect). 



Micrastur brachypterus, $ and 9 > j uv « 

 gg. No white or buff nuchal collar; only three white bars 

 on tail. Micrastur mirandollei, $ and 9 > j uv - 



dd. Rump white ; rich cinnamon-buff below, with darker rufous shaft- 

 streaks. Circus hudsonius, $ and $ , juv. 

 aa. Under parts variously colored, but never uniform ; always barred, streaked, or 

 with strongly contrasting areas of color. 

 b. Tail two-thirds or more than two-thirds the length of wing. 

 c . Tarsi feathered to base of toes ; an occipital crest. 



