442 bihds of illixois. 



A. NVins less tbnn IS inchog; Inner webs of not more than (our or Ave outer quIIU dls- 

 tinrtly uiniireinutod. 

 a'. Lower half, or more, of torsi naked. 



Ii'. Front u! tarnl without transvorsf' scutellH>. 



1. Elanoide*. Tail t'xi'csslvoly forked, the lateral reptrices more than twice 

 us lunu us the middle pair. Claws grooved beneath. Tarsi covered with 

 larKO, Irreeuliir sonles. 

 -. Elanoi. Tall di>nVili>-roundt>d. Claws rounded on their under side. Tursi 

 orivi;re(l with minute roundish seales. 

 f)'. Front of tarsi with transverse scutellic. 



<'<. Tail omarfrinnto. and bill greatly hooked or else distinctly notched and 

 toothed, 

 •t. lotinia. Dill Falcon-like, with distinct, though not prominent, notch 

 mill ticth. Foi't small and robust, the claws not unusually elonguted. 

 i Bostrhamtu. Bill vrry slender and greatly hooked, entirely devoid of 

 notch or tooth. Feet slender, the claws unusually lengthened. (Ex- 

 trnllmltul; tropical.) 

 (''. Tall truncate or rounded, or if emarginatc the bill neither greatly hooked 

 nor distinctly notched. 

 (P. Form slender, the head proportionally small, the legs slender, claws 

 very acute, and tall lengthened. Bill comparatively weak, com- 

 pressed, high through the base, the culmen much ascending 

 basally, nnd the cere decidedly arched. 

 6. Cirous, Face surrounded by a "ruSr of Btitfened. differently formed, 

 feathers, as in the owls. Tarsus more than twice as long as the 

 middle toe. Wing very long, outer four primaries with inner webs 

 sinuatcd. 

 C. Aooipiter. Face without ruff. Tarsus less than twice the length of 

 till' miiUllc toe. Wing short, very concave beneath, the outer aulll 

 much bowed, the live outer with Inner webs emnrglnated. 

 (P. Form short and heavy, the head larger, tall shorter, and legs more 

 robust, with claws less acute. Bill stronger, less compressed, 

 lower through the base, the upper outline less ascending basally, 

 and ccic less arched. 

 '. Farabuteo. Form heavy, the wings and tail moderately long, and 

 feet very robust: bill rather elongated, the commissural lobe 

 prominent, and the base of the culmen somewhat depressed. 

 Fourth quill longest; outer five with Inner webs cut. Lores naked. 

 and almost destitute of bristles. lExtralimltal.) 

 8. Onyohotea. Outstretched feet reaching beyond end of tall; tiblol 

 plumcH short, close, not reaching below the joint. Wing short, 

 rounilcil. very concave beneath, the fourth quill longest; outer Ave 

 with inner webs sinuatcd. Tail short, but little more than half the 

 wing, slightly rounded. Claws very long and extremely acute. 

 (Extralimltal.) 

 0. Asttirina. Bill and feet as in Parahtiteo; lores densely bristled; 

 wing short, rounded, concave beneath, the third to fourth quills 

 longest; outer four with their inner webs cut. 

 10. Buteo. FormofPorndii/co, but primaries longer and more pointed, 

 the fourth usually longest, and the outer three or four with inner 

 webs cut. Tail moderate, or rather short, nearly even, or slightly 

 rounded, 

 o'. Tarsus densely feathered to the base of the toes. 



11. Arohibuteo. Feathering of the tarsus interrupted behind by a bare strip 

 along till' full Ivngth. Nostril broadly oval. obliquely horizontal; bill 

 weak, the upper outline of the cere much ascending basally. Feathers of 

 the nape normal, blended. Third to fourth quills longest; outer four or 

 live with Inner webs cut. 



