FALCONS, HAWKS, EAGLES, ETC. 



147 



2'. Claws, not all the same length, grooved on under side. 



3. Tarsus feathered to base of toes Aquila, p. 163. 



3'. Tarsus not feathered to base of toes .... Haliaeetus, p. 165. 



2. Wing with only one or two quills cut out on KjLvL-vOO^~i 

 inner webs. Fig. 214. 



3. Nostril circular, with conspicuous bony tubercle. 

 Falco, p. 165. 



Fig. 215. 3'. Nostrl not circular, without bony tubercle. 



4. Tail deeply forked. 



Elanoides, p. 148. 



Fig. 216. 



4'. Tail not deeply forked. 

 Fig. 217. 5. Tarsus minutely scaled in front . . Blanus, p. 148. 



5'. Tarsus coarsely scaled in front. 



Ictinia, p. 149. 

 2'. Wing with three to five quills cut out on inner 



webs. 

 3. Face with owl-like ruff of stiff feathers. Fig. 218. 



Circus, p. 150. 

 3'. Face without owl-like ruff of stiff feathers. 



4. Legs feathered to toes Archibuteo, p. 162. 



4'. Legs not feathered to toes. 



5. Nostrils oblique and linear, slanting forward to cut- 

 ting edge of bill . ... . . Polyborus, p. 171. 



5'. Nostrils not oblique or linear. 



6. Tail decidedly more than two thirds as long as 



wing. 



7. Lores nearly naked . . . Parabuteo, p. 154. 



7'. Lores densely feathered . Accipiter, p. 151. 



6'. Tail not more than two thirds as long as wing. 



7. Primaries exceeding secondaries by less than 



naked front of tarsus . Urubitinga, p. 160. 



7'. Primaries exceeding secondaries by much more 



than naked front of tarsus. 



8. Adults with under parts barred gray and 

 white ; wing less than four times as long as 



tarsus Asturina, p. 161. 



8'. Adults with under parts not barred gray and 

 white ; wing more than four times as long as 

 tarsus Buteo, p. 155. 



