of the United States. 25 



acuminated. Female similar in colour, though larger than 

 the male. 



SUBGENUS I. AQ.UILA. 



Aquila, Briss. Meyer. Cuv. Vieill. 



Bill very robust, angular above ; cere subhispid ; nostrils 

 rounded-elliptical, transverse. Feet very robust ; tarsi feather- 

 ed to the toes ; middle toe considerably longest, connected at 

 base by a membrane with the outer ; nails large, very sharp 

 and incurved, the middle one pectinated on the inner side. 

 Wings elongated ; first primary very short ; fourth longest. 



The most powerful of the genus, surpassing all others in 

 courage and strength, carrying off even large animals. In- 

 habit mountainous districts. Sight keen. Sense of smelling 

 imperfect. 



6. Falco fulvus, L. Dusky; cere and toes yellow; tail 

 rounded, reaching beyond the wings ; three scales only on 

 the last joint of each toe. 



Adult : tail fasciated with blackish. 



Young : tail white at base, blackish towards the tip. 



Ring-tailed Eagle, Falco fulvus, fVils. Am. Orn. vii. jp. 

 13. pi. bb.jig. l, young. 



Inhabits the north, or on the highest mountains of both con- 

 tinents : rare in America. 



SUBGENUS II. HALIAETOS. 



Halia'etos, Savigny. Cuv. Vieill. 



Bill very robust, convex above ; cere subhispid ; nostrils 

 lunulated, transverse. Tarsi half feathered, scutellate ; toes 

 divided to the base ; outer subversatile ; nails subequal, be- 

 neath canaliculated ; the middle one with a deep channel, 

 and the inner side pectinated. Wings elongated ; first pri- 

 mary very short ; fourth longest. 



Chiefly piscivorous ; keep generally near the sea-shores^ 

 lakes and rivers : their great size and strength enable them 

 to vanquish large animals, birds, and mammalia: participa- 



