of the United States . So 
acuminated. Female similar in colour, though larger than 
the male. 
SUBGENUS 1. AQXJILA, 
Aquila , JBriss. 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 , Wils . Am. Orn . vii. 
13 •pi. 55 .fig. l. young. 
Inhabits the north, or on the highest mountains of both con- 
tinents : rare in America. 
SUBGENUS II. HAUAETOS. 
Halia'etos 9 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- 
