Birds of America
By John James Audubon, F. R. SS. L. & E.
VOLUME I.
GENUS IX.--FALCO, Linn. FALCON.
Bill short, robust; its upper outline decurved from the base; cere short,
bare; edge of upper mandible with a festoon and a prominent angular process.
Nostrils round, with an internal ridge, ending in a central tubercle. Feet
strong; tarsi moderate, reticulate; toes long, broadly scutellate, the anterior
webbed at the base; claws long, well curved, very acute. Wings long, pointed;
second quill longest, first and third nearly equal; outer toe abruptly cut out
on the inner web. Tail rather long, nearly even.