Family II. FALCONINAE. FALCONINE BIRDS.
Bill short, stout, cerate; upper mandible with the tip elongated and decurved; lower mandible rounded and thin-edged at the end. Head rather large, broadly ovate, feathered. Eyes large, with prominent superciliary ridges. External aperture of ears of moderate size, and simple. Tarsus longer than the middle toe; claws very large, much curved, extremely acute. Plumage full and generally compact. Wings very long and broad: OEsophagus excessively wide and dilated into a crop; stomach large, somewhat membranous, its muscular fasciculi being placed in a single series; intestine short and rather wide, or very long and slender; coeca extremely small. The young, when fledged, generally having the lower parts longitudinally streaked. Eggs from two to six, ovate, or roundish. Nest on trees, rocks, or the ground.