Family II. FALCONINAE. FALCONINE BIRDS.
GENUS VIII. NAUCLERUS, Vig. SWALLOW-TAILED HAWK

Bill short, wide at the base, much compressed toward the end; upper mandible with the dorsal line decurved from the base, the sides slightly convex, the edges with a slight festoon, the tip narrow and acute; lower mandible with the angle very wide, the dorsal line straightish, the tip rounded and declinate. Nostrils round, with a central papilla. Head rather large, roundish, flattened; neck short; body compact. Feet short; tarsus very short, thick, scaly all round; toes scutellate above, scabrous beneath, with pointed papillae; claws rather long, curved, acuminate. Plumage blended, glossy. Wings extremely long, pointed, the third quill longest; secondaries short. Tail extremely long, very deeply forked.