Family 36. FALCONS, HAWKS, EAGLES, ETC. Falconidæ.
Nostrils opening in a cere at the base of the bill; hook of bill and claws well developed; plumage firm and close; tarsus usually largely bare.
Family 37. BARN OWLS. Strigidæ.
Eyes black, set in a somewhat triangular facial disc; bill more or less concealed by feathers; nostril opening at the edge of a fleshy cere; inner edge of middle toe-nail serrate; no 'ears'; tarsus feathered.
Family 38. HORNED OWLS, ETC. Bubonidæ.