16. Sitta (Nuthatch). Bill moderate, strong, and slightly conical; lower mandible ascending from angle to point. Tongue short, horny tip abrupt and furnished with strong bristles. Nostrils basal, rounded, in deep hollow, covered by short feathers and hairs. Wings rather long; first quill much shorter than second, fourth or fifth longest. Tail short, flexible, broad, nearly square. Legs short, stout, tarsi scutellate; toes long, strong, hind toe especially, outer toe joined at base to middle toe; claws large, much hooked.
FAMILY CERTHIIDÆ
(Creepers)
Bill either straight and subulate or slender, long, and curved; nostrils basal; tail never emarginate; fourth toe coalesced at first phalanx with middle toe. Principally insectivorous.
17. Certhia (Creeper). Bill rather long, slender, compressed, decurved, pointed; nostrils basal, lateral, elongate, partly covered by membrane. Wings moderate, rounded, first feather short, fourth and fifth longest. Tail of twelve feathers, long, stiff, pointed, slightly decurved. Feet large, tarsus slender; fore toes long, united at base as far as first joint; claws moderate, but much curved; hind toe short, but with long curved claw. Plumage soft and thick, especially above.
FAMILY TROGLODYTIDÆ
18. Tróglodytes (Wren). Bill moderate, compressed, slightly curved, not notched, pointed. Nostrils basal, oval, partly covered by membrane. Wings short, concave, rounded; first quill rather short, fourth or fifth longest. Tail generally short; its feathers soft and rounded. Tarsus rather long and strong, middle toe united at base to outer but not to inner toe; hind toe as long or longer than middle toe; claws long, stout and curved. Plumage long and soft.
FAMILY CINCLIDÆ