95 
of the United States . 
the seveuth. Tail cuneiform, composed of twelve feathers, 
elastic, rigid and acuminate. 
Female and young hardly differing from the male. Moult 
annually. 
Solitary, or in families or small flocks ; frequenting woods 
and orchards. Climb upwards and downwards on the trees, 
the rigid tail serving as a support. Feed exclusively on in- 
sects, their larvae and eggs, which they seek for in the crevices 
and mosses of the bark. Lay twice a year in hollow trees; 
eggs from three to nine. 
Species few, but widely disseminated. Closely allied to 
the following family, species of which formed part of it 
as constituted by Linne, &c. Intimately allied to the Canori 
by some North American species of the genus Troglodytes. 
151. Certhia familiaris, L. Dark-cinereous, varied with 
whitish, brown and fuscous; beneath white ; rump and tail 
rusty-brown. 
Brown Creeper , Certhia familiaris , Wils. Jim. Orn. «. 
p. 122 .pi. 8. fig. 1. 
Inhabits the north of both continents ; more common in 
Europe and in the western and northern states, than in Penn- 
sylvania, which it visits only in the autumn and winter. 
28. SITTA. 
Sitta , L.Briss. Gm. Lath. 111. Cuv. Temm . Ranz. 
Sitta , JYeops , Uieill. 
Bill moderate, very hard, conic-subulate, subrounded, a 
little compressed, straight, cuneate at tip ; edges sharp ; 
mandibles equal, lower generally recurved from the middle : 
nostrils basal, orbicular, open, half closed by a membrane, 
usually covered by setaceous incumbent feathers : tongue 
short, cartilaginous, depressed and wide at base, emarginate- 
lacerated and horny at tip. Feet robust; hind toe stout, 
elongated, with a very robust, aduncate, acute nail. Wings 
