150 REVIEW OF AMERICAN BIRDS. [PART I. 
of the two species, being fully represented in specimens of 7. bewickii, 
and I think it will be necessary to make pefenicus a synonym of albi- 
nucha, and to call the species Thryothorus albinucha. 'The ap- 
proximation, too, of the localities, is an additional argument in favor 
of this conclusion. 
Total length, 5.10; wing, 2.20; tail, 2.15; exposed portion of lst primary, 
.90, of 2d, 1.40, of longest (measured from exposed base of 1st primary), 1.69; 
length of bill from forehead, .82, from nostril, .54; along gape, .90; tarsus, 
.84; middle toe and claw, .74; claw alone, .20; hind toe and claw, .61; claw 
alone, .26. 
Famity MOTACILLID. 
Bill slender, conical, nearly as high as wide at the base, with slight notch 
at the tip; the culmen slightly concave above the anterior extremity of the 
nostrils; short bristles at gape, which, however, do not extend forward to 
nostrils. Loral feathers soft and dense, but with bristly points ; nasal groove 
filled with naked membrane, with the elongated nostrils in lower edge; the 
frontal feathers coming up to the aperture, but not directed forward nor over- 
hanging it. Wings lengthened and sharp-pointed ; the primaries nine (with- 
out spurious first), of which the first three to five, considerably longer than 
the succe, fedingorm the tip; the exterior secondaries generally much emargi- 
nated at the ends; the inner secondaries (so-called tertials) nearly equal to 
the longest primaries. The tail rather narrow, emarginate. Tarsi length- 
ened, scutellate anteriorly only, the hind claw usually very long, acute, and 
but slightly curved (except in Motacilla). Inner toe cleft almost to the very 
base, outer adherent for basal joint only. 
The combination of naked nostrils, notched bill, and nine primaries, 
with the tarsi scutellate anteriorly only, will at once distinguish the 
Anthing of this family from the Alaudidx, which they so closely 
resemble in coloration, habits, and lengthened hind claw. The 
lengthened, slightly curved hind claw, much pointed wings, emargi- 
nated secondaries—the inner onés nearly as long as the primaries— 
distinguish the family from the Sylvicolidez, with which also it has 
near relationships. 
The following synopsis will serve to define the American genera 
or subgenera of Motacillide, although it will not apply to the family 
as represented in all its old-world members :— 
