1 50 REVIEW OP AMERICAN BIRDS. [PART I. 



of the two species, being fully represented in specimens of T. hevnckii, 

 and I tliink it will be necessary to make petenicus 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 1st 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. 



Family MOTACILLID^. 



Bill slender, conical, nearly as high as wide at the base, with slight notch 

 at the tip ; the oulmen 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 Motacilld). 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 

 Anthinge of this family from the Alaudidae, 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 ones nearly as long as the primaries — 

 distinguish the family from the Sylvicolidse, with which also it has 

 near relationships. 



The following synopsis will serve to define the American genera 

 or subgenera of Motacillidae, although it will not apply to the family 

 as represented in all its old-world members : — 



