350 



NORTH AMERICAN BIRDS. 



32209 



Cotyle serripennis. 



Genus STELG-IDOPTERYX, Baird. 



Stelgido2yteryx, Baird, Birds N. Am. 1858, 312. (Type, Hirundo serripennis, AuD.) 



Gen. Char. Bill rather small ; nostrils oval, superior, margined behind, but scarcel}' 



laterally by membrane, but not at all overhung ; 

 the axes of the outline converging. Frontal 

 feathers soft, and, like chin, without bristles. 

 Tarsi equal to middle toe without claw ; the 

 upper end covered with feathers all round, 

 none at lower end. Basal joint of middle toe 

 adherent externally nearly to end; internally, 

 scarcely half. Lateral toes about equal, their 

 claws not reaching beyond base of middle claw. 

 Tail slightly emarginate ; the feathers broad, and obliquely rounded at end. Edge of the 

 wing rough to the touch ; the shafts of the fibrilte of outer web of outer primary pro- 

 longed and bent at right angles into a short stiif hook. Nest (of S. serripennis) in holes 

 in banks ; eggs pure white, unspotted. 

 Color dull brown above. 



The great peculiarity of this genus consists in the remarkable roughness 

 of the edge of the wing, said to occur also in PsaUdoprocne, Cab. The ob- 

 ject is uncertain, but is probably to enable the bird to secure a foothold on 

 vertical or inclined rocks, among or on which it makes its nest. A favorite 

 breeding-place of >S'. serrijmmis is in the piers and abutments of bridges, and 

 these hooks might render essential aid in entering into their holes. 



The birds of this genus have usually been referred to Cotyle, which, how- 

 ever, they resemble only in color. The nostrils are exposed, instead of being 

 overhung ; the tarsus is bare below, not feathered, and the lateral claws are 

 considerably curved, and not reaching beyond the base of the lateral, as in 

 Cotyle. The structure of the wing is very different. 



There are at least five species or races of this genus in America, although 

 only one belongs Avith certainty to the United States. A second, however, 

 {S.fulvipennis), Mexican and Guatemalan,.is not unlikely to occur in Arizona 

 or New Mexico. This differs in having the chin and throat reddish-fulvous, 

 not mouse-gray ; the belly tinged with yellow. 



Stelgidopteryx serripennis, Baird. 



ROUGH-WINGED SWALLOW. 



Hirundo serripennis, Aud. Orn. Biog. IV, 1838, 593. — Ib. Bird.s Am. I, 1840, 193, pi. li. 

 Cotyle s. BoN. Consp. 1850, 342. — Cassin. — Brewer, N. Am. Ool. I, 1857, 106, 

 pi. iv, fig. 50 (eggs); —Baird, Birds N. Am. 1858, 313. — Lord, Pr. R. A. Inst. IV, 

 1864, 116 (Br. Columbia). — Cooper & Suckley, P. R. R. Rep. XII, ir, 186 (W. Terr.). 

 — Heermann, p. R. R. X ; Williamson's Rep. 36 (San Antonio, Tex. ; breeding). — 

 Cooper, Orn. Cal. I, 1870, 110. Stelgidopteryx s. Baird, Birds N. Am. 1858, 312 ; 

 Rev. 314. 



