212 BIRDS OF ILLINOIS. 



posed, 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." (BAIRD.) 



The chief peculiarity of this genus consists in the remarkable 

 roughness of the edge of the wing, said to occur also in Psalidoprocne 

 CAB., an African genus. This characterizes only the adult male and 

 older females, the young and many adult females having the web of 

 the outer primary soft, as in other swallows. 



Stelgidopteryx serripennis (Aud.) 



BOUGH-WINGED SWALLOW. 



Popular synonyms. Bough- winged Bank Swallow, or Sand Martin; Bridge Swallow. 

 Hirundo serripennis AUD. Orn. Biog. iv, 1838, 593; Synop. 1839, 37; B. Am. i, 1840, 193, pi. 51. 

 Cotyle serripennis BOIE, 1814. BAIKD. B. N. Am. 1858, 313; Cat N. Am. B. 1859, No. 230. 

 Stelgidopterjjx serripennis BALED, Review, 1865,314. COUES, Key, 1872, 114; Check List, 

 1873, No. 116; 2d ed. 1882, No. 164; B. N. W. 1874. 90; B. Col. VaL 1878, 438.-B. B. & R. 

 Hist. N. Am. B. i, 1874, 350, pi. 16, tig. 12. RIDGW. Nom. Am. B. 1881, No. 158. 



HAB. Whole of United States, except extreme northern border, and New England east 

 of the Connecticut Valley; northwest to British Columbia; wintering in Mexico and 

 Guatemala. 



"Sp. CHAE. (No. 32,269, male.) Above smoky brown, rather deeper on the head, perhaps 

 a little paler on the rump. Larger quills and tail-feathers dusky brown; the secondaries 

 and greater coverts sometimes lighter along their external edges. The under parts (for 

 about half the total length) from bill to and including breast, with the sides of body and 

 lining of wings, mouse-gray, rather lighter along the throat; the rest of under parts, in- 

 cluding crissum, white, the latter with the shafts sometimes dusky, and very rarely with 

 dusky blotches at the ends of the longer feathers. 



"Young birds (as in 1,120) differ in a tinge of reddish fulvous on the upper parts; the 

 wing-coverts, secondaries, and inner primaries margined more or less broadly with a 

 brighter shade of the same. The gray of the under parts is also washed with this color, 

 especially on the chin and across the breast. The hooks of the edge of the wing have not 

 yet become developed. 



"(No. 32.269, male, fresh specimen before being skinned.) Total length, 5.40; expanse of 

 wings. 12.20; wing from carpal joint, 4.50. 



"(No. 32,269, male, prepared specimen.) Total length, 5.20; wing,4.50; tail.2.25; depth of 

 fork, .15; difference of primaries, 2.28; length of bill from forehead, .40, from nostril, .24, 

 along gape, .56, width of gape, .43; tarsus, 45; middle toe and claw, .57; claw alone, .19; 

 hind toe and claw, .41; claw alone. .16." (Bist. If. Am. B.) 



In its general appearance as well as in habits, the Kough-winged 

 resembles so closely the Bank Swallow as to be not easily distin- 

 guished by the casual observer. It nests, like the latter species, in 

 holes dug into the banks of streams or ravines, usually, however, 

 in colonies by themselves, though not unfrequently mingling with 



