63 
of the United States. 
Wings extremely long ; first primary a little shorter than 
the second, which is longest Tail of ten feathers. 
F emale and young hardly differing from the adult male. 
Moult annually. 
Build in clefts of high rocks and buildings ; nests con- 
structed of small twigs, agglutinated together by a viscous 
substance secreted in the mouth. Flight horizontal and very 
rapid ; rise from the ground with difficulty on account of 
their very short feet: cling firmly by their claws. 
Spread all over the globe. 
70. Cypselus pelasgius, Temm. Deep sooty-brown ; chin and 
line over the eye dull whitish ; wings extending one and a 
half inches beyond the tail ; tail even, feathers mucronate. 
Chimney Swallow , Hirundo pelasgia , fVils. Jim. Orn . v. 
p. 48- pl - 39 - fig- l. 
Inhabits chimneys in all the United States during summer : 
common : does not extend very far north. 
15. HIRUNDO. 
Hirundo , L. Briss. Gm. Lath. 111. Cuv. Vieill. Temm. 
Ranz. 
Bill triangular, cleft nearly to the eyes, with a few scat- 
tered bristles at the base ; upper mandible notched ; lower 
shorter, a little narrower, acute, and nearly straight to the 
tip : nostrils basal, oblong, posteriorly closed by a mem- 
brane, and covered by the frontlet feathers : tongue short, 
cartilaginous, bifid at tip. Tarsus short, slender ; middle 
toe longer than the subequal lateral ones, united with 
the outer to the first articulation ; inner toe free, generally 
longer than the hind toe, which is not versatile : middle toe 
nail largest. First primary longest. Tail of twelve feathers, 
almost always forked. 
Female and young often resemble the adult male. Moult 
annually. 
