BlEDS OF NORTH AND MIDDLE AMERICA. 57 



ginate (depth of emargination less than length of exposed culmen). 

 Tarsus longer than middle toe (without claw), only the extreme upper 

 portion (if any) feathered; middle toe united to outer toe by about half 

 to nearly the whole of its basal phalanx, to the inner by about half the 

 basal phalanx; claws of lateral toes scarcely reaching to base of middle 

 claw; claws rather small, that of the hallux shorter than the digit. 



Adult male with barbs of outer web of outermost primary stiffened 

 and abruptly recurved at tip, causing a file-like roughness when the 

 finger is drawn along the edge of the quill from base toward tip. 



Coloration. — Above plain grayish brown (paler on the rump in some 

 species), beneath paler grayish brown, becoming white on abdomen 

 and posteriorly, the throat sometimes cinnamon or buffy and some 

 species with a large blackish spot at end of longer tail-coverts. 



Nidification. — Nest in holes of banks, more rarely of bridges or 

 buildings, composed of soft grasses, feathers, etc.; eggs immaculate 

 white. 



Range. — Warm-temperate, and tropical continental America. (Sev- 

 eral species.) 



In the roughened edge of the outermost primary this genus agrees 

 with Psalidoprocne Cabanis, of western and southern Africa, but in 

 other respects is so exceedingly dissimilar that I seriously doubt their 

 close relationship, notwithstanding Dr. Sharpe has placed them 

 together in a "subfamily," Psalidoprocninae, entirely apart from other 

 Swallows. 



KEY TO THE SPECIES AND SUBSPECIES OP STELQIDOPTEBYX. 



a. Tertials without cinnamomeous margins. (Adults.) 

 h. Under tail-coverts entirely white. 

 c. Pileum not distinctly darker than back; tertials without white margins; chin 

 and throat pale brownish gray. (Greater part of United States and south- 

 ward to Costa Rica.) St&lgridopteryx serripennis, adults (p. 58) 



cc. Pileum distinctly darker than back; tertials margined with white; chin and 

 throat pale cinnamon or cinnamon-buff. (Southwestern Mexico to Chiriqui.) 



Stelgidopteryx salvini, adults (p. 62) 



56. Under tail-coverts not entirely white, the two longer feathers having a terminal 



or subterminal spot of dusky or blackish. 



c. Rump concolor with back, the latter very dark sooty grayish brown; chin and 



throat pale brownish gray, concolor with chest and sides. (Tabasco and 



Yucatan, southeastern Mexico; eastern Guatemala. ) 



Stelgidopteryx ridgwayi, adults (p. 61) 

 cc. Rump pale brownish gray or whitish, very different from grayish brown of 

 back; chin and tliroat pale cinnamon or cinnamon-buff. (Costa Rica to 

 Colombia, Venezuela, and Trinidad.) 



Stelgidopteryx rnfioollis« uropygialis, adults (p. 63) 



'^Stelgidopteryx ruJkoUis ruficollis belongs to southern Brazil, etc., and differs from 

 S. T. uropygialis in having the rump concolor with the back, and in larger size. The 

 South American bird varies considerably according to geographic area, and undoubt- 



