46 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



KEY TO THE SPECIES AND SUBSPECIES OF PETROCHELIDON. 



a. Crown and occiput glossy blue-black or greenish black. (Adults.) 



h. Sides of head, chin, and throat chestnut or cinnamon, forehead with a broad 

 and sharply defined patch of chestnut, cinnamon-brown or whitish. 

 c. Sides of head, chin, and throat deep chestnut, the latter with a blackish 

 patch on lower portion. {Pctrochelidon bmifrons. ) 

 d. Frontal patch whitish or pale cinnamon-brown, conspicuously different 

 from the chestnut of sides and under parts of head. 

 e. Larger (wing of adult male 105-115, averaging 108.6); forehead usually 

 soiled white. (Greater part of North America; Central America and 

 parts of South America in winter. ) 



Petrochelidon lunifrons lunifrons, adults (p. 47) 

 ee. Smaller (wing of adult male 100-104, averaging 102.1); forehead light 

 cinnamon or fawn color. (Southwestern Texas, west of Pecos River, 

 south to Vera Cruz; Costa Rica and Isthmus of Panama in winter.) 



Petrochelidon lunifrons tachina, adults (p. 50) 

 dd. Frontal patch deep cinnamon-rufous or chestnut, like sides of head, etc. 

 (Size of P. I. tachina.) (Western portion of Mexican plateau, north to 

 southern Arizona; Guatemala? Costa Rica?) 



Petrochelidon lunifrons melanogaster, adults (p. 51 ) 

 cc. Sides of head, chin, and throat much paler chestnut, cinnamon-rufous, or 

 whitish tinged with cmnamon-rufous; no black patch on throat. {Petro- 

 cJielidon fulva .) 

 d. Larger (wing averaging more than 103, tail averaging more than 45); sides 

 of head, throat, sides, etc., less deeply cinnamon-rufous. 

 e. Larger (wing averaging more than 107, tail more than 48, tarsus and 

 middle toe 12 or more); rump paler cinnamon-rufous; sides and flanks 

 more faintly tinged with cinnamon-rufous. (States of Coahuila and 

 Tamaulipas, northeastern Mexico. ) 



Petrochelidon fulva pallida, adults (p. 56) 

 ee. Smaller ( wing averaging less than 104, tail less than 46, tarsus and mid- 

 dle toe less than 12); rump deeper cinnamon-rufous or chestnut; sides 

 and flanks more strongly tinged with cinnamon-rufous. (Cuba; 

 Haiti?; accidental on Dry Tortugas, Florida.) 



Petrochelidon fulva fulva, adults (p. 53) 



dd. Smaller (wing averaging less than 103, tail less than 45); sides of head, 



throat, sides, etc., deeper cinnamon-rufous. (Jamaica; Porto Rico; 



northern Yucatan?) Petrochelidon fulva poeciloma, adults (p. 54) 



hh. Sides of head, chin, and throat white; forehead with a narrow and very 

 indistinct patch of dull chestnut or dusky brown. (Peru. ) 



Petrochelidon rufocoUaris (extralimital)« 

 aa. Crown and occiput dull black or dusky. (Young.) 



b. Rump vinaceous-cinnamon, throat mixed dusky and chestnut. [Petrochelidon 

 lunifrons, young. ) 



aHirundo rufocoUaris Peale, Rep. U. S. Expl. Exped., viii. Mam. and Orn., 1848, 

 175, "pi. xlix, fig. 1" (near Callao, Peru; type in coll. U. S. Nat. 'Mus.).— Petro- 

 chelidon ruficollaris Baird, Review Am. Birds, 1865, 292, footnote; Sharpe, Cat. Birds 

 Brit. Mus., X, 1885, 196, pi. 3 (Lima, Peru); Sharpe and Wyatt, Mon. Hirund., 1894, 

 567, pi. 108. 



