t04 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



KEY TO THE SUBSPECIES OF NEPHCECETES NIGER. 



a. General color decidedly grayish. (Haiti; Cuba?) Nephoecetes nigerniger (p. 704). 

 aa. General color distinctly blackish or dark sooty. 



h. Smaller (wing averaging 154.5 in male, 150 in female) but tail longer (averaging 

 66 in male, 68.5 in female); female with white tips to feathers of posterior 

 under parts much less distinct. (Jamaica; Porto Rico?; Dominica?; Guade- 

 loupe?; St. Vincent?; Martinique?; British Guiana?) 



Nephoecetes niger jamaicensis (p. 705). 



66. Larger (wing averaging 159 or more in male, more than 157 in female) but 



tail shorter (averaging not more than 61 in male, less than 52 in female). 



c. Larger (wing averaging 165.8 in male, 162 in female), coloration slightly 



paler; female with white tips to feathers of posterior under parts averaging 



narrower. (British Columbia to southern Mexico.) 



Nephcecetes niger borealis (p. 707). 



cc. Smaller (wing averaging 159 in male, 157.1 in female); coloration slightly 



darker; female with white tips to feathers of posterior under parts averaging 



broader. (Costa Rica.) Nephoecetes niger costaricensis (p. 710). 



NEPH(ECETES NIGER NIGER (Gmelin). 



BLACK SWIFT. 



Adult male.'^ — Pileum and hindneck deep grayish browii or sooty, 

 passing into sooty blackish on back and other upper parts (the 

 wings and tail very faintly glossed with bluish); chm and throat 

 much lighter grayish brown passing into much darker sooty on under 

 parts of body and under tail-coverts (the color slightly darker than 

 that of pileum); feathers of forehead and crown narrowly margined 

 at tip with grayish white, these whitish tips much broader on sides 

 of forehead, blending on edge into a distmct whitish area bordering 

 the upper edge of the velvety black lores; margmal under wing- 

 coverts very narrowly margined terminally with pale grayish; bill 

 black; iris dark brown; legs and feet dusky (in dried sldn); length 

 (skins), 155-158 (156.5); wing, 151-156 (153.5); tail, 62-63 (62.5) 

 (forked for 12); exposed culmen, 6-7 (6.5); tarsus, 12; middle toe,' 

 8.5-9 (8.7).^ 



Adult female. — Similar to the adult male but tail less emarginate 

 (nearly truncate), under parts paler, especially under parts of body 

 and under tail-coverts, which are nearly concolor with the throat, 

 the general color of the under parts bemg a clear sooty brownish 

 gray or grayish brown; m some specimens, the feathers of lower 

 abdomen mdistinctly tipped with whitish; length (skins), 138-156 



a Described from a Cuban specimen, no adult male from Santo Domingo or Haiti 

 being available. This Cuban specimen is much paler in coloration than even adult 

 females of the Jamaican form, and, though slightly darker (especially on the under 

 parts) than adult females from Santo Domingo I believe will be found referable to 

 the same form. 



b Two specimens. * 



