704 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
KEY TO THE SUBSPECIES OF NEPHG@CETES NIGER. 
a. General color decidedly grayish. (Haiti; Cuba?) Nephcecetes niger niger (p. 704). 
aa. General color distinctly blackish or dark sooty. 
b. Smaller (wing averaging 154.5 in male, 150 in female) but tail longer (averaging 
66 in male, 58.5 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?) 
Nephecetes niger jamaicensis (p. 705). 
bb. 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.) 
Nepheecetes 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.)..........- Nepheecetes niger costaricensis (p. 710). 
NEPHECETES NIGER NIGER (Gmelin). 
BLACK SWIFT. 
Adult male.-—Pileum and hindneck deep grayish brown or sooty, 
passing into sooty blackish on back and other upper parts (the 
wings and tail very faintly glossed with bluish); chin 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 distinct whitish area bordering 
the upper edge of the velvety black lores; marginal under wing- 
coverts very narrowly margined terminally with pale grayish; bill 
black; iris dark brown; legs and feet dusky (in dried skin); 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 being a clear sooty brownish 
gray or grayish brown; in some specimens, the feathers of lower 
abdomen indistinctly tipped with whitish; length (skins), 138-156 
@ 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. 
