BIRDS OF NORTH AND MIDDLE AMERICA. 687 
Genus AERONAUTES Hartert. 
Aéronautes? Hanrert, Cat. Birds Brit. Mus., xvi, 1892, 459. (Type, Cypselus 
melanoleucus Baird.) 
Medium-sized Cypseline (length, about 135-152 mm.) with toes 
(as well as tarsus) feathered, outer and middle toes directed forward 
on line with axis of tarsus, tail forked for less than one-fourth its 
length, and feathers of pileum and under parts distinctly outlined 
(broadly rounded). 
Tail about half as long as wing, moderately forked (for less than 
one-fourth its length), the lateral rectrices not attenuated terminally, 
the outermost pair little if any longer than next pair; tenth (outer- 
most) primary shorter than ninth, but equal to or longer than eighth; 
feet very stout, the toes short and thick and claws strong; tarsi and 
toes feathered (except on soles of latter); middle toe slightly longer 
than tarsus, but scarcely longer than inner toe, which is slightly 
longer than the outer; hallux very short, inserted laterally on inner 
side of foot. 
Coloration.—Dusky above and on lateral under parts; throat, chest, 
median line of breast and abdomen, and a patch on upper flanks 
or sides of rump, dull white. 
NMidification.—Nest placed in crevices of vertical cliffs or walls of 
old buildings, composed of feathers, bark, grass, wool, cotton, etc., 
glued to its support by salivary excretion. 
AERONAUTES MELANOLEUCUS (Baird). 
WHITE-THROATED SWIFT. 
Adults (sexes alike).—Pileum and hindneck grayish brown to very 
dark sooty brown, sometimes uniform but usually becoming paler on 
forehead, and with feathers indistinctly margined with paler, espe- 
cially on frontal region, the projecting edges of crown dull whitish, 
forming a distinct narrow superciliary streak; back, scapulars, wing-cov- 
erts, rump, and upper tail-coverts plain sooty blackish, the tail similar 
but rather more sooty (less blackish); a large patch of white or 
brownish white on each side of rump, more or less pointed anteriorly; 
remiges dark sooty brown or sooty blackish, the secondaries broadly 
tipped on outer web with dull or brownish white, the inner webs of 
primaries passing into pale grayish brown on edges (except on longer 
quills); a dusky spot immediately in front of eye, the loral region 
otherwise whitish; auricular and postocular regions sooty grayish 
brown; suborbital and malar regions, chin, throat, chest, and median 
portion of breast and abdomen white (usually dull or more or less 
tinged with brownish); sides and flanks (broadly) and under tail- 
coverts plain very dark sooty brown or sooty black; feathers along 
@ ’Ajo, air; vabtye, a sailor, (Richmond.) 
