BIRDS OF NORTH AND MIDDLE AMERICA. 451 
Anisoramphe« Dumont, Dict. Sci. Nat., iv, 1805, 173. (Alternative substitute 
name for Rynchops?) 
(Generic characters same as Family characters.) 
KEY TO THE SPECIES AND SUBSPECIES OF RYNCHOPS. 
a. Under wing-coverts and axillars white or very pale brownish gray, in abrupt and 
conspicuous contrast with black along edge of wing; secondaries very broadly 
tipped with white; under tail-coverts white; lateral rectrices white or mostly so. 
(Rynchops nigra.) 
b. Axillars and under wing-coverts pure white; smaller (wing 350-401 in male, 
338-358 in female; culmen 63-72 in male, 52-57 in female). (Atlantic and 
Gulf coasts of United States, south in winter to Yucatan, Trinidad, etc.) 
Rynchops nigra nigra (p. 451). 
bb. Axillars and under wing-coverts pale brownish gray or tinged with that color, 
larger (wing 385-412 in male, 382 in female; culmen 74.5-83 in male, 66 in 
female). (Atlantic coast of South America and Pacific coast of Central 
America and Mexico.).......-.-.------- Rynchops nigra intercedens (p. 453). 
aa. Under wing-coverts and axillars brownish gray, not strongly contrasted with 
blackish along edge of wing; secondaries very narrowly tipped with white; under 
tail-coverts brownish gray margined with white; lateral (as well as middle) 
rectrices deep brownish gray narrowly edged with white. (Atlantic and Pacific; 
coasts of South America; casual in Yucatan.).. Rynchops cinerascens (p. 455)- 
RYNCHOPS NIGRA NIGRA (Linneus). 
BLACK SKIMMER. 
Adults in summer (sexes alike).—Forehead, lores, suborbital and. 
malar regions, and entire under parts (including axillars and under 
_ wing-coverts), lateral upper tail-coverts, and broad tips to second- 
aries and proximal primaries, immaculate pure white; rest of plumage 
(except tail), including auricular region, uniform black or sooty black; 
tail mostly white, the middle pair of retrices grayish brown edged 
with white, the remaining retrices more or less tinged at tips with 
the same; basal half (approximately) of bill bright vermilion red (in 
life), the mandible more scarlet, passing into orange or yellow on 
tomium, the terminal half black; iris dark brown; legs and feet rich 
orange-vermilion (in life). 
Adults in winter—Similar to summer adults but the black duller 
and more brownish and interrupted by a broad collar of white across 
lower hindneck. 
Young.—Upper parts light buff, each feather with a central spot. 
of blackish, these spots largest on scapulars; lores and suborbital 
region uniform pale buff, the former, however, with a dusky space 
immediately in front of eye; greater wing-coverts blackish gray or 
grayish black, tipped with white; secondaries white for most of their 
exposed portion; primaries blackish, the fourth, fifth, and sixth (from 
outside) margined terminally with light buff, the four inner (proximal) 
@"Avnoos, unequal; paudos, beak. (Richmond.) 
