NORTH AMERICAN BIRDS. 
grasses, etc., in marshes (fresh- or salt-water), often 
upon “ windrows” of sea-weed. Eggs 1.78 X 1.23, 
ovate or short-ovate, varying from olive-buff to 
olive-brown, coarsely spotted or blotched with 
dark brown or blackish. Hab. Temperate North 
America, north to Manitoba, south, in winter, to 
Brazil........ 69. S. forsteri Nurr. Forster’s Tern. 
g. Inner web of outer tail-feather entirely white, the 
outer web dusky, in abrupt contrast. 
. Tarsus more than .65. 
Summer adult: Lower parts pale lavender-gray, 
or grayish white; whole top of head and nape 
deep black; rest of upper parts deep pearl- 
gray, the rump, upper tail-coverts, and greater 
part of tail pure white; bill bright vermilion- 
red, blackish at tip; feet (in life) rich orange- 
vermilion. Winter adult: Similar, but fore- 
head, crown, and anterior part of lores white, 
mixed with black on crown; entire lower 
parts pure white; bill and feet less intensely 
red. Young: Orbital region, occiput, and 
nape, dull black; crown mixed blackish and 
grayish white; forehead, lores, entire lower 
parts, upper tail-coverts, inner webs of rectri- 
ces, and tips of secondaries, white; rest of 
upper parts pale pearl-gray, the scapulars, 
interscapulars, and tertials, tipped with pale 
buff, and marked with a subterminal cres- 
centic spot, or lunule, of dusky brown; an- 
terior lesser wing-coverts dusky, forming a 
distinct bar across wing; bill brownish dusky, 
the base of mandible paler and more reddish; 
feet pale reddish. Downy young: Above pale 
fulvous or grayish buff (the precise shade 
very variable) coarsely and irregularly mar- 
bled with dusky, except on forehead; lower 
parts white, more or less tinged with buff or 
pale fulvous on sides and flanks, the throat 
and cheeks distinctly dusky, or grayish. 
Length 13.00-16.00, wing 9.75-11.75, tail 5.00- 
7.00 (forked for 3.50, more or less), culmen 
1.25-1.50, depth of bill at base about .33, tar- 
sus .66-.85. West usually a depression in 
sand or gravel near sea-shore. Eggs 2-4, 1.57 
X 1.17, averaging a little paler in ground- 
