BIRDS OF NORTH AND MIDDLE AMERICA. 662 
gray. Young grayish above, the feathers margined terminally with 
pale fulvous or dull buffy and with a dusky submargin and tail with 
a broad subterminal band of black. 
Range.—Circumpolar regions, southward in winter to Bermudas, 
Texas, Peru, etc. (Monotypic.) 
XEMA SABINI (J. Sabine). 
SABINE’S GULL. 
Adults in summer (sexes alike).—Head and upper neck, all round, 
uniform dark gray (between deep neutral gray and dark quaker 
drab), bordered below by a narrow but distinct collar of black, 
widest behind; lower neck, entire under parts, lower rump, upper 
tail-coverts, tail, most of exposed portion of secondaries and greater 
wing-coverts, and proximal primaries immaculate white, the under 
parts sometimes tinged with eosine pink, the white of secondaries 
and greater wing-coverts shading into gray basally; back, scapulars, 
upper rump and wing-coverts (except greater) uniform gray (between 
light neutral gray and light mouse gray); four outer primaries 
black broadly tipped with white, their inner webs broadly mar- 
gined with the same; fifth primary (from outside) with greater part 
of inner web and distal portion of outer web (for about 44-45 mm.) 
white, the remainder black; border of wing, from carpal joint back- 
ward to and including primary coverts and alula uniform black; bill 
black with terminal portion, abruptly, yellowish; naked orbital 
ring red; iris dark brown; legs and feet dusky gray (blackish in 
dried skins). 
Adults in winter.—Similar to summer adults, but head and neck 
mostly white, only the occiput, nape, and auricular region dark 
grayish. 
Young.—Upper parts deep brownish gray or grayish brown, the 
feathers margined terminally with pale fulvous or light grayish buffy, 
this on tertials, longer scapulars, etc., preceded by submarginal line 
of dusky; remiges and greater coverts as in adults; tail white with a 
broad subterminal band of black, the tip, narrowly, white or pale 
fulvous; upper tail-coverts, entire under parts, and most of head and 
neck white; bill dusky, more brownish basally; legs and feet light 
brownish (in dried skins). 
Downy young.—General color deep brownish buff or avellaneous, 
fading into pale dull buff (nearly tilleul buff) on breast and abdomen; 
crown and occiput with irregular spots of black, smaller anteriorly; 
no spots on lateral or under portions of head; back, etc., irregularly 
spotted, marbled or clouded with blackish; bill brownish, the ter- 
minal third (approximately) darker. 
