BIRDS OF NORTH AND MIDDLE AMERICA. 668 



gra}^. Young grayish above, the feathers margined terminally with 

 pale fulvous or dull huffy 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 ahke). — Head and upper neck, all round, 

 imiform 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 

 an^ 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 ma.r- 

 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 grajnsh buffy, 

 this on tertials, longer scapulars, etc., preceded by submargmal 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; biU 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 tiUeul 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 A\'ith blackish; bill brownish, the ter- 

 minal third (approximate!}') darker. 



