668 BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 
X[ema] sabinei Newson, Bull. Essex Inst., viii, 1876, 147 (near Chicago, Illinois, 
April, 1873). 
Chema sabinii Rercuenow, Journ. fiir Orn., 1889, 188; Syst. Verz. Vg. Deutschl., 
1889, 62.—Harrert, Katal. Vogelsamml. Senckenb., 1891, 248. 
[Chema] sabinii Heinz and Rutcuenow, Nom. Mus. Hein. Orn., 1890, 360. 
Zema sabini Hoisé.t, Naturhist. Tidsskr., iv, 1843, 423 (Greenland). 
Gavia sabinii Maccmurvray, Man. Brit. Orn., ii, 1842, 241; Brit. Birds, v, 1852, 
607. 
Xema collaris (not of Schreibers) Lzacu, in 8vo ed. Ross’s Voy. Baffin Bay, ii, 
1819, 164.—OLpHe-GaLuiarD, Contr. Faune Eur. Occid., fasc. x, 1886, 108. 
Larus minutus (not of Pallas) Bousmann, Naumannia, 1852, Bd. ii, Heft iii, 35 
(Westphalia, Germany). 
Genus RHODOSTETHIA Macgillivray. 
Rossia (not of Owen, 1835) Bonaparte, Geog. and Comp. List, 1838, 62. (Type, 
Larus roseus Macgillivray.) 
Rhodostethia Maccitttvray, Man. Brit. Orn., ii, 1842, 252. (Type, by original 
designation, Larus rossii Richardson=L. roseus Macgillivray.) 
Rhodestethia (emendation?) TaczAnowsk1, Mém. Acad. St. Petersb., xxxix, 1893, 
1048. 
Very small Laride (wing 241-261 mm.) with tail cuneate or grad- 
uated (the middle pair of rectrices much longer than lateral pair), 
exposed culmen only about two-thirds as long as tarsus, the adults 
with head, neck, under parts, etc., white (more or less tinted with 
pink), in summer with a black collar round neck. 
Bill relatively very small, much shorter .than head, the exposed 
culmen only about two-thirds as long as tarsus, its upper and lower 
outlines straight and nearly parallel for basal two-thirds, beyond 
which former is strongly decurved, the latter decidedly ascending 
terminally, in a straight line from angle of gonys, the last not promi- 
nent. Wing long and pointed, the longest primary (outermost) ex- 
ceeding distal secondaries by about three-fifths the length of the wing. 
Tail less than (sometimes nearly) half as long as wing, distinctly 
cuneate or graduated, the middle pair of rectrices longest and much 
longer than lateral pair; tail coverts very long, extending almost to 
tip of middle rectrices. Tarsus much longer than middle toe without 
claw, less than one-eighth as long as wing, rather stout, the some- 
what roughened bare portion of tibia very short; hallux well-devel- 
oped, though small, with claw relatively large and strongly curved. 
Coloration. Adults with back, scapulars, and wings uniform very 
pale (pallid) neutral gray; rest of plumage immaculate white, usually 
suffused (often deeply) with pure eosine pink, the neck encircled, in 
summer, by a narrow black collar. Young with pileum, hindneck, 
back and scapulars clouded with dusky or sooty blackish, the feathers 
of lower back, tipped with buffy; tail white, the six middle rectrices 
tipped with sooty blackish. 
Range.—Circumpolar regions, south in winter, casually, to Eng- 
land, Faroe Islands and Helgoland. (Monotypic.) 
