BIRDS OF NORTH AND MIDDLE AMERICA. 605 
Larus maculatus (not of Brinnich, 1764) Bopparrt, Tabl. Pl. Enl., 1783, 16 
(based on Le Grisard Daubenton, Pl. Enl., pl. 266; Le Goeland varié ou Le 
Grisard Buffon, Hist. Nat. Ois., xvi, 200; Brisson, Orn., vi, 167). 
Larus giganteus Benicken, Ann. Wetterau. Gesel., iii, 1812, 140 (Baltic Sea;= 
young).—Temminck, Man. d’Orn., 1815, 490, footnote. 
Larus maximus (not of O'Reilly, 1818) Luacu, Syst. Cat. Brit. Mus., 1816, 40.— 
BreuM, Beitr. Vogelk., iii, 1822, 741; Lehrb., 1824, 733; Isis, 1830, 993; 
Vég. Deutschl., 1831, 728; Naumannia, 1855, 294; Vogelf., 1855, 337.— 
Buaaa, Ibis, 1893, 356 (Shetland Islands, breeding; habits). 
Larus] milleri Bren, Isis, 1830, 993 (nomen nudum); Naumannia, 1855, 294. 
Larus millerti Breum, Vég. Deutchl., 1831, 729, (Iceland in winter to the German 
and Holland coasts); Vogelf., 1855, 337. P 
Efarus] fabricit Brenm, Isis, 1830, 993 (nomen nudum). 
Larus fabricti Breum, Vég. Deutschl., 1831, 730 (Greenland and in winter to 
coast, of middle Europe); Vogelf., 1855, 337; Naumannia, 1855, 294. 
Larus nigripallus DuBois, Pl. Col. Ois. Belg., iii, 1860, 240. 
Larus albus Mtuirr, Natursyst., Suppl., 1776, 108 (Europe; based on Le Grisard 
Daubenton, Pl. Enl., pl. 266). 
LARUS SCHISTISAGUS Stejneger. 
SLATY-BACKED GULL. 
Similar to L. marinus, but slightly smaller; back, scapulars, and 
wings decidedly lighter and less sooty (much as in L. occidentalis, 
but averaging decidedly darker), and first (outermost) primary, as 
well as second and third, with a distinct gray ‘‘wedge”’ on inner web. 
Adults in summer (sexes alike)—Head, neck, rump, upper tail- 
coverts, tail, and entire under parts, including axillars and under 
wing-coverts, immaculate pure white; back, scapulars, and wings 
uniform deep gray (neutral gray to deep neutral gray), the secondaries 
and tertials rather broadly tipped with white, the proximal primaries 
more broadly and abruptly tipped with white; four outer primaries 
with outer webs black, or slaty black, becoming more grayish basally, 
their inner webs for the greater part deep neutral gray or dull slate- 
gray, but abruptly blackish subterminally; outermost primary 
abruptly tipped with white, for about 53.5 mm. (measured along 
shaft), both webs with a small spot of blackish at edges, about 10 
mm. from tip; second (from outside) with the terminal white spot 
only about 10 mm. in extent, but the inter web with a large oval 
spot of white, about 23 mm. long, within the black area; third with 
the white termina] spot about the same size as that on the second, 
the inner web with a grayish white space, commencing about 40.5 
mm, from tip, abruptly defined, with a strongly convex outline, 
against the subterminal black area, but not distinctly contrasted 
with the gray of basal portion; fourth primary similar to third, but 
the white space on inner web more distinct and commencing only 
about 33 mm. from tip; fifth similar, but with white space on inner 
web still larger and nearer to tip (about 25.5 mm.), and the outer 
web deep neutral gray or dull slate-gray to within about 38 mm. of 
