BIRDS OF NORTH AND MIDDLE AMERICA. 605 



Larus maculatm (not of Brunnich, 1764) Boddaert, Tabl. PI. Enl., 1783, 16 

 (based on Le Grisard Daubenton, PI. Enl., pi. 266; Le Goeland varie ou Le 

 Grisard Buffon, Hist. Nat. Ois., xvi, 200; Brisson, Orn., \'i, 167). 



Lams giganteas Benicken, Ann. Wettorau. Gesel., iii, 1812, 140 (Baltic Sea;= 

 young).— Temminck, Man. d'Orn., 1815, 490, footnote. 



Larus maTimus (not of O'Reilly, 1818) Leach, Syst. Cat. Brit. Mas., 1816, 40. — 

 Brehm, Beitr. Vogclk., iii, 1822, 741; Lehrb., 1824, 733; Isis, 1830, 993; 

 Vog. Deutschl., 1831, 728; Xaumannia, 1855, 294; Vogelf., 1855, 337.— 

 Blagg, Ibis, 1893, 356 (Shetland Islands, breeding; habits). 



L[arus] mulleri Brehm, Isis, 1830, 993 (nomen nudum); Naumannia, 1855, 294. 



Larus mulleri Brehm, Vog. Deutchl., 1831, 729, (Iceland in winter to the German 

 and Holland coasts); Vogelf., 1855, 337. 



L[arus]fabricii BiIehm, Isis, 1830, 993 {nomen nudum). 



Larus fabricii Brehm, Vog. Deutschl., 1831, 730 (Greenland and in winter to 

 coast of middle Europe); Vogelf., 1855, 337; Naumannia, 1855, 294. 



Larus nigripallus Dubois, PI. Col. Ois. Belg., iii, 1860, 240. 



Larus albus Mijllkr, Natursyst., 8uppl., 1776, 108 (Europe; based on Le Grisard 

 Daubenton, PI. Enl., pi. 266). 



LARUS SCHISTISAGDS Stejneger. 



SLATY-BACKED GULL. 



Similar to L. marinus, but sliglitly smaller; back, scapulars, and 

 wings decidedly ligliter 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, al)out 10 

 mm. from tip; second (from outside) with the terminal white spot 

 only about 10 mm. in extent, but the inner web with a lai'ge oval 

 spot of white, about 23 mm. long, within the black area ; third with 

 the white terminal 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, abrupt!}' 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 



