LARIDJi-LARIN.E: GULLS. 987 



dented with this color. Under parts mottled with white or rufous-white and dusky, throat 

 mostly immaculate. Primaries and tail brownish-black, the former tipped, latter subterminally 

 barred, and its outer feather mottled, with whitish. Nestlings in down : Gray, the upper parts 

 mottled with darker gray, and on the head spotted with black. Length 30.00; extent 65.00; 

 wing 19.00; bill above 2.50; rictus 3.50; height at nostril 0.85; at angle 0.95; tarsus 3.00; 

 middle toe and claw slightly less. This great wary bird, the dark rival of the Ice-Gull, inhabits 

 the Atlantic coasts of Europe and North America, ranging south coastwise in winter to Florida 

 and casually to the Bermudas, also to the Great Lakes, breeding beyond the U. S., especially 

 in Labrador. Found on the larger inland waters as well as coastwise. Nest on the ground, of 

 moss, grasses, and seaweed ; eggs 2 or 3, 2.90-3.10 X 2.1 5, pale drab or olive-gray, irregularly 

 blotched with dark brt)wn and blackish, with purplish or neutral-tint shell-spots. 

 L. schistisa'gus. (Gr. (txisto^, schistos, fissile, clcavable, that may be split, as slate, stone, or 

 shlstis, hence slate-colored; adyos, sagos, cloak, mantle.) Slaty-backed Gull. Adult: 

 White; mantle dark slate-gray. First primary with a long white tip and a gray wedge on 

 inner web; 2d with a subapical white spot on inner web only, and the gray wedge farthei 

 down ; 3d with the gray wedge reaching subapical spot ; no gray wedge on outer webs of first 4 

 primaries. Feet pinkish flesh-color. Bill yellow, with red spot on gonys. Iris yellowish 

 cream-color. Nearly the size of the last; length about 2(5.00; wing 17.00-18.00; culmen 

 2.25; depth of bill 0.85; tarsus 2.70; middle toe without claw 2.25. N. Pacific and Arctic 

 Oceans, chiefly on the Asiatic side, but also on the coast of Alaska. This Gull has been 

 variously called argentatus, cachinnans, fiiscescens, marinus, pelagicus, affinis, borealis, by 

 difl'erent authors, and named schistisagiis in the Auk, i, July, 1884, p. 231, and Bull. U. S. 

 Nat. Mus. No. 29, 1885, p. 67. See also Water Birds N. A. ii, 1884, p. 229 ; Proc. U. S. 

 Nat. Mus. .K, 1887, p. 119, pi. 8, fig. 1 ; Key, 3d ed. 1887, p. 892; Man. N. A. Birds, 1887, 

 p. 29; Nelson's Rep. Alaska, 1887, p. 53; Auk, 1893, p. 123; A. O. U. List, 2d ed. 1895, 

 p. 18, No. 48 ; Cat. Birds Brit. Mus. xxv, 1896, p. 258. 



L. occidenta'lis. (Lat. occidentalism western.) Western Herring Gull. Bill large, 

 very stout and deep; culmen unusually convex at end; angle strongly developed, making the 

 under outline doubly-concave. Feet large and stout ; tarsus equal to middle toe and claw. 

 Adult $ 9) summer plumage: Bill bright chrome-yellow; a vermilion spot, more or less 

 extensive, at angle. Mantle dark bluish-ash, almost slate-color; tips of secondaries and ter- 

 tials white, the line of demarcation distinct. Primaries : first 3 black throughout their exposed 

 portions, the outer one white for 1.75 at tip, crossed near end with an irregular black bar, the 

 shafts black; 2d without a white subapical spot, but its tip, and tips of all the others, white. 

 Legs and feet flesh-color. Approaching maturity : As in the proc^ding, but the upper parts 

 rather lighter, and the tail with an imperfect subterminal bar of black. Intormediate: 

 Bill much as in adult. White of head, neck, and under parts, more or less mottled with dusky ; 

 enll-blue of upper parts appearing in irregular patches ; most feathers tipped with light-gray. 

 Primaries and tail uniform blackish-brown, with scarcely lighter tips, the former without 

 spots. Young-of-the-year : Bill entirely black, rather shorter than in adults, but with great 

 comparative depth at angle. Everywhere deep blackish-brown, mottled with grayisii-white, 

 the feathers of the upper parts being tipped and edged with that color. Rump and upper tail- 

 coverts barred with whitish and dusky. Wings and tail as in the preceding. Winter plumage: 

 I'liis species seems to form an exception to the rule which obtains .so extensively amoiisj large 

 (lulls, since in winter the head and neck behind are not streaked with dusky in fully adult 

 i>irds. Dimensions of adults : Length 24.00; extent .55.00; wiii^' !('>. .">(); bill above 2..'tt); 

 along gape 3.10; height at nostril 0.75; width 0.40; height at an^leO.85; tarsus, and middle 

 toe and claw, 2.75. Pacific coast of North America, very common, breeding from Briti.sh Co- 

 liimbi.i to Lower California. This and 7>. glnuccscetus are the two commonest largo Gulls 

 aloiii: the I'acitic coast. Eggs usually 3, about 2. H5 X 1-JM), not distiiii;uishable from tho.so 



