STERCORARIUS. 21 
a’. Axillars and under wing-coverts sooty, with little or no rufous. 
b'. Below grayish brown, with more or less distinct lighter, more cinnamon- 
colored, spots or dashes on fore-neck and chest. Adult: Dull brown, the 
scapulars, interscapulars, and wing-coverts striped medially with pale 
cinnamon, the neck streaked with the same; lower parts indistinctly 
striped with grayish brown and pale cinnamon, the former prevailing 
(sometimes uniform). Sometimes (in melanistic specimens?) uniform 
dusky or sooty brown, except white wing-spot. Young: Similar to adult, 
but more distinctly streaked with yellowish, especially on head and neck. 
Downy young (of M. skua): Uniform “brownish or cinnamon-gray .. . 
rather darker in color on the upper parts than on the under surface of the 
body.” (Dresszr.) Length about 22.00, wing 15.75-16.15 (15.91), cul- 
men 2.05-2.10 (2.06), depth of bill at base .80-.88 (.82), tarsus 2.40-2.75 
(2.63), middle toe 2.15-2.55 (2.40). Eggs 2-3, 2.74 * 1.96, ovate or 
short-ovate, light brown or olive, rather sparsely blotched and spotted 
with deep brown. Had. Coasts and islands of North Atlantic, south to 
Spain and (casually) Massachusetts; California ? 
35. M. skua (Britwy.). Skua, 
6. Darker colored, larger, and with stouter bill; under parts uniform dark 
sooty, the neck however sometimes streaked with yellowish; wing 
16.05-16.90 (16.29), culmen 2.20-2.85 (2.38), depth of bill at base .95-1.00 
(.98), tarsus 2.70-3.20 (2.95), middle toe 2.55-2.80 (2.67). Hab. Antarctic 
seas, north to Cape of Good Hope and Cape Horn. 
M. antarcticus (Lazss.). Antarctic Skua? 
a. Axillars and under wing-coverts chiefly deep cinnamon. 
Lower parts uniform dull rusty or cinnamon. 
M. chilensis (Bonap.). Chilian Skua? 
Genus STERCORARIUS Brisson. (Page 20, pl. VIL, fig. 2.) 
Eggs 2-3, ovate or short-ovate, ground-color varying from pale greenish olive 
and pale brown to very deep olive, relieved by a greater or less amount of spotting 
of deep brown, usually mixed with stone-grayish. 
Species. 
a, Culmen 1.45 or more, tarsus 2.00 or more, wing usually more than 13.50; length- 
ened middle tail-feathers broad and rounded at ends. Light phase, adult : Top 
and sides of head, with upper parts, sooty slate or dusky; rest of head and 
neck, including nape, together with lower parts, white, the ear-covert region 
tinged with straw-yellow, and the lower tail-coverts slaty. Young: Head, 
neck, and lower parts dull buff, everywhere barred with dusky ; upper parts 
brownish dusky, the feathers of back, etc., tipped with buff, the rump and 
upper tail-coverts spotted with same. Dark phase, adult : Entirely dark sooty 
1 Lestris antarcticus Lxss., Traité Orn. 1831, 616. Megalestris antarcticus GouLn, P. Z. S. 1859, 98. 
2 Leatrie antarcticus, var. b. chilensis BonaP., Consp. ii, 1857, 207. 
