POMARINE SKUA. 111 
Nestling in down —Smoky-grey, darker above and paler below, with indistinct 
darker blotches on the upper-surface. 
Nest.—None ; a shallow depression. 
£ggs—Clutch, two ; ground-colour dark stone, sparingly marked with blotches 
of brown, and a few dark grey ones round the middle ; axis 76 mm., diameter 52. 
Breeding-season—November. (Chatham Island, Macquarie Island.) 
Distribution and forms —Round the Sub-antarctic Circle. Probably many forms 
will be later differentiated, but Mathews only separated three, as: C.1. lonnbergi from 
New Zealand and its sub-antarctic Islands ; C1. intercedens Mathews, from Kerguelen 
Island, smaller than the preceding, with a large bill, wing average 410 mm. ; typical 
form 430 mm.; and C. /. clarkei Mathews from South Orkneys is a smaller form 
still, the wing generally under 400 mm. 
Genus COPROTHERES. 
Coprotheres Reichenbach, Nat. Syst. Vogel, p. v., 1852 (1853 ?). Type (by original designa- 
tion): Larus = (Lestris) pomarinus Temminck. 
Medium Skuas with stout bills, long wings, long tail with central pair of feathers 
elongated and twisted, but not attenuated, strong legs and feet. Differing from 
Catharacta in its smaller size, with a less stout bill and the elongation of the central 
tail-feathers, which are, however, broad, and from Stercorarius in its much larger 
size and stouter bill, stronger legs and feet and in lacking the attenuation of the 
longest central tail-feathers. As to proportions, it might be noted that the bill is 
just over one-tenth the length of the wing ; in the latter it is less, and in the former, 
it is more than one-eighth, and other items are in agreement as the wing is less than 
twice the length of the tail as in the latter, but in the former it is more. 
Coloration dark brown-black above with the under-surface more or less white. 
78. Coprotheres pomarinus.—POMARINE SKUA. 
[Lestris pomarinus Temminck, Manuel d’Orn., p. 514, (pref. dated 1814) 1815: Arctic Europe. 
Extra-limital.} 
Mathews, Vol. IT., pt. 5, pl. 123, Jan. 31st, 1913. 
Catarractes camtschatica Pallas, Zoogr. Rosso-Asiat., Vol. II., p. 312, 1827: Kamtschatka. 
Coprotheres pomarinus nutcheri Mathews, Austral Av. Rec., Vol. III., pt. 4, p. 72, July 21st, 
1917: Broken Bay, New South Wales. 
DIsTRIBUTION.—Siberia (breeding) migrating southward to Australia (visitor). Onespecimea 
preserved in Mathews’s collection. 
Adult male.—General colour of the upper-surface sooty-black including the 
crown of head, cheeks, back, wings, and tail; primary-quills black on the outer 
webs and tips, brown on the inner webs and white at the base, the shafts white, dark 
brown at the tips ; secondaries dark brown, white at the base ; tail dark brown with 
white shafts at the basal portion, the two middle feathers produced beyond the rest 
of the tail and twisted ; hind-neck and sides of neck straw colour; a band which 
encircles the fore-neck and lower hind-neck, is composed of white feathers barred 
with brown and fringed with white at the tips. This colour extends on to the sides 
of the body ; throat, breast, and abdomen white ; axillaries and under wing-coverts 
sooty-black like the vent and under tail-coverts ; bill horn brown ; tarsi and toes 
reddish-black. Total length 550 mm.; culmen 38, wing 366, tail 227, tarsus 53. 
Adult female.—Similar to the male. Nearly adult—General colour of the 
upper-surface brown with pale edges and sometimes white bars to the feathers, 
crown of head rather paler than the back with buff edgings to the feathers ; sides 
of the crown, nape, and hind-neck pale brown with buffy-white bars and 
edgings to the feathers; upper back and scapulars dark brown, the feathers 
