110 A MANUAL OF THE BIRDS OF AUSTRALIA. 



delicate birds to stout heavy forms. They have the leg muscle formula of the Gulls 

 but differ in the presence of long caeca and the absence of the expansor secundariorum. 

 The coracoids are separated whereas in the preceding they are in contact. The 

 most interesting feature, however, is the differentiation of the Antarctic forms as 

 to the skull and also in connection with the syrinx. In skull characters the Antarctic 

 Skuas are more Pluvialine than Larine and the syrinx is also of the former nature. 

 No detailed comparison between these and Stercorarius appears to have been 

 instituted. 



Genus CATHARACTA. 



Catharacta Briinnich, Ornith. Boreal., p. 32, (pref. Feb. 20th) 1764. Type (by subsequent 

 designation, Reichenbach, Nat. Syst. Vogel, p. v., 1852 (? 1853): Catharacta skua Briinnich. 

 Pomarinus G. Fischer, Nat. Mus. Naturg. Paris, Vol. II., p. 185, (pref. March 6th) 1803. 

 Type (by monotypy) : Pomarinus fuscus = C. skua Briinnich. 



Megakstris Bonaparte, Comptes Rendus Acad. Sci. Paris, Vol. XLIIL, p. 643, Sept. 1856. 

 Type (by monotypy): Stercorarius catarrhactes = C. skua Briinnich. 



Buphagus Coues, Proc. Acad. Nat. Sci. Philad., 1863, p. 124, May. Type (by original designa- 

 tion) : Catharacta skua Briinnich. 

 Not Gray, Cat. Gen. Subgen. Birds, p. 129, 1855. 



Largest Skuas with stout powerful hooked bills, long wings, long wedge-shaped 

 tail and strong legs and feet with stout hooked claws, the inner claw peculiarly 

 developed. The bill has a horny cere, extending half way along the upper mandible, 

 overhanging the nostrils which appear as elongately oval apertures ; the tip of the 

 mandible is strongly hooked, and the gonys is not very pronounced. The wing is 

 long and the square tail is about two-fifths the length, the central feathers being 

 normal and not elongated in any way. The legs are very strong, and the feet with 

 very broad webs, the claws very hooked, the inner claw powerfully and abnormally 

 so, the hind -toe small. 



Coloration uniform dusky above and below. 



77. Catharacta lonnbergi. ANTARCTIC SKUA. 



Gould, Vol. VII., pi. 21 (pt. xxxv.), Dec. 1st, 1848. Mathews, Vol. II., pt. 5, pL 122, Jan. 

 31st, 1913. 



Catharacta antarctica lonnbergi Mathews, Nov. Zool., Vol. XVIII., p. 212, Jan. 31st, 1912: 

 New Zealand Seas. 



DISTRIBUTION. Southern Australian Seas. 



Adult male. General colour above dark brown, inclining to blackish on the 

 wings ; some of the scapulars fringed and mottled with white, as also some of the 

 upper tail-coverts ; wing-coverts uniform dark brown like the bastard-wing and 

 primary -coverts ; primary-quills white at the base, dark brown or blackish at the 

 tips, the shafts for the greater part white ; secondaries and tail-feathers dark brown, 

 white at the base ; head and neck all round, rufous-brown like the under-surface 

 of the body ; the feathers on the hind -neck and sides of the neck lanceolate in form 

 and show glossy shaft-streaks ; under wing-coverts and axillaries darker than the 

 abdomen and more glossy ; a short, narrow streak of white below the eye ; bill 

 black ; iris dark brown ; feet black. Total length 690 mm. ; culmen (exp.) 57, 

 wing, 433, tail 170, tarsus 78. 



Adult female. Similar to the adult male. Total length 610 mm . ; culmen 56, 

 wing 410, tail 155, tarsus 77. 



Captain Hutton says : " Sometimes the feathers of the back of the neck are 

 finely streaked with pale yellow ; but usually they are of a uniform brown." 



Immature. Uniform brownish-black on the upper -surf ace ; the lower, uniform 

 brownish-grey ; the white bases of the primary -quills extensive. 



