STERCORARIUS PARASITICUS. 303 



Young. Above dark brown; below paler, with buff margins to the 

 feathers ; tail brown, two centre feathers only very slightly longer than 

 the others. Length 21 inches, leg 2. 



351. Stercorarius crepidatus (J. F. Gmelin). Richardson's 



Skua. 



Spanish. Cagalo (Malaga) (Arevalo). 



Favier only mentions one specimen of this Skua, killed near 

 Tangier in 1844. It is, however, not uncommon in winter. "NY as 

 often seen off Malaga in March, 1882. 



Two forms or races are found. 



Dark race. Adult uniform sooty brown, to which the name Richardson's 

 is strictly applied; but the name Arctic, also employed, is a misnomer, as 

 this bird breeds and also migrates further south than any of the other 

 northern Skuas *. 



Light race. Adult nearly as those of next species, but two centre tail- 

 feathers only 3 inches longer than the others. Legs black. 



Young. Sooty brown; paler below; centre tail-feathers little longer than 

 the others. 



All primaries with white shafts. 



Length, including centre tail-feathers, about 20 inches. 



352. Stercorarius parasiticus (Linnseus). The Long- tailed or 



Buffbn's Skua. 



This Skua is recorded by Favier as twice obtained near Tangier 

 in 1846, and in October, 1858, the first being an immature 

 specimen. 



Adult. Crown black; above brownish grey; below white; sides of neck 

 white, tinged with yellow; legs slate-grey. Two central tail-feathers about 

 9 inches longer than the others. 



Young. Sooty brown; flanks and tail-coverts with buff margins; centre 

 tail-feathers little longer than the others. 



First two primaries with white shafts, but it is said that the nostrils of 

 Buffon's Skua are nearer the frontal feathers than the tip of the bill in 

 Richardson's Skua the contrary being the case. 



Length, including central tail-feathers, 22 inches. 



* The writer has observed a light male and a dark female paired together at 

 their nest on one of the Hebrides, where the dark and light forms were about 

 equal in numbers. 



