LARID.T:. ALCIDiE. 59 



Darlc race. Adult uniform sooty browu, to which the name EicJmrd- 

 sons 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. 



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

 feathers only 3 inches longer tliau 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. 



349. LoyG-TAlLED or Buffon's Skua. Stercorarius parasiticus Arctic to 

 (Linnaeus). Irregularly, autumn to spring. 40°N. in 



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 featliers than the tip of the bill — 

 in Kichardson's Skua the contrary being the case. 



Length, including central tail-feathers, 22| inches. 



Order PYGOPODES. Family ALCID^. 



Great Auk. Alca imjoennis, Linnceus. Extinct : last British 

 sjjecimen, 1834 ; last foreign record, 1844. 



350. Razorbill. Alca iorda, Linnaeus. Resident. 



Bill black, straight, large, much decurved towards point, with curved 

 white line across centre on each side ; upper mandible hooked, with 

 three grooves across. 



In summer. Above black, with green gloss ; secondaries tipped with 

 ■white, forming a band ; narrow white streak from base of upper mandi- 

 ble to eye ; below white, but chin and throat blackish. 



In ivinter. Green gloss above nearly absent ; chin, throat, and sides 

 of head white ; in young birds bill less developed. Length 17 inches, 



35L Common Guillemot, Uria troile (Linna>us). Resident. 



Bill blackish, straight and pointed. 



In summer. Head, neclv, and upper surface dark brown ; below white. 



In ivinter. Throat and sides of head white. Length 18 inches. 



The Ringed Guillemot is a race or variety, with a white ring round 

 the eve and a white line running backwards therefrom. 



