212 PATAGONIAN EXPEDITIONS: ZOOLOGY. 



Gavia roseiventris, Gould, P. Z. S. 1859, p. 97 (Falkland Islands, 



breeding). 

 Larus roseiventris, Scl. P. Z. S. 1860, p. 391 (Falkland Islands); Abbott, 



Ibis, 1 86 1, p. 1 66 (loc. cit). 



GENERAL DESCRIPTION. 



Size. Adult male (breeding). Total length, about 14 inches. 



Wing, 1 1 inches. 



Tail, 4.8 inches. 



Culmen, 1.7 inches. 



Tarsus, 1.75 inches. 



Color. Adult (breeding). General color. Above pale cold grey; 

 with a deep brown hood, below, except the region covered by the hood, 

 white. 



Head: With a deep brown hood, darkest on the nape and throat; 

 a white circle about the eye, broken in front. 



Neck : White, except the portion over which the hood extends. 



Back : Mantle pale cold grey ; this color shading into white or almost 

 white on the rump and upper tail coverts. 



Wing : Upper coverts pale cold grey. The primaries without subter- 

 minal bars. (This characteristic and the smaller size readily distinguish 

 L. glaucodes from L. maculipennis in the breeding plumage.) First pri- 

 mary, with a pure white tip extending down for about two and a half 

 inches. Below this both webs are black reaching to the white shaft. 

 Second and third primaries, with white tips, white outer webs extending 

 well down on the feathers, and with the inner webs chiefly greyish black, 

 but separated from the shafts by a conspicuous white region. The second- 

 aries are like the mantle but paler at their tips. 



Tail: White. 



Lower parts : White, except the throat and chin which are covered by 

 the hood. The breast and abdomen with a deep rose blush tint which 

 generally disappears in dried skins. 



Bill : Crimson. Tarsi : Dull red. Feet : Toes dull red, the webs a 

 little lighter. Iris : Dark hazel brown. 



Adults in winter, lack the hood for a brief period, and the rosy tinge is 

 faint if not absent. Otherwise similar to adults breeding in plumage. 



