GULL. NATATORES. LARUS. 489 



any of the other species by the whiteness of the middle part 

 of its primary quills. 



PLATE 92. Represents this bird of the natural size, and in 

 the summer or nuptial plumage. 



Head, chin, and throat, dark hair-brown. At the poste- General 

 rior angle of the eye is a spot of white. Eyelids and t ^^ 

 bill deep crimson-red, the latter measuring one inch and Summer 

 two-eighths from the forehead to the tip. Mantle, sea- P luma g e - 

 pulars, and lesser wing-coverts pale pearl-grey. Outer 

 border of the wings, greater coverts, rump, and tail, 

 pure white. First quill-feather having the lower part 

 of the outer web, the tip, and outer margin of the inner 

 web, black ; the rest of it white. The three next quills 

 have the greater part of their outer webs white ; their 

 ends (except the extreme point, which is white) and 

 half their inner webs, black, passing into blackish-grey 

 near the bases of the feathers. The remainder of the 

 quills are pearl-grey, marked with black, as in the pre- 

 ceding. Under plumage white, having, in some speci- 

 mens, a slight rosy tint. Legs and toes deep arterial 

 blood- red. 



In winter, or after casting the hair-brown hood, the head Winter 

 and throat are of a pure white, except a small spot of 

 blackish-grey at the anterior angle of each eye, and an- 

 other of the same colour upon the auriculars. The bill 

 and legs also lose a little of the intensity of hue that 

 distinguishes them in summer. 



The young of the year, previous to the autumnal moult, Young, 

 have the head and occiput of a yellowish-brown, and the 

 auriculars and space behind the eyes white. Lower 

 part of the neck and under plumage white, with a faint 

 blush of pink. Mantle, scapulars, and lesser wing-co- 

 verts broccoli-brown, the feathers being edged with pale 

 yellowish-brown. Lower part of the back, and basal 

 part of the tail, white, with a broad bar of clove-brown 



