592 LARID^. 



zond, and the Russian naturalists found it in the vicinity 

 of the Caspian Sea. 



In the adult bird in summer the bill is greenish- grey, 

 at the base, towards the point, yellow ; irides dark brown, 

 edges of the eyelids red ; the whole head and neck pure 

 white; the back and all the wing-coverts pearl grey, 

 secondaries and tertials the same, but broadly edged and 

 tipped with white ; primaries black on the outer web, 

 with a small portion of pearl grey at the base of the inner 

 web, the proportion of grey increasing on each primary 

 in succession, the first and second primary with a patch 

 of white on both webs near the end, but the extreme 

 tips of both are black, the third, fourth, fifth, and sixth 

 have white tips, but the first set of primary quill-feathers 

 which the young bird carries for the first fifteen months, 

 have no white at the tips. Few birds moult their first 

 set of quill-feathers in their first autumn. Tail- coverts 

 and tail-feathers pure white ; chin, neck in front, breast, 

 and all the under surface of the body and tail pure white ; 

 legs and feet dark greenish-ash. The whole length of an 

 old male is eighteen inches and a half ; of the wing from 

 the point fourteen inches and a half. The length of an 

 old female is about one inch less, and of the wing half an 

 inch less. 



In the winter the whole head and the sides of the 

 neck are streaked and spotted with dusky brown and ash 

 brown. 



A young bird in its first autumn has the basal portion 

 of the bill yellowish -brown, the part anterior to the nostrils 

 nearly black ; irides dusky ; head, sides of the neck, the 

 ear- coverts, and occiput dull white, mottled with greyish- 

 brown; the back, wing-coverts, secondaries, and tertials 

 brownish-ash, the feathers edged with paler brown ; a few 

 bluish-grey feathers on the centre and sides of the back ; 



