Guu. NATATORES. LARUS. SOLD oe 
In summer the head and neck are pure white; the grey Summer 
streaks disappearing on the approach of spring. pom 
In the young state the ground colour of the plumage is a Young. 
greyish-white, with a slight tinge of wood-brown, barred 
and spotted all over with grey or broccoli-brown. Tail 
irregularly spotted with pale brown. 'The shafts of the 
primaries white, and the whole of the webs greyish- 
white. Bill livid at the base, and the tip blackish- 
brown. Legs and feet pale flesh-coloured red. 
After the second moult the ground of the plumage becomes 
whiter, and the spots and bars decrease in size and hue. 
The next change produces some of the pearl-grey fea- 
thers upon the mantle, and the under plumage and tail 
become white. At the succeeding moult, that is, at the 
age of three years, the bird is matured, and undergoes 
no further change, except the periodical one, upon the 
head and neck. 
ICELAND GULL. 
Larus 1stanpicus, Edmonston. 
PLATE XCVIII. 
Larus islandicus, Edmonston, in Mem. of Wern. Nat. Hist. Soc. 4. 506. 
—Flem. Br. Anim. i. 139. No. 224. 
Larus argentatus, an Arctic var. Sabine, in Trans. Linn. Soc. 12. 546. No. 
20.—Temm. Man. d’Ornith. 2. 764. “ un varieté qui parait propre aux 
contrées polaires.” 
Larus leucopterus, Buonap. Syn. No. 301.—Faun. Amer. Borcal. 2. 418. 
No. 183. 
Larus arcticus, Macgillivray, Trans. Wern. Soc. 5. 268. 
Larus glaucoides, Temm. Man. 
White-winged Silvery Gull, Richardson and Swainson. 
Iceland Gull, Flem. Br. Anim. 1. 139. No. 224. 
In Mr Epmonston’s first notice of the Glaucous Gull, under Periodical 
the name Larus islandicus, a suspicion is started, from the dif. S"*"% 
ference of size existing between individuals of the newly obser- 
ved kind, that there might be two species, having such a rela- 
