178 
ICELAND GULL. 
ceived; the head streaked a httle with grey; the rump 
and vent irregularly barred with pale-brown, and the pri- 
mary and secondary quills dull white ; the bill nearly of 
the same length as that of the Greater Black-backed Gull, 
but more slender, and less hooked. The tail consisted of 
twelve feathers, of a bluish-grey colour, some of which 
were faintly and irregularly barred with dull white. In 
weight, this species is little inferior to the Larus marinus, 
and occasionally it occurs even of a greater size. 
The specimen which I have now the honour of submit- 
ting to the examination of the Society, differs in no import- 
ant respect from the individual above described. Its size 
is rather smaller ; but this was obviously owing, chiefly to 
the unusual leanness of the bird when it was killed, and to 
the subsequent shrinking during its preservation. Its plum- 
age, generally, is darker ; the brown spots and bars occur- 
ring on the wing-coverts, and on some other parts of the 
body, better defined, and the irides dark-brown ; but these 
varieties are at once accounted for, on the supposition of its 
being a younger bird. From this consideration, I have pre- 
ferred giving here the description of the specimen sent to 
London, to that of the present one ; and also from its afford- 
ing a more accurate representation of the general appear- 
ance and size of this bird, as met with in the Zetland 
Islands. 
This species is never known to breed in Zetland. It 
arrives in that country about the middle of autumn, and 
leaves it toward the end of spring; and this migration 
appears to be completely general, at least, I do not re- 
member seeing one during the whole summer season. In 
this respect it totally differs from all those species of known 
Gull, to which, on a superficial view, it might be supposed 
to approximate. 
Its favourite resorts are the entrances of the more expos- 
