LARIDZ—GULLS. 291 
Young: Probably undistinguishable from the young of 
L. argentatus, except that the legs are said to be flesh-coloured. 
Distribution: “ Resident in the Mediterranean and Black 
Seas, and ranges eastward through the Caspian and Aral Seas 
to Lake Baikal and the valley of the Amoor ” (Seebohm). 
Habitat : The sea-coast, and inland lakes and rivers. 
SIBERIAN HERRING GULL. 
Larus affinis Reinh. 
Adult (Summer): Resembles Z. fuscus, but has a much 
paler mantle, has a proportionately smaller foot than either Z. 
argentatus or L. cachinnans, but larger than Z. fuscus. From 
the last it may also be distinguished by its larger size and the 
distinct “pattern” of the outer primaries, the grey wedge 
being quite marked on this species, whilst it is absent in the 
outer feather of LZ. fuscus ; bill, legs and feet yellow. Length 
about 20 inches ; culmen 2°75 ; wing 17°4; tail 7; tarsus 2°8. 
Young: “Resembles the young of Larus Juscus, but is 
rather paler and more marked ” (Dresser). 
Distribution : “Breeds in the Arctic regions of Siberia, 
from the White Sea to Behring’s Straits, across which it ranges 
into Alaska, passes through the Caspian on migration, and 
winters in the Arabian Sea ” (Seebohm). 
Habitat: The sea-coast as well as inland waters. 
GREATER BLACK-BACKED GULL. 
Larus marinus Zinn. 
Adult (Summer): Closely resembles Z. Juscus, but may 
be distinguished from that species by its larger size, in having 
a distinct wedge on the third and fourth primaries, and in 
having the degs and feet flesh-colour. Length 30 inches; culmen 
2°75 ; wing 20; tail g; tarsus 3. Female rather smaller. 
Adult (Winter): As in Z. fuscus, the head and neck 
are spotted and striated with brown. 
Young: “The young birds in their stages to maturity 
resemble the young of the Lesser Black-backed and Herring 
Ur2 
