v LARIDAE 309 
but all have red bill and feet. The colonies of our marsh- 
breeding species supply large quantities of eggs for eating. 
Of the black-hooded, grey-mantled forms, which have as a 
rule red bill and feet, Z. atricilla, the Laughing Gull, of the 
Atlantic coast of North America and Western Mexico, alone has 
black outer primaries; this species and LZ. franklini, of the in- 
terior of sub-Arctic America, having exceptionally dark mantles, 
and the latter pinkish under parts. Both migrate south in winter. 
Fic. 62.—Great Black-headed Gull. Larus ichthyaétus. ™ 7%. 
L. philadelphia, Bonaparte’s Gull, of all North America, which, like 
its two following congeners, strays to Britain, has the bill black ; 
L. melanocephalus, of the Mediterranean and Black Seas, has a jet 
black head, a partly red bill, and nearly white quills; the very large 
L. ichthyattus ranging from the Black Sea and the Levant to Tibet, 
and wintering in Southern Asia, has the bill almost orange. JL. 
saundersi, a slender-legged stout-billed bird, inhabits the rivers 
and coasts of China and Mongolia; Z. serranus of the Andes 
from Ecuador to Chili being a near ally. L. minutus, the Little 
Gull, frequenting marshy districts in sub-Arctic and temperate 
