390 CLASS XVI. 



coloured as Sterna kirundo, but much larger and with black legs, is 

 Sterna caspia PALL., NADM. Taf. 748, seldom observed with us ; its nests 

 cover the dunes on the island Sylt (see a drawing in NAUMANN Ueber den 

 Haushalt der nordischen Seevogel. Leipzig, 1824, Tab. n). Other species 

 are dark grey, and have in the summer plumage a black breast, Sterna 

 nigra L., NAUM. Taf. 256. These birds live together in flocks on the 

 sea-coast, and lay mostly two or three brown and black spotted eggs. 

 This genus comprises very many species from all parts of the world. 



Larus L. Bill moderate, compressed, cultrate; upper mandible 

 with tip subhooked, lower, with angle below the tip somewhat 

 prominent. Wings elongate, pointed. Tarsi scutellate anteriorly, 

 rather robust. Feet palmate; hallux short, raised, sometimes none. 

 Tail moderate. 



Mews, Gulls. These birds live mostly on fishes, molluscs and insects, 

 some on carrion also ; they fly long and take their prey out of the water 

 while flying with their strong bill ; there are also species which attack and 

 rob other sea-birds of their prey. 



La/rus ILLIG. Nostrils placed in the middle of bill. 



a) Tail forked. Sp. Larus Sabinii, Linn. Transact, xii. PI. 29 ; Green- 

 land. (Sub-genus Xema LEACH, GRAY, related to the Sterns.) 



b) With tail even. Sp. Larus ridibundus L., BUFF. PI. enl. 969, 970, 

 NAUM. Taf. 260; the black-headed Gull; white, light bluish gray above, 

 like most of the species ; legs red ; head and throat in the summer plumage 



, brownish black. Larus argentatus BRUENNICH, GM., BUFF. PI. 253 (the 

 hallux is faultily absent in this, otherwise correct, figure), LESSON Ornith. 

 PL 112, fig. 2; the great sea-mew, silver-mew, herring-gull; very numerous 

 on the islands along the north coast of Holland, where their eggs cover 

 whole districts ; from these gulls' eggs the northern part of Texel has 

 obtained the name of Eijerland. Larus tridactylus L., BUFF. PI. enl. 387, 

 NAUMANN, Taf. 262, &c. 



These birds moult twice in the year. The males are larger than the 

 females, but with the same colours. The young birds are mostly grey, 

 with black or brown spots, and have sometimes been named as different 

 species; thus Larus ncevius L. is the young bird of Larus marinus L. 

 This genus also, although not so large as Sterna, counts many species. 



Lestris ILLIG., Stercorarius BRISS. Bill covered with a cere 

 beyond the middle. Nostrils placed at the extremity of bill. Two 

 middle tail-feathers often elongate. 



Sp. Larus parasiticus L., BUFF. PI. enl. 762, NAUM. Taf. 272, 273 (younger 

 Larus crepidatus GM., BUFF. PL enl. 991, not Lestris crepidata BBEHM, 

 Lestris Buffonii BOIE), LESSON Ornith. PI. in, fig. 2, NAUM. Taf. 272, 

 273, &c. These mews of prey are very ravenous and courageous, and attack 



