184 British Birds, 



sea, and in dry sites. The Black Tern, however, 

 selects marshy places and often builds in very wet 

 spots, making a nest of flags and grass. The egojs are 

 sometimes four in number, this being the only Tern 

 which lays more than three. They vary much in 

 colour and markings, some being of a palish green, 

 others of a brownish yellow, or dull buff, but all 

 spotted and blotched with deep brown. — Fig, 6, 

 plate XL 



WHITE-WINGED BLACK 'lW^'^—{Hydrochelidon 

 Icucoptera ; formerly, Sterna leucoptera), 

 "A rare straggler." 



WHISKERED "YY.K^^-^^Hydrochelidon hybrida ; 



formerly, Sterna leucopareid). 

 Like the last. 



GULL-BILLED 'YY.V.'^— {Sterna Anglicd). 



Of more frequent occurrence than either of the 

 two last ; and especially in Norfolk. 



CASPIAN TERN— (5/6r;/^ Caspia). 



It may be remarked in connection with the birds 

 we are now among, that the Grebes, Divers, Cormor- 

 ants are all gifted with wonderful powers of diving ; 

 the Gulls and Terns are incapable of diving an inch. 

 The latter, buo^^ant and sitting as lightly on the w^ater 

 as a cork ; the former deep-sunken in the water, and 

 seeming to require almost an effort to support them- 

 selves on the surface at all. The contrast is certainly 



