148 BIEDS. 



trils developed; no gular pouch. Wings very long and 

 pointed. Tail well developed; altricial; powers of flight 

 remarkable; food chiefly fishes. There are two families, 

 LaridcB) below described, and Procellaridce, the Petrels, 

 which we here omit, all our numerous representatives 

 being strictly maritime. 



FAMILY LXIIL LARID^E. 



(The Gulls.) 



Long -winged birds, with the nostrils not tubular; 

 bill various. Hind toe small and elevated, but less so 

 than in the Petrels. General color usually white, with 

 a darker mantle of a pearly bluish tint, and commonly 

 with some black markings. Sexes alike in color, but the 

 plumage varying much with age and season. Genera 

 about twelve (Coues), sixty (European authors); species 

 ninety; abounding about all large bodies of water. Of 

 the genera admitted below, Pagophila, Rissa, and 

 Chroecocephahis may properly be considered as sections 

 of Larus, while Gelochelidon and Thalassew are perhaps 

 sub -genera under Sterna. 



* Bill hooked (epignathous) rarely not hooked, and the tail even. 



f Bill with a sort of cere ; middle tail feathers exserted ; Jaegers. 



(LESTKIDIN.E.) .... STERCORARIUS, 1. 



f f Bill not cered ; general color usually white with a darker 



mantle. Gulls. (LARIN^E.) 



a. Hind toe rudimentary, without a developed claw. RISSA, 3. 

 aa. Hind toe perfect, provided with a claw. 

 6. Tail even. 

 c. Tarsus black, rough ; webs incised ; plumage white. 



PAGOPHILA, 4. 



cc. Tarsus not black ; lower plumage white in adult. 

 d. Head white if dark below, head not whitish (spe- 

 cies of large size ; never rosy-tinted below ; the 

 head never with a dark hood.) . LAKUS, 2. 



