GULL. 



131 



GENUS CIV— GULL. 



* Nostri/s distinct. 



1 Great Gull 



2 Black-headed 

 A Red-legged 



B Brown-headed 

 C Brown 



3 Laughing 



4 Georgian 



5 Masked 



6 Little 



A Brown Tern 



7 Forked-tailed 



8 Adriatic 



9 Italian 



10 Crimson-billed 



11 Black-backed 



12 Iceland 



13 Glaucous 



14 Herring 



15 Silvery 

 A Var. 



16 Common 



17 Ivory 



18 Hudsonian 



19 Black-tailed 



20 Kittiwake 



Tarrock, Young 

 A Var. 



21 Pulo Condore 



* * Nostrils covered with 

 a Cere. 



22 Skua 



23 Pomarine 



24 Arctic 



25 Black-toed 



26 Keeask 



27 Pacific 

 A Var. 



JjILL strong, straight, bending at the point; on the under part 

 of the lower mandible an angular prominence. 



Nostrils oblong, pervious, in the middle of the bill, in some 

 covered with a cere. 



Tongue a little cloven. 



Legs small, naked above the knees; back toe small. 



Between the Gulls and Terns there seems to be much affinitv ; 

 and by some authors, they have been considered as one family ; but 

 they are perfectly distinguishable, and easily separated into two 

 genera. The Gulls are in general stouter in proportion than the 

 Terns ; the bills much stronger ; and in some crooked at the end, 

 in a degree equal to many birds of prey ; while that of the Tern is 

 for the most part straight and slender ; the legs are likewise much 

 weaker than in the Gull, and the tail forked at the end* — a circum- 

 stance rarely observed in the last Genus. Great variety, however, 

 is found in respect to plumage in both, arising from the different 

 stages of life, and has occasioned authors to consider many birds a 



* Great latitude should be given in respect to the young of the Tern ; as in some species 

 the tail, during that stage of life, is nearly even at the end. 



S 2 



