582 



GAVIA. MEW. 



The Sea-Mews, or smaller Gulls, differ fi-om the birds of 

 the last genus in being inferior in size, of a more slender 

 form, and especially in having the bill and feet compara- 

 tively feeble. 



Bill rather long or of moderate length, slender, much 

 compressed, slightly decurved at the end, acute ; upper man- 

 dible with the dorsal line straight for half its length, then 

 slightly arcuato-declinate, the ridge convex at the base, 

 narrow beyond the nostrils ; the lateral sinus rather long, 

 narrow, and feathered ; the nostrils sub-basal, long, linear, 

 a little wider anteriorly, margined above with a sloping 

 thin-edged membrane, the branches narrow and convex, the 

 edges very thin, inclinate, the sides beyond the nostrils 

 nearly erect and flattened, the tip narrow, rather acute, very 

 slightly prolonged, and with a faint sinus on the margins ; 

 lower mandible very much compressed, with the intercrural 

 space very long and extremely narrow, the crura erect, 

 convex, their lower outline a little concave anteriorly, forming 

 at the commissure a slight angle with the dorsal line, which 

 is nearly straight, the edges very thin and inflected, the tip 

 rather acute ; the gape-hne commencing beneath the eyes, 

 straight, slightly arcuato-declinate at the end. 



Mouth of moderate width ; palate flat, with two very 

 prominent papillate ridges and intervening papillae, ante- 

 riorly with five ridges ; posterior nasal aperture linear. 

 Tongue emarginate and minutely papillate at the base, 

 fleshy, slender, tapering, horny beneath. CEsophagus very 

 wide throughout, its walls extremely thin ; proventricular 

 portion wide, with a continuous narrow belt of very small, 

 oblong glandules, and traversed by very prominent rugae, 

 continuous with those of the stomach, which is rather small. 



