596 GAVIA RIDIBUNDA. 



Length to end of tail 16 inches ; extent of wings 38 ; 

 Aving from flexure 17 j ; tail 5 ; bill along the ridge Ij^^ ; 

 along the edge of lower mandible 2 ; tarsus 1-j^ ; hind toe -^, 

 its claw -Jg ; second toe l-ji^j its claw -^; third toe Ij-^, its 

 claw -^i fourth toe 1^, its claw -^. 



Female in Summer. — The female is smaller, but in 

 colour the same. 



Length 15 inches; extent of wings 37; bill l-^; tarsus 

 Ij^Y > third toe ly\-, its claw -^. 



Variations. — There are considerable differences in size ; 

 the tarsus, in particular, varies from an inch and seven- 

 twelfths to an inch and nine-and-a-half-twelfths. The grey 

 tint on the head varies in depth and extent, as does the 

 black on the outer quills. 



Male in Summer. — The bill and feet are of a brighter 

 tint. The colours of the plumage as in winter ; but the lower 

 parts faintly, sometimes strongly tinged with rose-colour, and 

 the head of a sooty-brown, lighter anteriorly, but becoming 

 brownish-black behind ; the space thus coloured ending on 

 the occiput, but on the fore-neck extending to two inches 

 and a half from the base of the lower mandible. Both eye- 

 lids have a band of white feathers, unless at their fore part. 



Female in Summer. — Similar to the male. 



Habits. — The Brown-hooded Mew, commonly but errone- 

 ously named the Black -headed Gull, is generally dispersed 

 along the shores, but is found congregated more especially in 

 estuaries, and near the moutlis of rivers, during the cold 

 season. Its food then consists of small fishes, which it picks 

 up from the surface of the water, as well as of Crustacea, 

 asterise, and marine worms, Avhich it finds on the shores. 

 Frequently, however, it makes excursions inland to search 

 the pastures and ploughed fields for worms and larva?, 

 especially during stormy weather. Both then and at other 

 times it mingles with Gulls, and is frequently seen in com- 



