396 NATATORES. 



and the two have been sometimes confounded with each 

 other, and also with the brown-headed, which is also nearly 

 of the same size. One of the causes of that confusion is the 

 fading of the dark colour on the heads of all the three species 

 in the winter, and the consequent similarity to each other 

 both at that season, and during the times that the changes 

 both ways are in progress. The different red tint of the bill 

 and feet, and the white on the primary quills of the laughing 

 gull, in all stages of its plumage, whether arising from age or 

 from season, are at once sufficient to distinguish them. The 

 bill and feet of the laughing gull are bright vermilion red, 

 while those of the present species are deep lake red. They 

 are both birds of rather more southern localities than the 

 brown-headed gull, with which both have been sometimes 

 confounded, and the species under consideration seems to be 

 the most southerly of the two. That species is a more 

 seaward as well as a more northerly bird than either this 

 or the laughing gull ; and it has the feet and bill more 

 slender, and approaching nearer in resemblance to those of 

 the terns. 



The present bird is handsome in the outline, and well 

 contrasted in the colours. The crown of the head is very 

 deep lead colour, which appears nearly black from the con- 

 trast with the under parts of the bird. This dark cape 

 extends a little way down the nape, and also the neck in 

 front. The rest of the upper part is also lead colour, but not 

 quite so dark. The quills are deep black : the under part is 

 white, with very delicate rose-coloured reflections, which fade 

 soon after the bird is killed. 



In the winter plumage the forehead becomes white, ex- 

 cepting a few grey feathers at the base of the bill. The 

 whole of the upper plumage becomes olive grey, with the 

 exception of the primary quills, which retain a dark hue. 

 The smaller coverts become brown ; the larger ones acquire 



