252 BIRDS OF MIDDLESEX. 



mouth of the river for the diversion of shooting 

 Gulls, which, at this season of the year, appear in 

 some numbers ; and, when nearly opposite Blackwall, 

 he killed the rare specimen which is now before 

 me. 



Referring to Mr. Thompson's description of the 

 first British example recorded, and which was taken 

 from a young bird shot in Belfast Bay, I find, on 

 comparison, that it will apply to the bird now under 

 consideration, except in a few particulars presently 

 to be mentioned. The description of the Thames 

 bird is as follows : — 



Bill slender and dark brown ; irides hazel ; fore- 

 head, cheeks, throat, and sides of neck white ; crown, 

 nape, back, scapulars and wing-coverts smoke-gray, 

 the tip of each feather margined with dirty white, 

 giving all the upper parts of the plumage a peculiar 

 mottled appearance. Throat, breast and under parts 

 white. Primaries black, with outer half of inner 

 webs white, and the 4th, 5th and 6th tipped with 

 white : secondaries white : upper and under tail- 

 coverts white. Tail-feathers twelve in number, 

 white, with tips black to the extent of an inch from 

 their extremities, giving the appearance of a broad 

 black band when the tail is spread. The two outer 

 tail-feathers the longest, the two centre ones the 

 shortest (an inch shorter) ; the intermediate ones on 

 each side growing shorter as they approach the 

 centre, giving the tail a very forked appearance 



