41 G LARID.E. 



reddish-brown ; the whole length of the bird nine inches and 

 three-quarters ; the tail less forked than in some other spe- 

 cies ; the wing from the carpal joint to the end of the first 

 quill-fcather eight inches and a half. 



Adult birds in winter have the forehead, the space between 

 the beak and the eye, the chin, and throat white, and I have 

 seen an adult female specimen that had assumed this white 

 colour before leaving this country in autumn. The other 

 parts as in summer. 



Young birds of the year have the bill brownish-black ; 

 forehead, chin, throat, and a collar round the neck white ; 

 crown of the head and the nape greyish-black ; feathers of the 

 back and wing-coverts light slate-grey, margined with brown 

 or white, or partly with both ; primaries dark slate-grey ; the 

 first primary lead-grey ; rump and uj^per tail- coverts greyish- 

 Avhite ; tail-feathers slate-grey ; breast, belly, and all the 

 under surface of the body and wings white. Before leaving 

 this country the plumage on the upper surface of the body in 

 the young bird loses the brown colour, becoming of a more 

 uniform slate-grey, but clouded with dark lead-grey. This 

 Tern having once assumed the dark colour peculiar to the 

 breast and belly in summer, does not afterwards become white 

 on those parts at any age or season. 



