338 laridte. 



black band of immaturity of equal breadth across tlie tail, one had the head black, 

 and the other white. April \1th. I examined through a telescope, though they 

 were not far distant, a number of these gulls. They differed much iu plumage, 

 some having the fi'ont of the head black, others greyish-brown, but all, in either 

 state, having the back or hinder part of head pure white, b'ke L. cainstratus ; more 

 than were iu either of those states had the head faintly mottled with grey and white : 

 most of the birds in this plumage had a black band across the extremity of the tail. 

 May %rd. I examined most particularly, this evening for half an hour, with a tele- 

 scope, a flock of aboirt a hundred when feeding on the ooze of the river Lagan, close 

 by the Botanic Garden. Some had the front of the head black, like those on the 

 17th of April ; others, brown ; the back or hinder part of it being white in 

 all displaying this " masked " appearance. — Some of those having brown in front of 

 the head, had a round white marking extending from the upper mandible. Some 

 had the head mottled, and others pure white, excepting the black ear- and eye-spots 

 (^. e., were in winter plumage) . The legs of those nearest me (about sixty yards off), 

 which happened to be the most adidt, were bright lake-red. June V^th. The only 

 bird of a small flock of six that came near me displayed the black baud of immatmity 

 on the tail. 



1839. March 1\st. I was much struck with the beauty of some of these birds 

 which were feeding very near me at the edge of the bay, and had not yet as- 

 smncd the entire black head, the hinder half only being of this colour, and the an- 

 terior pure white, which appears to me more elegant than the entire black head. I 

 have shot arctic terns in June, at theii* breeding-haunts, with the anterior portion 

 of the head thus white. 



1842. Marcli 'i^th. 1 observed several of the L. ridihundus, vrith heads black as 

 iu summer, but a few which I saw iu the bay, on the 12th of May, had not black 

 heads, but, instead, a mere extension of the black ear-spot which we see in winter : 

 this was simply extended a little on either side, terminating in a point, so as instead 

 of a round spot to appear a narrow crescent of black. 



1843. March Ylth. Great numbers of these birds in the river Lagan, displaying 

 black heads. 



1845. May &th and 1th. Of about a hundi'cd and twenty seen each day in the 

 Lagan, near the Botanic Garden, not more than one-fourth had the heads black. 

 May \^th. Of a similar number examined at same place thi'ough a telescope, some 

 were in adult L. ridibundus plumage, in hood-like form of black on head, the black 

 in such birds being of a greatly deejjer shade of colour than in other individuals 

 which were but masked. Some birds had no black on head but eye-spot, and had a 

 l)road band of black on tail. 



Roseate plumage. — I have had communications from various parts of Ireland, iu- 

 cluding the south, respecting rosy gulls, and specimens have occasionally been seut for 

 my examination. They were all of this species, differing only from onUnary birds iu 

 being of a rich cream-coloured roseate hue where others are white ; and most con- 

 spicuously so on the breast. Eew birds from any part of the woi'ld present a more 

 elegant appearance. The descriptiou of one will suffice. 



Octolter ihik, 1832. The most l)eautiful specimen of X. ricllljuiidas that I have 



