!284 Mr. Montagu's Observations 



but in some so near it as not to admit of a specific mark of di- 

 stinction : the bill and legs dusky. 



In cases of this nature we can only form opinions upon long 

 and continued observations, noted with care and circumspection : 

 upon such observations, therefore, we found our opinion, though 

 it would be difficult to produce more than strong presumptive 

 proof on such a question ; but by pointing out our suspicions, we 

 may stimulate others to join in the pursuit of investigating such 

 abstruse subjects. 



Black-headed Gull. 



Larus ridibundus. Gmel. Syst. p. 601. Ind.Orn.ii. p. 811. 

 Black-headed Gull. Br. Zool. ii. No. 252. Lath. Syn. xi.p. 380. 

 Gull, black-headed. Orn. Dictionary. 



From the very great confusion, which seems to have arisen in 

 some species of the Gull tribe, occasioned by a very considerable 

 variation in plumage at different ages and seasons, we trust it will 

 not be unacceptable to this Society and to the critical ornitholo- 

 gist, if from long and strict attention to several of this genus, 

 which for many years have almost daily been presented to our 

 view, we should endeavour to clear away a little more of that 

 mist which has, for so long a period, veiled in obscurity those 

 birds which are usually known by the names of Black-headed 

 Gull, Larus ridibundus, Red-legged Gull, Larus cinerarius, Brown- 

 headed Gull, Larus erythropus, Brown Tern, Sterna obscura, all of 

 the Gmelinian system; and the Brown Gull of the Second Sup- 

 plement to Latham's General Synopsis. 



It is a claim which science has upon the naturalist — the endea- 

 vour to elucidate any of the more obscure objects of the crea- 

 tion : in our attempt, therefore, to throw light upon a subject 

 \\bich has caused so many various opinions, we beg leave to say, 



that 



