NATATORES. 263 



difficult to imitate, is worthy of attention, since it 

 helps us to determine the species at a distance, and 

 this is the more important in the case of immature 

 birds. The ordinary note of the Herring Gull is a 

 hoarse laugh or cackle, of five syllables, so to speak, 

 and sounding like " iva-a-a-a-agh^' quickly uttered. 



Great Blackbacked Gull, Larus marinus. This 

 Gull may often be seen towards the mouth of the 

 Thames, and used formerly to breed there, in the 

 marshes on the flat shores of Kent and Essex. 

 Occasionally individuals stray up the river to a 

 considerable distance. I have heard of one which 

 was killed as high up as Putney during a frost. Mr. 

 Bond shot an old bird of this species manj^ years ago 

 at Kingsbury Reservoir. On the 7th March, 1862, 

 I saw a large grey Gull at this sheet of water, which 

 I took to be an immature specimen of the Great 

 Blackbacked Gull : it had probabl}^ been driven 

 inland by the east wind of the previous day. On 

 looking to my note-book for 1864, also, I find an 

 entry to the effect that, on the 5th January, in that 

 year, two large grey Gulls, probably of this species, 

 were seen at Kingsbury. The cry of this bird 

 sounds like " ke-dw, ke-div.'' 



In September, 1868, I brought home a live Great 

 Blackbacked Gull which had been slightly winged. It 

 was a bird of the 3''ear, in the mottled plumage pecu- 

 liar to all young Gulls. As it is still alive (May, 1866) 

 and in good health, I have had an opportunity of 



