662 HYDROCHELIDON LEUCOPTERA. 



In the Annals of Natural History, vol. XV. p. 271, Mr. 

 Frederick M'Coy has given an account of a specimen shot by 

 J. Hill, Esq., on the Shannon, in 1841, in company with the 

 Black Tern, with -which it was confounded. The specimen, 

 which is preserved in the Museum of the Natural History 

 Society of Dublin, is thus described : — 



" Measurement. — Total length to extremity of tail about 

 eight inches ; bill from base ten lines and a half, from rictus 

 one inch five lines ; greatest depth of both mandibles two 

 lines and a half; middle toe, including the claw, eleven lines 

 in length ; tarsus eight lines ; naked portion of the tibia four 

 lines. 



" Colours. — Legs and feet in the preserved specimen pale 

 yellow, probably red in the living bird, claws darker ; bill 

 dark blackish-brown ; head, neck, breast, abdomen, under 

 wing-coverts, and back deep glossy black ; small wing- 

 coverts, tail, and upper and under tail-coverts pure white ; 

 first three quill-feathers black, with a broad longitudinal 

 band of white on the inner webs ; remainder of the wings 

 ash-grey, becoming darker towards the body. 



" The form, proportions, and size of this species are very 

 nearly those of the Black Tern, Sterna nigra. Like that 

 species, too, the webs of the toes are very deeply indented, 

 being reduced to a mere rudiment between the middle and 

 inner toes. The two species are, hoAvever, easily distinguished. 

 The under wing-coverts of the S. nigra are white, of the 

 S. leucoptera black ; the tail of the former is dark grey, of 

 the latter pure white ; in the S. nigra the throat is white, 

 breast and abdomen dark grey, and the back lead-colour ; 

 while in the S. leucoptera all those parts are black." 



