XLVIII. 

 STERNA NIGRA, (linn.) 



Black Tern or Car Swallow. 



The Black Tern breeds in considerable numbers in the flat 

 marshy counties of Cambridgeshire and Lincolnshire, and 

 though in other respects so closely allied to the other species 

 of Terns, it differs from them a good deal in its nidification. 

 Whilst all the other species seek the immediate neighbour- 

 hood of the sea, and choose those places which are the most 

 free from moisture, and lay their eggs frequently upon the 

 arid sand, the Black Tern prefers inland marshes and pools of 

 water, laying its eggs upon tufts of rushes and grass, some- 

 times in very wet situations, and barely raised above the sur- 

 face of the water. Its nest is composed of flags and coarse 

 grass ; its eggs are sometimes three, most commonly four, in 

 number, differing likewise in this respect from the other spe- 

 cies, none of which I have ever known to lay more than three. 

 I am indebted to the liberality of J, D. Salmon, Esq., for a 

 large series of the eggs, from which the three figures in the 

 plate are selected, as affording the most opposite varieties ; 

 they were taken by him with many more off Crowland Wash, 

 in Lincolnshire, where immense numbers of the birds an- 

 nually breed towards the end of May or beginning of June. 



