248 THE BIRDS OF THE BRITISH ISLES. 



yellow tip. The cap of the mature bird is very black, but in 

 the immature after the moult it is brown, barred and spotted 

 with white ; white streaks and spots appear at times on the 

 foreheads and crowns of adult birds before they leave the 

 ternery, for in winter the top of the head is merely streaked 

 with black. The mantle and tail of young birds have angular 

 black and brown markings. The irides are dark brown. 

 Length, 15 ins. Wing, 13 ins. Tarsus, i'2 ins. 



Sooty Tern. Sterna fuUginosa Gmelin. 



Rather more than half a dozen examples of the Sooty Tern 

 have wandered north from tropical or subtropical seas, and 

 fallen exhausted on our shores or in inland localities ; some 

 were shot, but most have been picked up dead or barely alive. 

 The visits have been in both spring and autumn. The crown, 

 back of the neck, and a streak through the eye of the adult bird 

 are black, the back, wings, and tail — except the outer web of the 

 streamer— are sooty black; the rest of the plumage is white. 

 The bill and legs are black, the irides blackish brown. The 

 young bird has the dark back feathers tipped with white, and 

 the under parts are sooty brown. Length, 16 ins. Wing, 11 75 

 ins. Tarsus, 0*9 in. 



Black Tern, Hydro chelido7i ftigra (Linn.). 



About a hundred years ago the Black Tern or " Carr-Swallow " 

 (Plate in) nested freely in the east coast marshes, but now 

 it is a passage migrant only, halting for food in April and 

 May, August and September. A Black Tern in June or 

 October is unusual, in other months very rare. On passage 

 it is regular and sometimes numerous in eastern counties as 

 far north as Yorkshire, crossing south-eastern England on 

 migration to and from its breeding grounds in Denmark, 



