6. STERNA. 73 



Adult in hreeding-plumcifje. Forehead, upper lores, crown, and 

 nape black, neck white, mantle pale pearl-grey ; the primaries a 

 little darker, the inner margins of their webs with conspicuous 

 white borders, which extend to the extreme tips, and even slightly 

 ascend the outer webs, the outer webs and the lines parallel to the 

 inside of the white shafts black to grey, according to the amount of 

 frosting ; rump and tail-feathers very pale grey to white, the outer 

 webs of the long streamers quite white ; underparts white, with a 

 beautiful pink tinge, which is very evanescent : bill orange at tlie 

 base, the anterior part from the angle black ; tarsi and toes 

 orange-red. By tho end of May (in the northern hemisphere) the 

 amount of black on the bill has largely increased. Total length 

 15*5 inches, culmen 1-9, wing 9-25, tail 7"5 to 8, depth of fork 

 about 5, tarsus 0-85, middle toe and claw 1. The tail-streamers 

 are probably a trifle longer in the male ; otherwise the sexes are 

 alike in plumage. 



Adult in winter. Similar to the above, but with the forehead 

 spotted with white, the underparts nearly white, with little pink 

 tint; bill nearly black. 



Immature. Like the above, with a brownish tinge in the black 

 of the head and nape, a dark grey band along the upper wing- 

 coverts ; dark grey centres to the inner secondaries ; moi'e grey in 

 the primaries, with less pronounced white inner margins ; some 

 grey in the outer webs of the tail-feathers, except those of the 

 streamers, which are always white. 



Young. Like the above, with the addition of ash-brown mottlings 

 and striations on the upper parts. When the bird is just fledged, the 

 markings are arrow-headed in shape, and the upper parts are tinged 

 with a warm buff. 



North-American birds are on average a trifle larger than Eastern 

 examples. 



This is essentially a Sea-Tern, usually depositing its eggs on low 

 islands, though sometimes on sand)' coasts. On migration, it 

 occasionally visits large inland sheets of water, such as Lake Leman. 

 It remains in the northern part of its range for a very short time, 

 being the last of the Terns to arrive and the first to leave. 



Hah. Coasts of Atlantic and (sparingly) North Sea, from .57° N. 

 lat. in summer to the ileditorranean, Azores, and Madeira ; North- 

 west, South-east, and East Africa ; Mascarene Islands ; Ceylon ; Sea 

 and Bay of Bengal, Andaman Islands (breeding) ; Tenassorim, 

 Malayasia ; China seas up to Loo-choo Islands ; Moluccas, Australia 

 (except the south), and New Caledonia (breeding). In North 

 America, the east side from Massachusetts southwards to Venezuela, 

 and the West Indian Islands (breeding). 



a. Ad. sk. Firth of Ch'de (type of species). Col. Montagu [P.]. 



b. d ad. sk. ; Fame Is.," Northumberland, R. W. Chase, Esq. [P.]. 

 c, d. Ad. St. Aug. 



e. Ad. St. Scilly Islands. Jas. Griffin, Esq. [P.]. 



