CEYLON RAILS, WADERS, GULLS, AND TERNS. 249 
Distribution —Until recently only a few specimens have 
been recorded from Ceylon, but in April, 1914, at Topawewa 
and Minneri in the North-Central Province, and in April, 1915, 
near Hambantota, I found a fair number of specimens flying 
among flocks of the previous species. At that time of year 
the birds were changing to summer dress, and the black wing 
lining at once betrayed them. It is possible that being 
mainly migrants, and almost indistinguishable from the 
Whiskered Tern in their winter dress, they often pass unnoticed. 
The species is common in certain localities in Burma, but 
extremely rare in India west of the Bay of Bengal. It ranges 
through temperate Europe and Asia in summer, wintering 
southwards from, Africa to Australia. 
Habits —Those of the last species, with which it associates. 
As it has been obtained in the Island in May, July, and 
October, it is quite possible that if ever H. hybrida is found 
breeding in Ceylon, this species may be found nesting in the 
same colony. The eggs are very similar, but slightly smaller 
and darker. 
HyYDROPROGNE CASPIA (Blanford, Vol. IV., p. 309). 
STERNA CASPIA (Legge, p. 1008). 
The Caspian Tern. 
Description.—Summer : The forehead, crown, and nape 
are glossy green-black ; remainder of the upper parts and the 
wings pearl-gray ; primaries when fresh are frosted, getting 
darker as the frosting wears off ; rump and tail pale gray ; 
entire under plumage white. 
In winter the black cap becomes white, thickly streaked 
with black, and behind it is a white collar. 
Young birds resemble adults in winter dress, but have more 
black round the eye ; the mantle and tail are mottled and 
barred with rusty black, and the primary quills black frosted 
with gray. 
Bill stout, coral-red ; iris dark brown ; legs and feet black. 
Length 20; wing 15:5; tail 5°5; depth of fork 1:25; 
bill from gape 3°5. 
