642 CASPIAN TERN. 
July oth 1875. To the waters of France, Switzerland, and the 
interior of the Continent, this Tern is only a straggler ; but it breeds 
on the eastern shores of Spain, as well as on some islets near 
Sardinia, and is generally distributed throughout the Mediterranean ; 
it also nests by the Black and Caspian Seas, from the latter of which 
it was first recorded by Pallas. It arrives at the northern limit of 
its range in spring, and departs for the south in autumn ; but is 
resident on the northern littoral of Africa, and along both sidés of 
that continent, as far as Cape Colony. In Asia it ranges from the 
Caspian to China, crossing the lofty mountains on its migrations 
to India and Burma in winter; while it breeds on the shores of 
the Persian Gulf, as well as in Ceylon. In Australia and New 
Zealand it is resident. In America this hardy species is found from 
Labrador to the Yukon, breeding as far north as the Great Slave 
Lake and a little beyond the Arctic circle ; while southward it can 
be traced to both sides of Mexico. 
The Caspian Tern lays in May or June on the bare sand, in a 
slight hollow which is occasionally lined with pieces of shell or a 
few bents ; the eggs are 2-3 in number, and in colour stone-buff, 
spotted and scrolled with ash-grey and dark brown : measurements 
2°s by 1'7 in. The ordinary food consists of fish, The note 
is a loud, harsh krdhke-kra, uttered freely by the bird when its 
breeding-haunts are invaded. This species is nearly as partial to 
brackish lakes as to the sea-shore, and when searching for food it 
has a habit of keeping its bill pointed downwards, almost at a right 
angle to its body. 
The adult in summer-plumage has the bill vermilion-red; crown 
and nape glossy greenish-black ; neck and under-parts pure white ; 
mantle pale french-grey, darker at the tips of the primaries, 
on which the frosting quickly wears off; tail white with a greyish 
tinge, and only slightly forked ; legs and feet black. Average length 
20 in. (bill 3°3), wing 16°5 in.; the male being larger than the 
female and having a stronger bill, though there is considerable 
individual variation, irrespective of locality. In winter the crown is 
streaked with black, and there is a dark patch behind the ear-coverts. 
The young bird has the forehead and crown white ; upper surface 
mottled with ash-brown ; quills ash-grey ; bill reddish horn-colour. 
In the Caspian Tern the tail is very short, less than’ one-third the 
length of the wing ; while the bill is exceptionally stout and deep. 
For these reasons Kaup made this species the type of the genus 
Hydroprogne, which I have adopted (Cat. B. Brit. Mus. xxv., p. 4), 
but its acceptance in this work is not pressed. 
