vo LARIDAE 303 
remainder of the tribe generally collect a mass of grass, moss, 
flags, sedges, heather, twigs, or sea-weed, though a mere hollow in 
the soil or sand often serves their purpose. The eggs vary in 
number from two in the case of the Ivory Gull and the Skuas to 
three or exceptionally four; they are brown, drab, or green, with 
blotches and spots of brown, black, grey, and lilac, and recall those 
of Plovers. Both sexes have been said to incubate in Larus minutus 
and Rissa brevirostris ; the young are comparatively helpless for a 
few hours or perhaps days, and are at first fed by the parents. 
Terns resemble Gulls in many of their habits, but are more 
cosmopolitan, and decidedly migratory in Britain; they are 
essentially marine, yet some species breed on inland waters in 
summer. Particularly slender and graceful, these long-winged birds 
may usually be distinguished by their irregular or hovering flight, 
and are known as Sea-swallows; while their method of beating 
up and down maritime streams or shallows, singly or in pairs, 
in search of fish, is quite peculiar to themselves. At such times 
they make constant plunges into the water, often completely 
immersing their bodies, or occasionally discontinue their opera- 
tions to engage in trivial and seemingly amicable quarrels. The 
note, though hoarse in some cases, is usually a squealing or 
erating sound, the latter especially when disturbed ; the food con- 
sists of fish and crustaceans, insects—said to be sometimes taken on 
the wing—frogs, newts, locusts, grasshoppers, caterpillars, leeches, 
molluscs, and medusae. Terns are wary but bold, commonly 
circling around a wounded companion until several are shot; the 
Noddies (Anous), however, are much more sluggish and silent. On 
the ground all move with comparative ease. The nest of Hyd7o- 
chelidon 1s a mass of water-weeds placed on some tussock in a wet 
inland swamp; that of Anous, whem situated on trees, bushes, or 
rocky ledges, is composed of twigs, sea-weed, and like materials ; 
but most species merely make a hole in the sand or soil, with little 
or no lining. Depressions on level rocks, the surface of prostrate 
plants, and heathery, grassy, or muddy flats are often utilized as 
alternatives, while colonies are usually formed. Two or three olive, 
reddish-brown, green, or stone-coloured eggs, with blotches, spots, 
scrawls,oroblique streaksof black, brown, grey, or lilac,are deposited; 
the Noddy and Sooty Terns, however, have a single white egg with 
red markings, and Gygis one, which is buff, marbled, spotted, or 
often scrolled with brown and grey,and is laid on anyslight cavity of 
