( 999) %) 
size it is about 20 inches ; plumage alters considerably, in winter the 
head is white, with black streaks onthe occiput (back of the head). In 
summer, head, nape and ear-coverts are black? wings, mantle and 
tail, a fine bluish grey ; a few of the primaries are dark tipped and 
edged ; rest of the plumage is white, chiefly back of the neck, and 
under parts of the body ; irides brown ; feet black. 
RIVER TERNS 
Differ, from the previous group in colour, structure and _ habits. 
They have a much longer, and more forked tail ; the body slender. 
They remind us, a little of Hill Fork-tails, in a general sort of way, 
though they have, but little power over their hind appendage. 
These birds live chiefly near rivers, as a rule solitary in their habits, 
occasionally a few are seen together. Bill is deep yellow in colour, 
excepting European Tern, which has a red bill ; legs red, excepting 
the Little Turn, whose legs are orange. Bill in most of the species, 
is long and slender ; feet short and partially webbed. 
(985) SEENA AURANTIA, Large River Tern, is perhaps the 
commonest of this class of Terns in the plains. None of these birds 
however visit the district. It is about 15 inches in length ; bill 
yellow ; irides brown; legs red; plumage, above, is pale grey ; 
tail white; head, above, glossy black; beneath, the body white, 
flanks have an ashy tinge. These birds remain in the plains 
throughout the year, and nest in company, with Skimmers, Small 
Swallow Plovers, and Great Stone Plovers, on the sandy churs of 
rivers. During the day eggs are left to hatch by aid of the hot 
sand and sunshine. These Terns set up a vigorous defence, when 
Crows and Kites venture to rob their eggs. Doubtless, the other 
species of Water-birds seek their company at the breeding season, 
more particularly, owing to their prowess, in driving away 
marauders. 
SEA TERNS 
Have a much more powerful flight, than the latter Terns. They 
frequent deltas of large rivers in the plains, also congregate on the 
sea shores. Their shape is elegent, and lengthened in form ; feet 
are black ; bills yellow. 
GENus THALASSEUS, have webbed feet ; very long wings, which 
extend to tip of the forked tail ; head crested. 
(989) THALASSEUS CRIsTATUS, Large Sea Tern, you are more 
likely to meet, than smaller Sea Tern, which locates itself more in 
