AND TYPES OF EGGS. 39 
Sternula, Thallasseus, Onochoprion, Anous).—Terns are as a rule migra- 
tory, and congregate in flocks during the breeding season. The 
Caspian tern (S. caspius) does not breed in this country; and the 
eull-billed tern (G. anglicus) only breeds in the far north-west. The 
marsh terns (Hydrochelidon) breed here and there in India gregariously 
on weeds floating in swamps. The true terns (Gelochelidon, Sterna, 
Seena, Sternula) lay their eggs on the bare sand in the beds of large 
rivers. The sea terns (Zhallasseus, Onochoprion, Anous) lay on bare 
rocky islands off the sea-coast. All the terns lay handsomely marked 
eggs. 
Skimmers, (Rhynchops).— Are permanent residents here, and are 
similar in their eggs, habits, and distribution to the true terns (Sterna). 
Fishers, (Phaeton, Sula, Attagen).—Are all sea-birds which are 
found in Indian waters, but which are not known to breed on our coasts. 
Pelicans, (Pelecanus).—Pelicans are widely spread throughout 
India in the cold weather, but of their breeding here nothing is known. 
They are said to build on trees. 
Cormorants, (Graculus).—Are permanent residents in India, 
frequenting rivers and large tanks, They are gregarious and consequently 
local breeders. The breeding of the big cormorant (G. carbo) is not 
accurately known; and this bird is certainly toa great extent migratory. 
The eggs of cormorants are dull chalky white. 
Snake Birds, (Plotus).—Are permanent residents in India, and 
are similar in their habits and eggs to the cormorants. 
