290 SPOLIA ZEYLANICA. 
is long and sharply hooked at the tip ; the upper mandible is 
flattened; the nostrils are situated near the base of the bill; 
the nasal grooves are well marked, and run to the nail at the 
tip. The chin is naked and pouched, the tarsus very short 
and feathered, the web between the toes deeply scalloped and 
the tail deeply forked. The birds obtain their food while on 
the wing, largely, like the Skuas, by chasing Gulls and other 
sea birds and forcing them to drop their catch, but also by 
capturing flying fish or by swooping down on such fish, 
crustaceans, and young turtles as show themselves on the 
surface of the water. The various species range over the 
tropical seas and breed on oceanic islands, constructing a stick 
nest resting on rocks or in bushes. They lay one or two pure 
white eggs. Two species have occurred as stragglers on the 
shores of Ceylon. 
Key to Ceylon Fregatide. 
A.—Bill from gape 4°5 or over ; wing 22 or over. 
Fregata aquila (Man-of-war Bird). 
B.—Bill from gape under 4 ; wing about 20. 
Fregata ariel (Smaller Frigate Bird). 
FREGATA AQUILA (Blanford, Vol. IV., p. 338 ; Legge, p. 1204). 
Frigate Bird ; Man-of-war Bird. 
Description.—Male : black all over ; the head, neck, scapu- 
lars, and back glossed with green and purple. 
Female: back brownish-black; feathers of lesser and 
medium wing coverts lighter brown with a dark shaft stripe 
and pale edges ; breast and sides of abdomen white. 
Immature birds resemble the female, but have the head, 
neck, breast, and middle of the abdomen white ; the flanks 
are darkish brown. 
Bill bluish-gray ; iris dark brown ; naked skin of throat red ; 
legs and feet red. 
Length about 40; wing 22 to 25; tail 15 to 19; depth of 
fork 10 to 11°5; tarsus +08; bill from gape 4°5 to 5°5. 
Females are rather smaller than males. 
Distribution.—The British Museum series includes one skin, 
that of a moulting bird, from Ceylon. The species ranges all 
round the seas of the tropics. 
a 
