300 SPOLIA ZEYLANICA. 
Order TUBINARES. 
Family PROCELLARIID #&. 
Petrels. 
The Petrels are oceanic birds, which generally live far 
from land, resting on the water, and resorting to the shore 
merely for breeding purposes. In outward form they are 
not unlike Gulls, but differ from them in many characteris- 
tics of their structure. They may be told apart from all 
other orders by their nostrils, which terminate externally in 
tubes. These tubes may be united or separate, the nostrils 
in some species having but a single orifice, in others a double 
orifice separated by a septum. The upper mandible of the 
bill is deeply grooved, and generally sharply hooked at the 
tip. The front toes are well webbed ; the hind toe or hallux 
is small, often represented by a mere claw, or sometimes absent. 
The wings are long in most forms, and the flight swift and 
powerful, the birds generally skimming near the surface of the 
waves. They feed on small floating forms of marine life and 
on small fish. Many of them follow in the wake of ships and 
feed on the refuse thrown overboard. 
Several different methods of classification have been adopted 
within the order. Blanford, largely for the sake of conven- 
lence, seeing that the birds found in Indian seas are limited to 
rare stragglers of a few species, has left all the Indian genera 
in one family—Procellariide. 
Three species, each representing a genus, have occurred 
within Ceylon limits. 
Rough Key to Ceylon Procellarude. 
A.—Size small ; wing under 7 inches ; nostrils with a single 
external orifice. 
Oceanites oceanicus (Wilson’s Stormy Petrel). 
B.—Size medium ; wing 11 inches; nostril tube with a 
double external orifice separated by a broad septum ; 
plumage dark brown. 
Puffinus chlororhynchus (Green-billed Shearwater). 
