OCEANODROMA.
Tarsus less than middle toe with claw ; tail forked.
Oceanodroma leucorrhoa leucorrhoa (Vieillot). LEACH'S FORK-TAILED PETREL.
? Sooty brown, tinged above with slate, lateral upper tail coverts white, some with grey tips. Bill, legs and feet black. Wing 153-161. Tarsus 24-26. Bill 14-15.
Breeds.—Iceland (Westmann Islands), Hebrides and Isles of Mayo and Kerry ; also east coast N. America northwards from Maine and in N. Pacific on Aleutian, Kurile and Copper Islands. \Vanders to other seas ; occasionally visits Coasts of Baltic and North Seas, France, Spain, Portugal and W. Mediterranean ; also W. African Coast south to Sierra Leone and Liberia ; Azores, Canaries, and Madeira. Has been reported from St l'aul's Rocks in Mid Atlantic near the Equator and on the American Coast south to Cape San Roque in Brazil, and in Pacific from N. Japan.
Oceanodroma castro (Harcourt). MADEIRAN PORK TAILED PETREL.
Smaller than " leucorrhoa," blacker ; tail less forked, white at base ; upper tail coverts white with black tips. d 150 ,62, 9 147-159. Tarsus 2 1 -23.5. Bill 13.5-16 (\V.).
Breeds.—Desertas and Porto Santo (Madeira group), Salvage Islands, Azores (Rombos), Cape de Verde Islands and St Helena, also in Pacific. Rare visitor to Coasts of Britain, France, Canary Islands, and coasts of N. America. Birds breeding in Hawaiian Islands and Galapagos Islands have been separated as distinct subspecies, but their status is still doubtful.