[Illustration 070: White.] [Illustration: Least Petrel. Stormy Petrel. Forked-tailed Petrel.] [Illustration: deco.] [Illustration: left hand margin.] Page 69 105.2. KÆDING'S PETREL. _Oceanodroma kædingi._ This bird is similar to Leach Petrel, but is smaller and the tail is less deeply forked. Its range is from California to Panama breeding on the Revillagigedo Islands off Mexico. 106. LEACH'S PETREL. _Oceanodroma leucorhoa._ Range.--North Atlantic and North Pacific Oceans, breeding from Maine and from the Farallones, northward to Greenland and the Aleutians. These are the most common of the Petrels found on our coast; they are eight inches in length, of a sooty brown color, and have a white rump. The forked tail will at once distinguish them from any of the Atlantic Petrels. They nest in burrows in the ground, laying a pure white egg, sometimes with a very faint dusty wreath about the larger end. Size 1.20 × .95. These birds generally take turns in the task of incubation, one remaining at sea during the day and returning at night while his mate takes her turn roving the briny deep in search of food. The young are fed by regurgitation upon an oily fluid which has a very offensive odor. This odor is always noticeable about an island inhabited by Petrels and is always retained by the eggs or skins of these birds. They are very rarely seen flying in the vicinity of their nesting island during the day; the bird that is on the nest will remain until removed by hand. Data.--Pumpkin Is., Maine, June 22, 1893. Single egg; nest of a few grasses at the end of a burrow dug in the bank. Collector, J. Lefavour. 106.1 GUADALUPE PETREL. _Oceanodroma macrodactyla._ This species, which is very similar to the preceding, except for a longer and more deeply forked tail, breeds on Guadalupe Is. Their eggs are white very minutely wreathed with reddish brown; they are, however, nearly always nest stained to an uneven brownish color. Data.--Guadalupe Is., Lower California, March 24, 1897. Single egg laid on a few oak leaves and pine needles at the end of a three foot burrow. Size of egg 1.40 × 1.00. Collector, A. W. Anthony. [Illustration 071: White.] [Illustration: Kæding's Petrel. Leach's Petrel. Guadalupe Petrel.] [Illustration: White, nest stained.] [Illustration: right hand border.] Page 70 107. BLACK PETREL. _Oceanodroma melania._ Range.--South Pacific, from southern California southward, breeding on the small islands on both coasts of Lower California. They are similar to the Leach's Petrel except that the rump is blackish. Data.--San Benito Is., Lower California, July 23, 1896. White egg laid on bare ground at the end of three foot burrow. Size 1.40 × 1. Collector, A. W. Anthony. 108. ASHY PETREL. _Oceanodroma homochroa._ Range.--California coast, breeding on the Farallones and Santa Barbara Islands.