490 LEACH'S PETREL. 



and spot on top of head, dark-brown. Remainder of plumage, white. Bill, black, iris, brown, feet, pinkish. Youny, sim- 

 ilar, but with white of head more extended. 



OBSERVATIONS. 



Known by the wliite head and dark crown. Occurs off the Atlantic Coast from New York, southward. Dimensions; 

 length, 16-00; stretch, 39'00; wing, 12 00; tail, 5'45; bill, 1'50; tarsus, 1'50. 



HABITS. 



The Black-capped Fulmar inhabits the Southern Atlantic but does not appear to be 

 very common, though specimens are occasionally taken off the coast. Its habits are simi- 

 lar to those of the preceding species. 



GENUS II. TilALASSIDROMA. THE STORMY PETRELS. 



GEN. CH. Bill, not stout but short. Tail, forked. Members of this genus are small in size and rather dark in color. 

 Legs, long with feet as in preceding. We have three species within our limits. 



THALASSIDROMA LEUCORRHOA. 



Leach's Petrel. 

 Thalassidroma leucorrhoa VIEH,., Nov. Die,; 181H. 



DESCRIPTION. 



Sr. CH. Form, robust. Size, medium. COLOR. Adult. Sooty-brown throughout, darkest on wings and tail, and 

 ashy in a line through wing. The upper tail coverts and base of lower are white. Iris, brown; bill, feet and webs, black. 



OBSERVATIONS. 



Nestlings are covered with black down. Known by the lougish bill, short legs, and brack webs to feet. Distributed, 

 in summer, from the coast of Maine, northward. Winters off the coast of the Southern States. 



DIMENSIONS. 



Average measurements of specimens from North America. Length, 8'45; stretch, 18'50; wing, 6'25; tail, 3'25; bill, '72; 

 tarsus, 1'02. Longest spacitnsa, 8'1) ); greatest extant of wing, 19'OJ; bags-it wing, 6'5,); tail. 3 - 5D; bill, '75; tarsus, 1 05. 

 Shortest specimen, 8'00; smallest extent of wing, 18'00; shortest wing,6'00; tail, 3-00; bill, '70; tarsus, 1-00. 



DESCRIPTION OF NESTS AND EGGS. 



Egys, placed in burrows, one in number, elliptical in form, chalky-white in color, with the shell brittle, dotted finely 

 on larger end, often in a ring, with purplish-red and lilac. Dimensions from '90 x 1'25 to I'OO x 1'36. 



HABITS. 



On the fifteenth of July, some years ago, in company with some ornithological friends, 

 I stood on a small, low island, just off Grand Menan. As this spot of land contained only 

 some two or three acres, we could see over its entire surface, and to all appearances, there 

 was not a living thing on it, larger than a beetle; yet really, it was tenanted by hundreds 

 of interesting birds, and a closer inspection soon disclosed their whereabouts. Walking 

 toward the middle of the island, we distinctly perceived the peculiar, oily odor which is so 

 characteristic of Petrels of all species, and looking down among the little hummocks at our 

 feet, we observed numerous holes among the somewhat luxuriant growth of grass, each of 

 which was the entrance to a burrow of a Leach's Petrel. The holes were about four inches 

 in diameter and of varying depths, from six inches to four feet, straight or crooked, some 

 with two or even three entrances, and all had been drilled in the peculiar soil, which con- 

 sisted of a light, black loam, by the birds. The extremity of the burrows was slightly en- 

 larged and the single egg was placed in it, frequently on a little dried grass. It was rare 

 to find an egg which did not have a bird over it, while in a few holes, there were two birds, 

 but then there were never any eggs. Usually the birds would bite quite fiercely and strug- 

 gle when they were being removed, then, almost as soon as they saw daylight, up would 

 come about two tea-spoonfuls of clear, yellow oil, filling the air with its peculiar odor. If 

 the birds were placed on the ground, they would run away and conceal themselves among 

 the grass; if thrown in air, would mount upward, though invariably disgorging the oil be- 

 fore going far, circle about the spot a few times, then fly out to sea. If not forcibly re- 



