NATATORES — PROCELL ARID.E - THALASSIDROMA. 
291 
THE FORK-TAILED PETREL. 
Thalassidroma leachi. 
PLATE CXXXV. FIG. 295. 
(CABINET OF H. C. DE RHAM.) 
Procellaria leachi. Temminck, Man. Orn. Vol. 2, p. 812. Bonaparte, Jour. Acad. Nat. Sc. Vol. 6, p. 229, pi. 9. 
Thalassidroma id. Id. Ann. Lyc. N. Y. Vol. 2, p. 367. Nut. Man. Orn. Vol. 2, p. 326. Audubon, Birds of Am. 
Vol. 7, p. 219, pi. 459. Giraud, Birds of Long island, p. 372. 
Characteristics. Sooty greyish black. Tail deeply forked, subequal with the wings. 
Upper tail-coverts white, with dusky shafts. Tarsus 1*0. Length, 
8 inches. 
Description. Bill robust, O'8 long, as broad as high at the base, much compressed at 
the tip. Nasal tube slightly turned upwards, and obliquely truncated. Tail deeply forked, 
and of twelve feathers. Hind toe minute, with a conical claw. 
Color. Wings and tail black. Wing-coverts greyish at their tips, forming a broad band. 
Scapulars slightly tipped with light greyish. Vent on each side, and upper tail-coverts white. 
Chin and sides of the body light ash. Bill and feet, with the webs of the latter, black. 
Length, 8'0 - 8 • 5. 
The Fork-tailed Petrel is a northern species, but occasionally descends as low as the 
coast of this State. During violent gales, it is sometimes blown far inland, and has been 
seen in the interior of Pennsylvania and Virginia. Breeds from the coast of Maine north¬ 
wardly. Its geographical range along the coast of America extends from 40° to 55° north 
latitude. Occurs on both sides of the Atlantic. 
(EXTRA-LIM1TAL) 
T. pelagica, Linn. (Bonap. Ac. Sc. Vol. 6, pi. 8. Aud. B. of A. Vol. 7, p. 228, pi. 461.) Mother 
Carey’s Chicken. Tail even or slightly rounded; the wings extending a little beyond it. Bill 
and feet black. Tarsus 0-9. Rump and upper tail-coverts white; the shafts black. Hind toe 
obsolete, with a minute claw. Length, 5 • 5. Coast of Newfoundland. Breeds in the Shetland 
islands. 
37' 
