PROCELLAUIID^ — THE PETRELS — OCEAXODKUMA. 413 



Two species of this genus are known, distinguished by the following chaructei-s : — 



1. O. furcata. Bluish ashy, the orbital region and wings (except greater coverts^ duaky. 



lL(h. North Pacific. 



2. O. Hornbyi. Forehead, cheeks, nuchal coHar, and lower parts white ; quilLs black ; rest 



of plumage dark gray, including a jugular band. Hub. North Pacific. 



Oceanodroma furcata. 



THE FORK-TAILED PETREL. 



Proccllaria furcata, Gmel. S. N. I. ii. 1788, 561. 



Thalassidrovia furcata, GoVLV, Vo}'. Sulphur, Birds, 1844,50, pi. 33. — Cassin, lUustr. B. Cal 



Tex. etc. 1855, 274, pi. 47. — Lawk, in Baird's B. N. Am. 1858, 829. — Baiud, Cat. N. Am. 



B. 1859, no. 640. 

 Oceanodroma furcata, Bomap. Consp. IL 1856, 194. — CouES, Pr. Ac. Nat. Sci. Philad. 1864 74- 



Key, 1872, 329 ; Check List, 1873, no. 591 ; ed. 2, 1882, no. 826. — IIidgw. Nom. N. Am. b' 



1881, no. 726. 

 Proccllaria orientalis, Pallas, Zoog. Rosso-As. II. 1826, 315. 

 " Thalassidroma cincrea, Gould." (Bonap. ) 

 Thalassidroma plumhca, Peale, Zool. Expl. Exp. Birds, 1848, 292. 



Hab. North Pacific Ocean, south to coast of Oregon. 



Sp. Char. Adult: Fine light cinereous, fading gradually to white on the chin and throat, 

 anal region, and crissum ; orbital region, longer scapulars, inner wing-coverts, anterior and outer 

 lesser coverts, alula), primary coverts, and remiges grayish dusky ; central lesser, middle, and 

 inner greater coverts, and tertials broadly edged with ashy white. Lining of the win" clouded 



with grayish dusky and ashy white, the former predominating. Bill wholly deep blacK ; iris 

 dark brown ; legs and feet dusky brown. Younger: Sinular, but colors much more dingy, with 

 little if any of a bluish cast. 



Length, about 8.50 to 9.00 inches; extent, 18.25 to 19.00; wing, 5.95-G.40 ; tail, 3.75-4.00, 

 forked for about 1.00; culmen, .55-60 ; tarsus, 1.00-1.10 ; middle toe .90-95. 



This species appears to be less of a wanderer than are most of its family, and to be 

 exclusively an inhabitant of the Northern Pacific Ocean. It is an interesting addi- 

 tion to the fauna of the United States made by the naturalists in the Wilkes Explor- 

 ing Expedition — having been previously known only as a bird of the Asiatic coast, 

 of the islands of the North Pacific, and of Russian America. It was found in large 

 numbers by this Expedition on the southern coast of Oregon. 



This bird was first noticed by Pennant in his " Arctic Zoology," and called by him 

 the " Fork-tailed Petrel." The only account given of it was, that it had been taken 

 among the ice between Asia and America. Subsequently Pallas referred to it as an 

 inhabitant of the coasts of Unalashka and the Kurile Islands. 



We next find it mentioned in the Zoology of the Voyage of the '' Sulphur," 1844, 



