166 



PROCEEDINGS OP THE NATIONAL MUSEUM. 



VOL. 54. 



P[rocellaria\. Bullockii Fleming, Hist. Brit. Anim., 1828, p. 136 (St. Kilda 

 Island, Scotland ; based on the same specimen as Procellaria leachii Temminck). 



Th[alassidroma]. scapulata Kittlitz, Denkwiird. Reise Russ. Amer. Micronea. 

 und Kamte., vol. 2, 1858, p. 191 (Pacific Ocean off the coast of Japan, in 

 latitude 37° N.; longitude 148° 30' E.). 



Suhspecific characters. — Size large; plumage sooty brown, lighter 

 below; head slightly plumbeous; rump white; and tail much forked. 



Measurements. — Male:^ Wing, 145-157 (average, 152.9) mm.; tail, 

 77.5-88 (84.8); exposed culmen, 16-17 (16.4); height of bill at base, 

 5.8-6.8 (6.2); tarsus, 22-25 (23.8); middle toe without claw, 19.5-22 

 (20.6); fork of tail, 15.5-23 (19.3). Female:^ Wing, 148-163 (aver- 

 age, 155.6) mm.; tail, 80-90 (85.8); exposed cuhnen, 15-17.1 (16.1); 

 height of bill at 'base, 6-6.8 (6.3); tarsus, 23-25.8 (24.1); middle toe 

 without claw, 18.8-22 (20.6); fork of tail, 15.5-26.5 (19.7). 



Type-locality. — Maritime parts of Picardy, France. 



Geographic distribution. — -North Atlantic Ocean and North Pacific 

 Ocean: breeds from southern Greenland and Iceland south to Maine 

 and Ireland, and from the Aleutian and Commander Islands to the 

 Kuril Islands. Migrates east to Sicily, south in the Atlantic Ocean 

 to Virginia, the Bermuda Islands, the Equator, and casually even to 

 South Africa; in the Pacific Ocean to Japan and Midway Island. 



Remarks. — Petrels of this species from the Aleutian Islands and 

 the middle and western portions of the North Pacific Ocean, includ- 

 ing the Commander and Kuril Islands, appear to be shghtly darker 

 than birds from the North Atlantic Ocean, but this is probably due 

 to the age of the specimens rather than to any subspecific difference ; 

 and since our series does not show them to be satisfactorily different, 

 they must bear the name Oceanodroma leucorhoa leucorhoa. A speci- 

 men from the Ugashik River on the mainland of Alaska, west of the 

 Alaska Peninsula, taken, December 3, 1881, is apparently also refer- 

 able to this form. 



Average measurements of specimens from the different parts of 

 the range of this subspecies are as foUows: 



Birds of this species evidently become much more brownish and 

 sometimes paler after lying in the cabinet for a long term of years, 



> Ten specimens, from northeastern North America. 

 2 Eight specimens, from northeastern North America. 



