450 CALIFORNIA ACADEMY OF SCIENCES. 



DESCRIPTION OF A NEW SUBSPECIES OF PETREL FROM 

 GUADALUPE ISLAND. 



BY WALTER E. RRYANT. 

 Read July 18, 1887. 



A series of fourteen specimens of Oceanodroma, collected 

 by myself on Guadalupe Island off Lower California in 

 March, 1886, were assigned to the species leucorhoa (Leach's 

 Petrel), in my paper on the ornithology of that island/ 



In a foot note, reference was made to the considerable 

 excess in size of the Guadalupe Island specimens over 

 Leach's Petrel of the Atlantic Coast, but from lack of 

 sufficient material for comparison I was unable to satisfac- 

 torily determine their differences, although strongly inclined 

 to consider it a distinct race. My supposition has since 

 been confirmed by several prominent ornithologists, and by 

 comparison with typical specimens of Leach's Petrel from 

 Alaska and coast of Massachusetts, which were kindly loaned 

 from the Smitiisonian Institution. 



The Alaskan birds seem to be the same size as those from 

 the Atlantic Coast, and of about the same color. A single 

 female from Alaska (No. 102,281 Smithsonian Coll.), is 

 nearly as dark as the Guadalupe birds, but the upper tail 

 coverts are much whiter and the measuremeuts less. 



For this well marked local variety, I propose the name 



Oceanodroma leucorhoa macrodactyla, subsp. nov. 



GUADALUPE PETREL. 



Subsp. Char. — Similar to 0. leucorJioa, but larger and dark- 

 er. 



^ Additions to the Ornithology of Guadalupe Island. Bulletin California 

 Academy of Sciences, No. 6, pp. 269—318. 



