9. OCEANODROMA MACRODACTYLA, Bryant. 



(GUADALUPE FORK-TAILED PETREL.) 



(Plate 5a.) 



Oceanodroma leucorrhoa (nee Vieill.), Bryant, Bull. Calif. Acad., II., p. 276 (1887). 

 Oceanodroma leucorrhoa macrodactyla, Bryant, Bull. Calif. Acad., II., p. 450 (1887) ; 



id. Pr. Calif. Acad., II., p. 252 (1889). 

 Oceanodroma macrodactyla, A. O. U. Checkl. N. Amer. Birds, 1889, p. 5, No. 106 ; 



Salvin, Cat. Birds Brit. Mus., XXV., p. 351 (1896) ; Oates, Cat. Eggs Brit. 



Mus., I., p. 149 (1901) ; Godman, Biol. Centr.-Amer., Aves, III., p. 430 (1904). 



O. castro similis, sed valde major, supracaudalibus late nigro terminatis, 

 pedibusque fortioribus distinguenda. 



The larger size of O. macrodactyla distinguishes the species from O. castro, which it 

 otherwise closely resembles. As in the latter the white upper tail-coverts are broadly 

 tipped with black, but the wing-patch is somewhat paler, being of a light chocolate 

 brown and of a less ashy-grey tint ; the light patch occupies the median and minor wing- 

 coverts and extends to the long inner secondaries. 



I have examined two specimens in the British Museum and three in the collection 

 of the Hon. Walter Rothschild. The wing measures from 6.3-6.6 inches in the males, 

 and in the females from 6.5-6.7 inches. The length of the middle toe and claw is from 

 1.05-1.1 inch, and of the tarsus 1.2-1.25 inch. The foot is decidedly larger than 

 that of O. castro, the tarsus in the latter species being 0.9-0.95 inch, and the middle 

 toe and claw 0.9-1.0 inch. 



This Storm-Petrel seems to be restricted in its range to the vicinity of the 

 island of Guadalupe, off the coast of Southern California. 



Eggs from this island, presented to the British Museum by Mr. Anthony, are white, 

 marked at the larger end with minute spots of a faint reddish colour. Axis, 1.4-1.45 

 inch; diam., 1.1. 



Adult male. General colour above sooty-black, with a very distinct shade of 

 plumbeous-grey ; the scapulars and lesser wing-coverts black ; the median and 



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