BIRDS OF NORTH AND MIDDLE AMERICA. 



265 



nostrils, 23-25.4 (24.2); tarsus, 66.8-70 (68.4); middle toe, 43.2-44.2 

 (43.7); graduation of tail, 38.1-63.3 (45.7).'^ 



Adultfemale.—l,mgth (skins), 527-571.5 (544.5); wing, 393.7-408.9 

 (400.7); tail, 210.8-232.4 (220.3); exposed culmen, 66-68.6 (66.9); 

 depth of bill at nostrils, 22.9-25.4 (23.4); tarsus, 64-69.8 (66.9); mid- 

 dle toe, 40.4-45.7 (44); graduation of tail, 35.6-44.4 (41.1). » 



Clarion and San Benedicto islands, Revillagigedo group, off western 

 Mexico; San Clemente and Santa Catalina islands, Santa Barbara 

 group, southern California.'" 



Corvus corax sinuatus (not Corvus sinuatus Wagler) Townsend, Proc. U. S. Nat. 



Mus., xiii, 1890, 136 (San Benedicto I.). — Gkinnell, Pub. i, Pasadena Ac. 



Sci., 1897, 16 (San Clemente I., California). — Anthony, Auk, xv, 1898, 



315, 318 (San Benedicto and Clarion islands). 

 Corvus corax clarionensis Rothschild and Hakteet, Novit. Zool., ix, July 25, 



1902, 381 (Clarion 1., Revillagigedo group; coll. Tring Mus.). 



CORVUS CRYPTOLEUCUS Couch. 



WHITE-NECKED RAVEN. 



Similar to 0. coi'ax sinuatus, but decidedly smaller, with relatively 

 shorter and deeper bill, longer nasal plumes, and with the feathers of 

 the neck and breast pure white for at least the basal half. 



Adults {sexes alike). — Entirely glossy black, the upper parts (except 

 hindneck) with a violet sheen, the under parts faintly glossed with 

 bluish; feathers of hindneck, sides of neck, lower throat, chest, and 



a Three specimens; one eacli from Santa Catalina and San Benedicto islands, one 

 from Clarion Island, the latter measured by Messrs. Rothschild and Hartert, only 

 the wing, culmen, and depth of bill being measured. 



6 Fi-y^e specimens, from San Benedicto and San Clemente isla,nds. 



The two males from San Benedicto and Santa Catalina islands compare in measure- 

 ments with that from Clarion Island, as follows: 



c None of the specimens examined from San Benedicto, Santa Catalina, and San 

 Clemente islands are as small as the single specimen from Clarion Island (Revilla- 

 gigedo group) whose measurements are given by Messrs. Rothschild and Hartert, 

 except the length of the tarsus, which is in all of them less than in the latter; but 

 Borne allowance should doubtless be made for differences in methods of measure- 

 ment, and the Clarion Island specimen may have been an unusually small one. At 

 any rate, the island birds which I for the present refer to this form are evidently 

 nearer to it than to the mainland bird. 



