BIRDS OF NORTH AND MIDDLE AMERICA. 



205 



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

 (43.7); graduation of tail, 38.1-53.3 (45.7).'' 



Adah femalc.—l^ength (skim), 527-571.5 (544.5); wing, 31»3.7-40S.1> 

 (400.7); tail, 210,8-232.4 (220.3); exposed culmen, ()G-68.0 (()6.!)); 

 depth of hill at nostrils, 22.9-25.4 (23.4); tarsus, 64-6i>.S ((36.9); mid- 

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



Clarion and San Benedicto islands, Revillag-igedo group, off western 

 Mexico; San Clemente and Santa Catalina islands, Santa Bar])ara 

 group, southern California. '^ 



Cornis cora.v sinuatus (not Corvus siuiiaius Wagler) Townsend, Proc. U. S. Nat. 



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



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



315, 318 (San Benedicto and Clarion islands). 

 Cortms cora.v clarioncnsis Rothschild and Haktert, Novit. Zool., ix, July 25, 



1902, 381 (Clarion i., Revillagigcdo group; coll. Tring Mus.). 



CORVUS CRYPTOLEUCUS Couch. 

 WHITE-NECKED RAVEN. 



Similar to C. covax sinuatus^ but decidedly smaller, with relatively 

 shorter and deeper l)ill, longer nasal i)lumes, and with the feathers of 

 the neck and V)reast pure white for at least the ))asal half. 



Adults (.sv,/v.s' (lUke). — 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 



« Three specimens; one each from Santa Catalina and San Benedicto islands, one 

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

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



^ Five specimens, from San Benedicto and San Clemente islands. 



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

 ments with that from Clarion Island, as follows: 



cNoneof 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 giveu by Messrs. Rothschild and Ilartert, 

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

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

 ment, and the Clarion Island specimen })inij liave 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. 



