266 



BULLETIN 50, UNITED STATES NATIONAL MUSEUM. 



breast with basal half or more (concealed) pure white; bill, legs, aod 

 feet black; iris brown. 



Young. — Head, neck, and body dull black, the plumage of neck, 

 chest, and breast white beneath the surface; feathers of throat short, 

 not lanceolate; wings and tail as in adults; basal half of mandible 

 light-colored (flesh color in life?). 



Adult maZe.— Length (skins), 45Y. 5-508 (484); wing, 337-379 (355.5); 

 tail, 193-214 (199); exposed culmen, 52-59 (57); depth of bill at nos- 

 trils, 20-22.5 (21); tarsus, 58-68.5 (62); middle toe, 37.5-43.5 (40.6).« 



Adult female.— Length (skins), 439.5-^89 (459); wing, 327.5-360.5 

 (347.5); tail, 181.5-211 (195.5); exposed culmen, 49.5-58 (53); depth of 

 bill at nostrils, 20-22.5 (22); tarsus, 55.5-64 (59); middle toe, 35-42.5 

 (38).''- 



Great Plains, from southeastern Wyoming (Cheyenne) and western 

 Nebraska (Cherry County, Sidney, etc.), southward to central Mexico, 

 through States of Chihuahua, Coahuila, Nuevo Leon, and Tamaulipas, 

 and Guanajuato; westward through New Mexico and Arizona to coast 

 of southern California (Los Angeles County). 



Corvus cryptoleucus Couch, Proc. Ac. Nat. Sci. Phila., vii, no. ii., 1854, 66 (Tamau- 

 lipas, n. e. Mexico; coll. U. S. Nat. Mus.). — Bated, Eep. Pacific R. R." Surv., 

 ix, 1858, 565; ed. 1860 (Birds N. Am.), atlas, pi. 22; Rep. U. S. and Mex. 

 Bound. Surv., ii, pt. ii, 1859, 20 (Janos and Charco Escondido, Tamaulipas); 

 Cat. N. Am. Birds, 1859, no. 425. — Kennekly, Rep. Pacific R. R. Surv., x, 

 pt. vi, 1859, 31, pi. 22 (Llano Estacado, Texas).— Dresser, Ibis, 1865, 494 

 (Eagle Pass, Texas). — Butcher, Proc. Ac. Nat. Sci. Phila., 1868, 150 (Laredo, 

 Texas).— Cooper, Orn. Cal., 1870, 284 (Arizona; Texas).— CouES, Check 

 List, 1873, no. 227; 2d ed., 1882, no. 339; Birds N. W., 1874, 206.— Aiken, 

 Proc. Bost., Soo. N. H., 1872, 203 (e. base Rocky Mts., Colorado) ; Am. Nat., 

 vii, 1873, 16 (Cheyenne, Wyoming) .-Eidgway, Bull. Essex Inst., v, 1873, 

 184 (Colorado); Field and Forest, June, 1877, 208 (Boulder Co., Colorado, 

 breeding) ; Nom. N. Am. Birds, 1881, no. 281. — Baird, Brewer, and Ridgway, 

 Hist. N. Am. Birds, ii, 1874, 233, 242, pi. 37, fig. 8 (bill); iii, 1874, 518 



aThirteen specimens. 

 * Fourteen specimens. 



Specimens from the Lower Rio Grande Valley seem to average smaller than those 

 from Arizona to western Texas, as the following measurements show: 



