Miller (1955a:169) indicated that the Mexican Jay breeds in the Sierra del Carmen. Burleigh and Lowery (1942:196) remarked that the species breeds at Diamante Pass. The sizes of the testes (12, 11 mm.) of Nos. 29425-29426, the size of the ovum (8 mm.) of No. 29428, and the short tail (126 mm.) of the immature female from 4 mi. N and 21 mi. W Cuatro Cienegas are also evidence of breeding by this species in the State. *_Corvus corax sinuatus_ Wagler.--The Common Raven seems to occur in low density in Coahuila. Miller (1955a:168) saw ravens in the pine-oak and cliff areas of the Sierra del Carmen, and took a breeding female at the head of Corte Madera Canyon, 7500 feet. Burleigh and Lowery (1942:196) found this species to be a bird of the higher slopes of the mountains although not uncommon in the broad open valley south of Diamante Pass. Sutton and Burleigh (1939a:35) took a male at Santa Rosa. *_Corvus cryptoleucus_ Couch.--_Specimens examined:_ total 4: [Male] 32080 from 2 mi. W Jimenez, 850 ft., June 20, 1952; [Female] 35404 (skeleton only) from 4 mi. N San Isidro (=16 mi. N Ocampo), May 10, 1954; and [Male] [Male] 31474-31475 from R. de Almendarez (=53 mi. NW Ocampo), May 11, 1954. The White-necked Raven occurs throughout Coahuila. Sutton and Burleigh (1939a:36) observed this species "in the vicinity of Saltillo," but not farther west. Burleigh and Lowery (1942:197) noted _C. cryptoleucus_ frequently "on the arid plateau around Saltillo" and obtained a specimen "in the high fertile valley south of Diamante Pass." Burleigh and Lowery (_loc. cit._) remarked that the White-necked Raven avoids the mountain slopes; 7000 feet was the uppermost limit of occurrence. The sizes of the testes (32080, 20 mm.; 31474: left, 12x20 mm., right, 10x16 mm.; and 31475: left, 10x16 mm., right, 10x14 mm.) of the specimens that I have examined and the dates (May 11, June 20) on which they were collected indicate breeding by the White-necked Raven in Coahuila. *_Parus sclateri eidos_ (Peters).--_Specimens examined:_ total 4: [Female] 32083 from 7 mi. S, 4 mi. E Bella Union, 7200 ft., June 25, 1952; [Male] 31609 from 2 mi. E Mesa de Tablas, 9000 ft., January 15, 1954; [Male] 31656 and [Female] 31655 from the north slope of Sierra Guadalupe (=11 mi. S, 7 mi. W General Cepeda), 7800 ft., April 20, 1953. The Mexican Chickadee is common in southeastern Coahuila. Miller, Friedmann, Griscom, and Moore (1957:133) stated that _P. s. eidos_ and _P. s. sclateri_ intergrade in southern Coahuila. The specimens that I have examined also show signs of intergradation, but are closer to _P. s. eidos_.