arneros, Nuevo Leon.

Specimens (31051, 29425-29428, 31635-31636, 32081-32082, 31607, and
31654) of the Mexican Jay increase in size from northern Coahuila to
southern Coahuila. The average length of the wings of Nos. 29425-29426
from Club Sierra del Carmen is 152 mm. whereas the average length of
the wings of No. 32081 from 7 mi. S and 4 mi. E Bella Union, of No.
31607 from 13 mi. E and 3 mi. S San Antonio de las Alazanas, and of No.
31654 from Sierra Guadalupe is 164 mm.

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.