No. 31657 is similar to _E. wrightii_ (Wright's Flycatcher); however, the outmost (tenth) primary is equal to or slightly larger than the fifth primary. Yet, the underparts of No. 31657 are darker and more uniform in coloration than those of typical representatives of _E. wrightii_. Miller, Friedmann, Griscom, and Moore (1957:88) stated that Hammond's Flycatcher is "transient" in Coahuila. Burleigh and Lowery (1942:193-194) reported that _E. hammondii_ was the most prevalent of the small flycatchers in southeastern Coahuila. They (_loc. cit._) obtained specimens of this flycatcher from the Chorro del Agua and Diamante Pass. Miller (1955a:167) characterized _E. hammondii_ as a common migrant, "chiefly in stands of low oaks in the pine-oak belt but also occasionally in the desert scrub" of the Sierra del Carmen. _Empidonax wrightii_ Baird.--Amadon and Phillips (1947:578) reported one Wright's Flycatcher from Las Delicias. Miller (1955a:167) stated that this species was a common migrant and occurred chiefly in the lower oak belt and in the desert scrub. Sutton and Burleigh (1939a:34) obtained specimens of _E. wrightii_ from San Pedro on January 29. _Empidonax griseus_ Brewster.--Sutton and Burleigh (1939a:34) noted that the Gray Flycatcher was common "in the San Pedro region" and collected two at San Pedro on January 29. Burleigh and Lowery (1942:194) collected specimens "near the Chorro del Agua, at Saltillo, and ... in the open desert some twenty miles west of Saltillo." **_Empidonax affinis trepidus_ Nelson.--_Specimen examined:_ one, [Male] 32750, from 13 mi. E San Antonio de las Alazanas, 9950 ft., July 6, 1955. Ridgway (1907:576) previously reported the little known and poorly defined Pine Flycatcher from Sierra Guadalupe. Because of its small size (wing, 75 mm.; tail, 65 mm.), No. 32750 is referable to _E. a. trepidus_. No indication of breeding of the subspecies _trepidus_ exists for Coahuila. Nevertheless, the date (July 6) on which No. 32750 was obtained suggests that this flycatcher may breed in southeastern Coahuila. *_Empidonax difficilis hellmayri_ Brodkorb.--_Specimen examined:_ one, [Male] 31469, from Sierra del Pino (=5 mi. S, 3 mi. W Acebuches), May 13, 1954, measurements: wing, 71 mm.; tail, 65 mm.; culmen, 11.5 mm.; tarsus, 17.0 mm. Miller (1955a:167) reported that the Western Flycatcher breeds in the Sierra del Carmen, from 6800 to 7500 feet. According to Miller, Friedmann, Griscom, and Moore (1957:91), this subspecies has been recorded from Sierra Guadalupe. No. 31469 closely resembles, especially in measurements, the specimens of the Western Flycatcher from the Chisos Mountains of Texas as reported by Brodkorb (1935:2). _Empidonax difficilis_ subsp.--Burleigh and Lowery (1942:194) obtained a specimen of _E. difficilis_ "near the summit of Diamante Pass" that they tentatively identified as _E. d. salvini_. However, they considered the specimen as possibly _E. d. immemoratus_ or _E. d. occidentalis_.