Measurements of our specimens agree well with the average measurements of typical _M. t. cooperi_. According to Ridgway (1907:621), _M. t.

cooperi_ (then called _Myiarchus mexica.n.u.s mexica.n.u.s_) has been recorded from Sabinas. The size of the testes (147 mm.) of No. 32068 and the date (June 22) on which the specimens were collected indicate breeding by this species in the State.

*_Myiarchus cinerascens cinerascens_ (Lawrence).--_Specimens examined:_ total 7: [Female] 31045 from 15 mi. SE Boquillas, 1500 ft., March 16, 1952; [Male] 32070 from 12 mi. N, 12 mi. W Jimenez, 850 ft., June 19, 1952; [Female] 32071 from 2 mi. W Jimenez, 850 ft., June 20, 1952; [Male] 35413 from 6 mi. N, 2 mi. W Castillon, 3750 ft., June 30, 1953; [Male] 32072 from 9 mi. S, 11 mi. E Sabinas, June 14, 1952; [Female]

31584 from 17 mi. S Ocampo, 5300 ft., April 7, 1954; and [Male] 31673 from the west foot of Pico de Jimulco, 5000 ft., April 4, 1953.

The Ash-throated Flycatcher is common in Coahuila. All specimens examined by me from there are typical of _M. c. cinerascens_. Ridgway (1907:626) listed _M. c. cinerascens_ from Monclovia (=Monclova?) and Sabinas. Miller (1955a:166) found the species "only in the oak belt at 5000 feet, where it was common." Burleigh and Lowery (1942:193) recorded _M. c. cinerascens_ from "near Saltillo." d.i.c.kerman obtained No. 31584 in a mesquite-gra.s.sland-shrubby area. Miller, Friedmann, Griscom, and Moore (1957:78) stated that _M. c. cinerascens_ breeds in Coahuila.

_Sayornis phoebe_ (Latham).--Miller, Friedmann, Griscom, and Moore (1957:66) recorded the Eastern Phoebe from Coahuila on November 4-14.

*_Sayornis nigricans semiatra_ (Vigors).--_Specimens examined:_ total 2: [Female] 31046 from 1 mi. N Boquillas, 700 ft., March 7, 1952; and [Female] 31047 from Fortin (=33 mi. N, 8 mi. W San Geronimo), 3300 ft., March 27, 1952.

Of the Black Phoebe, the two subspecies _semiatra_ and _nigricans_ intergrade in Coahuila. Typical representatives of _S. n. semiatra_ are present in northern Coahuila. The under tail coverts of Nos.

31046-31047 are immaculate and white. Miller (1955:167) noted the two specimens collected from the Sierra del Carmen to have narrow dark shaft streaks on the under tail coverts. He (_loc. cit._) remarked also that "the marking of the under tail coverts may indicate a beginning of a gradient in increased darkening of these feathers toward _S. n.

nigricans_ in southern Coahuila."

*_Sayornis nigricans nigricans_ (Swainson).--Burleigh and Lowery (1942:193) collected several specimens of _S. n. nigricans_ "on the outskirts of Saltillo" and saw a pair at the Chorro del Agua on April 19.

*_Sayornis saya saya_ (Bonaparte).--_Specimens examined:_ total 4: [Female] 31049 from the Rio Grande (=17 mi. S Dryden, Terrell Co., Texas, in Coahuila), 600 ft., March 18, 1952; s.e.x ? 31048 from 10 mi. S, 5 mi. E Boquillas, 1500 ft., March 4, 1952; [Male] 31050 from Fortin (=33 mi. N, 8 mi. W San Geronimo), 3300 ft., March 29, 1952; and [Female] 32059 from 7 mi. S, 4 mi. E Bella Union, 7200 ft., June 25, 1952.

Say's Phoebe occurs commonly in Coahuila. Miller (1955a:167) obtained a female with an active brood patch in Boquillas Canyon of the Sierra del Carmen, and remarked that Marsh took a juvenile on September 2 at El Rincon. Sutton and Burleigh (1939a:33) saw this phoebe several times in southern Coahuila and obtained a male "near San Pedro" on January 29.

Burleigh and Lowery (1942:193) recorded this species as "a common breeding bird both on Diamante Pa.s.s and on the arid plateau around Saltillo." No. 32059 was a juvenile.

_Empidonax traillii brewsteri_ Oberholser.--Amadon and Phillips (1947:578) look a Traill Flycatcher of the subspecies _brewsteri_ at Las Delicias on August 11.

_Empidonax minimus_ (Baird and Baird).--_Specimen examined:_ one, [Male] 31470, from Sierra del Pino (=5 mi. S, 3 mi. W Acebuches), 6200 ft., May 13, 1954.

Amadon and Phillips (1947:578) obtained two Least Flycatchers at Las Delicias on August 12. d.i.c.kerman took No. 31470 in pine-oak vegetation.

_Empidonax hammondii_ (Xantus).--_Specimen examined:_ one, s.e.x ? 31657, from the north slope of Sierra Guadalupe (=11 mi. S, 7 mi. W General Cepeda), 7800 ft., April 20, 1953.

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 Pa.s.s. 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 h.e.l.lmayri_ 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 Pa.s.s" that they tentatively identified as _E. d. salvini_. However, they considered the specimen as possibly _E. d. immemoratus_ or _E. d.

occidentalis_.

Localities listed by Miller, Friedmann, Griscom, and Moore (1957:92) of _E. d. salvini_ and _E. d. immemoratus_ are south of twenty-three degrees north lat.i.tude whereas the range of _E. d. occidentalis_ includes parts of Nuevo Leon north of twenty-three degrees north lat.i.tude (_occidentalis_ intergrades with _h.e.l.lmayri_ at Cerro Potosi, Nuevo Leon, [Miller, Friedmann, Griscom, and Moore, _loc. cit._]).

Thus, the specimen from Diamante Pa.s.s probably is either _E. d.

h.e.l.lmayri_ or _E. d. occidentalis_.

**_Empidonax fulvifrons pygmaeus_ Coues.--Miller, Friedmann, Griscom, and Moore (1957:95) listed this subspecies of the Buff-breasted Flycatcher from the Sierra Guadalupe on April 21. This record represents the eastern limit of the range of _E. f. pygmaeus_ in northeastern Mexico.

**_Contopus pertinax pertinax_ Cabanis and Heine.--Burleigh and Lowery (1942:194) obtained one female Coues' Flycatcher "in a small gully just below the summit of Diamante Pa.s.s."

_Contopus virens_ (Linnaeus).--I judge from the paucity of records in the literature that the Eastern Wood Pewee is uncommon in Coahuila.

Burleigh and Lowery (1942:194) obtained two males at the Chorro del Agua, and remarked also that "it is possible that as far west as Saltillo, this species is a rather uncommon transient." Ridgway (1907:519) listed _Contopus virens_ from Sabinas.

*_Contopus sordidulus veliei_ Coues.--_Specimens examined:_ total 2: [Male] 31467 from Sierra del Pino (=5 mi. S, 3 mi. W Acebuches), May 14, 1954; and [Male] 31653 from the north foot of Sierra Guadalupe (=10 mi. S, 5 mi. W General Cepeda), 6400 ft., April 19, 1953.

Specimen No. 31467 of the Western Wood Pewee was obtained in pine and oak vegetation by d.i.c.kerman. Ridgway (1907:523) reported _Contopus sordidulus veliei_, under the name _Myiochanes richardsonii richardsonii_, from Sierra Encarnacion. Amadon and Phillips (1947:578) obtained a specimen of _C. sordidulus_ from Las Delicias. Miller, Friedmann, Griscom, and Moore (1957:83) remarked that the Western Wood Pewee breeds in the State.

_Nuttallornis borealis_ (Swainson).--Several records of the Olive-sided Flycatcher from Coahuila are present in the literature. Miller (1955a:167) reported it as a migrant in the desert at the base of the Sierra del Carmen on April 24. Miller, Friedmann, Griscom, and Moore (1957:82) reported this species from Ocampo on June 16. Amadon and Phillips (1947:578) obtained one at Las Delicias on August 16. Burleigh and Lowery (1942:194) collected two males "near the summit of Diamante Pa.s.s" on April 14.

*_Pyrocephalus rubinus mexica.n.u.s_ Sclater.--_Specimens examined:_ total 3: [Male] 32060 and [Female] 32061 from 12 mi. N, 12 mi. W Jimenez, 850 ft., June 19, 1952; and s.e.x ? 32062 from 2 mi. W Jimenez, 850 ft., June 20, 1952.

The Vermilion Flycatcher is common in Coahuila. Except in the northwestern part of the State, the subspecies _mexica.n.u.s_ is present throughout Coahuila. The size of No. 32060 (wing, 80 mm.; tail, 62 mm.) suggests that the specimen is an intergrade between _P. r. flammeus_ and _mexica.n.u.s_. _P. r. flammeus_ and _mexica.n.u.s_ seem to intergrade in northern Coahuila.

Burleigh and Lowery (1942:195) found _mexica.n.u.s_ to be "quite plentiful on the plains surrounding Saltillo." Sutton and Burleigh (1939a:33) noted the Vermilion Flycatcher "near San Pedro." Cory and h.e.l.lmayr (1927:92) listed _P. r. mexica.n.u.s_ from Sabinas. The size of the testes (64 mm. long) of No. 32060 and the dates (June 19 and 20) on which our specimens were collected indicate breeding.

_Pyrocephalus rubinus flammeus_ van Rossem.--This subspecies of Vermilion Flycatcher occupies the northwestern section of Coahuila.

Marsh and Stevenson (1938:287) took a specimen of _P. r. flammeus_ "near Santo Domingo, east of the Del Carmens...." Miller (1955a:167) re-examined this specimen and stated that "its affinity with the northwest race of the species seems correct in terms of the characters outlined by van Rossem (1934:353)."

_Eremophila alpestris enthymia_ (Oberholser).--Miller, Friedmann, Griscom, and Moore (1957:105) recorded this subspecies of Horned Lark wintering 4 mi. S Hipolito (November 2 to February 24). They reported also that _E. a. enthymia_ breeds in Coahuila (4 mi. S Hipolito ?).

*_Eremophila alpestris diaphora_ (Oberholser).--_Specimens examined:_ total 9: [Male] [Male] 32073-32078 and [Female] 32079 from 7 mi. S, 4 mi. E Bella Union, 7200 ft., June 25, 1952; and [Male] [Male]

31605-31606 from 14 mi. W San Antonio de las Alazanas, 6500 ft., January 9, 1954.

Burleigh and Lowery (1942:195) wrote that this subspecies of Horned Lark was uncommon "about Saltillo," but "fairly common" in Diamante Valley, at about 7000 feet. Oberholser (1902:863) recorded the subspecies _aphrasta_ from La Ventura. Ridgway (1907:326) listed _Otocoris alpestris aphrasta_ Oberholser from Saltillo and La Ventura.

However, Miller, Friedmann, Griscom, and Moore (1957:105) indicated that _E. a. diaphora_ rather than _aphrasta_ was recorded from Saltillo and La Ventura. Sutton and Burleigh (1939a:35) remarked that "specimens collected near Ramos Arizpe [in southeastern Coahuila]" proved to be _E. a. aphrasta_. However, this record might be questioned, as Miller, Friedmann, Griscom, and Moore (_op. cit._) indicated, because _diaphora_, rather than _aphrasta_, seems to occupy the southeastern sector of Coahuila. Possibly typical representatives of _aphrasta_ and/or intergrades between _aphrasta_ and _diaphora_ are present in western Coahuila; however, no records of _E. a. aphrasta_ exist from western Coahuila.

The sizes of Nos. 32073-32077 and 31605-31606 (wing, 98.0-101.5 mm., averaging 99.7 mm.), the bright yellow throat, and the vinaceous color of the hindneck characterize clearly the subspecies _diaphora_. The sizes of the testes (96 mm.; 85 mm.; 106 mm.; 84 mm.; 116 mm.) of Nos. 32073-32077, the size of the largest ovum (6.5 mm.) of No. 32079, and the juvenile (32078) are evidence of breeding of _E. a. diaphora_ in Coahuila.

*_Tachycineta thala.s.sina thala.s.sina_ (Swainson).--_Specimens examined:_ total 3: [Male] 31471, [Male] 31473, and [Female] 31472 from Sierra del Pino (=5 mi. S, 3 mi. W Acebuches), May 15, 1954, measurements: wings, 125, 118, 108 mm.; tails, 56, 54, 46 mm.

The two subspecies of the Violet-green Swallow, _thala.s.sina_ and _lepida_, intergrade in Coahuila. Specimens from different localities in the State represent various stages of intergradation between the two subspecies; generally those from northern Coahuila seem to be closer to _T. t. lepida_, and those from southern Coahuila are closer to _T. t.

thala.s.sina_. Nos. 31471-31473 are intergrades between _T. t.

thala.s.sina_ and _T. t. lepida_; in size the three resemble _T. t.

thala.s.sina_, but in green, rather than purple, backs and scapulars resemble _T. t. lepida_. The rumps of Nos. 31471-31473 show some purple with the green, but are nearer _thala.s.sina_ in this character.

Gonadal sizes (testes 107, 108 mm., one ovum 6 mm.) indicate that the Violet-green Swallow breeds in the Sierra del Pino.

*_Tachycineta thala.s.sina lepida_ Mearns.--Miller (1955a:167) reported that Violet-green Swallows taken in Boquillas Canyon of the Sierra del Carmen are intermediate between _T. t. lepida_ and _thala.s.sina_; however, he referred his sample to _lepida_ on the basis of short wing.

_Iridoprocne bicolor_ (Vieillot).--Miller, Friedmann, Griscom, and Moore (1957:114) reported the Tree Swallow from Hipolito on February 22.

_Stelgidopteryx ruficollis psammochrous_ Griscom.--Miller, Friedmann, Griscom, and Moore (1957:111) reported this subspecies of the Rough-winged Swallow from Saltillo.