340 NORTH AMERICAN BIRDS. 



has a longer tarsus and a different style of coloration. The species are dis- 

 tinguished as follows : ■^- 



S. nigricans. Sooty black ; abdomen and edge of outer web of lateral 

 tail-leather pure white. 



a. Lower tail-coverts pure white. 



Greater wing-coverts paler toward tips of outer webs. Wing, 

 3.60; tail, 3.45. Hab. Pacific Province, United'States, and Mex- 

 ico .......... var. nigricans. 



b. Lower tail-coverts blackish. 



G-reater coverts not appreciably paler at ends. Wing, 3.35 ; tail, 

 3.30. Hab. Middle America, north of Panama . var. aqua ticus} 



Both rows of wing-coverts distinctly tipped with white ; white 



edgings of secondaries very conspicuous. Wing, 3.35 ; tail, 3.30. 



Ilab. New Grranada ; Venezuela . . . var. cinerascens.^ 



S. fuscus. Grayish-olive above, and on sides of breast ; beneath (including 



throat) white, tinged with sulphur-yellow. Wing, 3.40 ; tail, 3.20. Hab. 



Eastern Province United States ; Eastern Mexico. 



S. sayus. Brownish-ashy, the tail and upper tail-coverts black ; abdomen 

 and crissum deep ochraceous. Hab. Western Province of United States, 

 and whole of Mexico. 



Sayornis nigricans, Bonap. 



BLACK PEWEE. 



Tyrannula nigricans, Swainson, Syn. Birds Mex. Taylor's Phil. Mag. I, 1827, 367. — 

 Newberry, Zobl. Cal. & Or. Route, Rep. P. R. R. Surv. VI, iv, 1857, 81. Muscicapa 

 7iigricans, Aud. Orn. Biog. V, 1839, 302, pi. cccclxxiv. — Ib. Birds Am. I, 1840, 

 218, pi. Ix. Tyrannus nigricans, Nuttall, Man. I, (2d ed.,) 1840, 326. Myiobius 

 nigricans. Gray. Myiarchus nigricans, Cabanis, Tschudi Fauna Peruan. 1844 - 46, 

 153 (Peru). Sayornis nigricans, Bonap. Comptes Rendus XXVIII, 1854, notes Orn. 

 87. — Baird, Bh-ds N. Am. 1858, 183. — Heerm. X, S, 38. —Cooper, Om. Cal. I, 

 1870, 319. Aulanax nigricans, Cabanis, Cab. Journ. fiir Ornitli. IV, Jan. 1856, 2 

 (type of genus). — Ib. M. H. II, 68. Muscicapa scmiatra. Vigors, Zool. Beechey 

 Voy. 1839, 17. 



^ Sayornis nigricans, var. aquaticus. Sayornis aqitaticus, Sclater & Salvin, Ibis, 1859, 

 p. 119 (Guatemala). 



2 Sayornis nigricans, var. cineraccns. Sayornis cineracea, Lafr. Rev. Zool. 1848, p. 8. — 

 ScL. Catal. Am. Birds, 1862, 200. The above races are clearly shown to be merely modifications, 

 with latitude, of one type, by the series of specimens before us. Thus, specimens of »S'. nigri- 

 cans from Orizaba show more or less dusky on the lower tail-coverts, while in more northern 

 specimens (i. e. tyjncal var. oiigricans) there is not a trace of it. Typical specimens of aquaticus, 

 from Guatemala, show merely a more advanced melanism, the lighter markings on the wings 

 becoming greatly restricted ; there is still, however, a decided presence of white on the lower 

 tail-coverts. Specimens from Costa Rica (typical aquaticus) exhibit the maximum degree of 

 melanism, the white beneath being confined to a central spot on the abdomen. In cineraceus 

 (from New Granada) the white beneath is similarly restricted, but on the wings is very con- 

 spicuous, showing a reversion back to the character of nigricans, though surpassing the latter 

 in the amount of white on the coverts and secondaries. 



The S. latirostris (Aulanax I. Cab. & Hein. Mus. Hein. ii, p. 68 ; Sayornis I. ScL. Cat. Am. 

 B. 1862, 200), from Ecuador, we have not seen. It is probably also referrible to the same type. 



