“My attention was drawn to this bird by a shrill, discontented chirp which accompanied its incessant motion in pursuit of insects. Three specimens only were seen, and all of them at one locality, near the head of the Rio San Pedro, or Devil’s River, to the valley of which it appeared to be confined, for, being aware of its novelty to the fauna of the United States, I kept a strict look-out, but did not meet with it elsewhere. “It was not at all shy, showing no concern when approached within a few rods. The procuring of a specimen was, however, a matter of some difficulty, as its constantly hopping or flying from branch to branch rendered an unobstructed shot the next thing to an impossibility. It was found in June, and the specimen obtained by me, now in the collection of the commission, is that of a male.” Our figure is of the natural size. DESCRIPTION AND TECHNICAL OBSERVATIONS. Genus Vireo. Vieillot, Ois d’Am., Sept. I, p. 83. (1807.) Size small; bill rather short, strong, wide at base, compressed towards the point, which is curved downwards, and sharp; upper mandible with distinct notches near the point; nostrils basal, large; wing moderate or rather short, with the third and fourth quills usually longest; tail rather short; legs long, rather slender. An American genus, containing six species. The Red-eyed Flycatcher (_V. olivaceus_), and others of the long-billed species, are not included, but have properly been embraced in a new group, _Vireosylvia_, Bonaparte. Vireo atricapillus. Woodhouse, Proc. Acad., Philada., VI. p. 60. (April, 1852.) Form. Small, but compact, and rather broad; bill rather short, acute; wing with the third and fourth quills equal; tail rather short, even at the end, or slightly emarginate. Dimensions. _Male._—Total length, 7½ inches; Wing, 2¼; tail, 1¾; expanse of Wings, 7¼. Color. _Male._—Head above and cheeks black; stripe before the eye, and entire under parts, white, tinged with greenish-yellow on the sides and flanks; back, rump, and upper tail-coverts, dark olive-green; quills brownish-black, with a greenish tinge, and edged externally with greenish-yellow; wing-coverts tipped with greenish-white; tail feathers brownish-black, edged externally with greenish-yellow; bill and feet dark; iris light red. Hab. Texas. Spec. in Mus. Acad., Philada., and Nat. Mus., Washington city. Obs. This is a very distinct and peculiar species of this genus, not at all resembling any other, and readily distinguished by its black head. It belongs, however, strictly to the same group as _V. flavifrons_, _V. solitarius_, _V. noveboracencis_, and others, and is one of the most interesting of the more recent additions to the ornithology of the United States. PICOLAPTES BRUNNEICAPILLUS.—La Fresnaye. The Brown-headed Creeper. PLATE XXV.—Adult Male.