Vireo atricapillus.
6818
Sp. Char. (No. 6,818.) Top and sides of head and neck black; rest of upper parts olive-green. Wing and tail feathers almost black on their upper surface, the quills and rectrices edged with olive (paler on the exterior primaries), the wing-coverts with two greenish-white bands on a blackish ground. Broad line from bill to and around eye (not meeting on forehead) with under parts white; the sides of body olivaceous; the axillars and inner wing-coverts (perhaps crissum)
yellowish. Bill black; feet plumbeous; iris bright red. First quill less than half the second, which about equals the tenth; third little shorter than fourth (longest).
Female. With the black replaced by dull slate; lower parts ochraceous-white medially. Possibly a distinct species (Mazatlan).
(No. 6,818.) Fresh specimen: Total length, 4.75; expanse of wings, 7.25; wing from carpal joint, 2.12. Prepared specimen: Total length, 4.10; wing, 2.25; tail, 1.95.
Hab. Southern border of Western Texas; Mazatlan.
The black head of this species, as far as known, makes it unique in the genus. It is extremely rare, but three or four specimens being known.
We refer to this species a specimen—probably a female—obtained at Mazatlan, on the western coast of Mexico, in April, by Colonel Grayson (S. I., No. 55,046). This specimen differs from those from Texas in having the black of the head replaced by a dull dark slate-color, the olive above rather less virescent, and the lower parts not pure white, but somewhat buffy. As all the other essential characters are identical, there being in both the white space covering the whole lore, and orbital ring interrupted on top,—features not seen in any other species,—we have little hesitation in considering them the same species; which opinion is moreover strengthened by the fact, that among the Texas specimens, all with black caps, there are no females.
Habits. Of the general history and habits of this rare species very little is known. It was first met with by Dr. Woodhouse, on the 26th of May, 1851, in Western Texas. This was on the Rio San Pedro, within ten miles of its source. He found it among some cedars, and was attracted by its very singular notes. It was in continual motion, like a Wood Warbler, and was by him at first supposed to be one of those birds. He obtained two specimens, both of which proved to be males.