Poospiza bilineata.
Gen. Char. Bill slender, conical, both outlines gently curved. Under jaw with the edges considerably inflected; not so high as the upper. Tarsi elongated, slender; considerably longer than the middle toe. Toes short, weak; the outer decidedly longer than the inner, but not reaching to the base of the middle claw. Hind toe about equal to the middle without its claw. All the claws compressed and moderately curved. Wings rather long, reaching about over the basal fourth of the exposed portion of the rather long tail. Tertiaries and secondaries about equal, and not much shorter than the lengthened primaries; the second to fifth about equal and longest; the first considerably shorter, and longer than the seventh. Tail long, slightly emarginate, graduated; the outer feather abruptly shorter than the others. Feathers broad, linear, and rather obliquely truncate at the ends, with the corners rounded.
Color. Uniform above, without streaks. Beneath white, with or without a black throat. Black and white stripes on the head.
We are by no means sure that the two North American specimens here indicated really belong to the genus Poospiza, but we know no better position for them. They may be distinguished as follows:—
Common Characters. Lores and beneath the eye black, a white orbital ring, white spot above the lore (in bilineata continued back in a superciliary stripe); a white maxillary stripe. Lateral tail-feathers, with outer web, and terminal border of inner, hoary or pure white.
A. Throat black in adult; sides not streaked.
A continuous white superciliary stripe.
1. P. bilineata. Black patch of throat covering jugulum, with a convex outline behind. Crown and back without streaks, concolored. Wing-coverts without white bands; lesser coverts ash. Wing, 2.75; tail, 2.85; bill, from nostril, .37; tarsus, .65.
No white superciliary stripe.
2. P. mystacalis. Black patch of throat not extending on jugulum; its posterior outline truncated. Crown and back with distinct black streaks. Back scapulars and rump rufous in contrast with the ash of head and neck. Wing-coverts with two narrow, sharply defined white bands; lesser coverts black. Wing, 2.80; tail, 3.30; bill, .40; tarsus, .80. Hab. Mexico.