A. A broad white stripe above the eye, meeting across forehead.
1. P. montanus. Edges of wing-coverts, secondaries, and tail
scarcely paler than general tint above. Beneath ashy-whitish,
medially. Wing, 2.85; tail, 2.50; bill (along culmen), .50;
tarsus, .69; middle toe, .43; wing-formula, 45, 36, 7, 2;
graduation of tail, .18. _Hab._ Mountain regions of Middle
and Western United States.
B. No white stripe above the eye.
_a._ Tail as long as, or longer than, wing. Conspicuous white
edgings to wing-coverts, secondaries, and tail-feathers.