C. lecontei has the same general form, but a much smaller bill.
Common Characters. Crown and back streaked with black upon an ashy, olive, or chestnut ground; beneath whitish, tinged across the breast with ochraceous or ashy, plain, or with blackish streaks on the breast. A light superciliary stripe.
A. Tail-feathers attenuated, acute at ends, much graduated. On the crown a median light stripe.
a. A dusky streak on each side of the throat, and one above the light ochraceous maxillary stripe.
1. C. henslowi. Bill very robust, .35 along culmen by .30 deep at base. Wing, 2.25; tail, 2.20. Head ochraceous or greenish olive, lighter on the throat; a blackish stripe on each side of the crown. Breast streaked with black at all ages. Hab. Eastern Province of United States.
b. No dusky streak on side of throat nor above the maxillæ.
2. C. lecontei. Bill very narrow, only .16 broad by .20 deep at base. Median stripe of the crown ochraceous for anterior third, the remaining part ashy-white; superciliary stripe wholly ochraceous; edge of wing white; breast sparsely streaked in the adult. Wing, 2.15; tail, 2.20. Hab. Plains west of the Missouri, from Texas to Dakota.
3. C. passerinus. Bill robust, .23, or more, broad, by .24, or more, deep at base. Median stripe of the crown ochraceous throughout; superciliary stripe yellow anteriorly, ashy posteriorly; edge of wing bright yellow, breast unstreaked in the adult, streaked in the young, in which the head stripes are ashy, with no yellow on wing or over lore.
Colors dark, the black markings predominating above. Ad. Anterior lower parts deep buff at all seasons. Juv. Dusky streaks on breast very distinct. Bill, .33 and .30; wing, 2.60; tail, 1.90. Hab. Eastern Province of United States, and West Indies … var. passerinus.