Page:Birds of North and Middle America partV Ridgway.djvu/187

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a. Maxillary tomium with a distinct (though small) subterminal notch; outer toe united to middle toe by the whole of its first and second phalanges and at least half of its third phalanx; tarsus indistinctly scutellate (smooth on inner side); tail less than three times as long as tarsus, the rectrices with very rigid shafts, whose denuded tips are not protruded. (Sclerurinæ.) Sclerurus (p. 163). aa. Maxillary tomium without trace of notch; outer toe united to middle toe by not more than whole of its first and second phalanges (usually by less than whole of its first phalanx); tarsus distinctly scutellate; tail more than three times as long as tarsus, the rectrices without rigid shafts or else with the attenuated or acuminate tips not denuded but protruded. (Furnariinæ.)
 * b. Maxilla with tip not at all decurved, but with tomia ascending (more or less strongly) terminally; mandible strongly recurved (falcate) terminally.
 * c. Outer toe not conspicuously (though distinctly) longer than inner toe, reaching (without claw) only to middle of subterminal phalanx of middle toe; outer toe with first and second phalanges united to middle toe; bill relatively shorter and stouter, the exposed culmen decidedly shorter than tarsus; tip of rectrices normal

Xenops (p. 170).
 * cc. Outer toe conspicuously longer than inner toe, reaching (without claw) much beyond middle of subterminal phalanx of middle toe; outer toe with only its first phalanx united to middle toe; bill relatively longer and more slender, the exposed culmen as long as tarsus; tips of rectrices (except lateral ones) attenuated, stiffened, and decurved.

Pygarrhicus (extralimital).
 * bb. Maxilla with tip more or less distinctly decurved, the tomia more or less decurved or descending terminally; mandible not recurved terminally (or else tip of maxilla decurved).
 * c. Nostril narrow, longitudinal, distinctly operculate.
 * d. Tarsus shorter than middle toe with claw; outer toe with first phalanx and at least part of second phalanx united to middle toe. (Margarornithes.)
 * e. Wing longer (nearly four times to more than four times as long as tarsus) and more pointed, the primaries exceeding secondaries by at least length of exposed culmen, sometimes by length of tarsus; bill relatively shorter, the exposed culmen much shorter than middle toe without claw; inner webs of remiges crossed by a broad band or with an extensive basal area of buff or ochraceous.
 * f. Tail graduated for only about one-third its length, with tip of rectrices (except outer ones) excessively acuminate, the slender points conspicuously protruded; wing more than four times as long as tarsus; inner webs of remiges crossed by a broad sub-basal band of buff or ochraceous

Margarornis (p. 177).
 * ff. Tail excessively graduated (for much more than half its length), with tips of rectrices not distinctly acuminate, the minute slender points