Page:Birds of North and Middle America partV Ridgway.djvu/40

12 :::::::: i. Tail more graduated; larger (total length about 170 mm.); adult male wholly black below Othello (extralimital).
 * ii. Tail less graduated; smaller (total length less than 150 mm.); adult males with sides and flanks white or grayish.

Hypolophus (p. 32).
 * gg. Bill relatively much smaller and weaker (exposed culmen shorter than middle toe with claw), less strongly uncinate; crest less conspicuously developed.
 * h. Tail at least four-fifths as long as wing; larger and stronger forms.
 * i. Bill larger and stouter, the exposed culmen much more than half as long as tarsus.
 * j. Feathers of forehead much developed, the crest occupying entire pileum; male with a white throat-patch and black jugular area, the remaining under parts fulvous.

Biatas (extralimital).
 * jj. Feathers of forehead short, semi-decomposed, the crest confined to crown and occiput; adult males with under parts barred with black and white, or else uniform gray or slate color (rarely streaked with white).
 * k. Bill more swollen, with tip less compressed, its width at frontal antiæ equal to its depth at same point, and equal to much more than half the distance from nostril to tip of maxilla; adult males conspicuously barred with black and white, or gray streaked with white, beneath, females rufous above.

Thamnophilus (p. 34).
 * kk. Bill less swollen laterally, more compressed terminally, its width at frontal antiæ less than its depth at same point and equal to not more than half the distance from nostril to tip of maxilla; adult males plain gray, slate color, or black below, females gray, olive, or brown above.

Erionotus (p. 47).
 * ii. Bill smaller and more slender, the exposed culmen not more than half as long as tarsus, its depth at frontal antiæ equal to not more than half the distance from nostril to tip of maxilla.

Rhopochares (extralimital).
 * hh. Tail less than three-fourths as long as wing; smaller and weaker forms

Dysithamnus(p. 52).
 * cc. Nostril more or less narrow and longitudinal, more or less distinctly operculate, or if broadly oval or roundish the remainder of nasal fossæ occupied by membraneous integument.
 * d. Plumage softer, more lax, and semi-decomposed, especially on rump. (Formicivoræ.)
 * e. Planta tarsi distinctly scutellate, at least on inner side or posterior margin.