- [Ramphocænus] semitorquatus Sclater and Salvin, Nom. Av. Neotr., 1873, 73.
- Rhamphocænus semitorquatus Sclater, Ibis, 1883, 96 (Veragua, Panama; Antioquia, Colombia; crit.); Cat. Birds Brit. Mus., xv, 1890, 262 (Veragua; Antioquia). — Salvin and Godman, Biol. Centr.-Am., Aves, ii, 1892, 219 (La Balsa, Rio Sucio, and San Carlos, Costa Rica; Santiago de Veragua, Calovevora, and Lion Hill, Panama; Colombia). — Bangs, Proc. New Engl. Zool. Club, iii, 1902, 42 (Volcan de Chiriquí, Panama, 1,000-2,000 ft.). — Carriker, Ann. Carnegie Mus., vi, 1910, 612 (Caribbean lowlands to 1,500 ft., Costa Rica; habits).
- [Rhamphocænus] semitorquatus Sharpe, Hand-list, iii, 1901, 28.
- (?) Rhamphocænus cinereiveniris (not of Sclater?) Sclater and Salvin, Proc. Zool. Soc. Lond., 1879, 525 (Antioquia, Colombia; crit.).
Genus CERCOMACRA Sclater.
- Cercomacra Sclater, Proc. Zool. Soc. Lond., 1858, 244. (Type, Myrmothera cærulescens Vieillot.)
Medium-sized Formicariidæ (length about 120-135 mm.) with 10 rectrices, distinct rictal bristles, and color plain gray or blackish with concealed white dorsal patch and narrow white tips to wing- coverts (sometimes with broad white tips to lateral rectrices), the adult female of some species brown above, tawny or ochraceous below.
Bill shorter than head, moderately stout, rather broad and depressed basally, its width at frontal antiæ much greater than its depth at same point and equal to at least half the distance from nostril to tip of maxilla; culmen distinctly ridged, straight basally, gently decurved for about terminal half, the tip of maxilla distinctly but not conspicuously uncinate; maxillary tomium nearly straight, minutely notched subterminally; mandibular tomium nearly straight, minutely (very indistinctly) notched subterminally; gonys faintly convex (more decidedly so basally), moderately ascending terminally. Nostril exposed, posteriorly in contact with feathering of latero- frontal antiæ, small, broadly oval, margined above and posteriorly by very narrow membrane, with an internal tubercle showing within posterior portion. Rictal bristles distinct; feathers of chin and malar apex with distinct terminal setæ. Wing moderate, with longest primaries distinctly longer than secondaries; sixth, fifth and fourth, or fourth and fifth primaries longest, the tenth (outermost) one-half to nearly three-fifths as long as the longest, the eighth about as long as secondaries. Tail as long as wing or a little shorter, graduated (graduation about equal to length of tarsus), the rectrices (10) broad, rounded terminally. Tarsus much longer than whole culmen (a little more than one-third as long as wing), slender, the acrotarsium rather distinctly scutellate, the planta tarsi completely fused; middle toe, with claw, much shorter than tarsus (about as long as exposed culmen); outer toe, without claw, reaching to beyond middle of subterminal phalanx of middle toe, the inner toe
