"On the whole, and in the absence of any information as to the habits of any species of Terenura, we are inclined to place the genus near Myrmotherula, notwithstanding the difference of coloration and the much longer tail".
"The bill is longer than that of Myrmotherula surinamensis, but is otherwise very similar. The wings are decidedly longer and less rounded. The tarsi are covered behind with large scutella, the sutures of which are, however, rather indefinite".
"Four or five species constitute the genus Terenura, all more or less rare birds. These are distributed over a wide area of Tropical America — one or two in Southeastern Brazil, one in Guiana, one in Eastern Ecuador, and T. callinota, a western and northwestern bird the range of which is given below"[1] [Veragua to Peru].
TERENURA CALLINOTA (Sclater).
RUFOUS-RUMPED ANTWREN.
Adult male. — Above greenish olive; cap black; lores and sides of head whitish; lower back bright chestnut; wings and tail blackish, with olivaceous edgings; wing-coverts black, broadly tipped with white; bend of wing and adjoining coverts bright yellow; beneath pale greenish yellow; throat and breast pale cinereous; under wing- coverts sulphur-yellow; whole length 4 inches, wing 2.2, tail 1.7.[2]
Western Panamá (Calobre, Verágua) through Colombia (Bogotá) and Ecuadór (Nanegál; Pallatanga) to central Peru (Roypaybamba).
- Formicivora callinota Sclater, Proc. Zool. Soc. Lond., 1855, 89, pi. 96 (Bogotá, Colombia; coll. Brit. Mus.,) 147 (Bogotá); 1858, 242 (Bogotá).
- Terenura callinota Taczanowski, Proc. Zool. Soc. Lond., 1874, 530 (Roypaybamba, centr. Peru); Orn. du Pérou, ii, 1884, 52. — Taczanowski and Berlepsch, Proc. Zool. Soc. Lond., 1885, 118 (Pallatanga, Ecuadór). — Sclater, Cat. Birds Brit. Mus., xv, 1890, 257 (Calobre, Verágua; Bogotá; Nanegál, Ecuadór). — Salvin and Godman, Biol. Centr.-Am., Aves, ii, 1892, 213. — Berlepsch and Stolzmann, Proc. Zool. Soc. Lond., 1902, 58 (Ropaybamba, Peru).
- [Terenura] callinota Sclater and Salvin, Nom. Av. Neotr., 1873, 72. — Sharpe, Hand-list, iii, 1901, 27.
Genus RAMPHOCÆNUS Vieillot.
- Ramphocænus[3] Vieillot, Nouv. Dict. d'Hist. Nat., xxiv, 1818, 112 (diagnosis but no type given). Ramphocænus Vieillot, Nouv. Dict. d'Hist. Nat., xxix, 1819, 5. (Type, R. melanurus Vieillot.)
- Rhamphocænus (emendation) Strickland, Ann. Mag. N. H., vi, 1841, 421.
- Acontistes Sundevall, Kgl. Vet.-Ak. Handl., 1835 (1836), 95. (Type, Ramphocænus melanurus Vieillot.)
- Scolopacinus Bonaparte, Proc. Zool. Soc. Lond., 1837, 119. (Type, S. rufiventris Bonaparte.)
