Key to Scientific Names in Ornithology
(Tyrannidae; Ϯ Northern Bentbill O. cinereigulare) Gr. ογκος onkos bulk, weight; στομα stoma, στοματος stomatos mouth; "rostro compressiusculo, crassiusculo; culmen carinato, incurvo ... This Todirostrum differs slightly in the form of the bill from the ordinary members of the genus, that part being rather thicker, and with the culmen elevated and more incurved than in the typical species of the group" (P. Sclater 1856); "Genus ONCOSTOMA. 1269. ONCOSTOMA CINEREIGULARE. Todirostrum cinereigulare, Sclater, P.Z.S. 1856, p. 295" (P. Sclater 1862).