(Bucerotidae; Ϯ Rufous-necked Hornbill A. nipalensis) Gr. ακερως akerōs hornless < negative prefix α- a- ; κερας keras, κερως kerōs horn; "Bucerotidæ. ... Aceros nipalensis, [drawing nos.] 600-602" (J. Gray 1844); "Although belonging to the group of large Hornbills, it differs conspicuously from them in being destitute of a casque, that remarkable addition to the bills of its relatives; instead of this the culmen is swollen at the base, and slightly elevated" (Elliot 1882); "Aceros J. E. Gray, Zool. Misc., 1844, p. 85. Type, by monotypy, Aceros nipalensis = Buceros nipalensis Hodgson." (Peters 1945, V, 263).