(syn. Anas Ϯ Laysan Duck A. laysanensis) Gr. ὁριζω horizō to limit; νηττα nētta duck; "The Laysan teal, Anas laysanensis, is a bird of considerable interest by reason of its rarity and its limited island distribution. ... As it is not referable to any other known genus, it becomes necessary to provide a new monotypic generic group for its reception, as follows: Horizonetta, gen. nov. Ϯ. Chars. gen.— Similar to Anas Linnaeus, but bill more spatulate, decidedly wider terminally than at base, more depressed and slightly upturned; basal portion of culmen more elevated, narrower and more sharply ridged; nail of maxilla more triangular; lamellae of maxilla and mandible much less well developed, in places even obsolescent; and tertials relatively longer. Type.— Anas laysanensis Rothschild. Remarks.— Excepting Anas Linnaeus, the nearest ally of this peculiar genus is apparently Querquedula Stephens. ... Ϯ from ὁριζω, limito; νηττα, anas." (Oberholser 1917).