I have taken the authority of Professor Temminck for the accuracy of the generic types of this genus under its present modification.
CASTNIA Fabricii,
Red underwing Day-moth.
Generic Character.
Antennæ clavatæ, clavo elongato, cylindraceo, fusiformi, ad apicem unco brevi, acuto armato. Palpi breves, graciles, haud prominentes, articulo ultimo nudo, obliquè verticales. Vertex ocellatus? ocello oculum juxta utrumque posito.
Obs. Caput parvum; alarum basis squamis conspicuis, elongatis imbricata.
Antennæ clubbed; club elongated, rounded, fusiform, ending in a short acute hook. Palpi short, slender, not projecting beyond the front, the last joint naked, obliquely vertical. Crown with a small ocellus? adjoining each eye.
Ob. Head small: base of the wings covered with conspicuous, lengthened, imbricate scales.