Diagnosis. The type (OUMNH: 1814) lacks its head. The forewing pattern has the discal spot separated from the postmedial, which nevertheless has a slight concavity adjacent to it. Also, the narrow white submarginal, parallel to the postmedial, is not in extensive contact with the pale band adjacent to the postmedial on its distal side. The dark marks across the veins of the forewing margin are not broad, the most dorsal one being particularly linear compared to the other species. The male genitalia have the valve processes relatively weak, the exterior ones consisting of a small distal spur, the basal margin of which has a slight setose angle adjacent to a shallow lobe basal to it. The aedeagus vesica has a small horse-shoe of short spines.
Taxonomic note. Poole (1989) listed pallida Hampson (S. India) as a synonym of opiliusalis without comment, but it is treated as a distinct species in the BMNH curation and card index. It is also represented by only the holotype, which is a larger and more strongly marked specimen with a broader pale band distal to the postmedial.
Geographical range. Borneo.
Habitat preference. Only the type material has been seen, taken in Sarawak by A.R. Wallace, probably in the lowlands.
