Diagnosis. The forewings are strikingly narrow, elongate, apically acute, with the tornus obtuse, almost forming a gentle curve from the oblique distal margin to the dorsum. The ground is a speckled, dark greyish brown. There is an obscure black discal mark, and a longitudinal streak along Rs and curving from it gently forwards to the apex. This streak is paler than the ground, becoming more distinctly so over the apical third. The female has a much paler forewing ground in which the markings are more conspicuous.
Taxonomic note. The original description noted differences from H. longipennis Walker (India, China, Taiwan), particularly the shorter discal cell on the hindwing. Prout (1932) described H. tumidicosta from Java. It has a similarly short hindwing cell to brevicella, and Prout indicated that it might be merely a local race thereof. A further related species, H. tripunctata Bethune-Baker, occurs in New Guinea and Seram, with both sexes resembling the female of brevicella. The male and female genitalia are very similar in all those species.
Geographical range. Borneo.
Habitat preference. This is a montane species described from a single specimen taken at an unspecified altitude on G. Murud in Sarawak but recorded subsequently from G. Kinabalu with six specimens taken between 1500m and 1930m.
