14mm, 16mm. The forewing facies resembles that of some Hypena Schrank species such as similata Moore, where a rich brown basal half is divided from a paler distal half by a fine, straight, transverse boundary. The distal half grades darker brown with some rufous tints towards the margin and contains an irregular row of fine submarginal dots that are also as in some Hypena. However, the distal margin is angled centrally and is slightly concave anterior to this angle rather than evenly curved. The male abdomen is typical of the Mecistoptera group, however. The eighth segment is of the framed corematous type, and distinguished by an omega-shaped sternal frame and a semicircular excavation between the apodemes of the tergite. The genitalia have valves as in Acidon, but the main process is in the central pleat rather than subbasally in the saccular part, and terminates acutely at about one third. There is also an appressed acute spur on the costal process. The aedeagus is short, broad, and the vesica has two clusters of spines, each one on a distinct diverticulum; similar spines are seen in Mecistoptera loedli sp. n. (p. 162). The female genitalia are also typical of the generic complex, the ductus short with a broad ostium, and the corpus bursae relatively large and somewhat trilobed.
Holotype. BRUNEI: 30-60m, Ulu Belait, lowland forest, 28 Jan 79 (Lt. Col. M.G. Allen), BM noctuid slide 19659.
Paratype. SARAWAK: Gunong Mulu Nat. Park, R.G.S. Exped. 1977-8 (J.D. Holloway et al.), Site 23, April, W. Melinau Gorge, 250m, 430558, FEG 4, limestone forest, BM noctuid slide 19658.
Taxonomic note. There is a third, worn specimen, a female, from the paratype locality. An externally similar species occurs in Peninsular Malaysia (a male from Gunong Ijau; slide 19657), and has a similar structure of the eighth segment of the abdomen, but the genitalia, though also similar, have several distinct features: the apex of the central process is curved and rounded rather than acute; there is no costal spur; the aedeagus is much broader, and the vesica has one of the pair of clusters of spines of pseudohypena doubled.
Geographical range. Borneo.
Habitat preference. All three Bornean specimens are from lowland forest.
14mm,