The genus was revised by Lödl & Gaal (1998). The species are large with striking facies that shows at least some degree of sexual dimorphism. In extreme instances, e.g. the type species, males have rather ochreous khaki to medium-brown forewings with a paler costa and a transverse, straight to sinuous postmedial fascia, and in females the ground is dark brown with an almost white costa and fasciation. In A. paritalis Walker, the females are a similar khaki to the males, and the fasciation is more obscure. In A. albitibiata Wileman & West (holotype only, from Luzon, Philippines) the male is of the female form. The hindwings of both sexes are a brownish grey, females usually with a fine, faint, postmedial fascia and males with a distinct concavity on the margin posterior to CuA2, making the dorsum appear lobed, and an amplexiform costal zone. In both sexes, the forewings are triangular as in Hypena, the females having a more convex distal margin and a slightly falcate apex. Most species have a punctate black submarginal, the black dots sometimes enclosing white distad as in some Hypena.
The male antennae are ciliate. The labial palps are long, directed forwards, the second segment much longer than the third as in the Hypena group.
The male abdomen has the eighth segment of a modified framed corematous type, and there are distinctive apodemes on A3. The genitalia have the uncus long, slender, tapering with a slight apical hook; it is strongly flexed between one-third and two-thirds. The tegumen is somewhat rectangular in overall shape, and there is a deep, broad saccus. The valves are triangular or a curved paddle shape, broader distally, with setae concentrated around the margins. There is a diagnostic pair of spines arising subcostally at one third and directed towards the ventral margin of the valve. The aedeagus is straight, tubular, with a small vesica.
The female genitalia have a short, broad, darkened and crinkled ductus bursae that leads into a small, pyriform corpus bursae, the two together no longer than the eighth segment is broad.
In addition to the four species referred to above and below, the genus includes A. sinuosa Wileman & South (Taiwan).
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