Size very large. Colour dark chestnut, abdomen reddish-chestnut, shaded with black; legs testaceous, wings straw-coloured. Antennae with 40 segments; 1-3 fulvous, the rest dark chestnut. Head dark chestnut, mouth-parts paler. Pronotum dark chestnut, narrow and rounded anteriorly, the sides strongly convex, converging before the posterior margin, which is truncate: thus the form of the pronotum is a posteriorly truncate ellipse; median sulcus distinct, sides somewhat incrassate. Scutellum dark chestnut; in the form of an isosceles triangle, the apex pointing posteriorly. Sternal plates pale yellowish. Elytra broad and ample, somewhat cenvex and oblique posteriorly; smooth, dark chestnut. Wings ample, straw-coloured or testaceous; coriaceous and membranous parts scarcely differentiated. Legs reddish testaceous. Abdomen deep reddish chestnut, shaded with blackish near the base, rugulose, with a pair of smooth spots in the middle of each segment. Penultimate ventral segment of the male hidden by the 8th, which has a faint median sulcus and is produced posteriorly into a rather short obtuse triangle, not reaching the anal process; it is hidden in the female by the 6th, the furrow is obsolete, the hind margin produced into a very long narrow acuminate lobe extending almost to the apex of the anal process. Last dorsal segment in the male ample, longer than broad, with a shallow median depression; rough, with a mass of small tubercles; dorsal surface separated from the ventral by a row of minute sharp black tubercles; in the female somewhat shorter, but structure and pattern similar. Anal process in the male pentagonal; that is, the sides are at first convex, slightly emarginate at the base itself; outer angles marked by a short point, thence converging to an apical point; the edge itself is slightly thickened and studded with minute tubercles; under surface smooth with a shallow median sulcus; upper surface somewhat smoother than the last dorsal segment; in the female lanceolate, that is, more strongly emarginate at the base itself so that the sides form a sharp angle near the base, beyond which they converge to form an acute angle; edges studded with minute sharp tubercles, especially at the angles. Forceps with the branches deep red, darker at the apex, with minute pittings; in the male regularly arcuate in the asal third, then bent inwards at an obtuse angle and very ditinctly thickened, the inner margin straight and outer margin gently arcuate, rather blunt at the apex itself; in the female the branches are regularly curved and arcuate, sickle-shaped, very slightly thickened at the apex itself.
Length of body (without anal process), male, 40mm, female, 29-39mm; length of body forceps (with anal process), male, 5-7mm, female, 4-7mm.

不丹，缅甸，越南，印度，锡金