Description.

Body strongly convex dorsally, cylindrical and fairly elongate; dorsal and ventral surfaces strongly polished. Color piceous black; legs and antennae also black, though club segments of the somewhat reddish.

Head punctate, punctures with long setae anteriorly; transversely quadrate in general appearance; clypeus bi-arcuate and distinctly separated by a transverse carina whose basal portion is fairly broadly quadrate, rather long, ca. 0.3 mm length. Eyes: canthus well developed, strongly concave at middle, with anterior corner slightly produced outward as an angular lobe and posterior one very strongly produced outward as a fairly sharply pointed projection, ca. 1.2 mm width. Mandibles shorter than head, simply formed at postero-basal portion, with an upright process which is simply formed and without an implicit inner tooth, evenly and circularly incurved, and rounded distally; left mandible with two small obtuse teeth below and above at middle of inner margin, right one bearing a small obtuse tooth at the same place, with apex scarcely tumid at inner portion. Mentum slightly transverse, with anterior margin notched in widely opened at middle and forming arcuate lobe on each side, densely, coarsely and shallowly punctate, the punctures partly becoming aspirate, partly chained and forming irregular transverse sculptures. Antennae with 10 segments, 3rd to 7th one successively and very slightly broadened apically, club segments ordinary in size.

Pronotum strongly convex dorsally, distinctly long and elongate, ca. 1.4 times as wide as long, wider than elytra; median longitudinal groove along midline not strong. Pronotal punctuation more uniformly punctate, rounded in middle and obliquely truncated behind, with marginal border thick, anterior angles a little expanded laterally as rounded lobe; posterior angles obliquely truncated; basal margin gently rounded in middle and very weakly sinuous on each side, with marginal border thick, scarcely serrate have a minute central process at posterior carina.

Scutellum tongue-shaped, rounded at apex, smooth marginally, very densely and strongly punctate medially.

Elytra somewhat reddish, ca. 1.4 times as long as wide, strongly convex dorsally, with humeral tooth weak, but not sharply pointed; disc of each elytron with nine striae and 9 intervals; striae broadly and rather shallowly grooved, 1st to 8th stria arranged with a longitudinal row of coarse punctures which are dense or partly chained, distinctly invading both margins of intervals and circular to semicircular in shape, 9th stria very broad, surface shiny.