Length (with mandibles) 9 mm., breadth at the shoulders not quite 3 mm. — Resembling C. sulcatus Westw. but considerably smaller and easily recognizable by the distinctly costate and very regularly punctate elytra and by the rounded ocular canthus. The front margin of the head is faintly concave, laterally diverging towards the ocular canthus, the latter with broadly rounded anterior angles, impunctate and with raised margins; the clypeus small, rounded anteriorly and punctate. The mandibles smooth and shining, slightly curved, with a small toothlike knob at the inner margin near the base; the basal two-thirds of the outer margin finely raised. The upper surface of the head shows a large triangular impression the top of which is directed towards the occiput; it is covered with punctures which along the front margin (base of the triangle) are smaller and more densely set than in the middle; a smooth, shining spot is present at the anterior portion of the inner orbits.