Carapace ornamented with several low mounds which are symmetrically arranged, covered with minute granules and surrounded with dark purple line. Anterolateral border of carapace bordered with about 15 minute tubercles and more or less serrated; posterolateral border composed of three large teeth, two wide and one narrow lobes, the distance between second teeth of both sides forming the greatest breadth of carapace. Chelipeds heavy as usual; marginal crest of carpus cut into four teeth and arranged side by side with a tooth at proximal end of outer surface of palm; upper border of palm cut into six or seven teeth, distal ones of which become narrower and sharper. Distinctive tubercles of both fingers of right chela in Calappa well developed.