Carapace distinctly depressed and roughly triangular in its outline; dorsal surface thickly covered with prominent granules and divided into convex regions by narrow and deep furrows; a tranverse furrow from posterior part of hepatic margin toward anterolateral angle of mesogastric region changed its direction longitudinally and united with a transverse furrow separating posterior part from main part of branchial region; cardiac region surrounded by furrows which form one of meshes; in some males a small tubercle at posterolateral part of posterior branchial region. Front with a triangular lobe in dorsal view, its tip being obtuse. External orbital angle tuberculated and directed forward. Chelipeds of fully developed male large. Ambulatory legs not stout, only first pair being fringed with soft hairs. A blunt tubercle at distal end of thoracic sternum in both sexes. A spine on first abdominal segment in male; in female abdomen terminal segment covers whole surface of thoracic sternum.