Monotypical representative of the genus, and characteristic in having enormously long fingers of male chelae. General shape of carapace similar to that of Portunus, with a strong lateral tubercle at each side; dorsal surface rather uneven, only with a weak linear ridge from each lateral tubercle, being uniformly covered with microscopical granules. Front with two small inner and two large outer teeth, being separated from each supraorbital tooth by a V-shaped notch. Anterolateral border of carapace armed with eight sharp teeth in front of lateral tubercle. Chelipeds slender; fingers of male chelae about twice as long as palm, but those of female only slightly longer than palm, with tips curved outward. Both borders of merus of natatory leg each with a terminal spine.
Distribution:
Previously known only from the West Indies, 10-15 m deep.