In general this species is close to I. liodactylus Rathbun, but differenciated from it in the shape of the frontorbital region, the marginal spines of the carapace and the chelipeds. The granules are much coarser on the carapace. Frontorbital region well developed and directed obliquely upward, tip of each tooth being sharply angulated. Of three tubercles on posterior margin of carapace the median one strongly developed, rather flattened and extended beckward with its tip curved dorsally; each lateral tooth lobular and blunt at apex. Chelipeds slender; merus cylindrical and covered with round granules, tapering distally; palm also cylindrical, smooth, and about proximal one-third bulged and then rapidly tapering; fingers about half as long as palm.
Distribution:
Weat Atlantic from North Carolina through the coasts of Florida and Venezuela to Brazil, 10-35 m deep.