Carapace longer than wide, uniformly covered with microscopical granules, and not so strongly convex. Front bidentate and inclined dorsally. Hepatic margin bluntly angulated; a shallow sinus between hepatic and branchial margins. Posterior border of carapace armed with three spiniform tubercles which are curved upward at their tips; median one at posterior border of intestinal region is the longest, and lateral two directed obliquely outward. Chelipeds slender, being about two and half times as long as carapace; merus cylindrical and covered with fine granules; fingers nearly as long as palm, cutting edges being armed each with a series of fine spinules and several equidistant larger ones; in fully developed male the proximal end of immovable finger convex downward, thus a rounded hiatus being left proximally between both fingers. Ambulatory legs slender.
Distribution:
West Florida, Haiti, Puerto Rico, Virgin Is., Trinidad and Suriname, 10-60 m deep.
Remarks:
The Pacific congener, I. hancocki Rathbun, is known from the Lower California to Columbia.