Key to species of Iridopagurus from Brazil

1. Left cheliped with dorsodistal margin of merus with strong spine............................................ I. iris

– Left cheliped with dorsodistal margin of merus unarmed...................................................... 2

2. Palm of right cheliped oval, dorsal face with color pattern reticulated. Ventral margin of dactyls of p2 and p3 with 3–8 corneous spinules................................................................................... I. reticulatus

– Palm of right cheliped sub-rectangular, dorsal face of fingers with darker transverse stripe. Ventral margin of dactyls of p2 and p3 with 8–12 corneous spinules................................................................... I. violaceus