Carapace hexagonal, 1.44 times as broad as long, smooth, moderately convex in both directions; epibranchial ridge starting at last antero-lateral tooth and reaching across branchial regions; front with a deep median U-shaped incision, the two lobes thus separated are each divided into two by a shallower indentation; antero-lateral borders with 7 sharp teeth, first one more lobular with subtruncate outer border, fifth to seventh with black horny tips, seventh largest, directed obliquely outwards. Chelipeds heterochelous and smooth; merus with 3 sharp spines with dark tips on anterior border, posterior border smooth; carpus with similar spines at its inner corner and median part of distal margin. (Türkay 1995)
Type locality: Shimoji-shima, west of Miyako-jima, Ryukyu-shoto, Japan.
Range: Japan - Ie-jima, Irabu-jima and Shimoji-shima (Takeda, 1993).