(Sakai, 1939)
The carapace is more strongly convex fore and aft than in Cycloxanthops lineatus, but almost flat from side to side. The regions of carapace are well demarcated and are covered with numerous minute pits, so that the dorsal surface appears as if it were eroded. The front markedly produced and deeply notched in the middle, the free edge of each lobe being strongly sinuate and distinctly separated from the preorbital angle, which is not at all dentiform. The upper orbital fissures are almost obliterated. The antero-lateral borders are elegantly divided into four broad lobes by three completely closed fissures, each lobe being sharply crested and of a low triangular shape, the apex being not developed into a tooth. The postero-lateral borders are markedly concave and are almost as long as the antero-lateral.
Chelipeds are asymmetrical, the arm is distally broadened and superiorly crested; wrist is irregular in shape, with two teeth at inner angle and the exposed surface wrinkled; palm has the upper border sharply crested, which is divided into irregular lobules; the outer surface thickly covered with rugae of irregular shape, some of the rugae being arranged in longitudinal rows. Merus of the ambulatory legs is sharply crested on anterior border, bicarinate on posterior border in distal half; carpus and propodus are rugose and their anterior border crested. Dactylus is very slender and fringed with velvety hairs. Abdomen much like that of Cycloxanthops lineatus. (T. Sakai, 1939: 455)
Type locality: Tatsugahama, Arita City, Kii Peninsula, Japan.
Range: Japan - Tatsugahama and Nanki Shirahama (Sakai, 1939), Kii Nagashima, Kii Minabe and Tosa Bay (Sakai, 1976a); Taiwan.