(Serène, 1969)
The general aspect of the carapace resembles that of the typical Xantho reynaudii, but the tubercles found on the anterior half of carapace are more or less worn out. Antero-lateral borders are extremely arcuated, the four lobes behind the external orbital angle being rounded and not forming angular teeth as in the typical species. The tubercles upon the posterior half of carapace are, as well as those on the postero-lateral borders, somewhat more prominent and obtusely pointed. The frontal lobes are smooth and their free margin entire and sinuate but not appreciably produced near the median notch as in the typical species. The granules on the under surface of carapace and sternum are much finer than those of the other part of the body; the granules on the external maxillipeds are entirely worn out.
The chelipeds are symmetrical, the palm has its inner surface flat and smooth, the upper margin sharply crested, while the outer surface is covered with rather flat tubercles; the wrist and palm are dorsally and externally covered with sharp fine granules, the former has an obtuse tooth and an accessory denticle near the inner angle, the latter has an obtusely crested superior border, which is divided into four or five obtuse teeth. The granules on the outer and under surfaces of palm are arranged in longitudinal series. The movable finger is weakly crested in proximal half of the superior border; both fingers are not at all pigmented, and their prehensile edges armed with five to six obtuse teeth.
The anterior three pairs of the ambulatory legs have the carpus and propodus faintly granulated on the dorsal surface, in the last pair, however, the merus, carpus, and propodus are granular. In all pairs, the merus is crested along the anterior border and bicarinate along the posterior border; in the last pair, the proximal crest of the posterior border forms a wing-like plate; the anterior border of carpus and both borders of propodus are also sharply crested. Dactyli are all styliform, regularly decreasing in length from first to last, each anterior and posterior margin being furnished with two longitudinal rows of hairs respectively. (T. Sakai, 1939: 461)
Type locality: Chi-lung, Taiwan.
Range: Japan - Kii Minabe and Tosa Bay (Sakai, 1976a); Taiwan - Chi-lung (Serène, 1969, Guinot, 1979b); China - Guangdong (Dai & Yang, 1991); South China Sea (Serène & Lohavanijaya, 1973).