(Rathbun, 1909)
Carapace rounded-trapezoidal, its dorsal surface flattened, whole surface densely but microscopically granular; lateral borders slightly divergent posteriorly, without any trace of lobules near the posterior angle; frontal margin clearly bilobed, lobes separated by a v-shaped median incision. Chelipeds slightly heterochelous, smooth and glabrous, upper margins of merus, carpus, palm and dactyl bear rows of setae; fingers of chelae slightly shorter than palm. Second to fourth pereiopods with numerous setae, especially at the upper and lower margins, much sparser on anterior and posterior faces. (Türkay 1995)
Type locality: off Koh Kut, Gulf of Thailand.
Range: Japan - Mizuho, coast of Shimabara Peninsula (Sakai, 1976a), Amakusa (Yamaguchi et al., 1976), Nanki Shirahama (Miyake, 1983), Shimabara and Ariake Sea (Muraoka, 1998), Tosa Bay, Hakata Bay; Korea - Inch'on (Kamita, 1941); Gulf of Thailand (Rathbun, 1909); muddy flats.