Rathbun, 1907
Very closely related to Pachygrapsus plicatus but the carapace is relatively longer and almost quadrangular, the lateral borders being parallel and not at all convergent posteriorly as in plicatus. The ambulatory legs are somewhat slenderer, i.e., the merus is just twice as long as broad, the posterior distal border of this segment is armed with two or three spinules, one of which is of good size. (T. Sakai, 1939: 658)
Type locality: Fakarava, Tuamotu Archipelago.
Range: Japan - Northern Daito-jima (Sakai, 1939), Yoron-jima, Ishigaki-jima and Northern Daito-jima (Sakai, 1976a); Taiwan; Tuamotu Archipelago - Fakarava (Rathbun, 1907).