Sakai, 1969
A rather small species; its nearest relative is probably P. bicornis from the Sea of Java, from which it may be distinguished by the peculiar lobe on the outer border of the propodus of the cheliped and by the different arrangement of the teeth and processes of the carapace.
The carapace is in the form of a rounded triangle, the dorsal surface being smooth. The gastric and cardiac regions are markedly convex and conical, each ending in a long process, of which the gastric is thick and very long, projecting obliquely backwards, while the cardiac is a little smaller and projecting upwards.
The front is rounded triangular in outline, the margin entire. On the antero-lateral borders, the hepatic portion is entire and rounded, completely merged with the external orbital angle; the branchial portion is set with six to seven teeth, which are triangular and confluent with each other at the base. The carapace is very slightly constricted behind the hepatic margin. There is an oblique and sparingly granulated ridge on each branchial region running from the last antero-lateral tooth toward the middle portion of the carapace. The postero-lateral borders are almost straight and marked with a few tubercles.
The chelipeds are strikingly asymmetrical. The left is very small, each segment is slender and the fingers cross each other strikingly in the distal half. The right cheliped is robust, the merus very broad and its anterior and posterior borders cut into five or six cristate teeth, the carpus is thin and small, while the propodus is again robust, its outer border bears a very broad and round lobe at the proximal half, its interior border is finely serrated. The immovable finger has three obtuse teeth near the middle of the prehensile edge.
The ambulatory legs are very thin and the anterior and posterior borders of each segment are marked with tiny denticles. (Sakai, 1976)
Type locality: Kii Minabe, Japan.
Range: Japan - only Kii Minabe (Sakai, 1976a).