Sakai, 1937
The carapace is subcircular, or rather rhomboidal, the lateral angles of the branchial regions being somewhat laterally produced. The upper surface is very weakly convex and finely granulated under the lens but is almost smooth to the naked eye. The branchio-cardiac grooves are rather distinct, they become broader and shallower toward the posterior surface.
The front is as broad as the posterior border and is mesially grooved, the postfrontal surface is laterally depressed, thus the frontal surface is defined from the gastric region. The marginal rim of the carapace is beaded with microscopical granules. The hepatic facets are proportionally broad, as the pterygostomial regions are strongly swollen; they are posteriorly defined by a shallow depression from the branchial regions. The merus and exopodite of the external maxillipeds are distally granulated.
Chelipeds are evidently more than 2.5 times the length of the carapace in adult male. The arm is proximally constricted, its upper proximal surface, as well as its anterior border is covered with granules of various sizes. The wrist is granulated on the inner border; the palm is flattened and remarkably broadened distally, its inner surface is sparingly granulated. The immovable finger is shorter than the movable finger, which is barely a little shorter than the palm. Both fingers are longitudinally striped with carinae; the cutting edge of the immovable finger is armed with about ten teeth in the distal three fourths; while on the movable finger, the teeth are 13 or 14 in number, distributed on its whole extent. The ambulatory legs are all very slender, the posterior border of the merus is finely granulated; the dactylus is much longer than the propodus and is lanceolate in shape.
The abdomen in both sexes are as in Philyra platycheira.
This species is akin to Philyra syndactyla Ortmann, from which it can readily be distinguished by its smaller size, and by the more uneven upper surface of carapace. The palm is much more broadened distally, and is longer than the fingers. It is also akin to Philyra granigera Nobili from the Red Sea, but the new species has the movable finger not curved at the base as in that species. From Philyra adamsii Bell the new species is distinguished by the absence of median rostral tooth; the carapace of Philyra adamsii is posteriorly covered with granules, but in the present species, the upper surface is merely punctulated. (Sakai, 1937: 157)
Type locality: Shimoda, Japan, 30-50 m.
Range: Japan - Shimoda (Sakai, 1937a, 1976), Amakusa (Miyake et al., 1962); 30-50 m.