(Sakai, 1961)
The carapace of the new species is more typically pyriform than in Eurynome stimpsoni, the constriction behind the postorbital portion being stronger and the posterior half of the carapace more swollen and rounded in outline. The rostral horns are short, divergent at an angle of about 45°, each horn slender and subcylindrical, not at all flattened as in E. stimpsoni, and their outer borders are finely serrated. The supraorbital eave is also sharply serrated, its posterior end forming a small but acuminate spine; the intercalated spine is also sharp and basally broadened, the postorbital spine is somewhat arched on its inner and outer borders and its tip is directing obliquely forward. The infraorbital spine is also sharp and of good size.
The dorsal surface of the carapace shows scattered sharp spinules and bears mushroom-like expansions of various sizes, of which three are in the median line and the others are disposed symmetrically on either side of the carapace. The surface of these expansions is sharply spinulated. Of the three median expansions, the first or the gastric one is small; the second or the cardiac one is very large and ovoid in outline and its centre drawn up into a conical process with a sharply pointed tip; the last one is on the posterior border, its middle portion is small and subglobular, each lateral portion is narrow and extends obliquely forwards along the postero-lateral margin.
There are two spines side by side in front of the gastric expansion, and one small expansion in the rear of the orbital region. The hepatic tubercle is rather small and is laterally projecting. On the branchial region there are three expansions in a group, the anterior one of which is small and is antero-internally pointed, the lateral one is oblong and is on the lateral border and the posterior one is sharp and postero-laterally pointed. The remainder of the dorsal surface of the carapace shows scattered granules of different sizes.
The ventral surface of the carapace is also spinulated; there is a small accessory spine beneath the hepatic expansion. The outer maxilliped has the ischium and merus spinulated, the former has about six spines on the inner border, the latter is produced at the antero-external angle. The antero-external angle of the buccal frame also projects into a spinulated process.
The chelipeds of the male are very long, being about twice the total length of the carapace; the merus is stout and as long as the carapace and is covered with sharp spinules, of which five or six on each anterior and posterior border are of good size and are placed at rather regular intervals. The carpus and propodus are much more slender, the latter being about twice as long as the former; the outer border of both segments is sharply spinulated. Merus, carpus and propodus of ambulatory legs are uniformly covered with sharp spinules; the dactylus is slender and very sharply pointed at the tip. (Sakai, 1961)
Type locality: Amadaiba, off Hayama, Sagami Bay, Japan, 75 m.
Range: Japan - Sagami Bay (Sakai, 1961, 1965, 1976), Tosa Bay (Sakai, 1976a), Ogasawara-shoto (Takeda, 1977a); East China Sea (Takeda & Miyake, 1972c); Indonesia - Selat Sape, Madura Bay, Molo Strait, Haruku Island, Kepulauan Aru and Kepulauan Kai (Griffin & Tranter, 1986a); Western Australia (Griffin, 1970c); 65-130 m.