(Miers, 1886)
The carapace is slightly transverse, rather flat, with the sutures defining the various regions of the dorsal surface very distinct; the body is everywhere very distinctly and evenly granulated; the granules of the dorsal surface somewhat larger and less crowded than those of the inferior surface of the body. The antero-lateral margins of the carapace are somewhat shorter than the postero-lateral margins. The front is rather broad and but little prominent; its anterior margin is obscurely sulcated longitudinally and divided into two lobes by a slight median notch; the antero-lateral margins of the carapace bear only three triangular teeth, the first of which is placed at some distance from the exterior orbital angle, and the second rather nearer to the third than to the first tooth. The infraorbital prolongations of the antero-lateral margins, characteristic of the type of the genus Medaeus are here indicated merely by a very obscure line of granules, reaching from the first of the antero-lateral teeth to a point just beneath the exterior angle of the orbit. The orbits are oval, with a moderately prominent inner suborbital lobe and a slightly indicated notch at the outer angle, and another in the middle of the superior margin. The post-abdomen in the male is five-jointed (as in the type), with the third to the fifth joints coalescent, and the terminal joint transverse and semicircularly rounded. The antenna and maxillipeds present nothing remarkable; the basal antennal joint reaches to the infero-lateral frontal process, and third maxilliped exopod attains the antero-external angle of the distally truncated merus. P1 moderately robust for so small a species, the joints granulated much more distinctly on the outer than on the inner surface; the merus has a series of larger granules on its upper margin, and the carpus a spiniform tooth on its inner surface; the palm of the larger cheliped is much more distinctly granulated on and near the upper margin and at the base than elsewhere; the fingers are regularly denticulated on the inner margins and acute at the tips, and the dactylus sulcated above. The smaller cheliped is externally more strongly granulated, with relatively longer and more slender fingers; P2-5 denticulated on their upper margins, and the dactyli styliform, straight. Colour in spirit yellowish-brown; the fingers of the chelipeds are chocolate-brown, the colouration not extending over the palmar surface. (Miers, 1886: 117)
Type locality: Twofold Bay, Australia, 270 m.
Range: Christmas Island; Japan; Philippines - north of Lubang Island (Serène & Vadon, 1981); Australia - Twofold Bay (Miers, 1886); New Caledonia (Davie, 1997); Loyalty Islands (Davie, 1997); Waterwitch Bank (Davie, 1997); Wallis Island (Davie, 1997); 80-527 m.