Takeda, 1974
Carapace transversely ovate or rather quadrate. Dorsal surface evenly convex in both directions, with the regions moderately marked, furnished with some tufts of hairs, notably along frontal margin. Antero-lateral margins with three stout teeth behind exorbital angles, the last distinctly smaller. Front well developed, divided into truncate lobes by a median deep sinus. Antennules folding transversely into the fossae. Basal antennal article not reached to ventral prolongation of front; its flagellum usually of considerable length. Endostomial ridges developed only posteriorly. Chelipeds unequal and usually armed with spines or nodules. Male abdomen narrow. G1 pilumnid, but its beak ill-developed. G2 sigmoid. (Guinot 1998)
Carapace transversely ovate or rather quadrate, its dorsal surface evenly convex in both directions and more or less separated into regions, being provided with a transverse row of hairs along frontal margin with some prominent tufts of hairs on protogastric and antero-lateral regions. Front well developed with a median deep sinus and rather distinctly separated from supraorbital angle. Infraorbital border with two deep depressions and a strong inner angle. Antennal basal segment not reached to ventral prolongation of front, its flagellum being usually of considerable length. Palatal ridges developed only posteriorly, not extending forward to anterior boundary of buccal cavern. Antero-lateral border of carapace with three stout behind external orbital angle, last tooth distinctly smaller than preceedings and often spine-tipped. Chelipeds unequal and usually armed with spines or nodules. Male abdomen narrow with seven segments. Male first pleopod rather Pilumnus-type, but its beak ill-developed. (Takeda, 1974)
Type species: Medaeus rouxi Balss, 1935.
Gender masculine.
Species treated:
Nanopilumnus coralliophilus (Takeda & Miyake, 1969)
Nanopilumnus hondai (Takeda & Miyake, 1969)
Nanopilumnus rouxi (Balss, 1935)