Rathbun, 1909
Carapace quadrangular, rounded anteriorly. Dorsal surface well calcified. Lateral margins parallel; antero-lateral margins forming a regular curve with the anterior margin and continuous with the postero-lateral margins. Front very narrow. Orbits long and transverse, occupying the whole anterior border and prolonging in the antero-lateral margins of the carapace. Eyestalks very long, deeply located in the orbits, swollen in their proximal part then tapering. Eyes reduced to a speck of pigment but cornea elongate. Antennules enormously thickened, not folded into the fossae and concealed in a dorsal view, their stout basal article entirely filling the fossae. Buccal cavern anteriorly narrowed, its outer borders arcuate. Third maxillipeds with the merus anteriorly narrowed; palp short, articulated at the summit of the merus. Chelipeds subequal, shorter than the ambulatory legs. Ambulatory legs rather long and slender, with spinose borders. Male abdomen with segments 3-5 fused. (Guinot 1998)
Species treated:
Megaesthesius yokoyai Sakai, 1939