MacLeay, 1838
Hooked hairs almost always wanting. Carapace rounded, longitudinally oval or triangular. Dorsal surface flat or depressed, very thin, not well calcified, usually divided by grooves more or less numerous, delineated and complete; always an external rim encircling the whole surface or nearly. Antero-lateral margins entire, or with 2-4 teeth, or more. Front forming an unilobed, bilobed or trilobate rostrum, but sometimes rostrum vestigial or absent; the rostrum being truncate, rounded or triangular. Orbits absent or incomplete. Eyes usually exposed, exceptionally absent. Antennules not folding or folding longitudinally in shallow fossae. Antennae very small; basal article fused with epistome, when present, but not with front. Third maxillipeds pediform, subpediform or operculiform. Chelipeds not specially mobile, unequal, generally short and robust; fingers not bent at an angle to palm. Ambulatory legs short or elongate; dactyli with or without subterminal teeth. Male and female abdomens often with several segments fused, at least always with sixth segment and telson fused to form a pleotelson; sometimes presence of mobile intercalated plates, resembling uropods. Female abdomen sometimes very enlarged, forming to form a remarkable egg brood chamber. Female openings sternal. Male openings coxo-sternal. G2 short. (Guinot 1998)
Genera treated:
genus Elamena H. Milne Edwards, 1837
genus Halicarcinus White, 1846
genus Trigonoplax H. Milne Edwards, 1853