The pea crab genus Arcotheres Manning, 1993 (Crustacea: Brachyura: Pinnotheridae) from Singapore and Peninsular Malaysia, with a reappraisal of diagnostic characters and descriptions of two new genera Author Ng, Peter K. L. Author Ahyong, Shane T. text Raffles Bulletin of Zoology 2022 2022-04-01 70 134 248 journal article 10.26107/RBZ-2022-0009 2345-7600 7174234 BE6164AE-1C24-4E01-8B7B-D80764F147B3 Magnotheres , new genus Type species. Pinnotheres globosum Hombron & Jacquinot, 1846 , by present designation. Diagnosis. Carapace dorsal surface smooth, without obvious gastric grooves. MXP3 dactylus slender, inserted near or slightly proximal to ventral midlength of propodus, variable length; propodus spatuliform, about 3.0 times longer than wide; inner margin of widest part of ischiomerus rounded to angular; exopod relatively slender with proximal part of exopod not especially wide. Female P 4 slightly asymmetrical, with merus on left or right side slightly longer; dactyli of P2 and P3 subequal, weakly curved, longer than half propodus length, P4 dactylus similar in shape but slightly longer than P2 and P3 dactyli; P5 dactylus elongate, weakly falciform, with 2 rows of distoflexor spinules. Male pleon relatively