A new species of freshwater crab of the genus Badistemon Yeo & Ng, 2007 (Decapoda: Brachyura: Potamidae: Potamiscinae) from Manipur State, India with the reassignment of Potamiscus pealianus (Wood-mason, 1871) Author Mitra, Santanu Zoological Survey of India, Crustacea Division, F. P. S. Building, 27 JawharLal Nehru Road, Kolkata- 700016, West Bengal, India santanuzsi @ gmail. com; http: // orcid. org / 0000 - 0002 - 3247 - 9293 santanuzsi@gmail.com Author Monica, Thingbaijiam Department of Life science, Manipur University, Indo Myanmar Road, Canchipur, Imphal- 795003, Manipur, India Monica 19 th @ gmail. com; http: // orcid. org / 0000 - 0002 - 3037 - 9539 onica19th@gmail.com Author Waikhom, Mema Devi Department of Zoology, G. P. College, Imphal- 795001, Manipur, India text Zootaxa 2020 2020-08-28 4838 4 475 490 journal article 8630 10.11646/zootaxa.4838.4.2 0f83dc4d-1de7-447b-95fb-da7134fd0b2c 1175-5326 4405367 6778A39E-1625-4D6D-9DD2-5FFB2F02415C Key to the species of Badistemon Yeo & Ng, 2007 1. Suture between male thoracic sternites s3/s4 is prominent; sixth pleonal somite ca. 2.5 times wider than median length; telson elongated, distal end narrowing; G1 subterminal segment distal part relatively broad, slightly narrower than basal width, terminal segment relatively shorter, ca. 0.32 times than combined length of subterminal segment and flexible joint ( Fig. 6 A–C, 8 A–C; Yeo & Ng, 2007 : fig. 4. a–e)........................................ B. turgidulum ( Alcock, 1909 ) ( Myanmar ) - Male thoracic suture between s3/s4 is not prominent, represent as a small depression in lateral margin of sternites; sixth pleonal somite note more than ca. 2 times wider than median length; telson elongated, distal end narrowing; G1 subterminal segment distal part neck-like, abruptly narrower than basal width, terminal segment relatively long, more than ca. 0.40 times than combined length of subterminal segment and flexible joint........................................................ 2 2. Cervical groove prominent, regions distinct ( Fig. 7A ), male telson as long as broad ( Fig. 7C ), G1 terminal segment sub-cylindrical, tip truncated ( Fig. 8 D–F; Wood–Mason, 1871 : pl. 14, fig.7)..... B. pealianus comb. nov. ( Assam & Mizoram , India ) - Cervical groove superficial, regions not distinct ( Fig. 2A ), male telson broader than long ( Fig. 2 C ), G1 terminal segment conical, tip pointed ( Fig. 4 A–D, 5A, B)............................................ B. fulvum sp. nov. ( Manipur , India )