Telphusa pealiana Wood-Mason, 1871:204 Potamon pealianum Telphusa pealiana Wood-Mason, 1871 Potamon ( Potamon ) pealianus Telphusa pealiana Wood-Mason, 1871 Potamon ( Potamon ) pealianum antennarium Alcock, 1909: 245 Potamon ( Potamon ) pealianum Potamiscus pealianus Brandis, 2000: 72 Telphusa pealiana Wood-Mason, 1871 Potamiscus pealianus 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) Mitra, Santanu Monica, Thingbaijiam Waikhom, Mema Devi Zootaxa 2020 2020-08-28 4838 4 475 490 84GQB (Wood-Mason, 1871) Mitra & Monica & Waikhom 2020 Wood-Mason 1871 [151,687,1538,1565] Malacostraca Potamidae Badistemon Animalia Decapoda 8 483 Arthropoda species pealianus comb. nov.  ( Fig. 7A–C, 8D–F)    Telphusa pealiana Wood-Mason, 1871:204, pl. 14, fig.7–11.   Potamon pealianum—De Man, 1898: 410, pl. 5, fig. 7 [not  Telphusa pealiana Wood-Mason, 1871].   Potamon( Potamon) pealianus—Rathbun, 1904:310. [not  Telphusa pealiana Wood-Mason, 1871]     Potamon( Potamon) pealianum antennarium Alcock, 1909: 245.   Potamon( Potamon) pealianum—Alcock, 2010:38, pl.10, fig. 44.    Potamiscus pealianus— Bott, 1970:161, pl. 38, fig. 33; pl. 47, fig. 29.     Potamiscus pealianus—  Brandis, 2000: 72, pl. 7 a–c. [not  Telphusa pealiana Wood-Mason, 1871]   Potamiscus pealianus—Ng et al., 2008: 165 [list only]   Remarks. Wood-Mason (1871)described  Telphusa pealiana(1871: 204, pl. XIV. Fig. 7–11) based on a single male specimen (cw 41mm, cl 32 mm), collected by S. E. Peal, from Sibsagar, Assam. Alcock (1910)classified some species of  Potamiscus( sensu. lato), namely  P. pealianum;  P. paelianum var. antennarium;  P. tudrgidulumand  P. tumidum; in a separate ‘group’ named as “  pealianum”- group, in having some common characters i.e., grooves and regions distinct, cervical groove cuts the post orbital cristae at the same point, carapace deep, and convex longitudinally. Alcock (1910: 40, fig.44) examined a good series of collections, in ZSI, Kolkata, collected by S.E. Peal, from Sivasagar, Assam; but unfortunately did not referred to the type specimens in those collections. Later, Bott (1970)synonymised  Potamon( Potamon) pealianum var. antennarium, Alcock, 1909, with  P. pealianusand transferred this species to  Potamiscus Alcock, 1909; by designating a male lectotype(cw 41.6 mm, cl 35.2 mm) and a female paralectotype(ZSI-C6413/3), from the collections of S. E. Peal (collected from Sibsagar, Assam). While examining all the  Potamon (Potamon) pealianum, identified by Alcock (1910), we found out that the male specimen (cw 41.6 mm, cl 35.2 mm, ch 18.8 mm, fw 10.4 mm)(ZSI-C 6958/3) is agrees well with the original descriptions of Wood-Mason (1871), which is therefore the holotype; simultaneously all the other specimens, collected by S.E. Peal from Sivasagar, Assam, should be considered as paratypes. Bott’s (1970)decision, regarding subsequent designation of lectotypeand paralectotype, however, is invalid.  Potamiscus pealianuss.latois easily distinguished from  Potamiscuss. stricto[type species:  Potamon (Potamiscus) annandali Alcock, 1909], by its more broad, squarish carapace ( Alcock, 1910: pl 10. fig. 44; Fig. 7 A) (vs. relatively narrow carapace in  Potamiscus; Alcock, 1910: pl. 3. Fig. 10; Naruse et al., 2018: fig. 28 a; Yeo & Ng, 2007: fig. 11 a); weakly developed and distinctly rugose postorbital cristae ( Alcock, 1910: pl 10. fig. 44; Fig. 7 A) (vs. well developed and distinctly non-rugose, cristate postorbital cristae in  Potamiscus; Alcock, 1910: pl. 3. Fig. 10; Naruse et al., 2018: fig. 28 a; Yeo & Ng, 2007: fig. 11 a); antennular fossae relatively broad, sub triangular ( Fig. 7B) (vs. narrow, slit-like antennular fossae; Naruse et al., 2018: fig. 28 b; Yeo & Ng, 2007: fig. 11 b); relatively longer and slender propodus and dactylus of ambulatory legs, lined with short, stiff setae ( Alcock, 1910: pl 10. fig. 44) (vs. relatively shorter propodus and dactylus, glabrous ambulatory legs in  Potamiscus; Alcock, 1910: pl. 3. Fig. 10; Naruse et al., 2018: fig. 28 a); and the exopod of third maxilliped with well-developed flagellum (vs. flagellum absent or vestigial in third maxilliped exopod) ( Naruse et al. 2018).   FIGURE 6.  Badistemon turgidulum( Alcock, 1909), lectotype male (ZSI-C6952/2) (cw 28.7 mm × cl 23.5 mm): A. dorsal view of carapace; B. frontal view of cephalothorax; C. male thoracic sternum and pleon.   FIGURE 7.  Badistemon pealianus( Wood-Mason, 1871),  comb. nov.holotype male (ZSI-C 6958/3) (cw 41.6 mm × cl 35.2 mm): A. dorsal view of carapace; B. frontal view of cephalothorax; C. male thoracic sternum and pleon.   FIGURE 8.  Badistemon turgidulum( Alcock, 1909), lectotype male (ZSI-C6952/2) (cw 28.7 mm × cl 23.5 mm): A. dorsal view of left G1, B. ventral view of left G1, C. dorsal view right G2;  Badistemon pealianus( Wood-Mason, 1871)  comb. nov., holotype male (ZSI-C 6958/3) (cw 41.6 mm × cl 35.2 mm): D. dorsal view of left G1, E. ventral view of left G1, F. dorsal view of right G2. Scale bar=1 mm.   FIGURE 9.Thoracic sternites showing vulvae, A.  Badistemon turgidulum( Alcock, 1909), Paralectotype female (ZSI-C6952/2) (cw 30.2 mm × cl 24 mm); B.  B. pealianus( Wood-Mason, 1871)  comb. nov.Paratype female (ZSI-C6413/3) (cw 37.2 mm × cl 28.9 mm)   FIGURE 10.  Badistemon fulvum  n.sp., holotype male (ZSI-C7543/2) (cw 48.7 mm × cl 39.5 mm): A, live coloration; B, habitat in the type locality, Bungkucha stream; C, burrow We examined the old collections of S.E. Peal from Sibsagar, Assam and Kakhyen hills of Myanmar(collected by J. Anderson) along with the holotypeand a recent collections from Mizoram ( Mitra, 2017), and found that  P. pealianusis congeneric with  B. turgidulumand  B. fulvum  sp. nov.All these species has same squarish-looking, relatively high and longitudinally convex carapace; exopod of third maxilliped with well-developed flagellum, not exceeding the merus width; male sternopleonal cavity reaches imaginary line of posterior border of the cheliped coxae; G1 relatively long, subcylindrical, with short and low dorsal flap. As such we herein re-assign  Potamiscus pealianus( Wood-Mason, 1871)as  Badistemon pealianus  n. comb.The genus  Badistemonnow consists of three species, a key to the species are provided here for easy identification.