Abstract
Psilorhynchoides arunachalensis, new species is described from the Brahmaputra basin in Arunachal Pradesh of Northeastern India. It belongs to the Psilorhynchus homaloptera and P. pseudecheneis group, for which genus Psilorhynchoides was erected by Yazdani et al. (1990) because of their morphological and osteological distinctiveness from Psilorhynchus. The new species is differentiated by the following characters: eight or nine simple pectoral fin rays; more number of vertebrae 43-45 and an intermediate number of lateral line scales 42-44 between the valid species P. homaloptera and P. pseudecheneis (38-41 and 48-50 respectively).