To determine the valid name of the Borneo eel that has a plain body coloration and is endemic to Borneo Island, three type specimens of Anguilla borneensis Popta, 1924, Anguilla malgumora Kaup, 1856, and Muraena malgumora Bleeker, 1864 were examined and compared to the morphological characters of the 42 longfin eels from Borneo, A. anguilla (44), A. japonica (37), and A. dieffenbachii (14), all of which have the same external appearance of a long dorsal fin and plain body color, except for M. malgumora Bleeker, 1864, which has a short dorsal fin. Discriminant analysis using 13 proportional characters and the relationship among three vertebral characters clearly showed that the type specimen of Anguilla malgumora Kaup, 1856 upon which Bauchot et al. (1993) proposed the revival of that name to replace A. borneensis Popta, 1924, based on priority without examining the specimen, was in fact clearly not a specimen of the Borneo eel as was concluded by Ege (1939). Therefore A. borneensis Popta, 1924 is the valid name for the Borneo eel, and A. malgumora Kaup, 1856 appears to be a junior synonym of A. anguilla (Linnaeus, 1758), and M. malgumora Bleeker is a junior synonym of A. bicolor McClelland, 1844.