Abstract
This paper outlines a brief overview of the genus taxonomy of megascolecid earthworms in Japan. First, the historical
background of the genus taxonomic classification for the Asian pheretimoid earthworms is outlined according to the classification proposed by Sims and Easton (1972), along with a reference to the introduction of the particular classification in Japan. Next, the validity of the current genera of the group and the genus Metaphire Sims & Easton, 1972 are discussed, indicating that the validity of the current classification could be questionable in several points, and that genus Metaphire should be integrated into the genus Amynthas Kinberg, 1867 as mentioned by Zhang et al. (2016). A summary for novice learners has also been provided, including characteristics and identification of the currently valid genera, distribution and species diversity characteristics, and taxonomic traits of the species. Sims, R. W. and Easton, E. G., 1972. Biol. J. Linn. Soc., 4: 169–268; Zhang, L. et al., 2016. Sci. Rep., 6: 20096.
