Two new earthworm species of the genus Amynthas (Oligochaeta: Megascolecidae) from central Taiwan, with comments on some recent species assignments in Amynthas and Metaphire.

This study describes two new species of earthworms belonging to the genus Amynthas (Oligochaeta: Megascolecidae) from central Taiwan. They are named Amynthas luridus sp. nov. and Amynthas ruiyenensis sp. nov. Both species are octothecal with the former found at elevations of 1500-2300 m and the latter at an elevation of 2200 m from the Central Mountain Range. In addition, DNA barcodes are made available for the first time for the following species: Amynthas catenus Tsai et al., 2001, Amynthas exiguus aquilonius Tsai et al., 2001, Amynthas proasacceus Tsai et al., 2001, Amynthas hohuanmontis Tsai et al., 2002, Amynthas tessellatus Shen et al., 2002, Amynthas fenestrus Shen et al., 2003, Amynthas tantulus Shen et al., 2003, and Amynthas uvaglandularis Shen et al., 2003. Furthermore, Amynthas exiguus ssp. aquilonius Tsai et al., 2001 distributed at elevations of 2200-3000 m in the Central Mountain Range is elevated to species level, as A. aquilonius Tsai et al., 2001. The highest altitude record so far for the exotic Eukerria saltensis (Beddard, 1895) in Taiwan, 2200 m above sea level, is documented. Moreover, some recent assignments of species to Amynthas and Metaphire and synonymies of names are critically discussed. It is argued that idiosyncratic genus concepts, inadequate species comparisons, and unexplained synonymies should be avoided. A hitherto undetected and possibly monophyletic species group of mainly Korean Amynthas species in the A. tokioensis-group is indicated, characterized by numerous genital papillae around each spermathecal pore and male porophore, large ampullae, long diverticula, large prostate glands, and manicate intestinal caeca. The names A. bimaculata, A. silvatica and A. surcata (Ishizuka, 1999), as well as A. odaesanensis, A. righii, A. fasciiformis, and A. sanchongensis Hong James, 2001, previously declared as junior synonyms of A. tappensis (Ohfuchi, 1935), are revalidated.