New species of Korean Amynthas Kinberg, 1867 (Oligochaeta, Megascolecidae) with two pairs of spermathecae

New species of Korean Amynthas Kinberg, 1867 (Oligochaeta, Megascolecidae) with two pairs of spermathecae.-Twenty new species of the genus Amynthas are recorded from Korea: Amynthas piagolensis sp. n., Amynthas taebaekensis sp. n., Amynthas bubonis sp. n., Amynthas vicinus sp. n., Amynthas oviformis sp. n., Amynthas jindoensis sp. n., Amynthas jangbogoi sp. n., Amynthas deogyusanensis sp. n., Amynthas naejangensis sp. n., Amynthas draconis sp. n., Amynthas cuneatus sp. n., Amynthas yongshilensis sp. n., Amynthas alveolatus sp. n., Amynthas geomunensis sp. n., Amynthas eastoni sp. n., Amynthas boletiformis sp. n., Amynthas odaesanensis sp. n., Amynthas righii sp. n., Amynthas fasciiformis sp. n., Amynthas sanchongensis sp. n. Complete descriptions of the new species are provided, including illustrations of the male pore region and spermathecae.