Abstract
A combination of morphological traits and DNA data (COI and 28S rRNA partial sequences) was used to study the genus Mongoloniscus Verhoeff, 1930 from China. Four new species are described: M.crenatus Jiang, Li & Huang, sp. nov., M.orientalis Jiang, Li & Huang, sp. nov., M.polyacanthum Jiang, Li & Huang, sp. nov., and M.parvus Jiang, Li & Huang, sp. nov. Following an in-depth examination of the Mongoloniscus species, Lucasioidesvannamei (Arcangeli, 1927), comb. nov. (from Mongoloniscus) is proposed, and M.chevronus Yang & An, 2021, syn. nov. is synonymized with Koreoniscusracovitzai (Arcangeli, 1927). A restrictive criterion for recognizing the genus Mongoloniscus is also provided in the present study.