Identification of two new species of Mecistocephalus (Chilopoda, Geophilomorpha, Mecistocephalidae) from southern China and the re-description of Mecistocephalus smithii Pocock, 1895

<i>Mecistocephalus</i> Newport, 1843 is the most diverse genus in the family Mecistocephalidae; however, only two species have been recorded in mainland China to date. Therefore, taxonomic research on Chinese <i>Mecistocephalus</i> needs further research. In this study, the species diversity of <i>Mecistocephalus</i> in southern China was investigated using the mitochondrial marker COI integrated with morphological evidence. Species delimitation using Automatic Barcode Gap Discovery, Poisson Tree Processes, and phylogenetic and morphological analyses revealed ten species, including two newly described species, <i>M.chuensis</i> Jiang & You, <b>sp. nov.</b> and <i>M.huangi</i> Jiang & You, <b>sp. nov.</b> Furthermore, based on newly collected specimens, the presence of the little-known species <i>M.smithii</i> Pocock, 1895 was confirmed in China and thoroughly re-described.