Revision of the species group of the millipede genus Gervais, 1847, with descriptions of five new species from China (Diplopoda, Spirostreptida, Cambalopsidae).

The -group of is re-assessed and its Chinese component species are presently divided between the following two newly-circumscribed species groups, i.e. the - and the -group. The two can be differentiated, based on the diagnostic characters of the first pair of legs in the male. In addition, metatergal crests being complete and the carinotaxy formula on the collum being I-III+P+M are only characteristic of the -group. A molecular phylogeny of the genus, based on DNA sequencing of four gene fragments of four genes, allows for to be recovered as a monophyletic group, the phylogenetic relationship being ((Clade A, Clade B), Clade C). Molecular evidence is fully congruent with the morphological one. In addition, based on barcoding data, interspecific p-distances between species amount to 11.2-24.9%, vs. 0-8.2% for intraspecific p-distances. Five new species of , all cavernicolous, are described from China: Zhao & Liu, , Zhao & Liu, (both from Guangdong Province), Zhao & Liu, , Zhao & Liu, and Zhao & Liu, (all three from Guangxi Zhuang Autonomous Region). The known Chinese species of the -group appear to mainly be confined to the South China region.