The millipede tribe Leptoiulini in the Caucasus, with notes on its generic classification (Diplopoda: Julida:...

The generic classification of the Palaearctic tribe Leptoiulini is revised, with 11 genera being recognized. The main differences between the genera, all presented in a tabular form, lie in the structure of the 2nd and 7th leg-pairs of the male, coupled with gonopodal conformations: the presence/absence and the degree of development of flagella on the promeres, and of the phylacum and velum on the opisthomeres. Based on abundant new material, only three genera and seven species of Leptoiulini, all keyed, mapped and properly illustrated, are shown to occur in the Caucasus: Chatoleptophyllum flexum Golovatch, 1979, Kubaniulus gracilis Lohmander, 1936, K. lativelatus sp. nov., Leptoiulus hastatus Lohmander, 1932 (= L. disparatus Lohmander, 1936, syn. n.), L. tanymorphus (Attems, 1901), L. meskhii sp. nov., and L. gonopodialis sp. nov. All species are endemic or subendemic to the region, while Kubaniulus Lohmander, 1936 represents the only genus in the tribe which is restricted to the Caucasus, in particular, the western and central parts of the Caucasus Major. The distributions are mainly allopatric, but a few pairs of species are para- or even sympatric.