The cave-dwelling polydesmid millipede Alocodesmus yporangae Schubart, 1946, from southeastern Brazil, is redescribed and its systematic position is discussed. A new monospecific genus Leodesmus Mauriès & Geoffroy is created [type species: Alocodesmus yporangae Schubart, 1946; Leodesmus yporangae n. comb.] and placed in the tribe Cornalatini (Chelodesmidae, Chelodesminae). Leodesmus can be distinguished from the other Cornalatini by a no monoliform habitus, and from the genus Obiricodesmus by the slide-shaped prefemoral process of the gonopods. Three morphological «forms» are formally recognized: «type», «acutus» and «alambari». Their geographical distributions are discussed according to a hypothesis of allopatric and peripatric processes of speciation.
Diplopoda, Brazil, biospeleology, speciation, taxonomy.