New genera are defined to accommodate three disjunct new chelodesmids endemic in Rondônia: Rondonaria n. gen., for R. schubarti n. sp.; Lithobiodesmus n. gen., for L. xenoporus n. sp., and Rhicnostethus n. gen., for the type species R. rondoni n. sp., and R. coriaceus (Schubart, 1947) n. comb., described from Mato Grosso. The tribal position of these new taxa cannot be confidently established on the basis of existing knowledge of the family; each is distinguished by one or more unusual anatomical characters.
Diplopoda; Polydesmida; Chelodesmidae; Brazil; Rôndonia
