A new species of Ribautia Brolemann, 1909 (Chilopoda: Geophilomorpha: Geophilidae) from Peruvian Amazonia, with a key to the Neotropical species of the genus with coxal organs grouped in clusters

Ribautia williamsi sp. nov., a new dwarf geophilomorph centipede from the Lower Urubamba Region, Peruvian Amazonia, is described and illustrated based on the holotype female. The new species is characterized by having the coxal organs grouped in clusters (three of these in each coxopleuron of the ultimate leg-bearing segment) and ventral pore-fields present along all the body; these two combined traits being shared by five other Neotropical species currently included in the genus Ribautia Br lemann, 1909, i.e. R. centralis (Silvestri, 1907) (from Colombia and Brazil), R. difficilis Pereira, Minelli & Barbieri, 1995 (from Brazil), R. montana Kraus, 1954 (from Peru), R. peruana (Verhoeff, 1941) (from Peru), and R. titicacae (Turk, 1955) (from Peru). The new taxon is differentiated from the aforementioned species by the low number of leg-bearing segments and small body length; it is included in a key which will enable the identification of all known Neotropical members having coxal organs grouped in clusters. R. williamsi sp. nov. is the 14th species of Ribautia recorded from Peru. http://zoobank.org/urn:lsid:zoobank.org:pub:D9FA5FAF-7652-4A5B-AC09-8783F05A694D