A new species of Eliurus, E. danieli Nesomyidae: Nesomyinae, is described from the Parc National de l'Isalo in south-central Madagascar. Although geographically intermediate to eastern and western forms, diagnostic traits convincingly relate the new species to E. majori and E. penicillatus, forms distributed primarily in eastern humid forest; it is morphometrically most similar to E. penicillatus. In view of the increase in number of Eliurus species 11 now described, discussion is devoted to emerging species associations 5 are identified and to taxonomic and distributional problems introduced by the accumulation of larger series and new localities over the past decade.