The millipede genus Pycnotropis CARL, 1914 is shown to be represented in the floodplains near Manaus by a single, highly variable and obviously eurytopic species which occurs also in secondary upland forest: P. epiclysmus HOFFMAN, 1996 (Polydesmida: Platyrhacidae). To facilitate recognition, especially so vis-a-vis a number of its nominal and by far more poorly known congeners, some of which are possibly its senior synonyms, the variation range of this species is briefly outlined. In addition, a direct, side-by- side re-examination of topotypes of Epinannolene arborea HOFFMAN, 1984 (Spirostreptida: Pseudonannolenidae) and the holotype of Pseudonannolene exilio BRÖLEMANN, 1904, all from Manaus, results in a new formal synonymy and combination: Epinannolene exilio (BRÖLEMANN. 1904), syn. n., comb. n