The springtails of the Netherlands: genus Ptenothrix, new to the Dutch fauna (Hexapoda: Entognatha: Collembola) This paper is the second in a series on the identification, distribution and ecology of springtails of the Netherlands. The genus Ptenothrix Börner, 1906 is described, with one new species present in the Netherlands, i.e. P. atra (Linnaeus, 1758). A second and third species, i.e. P. ciliata Stach, 1957 and P. setosa (Krausbauer, 1898) may be expected for the Dutch fauna, but have not been recorded yet. With a key, illustrated with drawings and photographs, specimens of Ptenothrix can be identified. For P. atra a distribution map, with a resolution of 5km squares is added. For each species an ecological profile is made. Ptenothrix atra is a stenotopic species, that can be found on river flood plains along the flood mark. Here it is found under basalt stones or concrete and under bark of fallen trees. It prefers wet to moist grasslands.