Abstract
A new species, Aneumastus yamdrokensis Liu & Xie, is described from Yamdrok Lake, collected during a survey of the freshwater diatom flora of Tibet, China. The valves of this new species are elliptical-lanceolate with rounded apices and have the features typical of the genus, including complex areolae. The morphology of A. yamdrokensis is documented with light and scanning electron microscopy, described in detail, and compared with the most similar taxa, including A. minor Lange-Bertalot and A. densistriatus.