Differentiation from Psammothidium altaicum and P. rechtense can be difficult. The raphe valves of P. rossii have a narrow, rectangular central area, while P. rechtense has a lanceolate central area and P. altaicum has an elliptic central area. In general, rapheless valves of P. rossii have a more narrow axial area than P. altaicum, but distinguishing rapheless valves of P. rossii and P. rechtense may not be possible. Psammothidium subatomoides has a bow-tie central area, rounded apices and the frustule is not flexed. Psammothidium bioretii is larger and has a larger central area. The raphe valve of Eucocconeis lapponica has a larger, asymmetric central area.
BioData Reference
Simonsen 1987 Pl 123 Fig 1-10
BioData Reference
Krammer and Lange-Bertalot 2/4 Pl 20 Fig 24-32