Holotype population of Microcostatus meridionalis Peszek, M.Rybak & Kochman-Kędziora, sp. nov. A–O LM images of valve views P–AA SEM images P–T images of entire valve external views U–Z view on valve central area and valve apices AA internal view of valve. Scale bars: 10 µm (A–O), 5 µm (P, Q), 4 µm (R), 3 µm (S–U, Y–AA), 2 µm (V, W), 1 µm (X).