Diatoma sinensis sp. nov., SEM, girdle view A a complete frustule B middle detail of A, showing the valve mantle and six bands (labeled B1 to B6) of which B1 to B4 are associated with the epivalve and B5 and B6 are assigned to the hypovalve C, D two apical details of A, showing the valve mantle, six bands (labeled B1 to B6), and the closed-open-closed-open-closed-open arrangement (labeled Cl = closed and Op = open) of the apices of six bands. Scale bars: 10 μm (A); 1 μm (B–D).