Fig. 2. SEM. Left valve. Anterior margin flattened and oblique. Cell center devoid of pores.
Fig. 3. SEM. Apical valve view. Periflagellar area large relative to cell size. Flagellar and auxiliary pores, and prominent angled periflagellar plate (arrowhead) adjacent to the auxiliary pore. Valves with large (arrow) and small (arrowheads) pores. A=auxiliary pore; F=flagellar pore.
Fig. 4. SEM. Intercalary band transversely striated. Small pores (arrowheads) situated in array pattern along intercalary band (plates separated during specimen preparation).