Fig. 2. SEM. Left valve. Anterior margin with flared curved apical collar. Marginal areolae observable.
Fig. 3. SEM. Lateral view. Apical area with rounded lip. Both left and right valves excavated. Wide intercalary band. Valve center concave.
Fig. 4. SEM. Apical view: periflagellar area: V-shaped depression on right valve.
Fig. 5. SEM. Areolae round to ovoid with smooth margin. Some with trichocyst pores (arrow). Ejected trichocysts (double arrows) often observed.
Fig. 6. SEM. Trichocyst pore arrangement: inside valve surface.
Fig. 7. SEM. Intercalary band smooth.
Fig. 8. SEM. Periflagellar area: auxiliary pore surrounded by curved periflagellar collar (arrowheads), adjacent to flagellar pore. Both pores equal in size. Left valve anterior margin with wide flared curved apical collar (arrow). A=auxiliary pore; F=flagellar pore.
Fig. 9. Line drawing. Areolae arrangement.
Fig. 10. Line drawing. Areolae arrangement.
Fig. 11. LM. Right valve. Intercalary band with transversely striated appearance.
Fig. 12. LM. Right valve. Intercalary with transversely striated appearance. Large posterior nucleus. N=nucleus.