Fig. 2. SEM. Shape highly variable: this cell broader anteriorly than cell in Fig. 1. Apical spine missing.
Fig. 3. SEM. Periflagellar area: small shallow triangular depression on right valve. Two periflagellar pores (flagellar and auxiliary) and a small, slightly curved periflagellar plate present. Opposite is large winged apical spine.
Fig. 4. LM. Left valve. Winged apical spine visible.
Fig. 5. LM. Left valve.
Fig. 6. LM. Empty theca with visible trichocyst pores (arrows).
Fig. 7. Line drawing. Left valve. Pore arrangement.
Fig. 8. Line drawing. Right valve. Pore arrangement.