W.N.Ellis (1929: 77, figs 6, 7)
Leadbeater (1972e: 199, figs 7–10), Buck & Garrison (1983: 1264, figs 18, 19)
Cells solitary. Lorica 9–10 µm long, 3.8–4.6 µm diameter. Longitudinal costae 10–12; anterior longitudinal costae protruding beyond lorica, forming spines 1.5–2 µm long, slightly incurved. Transverse costae c. 16–20, spirally arranged. Intact protoplasts not seen.
Ellis Fjord, Vestfold Hills, East Antarctica (Marchant et al., 1987b); Weddell Sea (Buck & Garrison, 1983); coastal Europe (Ellis, 1929; Leadbeater, 1972e; Thomsen, 1973; Leadbeater & Morton, 1974); North Pacific (Norris, 1965).
The Antarctic specimens have the same spiral arrangement of lorica costal strips as was described in detail for coastal Denmark by Leadbeater (1972e). Smaller specimens, 6–7 µm long and with 8 longitudinal costae, were reported from the coastal North Pacific (Norris, 1965).