(G.C.Wall.) Schütt (1892: 258, fig. 64)
Coscinodiscus sol G.C.Wall. (Wallich, 1860: 38, pl. 2, fig. 1)
Ricard (1987: figs 124–128), Round et al. (1990: 134), Hasle & Syvertsen (1997: 40, pl. 2, tab. 4)
Cells solitary, discoid, with a wing of organic extrusions (stiffened mucilage?) lying around the periphery of the cell. Valves circular, 10–60 µm diameter, with a shallow mantle. Areolation radial to tangential; areolae 5–9 in 10 µm, opening internally via fine cribra and externally by larger foramina. Strutted processes in a single marginal ring; processes 4–5 in 10 µm, as well as single process near valve centre. Two labiate processes present just inside marginal ring of strutted processes. Plastids small, discoid.
Southern Ocean, south of Australia.