Solitary cells. In valve view, the cells are circular in shape, while in girdle view they appear rectangular, with the valves flat or slightly depressed in the centre, with rounded margins and the mantle high and straight. The central area of the valve surface is small and hyaline, easily distinguishable by OM. In addition, the central areolae differ in terms of shape (albeit only to a small extent) and size, increasing from the centre to about half the cell radius and then fall towards the valve margin.

Marine.

Distribution:  as Coscinodiscus argus Ehrenberg
South-east Asia: Singapore (Pham et al., 2011). Australia and New Zealand: New Zealand (Harper et al., 2012).

Phylum Ochrophyta: brown and golden-brown algae, diatoms, silicioflagellates, and kin., In: New Zealand inventory of biodiversity. Volume Three. Kingdoms Bacteria, Protozoa, Chromista, Plantae, Fungi. (Gordon, D.P. Eds), Christchurch: Canterbury University Press., Harper M.A., Cassie Cooper V., Chang F.H., Nelson W.A. e Broady P.A., 2012, 114-163

A checklist of the algae of Singapore., Singapore: Raffles Museum of Biodiversity Research, National University of Singapore., Pham M.N., Tan H.T.W., Mitrovic S.e Yeo H.H.T., 2011, 1-100.