Lobban (1986: 83, figs 2–10)
Cells colonial, forming monostromatic sacs with a short stalk, broadly elliptical; apical axis c. 25 µm; transapical axis c. 10 µm. Raphe straight, with apical endings bending weakly in the same direction. Striae weakly radiating throughout valve, 22–24 in 10 µm, except in central area.
Type locality, Unwin Cove, Cape Legoupil, Antarctica (c. 63.3°S 58.0°W) (Lobban, 1986).
Lobban (1986) noted that N. schefterae might be conspecific with N. cryophila and N. crucicula (W.Sm.) Donkin, and that further SEM studies are required to determine their status.