Stephanoeca deminutiva (Norris, 1965) Throndsen, 1974. Cells ovoid, with collar and flagellum. Cells within loricae composed of longitudinal and transverse costae. Lorica with narrow basal part enclosing cell and broader anterior part enclosing collar. Broad part of lorica composed of 7 longitudinal costae, evenly spaced, three or four transverse costae spaced at more or less equal intervals. Base of lorica with 4-6 transverse costae, more or less evenly spaced. Longitudinal costae not observed in basal area. Loricae sessile or on stalks up to 6.5 microns long. Cell 4-5 microns long, 3-3.5 microns wide, base of lorica 3.5-6.5 microns long, 3-5 microns wide, anterior part of lorica 6.5 microns long, 5-8 microns wide, orifice 5-6.5 microns wide.
