Throndsen (1970a: 106, figs 11 (holotype), 12–20)
Manton et al. (1976a: 1940, figs 9, 10, 61–71)
Cells solitary. Lorica funnel-shaped, to 23 µm long, 16–22 µm diameter; longitudinal costae 7; transverse costae 2. Longitudinal costae comprising costal strips sometimes with slightly flattened bifurcate ends; anterior ends of longitudinal costae forming T-junctions with the anterior transverse costa; 6 of the 7 longitudinal costae merge in pairs at the level of the protoplast. Protoplast slightly obovoid, 7–8 µm long, lying close to the base of the lorica chamber, flanked by 4 costal strips. Flagellum extending beyond the anterior costa.
Inshore and oceanic areas off the Vestfold Hills, Prydz Bay, East Antarctica; Arctic waters (Throndsen, 1970); widespread throughout the Northern Hemisphere (see Leadbeater, 1973).
Cells intermediate in size between Pleurasiga reynoldsii and P. minima have also been found in Prydz Bay (see discussion under P. minima).