Mallomonas cf. pseudomatvienkoae B.Y.Jo, W.Shin, H.S.Kim, Siver & R.A.Andersen

(Fig. 3C)

DISTRIBUTION. — South Korea (Jo et al. 2013); Russia (Gusev et al. 2019b); probably a widely distributed taxon but often erroneously identified as M. matvienkoae .

REMARKS

The scales of this species have base-plate pores restricted to the distal part and a thick secondary layer that covers the distal one-half to two-thirds of the scale. A single scale observed by us was entirely covered by the secondary layer of silica.