Description
Oblong-truncate cells with 2 distinctly anisokont flagel la projecting from the longitudinal axis of the cell. The flagella are held directly backwards during swimming . The cell contains a disc-shaped chloroplast with a basal pyrenoid in the region directed anteriorly during swimming. Eyespot absent. Cell covered with 2 types of small body scales in 2 layers : an inner layer of square scales and an outer layer in which each scale apparently comprises a pai r of rod -shaped scales with opposite polarity . Widespread but rarely reported marine nanoplankton organism . One species . Pseudoscourfieldia marina (Throndsen) Manton , 1975 (Fig . 20) . Cells flattened, 3.2-5 ~-tm long , 2.4-3.2 ~-tm wide , and 1.5-1 .8 ~-tm thick. Other characters above. u (OJ A B c prasinophycean flagellate . A. Whole cell. B,C. Scaly periplast in tangential (B) and transverse section (C) , showing unde rlayer of tiny square scales overlain by 'double-scales'. A=5400x . B=90 ,000x . C=75 ,000x . (After Moestrup and Throndsen, 1988) .
Type species
Figures
Raw text
Oblong-truncate cells with 2 distinctly anisokont flagel la projecting from the longitudinal axis of the cell. The flagella are held directly backwards during swimming . The cell contains a disc-shaped chloroplast with a basal pyrenoid in the region directed anteriorly during swimming. Eyespot absent. Cell covered with 2 types of small body scales in 2 layers : an inner layer of square scales and an outer layer in which each scale apparently comprises a pai r of rod -shaped scales with opposite polarity . Widespread but rarely reported marine nanoplankton organism . One species . Pseudoscourfieldia marina (Throndsen) Manton , 1975 (Fig . 20) . Cells flattened, 3.2-5 ~-tm long , 2.4-3.2 ~-tm wide , and 1.5-1 .8 ~-tm thick. Other characters above. u (OJ A B c prasinophycean flagellate . A. Whole cell. B,C. Scaly periplast in tangential (B) and transverse section (C) , showing unde rlayer of tiny square scales overlain by 'double-scales'. A=5400x . B=90 ,000x . C=75 ,000x . (After Moestrup and Throndsen, 1988) .