In this section
Cell wall composed of a proteinaceous pellicle (as in Euglena), but too rigid to flex. Cells generally rounded and flattened (twisted in one species), with a pointed tail at one end and a flagellum at the other, emerging from a reservoir. There is a prominent red eyespot adjacent to the reservoir, and usually a large ring of paramylon in the cell centre. The cell surface may be ridged. Chloroplasts are green and numerous.