the morphology of "dunaliella" is very similar to that of "chlamydomonas," however it can be distinguished through its lack of cell wall and contractile vacuoles. instead of a rigid cell wall, the plasmalemma of "dunaliella" has a notable thick, mucilaginous coating. olivera et al. noticed that the cell coating was affected by proteolytic enzymes and neuraminidase and concluded that its makeup must be mostly glycoproteid with some neuraminic acid residues. instead of contractile vacuoles, marine species of "dunaliella" replace the organelle’s usual spot in most other chlorophyceae cells, with two to three dictyostomes that lie in a characteristic parabasal position with their forming faces toward the plasmalemma and er.