Dinoflagellates - Prorocentrum
The genus Prorocentrum is widely distributed in coastal water. The cell wall consists of two halves, which are laterally compressed. A spine-like process arises at the anterior end of the cell. The cell has two large yellow or brown chloroplasts. The two flagella emerge from the apical end of the cell.
The size 36-52 my (1 my=1/1000 mm).