(jim-no-din-ee-um), a so-called typical dinoflagellate. Most dinoflagellates have two flagella and they lie in grooves in the cell surface. The flagella are not evident here, but the grooves are. There is an circumferential groove (the girdle or cingulum) which wraps around the cell, and a longitudinal groove which extends from the point of flagellar insertion towards the back of the cell. This is an autotrophic dinoflagellate with numerous plastids with chlorophylls a and c. Also with an eyespot. Differential interference contrast.