Nitzschioid
Cylindrotheca
- Frustules narrow and elongate, with drawn-out ends
- Frustules twisted
- Frustules lightly silicified
Cylindrotheca cells are solitary and are characteristically needle-like, thin and elongated in shape. The ends of the cell tend to be protracted, meaning "drawn out". The frustules are lightly silicified. The valves, including the keel and raphe canal, are twisted. As a result of the strong twist of the raphe system, the cells rotate as...