• Triceratium brightwelli: West (1860)
• Ditylum trigonum: L. W. Bailey ex L. W. Bailey (1862)
• Ditylum inaequale: L. W. Bailey ex L. W. Bailey (1862)

Solitary or joined in short chains. In girdle view the frustule varies in shape from prismatic with rounded corners to almost cylindrical, usually 3-4 times longer than it is wide. In addition, the valves are barely visible in girdle view, while in valve view they are triangular to circular with a central spine. The cell wall is scarcely siliceous and is decorated with areolae, very evident in the central part and more delicate towards the outer edge. Distributed throughout the cytoplasm there are numerous small discoid chloroplasts.

Typical of marine environments.

Distribution: Europe: Croatia (Vilicic et al., 2009), Romania (Caraus, 2002); North America: Maine (Koester et al., 2007), Nova Scotia (Kim, Garbary and McLachlan, 2004).

The algae of Romania., Studii si Cercetari, Universitatea Bacau, Biologie 7, Caraus I., 2002, 1-694

Phytoplankton dynamics in Pomquet Harbour, Nova Scotia: a lagoon in the southern Gulf of St., Lawrence. Phycologia 43, Kim K.Y., Garbary D.J., McLachlan J.L., 2004, 311-328.

Sexual reproduction in the marine centric diatom Ditylum brightwellii (Bacillariophyta)., European Journal of Phycology 42(4):, Koester J.A., Brawley S.H., Karp-Boss L., Mann D.G., 2007, 351-366.

Composition and annual cycle of phytoplankton assemblages in the northeastern Adriatic Sea., Botanica Marina 52(4), Vilicic, Djakovac, Buric, Z. & Bosak, 2009, 291-305.

Synopsis des Diatomées de Belgique. Texte., Anvers: Martin Brouwers & Co., Heurck H. van, 1885, 1-235

Phytoplancton composition of the Ebro River estuary, Spain., Acta Botanica Croatica 68:, Pérez M.C., Maidana N.I., Comas A., 2009, 11-27