Solitary thecate cell of medium dimensions, sub-ovoid in shape, posteriorly slightly broader. The cell surface is covered in areolae, each with a pore. The cingulum divides the body of the cell into two parts: the small epitheca, composed of 4 plates, and the larger hypotheca. The cingular lists are well developed and cover the epitheca The anterior crest is broader than the posterior one and forms a large bowl. The left sulcal list is long and highly developed, extending for up to 4/5 of the total length of the cell, leaving only the curved antapex free; it is supported by 3 ribs (R1, R2, R3). There is also a right dorsal list, about half as long as the left list, possibly stretching past R2). In the area of the sulcus is the flagellar opening. Inside the cell, there are chloroplasts.

Typical of marine environments.

Distribution: Europe: Great Britain (Parke & Dixon, 1976), Croatia (Vilicic et al., 2009), Romania (Caraus, 2002); Asia: Japan (Koike et al., 2006).

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

Check-list of British marine algae - third revision., Journal of the Marine Biological Association of the United Kingdom 56, Parke M., Dixon P.S., 1976, 527-594.

Mechanism of gamete fusion in Dinophysis fortii (Dinophyceae, Dinophyta): light microscopic and ultrastructural observations., Journal of Phycology 42:, Koike K., Nishiyama A., Saitoh K., Imai K., Koike K., Kobiyama A., Ogata T., 2006, 1247-1256

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