• Peridinium divergens var. conica: Gran (1900)
• Peridinium conicum: (Gran) Ostenfeld e Schmidt

The cell is thecate,  solitary cell of medium dimensions pentagonal or rhombic in shape. The cell surface is reticulate. The apical pore is surrounded by a circular structure and the apical collar is made up of 6 parts.The  apical plate 1’ has the "ORTHO" shape, while the 2^nd apical intercalary plate is "quadra" or "hexa". The almost circular, descendent cingulum divides the cell into two parts: the triangular epitheca, which has straight or slightly concave sides, and the hypotheca, which also has straight sides or slightly concave sides and two short empty horns that terminate in two short spines.

Cosmopolitan.

El genero "Protoperidinium" Bergh, 1881 ("Peridinium" Ehrenberg, 1831, partim)., Revta Mus. argent. Cienc. nat. "B. Rivadavia". Hidrobiol. 3:, Balech E., 1974, 347-368.