A Redescription of the Dinoflagellate Gymnodinium Simplex with the Aid of Electron Microscopy

Abstract

In 1908 Lohmann described a small dinoflagellate which appeared to lack a sulcus and was therefore placed in a new genus – Protodinium. The type species, P. simplex (Text-fig, IA) was broadly ellipsoidal with broad rounded apices, circular in cross-section and about 1–5 times as long as broad. The girdle was poorly defined, but was more or less median in position. The nucleus was relatively large and centrally located and yellow leaf-life chloroplasts, four to many in number, were arranged in the periphery of the cell.