Dinogymnium hyalinum (Vozzhennikova, 1967) Lentin and Williams, 1973

Originally Gymnodinium, subsequently Dinogymnium.
Tax. jr. synonym of Dinogymnium (originally Gymnodinium) nelsonense (Cookson, 1956) Evitt et al., 1967, according to Lentin and Vozzhennikova, 1990)
Holotype: Vozzhennikova, 1967, pl.3, fig.4; Lentin and Vozzhennikova, 1990, pl.2, fig.8, text-fig.7 (lost according to Lentin and Vozzhennikova, 1990)
Locus typicus: W Siberia (Yuzhno-Kolpachevsk area), Russia
Stratum typicum: Senonian
Translation Vozzhennikova, 1967: Lentin and Vozzhennikova, 1990

Original description: Vozzhennikova, 1967, p.45: Gymnodinium hyalinum
Theca biconical; epitheca and hypotheca almost equal in size. Transverse furrow narrow, deep, with a slightly wavy or flanged margin. Longitudinal furrow slit-like. In certain forms there are wrinkles running from the transverse furrow towards the poles. The thecal envelope is smooth and transparent.
Size: Holotype, length 67 Ám width 32 Ám; length of epicyst 27 Ám.