Gymnodinium crystallinum Deflandre, 1938; Emendation: Riding and Fensome, 2003, p.12-13.

Now Scriniodinium. Originally Gymnodinium, subsequently (and now) Scriniodinium.

Holotype: Deflandre, 1938, pl.5, fig.1-2; Jan du Chêne et al., 1986, pl.104, figs.1-4
Locus typicus: Villers-sur-Mer, France
Stratum typicum: Oxfordium
Translation Deflandre, 1938: LPP

Original description: Deflandre 1938, p. 165
An empty cyst enclosed in the membrane of the cell by which it is formed, both mostly strongly flattened. Both general appearance and relative dimensions are quite variable. Cell divided into two equal parts by a fairly straight transverse furrow. Epi- and hypotheca cannot be clearly distinguished because of the absence of a longitudinal furrow. Transverse furrow seems perfectly circular. One of the poles always seems to be largely rounded, while the other is slightly projected, forming a short mamelon-like protruberance. That pole may be considered the apex. Towards the transverse furrow the epi- and hypotheca widen a little like a bell. The transverse furrow may be more or less sharply pronounced, but remains straight. The cyst (inner body) is regularly ellipsoidal or sometimes slightly acuminate towards the apex to become ovoidal. Its wall is often quite thick. Normally the cyst has a large irregular opening, situated at the side of the epitheca. This opening may be interpret- ed as the excystment-opening.
Dimension: generally: length 92(70)65 µm, breadth 85(65)58 µm.