Scriniodinium playfordii Cookson and Eisenack, 1960

Taxonomic senior synonym: Gymnodinium (as and now Scriniodinium) crystallinum, according to Jan du Chêne et al. (1986a, p.316) — however, Brenner (1988, p.79) retained Scriniodinium playfordii.

Holotype: Cookson and Eisenack, 1960, pl.37, fig.6; lost according to Jan du Chêne et al.,1986
Locus typicus: Exmouth Gulf Area of Carnavron Basin, Western Australia
Stratum typicum: Oxfordian-Tithonian, Jurassic

Original descriptoin: Cookson and Eisenack, 1960, p.248
Shell flat, somewhat arched, oval in outline, divided equally by a deep circular girdle; the hypotheca is rounded; the epitheca terminates in a rather short, stout horn the apex of which is truncate and carries a small median projection. The capsule fills the cavity of the shell and projections into the base of the apical horn, its wall is thin and ornamented either entirely or at the periphery only by a small-meshed reticulum of variable width. The shell membrane is rather wide, smooth, and hyaline. A large pylome is developed.
Dimensions: holotype: 166 µm long, 147 µm broad. Range: 108-166x90-147 µm.