Spiniferites cingulatus ssp. polygonalis (Clarke and Verdier, 1967) Lentin and Williams, 1973

NOW Pterodinium cingulatum subsp. polygonale. Originally Hystrichosphaera cingulata var. polygonalis, subsequently Spiniferites cingulatus subsp. polygonalis, thirdly Spiniferites? cingulatus subsp. polygonalis, fourthly (and now) Pterodinium cingulatum subsp. polygonale.
Taxonomic senior synonyms (at specific rank): Hystrichosphaera (now Spiniferites) crassimurata, according to Clarke et al. (1968, p.181) and Cymatiosphaera (now Pterodinium?) pterota, according to Pavlishina (1990, p.95) — however, Paul et al. (1994, p.722) retained Hystrichosphaera cingulata subsp. polygonalis (as Pterodinium cingulatum subsp. polygonale).

Holotype: Clarke and Verdier, 1967, pl.8, fig.7; Jan du Chêne et al., 1986, pl.89, figs.7-9
Locus typicus: Isle of Wight, England
Stratum typicum: Cenomanian

Original diagnosis: Clarke and Verdier, 1967, p.46: Hystrichosphaera cingulata ssp. polygonalis
A variety of H. cingulata having a linear depressed area on each side of the ledges thereby separating a more elevated central plate area from the ledges. Both the plates and ledges are smooth.

Measurements: Holotype Range
Overall length 60 µm 55-65 µm
Overall breadth 50 µm 50-58 µm
Height of ledges 8 µm 8-11 µm

Affinities:
Clarke and Verdier, 1967, p.46: Hystrichosphaera cingulata var. polygonalis
H. cingulata var. polygonalis differs from H. cingulata var. cingulata in the presence of the striae around the plate margins.