Spiniferites ramosus var. gracilis (Davey and Williams, 1966) Corradini, 1973

Now Spiniferites ramosus ssp. gracilis. Originally Hystrichosphaera ramosa var. gracilis, subsequently Spiniferites ramosus var. gracilis, thirdly (and now) Spiniferites ramosus ssp. gracilis.
Tax. jr. synonym of Hystrichosphaeridium plicatum Maier, 1959, according to Sarjeant, 1983, who noted that Spiniferites ramosus var. gracilis must be retained, since a taxon does not have priority outside its own rank.
Harker and Sarjeant in Harker et al., 1990, retained this taxon as Spiniferites ramosus var. gracilis. Lentin and Williams, 1993, followed Lentin and Williams, 1989, and retain it as Spiniferites ramosus ssp. gracilis.

Holotype: Davey and Williams, 1966, pl.5, fig.6; Bujak et al., 1980, pl.4, figs.1-2
Age: Cenomanian-Eocene

Original diagnosis: Davey and Williams, 1966, p. 34: Hystrichosphaera ramosa ssp. gracilis
A variety of H. ramosa (Ehrenberg) with smooth, thin-walled central body bearing gonal and sutural processes. Processes solid or hollow and relatively long and slender. Crests proximal and extending along all processes often as far as the trifurcation. Gonal processes mainly trifurcate, sutural processes bifurcate, all
but smallest terminating with small trifurcation.
Dimensions: holotype: diameter of central body 35 by 43 µm, length of processes 17-23 µm. Range of London Clay specimens; diameter of central body 32-61.5 µm.
Length of processes up to 29 µm.