Hystrichosphaeridium tubiferum subsp. brevispinum

subsp. brevispinum (Davey and Williams, 1966b, p.58, pl.10, fig.10) Lentin and Williams, 1973, p.80.  Emendation: Marheinecke, 1992, p.61, as Hystrichosphaeridium proprium subsp. brevispinum.  Holotype: Davey and Williams, 1966b, pl.10, fig.10; Bujak et al., 1980, pl.8, figs.10-12; Fauconnier and Masure, 2004, pl.47, figs.1-4.  Originally Hystrichosphaeridium tubiferum var. brevispinum, subsequently (and now) Hystrichosphaeridium tubiferum subsp. brevispinum, thirdly Hystrichosphaeridium proprium subsp. brevispinum.  Lentin and Williams (1993, p.336) retained this taxon as a subspecies of Hystrichosphaeridium tubiferum.  Taxonomic senior synonym: Micrhystridium (as Dapsilidinium?, now Litosphaeridium) fucosum, according to Below (1982c, p.29) - however, Lentin and Williams (1985, p.190) retained Hystrichosphaeridium tubiferum subsp. brevispinum.  Age: Early Eocene.Hystrichosphaeridium tubiferum