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Exochosphaeridium spinosum
From Fensome et al., 2019:
Exochosphaeridium spinosum (White, 1842, p.37, pl.4, fig.6) Davey 1969a, p.166. Holotype: White, 1842, pl.4, fig.6; lost according to Sarjeant (1966b, p.141). Originally Xanthidium (Appendix A), subsequently Hystrichosphaeridium, thirdly Baltisphaeridium (Appendix A), fourthly Cordosphaeridium (combination not validly published), fifthly Exochosphaeridium, sixthly (and now) Exochosphaeridium?. Questionable assignment: Stover and Evitt (1978, p.154). Sarjeant (1966b, p.141) speculated that this species might be the senior synonym of Hystrichodinium pulchrum. Age: Late Cretaceous.
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Original description (White, 1842):
The fifth is Xanthidium spinosum, which I so name from the singularly long tapering tentacula which characterize this species. The individuals vary in dimensions, but, upon the whole, measuring in diameter from the extremities of the tentacula, they are the largest of the species of Xanthidia, except the species tubifrum afterwards noticed. The tentacula apparent round the circumference are from fifteen to twenty-five, and they measure in diameter from the 1/500 to 1/250 of an inch.
Exochosphaeridium spinosum (White, 1842, p.37, pl.4, fig.6) Davey 1969a, p.166. Holotype: White, 1842, pl.4, fig.6; lost according to Sarjeant (1966b, p.141). Originally Xanthidium (Appendix A), subsequently Hystrichosphaeridium, thirdly Baltisphaeridium (Appendix A), fourthly Cordosphaeridium (combination not validly published), fifthly Exochosphaeridium, sixthly (and now) Exochosphaeridium?. Questionable assignment: Stover and Evitt (1978, p.154). Sarjeant (1966b, p.141) speculated that this species might be the senior synonym of Hystrichodinium pulchrum. Age: Late Cretaceous.
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Original description (White, 1842):
The fifth is Xanthidium spinosum, which I so name from the singularly long tapering tentacula which characterize this species. The individuals vary in dimensions, but, upon the whole, measuring in diameter from the extremities of the tentacula, they are the largest of the species of Xanthidia, except the species tubifrum afterwards noticed. The tentacula apparent round the circumference are from fifteen to twenty-five, and they measure in diameter from the 1/500 to 1/250 of an inch.