Baltisphaeridium panniforme, Gerlach, 1961

Originally Baltisphaeridium subsequently Impletosphaeridium, thirdly Cleistosphaeridium.
Tax. jr. synonym of Hystrichosphaeridium (now Systematophora) placacanthum Deflandre and Cookson, 1955, according to Sarjeant, 1984.

Holotype: Gerlach, 1961, pl.28, fig.13
Age: Middle Oligocene