Baltisphaeridium lewisii, (Deunff, 1954), Downie and Sarjeant, 1965

Now Multiplicisphaeridium (an acritarch genus). Originally Hystrichosphaeridium, subsequently Baltisphaeridium, thirdly (and now) Multiplicisphaeridium (an acritarch genus); see also Ammonidium (an acritarch genus; combination not validly published). This combination was not validly published in Downie and Sarjeant, 1963 since these authors did not fully reference the basionym.

Holotype: Deunff, 1954, fig.3
Age: Middle Devonian