Has found a Lithothamnion marmoreum which is described by E. Perceval Wright in “Proceedings Dublin Microscopical Club”, nov. 1880 p. 11: E. Perceval Wright exhibited sections of a small mussel of marble from the “Calcaire carbonifire”, terrain primare of Namur in Belgium. This most ancient seaweed had been described by Munier-Chalmas in 1876 as Lithothamnion marmoreum. Comments the wonderful state of preservation of this fossil plant.