This Hexagonariais from the Silurian.
http://fossilsaustralia.com/hexagonaria-compound-rugose-coral/
Fossils of Australia
This Hexagonariais from the Silurian.
http://fossilsaustralia.com/hexagonaria-compound-rugose-coral/
Hexagonaria has tabulate colonies with large numbers of small but massive corallites. The numerous thickened septa do not extend into the centre and are joined together by a wide dissepimentarium. In the calyx, above the tabularium, there is a deep, narrow depression. This Hexagonaria is from the Silurian.