Favosites sp.

A colonial tabulate coral. The colony is built of tightly packed polygonal tubes — corallites — each of which housed one polyp, and the honeycomb pattern this produces on a broken surface gives the genus its common name.

The walls between neighbouring tubes are pierced by small openings called mural pores, which let the polyps of the colony pass nutrients between one another. Mural pores are diagnostic of the favositids and are the feature to look for under a hand lens.

Each tube is divided across by horizontal floors, the tabulae, which the polyp built beneath itself as it grew upwards. Tabulate corals are an entirely Palaeozoic group and have no living descendants.