Calcaxonia

Isididae is a family of octocorals belonging to the order Malacalcyonacea and formerly to the order Calcaxonia. Currently, the family only includes the genera Isis, Hicksonella and Rumphella.

Primnoidae is a family of soft corals.

Ellisellidae is a family of soft corals in order Scleralcyonacea.

Chrysogorgiidae is a family of soft corals in the suborder Scleralcyonacea. So far, the only fossil record for the family are specimens tentatively identified as Radicipes sp. from Oligocene deep-water strata in western Washington State, USA.

Ifalukellidae is a family of corals belonging to the order Scleralcyonacea.

Calcaxonia (1981 - 1999 known only under the informal name restricted Holaxonia) was, in some systems, an Octocorallian suborder of the order Gorgonacea, or alternatively of the broadly conceived order Alcyonacea. Before its formal erection in 1999, it was usually included inside the suborder Holaxonia.

Mopsea is a genus of coral belonging to the Mopseidae family. It comprises two species, Mopsea encrinula and Mopsea triaknema, found around the coasts of Australia at depths ranging from . Colonies are orange-brown and grow up to around in size. They comprise multiple branches from which grow feather-shaped structures. Polyps are covered in sclerites and span across the entire colony. The two species can be distinguished by the shape of their sclerites.

Scleralcyonacea is an order of the class Octocorallia.