What is "ceriantipatharia"

Ceriantipatharia was a subclass of class Anthozoa of the phylum Cnidaria and included tube anemones and Thorny Corals. Members of Ceriantipatharia have unpaired septa. However, recent progresses in anthozoan taxonomy and phylogeny clearly showed the belonging of Thorny Corals to Hexacorallia. However, tube anemones being so different from all other Hexacorallia, their status is still unclear. They possess simple,unbranched tentacles. Messentries are unpaired. They are protected by exoskeleton, which is dark in colour.