PHYLUM:

CNIDARIA

CLASS:

ANTHOZOA

SUBCLASS: HEXACORALLIA
Mesenteries occur in pairs:
ACTINARIA Anemones

ZOANTHINIARIA

Zoanthids, e.g., Palythoa

CORALLIOMORPHARIA

Disc or coral anemones

SCLERACTINIA

Stony corals

Mesenteries occur singly:
CERIANTHARIA Tube anemones

ANTIPATHARIA

Precious black corals