The Anamones, Corals, Urchines, Stars & Jellyfishes (Cnidaria) - Phylum
The Anemones (Anthozoa) - Class
The Tube-Dwelling Anemone (Ceriantharia) - subclass

(Spirularia)
- order

(Penicillaria)
- order
(Hexacorallia) - subclass
The Tube-Dwelling Anemones
(Ceriantharia)
- order
The Sea Anemones
(Actiniaria)
- order

(Antipatharia)
- order

(Corallimorpharia)
- order
The Stony Corals
(Scleractinia)
- order
The Zoanthids
(Zoantharia)
- order
(Octocorallia) - subclass
The Soft Corals (Alcyonacea) - order

(Calcaxonia)
- suborder

(Holaxonia)
- suborder

(Alcyoniina)
- suborder

(Protoalcyonaria)
- suborder

(Scleraxona)
- suborder

(Stolonifera)
- suborder
(Helioporacea) - order

()
- order

()
- order

()
- order

()
- order
(Pennatulacea) - order

()
- order

()
- order

()
- order

()
- order
The Jellyfishes (Medusozoa) - subphylum
The Box Jellyfish, Sea Wasps (Cubozoa) - Class

(Carybdeida)
- order

(Chirodropida)
- order
The Hydroids (Hydrozoa) - Class
(Hydroidolina) - Sublass

(Anthoathecata)
- order

(Leptothecata)
- order

(Siphonophorae)
- order
(Trachylinae) - Sublass

(Actinulida)
- order

(Limnomedusae)
- order

(Narcomedusae)
- order

(Trachymedusae)
- order
The True Jellyfishes (Scyphozoa) - Class

(Coronatae)
- order

(Rhizostomae)
- order

(Semaeostomeae)
- order
The Stalked Jellyfishes (Staurozoa) - Class

(Conulatae)
- order

(Stauromedusae)
- order
The Parasites (Polypodiozoa) - Class

(Polypodiidea)
- order
The Parasites (Myxozoa) - subphylum
(Malacosporea) - Class

(Buddenbrockia)
- genera

(Tetracapsuloides)
- genera
(Myxosporea) - Class

(Bivalvulida)
- order

(Multivalvulida)
- order