cnidarian -
radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms
coelenteron the saclike body cavity of a coelenterate
polyp one of two forms that coelenterates take (e.g. a hydra or coral): usually sedentary with a hollow cylindrical body usually with a ring of tentacles around the mouth; "in some species of coelenterate, polyps are a phase in the life cycle that alternates with a medusoid phase"
medusan,
medusoid,
medusa one of two forms that coelenterates take: it is the free-swimming sexual phase in the life cycle of a coelenterate; in this phase it has a gelatinous umbrella-shaped body and tentacles
jellyfish any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans
scyphozoan any of various usually free-swimming marine coelenterates having a gelatinous medusoid stage as the dominant phase of its life cycle
hydroid,
hydrozoan colonial coelenterates having the polyp phase dominant
