Cnidaria

Cni`da´ri`a    (nĭ`dā´rĭ`å)

n. pl.

1.

(Zool.) A comprehensive group equivalent to the true Cœlenterata, i. e., exclusive of the sponges. They are so named from presence of stinging cells (cnidae) in the tissues. See Coelenterata.

Thesaurus

Noun

1.

Cnidaria - hydras; polyps; jellyfishes; sea anemones; corals Coelenterata, phylum Cnidaria, phylum Coelenterata Metazoa, subkingdom Metazoa - multicellular animals having cells differentiated into tissues and organs and usually a digestive cavity and nervous system cnidarian, coelenterate - radially symmetrical animals having saclike bodies with only one opening and tentacles with stinging structures; they occur in polyp and medusa forms 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 class Scyphozoa, Scyphozoa - coelenterates in which the polyp stage is absent or at least inconspicuous: jellyfishes jellyfish - any of numerous usually marine and free-swimming coelenterates that constitute the sexually reproductive forms of hydrozoans and scyphozoans class Hydrozoa, Hydrozoa - coelenterates typically having alternation of generations; hydroid phase is usually colonial giving rise to the medusoid phase by budding: hydras and jellyfishes Actinozoa, Anthozoa, class Actinozoa, class Anthozoa - a large class of sedentary marine coelenterates that includes sea anemones and corals; the medusoid phase is entirely suppressed phylum - (biology) the major taxonomic group of animals and plants; contains classes