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 and has a hollow cylindrical body usually with a ring of tentacles around the mouth

medusa - one of two forms that coelenterates take: is the free-swimming sexual stage in the life cycle of a coelenterate and has a gelatinous umbrella-shaped body and tentacles

class Scyphozoa, Scyphozoa - coelenterates in which the polyp stage is absent or at least inconspicuous: jellyfishes

medusan, jellyfish, medusa - 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 - no alternation of generations the medusoid phase being entirely suppressed: sea anemones; corals

phylum - (biology) the major taxonomic group of animals and plants; contains classes