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purple sail:see jellyfishjellyfish,
common name for the free-swimming stage (see polyp and medusa), of certain invertebrate animals of the phylum Cnidaria (the coelenterates). The body of a jellyfish is shaped like a bell or umbrella, with a clear, jellylike material filling most of the space between
..... Click the link for more information. ; polyp and medusapolyp and medusa,
names for the two body forms, one nonmotile and one typically free swimming, found in the aquatic invertebrate phylum Cnidaria (the coelenterates). Some animals of this group are always polyps, some are always medusae, and some exhibit both a polyp and a medusa
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