One of the classes under phylum Echindermata is Crinoidea. This is the class containing sea lillies and feather stars. Sea lillies are anchored to the sea floor by a stalk, but they are radially symmetric, like all echinoderms. Both sea lillies and feather stars have a water circulatory system, like other echinoderms (Invertebrates).
(a sea lily is shown directly below )
(a sea lily is shown directly below )