01 n. pl. A large class of Echinodermata, including numerous extinct families and genera, but comparatively few living ones. Most of the fossil spec…
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A large class of Echinodermata, including numerous extinct families and genera, but comparatively few living ones. Most of the fossil species, like some that are recent, were attached by a jointed stem. See Blastoidea, Cystoidea, Comatula.(Zool.) See: Blastoidea, Cystoidea, Comatula