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Echinoidea

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noun plural Ech·i·noi·dea \ˌek-ə-ˈnȯi-dē-ə\

Medical Definition of Echinoidea

  1. :  a class of motile bottom-dwelling echinoderms comprising the sea urchins and related forms

echinoid

\ˈek-ə-ˌnȯid\play noun

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