\E*chi`no*der"ma*ta\
([-e]*k[imac]`n[-o]*d[~e]r"m[.a]*t[.a]), n. pl. [NL., fr. Gr.
'echi^nos hedgehog, sea urchin + de`rma, -atos, skin.]
(Zo["o]l.)
One of the grand divisions of the animal kingdom. By many
writers it was formerly included in the Radiata. [Written
also {Echinoderma}.]



Note: The species usually have an exterior calcareous
      skeleton, or shell, made of many pieces, and often
      covered with spines, to which the name. They may be
      star-shaped, cylindrical, disk-shaped, or more or less
      spherical. The body consists of several similar parts
      (spheromeres) repeated symmetrically around a central
      axis, at one end of which the mouth is situated. They
      generally have suckers for locomotion. The group
      includes the following classes: Crinoidea, Asterioidea,
      Ophiuroidea, Echinoidea, and Holothurioidea. See these
      words in the Vocabulary, and also {Ambulacrum}.