Echinoderma

1 definition found

From The Collaborative International Dictionary of English v.0.48 [gcide]:

  Echinodermata \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}.]
     [1913 Webster]
  
     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}.
           [1913 Webster]