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.
Webster's Revised Unabridged Dictionary, © 1996, 1998 MICRA, Inc.
Cite This Source

radially symmetrical marine invertebrates including e.g. starfish and sea urchins and sea cucumbers 
WordNet® 3.0, © 2006 by Princeton University.
Cite This Source
Copyright © 2014, LLC. All rights reserved.
  • Please Login or Sign Up to use the Recent Searches feature