| echinoid | <zoology> Of or pertaining to the Echinoidea. One of the Echinoidea. Origin: Echinus. Source: Websters Dictionary (01 Mar 1998) |
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| echinoidea | <zoology> The class Echinodermata which includes the sea urchins. They have a calcareous, usually more or less spheroidal or disk-shaped, composed of many united plates, and covered with movable spines. See Spatangoid, Clypeastroid. Alternative forms: Echinidea, and Echinoida. Origin: NL. See Echinus, and -oid. Source: Websters Dictionary (01 Mar 1998) |