A sand dollar.
sand dollar definition by Webster's New World
Webster's New World College Dictionary Copyright © 2010 by Wiley Publishing, Inc., Cleveland, Ohio. Used by arrangement with John Wiley & Sons, Inc.
any of an order (Clypeasteroida) of flat, round, disklike echinoid echinoderms that live on sandy ocean beds
sand dollar definition by American Heritage Dictionary
- Any of various thin circular echinoderms of the class Echinoidea, especially Echinarachnius parma, of coastal northern Atlantic and Pacific waters, having a covering of short movable spines.
- The disklike internal skeleton of a sand dollar, having five radially symmetric oblong markings and often a pattern of slotlike holes.