Sand Dollar, scientific name “Echinarachnius parma”, is the general name of a marine animal in the same class as starfish.
It has a hard, flattened, disc-shaped test or shell made of solidly joined plates lying just below the fine skin of the sand dollar. The small spines that densely cover the Test allow the animal to accumulate in the sand just below the surface.
Sand dollars are separated by their spines and flatter shape, which are shorter than the closely related heart urchins. More convex, short-sleeved sand dollars are also called Sea biscuits.