Structure of Sand Dollar (Echinarachinus): With Diagram | Zoology

In this article we will discuss about the structure of Sand Dollar (Echinarachinus) with the help of a diagram. 1. It is commonly known as "sand dollar" and is a marine echinoderm found buried in sand at the bottom of sea. 2. Body flattened and somewhat round but without any central disc or arms. 3. Whole body surface is covered [...]