The Echinus melo or watermelon sea urchin — sea urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum.
The Echinus melo or watermelon sea urchin — sea urchins are small, spiny, globular animals which, with their close kin, such as sand dollars, constitute the class Echinoidea of the echinoderm phylum.