Note: Do not rely on this information. It is very old.
Echinanthus is the name of an important genus of Sea-urchins, and belongs to the family Clypeastridee. The best-known species is the West Indian Echinanthus rosaceus, Linn, (or, more strictly, Echinanthus reticulatus, Linn.). The members of this genus differ from Echinanthus in the fact that the margins are swollen and the base rounded, instead of sharp and flat respectively. The name has often been applied to a genus of fossil forms belonging to a different group.