The term echinus refers to a decorative element typically found in classical architecture and furniture design. It specifically refers to a convex molding or ornamentation that resembles the shape of a hollowed-out section of a sphere. The echinus is often used to decorate the top or bottom of columns, capitals, or moldings. In furniture design, echinus can be used as a decorative feature on the legs, feet, or bases of tables, chairs, and other furnishings. Greek egg-and-dart molding.