The Probert Encyclopaedia of Architecture

OVOLO

In architecture an ovolo is a round, convex moulding. In Roman work it is usually a quarter circle in section; in Greek work it is flatter, and is equivalent to the echinus; that is, it has in section the elastic curve of the shell of the sea urchin. In mediaeval architecture it is not distinguishable from the multitude of convex mouldings, of all sections, which are used.
Research Ovolo