A bony prominence; particularly, an eminence at the end of a bone bearing a rounded articular surface; -- sometimes applied also to a concave articular surface.

A heavily sclerotized projection of the mandible's dorsal surface that articulates with the cephalon in the clypeal fossa.

A rounded enlargement or process possessing an artculating surface.

One of a pair of oppositely placed protuberances on which the operculum pivots in some ascophoran cheilostomes (Hayward & Ryland, 1979). One view is that the condyles are situated beneath the operculum; whereas some similar features located above the operculum are extraopercular teeth (or lateral denticles - Tilbrook & Cook 2004). Cardellae or marginal denticles are other partial synonyms. Figures: Emballotheca, Hippoporina, Characodoma

long curved process below the beaks serving as attachment for foot muscles in pholad bivalves; also known as a myophore or aphysis.