RADULA

plural Radulae, or Radulas, horny, ribbonlike structure found in the mouths of all mollusks except the bivalves. The radula, part of the odontophore, may be protruded, and it is used in drilling or in rasping food particles from a surface. It is supported by a cartilage-like mass and is covered with rows of many small teeth (denticles). New sections are constantly produced to replace those worn away at the front.