Malleolus

(jnal-e'-o-lus). A part of a proce or bone having a hammer-head shape. In biology, a layer or bent-down shoot which emits roots at the notched bend. M., External, a name by which the lower extremity of the fibula is known. M., Internal, the pyramidal proce of the internal surface of the lower extremity of the tibia. Boundary, or Mallet. A small wooden hammer. M., Automatic, an instrument operated by the action of a steel spiral spring, and used for condensing gold in filling teeth. M., Electromagnetic, a dental mallet operated by electricity. M. -finger. See Finger . M., Hyde's Pneumatic, a dental mallet with an air-pump attached, which is operated by the foot, revolving a fly-wheel and a drive-wheel. M.-toe, a deformity of a toe characterized by deficient extension or undue flexion of the terminal phalanx.