_Origin_ by the superficial aponeurosis from the ridge which runs
lengthwise of the outer surface of the malar bone, and by fleshy fibres
from the surface of the malar bone ventrad of this ridge. The fibres
pass obliquely caudad to their insertion.
_Insertion._--The caudal half of the lateral margin of the ventral
border of the mandible, by a sheet of fascia which lies on the inner
surface of the muscle. The superficial fibres curve ventrad of the
mandible and are inserted into a tendinous intersection between this
muscle and the internal pterygoid (Fig. 66, _c_).