The =sterno-cephalicus= consists of two muscles. They arise from
the manubrium sterni and first rib. The superficial muscle
(Sterno-mandibularis) is inserted on the anterior border of the
masseter, the ramus of the mandible, and the buccal fascia. The
deep muscle (Sterno-mastoideus) crosses under the preceding and
ends on the mastoid process, the mandible, and, in common with the
rectus capitis anterior major, on the basilar process of the
occipital bone.
[Illustration: