A short, thick, square muscle situated on the side of the poll. It is largely intersected by strands of tendinous tissue, and covers over the articulation between the occiput and the first cervical vertebra.

Origin. - From the anterior border and under surface of the wing of the atlas.

Insertion. - Into the mastoid crest and the styloid process of the occiput.

Action. - To incline the head to one side and to assist in extending it.