Final answer:
The epicranius is composed of the frontal belly of the occipitofrontalis muscle, the occipital belly of the occipitofrontalis muscle, and the epicranial aponeurosis.
Step-by-step explanation:
The epicranius is composed of all of the above, which include the frontal belly of the occipitofrontalis muscle, the occipital belly of the occipitofrontalis muscle, and the epicranial aponeurosis.