1 — Groove for transverse sinus; 2 — Groove for sigmoid sinus; 3 — Hypoglossal canal; 4 — Clivus; 5 — Foramen lacerum; 6 — Arterial grooves; 7 — Foramen spinosum; 8 — Foramen ovale; 9 — Anterior clinoid process; 10 — Optic canal; 11 — Cribriform plate; 12 — Frontal crest; 13 — Frontal sinus; 14 — Ethmoid; Ethmoidal bone, crista galli; 15 — Frontal bone; 16 — Sphenoid; Sphenoidal bone, lesser wing; 17 — Sphenoid; Sphenoidal bone, greater wing; 18 — Sphenoid; Sphenoidal bone, hypophysial fossa; 19 — Posterior clinoid process; 20 — Temporal bone, petrous part; 21 — Internal acoustic meatus; 22 — Jugular foramen; 23 — Foramen magnum; 24 — Cerebellar fossa; 25 — Cerebral
fossa
