Lateral View of the Medial Wall of the Right Cavernous Sinus. The anterior clinoid process has been removed. The III, IV, and V cranial nerves have been resected and the posterior and anterior bends of the cavernous carotid removed. In the specimens with a caroticoclinoid ring, the carotidoculomotor membrane continues posterior to the carotid artery below the osseous ring and continues the proximal dural ring (yellow dotted lines) up to the medial wall of the cavernous sinus. The osseous ring forms part of the roof of the cavernous sinus. The distal dural ring is represented by blue dotted lines. (Images courtesy of AL Rhoton, Jr.)