H and I, superior and anterior views of an aneurysm arising below the upper dural ring, within the carotid cave. This aneurysm projects upward out of the carotid cave toward the optic nerve and has the upper dural ring around its base. J and K, superior and anterior views of an ophthalmic aneurysm that arises in association with an ophthalmic artery, having its origin in the carotid cave and passing through a foramen in the optic strut to reach the optic canal. This aneurysm neck is located further laterally than the typical ophthalmic aneurysm. The aneurysm projects upward out of the cave into the subarachnoid space. L and M, superior and anterior views of an aneurysm that arises at the ophthalmic artery origin in the cavernous sinus. This ophthalmic artery passes through the superior orbital fissure to reach the orbit. This aneurysm arises below the clinoid segment and carotid cave and projects upward against the lower margin of the anterior clinoid process and does not reach the subarachnoid space. N, Superior view of superior hypophyseal aneurysm. The aneurysm arises at the distal edge of the origin of the superior hypophyseal artery and points medially under the optic chiasm. (Images courtesy of AL Rhoton, Jr.)