Section 221: Nearly the complete stapes is present: ac - anterior crus; fp - footplate; h - head; pc - posterior crus. The incudostapedial joint (arrow) between stapes head and lenticular process of the incus is visible. The chorda tympani (ct) has reached the back wall of the middle ear space at the posterior iter. Both the cochlea and vestibule (v) are still present. Only the non-sensory portion of the posterior semicircular canal (psc) remains. The endolymphatic duct (ed) can be seen within the osseous vestibular aqueduct. The inferior division (id) of the VIII nerve with branches to the cochlea and saccule is visible in the internal auditory meatus (IAM). VIIf - Mastoid segment of facial nerve.