Bony labyrinths of three bathyergid species.

WinSurf reconstructions of the left bony labyrinths of Heterocephalus glaber, Cryptomys hottentotus and Fukomys micklemi, seen from approximately lateral (left column), posterior (middle column) and medial (right column) views. Grey shading has been added to indicate the positions of the openings into the labyrinth. The stapedes are shown in yellow. Note that Heterocephalus has fewer cochlear turns than Cryptomys and Fukomys. The lateral semicircular canal of Heterocephalus reaches the vestibule directly, whereas in Fukomys it merges with the ampulla of the posterior canal; the condition in Cryptomys is intermediate. Not to scale. APSC = ampulla for posterior semicircular canal; ASC = anterior semicircular canal; C = cochlea; DMC = dorsal mastoid cavity; ED = bony tube for endolymphatic duct; ER = epitympanic recess; FP = footplate of stapes; HM = head of malleus; LA = lenticular apophysis of incus; LPI = long process of incus; LSC = lateral semicircular canal; MI = malleoincus; MM = manubrium of malleus; OW = oval window; PC = posterior crus of stapes; PD = bony tube for perilymphatic duct (canaliculus cochleae); PMC = posteromedial mastoid cavity; PSC = posterior semicircular canal; RW = round window; SPI = short process of incus; TC = tympanic cavity; TM = tympanic membrane; TT = tensor tympani tendon; V = vestibule of inner ear; VMC = ventral mastoid cavity.