THE SKULL AND THE BONES OF THE SKULL 



69 



Ampulla of the superior semicircular canal 

 Ampulla ossea superior 



Superior semicircular canal / 



Canalis semicircularis superior 



Elliptical recess 



Recessus ellipticus 



\ 



\ 



Superior semicircular canal 

 Canalis semicircularis superior 

 (*Crus simplex 1 ) 



*Crus commune 1 -^ 



Aqueduct of the vestibule 



Aquxductus vestibuli 



External semicircular canal 



Canalis semicircularis lateralis 

 (*Crus simplex 1 ) 



Ampulla of the posterior semicircular canal 

 Ampulla ossea posterior 



Fenestra rotunda 



Fenestra cochleae 



Ampulla of the external semicircular canal 



/ Ampulla ossea lateralis 



I/ 



\ 



V, 



Petrosquamous fissure 



Fissura petrosquamosa 



Tegmen tympani 



Tegmen tympani 



Epitympanic recess, or aditus ad antruni 

 Recessus epitympanicus 



Aqueduct of Fallopius 



Canalis facialis 



- Fenestra ovalia 



Fenestra vestibuli 



' External auditory meatus 

 Meatus acusticus externus 



Tympanic sulcus 



Sulcus tympanicus 



1 Regarding the signification of the terms cms simplex and cms commune, see Appendix to Part VI., p. 95<5y, 

 note 52S . 



FIG. 141. PORTIONS OF THE OSSEOUS LABYRINTH AND THE TYMPANUM, SHOWN IN THE LEFT 

 TEMPORAL BONE BY A VERTICAL SECTION THROUGH THE PETROUS PORTION IN THE PLANE OF 

 THE SUPERIOR SEMICIRCULAR CANAL. SEEN OBLIQUELY FROM IN FRONT AND WITHIN. 



The fenestra ovalis is divided vertically. 



Posterior semicircular canal 



Canalis semicircularis posterior 



Superior semicircular canal Canalis semicircularis superior 

 Crest of the vestibule Crista vestibuli \ 



Internal auditory meatus % 



Meatus acusticus internus 



Cochlea 



Cochlea 



Carotid canal 



Canalis caroticus 



Osseous canal for the Eustachian tube 



Semicanalis tuba? auditivas 



Internal orifice of the aqueduct of the cochlea 



Apertura interna canaliculi cochlea; 



Tympanum ' 

 Cavurh tympani 



External semicircular canal 



Canalis semicircularis lateralis 



Vestibule 

 Vestibulum labyrinthi 



Pyramid, or eminentia papillaris 

 Eminentia pyramidalis 



\ External auditory meatus 

 Meatus acusticus externus 

 \Fenestra rotunda 

 Fenestra cochleae 



FIG. 142. PORTIONS OF THE OSSEOUS LABYRINTH AND THE TYMPANUM, SHOWN IN THE LEFT 

 TEMPORAL BONE BY A HORIZONTAL SECTION THROUGH THE PETROUS PORTION ALONG THE 

 INTERNAL AND THE EXTERNAL AUDITORY MEA^US. SEEN FROM ABOVE. 



Os temporale Temporal bone 



