12 



Bones of the Skull. 



Prominentia canalis 

 semicircularis lateralis 



Fenestra vestibuli 



Canalis facialis 

 I 



Processus cochleariformis 



Tegmen tympani 

 Antrum tympanicum 



Septum canalis musculotubarii 

 / 



/ Apertura superior canaliculi 

 / tympanici 



' / Sulcus n. petrosi superficialis 

 / / majoris 



/ / Foramen caroticum internum 



Impressio trigemini 



Foramen stylomastoideum 



I 



Eminentia pyramidalis 



Probe in 

 canaliculus 

 tympanicus 



Semicanalis m. tensoris tympani 

 Semicanalis tubae auditivae 

 Foramen caroticum externum 



Cellulae 

 mastoideae 



Feuestra cochleae 



I 



Probe in canaliculus tympanicus 

 Fossa jugularis 

 Promontorium 



11. Right temporal bone, os temporale, cut open, 



lateral view of medial half of bone. Magnification 2:1. 

 (The canalis facialis is opened in its entire length.) 



The canalis facialis (Fallopii) (0. T. Aqueduct of Faliopius) (for the a. and v stylo- 

 mastoidea , r. petrosus superficialis a. meningeae mediae ; n. facialis , n. intermedius) begins in 

 the floor of the meatus acusticus internus near the posterior surface of the pyramid, thence 

 passes lateralward, after a short course bends around at a right angle, forming the geniculum 

 canalis facialis, and from this point passes backward and lateralward and then downward. 

 In doing so it lies close to the mastoid wall of the cavity of the tympanum and there forms 

 the prominentia canalis facialis (not shown in the figure). It runs at first close beneath the 

 facies anterior pyramidis, then between the fenestra vestibuli and the prominentia canalis semi- 

 circularis lateralis, then behind the eminentia pyramidalis to terminate in the foramen stylo- 

 mastoideum. From the geniculum canalis facialis which, in the new-born (Fig. 15) lies free 

 upon the anterior surface of the pyramid, a short canal passes medianward and forward to the 

 hiatus canalis facialis (0. T. hiatus Fallopii) (for the r. petrosus superfic. a. mening. med. ; 

 n. petrosus superficialis major) ; another very delicate canal runs to the upper part of the 

 canaliculus tympanicus; behind the eminentia pyramidalis a little lateral branch is given off 

 to enter this eminence and below it arises the canaliculus chordae tympani (see Fig. 888) 

 which leads into the middle ear, and receives the canaliculus tnastoideus. 



The canalicvlus tympanicus (below for the a. tympanica inferior, above for the a. tym- 

 panica superior ; besides for the n. tympanicus and n. petrosus superficialis minor) begins with 

 the apertura inferior in the depth of the fossula petrosa, arrives in the cavum tympani on 

 its inferior wall, runs over the promontorium in the sulcus promontorii , perforates the pro- 

 cessus cochleariformis and then passes in a curved direction in the bone, forward and upward 

 to the apertura superior canaliculi tympanici on the upper surface of the pyramid ; in this 

 upper part it receives a delicate canal coming from the geniculum canalis facialis. 



