710 B. W. KUNKEL 



situated ventral to the prominentia ampuUaris posterior and at 

 the postero-dorsal angle of the prominentia saccularis. 



On the median wall of the otic capsule are five or six foramina 

 arranged in two horizontal rows. In the ventral row are the 

 foramina acusticum anterius and posterius and the median open- 

 ing for the glossopharyngeal nerve. The foramen acusticum 

 anterius is small and is situated above and behind the foramen 

 facialis and ventral to the prominentia recessus utriculi. Close 

 behind the anterior foramen is the much larger, oval foramen 

 acusticum posterius which is situated in the antero-dorsal por- 

 tion of the prominentia saccularis. Posterior to and separated 

 by a considerable space from the last is the small foramen glosso- 

 pharyngei internum. It lies close in front of the fissura meto- 

 tica and at the upper margin of the prominentia saccularis and 

 below the prominentia ampuUaris posterior. In the upper row 

 of foramina a^e the foramen endolymphaticum, a foramen for a 

 small blood vessel and a third foramen which may or may not be 

 present and which has apparently no significance, being simply 

 an unchondrified area. The foramen endolymphaticum is situ- 

 ated postero-dorsally from the foramen acusticum posterius and 

 in front of the broad prominentia sinus superioris utriculi. The 

 small foramen for a blood vessel Ues in front of the foramen endo- 

 lymphaticum; and on the left side only in the individual modelled 

 between these two foramina is the insignificant unchondrified area 

 already mentioned. 



Viewed from the lateral side the otic capsule (fig. 28) exhibits 

 the following topography. The anterior margin of the cupula 

 anterior projects slightly laterally as a rounded ridge, the prom- 

 inentia semicircularis anterior. Below the ventral end of this, in 

 the space above the foramen facialis, is a circular convexity, 

 the prominentia recessus utriculi, which extends behind as far 

 as the fenestra vestibuli. Extending horizontally from the ven- 

 tral end of the prominentia semicircularis anterior to the ventral 

 end of the prominentia semicircularis posterior is the conspicuous 

 cylindrical ridge comprising the prominentiae ampuUaris lateralis 

 and semicircularis lateralis; ventrally this prominence merges 

 without a sharp boundary into the prominentia saccularis, 



