Plate XL IX 



Comparative Series: Under side of the skull of various Primates to show the Form and Relations of the Auditory Bulla 

 and the Position of the Internal Carotid Foramina 



All figures natural size. 



Lemur varius. Amer. Mus. No. 14024. The bristle shows the course of the internal carotid canal through the bulla. 



Notharctus osborni. Amer. Mus. No. 11466. The bulls' of both sides arc broken, showing the cochlea, the carotid canal, the Eusta- 

 chian tube of the left side. For details see Plates XLIV, XLV. 



Propithecus coqwrelU. Amer. Mus. No. 31255. The lower part of the bulla has been removed, showing the tympanic annulus and 

 part of th(> cxteriKil audit, )i-y iiiratus, the internal carotid canal and the cochlea. For details see Plates XLVI, XLVIII. 



I'cnxlirlicKs iiiiiid. .\mcr. Mus. No. 15972. The bristle indicates the foramen on the posteromedial face of the bulla, through 

 which enters a branch (art. stapcdia?) of the internal carotid artery. The prominent foramen (for. lacerum medium) in front of the bulla 

 transmits the anterior branch of the internal carotid (art. promontorii?). The left bulla is sectioned and shows the cellulae petrosae and 

 the large sinus in the mastoid. 



Necroleniur sp. Princeton Univ. Mus. On the right side, between the large bulla and the basioccipital, is a prominent foramen 

 probably for the internal carotid artery. The external auditory meatus is indicated by a bony tube lateral to the bulla. 



Alouatta sp. Amer. Mus. No. 14660. The expanded tympanic annulus forms the lateral part of the bulla, the latter being filled 

 with cellulse petrosa\ The internal carotid foramen is on the posteromedial surface of the bulla. Compare Plate XLVI. 



