THE SKULL. 



55 



Caudally there appear in the ventral view the foramen 

 magnum {a), occipital condyles (/;), and jugular processes {c). 

 [n front of the jugular processes the two tympanic bullae {d) 

 form prominent features, with the mastoid process {e), the 

 stylomastoid foramen [/), and the external auditory meatus 



Fig. 41. — Skull, Ventral View. 



I, occipital bone; 2, temporal; 3, sphenoid; 4, presplienoid; 5, frontal; 6, malar; 

 7, vomer; 8, palatine; 9, maxillary; 10, preniaxillary. a, foramen magiuim; f>, 

 occipital condyles; c, jugular process; d, tympanic bulla; e, mastoid process; f, stylo- 

 mastoid foramen; g, external auditory meatus; //, jugular foramen; /, styliform proc- 

 ess; J, groove for Eustachian tube; k, foramen ovale; /, foramen rotiindum; w, 

 pterygoid pirocess of sphenoid; ;/, perpendicular plate of jialatine; o, ciioanse or pos- 

 terior nares; /, zygomatic arch; q. cranial end of posterior palatine canal; r, pala- 

 tine grooves; s, foramina incisiva or anterior palatine foramina; /, opening of ptery- 

 goid canal. 



{g) on their lateral surfaces. All these structures have been 

 described. The tympanic bulla; {d) are placed with long axes 

 directed craniomediad, so that they converge toward their 

 cranial ends. At the caudomedial angle of each bulla is the 



