512 



ZOOLOGY 



only gives rise to a tube for the external auditory meatus, but also 

 forms the bulla tympani, a dilated bony process containing a cavity. 



The occipital region presents two condyles for the articulation of 

 the atlas. 



The mandible consists in the adult of one bone, the equivalent 





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of the dcntary of Sauropsida, on each side — the two rami, as they 

 are called, being in most Mammals closely united at the symphysis. 

 The mandible articulates with an articular surface formed for it by 

 the squamosal bone, below ^the posterior root of the zygomatic 

 arch. 



