240 MAMMALIAN ANATOMY 



The squamous length is the basal length of the squamous from 

 the beginning of the anterior border to the posterior upper edge of 

 the stylo-inastoid foramen. 



The petro-squamous width is taken between the posterior root of 

 the zygoma, at its concave part, and the superior border of the petrous 

 just behind its most prominent middle part. 



The mastoid length is the distance from the upper posterior edge 

 of the stylo-mast oid foramen to the end of the squamo-mastoid upward 

 prolongation. 



The width of the auditory meatus is its longest oblique diameter 

 from behind and above forward and downward. 



The height of the auditory meatus is its shortest oblique diameter 



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from above downward and backward, at right angles to the preceding 

 diameter. 



The bullar length is the distance from the anterior spine of the 

 entotympanic to the posterior end where the mastoid and the par- 

 occipital process meet. 



* 



The bullar width is taken transversely to the preceding, across 

 the anterior part from the outer, upper, and widest part of the ecto- 

 tympanic to the inner edge of the entotympanic. 



The glenoid length is the distance from the inner edge of the 

 inferior border of the squamous along the anterior border of the 

 glenoid cavity to its outer prominent end. 



The glenoid width is the shortest distance between the most promi- 

 nent part of the lower edge of the postglenoid process and the sharp 

 edge of the anterior border of the glenoid cavity. 



