THE SKULL THE CRANIUM 



177 



ridge runs parallel to the lower border, and indicates the attachment 

 of the temporal fascia. The lower part of the surface is marked by a 

 crescentic rough area for articulation with the overlapping squamous 

 plate of the temporal. 



The inferior border is short, emarginate, and irregular, often pre- 

 senting near the middle a large tooth-like process. Near its posterior 

 end it is joined obliquely by the outer border of the tentorium. 



The anterior-inferior angle is produced downward, and is more or 

 less truncated. It is overlapped by the upper part of the inner surface 



of the alisphenoid. 



FIG. 116. 



With Opposite Parietal. 



With Interparietd. 



With Frontal. 



With Alisphenoid! 



With Occipital. 



With Mastoid of Temporal. 



With the part of the 

 Tentorium formed 

 by the Alisphenoid. 



With Temporal. 

 LEFT PARIETAL, OUTER SURFACE. 



The anterior border is in the main straight and at right angles 

 to the superior and inferior borders. It is serrated, and overlaps the 

 posterior border of the frontal, in a larger degree at a point a little 

 below its middle, where a sharp process nearly reaches the base of the 

 frontal postorbital process. The suture resulting from the fronto- 

 parietal union is known as the coronal. Near the upper angle in the 

 thicker part of the border is often a foramen, the opening of a large 

 diploic canal which is continued forward into the frontal bone. 



The anterior-superior angle is well marked and is almost a right 

 angle. Its point of union with the angle of the other parietal and 

 with the contiguous angles of the frontals marks the region on the 



skull known as the bregma. 



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