118 



BONES OF THE SKULL. 



Fig. 81. 



Fig. 81 is the in- 

 ternal surface of the 

 same bone, shewing the 

 broad and shallow de- 

 pressions (17 and 18) 

 produced by the con- 

 volutions of the ante- 

 rior lobes of the cere- 

 brum and the internal 

 crest (1 9 and 20), which 

 gives attachment to the 

 dura mater. 



Fig. 82 represents 

 the external surface of 

 the parietals (ossa pa- 

 rietalia) . At its upper 

 (6), anterior (5), and 

 posterior borders (7), 

 are seen the serrated 

 J5 edges of the suture, and 

 at its lower border (8), 

 the bevelled edge, 

 which is overlapped by 

 the temporal bone. 



Fig. 83 is the inter- 

 nal surface of the same 

 bone, and at the lower 

 anterior angle is shewn 

 the canal (12) for lodg- 

 ing the middle artery 

 of the dura mater, 

 which is here seen to 

 groove the bone with 

 Hts numerous branches 

 (b). 



On the internal sur- 

 face of the parietal 

 bones (fig, 84) we ob- 

 serve the longitudinal 

 groove, sulcus longi- 

 (1, 1, 1), for 



the longitudinal sinus 



