66 OSSA TEMPORUM. 



were exclusively an absorption and not a deposition, we should 

 scarcely find the artery occasionally surrounded perfectly by 

 bone.] 



Fig. 13.* On the inside of the up- 



per edge of the ossa parie- 

 talia there is a large sinuos- 

 ity, frequently larger in the 

 bone of one side than of the 

 other, where the upper part 

 of the falx is fastened, and the 

 superior longitudinal sinus 

 is lodged. Part of the late- 

 ral sinuses generally makes 

 a depression near the angle 

 formed by the lower and 

 posterior edges of these bones ; and the pits made by the 

 convolutions of the brain are in no part of the skull more 

 frequent or more conspicuous, than in the internal surface of 

 these bones. 



The ossa parietalia are the most equal and smooth, and are 

 among the thinnest bones of the cranium ; but they enjoy the 

 general structure of two tables and diploe most perfectly. 



These bones are joined at their fore side to the os frontis, at 

 their long inferior angles, to the sphenoid bone ; at their lower 

 edge, to the ossa temporum ; behind to the os occipitis, or ossa 

 triquetra ; and above, to one another. 



Ossa Temporum.^ 

 The ossa temporum are situated at the lateral and inferior 



* The internal surface of the left parietal bone. 1. The superior, or sagittal 

 border. 2. The inferior, or squamous border. 3. The anterior, or coronal border. 

 4. The posterior, or larabdoidal border. 5. Part of the groove for the superior 

 longitudinal sinus. 6. The internal termination of the parietal foramen. 7. The 

 anterior inferior angle of the bone, on which is seen the groove for the trunk of 

 the arteria meningea media. 8. The posterior inferior angle, upon which is seen 

 a portion of the groove for the lateral sinus. 



f This bone has received the name of temporal, because at the region which 

 it covers, the hair usually commences to turn gray, and thus in some measure 

 indicates the different periods of life. p. 



