THE SKULL THE CEANIUM 



185 



On the outer surface (Fig. 122) are two temporal ridges (the 

 upper one often only faintly marked), and the parietal foramen near 

 the posterior end of the superior border is larger and more constantly 

 present, 



FIG. 122. 



FIG. 123. 



LEFT PARIETAL BONE. OUTER VIEW. 



1, superior border; 2, bevelled inferior border, 

 which articulates with the squama of the tem- 

 poral bone; 3, anterior border, joining the frontal 

 bone ; 4, posterior or occipital border; 5, temporal 

 ridge ; 6, venous foramen ; 7, prolonged anterior- 

 inferior angle joining the summit of the great 

 wing of the sphenoid bone; 8, posterior-inferior 

 angle articulating with the mastoid portion of the 

 temporal bone. 



LEFT PARIETAL BONE. INNER VIEW. 



1-4, borders .corresponding with same numbers 

 in former figure ; 5, groove for the longitudinal 

 sinus, and, communicating with it, a venous fora- 

 men, 6; 7, anterior-inferior angle; 8, posterior- 

 inferior angle with the groove for the lateral 

 sinus. The arborescent lines on the inner con- 

 cave surface of the bone indicate grooves for the 

 great meningeal vessels. 



On the inner surface (Fig. 123) along the superior border is a dis- 

 tinct groove for the longitudinal sinus, and at the posterior-inferior 

 angle is a part of the groove for the lateral sinus. The inner surface, 

 although deeply concave, is not so deeply marked by the cerebral 

 convolutions ; it usually exhibits, however, near the superior border, 

 irregular impressions made by the granular nodules of the dura called 

 Pacchionian l bodies. The arborescent channels for the meningeal 

 vessels are derived from two principal branches, one from the anterior- 

 inferior angle and one from the middle of the inferior border. 



All the borders are more strongly dentate than the borders on 

 the parietal of the cat ; the anterior, moreover, is straighter, lacks the 

 upwardly directed projection, and is bevelled in its upper part at the 

 expense of the outer surface. 



THE TEMPORAL BONES. 



General Description. The Temporals are paired bones situated 

 on the sides of the skull just behind the orbits (Fig. 124). They 



1 Pacchioni (A.D. 1665-1726). 



