182 



OSTEOLOGY 





is the median nuchal line ending above at the external occipital protuberance, while 

 on either side are the superior and inferior nuchal lines; these, as well as the surfaces 

 of bone between them, are rough for the attachment of the muscles which are 

 enumerated on pages 129 and 130. 



Norma Lateralis (Fig. 188). When viewed from the side the skull is seen to 

 consist of the cranium above and behind, and of the face below and in front. The 

 cranium is somewhat ovoid in shape, but its contour varies in different cases and 

 depends largely on the length and height of the skull and on the degree of promi- 

 nence of the superciliary arches and frontal eminences. Entering into its formation 

 are the frontal, the parietal, the occipital, the temporal, and the great wing of the 



FIG. 188. Side view of the skull. 



sphenoid. These bones are joined to one another and to the zygomatic by the follow- 

 ing sutures : the zygomaticotemporal between the zygomatic process of the temporal 

 and the temporal process of the zygomatic; the zygomaticofrontal uniting the zygo- 

 matic bone with the zygomatic process of the frontal ; the sutures surrounding the 

 great wing of the sphenoid, viz., the sphenozygomatic in front, the sphenofrontal 

 and sphenoparietal above, and the sphenosquamosal behind. The sphenoparietal 

 suture varies in length in different skulls, and is absent in those cases where the 

 frontal articulates with the temporal squama. The point corresponding with the 

 posterior end of the sphenoparietal suture is named the pterion; it is situated about 

 3 cm. behind, and a little above the level of the zygomatic process of the frontal 

 bone. 



