GENERAL REMAKES ON THE SKULL. 219 



nasal spine and orbital plates of the os-frontis, with the inter- 

 nal and external angular processes, and the ethmoid bone. 



The middle division reaches from the pterygoid to the 

 styloid processes, and includes the pterygoid, azygos, and 

 spinous processes of the sphenoid bone, the glenoid cavities, 

 and petrous points of the temporal, with the cuneiform pro- 

 cess of the occipital bone. In this region are found the 

 foramina ovalia, spinalia, corotica, glenoidea, and auditoria 

 externa. The posterior division reaches from the styloid 

 processes to the external occipital protuberance, and includes 

 the styloid, vaginal processes, the two condyloid, and the 

 two mas toid processes, with their digastric fossa, ihe jugu- 

 lar ridges, the inferior and superior transverse ridges, the 

 protuberance, and the depressions of the occipital bone. 



The foramina in this division are the foramen magnum, 

 the anterior and posterior condyloid, the stylo-mastoid, the 

 posterior mastoid, the foramen lacerum posterius, and the 

 aqueductus cochlea?. 



The to? lateral regions are divided each into three por- 

 tions, an anterior or temporal, a middle or squamous, and 

 posterior or mastoid. The temporal division includes the 

 temporal fossa, and is bounded in front by the raaZar bone 

 and the external angular process of the frontal bone ; above 

 by the temporal ridge, and below by the zygomatic arch. 

 The anterior portion of the squamous bone, the greater wing 

 of the sphenoid, the malar, and a part of the frontal, form 

 this division, which is covered by the temporal muscle. 

 The temporal fossa is continuous with the zygomatic, which 

 latter is situated below the zygoma, between the tuberosity 

 of the superior maxillary, and the pterygoid process of the 

 sphenoid, and bounded externally by the zygoma and the 

 ramus of the lower jaw. The zygomatic fossa contains the 

 external pterygoid muscle, a portion of the temporal and 

 internal pterygoid, with the inferior maxillary nerve, in- 

 ternal maxillary artery and branches. 



The squamous division is formed by the squamous portion 

 of the temporal bone and is covered by the temporal muscle. 

 The mastoid division is posterior, and its most prominent 



