fi4l THE SKULL AS A WHOLE. 



wn 



front is the lachrymal groove, formed by the superior maxillary and lachrymal bones, 

 and leading into the nasal duct ; farther back, between the 'ethmoid and frontal 

 bones are the anterior and posterior internal orbital canals ; on the roof, at its 

 anterior margin, is the supraorbital foramen or notch ; within the external angular 

 process is the fossa for the lachrymal gland ; and in the outer wall are the temporal 

 and malar canals of the malar bone and one or two other minute foramina. 



The lateral region of the skull presents in succession from behind forwards 

 the mastoid process, the external auditory meatus, the glenoid fossa, with the condyle 



.NASAL BONE 



Fig. 66. FORE PART OF A HORIZONTAL SECTION OF THE SKULL, PASSING THROUGH THE CENTRE OF THE 



ORBIT. (G. D. T.) 



The right half of the lower portion is represented. 



of the lower jaw, the zygomatic arch, formed by the zygomatic process of the temporal 

 bone and the posterior part of the malar, and internal to this the coronoid process of 

 the lower jaw. Above the zygomatic arch is the temporal fossa, below is the zygo- 

 matic fossa, the two beiog separated by the infratemporal crest on the great wing of 

 the sphenoid (fig. 68). 



The temporal fossa is occupied by the temporal muscle, and the squamous 

 part of the temporal, the parietal, frontal, sphenoid and malar bones take part in its 

 formation. It is bounded above by the temporal crest of the frontal bone and the 

 lower temporal line of the parietal. The latter turns down posteriorly to join the 

 supramastoid crest of the temporal bone, which in front is continued into the upper 

 edge of the zygomatic arch. Along this line of bone is attached the temporal fascia, 

 which in the complete state roofs in the temporal fossa. 



The zygomatic or infratemporal fossa (fig. 68) is an irregular hollow, in part 

 covered by the ramus of the lower jaw. Its wall is formed internally by the external 



