144 



THE SKELETON. 



squamous and mastoid portion of the bone. Projecting from the lower part 

 of the squamous portion is a long arched outgrowth of bone, the zygomatic 

 process. This process is at first directed outwards, its two surfaces looking 

 upwards and downwards ; it then appears as if twisted upon itself, and runs 



Fig. 97. Left Temporal Bone. Outer Surface. 



forwards, its surfaces now looking inwards and outwards. The superior border 

 of the process is long, thin, and sharp, and serves for the attachment of the 

 temporal fascia. The inferior, short, thick, and arched, has attached to it some 

 fibres of the Masseter muscle. Its outer surface is convex and subcutaneous; 

 its inner is concave, and also affords attachment to the Masseter. The ex- 

 tremity, broad and deeply serrated, articulates with the malar bone. The 

 zygomatic process is connected to the temporal bone by three divisions, called 

 its roots an anterior, middle, and posterior. The anterior, which is short, but 

 broad and strong, runs transversely inwards into a rounded eminence, the 

 eminentia articularis. This eminence forms the front boundary of the glenoicl 

 fossa, and in the recent state is covered with cartilage. The middle root forms 

 the outer margin of the glenoid cavity ; running obliquely inwards, it termi- 

 nates at the commencement of a well-marked fissure, the Glaserian fissure ; 

 whilst the posterior root, which is strongly marked, runs from the upper border 

 of the zygoma, in an arched direction, upwards and backwards, forming the 

 posterior part of the temporal ridge. At the junction of the anterior root with 

 the zygoma is a projection, called the tubercle, for the attachment of the exter- 

 nal lateral ligament of the lower jaw ; and between the anterior and middle 

 roots is an oval depression, forming part of the glenoid fossa (VH^, a socket) t 

 for the reception of the condyle of the lower jaw. This fossa is bounded, in 

 front, by the eminentia articularis; behind, by the vaginal process; and, ex- 

 ternally, by the auditory process and middle root of the zygoma ; and is di- 

 vided into two parts by a narrow slit, the Glaserian fissure. The anterior 

 part, formed by the squamous portion of the bone, is smooth, covered in the 



