CHAP. III. J 



SKELETON OF THE HEAD AND TIIUXK. 



SI 



Behind the post-glcnoid process, the large meatus auditorius externus 

 is to be sccu, and close behind it the stylo-mastoid foramen (12), 

 immediately internal to which is the pit for the tympano-hyal, 

 in close contiguity to which again the small mastoid process is seen 

 descending (ms). 



Looking at the side of the skull, we see above, the evenly- 

 arched outline of the cranium and face (formed by the nasals, 

 frontals, and parietals), with the straight but inclined line of the 

 occiput behind. The base of the skull is almost straight, though 



Fig 47.— Skull viewed, from behind with the Lower Jaw detached. 



a. Angle of mandible. 



b. Auditory bulla. 

 lo. Basi-oeclpital. 



c. CoroDoid process of mandible. 

 / Condyle of mandible. 



fni. Foramen magnum. 

 g. Glenoid surface. 

 (//;. Postrglenoid process. 

 ip. Inter-parietal. 

 I. Lambdoidal ridge. 

 'Ills. Mastoid proces.s. 



oc. Occipital condyle. 



1). Parietal. 



pf. Post-orbital process of frontal. 



■pj. Post-orbital process of malar. 



so. Supra-occipital. 



sq. Squamosal. 



J. Zygoma. 



14. Inferior dental foramen. 



The par-occijiital process is seen (on eaeli side) 

 between the occipital condyle (oc), and the 

 auilitor>' bulla [/;), and above the latter. 



the middle part does not descend so much as does the alveolar 

 margin in front or the auditory bulla behind. The anterior end of 

 the skull is formed by the small premaxilla (Fig. 46, pin), which 

 ascends and joins the nasal (n). Behind this the wide nasal process of 

 the maxilla {in) is interposed in front of the orbit, the anterior margin 

 of which slopes upwards and backwards. Just inside the lower part 

 of that margin is the lachrymal bone (la) with its foramen ; behind 

 which is the os planum. The frontal (,/"), palatine, pre-sphenoid, and 

 orbito-sphenoid (os), form the inner wall of the orbit. Just below 

 the front part of the inferior margin of the orbit is the infra-orbital 

 foramen (2). Behind, and on a level with this (within the orbit). 



a 



