THE TEMPORAL BONES. 



15 



and the 2 #ondyles; its ossification being completed about the 6th year of 

 age. 



What muscles are attached to the Occipital Bone? There are 12 

 muscles attached on each side to the following portions, viz. 



Superior Curved Line 3 the occipito-frontalis, trapezius, and sterno-cleido 



mastoid. 



Space between the cttrved lines 2 the complexus and splenius. 

 Space below the inferior curved line 3 the obliquus capitis superior, rectus 



capitis posticus major and minor. 

 Basilar Process 3 the superior constrictor of the pharynx, rectus capitis 



anticus major and minor. 

 Jugular Process I the rectus capitis lateralis. 



THE TEMPORAL BONES. 



Describe their situation and divisions. They are situated at the inferior 

 lateral portions of the skull, and contain the organs of hearing. Each bone is 

 divided into 3 parts, the Squamous* (scale-like), Mastoidb (nipple-like), and 

 Petrous c (hard) ; and it is named from being the site of the first gray hairs 

 (tempus, time). 



Describe the Squamous Portion. It is a semicircular plate, smooth ex- 

 lernally, and grooved internally for the middle meningeal artery, with de- 

 pressions for the cerebral convolutions. Externally are seen the 



Zygomatic Process^ or zygoma, FIG. i. 



arising by 3 roots, and extend- 

 ing forwards to articulate with 

 the malar bone. 



Zygomatic Tubercle^ at the base 

 of the process, for the exter- 

 nal lateral ligament of the lower 

 jaw. 



Eminentia Articularis, formed by 

 the anterior root of the zygoma. 



Glenoid Fossa,g between the ante- 

 rior and middle roots of the zygo- 

 ma ; its anterior part receives the 

 condyle of the lower jaw, and is 

 covered with cartilage ; its posterior part lodges the parotid gland. 



Glasserian Fissure^ divides the glenoid fossa; it transmits the laxator 

 tympani muscle, the tympanic artery, and the processus gracilis of the 

 malleus. 



