TEMPORAL BONE. 29 



Articulations. With twelve bones ; the two parietal, the sphenoid, 

 ethmoid, two nasal, two superior maxillary, two lachrymal, and two 

 malar. 



Attachment of muscles. To two pairs ; corrugator supercilii, and 

 temporal. 



TEMPORAL BONE. The temporal bone is situated at the side and 

 base of the skull, and is divisible into a squamous, mastoid, and 

 petrous portion. 



The Squamous portion, forming the anterior part of the bone, 

 is thin, translucent, and contains no diploe. Upon its external 

 surface it is smooth, to give attachment to the fleshy fibres of the 

 temporal muscle, and has projecting from it an arched and length- 



Fig. 17* 



ened process, the zygoma. Near the commencement of the zygoma 

 upon its lower border, is a projection called the tubercle, to which 

 is attached the external lateral ligament of the lower jaw, and 



* The external surface of the temporal bone of the left side. 1. The squa- 

 mous portion. 2. The mastoid portion. 3. The extremity of the petrous por- 

 tion. 4. The zygoma. 5. Indicates the tubercle of the zygoma, and at the 

 same time its anterior root turning inwards to form the eminentia articularis. 

 6. The superior root of the zygoma, forming the posterior part of the temporal 

 ridge. 7- The middle root of the zygoma terminating abruptly at the glenoid 

 fissure. 8. The mastoid foramen. 9- The meatus auditorius externus, sur- 

 rounded by the processus auditorius. 10. The digastric fossa, situated imme- 

 diately to the inner side of (2) the mastoid process. 11. The styloid process. 

 12. The vaginal process. 13. The glenoid or Glaserian fissure; the leading 

 line from this number crosses the rough posterior portion of the glenoid fossa. 

 14. The opening and part of the groove for the Eustachian tube. 



