LATEKAL ASPECT OF THE SKULL. 



165 



meatus the posterior border of the parietal bone turns obliquely upwards and 

 backwards, and forms with the squamous part of the occipital bone the strongly 

 denticulated sutura lambdoidea (lambdoid suture). Inferiorly this suture is con- 

 tinued obliquely downwards between the occipital bone and the posterior border of 

 the mastoid portion of the temporal, where it forms the sutura occipitomastoidea 



FIG. 169. NORMA LATERALIS OF THE SKULL. 



The occipital, sphenoid, and lacrimal bones and the'mandible are coloured blue. The parietal, zygomatic, 

 md nasal bones are coloured red. The temporal, frontal, ethmoid, and maxillary bones are left uncoloured. 



1. Mental foramen. 



2. Body of the mandible. 



3. Maxilla. 



4. Ramus of mandible. 



5. Zygomatic arch. 



6. Styloid process. 



7. External acoustic meatus. 



8. Mastoid process. 



9. Asterion. 



10. Superior nuchal line of occipital 



bone. 



11. External occipital protuberance. 



12. Lambdoid suture. 



13. Occipital bone. 



14. Lambda. 



15. Obelion placed between the two 



parietal foramina. 



16. Parietal bone. 



17. Lower temporal line. 



18. Upper temporal line. 



19. Squamous part of temporal 



bone. 



20. Bregma. 



21. Coronal suture. 



22. Stephanion. 



23. Frontal bone. 



24. Pterion. 



25. Temporal fossa. 



26. Great wing of sphenoid. 



27. Zygomatic bone. 



28. Zygomatico-facial foramen. 



29. Lacrimal bone. 



30. Nasal bone. 



31. Infra-orbital foramen. 



32. Piriform aperture and anterior 



nasal spine. 



(occipito- mastoid suture), much simpler and less serrated than the two previ- 

 ously mentioned. These three sutures just described meet in triradiate fashion 

 at a point called the asterion. 



Anteriorly the curve of the squamous suture is continued downward between 

 the anterior edge of the squamous part of the temporal and the posterior border of 

 the great wing of the sphenoid ; inferiorly it lies in plane with the middle of the 

 zygomatic arch 



