ae 
NORMA LATERALIS OF THE SKULL. 149 
mastoidea), much simpler and less serrated than the two previously 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 
19 20 21 22 23 
Fic. 115.—NormMa LATERALIS. 
1. Mental foramen. 12. Lambdoid suture. 22. Stephanion. 
2. Body of lower jaw. 13. Occipital bone. 23. Frontal bone. 
3. Superior maxilla. 14, Lambda. 24, Pterion. 
4, Ramus of lower jaw. 15. Obelion placed between the two 25. Temporal fossa. 
| 5. Zygomatic arch. parietal foramina, 26. Great wing of sphenoid, 
6, Styloid process. 16. Parietal bone. 27. Malar bone. 
7. External auditory meatus. 17. Lower temporal ridge. 28. Malar canal. 
8. Mastoid process. 18. Upper temporal ridge. 29. Lachrymal bone. 
a 9:_Asterion. 19. Squamous part of temporal 30. Nasal bone. 
10. Superior curved line of occipital bone. 31. Infraorbital canal. 
bone. 20. Bregma. 32, Anterior nasal aperture, 
_ 11. External occipital protuberance. 21. Coronal suture. 
the great wing of the sphenoid; inferiorly it lies in plane with the middle of the 
_ zygomatic arch. ! 
The sutures around the summit of the great wing of the sphenoid are arranged 
_ like the letter H placed obliquely, the cross piece of the H corresponding to the 
“spheno-parietal suture. When this is short, and becomes a mere point of contact, 
the arrangement then resembles the letter X. This region is named the pterion. 
; Curving over the lateral region of the calvaria in a longitudinal direction is 
_ the temporal crest (linea temporalis). This is often double. The lower line marks 
_ the limit of the attachment of the temporal muscle, whilst the upper ridge defines 
