Bones of the Cranium. 



7. Frontal Bone, Os frontis, from before. 



The frontal b o 11 e is divided into : 1 frontal portion, Pars 

 frontalis, 2 orbital portions, Partes orbitalcs, and 1 nasal portion, 

 Pars nasalis. 



On the frontal portion are the two supra-orbital arches, 

 Marcjines supraorbitales, at the inner third of which is the supra-orbital 

 notch or foramen, Incisura supraorbitalis (Foramen supraorUtale) ; externally 

 the external angular or zygomatic process, Processus zygomaticus. On the 

 outer surface of the frontal portion the superciliary ridges, Arcus 

 sitperciliares ; above them the frontal eminences, Tubera frontalia, 

 between which latter is the Glabella. Running upward from the zygomatic 

 process is the temporal ridge or Linea semicircular is. At the nasal portion 

 the superior nasal spine, Spina nasalis superior, runs forward, above this 

 is the deep- dented Incisura iimnlis. 



Heitzmann, Atlas. I. 



