136 



OSTEOLOGY 



a notch, sometimes converted into a foramen, the supraorbital notch or foramen, 

 which transmits the supraorbital vessels and nerve. A small aperture in the upper 

 part of the notch transmits a vein from the diploe to join the supraorbital vein. 

 The supraorbital margin ends laterally in the zygomatic process, which is strong 

 and prominent, and articulates with the zygomatic bone. Running upward and 

 backward from this process is a well-marked line, the temporal line, which divides 

 into the upper and lower temporal lines, continuous, in the articulated skull, with 

 the corresponding lines on the parietal bone. The area below and behind the tem- 

 poral line forms the anterior part of the temporal fossa, and gives origin to the 

 Temporalis muscle. Between the supraorbital margins the squama projects down- 

 ward to a level below that of the zygomatic processes; this portion is known as the 

 nasal part and presents a rough, uneven interval, the nasal notch, which articulates 



Zyfiomatic 

 process 



Frontal 1 spine 

 FIG. 134. Frontal bone. Outer surface. 



on either side of the middle line with the nasal bone, and laterally with the frontal 

 process of the maxilla and with the lacrimal. The term nasion is applied to the 

 middle of the frontonasal suture. From the center of the notch the nasal process 

 projects downward and forwaru beneath the nasal bones and frontal processes of 

 the maxillre, and supports the bridge of the nose. The nasal process ends below 

 in a sharp spine, and on either side of this is a small grooved surface which enters 

 into the formation of the roof of the corresponding nasal cavity. The spine forms 

 part of the septum of the nose, articulating in front with the crest of the nasal 

 bones and behind with the perpendicular plate of the ethmoid. 



The internal surface (Fig. 135) of the squama is concave and presents in the 

 upper part of the middle line a vertical groove, the sagittal sulcus, the edges of 

 which unite below to form a ridge, the frontal crest; the sulcus lodges the superior 

 sagittal sinus, while its margins and the crest afford attachment to the falx cerebri. 



