FRONTAL BONE. 



141 



and called the supra-orbital notch or foramen. It transmits the supra-orbital 

 artery, veins, and nerve. A small aperture is seen in the upper part of the 

 notch, which transmits a vein from the diploe to join the ophthalmic vein. 

 The supra-orbital arch terminates externally in the external angular process, 



Fig. 94. Frontal .Bone. Outer Surface. 



External 

 Angular liroc. 



Kasal 



S/iin 



and internally in the internal angular process. The external angular process 

 is strong, prominent, and articulates with the malar bone: running upwards and 

 backwards from it is a sharp-curved crest, the temporal ridge, for the attach- 

 ment of the temporal fascia; and beneath it a slight concavity, that forms the 

 anterior part of the temporal fossa, and gives origin to the Temporal muscle. 

 The internal angular processes are less marked than the external, .and ar- 

 ticulate with the lachrymal bones. Between the internal angular processes is a 

 rough uneven interval, the nasal notch, which articulates in the middle line 

 with the nasal bone, and on either side with the nasal process of the superior 

 maxillary bone. The notch is continuous below with a long pointed process, 

 the nasal spine. 



Vertical Portion. Internal Surface (Fig. 95). Along the middle line is a ver- 

 tical groove, the edges of which unite below to form a ridge, the frontal crest ; 

 the groove lodges the superior longitudinal sinus, whilst its edges afford attach- 

 ment to the falx cerebri. The crest terminates below at a small opening, the 

 foramen caecum, which is generally completed behind by the ethmoid. This 

 foramen varies in size in different subjects, is usually partially or completely 

 impervious, lodges a process of the falx cerebri, and, when open, transmits a 

 vein from the lining-membrane of the nose to the superior longitudinal sinus. 

 On either side of the groove, the bone is deeply concave, presenting eminences 

 and depressions for the convolutions of the brain, and numerous small furrows 

 for lodging the ramifications of the anterior meningeal arteries. Several small, 



