Skull and Hyoid 



201 



the level of the nasal spine, where it shows the openings of the frontal sinuses on each 

 side. Between each of these and the spine is a smooth concave strip of bone that forms 

 the roof of the nasal fossa here and has the nasal nerve lying on it deep to the mucous 

 membrane. 



The deeply concave cerebral surface (Fig. 165) of the bone covers the frontal lobe 

 of the brain and is marked by its convolutions : notice how these are particularly 

 apparent on the convex surface of each orbital plate. In addition to these cerebral 



j rtr na*&f bone . 

 . coxrea 



(ju mvcovs memtrjat 

 ' of naf / note, ux'tA /viw/ netre . 



FIG. 1 66. Frontal from the side and from below. 



markings and those for meningeal vessels between it and the dura mater the cerebral 

 surface shows : 



(a) A median ridge for the attachment of the falx cerebri, passing above into 

 a groove for the superior longitudinal sinus which lies between the two layers of 

 the falx. The ridge ends below at the margin of a small pit, the foramen ccecnm, 

 just in front of the ethmoidal notch : the foramen usually transmits a minute 

 vein connecting the sinus with the veins of the frontal sinus. 



(b) Depressions near the attachment of the falx for Pacchionian bodies. 



The margins of the bone are articular. The parietal articulates along the serrated 



