M/rd rttrvv. 

 Sixth nervf 



Super/or 



Sinai 



FIG. 181. Cranial surface of base of skull, with dura mater in position on the left side, the tentorium cere- 

 belli being cut away. 3 12, foramina made by the corresponding cranial nerves piercing dura mater ; 

 i. C. first cervical nerve foramen. Observe that when the dura is in position the margins of the foramen 

 magnum are not defined, owing to the continuation of the dural slope on to the odontoid, consequently 

 the foramina have the appearance of being higher than they really are in the skull. The membrane 

 covers in the pituitary fossa, forming the diaphrama sellce, attached to the inter-clinoid ligaments. 

 The structures represented on the right side are sufficiently described in the text. Compare with 

 Fig. 182 and p. 225. 



