OCCIPITAL BOXE. 



59 



tubercle for the attachment of the ligaments (check) which connect this bone with 

 the odontoid process of the axis ; whilst external to them is a rough tubercular 

 prominence, the transverse or jugular process (the representative of the trans- 

 verse process of a vertebra), channelled in front by a deep notch, which forms 

 part of the jugular foramen. The under surface of this process affords attach- 

 ment to the Kectus capitis lateralis ; its upper or cerebral surface presents a deep 

 groove, which lodges part of the lateral sinus, whilst its prominent extremity is 

 marked by a quadrilateral rough surface, covered with cartilage in the fresh state, 

 and articulating with a similar surface on the petrous portion of the temporal 

 bone. On the outer side of each condyle, near its forepart, is a foramen, the 

 anterior condyloid ; it is directed downwards, outwards, and forwards, and trans- 

 mits the hypoglossal nerve. This foramen is sometimes double. Behind each 

 condyle is a fossa, 1 perforated at the bottom by a foramen, the posterior condyloid, 

 for the transmission of a vein to the lateral sinus. In front of the foramen 

 magnum is a strong quadrilateral plate of bone, the basilar process, wider behind 

 than in front ; its under surface, which is rough, presenting in the median line a 

 tubercular ridge, the pharyngeal spine, for the attachment of the tendinous raphe 

 and Superior constrictor of the pharynx ; and on each side of it are rough depressions 

 for the attachment of the Rectus capitis anticus major, and Rectus capitis minor. 



Fig. 23. Occipital Bone : Inner Surface. 

 Su fieri or Angle 



The Internal or Cerebral Surface (fig. 23) is deeply concave. The posterior 



1 This fossa presents many variations in size. It is usually shallow, and the foramen small ; 

 occasionally wanting, on one, or both sides. Sometimes both fossa and foramen are large, but 

 confined to one side only ; more rarely, the fossa and forameu are very large on both sides. 



