32 



BONES OF THE HEAD. 



the condyles or articulating processes by which the head is supported 

 on the first vertebra, are the condijJar portions. 



Fig. 27. — Occipital Bone 



FKOM BELOW AND BEHIND, 

 SHOWING THE EXTEUNAL 



Surface. (A. T.) | 



1, basilar process ; 2, cou- 

 clyloid portion, the probe 

 marks the anterior condylar 

 foramen ; 3, jugular or trans- 

 verse i)rocess ; 4, external or 

 lateral angle ; 5, suvierior 

 angle ; 6, superior curved line ; 

 7, external or posterior occi- 

 pital protuberance ; 7, 8, ex- 

 ternal occipital crest ; 9, in- 

 ferior curved line ; 10, groove 

 and ridge connected with the 

 attachment of the superior 

 oblique muscle ; 11, fora- 

 men magnum ; 12, articular 

 condyle ; immediately above 

 it the posterior condylar fora- 

 men. 



The two superior bor- 

 ders are deeply serrated, 

 and are articulated with 

 the parietal bones in the lamodoidal suture. By its two inferior 



Fig. 28. — Occipital Bone 



FROM BEFORE, SHOWING THE 



Internal Surface. (A.T.) h 



1, basilar process sawn 

 through at the jilace of union 

 with the sphenoid bone ; 2, 

 condylar portion ; 3, jugular 

 or transverse process ; x , be- 

 tween 2 & 3, the sigmoid 

 groove of the lateral sinus and 

 the jugular notch ; 4, external 

 or lateral angle ; 5, superior 

 angle ; 1 to 3, the edge of 

 articulation with the petrous 

 bone ; 3 to 4, with the mas- 

 toid bone ; 4 to 5 with the 

 parietal bone ; 11, foramen 

 magnum ; 13, intei'nal occipi- 

 tal protuberance and groove of 

 the torcular Heroi^hili ; 14, in- 

 ferior spine ; 15, groove of the 

 lateral sinus ; from 5 to 13, 

 groove of the superior longi- 

 tudinal sinus ; 16, cerebral 

 fossa ; 17, cerebellar fossa. 



■^ borders, which are un- 



even but not deeply ser- 

 rated, it articulates with the mastoid and petrous portions of the 



