G6 



Mr. D. M. S. Watson 07i the 



behind this it has a long smooth articulation with the opisth- 

 otic, very well shown on both sides. Tliis suture terminates 

 behind in the foramen jngularis, the whole of whose inner 

 and lower border appears to lie in the basioecipital. 



Fig. L 



Gorgonopsid skull (B. M. Nat. Hist. 47098). Palatal aspect, x f . 



B.Oc, basioecipital; B.Sp.,basisplienoid; Ex.Oc, exoccipital ; For.Jug,^ 

 foramen jugulare ; For. Mag., foramen magnum ; Md., lower jaw; 

 Op.O., opisthotic ; Post.Tem.Foss., post-temporal fossa ; Pt., ptery- 

 goid ; Sq., squamosal. 



The exoccipital is a very small bone on the extreme back 

 of the skull. Its inner border forms a good deal of the 

 foramen magnum, but it does not meet its fellow so as to 

 exclude the supraoccipital from that opening. The bone has 

 a small notch forming the back of the foramen jugularis, 

 from which a suture runs outward separating it from the 

 opisthotic. The outer end of the bone forms part of the 

 small post-temporal fossa, and it is separated from the supra- 

 occipital by another straight suture. 



The supraoccipital is a large bone forming a great deal of 

 the occipital plate of the skull and forming the top of the 

 foramen magnum. On each side of this it has sutures with 



