Brain-cavity <?/'Iguanodon. 589 



internal carotid entered the pituitary fossa. From the 

 relations of this groove, which is bounded anteriorly by a 

 well-defined rounded ridge, I am led to conclude that it 

 probably lodged a branch of the carotid which entered the 

 skull by the foramen at its upper end. 



^-.- ;:^ 





X 



/ 



■ oc c 



/m.oi'. 



cur ''^ ^ 



Side of cranium of Iguanodon, showang the various foramina. | nat. size. 



bs,, basisplienoid ; car., carotid foramen ; car' ., (?) channel for braucli of 

 carotid ; /cM.OD., fenestra ovalis ; ./?<//.. (?) foramen for brancli of 

 jutrular vein ; oc.c, occipital condyle ; tb.np., tuberculum 

 sphenoccipitale. The foramina for the nerves are marked : — 

 II., optic; III., oculo-motor; V., trigeminal; V'., channel for 

 the ophthalmic brancli of the trigeminal; IX., glosso-pharyngeal ; 

 X., vagus ; XII., hypoglossal. 



Returning again to tiie cast, we find some o mm. behind 

 the base of the fifth nerve a blunt prominence, which fills a 

 depression in the skull-wall below and in front of the convex 

 otic mass ; no foramen can be seen to pass out of the skull at 

 this point, and there can be no doubt that this prominence 

 marks the point of origin of the auditory nerve (VI 11.), and 

 perhaps the facial (VII.) may arise with it. The next root lies 

 15 mm. behind the eighth and at a somewhat lower level ; 

 this seems to be the glosso-pharyngeal (IX.). Its foramen is 



