A CASE OP CYCLOPIA 



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This subsequently was found to mark the point of attachment of 

 the fibrous remnants of the optic nerves. 



Middle fossa. The two carotid arteries enter the skull on 

 either side of the median ridge postero-laterally. The left carotid 

 is a mere fibrous thread, while the right carotid is somewhat larger 

 than normal. The left carotid canal is proportionately reduced. 

 These vessels approach one another, become united on the crest 

 of the median ridge and pass forward as a single vessel. At the 



Fig. 4 Diagram of floor of skull cavity, dura in situ. A.c, carotid artery A.v., 

 vertebral artery; F.M., foramen magnum; x., a slight depression in dura which 

 marks the site of attachment below of the fibrous remnant of the optic nerve. 

 The cranial nerves in their dural foramina are numbered in Roman numerals. 



Fig. 5 Diagram of floor of skull cavity, dura removed. F.M., foramen mag- 

 num; H., pit in basi-sphenoid into which were prolonged fine processes from dura; 

 M.C., median carotid artery; M.S., metopic suture; O.p.A., ophthalmic artery; 

 O.T.S., occipito-temporal suture; P.O.S., parieto-occipital suture; P.T.S., pari- 

 eto-temporal suture; R.i.c, right internal carotid artery; S., suture between 

 great wing of sphenoid and frontal element; X., marks the cut surface of bone 

 removed to expose the course of right internal carotid artery; cranial nerves in- 

 dicated in Roman numerals. The remnant of the left internal carotid artery is 

 indicated beneath the cut ends of the third and sixth nerves. 



