THE COD. 93 



the foramen magnum above, and produced dorsally into a 

 median, laterally-compressed crest, the occipital spine. 

 The basi-, ex-, and supra-occipitals together form the 

 occipital segment of the skull. 



24. Externally to the occipital region, the brain-case is 

 produced on either side into a large out-standing mass, the 

 auditory capsule, which presents above two well-marked 

 processes an inner, the epiotic process, short and sub- 

 tetrahedral in form ; and an outer, the parotic process, 

 which is long, and projects backwards and outwards. The 

 median occipital spine and the paired epiotic and parotic 

 processes form the five projections which are so marked a 

 feature in the postero-dorsal region of the skull. 



25. The epiotic process forms nearly the whole of the 

 small epiotic bone (ep.o\ the postero-internal ossification 

 of the auditory capsule. 



26. The parotic process is constituted by two bones, 

 which are seen to meet in an irregular suture on its outer 

 surface. The uppermost of these is the pterotic (pt.o), 

 or postero-dorsal ossification of the auditory capsule, the 

 lower the opisthotic (op.o), or postero-ventral ossification : 

 the latter articulates behind with the ex-occipital, and 

 below with the basi-occipital, and is perforated near its 

 posterior border by a foramen for the exit of the glosso- 

 pharyngeal nerve. 



27. The pro otic (pr.o), a large bone, articulating behind 

 with the opisthotic and forming the antero-ventral ossifi- 

 cation of the auditory capsule : its anterior border is 

 deeply notched for the passage of the fifth and seventh 

 cerebral nerves. 



28. The sphenotic (sp.o), the antero-dorsal ossification 

 of the auditory capsule, a large, irregular bone, articulating 

 behind with the pterotic and below with the prootic. 



