738 CRANIUM. 



orbitar plate on the oilier ; the junction of this ridge, and having, on each side, below that 



mass to the body of the sphenoid ; the turbi- ridge, rough depressions for the attachment 



nated process of the same bone, and, some- of the posterior recti muscles, and above that 



times, the opening into its sinus; the articular ridge, still stronger and larger marks of the 



surface for the palate bone ; and, lastly, the attachment of the complexus ; and, lastly, the 



base of the pterygoid process exhibiting the inferior aspect of the occipital protuberance, 



anterior orifice of the Vidian canal. To the extreme outside and passing from behind 



Still more outwardly is the part which forms forwards, there are the termination of the 

 the orbit, concave, and broader before than superior occipital ridge; the additamentum 

 behind. To the fore part there are, on the suturae lambdoidalis ; the posterior part of the 

 outer side, the lachrymal fossa ; on the inner mastoid portion of the temporal bone dis- 

 side the trochlear fossa, and, near to it, the playing the foramen mastoideum ; the sulcus 

 orbitar orifice of the supra-orbitary foramen, occipitalis on one hand, the mammillary pro- 

 Further back there is on the inner side a por- cess of the mastoid portion of the temporal 

 tion of the transverse suture between the hone on the other, and the sulcus digastricus 

 frontal and ethmoidal bones, containing the between the two; and, lastly, the foramen 

 two internal orbitar foramina ; and, to the stylo-mastoideum at the bottom of the sulcus 

 outer side, another portion of the same suture digastricus. Midway, and between the me- 

 between the frontal and sphenoid. A third, dian and outer portions of this region, and still 

 shorter portion connects the two preceding, passing from behind forwards, there are, the 

 and unites the frontal to the small wing of the superior occipital ridge, the inferior occipital 

 sphenoid. Behind this there are in succession ridge, and between them the marks of the 

 the foramen opticum ; the foramen lacerum attachment of the splenius capitis and trachelo- 

 orbitale superius ; the foramen rotundum ; mastoideus ; the oblique surface into which 

 and, lastly, the sulcus temporalis leading from the obliquus capitis superior is inserted ; the 

 the last foramen, and being behind the orbitar posterior condyloid fossa, containing the pos- 

 process of the sphenoid bone. terior condyloid foramen whenever it exists ; 



The middle division offers in its centre the the condyle itself; the anterior condyloid fossa 

 basilar process of the occipital bone, and the and foramen ; and, lastly, to the outside of the 

 line of its junction with the sphenoid. On it condyle, the processus lateralis. 

 are seen the indications of the attachment of The lateral region (fig. 373) is oval, and its 

 the pharyngeal and anterior recti muscles, boundaries have already been stated. Its sur- 

 Its posterior edge forms a segment of a circle face, lengthwise, is undulated, being convex 

 to assist in forming the foramen magnum, behind, where the temporal and parietal form it; 

 On either side, and from before backwards, and concave in front, where the temporal and 

 are the external and internal pterygoid pro- sphenoidal enter into its composition. Pro- 

 cesses, with the fossa navicularis, fossa ptery- ceeding from, above downwards, and com- 

 goidea, and hiatus palatinus between the two mencing with the linea temporalis, we have 

 processes ; the posterior orifice of the Vidian so much of the parietal and frontal bones as 

 canal ; the foramen lacerum anterius ; the are below that line, with the inferior extremity 

 under surface of the petrous process of the of the coronal suture between them; next, 

 temporal bone, with, on one side, the line of the sutura squamosa between the parietal and 

 its junction with the basilar process, and, on temporal bones, and part of the transverse 

 the other, the line of its junction with the suture between the frontal and sphenoid ; 

 sphenoid bone, the Eustachian sulcus occu- below this, the squamous process of the tem- 

 pying the latter ; behind the foramen lacerum poral bone, and, in front of it, the temporal 

 anterius is the rough surface for the origin of process of the sphenoid with the line of arti- 

 the levator palati and tensor tympani muscles; culation between them. These parts form the 

 the inferior orifice of the carotid canal ; the fossa temporalis, which is limited inferiorly, 

 opening of the aqueduct of the cochlea ; and, on the sphenoid by a crest which divides it 

 lastly, the foramen lacerum posterius. More from the jugal fossa belonging to the face, and 

 outwardly, and pursuing the same direction, on the temporal by a groove on the upper part 

 are the under surface of the great wing of the of the two roots of the zygomatic process, in 

 sphenoid bone; its line of union with the which play the posterior horizontal fibres of 

 temporal; the processus articularis ; the fossa the temporal muscle. Passing from behind 

 articularis ; the Glasserian fissure ; the fossa forwards, there will be observed at the lower 

 parotidea ; and, lastly, the rough inferior bor- boundary of this region, the additamentum 

 der of the foramen auditorium externum. On suturoe squamosae ; the base of the mastoid 

 the inner edge of this plane, and to the outer process ; the foramen auditorium externum ; 

 side of the sulcus Eustachianus, there are, and, lastly, the zygomatic process of the tern- 

 successively, the foramen ovale ; the foramen poral bone articulating anteriorly with the 

 spinale ; the styloid process ; the spinous pro- malar bone. 



cess, which is wedged into the Glasserian fis- The interior of the cranium presents through- 

 sure; the crest between the fossa parotidea out its entire extent more or less evidence of 

 and the foramen lacerum posterius ; the vagi- the adaptation of its surface to the convolutions 

 nal process and the styloid process. of the brain. 



The posterior division exhibits, on the me- The base is bounded, in front by the fora- 



dian line, the foramen magnum ; the longi- men ccecum ; behind, by the centre of the 



tudinal spine bisecting the inferior curved internal crucial spine; and, in its circumfe- 



