OSTEOLOGY. 25 



along the middle line of tlie body, and its basilar process 

 forms the posterior part of the base of the cranium. It is 

 elongated from behind, where it blends with the condyles, 

 forwards, where it is roughened, coming in apposition 

 with OS sphenoides. It widens posteriorly in extending 

 upwards towards the roots of the styloid processes, exter- 

 nally to the condyles, and in these parts we see a large 

 foramen on each side, condyloid, through which the lingual 

 nerve passes. We shall simply in future note the position 

 of the foramina of the skull, as a more detailed description 

 may be found elsewhere. 



The under surface is convex, and anteriorly presents 

 roughened depressions for attachment of rectus capitis 

 anticus minor. Posteriorly it presents a small smooth 

 process, extending between the condyles, expanding poste- 

 riorly to blend with the upper surface in forming the 

 inferior part of foramen magnum. The upj^er j^ci'^t is con- 

 cave in all parts, most so posteriorly, where laterally it 

 presents the upper openings of the condyloid foramina ; 

 while anteriorly its external margins are sharpened, each 

 forming the inner boundary oi foramen lacerum basis cranii. 

 The condyles are two in number, forming the lateral 

 boundaries of foramen magnum. They are articulatory 

 prominences, convex in all parts, superiorly looking 

 upwards and slightly outwards, inferiorly downwards and 

 outwards. Their inner aspect is upwards and inwards ; 

 superiorly they join the body of the bone. From their 

 external angles run the styloid processes ; inferiorly they 

 are continued on to the basilar processes, converging, but 

 separated by a smooth concave surface. They are mainly 

 separated from the styloid processes by deep fossse, which 

 present the condyloid foramina. The styloid processes 

 are long, and extend in a downward direction, being 

 slightly curled inwards, and flattened from without in- 

 wards. They afford attachment to stylo-hyoideus, stylo- 

 maxillaris, digastricus, and obliqui capitis superior and 

 anticus, and one of the attoido-occipital ligaments. Their 

 anterior sarface at the superior part is roughened for 

 articulation with os temporale petrosum, and superiorly 

 their margin is continued upwards as the mastoid ridge to 

 the true crest of the bone. The body of the occiput is 

 continued upwards from the superior part of the condyles 

 and styloid processes laterally, centrally from the superior 



