OSTEOLOGY AND ARTHROLOGY 



119 



springs from the anterior border of the frontal — a process 

 which we have noticed in connection with this latter. 



In the pig, ox, sheep, and horse, the external surface is 

 traversed, to a greater or less extent, by a crest which is 

 situated on the prolongation of the inferior border of the 

 malar bone. This crest, which is straight in the horse, but 

 curved with its convexity upwards in the ox and the sheep, 

 is known as the maxillary spine or the malar tuberosity : it 



Fig. 62. 



18 15 



-The Skull of the Ox 



E i . c -> E \ 



Left Lateral Aspect. 



I, Occipital condyle; 2, jugular process; 3, parietal bone; 4, frontal 

 bone; 5, osseous process, which serves to support the horn (horn-core); 

 6, orbital cavity; 7, external auditory canal, in front of which is found 

 the zygomatic process ; 8, temporal fossa ; 9, superior maxillary bone ; 

 10, intermaxillary or incisor bone; 11, nasal bone; 12, anterior orifice 

 of the cavity of the nasal fossae ; 13, malar bone ; 14, lachrymal bone; 

 15, inferior maxillary bone ; 16, condyle of the inferior maxillary bone ; 

 17, incisor teeth ; 18, molar teeth. 



gives attachment to the masseter muscle, and, in the horse, 

 is distinctly visible under the skin. It does not exist in the 

 camivora. On the same surface is situated the sub-orbital 

 foramen. 



The inferior border is hollowed out into alveoli, in 

 which are implanted the superior molar and canine teeth. 

 This border is prolonged forwards from the alveolus. 



