'the cranium. 17 



temporal, superior maxillary and sphenoid bones on its inner face. Its 

 outer surface is constituted by the zygomatic process of the temporal bone, 

 by the jugal bone, and the zygomatic process of the superior maxillary. 

 The inner face is very much excavated ; its superior extending laterally 

 four inches more than its inferior edge. It measures from above downwards 

 twenty-three inches ; its width across is ten inches, and length from behind 

 forwards, thirteen. 



At the junction of the sphenoid with the upper maxillary bone is 

 seen the long spheno-maxillary fissure. At the anterior part of the 

 zygomatic fossa is the posterior oval opening of the infra-orbitar canal. 

 This, at the inlet from the fossa, is large enough to receive the hand. 

 The infra-orbitar canal is seven inches long. In front of the infra-orbitar 

 foramen is seen a small opening, which communicates with the great infra- 

 orbitar canal ; an arrangement different from that in another Mastodon 

 head of the same size, and also from that of two elephant heads. Be- 

 tween these holes and the anterior edge of the premaxillary bone we notice 

 the suture of the maxillary and intermaxillary bones, which is very distinct 

 at this part. 



The zygomatic arch, anteriorly and posteriorly, is very strong and thick. 

 Its superior edge is fissured at the junction of the temporal and jugal bones. 

 The inclination of the jugal bone is from before backwards, and from below 

 upwards, when the cranium rests on its lower surface. The union of the 

 jugal with the maxillary is close, but the suture is still persistent. The 

 temporal bone is perforated by the external auditory foramen at a short 

 distance behind the union of its zygomatic process with the jugal bone. 

 This canal measures two inches from above downwards, an inch and a 

 half across, and is in depth twelve and a half inches. 



3 



