CHAPTER I. 



ORBITAL CAVITY, 



Orbital cavity. — According to Chauveau, this cavity- 

 is irregularly circular in outline and circumscribed by 

 the orbital process of the frontal bone, the lachrymal 



Fig. 13. 



and malar bones, and the summit of the zygomatic 

 process. At the bottom, which shows the maxillary 

 and orbital hiatus, it is confounded in the skeleton 

 with the temporal fossa.* It lodges the globe of the 



* A fibrous membrane, the ocular sheath, isolates it from the 

 temporal fossa in the majority of mammiferous animals. Only in 



19 ' 



