LEPUS CUNICULUS 299 



bone and the maxilla on each side. They also give oft ventrally 

 a small palatine process in the middle line which form the mesial 

 borders of the anterior palatine foramina, long oval apertuies whose 

 postero-lateral rims are completed by the maxillae, through which 

 pass the naso-palatine branches of the facial nerve. 



The malar or jugal bone is a thin flat bone attached to the body 

 of the maxilla near the zygomatic process. It runs out posteriorly, 

 intimately connected with this process and unites with a similarly 

 named projection from the squamosal bone. At its upper dorsal 

 corner it bears a slight prominence, the post-orbital process, opposite 

 to the similarly named structure on the frontal bone. These two 

 processes are but little marked in Cams, but in other mammals they 

 may be much more strongly developed and even join one another 

 so that superficially, at any rate, the orbital and temporal fossae are 

 completely separated. 



The squamosal bone is a broad scale-like bone at the lower 

 hinder end of the temporal fossa. Posteriorly it is bounded by the 

 ex-occipital and supra-occipital, above by the parietal, antero- 

 ventrally by the alisphenoid, and the hinder part of its ventral 

 border articulates with the tympanic bone. Immediately in front 

 of the bulla it sends out a stout perpendicular process, the under 

 surface of which is hollowed and smooth to form an articular surface, 

 the glenoid facet, for the lower jaw. At the hinder edge of the facet 

 is a projection running downwards, the post-glenoid process,perf orated 

 behind by the post-glenoid foramen for a branch of the lateral 

 sinus. This outgrowth, the zygomatic process, then turns forwards 

 and joins the jugal by a long oblique suture, thus completing the 

 zygoma or zygomatic arch. 



The mandible, or lower jaw, consists of two elongated somewhat 

 triangular bony plates, the rami, compressed laterally, which unite 

 in front by roughened surfaces, forming the mandibular symphysis. 

 Their union is not complete save in quite old specimens, and they 

 generally fall apart in prepared skeletons. The upper or alveolar 

 border bears the teeth. At its post ero- ventral extremity it juts 

 out to form a well-marked projection, the angular process. Just 

 above this and separated from it by a notch is a strong transverse 

 ridge, the condyle, rounded in the antero-posterior direction and 

 serving for articulation with the facet of the squamosal bone. From 

 the structure of the condyle and the facet it is clear that the jaw is 

 only capable of a simple up-and-down motion. Between the condyle 

 and the last tooth the upper edge of the ramus is thrown up into 

 a laterally compressed, backwardly curved wing, the coronoid 

 process. Below this and in front of the condyle on the outer side 

 of the jaw is a hollow space on to which the masseter muscle of 



