316 THE SKELETON OF THE RABBIT. 



long nasal process, which Jies along the 

 outer border of the nasal bone, and above 

 the maxilla and the anterior process of the 

 frontal. 



On the under surface of the skull bounded 

 laterally by the premaxillae and maxillae, 

 and behind by the hard palate, is a large 

 triangular aperture, divided longitudinally 

 into the slit-like anterior palatine foramina 

 by the palatal processes of the premaxillse, 

 a pair of thin longitudinally rolled laminae 

 attached in front to the premaxillse, and 

 enclosing the organs of unknown function 

 known as Jacobson's organs. 



v. The jugals or malars are a pair of laterally com- 

 pressed bars forming the greater part of the 

 length of the zygomatic arches, which bound 

 the orbits below. Their anterior ends are 

 fused with the zygomatic processes of the 

 maxillse, and posteriorly they articulate along 

 their dorsal edges with the squamosals. 



b. Bones in relation with the mandibular arch. 



The uppermost part of the mandibular arch 



is said to give rise to the incus and malleus, 



which have already been described in connection 



with the auditory capsule (p. 313). 



i. The squamosals are a pair of slightly curved 



bony plates, which complete the side-walls 



of the cranial cavity, lying in front of the 



periotics, and articulating with the parietals, 



frontals, orbito-sphenoids, and ali-sphenoids. 



From the hinder border of each squamosal 

 a slender post-tympanic process arches back- 

 wards over the external auditory meatus, 

 lying along the outer surface of the periotic. 



From the outer surface of the squamosal 

 arises a stout zygomatic process, which bears 



