294 THE RABBIT 



(ii) The orbito-sphenoid, around the optic foramen, a pair of plate- 

 like bones, fused with the pre-sphenoid, forming part of the 

 wall of the cranium and of the orbits. They unite behind 

 with the frontals, squamosals, and ali-sphenoids. 

 The frontals,* forming the roof and sides of the anterior part 

 of the cranium and the upper part of the wall of the orbit ; each 

 bearing a prominent supra-orbital process, and articulating 

 with each other in the middle line. 



m 



Nasal process of 

 Premaxillfl 



Squamosal- 



Vomer- 



--Juga!-- 



Supraorbital process- 



Pterygoid- 



Basisphenoid' 



Parietal 

 """■•Tympanic bulla- 



Paroccipital process- 

 Occipital condyle-' 



ipital 



Interparietal 



Supraoccipital" ' 



Basioccipital 



"Exocc ipital 

 n Foramen magnum 



Fm. 96.^ — The Skull of the Rabbit [Lepus cnnkulus). A. Dorsal view ; B. Ventral A-iew. 



{d) The nasal region : — 



(i) The nasals,* a pair of elongate bones forming the roof of the 



nasal cavities, 

 (ii) The vomers,* a pair of slender bones fused along their ventral 



margins, forming the base of the nasal cavities, 

 (iii) The mesethmoid cartilage, which forms the vertical internasal 

 septum separating the olfactory or nasal capsules. Along its 

 lower edge are the slender vomers. It is expanded behind 

 to form the sieve-like cribriform plate, through which the 

 olfactory nerves pass to the nose, 

 (iv) The turbinals, intricate folds of very thin bone within the nasal 

 cavities. 

 The large olfactory capsules occupy a great part of the facial region of the skull. 



Note the following bones composing the sides of the skull : — 



(i) The lachrymals,* a pair of small plate-like bones forming part of the front 

 walls of the orbits and articulating with the frontals and the maxillaj. 



