SKULL 



433 



in the teeth ; the mastoid process of the periotic is not exposed, 

 so that the exoccipital is in contact with the tympanic bulla. 

 In the rabbit's skull the pterygoid region is difficult to make out ; 

 the orbit and maxilke are incomplete (fenestrated) ; and the 

 zygomatic arch and supraoccipital have peculiar shapes (Figs. 342 



343). 



Fig. 342. — Side view of rabbit's skull. 



Pmx., Premaxilla ; Na., nasal ; Fr., frontal ; Pa., parietal ; 5^., squamosal ; 5.0. , supraoccipital, Per., 

 periotic ; T., tympanic (the reference line points to the bony external auditory meatus, beneath it 

 lies the inflated bulla) ; P.O. paroccipital process. 



Fig. 343. — Upper surface of rabbit's skull. — From Thomson. 



/v., Anterior nares ; PMX., premaxilla; NA., nasal ; FR., anterior part of frontal ; MX., posterior part 

 of maxilla; /., anterior part of jugal ; SOF., supraorbital process of frontal ; FRK., posterior part of 

 frontal ; //., posterior end of jugal protruding below zygomatic portion of squamosal (Z.SQ.) ; PA., 

 parietal ; A.M., external auditory meatus ; SO., supraoccipital ; IP., interparietal ; SQ., squamosal. 



