XI.] 



ARTIODACTYLA. 



193 



sagittal suture. The frontals (Fr) are large, and usually 

 (except in some domestic races) develop from their outer 

 surface conical, curved, bony processes, cancellous within, 



Tr 



FIG. 62. Longitudinal and vertical section of skull of a Sheep (Ovis arzes), J. 

 FMx premaxilla ; MT maxillo-turbinal ; Na nasal; ET ethmoturbinal ; ME 

 mesethmoid ; Fr frontal; OS orbitosphenoid ; AS alisphenoid ; Pa parietal ; 

 SO supraoccipital ; Per periotic ; ExO exoccipital ; BO basioccipital ; pp par- 

 occipital process ; Ty styliform process of tympanic ; BS basisphenoid ; PS pre- 

 sphenoid ; Pt pterygoid ; PI palatine ; Vo vomer ; MX maxilla ; cp coronoid 

 process ; cd condyle ; .s sjinphysis of mandible ; sh stylohyal ; eh epihyal ch 

 ceratohyal ; bh basihyal; th thyrohyal. 



which are called the "horn cores," as they form the internal 

 support of the true horns. The nasals (No) are long and 

 pointed in front. The premaxillas (PMx) are slender, with 



