XL] 



UNGi'LATA. 



[69 



The hyoid has a simple, elongated stylohyal without pos- 

 terior process at the upper end, but one other ossification in 

 the anterior cornu, and no glossal process to the basihyal. 



Fig. 58. — Longitudinal and vertical section of skull of a Sheeo [Ovis aries), 4. 

 PMx premaxilla; AlT maxilloturbinal ; Na nasal; itT" ethmoturbinal ; ME 

 mesethmoid ; /'"r frontal; OS orbitosphenoid ; y^^ alisphenoid ; Pa parietal; 

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

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

 sphenoid : Pt pter\goid: PI palatine; Vo vomer; Mx maxilia: cp coronoid 

 process ; cd condyle ; j sympliysis of mandible ; sh stylohyal ; eh epihyal ; ch 

 ceratohyal ; bh basihyal ; tli thyrotiyal. 



Suborder Artiodactyla. — The skull of the Sheep, as one 

 of the best known and easily procurable examples of this 

 group, may be first described, though in some respects it 

 is rather peculiarly modified- 



