452 



ANATOMY OF VERTEBRATES. 



304 



of which only a small portion enters into the formation of the 

 bony palate, which terminates behind opposite the interspace 

 between the penultimate and last molars. A narrow groove 

 divides the palato-pterygoid process from the socket of the last 

 molar, as in the Tapir and Rhinoceros. The pterygoid process 

 has but little antero-posterior extent: its base is perforated 



by the ectocarotid. The en- 

 topterygoids are thin plates 

 applied like splints over the in- 

 ner side of the squamous suture 

 between the pterygoid processes 

 of the palatines and alisphenoids. 

 The postglenoid process is less 

 developed than in the Tapir. 

 The Eustachian process of the 

 petro-tympanic is long and 

 styliform. There is an ante- 

 rior condyloid foramen, and a 

 wide ^ fissura lacera.' The broad 

 and convex bases of the nasals, 

 fig. 304, 8, 8, articulate with the 

 frontals, y, a little behind the 

 anterior boundary of the orbits. 

 The space between the incisors 

 and molars is of greater extent 

 than in the Tapir, fig. 301 : a 

 long diastema is not, however, 

 peculiar to the Horse, and, 

 although it allows the applica- 

 tion of the bit, that application 

 depends rather upon the general 

 nature of the Horse, and its 

 consequent susceptibility to be 

 broken in, than upon a particu- 

 lar structure which it possesses 

 in common with many other 

 The air-cells do not extend farther back than the 

 fore part of the frontals above the cranial cavity, and of the 

 basisphenoid beneath. Ossification extends into the base of the 

 tentorium and its continuation into the falx. The upper boundary 

 of the rhinencephalic fossa is much developed. 



There is a foramen, fig. 303, 9, in the premaxillary suture. 

 The zygoma, fig. 303, r, is chiefly formed by the squamosal, s. 



Skull oi iIor,-.e. 



Herbivora. 



