84 



ESSENTIALS OF ZOOLOGY 



opening are the exoccipital bones. Each bone has a rounded projec- 

 tion at its base, an occipital condyle, which articulates with the ver- 

 tebral column. 



"^ Pr^maxHlary 



Moxi/lflKy 

 — Nasal 

 ^ Sphcnethnoid 



— Fronbo -parietal 



^j y^ Pterygoid 

 -VI- Squamosal 



Pro otic 



'4^ - 1 - Squamosal 



\<mf—Quadratqjuqal 

 --xoccipitxil I *■ ' •""' "^ ' 



Columella 

 Fig. 24. — Dorsal view of the skull and upper jaw of the bullfrog. 



^ — Premaxil/ary 



— Palatine 



Fiff. 25. 



—fronbo-panetal 

 Pterygoid 



Parasphenoid 



|- -Squamosal 



- Quadratojugat 



Quadrate car- 

 ' $. tilaqe 



-Ventral view of the skull and upper jaw of the bullfrog. 



The visceral skeleton is that part of the axial skeleton which is 

 composed of the jaws and hyoid arch in the adult. The gill arches 

 of tadpoles are included in this portion. 



The hyoid apparatus is primarily cartilaginous and serves as a 

 support for the base of the tongue and the larynx. According to 

 some authors, the jaws and the hyoid were originally the branched 



