REPTILIA 



575 



make up the skeleton of the trunk, A sacral region of two vertebrae 

 gives attachment to the pelvis. A caudal region of fourteen vertebrae 

 supports the tail. 



txterriQl narc 



Maxilla 



5upra orb'ibal 



Orbital fossa 



Parietal £ 



foramen 



Parietal 



j^^^f^ Premoxil/or 



Nasal 



Pr<Bfror>tal 



\^ Juqal 



ik___fronta/ 



iat. temporal 

 fossa 



\ Posterio- 



lateral 

 process 



Fig. 300. — Dorsal view of the skull of horned lizard. 



Vomer: 



Jugal 



iupna-_ _ 

 orbital 



BasI--- 

 occipital 



Internal nare 

 Teeth 



Palatine 



Porasphenoid 



Pbzryqoidi 



Ba 51* sphenoid 



Inferior tem- 

 poral fossa 



^Occipital condyle 



Fig. 301. — Ventral view of the skull of horned lizard. 



The pectoral girdle is composed of bone and cartilage. The two 

 anterior limbs articulate with it. The limb is a rather generalized ex- 

 ample of a typical pentadactylous vertebrate limb. The pelvic girdle 



