244 IGUANIANS. 



upper jaw and thirty on the lower jaw in full-grown individuals ; but in 

 a half-grown specimen M. Bibron found only twenty-six teeth both 

 above and below, and in a still younger individual only twenty above, 

 and eighteen below. The pterygoid teeth in this species are nine or 

 ten on each side ; small, slender, rounded, and they appear not to be 

 constant, at least in young specimens. 



The spiny- tailed Cyclurus has more numerous teeth ; from fifty 

 to fifty-six in each jaw. 



The banded Iguana, which is the type of the genus Brachylophus of 

 Cuvier, has between thirty-five and forty teeth in both the upper and 

 the lower jaw, most of which are compressed and tricuspid : there is 

 a slightly curved row of short and pointed teeth on each pterygoid 

 bone. 



The dentition of the allied genus Enyalus differs only in the larger 

 proportion of simple pointed anterior teeth. 



The Iguanoid Hyperanodon, as its name implies, has no pterygoid 



teeth. 



Most of the maxillary teeth of the Proctotreti are equal, com- 

 pressed, and trilobate, a few of the anterior ones being pointed. The 

 pterygoid teeth are still smaller and are pointed. 



The dentition of the Tropidolepes and of the toad-like Phrynoso- 

 mes difi'ers from that of the Proctotretes only in the absence of ptery- 

 goid teeth. 



In the Callisauri all the maxillary teeth are simple, nearly equal 

 and conical ; here likewise there are no pterygoid teeth. 



The insectivorous Ecphy motes have pterygoid teeth. 



In the Doryphorus the dentition begins to exhibit a little more 

 variety : the palate is edentulous ; but in the upper jaw there may be 

 distinguished eight incisives, three laminaries, and about fourteen 

 molars on each side. The laniaries are a little longer than the others, 

 rounded and slightly curved ; both these and the incisors are separated 

 by intervals : the molars have compressed, tricuspid crowns wuth the 

 middle cusp longer than the rest. 



The most strictly vegetable feeding reptiles are the true Iguance 

 and the Amhlyrhynchi ; yet the size of the teeth, their mode of implan- 

 tation and the limited motions of the jaws permit only an imperfect 



