FOSSIL REPTILES. 309 



pediments or osseous nuts which support the teeth adhere in 

 hollows or true alveoli, formed in the thickness of the edge of 

 the jaw. 



The upper jaw of the fossil head has eleven teeth, but the 

 intermaxillary bone was wanting in the specimen ; and if, as 

 might be supposed, it had three teeth, as in the monitors, that 

 would make the number above and below equal. The river 

 monitor of Egypt has fourteen above, but only twelve below. 



In the fossil animal, all the teeth are pyramidal, and a little 

 hooked. Their external face is plane, and distinguished, by 

 two sharp crests, from their internal face, which is round, or 

 rather a demicone. 



Some of the monitors have the teeth conical, others com- 

 pressed and trenchant. The lacerta teguixin, the ameiva, the 

 iguanas, and other subgenera, have them with a denticu- 

 lated edge. There are only some fine denticulations, and 

 nearly microscopic, in the monitors with trenchant teeth. In 

 the fossil the crest is entire, and without notches. 



In all the characters now stated there is a greater approxi- 

 mation in the fossil to the monitors, than to the other saurians. 

 But in the pterygoidean bones there is a character which re- 

 moves it from them to approach it to the lizards proper, and 

 the iguanas. This is the teeth by which these bones are 

 armed. 



The crocodiles, monitors, teguixin, dracaena of M. Lacepede, 

 ameiva, dragons, stelliones, cordyles, agames, basilisks, geckos, 

 cameleons, many skinks, and the chalcides, all have the palate 

 deprived of teeth. The iguanas, the anolis, the common 

 lizards, the marbr^s {polychrus),B.h(\ a certain number of skinks, 

 alone among the saurians, partake with many serpents, batra- 

 cians, and fish, of this singular character. 



But the iguanas and other saurians have these teeth in the 

 pterygoidean bones only; the serpents in the palatine, as well as 

 pterygoidean bones. The frogs, hylcs, and salamanders have 

 them in the vomerian bones, the first on a transverse^ the 



