242 A MANUAL OF DENTAL ANATOMY. 



lizard will give an idea of a dentition common in the 

 group. The teeth are not very large nor very numerous, 

 there being about 30 in the jaw ; towards the front of the 

 mouth they are a little more pointed than at the back, but 

 the differences in this respect are not striking. 



At the inner side of the bases of the teeth are seen 



FIG. 101 



Nat Siz 



foramina which lead into the spaces in which new teeth are 

 being developed. 



Amongst the lizards considerable variety in the form of 

 the teeth themselves exists, some having thin serrated 

 edges, others being exceedingly blunt and rounded, but in 

 the general disposition of the teeth there is considerable 

 uniformity. 



The teeth of some lizards consist at their apices of ordinary 

 hard dentine, with a simple central pulp cavity, but at 

 their bases of plicidentine with numerous subdivisions of 

 the pulp cavity, as is seen in the Monitor lizards (Varanus, 

 see p. 77). One Mexican lizard (Helodermus), has the re- 

 putation of being poisonous, and has teeth which are 

 grooved both back and front ; but it is doubtful whether its 

 harmful powers have not been exaggerated. 



(*) Lower jaw of a Lizard (Varanus Gouldii). a. Foramina leading to 

 cavities of reserve. 



