THE TEETH OF REPTILES 101 



chians, and in this and other features they ap- 

 proach that low type. The teeth are of simple 

 conical form, of various sizes and shapes ; some- 

 times the maxillary teeth have serrated edges and 

 the beginning of tuber culated crowns. Only the 

 apices were sometimes covered by enamel. The 

 pulp-cavity sometimes has numerous divisions. 

 The succession of teeth is constant, — new teeth be- 

 ing developed by the side of the old ones and dis- 

 placing them by absorption, as is the usual form 

 of succession in ankylosed teeth. The Lacertilia 

 all possess teeth, which may be confined to the 

 maxillary, premaxillary bones and dentary pieces 

 of the mandible, or may in addition be developed 

 on the palatine and pterygoid bones. The form is 

 usually conical, but there is a suggestion of ap- 

 proach to mammalian types. Thus the Frilled 

 Lizard has canine and incisor-like teeth, and 

 other species have cuspidate crowns, or with cin- 

 gules on the sides of the crowns. The Stillio (or 

 little flying dragon) has long canine-like teeth, 

 with tricusped crowns behind. The Chameleon 

 also has cusped molars for crushing insects which 

 it catches with its long tongue. The Monitor has 

 sixteen teeth above and fourteen below, which are 

 sharp-pointed and conical. The "Horned Toad" 

 has conical teeth on the palatine and pterygoid 

 bones as well as on the maxillaries. The horned 

 Iguana has teeth in the posterior part of the jaw 



