Diastema in some Fossil Reptiles. 



381 



mandible, described in this notice. In any case, it may be 

 interred that the crowns of the teeth, indicated by the circular 

 outlines of their roots, were slender, sharp, and conical, in 

 striking contrast with the masticating molars behind, and 

 equally in contrast with the corresponding teeth of G. kanne- 

 rneyeri. 



A more instructive dental condition is seen in the skull, 

 probably of the same species of Gomphognathus, which I found 

 at Lady Frere, indicated as R. 2578 in the British Museum. 



iC=L 



th roots. 



-i Matrix. 



First molar crown. 



Right ramus of mandible of Gomphognathus (Diastemodori) dimorphodon, 

 seen from above, showing- extent of symphysis and roots of teeth in 

 the diastema. 



In the middle of the maxillary diastema on the left side, 

 behind the canine tooth is one crown quite perfect, small, 

 strong, sharply pointed, recurved, which may be an early 

 premolar. It is the type of cutting prehensile crown which 

 may have existed in the specimen of G. polyphagus from the 

 same locality, numbered in the Brit. Mus. 2576-7, and may 

 have been present in the allied species indicated by this 

 fragment of the right mandible. The bases of these teeth are 



