50 INTESTINE AND DIET OF REPTILES. 



Through. these descriptions it is proved that the intesti- 

 nal canal of the lizards shows remarkable adaptations to the 

 diet of aniinals. The dentition is, on the eontrary, compara- 

 tively very little modilied because the teeth ehiefly serve to 

 secure the food not to mastieate it. The most conspicuous 

 feature with regard to the dentition is perhaps that found 

 in Uromastix (and Aporoscelis) which Boulenger^ describes 

 in the following way: »In Uromastix and Aporoscelis, however, 

 these enlarged (canine) teeth are absent and the anterior la- 

 teral teeth wearing ont with age, a toothless cutting-edge is 

 left between the molars and the incisors, which, in those two 

 genera, unite in the adiilt to form a large single or divided 

 cutting-tooth.» This is evidently an adaptation to the herbi- 

 vorons diet of these lizards. The continuous cntting-edge is 

 of course more suitable for securing pieces of herbs and ve- 

 getable tissne than a series of pointed teeth. Another adap- 

 tation is the one found in Aniblyrhynclms and Conoloplms in 

 which lizards (and also in Fhymaturus according to Boulen- 

 ger) the anterior teeth are deeply trilobate so that the series 

 of teeth form a kind of a saw which together with the same 

 of the other jaw may be useful for securing pieces of herbs 

 and algse and better suitable for such work than the conical 

 teeth of other Iguanids. In other lizards, not mentioned in this 

 paper, there are other adaptive specializations to be found 

 with regard to the dentition, but as this not at present be- 

 longs to our object of investigation it may be left till another 

 opportunity. 



is, however, a great physical resemblance and in both cases the fluid should 

 pass too qaickly through the intestiue if the lumen was wide and the food- 

 material could then not be utilized in a satisfactory nianner. 

 • Catal. of Lizards Brit. Mus. 



Trvckt den Ii augusti 1902. 



