"•"^l^g^^^j BARBOUR — XIPHOCERCUS 63 



no peripheral scales enlarged to form a rim. Male with a feebly developed 

 dewlap. Digits slightly dilated proximally, widely dilated at the second 

 and fchird phalanges, the distal phalanx being slender and compressed. No 

 femoral or preanal pores. Tail very strongly compressed, not prehensile. 

 Lateral teeth tricuspid, pterygoid teeth present or absent. No sternal 

 fontanelle. Abdominal ribs. 



I am unable to find pterygoid teeth in our example of heter- 

 odermus, while I find that they may or may not be present in 

 valenciennesi. They are present in one half-grown individual, 

 and absent in several adults, which I have examined. This is in 

 keeping with the findings in Dr. Boulenger's recent studies of 

 the Lacertidae (Monograph of the Lacertidae, I, 1920), where 

 he points out that these teeth are constantly either present or 

 absent in some species of Lacerta; for instance, in Lacerta vivi- 

 para {sensu lata) he speaks of their being "nearly always absent," 

 and in Lacerta laevis as being "usually present." In his Cata- 

 logue of the Lizards in the British Museum (II, 1885, p. 8), 

 Boulenger stated in his diagnosis of the genus Xiphocercus that 

 pterygoid teeth were present. Their presence or absence is 

 probably not of great significance. 



