AGAMOID GROUP. 125 



by the circumstance that the front teeth, instead of being small and conical, are 

 large, and in the adult united together into one or two broad cutting -teeth, 

 separated from those of the cheek-series by a gap ; while externally they are easily 

 recognised by their short tails covered with well-defined rings of spiny scales. The 

 head is remarkably short and rounded ; the body, as in most terrestrial members 



ARABIAN THORNY-TAILED LIZARD [\ nat. size). 



of the family, is much depressed ; and there is no crest along the back. There are 

 no folds or pouches on the neck, but pores are present both in front of the vent 

 and on the thighs, and the aperture of the ear is exposed. The Arabian thorny- 

 tail, or dabb, as it is termed by the Arabs ( Uromastix sjnnipes), is one of the 

 best known members of the genus, and inhabits Egypt, Crete, and Arabia. It 

 belongs to a group characterised by the rings of spiny scales on the upper surface 

 of the tail being in juxtaposition; while, in common with two other species, it 



