UROMASTIX. 157 



which foreshadows the parachute of the Dragons and bears great 

 analogy to the hood of the Cobra, has led Cantor to suppose it to be 

 an arboreal form. But Mr. Theobald, who has observed it in its 

 haunts, states that it is absolutely terrestrial and a burrower, 

 like Uromastix ; that he has never seen it seek a tree, or adopt any 

 means of escape but a hasty retreat to its burrow. The use of the 

 lateral expansions to the lizard is probably to expose a greater 

 surface when sunning itself. As observed by Cantor, fear or anger 

 will cause a momentary expansion, as in the case of the Cobra. 



Genus UEOMASTIX, 

 Merrem, Tent. Syst. Amph. p. 56, 1820. 



Tympanum distinct. Incisors large, uniting in the adult into 

 one or two cutting-teeth, separated from the molars by a toothless 

 interspace. Body depressed, without crest. No gular pouch ; 

 a transverse gular fold. Tail short, depressed, covered with whorls 

 of large spinose scales. Prseanal and femoral pores present. 



Distribution. Arid tracts of North Africa and South-western 

 Asia. 7 species are known. 



These Lizards are herbi- and frugivorous, and terrestrial ; they 

 live in burrows, resembling rabbit-holes, dug by themselves. 



180. Uromastix hardwickii. 



Uromastix hardwickii, Gray, Zool. Journ. iii, 1827, p. 219 ; id. 111. 

 Ind. Zool. ii, pi. Ixxi ; Giinth. Rept. B. I. p. 155; Theob. Cat. 

 p. 119 ; Murray, Zool. Sind, p. 372 ; Bouleng. Cat. Liz. i, p. 408. 



Fig. 45. Uromastix hardwickii. 



Head small, feebly depressed, with short snout and obtuse can- 

 thus rostralis ; nostril large, directed backwards, nearer the end 

 of the snout than the eye ; tympanum large, vertically elliptical, 



