REPTILES. 9 



the labial scales, and the long infra-orbital plate is a single series of rounded scales.* The scales 

 of the temples are rather large, somewhat rounded, slightly imbricated, and a few of the 

 posterior ones having the vestige of an obtuse carina. The ear is rather small, the anterior 

 margin having two slightly prominent scales towards the lower part. 



The body is depressed ; the tail moderately long, thick and slightly four-sided at the base, 

 becoming much smaller and round towards the middle. The scales of the sides of the neck 

 are small and granular ; those of the upper parts of the body small, rhomboidal, rounded 

 posteriorly, loose, much imbricated, and with an extremely low and inconspicuous carina. 

 They are arranged in about twenty-two longitudinal series. Those of the sides are larger and 

 quite smooth. The scales of the whole under part of the throat and belly are rhomboidal, 

 smooth and much imbricated ; a very few towards the sides of the abdomen are slightly notched 

 at the apex. The under surface of the anterior and the hinder surface of the posterior extre- 

 mities are covered with very fine granular scales ; those of the upper surface of the members 

 being rhomboidal, smooth, but slightly carinated and obtuse. The tail is covered with small 

 rhomboidal scales which are considerably imbricated and distinctly carinated. The scales of 

 the upper surface of the toes are smooth ; those on their sides uni-carinated, and those beneath 

 tri-carinated and broad. 



The general colour of the upper parts is a yellowish grey, with black markings, which have 

 somewhat the character, as Mons. Bibron observes, of Arabic letters. On the neck and back 

 these markings are disposed in four longitudinal series; and there are small linear markings on 

 the upper part of the shoulders and thighs. The tail is similarly marked, the under parts are 

 whitish, with brown lines and spots. 



DIMENSIONS. 



Inches. Lines. 



Length of the head 6 



of the body 1 5 



of the tail 3 



Total length .... 5 1 



Length of anterior extremity 8 



of posterior extremity 1 2 



This species is not found amongst the reptiles obtained by Mr. Darwin, but as 

 it has never been figured, it appeared very desirable that this opportunity should 

 not be lost. I am indebted to the great kindness of my friend M. Bibron for the 

 loan of the only specimen which I have seen, and from which the accompanying 

 figure is taken. It formed part of the zoological collections obtained by Mons. 

 D'Orbigny for the French Museum. 



* Mons. Bihron states that there are two series, but on examining his specimen I find a single series only. 



