02 THE REPTILES OF EGYPT. 
AGAMIDjE. 
AGAMA. 
Agama, part., Daud. Hist. Rept. iii. 1802, p. 333. 
Head triangular or cordate ; tympanum distinct. Body more or less depressed ; 
back sometimes feebly crested. Tail elongate, round or slightly compressed, irregularly 
or verticillately scaled. A gular pouch present or absent ; a transverse gular fold and 
a pit before the shoulder. Praeanal pores generally present in the male and occasion- 
ally in the female, but sometimes absent in both sexes. 
Before describing the first species of this genus, it is necessary to arrive at an under- 
standing of its synonymy' and of the variations to which it is subject. 
Agama mutabilis, Merrem, was founded on the lizard figured (figs. 3 & 4) on plate 5 
of the ' Description de l'Egypte,' and Merrem's name was merely the Latin rendering 
of the French " U A game variable ou Le Changeant," the term under which it appeared 
in the plates of the foregoing work. The lizard represented on the plate in question 
has the fourth digit longer than all the others, so that there is no ground for the 
supposition that it could possibly have been a drawing made from an individual of the 
species afterwards described by Heyden as A. sinaita ; moreover, Is. Geoffroy, in his 
description of I'Agame variable, clearly indicated the nature of its fingers, as he says, 
" les doigts vont en augmentant de longueur, a partir du premier jusqu'au quatrieme." 
In A. sinaita, on the other hand, the fourth finger, so far from being the longest, is 
markedly shorter than the third. 
The lizard figured by Is. Geoffroy corresponds to the individual (fig. 3) represented 
on Plate IX. of this work; whereas A. sinaita, Heyden (PI. X. fig. 1), differs from it 
in its much longer limbs and in the proportions of its third and fourth digits to one 
another. 
Is. Geoffroy described the scales of his lizard as being for the most part very small, 
and those on the back so fine as to be hardly distinguishable without the aid of a hand- 
lens, or at least only by the greatest attention. He also says that, although the scales 
are disposed as in the ordinary species of the genus Agama, I'Agame variable, unlike 
them, has no spines scattered over different parts of the body and none around the 
ear-opening or on the sides of the neck. 
The only lizard in the British Museum which at all approaches Is. Geoffroy 
St.-Hilaire's description of VAgame variable is a lizard from Egypt, presented many 
years ago to that institution by Sir J. Gardner Wilkinson. Dr. Gray regarded it as an 
example of " The Variable Trapelus," but placed along with it two other lizards from 
the same donor, which are undoubted examples of A. pallida, Keuss. Moreover, he 
regarded VAgame variable as identical with A. ruderata, Olivier. 
