162 THE REPTILES OF EGYPT. 
Snout more or less pointed, longer in some than in others ; four supraocular shields, 
the first generally entire, but occasionally showing a slight tendency to division ; fourth 
usually broken up into two or more separate portions posteriorly, with a group of 
granules intervening between them and the third supraocular ; a line of granules 
separating these shields from the superciliaries which are generally seven in number ; 
subocular broadly excluded from the labial margin, having below it the fourth, fifth, 
and sixth labials, the fifth and sixth being much smaller than the fourth ; temporals more 
or less conical, somewhat elongate, and feebly keeled. Generally four to six denticles 
in front of the ear, varying in size, sometimes very small, and occasionally absent. 
Dorsal scales variable, smallest on the nape, largest between the thighs, smooth or 
carinated, more or less rhomboidal, and slightly imbricate or granular, sharply marked off 
from the larger caudal scales. Ventrals 14 to 18 across the middle of the belly, 14 the 
prevailing number ; nearly square, arranged in longitudinal and transverse rows, the 
halves of a transverse series meeting at a slight angle in the mesial line ; the ventrals 
pass insensibly into the scales on the sides. Collar perfectly free all round. Generally 
a large prseanal, with some enlarged plates lying in front of it, but sometimes broken 
up. Limbs well developed ; hind limb reaching either to the shoulder or to the ear. 
Digits of the fore limb with four rows of scales, 1 superior, 1 inferior, and 1 on each 
side ; and those of the hind limb with only three rows, viz. a dorso-lateral, a lower row, 
and one along the external borders of the digits : both sides of the fingers are fringed, 
but only the external borders of the toes ; the lateral scales of the former constitute the 
fringe, and the external row of scales of the latter the strongly curved denticles of 
the hind foot, better developed than in any other species. The plates on the under 
surface of the digits have an obtuse mesial keel. The claws are long and but little 
curved. Length of the tail variable, sometimes slightly exceeding twice the length of 
the head and body, but generally shorter ; upper caudal scales strongly keeled, those on 
the under surface of the base smooth, but the remainder more or less keeled. 14 to 
27 femoral pores. 
Colour bluish green or greyish, yellowish or pale buff, more or less covered with 
dusky reticulations enclosing pale spots, but occasionally nearly obsolete in yellowish 
and buff-coloured specimens which are sometimes finely black-spotted. The reticu- 
lations occasionally assume the form of short transverse black wavy lines, while in 
others they become broken up into spots. In some, there is a dusky line from behind 
the ear along the side, sometimes becoming bluish between the limbs ; and indications 
of dusky longitudinal lines may be present on the hinder part of the body, prolonged 
more or less along the sides of the tail. The throat occasionally suffused with bluish 
green. The limbs, especially the hinder limbs, reticulately marked and spotted. 
Underparts white. The young is spotted with white, which may or may not assume 
the form of longitudinal lines. 
