20S THE REPTILES OP EGYPT. 
CHALCIDES. 
Chalcides, part., Laur. Syn. Rept. 1768, p. 64. 
Body much elongate, rounded or angular. Limbs short or rudimentary ; digits 5 — 5 
to 1 — 1 ; nostrils formed by an emargination of the rostral and by a small nasal ; 
supranasals present. Eye well developed or small ; lower eyelid with au undivided 
transparent disk. Ear open, nearly hidden by the scales or fringed. Prefrontals and 
frontoparietals absent. Palatine bones separated on the mesial line of the palate. 
Palate toothless. Teeth conical. 
Mr. Boulenger has grouped under the genus Chalcides a number of species of 
lizards evidently generically identical, but still manifesting among themselves certain 
modifications in the form of the head, length and character of the body, degree of 
development of the ear, eye, and limbs, that are full of interest. 
In their habits of life they belong to two sections, one living among and under 
stones and amid herbage, and the other burrowing amid loose sand. The first of these 
sections contains the following species, viz. : C. ocellatus, C. viridanus, C. bedriagce, 
C. lineatus, C. tridactylus, C. guentheri, C. mionecton, and C. mauritanicus ; and the 
second C. sphenopsiformis, C. delislii, C. sepoides, and C. loulengeri. 
There can be no doubt of the intimate relation subsisting between C. ocellatus, 
C. viridanus, and C. bedriagce, as they have all similarly formed heads, large ear-orifices, 
moderately elongate rounded bodies, and almost equally developed pentadactyle limbs. 
The three species, C. lineatus, C. tridactylus, and C. guentheri, on the other hand, while 
they have similarly formed heads and large ear-openings like the previous group, have 
much more elongate and serpentine bodies, but still round, whilst they usually possess 
more feeble tridactyle limbs, reduced in the most specialized form, C. guentheri, to 
seemingly functionless knobs. 
From the structural features of these lizards, it is evident that they are in no sense 
burrowers. Their conical snouts, widely open ears, and relatively weak limbs are not 
suited to such a habit. 
In the third group, the members of which live in loose sand and whose bodies 
are specially adapted for such a life — viz. : C, sphenopsiformis, C. delislii, C. sepoides, 
and C. loulengeri — the head is modified, as the canthus rostralis disappears, the 
snout becomes wedge-shaped and projects beyond the labial margin as a sharp 
edge, and is thus well adapted for being driven into the loose sand, like the snout 
of Scincus. The eye becomes reduced in size, and also the ear, which is either 
almost hidden by the neck-scales or protected by a fringe of scales. The outline 
of the body also is modified, as it is angular at the sides. The limbs in all are weak, 
but more especially the fore limb. In one the fore limb is didactyle (Anisoterma, 
A. Dum.), in another tridactyle (Allodactylus, Lataste), and in other two tetra- or 
