CHALCIDES. 209 
pentadactyle (Sphcenops, Wagler) ; the hind limb in all is generally tetradactyle, and in 
one species occasionally pentadactyle. 
The two species grouped along with C. ocellatus conform, more or less, to its type 
of coloration ; whereas in the second group lineation of the body is the characteristic 
feature, a type of coloration which is also present in the third, but associated with a 
pale body colour, in keeping with the sand in which the lizards live. 
The lizard described by Professor Boettger from West Africa under the name of 
Seps (Gongyloseps) mionecton, manifests a perceptible tendency, in the more rounded 
character of the canthus rostralis and in the greater flattening of the symphysis 
of the lower jaw, to lead into the third group. The ear also is open, but smaller 
than in C. bedriagw, to which it is closely allied, and from which it differs in having 
more degraded limbs and in some other characters. Its body is more elongate than 
in C. viridanus, and slightly more so than in C. bedriagce. Its colour is almost exactly 
similar to that of the latter, and retains like it the undoubted equivalents of the 
ocellation of C. ocellatus, but restricted chiefly to the brown area occupying the 
middle of the back and to the tail. C. mionecton leads not only to the third group, 
but also somewhat towards C. tridactylus. The great gaps, however, that exist between 
the species may eventually be more or less filled up by intermediate forms, when the 
region of Africa to the south and east of Morocco becomes known. The condition of 
the ear of C. mionecton is of considerable interest, as the upper scales of the orifice tend 
to form a fringe over it, but it is no more than the beginning of a divergence from the 
type of ear characteristic of the first and second groups towards that distinctive of 
the third group, and most accentuated in the fringed ear of C. sepoides. In C. delislii 
and C. sphenopsiformis the ear is more hidden, as the scales all but wholly cover it, 
but they are not modified into a fringe as in C. sepoides and C, boulengeri. 
The form C. mauritanicus, Dum. & Bibr., is closely allied to C. mionecton, as the 
body is round and has about the same degree of elongation, and much the same colour. 
The head has the form of the head of C. viridanus, but the limbs are even more 
degraded than in C. mionecton, and there are only two digits anteriorly and three on 
the hind limb. The ear is almost entirely covered by the scales. There are only 10 rows 
of scales round the body, which is the smallest known number in this genus of scinks. 
It is doubtless an offshoot from C. mionecton, like the other small sand-lizards, such as 
C. boulengeri and C. sepoides on the one hand, and C. delislii and C. sphenopsiformis on 
the other; whereas the large-eared scinks of this genus, viz. C. lineatus, C. tridactylus 1 , 
and C. guentheri, are in all likelihood offshoots from an ancestor allied to C. bedriagce, 
and from which C. viridanus and C. ocellatus also probably sprang. 
1 Chalcides tridactylus, Laur. 
Chalcides tridactyla, Laur. Syn. Kept. 1768, p. 64. 
Chalcides tridactylus, Blgr. Cat. Liz. B. M. iii. 1887, p. 403. 
A scink has been recorded from the neighbourhood of Alexandria by Prof. Gasco * under this name. Iu 
* Viagg. in Egitto, pt. ii. 1876, p. 109. 
2 E 
