154 THE EEPTILES OF EGYPT. 
from between Biskra and Tuggurt. In six of these cases, however, it exists only on 
one side of the head. 
A supplementary upper labial is also met with in specimens of A. vulgaris, both in 
Africa (Tangiers) and in Europe (Abrantes, Portugal), and likewise in A. scutellatus. 
The denticles of the ear are subject to much variation, being well developed in some 
and practically absent in others. 
From the table that follows (pp. 158-160) it will be seen that although there is a 
difference of 29 between the lowest and highest number of scales, in the totality of the 
specimens tabulated, no such disparity is ever met with in any one locality. In Somali- 
land the variation is 16, in Palestine 6, in the Maryut District, Egypt, 19, in Tripoli 
and Tunisia 16, on the plateau of Algeria and the Aures Mountains 16, and in the 
Sahara 16. The highest numbers in these localities are respectively 78, 80, 81, 72, 85, 
and 77. The specimens from Tripoli and Duirat belong to the small form of this 
lizard from the Sahara described by Gunther as Zootoca deserti, while those from 
Batna, that is from the high plateau of Algeria, and from the Aures Mountains attain 
to the greatest size of all (76 millim. from snout to vent), and are somewhat heavier 
built than those from Tunisia, Egypt, Palestine, and Somaliland, but the difference in 
relative size of these lizards from these localities is not great. Saharian specimens 
of Zootoca deserti attain to 65 millim. from snout to vent, whereas the largest male 
from the Maryut District is only 3 millim. longer ; the largest specimen of the same 
sex from Palestine is 71, from Somaliland 74, and from the plateau of Algeria 76 millim. 
It is thus evident that the somewhat smaller Saharian lizards by their largest indi- 
viduals, 65 millim., lead into the Egyptian lizards and into those of the Tell of Algeria. 
As pointed out by Lataste, the proportions of those from the high plateau of Algeria, 
and I may also add from the Aures Mountains, are sometimes even heavier than those 
of A. vulgaris, so that when these large forms and those from Egypt and Palestine 
are compared with the Saharian lizards the difference may appear considerable, but it 
is only one of degree. 
The scales are generally almost granular, but in some specimens they are rhomboidal, 
larger, and more flattened than granules. These two modifications may either be 
smooth or more or less carinate, and this may be the case among individuals of the 
same sex from the same locality. In the larger of the two specimens from Tripoli, a 
gravid female (53 millim. from snout to vent), the dorsal scales are smooth or almost 
so to the base of the tail, but in the young female over a considerable part of the 
hinder half of the back they are distinctly keeled, and on the dorsum of the tail are 
strongly so, while in the larger specimen the caudal keels are not quite so markedly 
carinate. 
In the lizards found at Maryut and in Palestine the dorsal scales are smooth, but in 
a specimen from Egypt, in the Paris Museum, they are strongly keeled and imbricate, 
which is also the case in specimens from Somaliland and Algeria. 
