98 
THE EEPTILES OF EGYPT. 
to refer any of the foregoing lizards to A. ruderata, which differs from them in its 
convex snont, greater internasal breadth, and in the nostril being placed decidedly 
below the canthus rostralis, and thus more or less lateral in position. Its head-shields 
also are markedly different from those of the North- African lizards, as there are generally 
one or more ridges to each scale. 
Dr. Peters was of the opinion that A. ruderata was a form nearly allied to A. agilis, 
Olivier ; but he had doubtless before him not the true A. ruderata, but A. mutabilis, 
Merrem, because when he expressed this opinion he had only recently identified 
Messrs. Rohlfs and Stecker's specimen from Cyrenaica as A. ruderata. I have not 
met with a single lizard, either from Egypt or to the west of it, that can be referred to 
A. ruderata. The lizard mentioned under this name by Audouin is Agama pallida, 
Eeuss. The forms of A. mutabilis with a coarser lepidosis present a certain resemblance 
to lizards of the A. agilis group, and this has doubtless led to their having been 
occasionally referred to that species. 
Measurements &c. of 
A. mutabilis, Merr. (in 
millim.). 
6 
Snout 
3X. to 
vent. 
Tail. 
Length 
of 
Lead. 
Width 
of 
head. 
Length 
of fore 
limb. 
Length 
of hind 
limb. 
Tibia. 
Hind 
foot. 
Pores. 
Locality. 
S 
... 93 
125 
22-3 
22-2 
45 
61 
22 
23-1 
4 
Duirat. 
s 
... 87 
135 
19-6 
20-2 
44-4 
61 
23 
24-8 
Tunis. 
s 
.. 86 
108 
20-8 
20 
46-3 
60 
21-5 
24-5 
Duirat. 
s 
... 85 
114 
18-5 
18-5 
40-3 
55 
18 
22 
Tunis. 
d 
... 83 
115 
20 
20-3 
39 
60 
20-5 
23 
Karuleh. 
? 
... 83 
109 
18-1 
18 
43-8 
61 
20 
25 
7 
Duirat. 
c? 
... 80 
122 
19 
18-5 
41 
58 
20-2 
22 
8 
12 
Biskra to Tuggurt. 
c? 
... 79 
115 
20 
20 
41 
56 
19 
23 
7 
Bainleb. „ 
6 
... 79 
105 
20-5 
19 
44 
59 
19-3 
23 
3 
PL IX. fig. 4. 
6 
. . . . 78 
124 
19 
19-3 
41 
57-3 
20 
24-5 
11 
12 
Tibremt. 
2 
. . . . 78 
99 
19-5 
20 
40 
55 
18 
21-7 
9 
4 
11 
10 
4 
Algerian Sahara. 
<3 
. . . . 78 
99 
19-8 
19-4 
44 
58-5 
20 
24-5 
Egypt. 
9 
. . . . 78 
82 
18-6 
20 
45 
59 
18-6 
24 
Eayum. PI. IX. fig. 5. 
? 
. . . . 77 
18-6 
20 
40-5 
55 
17-6 
22-S 
Maryut district, Alexandria. 
1 
.... 76 
120 
17-5 
17-5 
40 
57-5 
20 
22-8 
10 
Tunis. 
