94 THE KEPTILES OF EGYPT. 
become more strongly carinated and irregular. The most extreme example in this 
direction is found in specimens from the coast-line of the delta of the Nile. When I 
first met with it I provisionally regarded it as worthy of recognition as a distinct 
variety. Since then, however, my materials have increased, and in reviewing them, 
along with the specimens in the British Museum, I find that, although these deltaic 
specimens are at first sight strikingly dissimilar to typical A. mutabilis, the extremes 
are bridged over by intermediate variations. 
Lataste collected in the Algerian Sahara, at Hadjira, examples of this species, in 
which the dorsal scales are very markedly larger than those on the sides, so much so 
that they form a dorsal area by themselves ; but he also found at Tibremt, in the same 
region, others in which the dorsal scales are not sharply marked off from those on the 
sides, but some are larger than others, strongly keeled and mucronate. All of them 
approach the specimens from the littoral area of the Nile delta, and probably 
correspond to the lizards from the Algerian Sahara referred by Strauch 1 to A. ruderata, 
Olivier, and, possibly, are the equivalents of the lizards from the same region recently 
described by Dr. Franz Werner 2 as A. aspera. Specimens presenting the same 
characters as M. Lataste's Tibremt examples of the species were obtained by me 
some years ago at Biskra 3 . They had been collected between that health-resort and 
Tuggurt. From Duirat, on the Eastern Tunisian confines of the Algerian Sahara, 
my Arab collector brought back almost similar specimens. The lizards from Benghazi, 
in Cyrenaica, and those from the oasis of Kufra, in the Sahara, collected by Gerard 
Rohlfs and Dr. A. Stecker, and recorded by Peters 4 under the name of A. ruderata, 
are doubtless examples of this species. 
Agama mutabilis, Merrem. (Plate IX.) 
L'Agame variable ou Le Changeant, Is. Geoffr. St.-Hil. Descr. de l'figypte, Hist. Nat. i.? 1827, 
pp. 127-129, pi. 5. figs. 3 & 4; Cuv. Reg. An. 1817, p. 35. 
Agama mutabilis, Merrem, Tent. Syst. Amph. 1820, p. 50; Is. Geoffr. St.-Hil. I.e. pp. 127-129; 
part., D. & B. iv. 1837, p. 505 ; part., Riipp. Mus. Senck. iii. 1845, p. 302; ? Gasco, Viagg. 
Egitto, pt. 2, 1876, p. 106; Lataste, Le Natur. 1880, p. 325; Anderson, Herp. Arabia & 
Egypt, 1896, p. 100. 
? Agama deserti, Licht. Doubl. Berl. Mus. 1823, p. 101. 
Trapelus cegyptius, Cuv. Reg. An. nouv. ed. ii. 1829, p. 37. 
Agama inermis, Reuss, Mus. Senck. i. 1834, p. 33; Blgr. Cat. Liz. B. M. i. 1885, p. 344; Trans. 
1 Op. cit. p. 29. 
2 Zool. Anz. no. 429 (1893), p. 359. Daudin had already used this term for a South-African Agama. 
1 observe that Professor Boettger refers one of Dr. Werner's Algerian Sahara specimens to A. inermis 
(Kat. Rept. Mus. Senck. 1893, p. 49). 
3 Proc. Zool. Soc. 1892, p. 11. 4 Monatsb. Berl. Ak. 1880, p. 307. 
