AGAMA SPINOSA. 117 
and strongly keeled, with ridges formed by the keels converging towards the mesial 
line of the back. 
The limbs and digits of A. bibronii are rather shorter than they are in the other 
species. In all the foregoing species the third and fourth toes are nearly equal, the 
latter being, as a rule, a little longer than the former. 
With the exception of A. spinosa, the males of the foregoing species have no distinct 
gular pouch, but the skin of the throat is much plicate. This plication is so 
pronounced in A. spinosa (PI. X. fig. 2) that it is entitled to be regarded as a short 
pouch. 
While A. bibronii is confined to North-western Africa (Morocco, Algeria, and 
Tunisia), the Western A. colonorum, Daud., extends right across the continent J to 
within 60 miles of the shores of the Gulf of Aden 2 ; and if A. cariniventris, Peters, 
is identical, as Dr. Tornier 3 says it is, with the lizards referred by Peters to A. colonorum, 
and if the latter, as understood by Peters, was the true A. colonorum, the distribution 
of this species ranges southwards on the eastern coast to Zanzibar. On the other 
hand, A. hartmanni, Peters, is known only from Abyssinia, Somaliland 4 , British East 
Africa 5 , German East Africa 6 , and Dongola in the Nile valley 7 . 
Besides the last-mentioned species, four others also with equal keeled scales, the 
lines of carination being convergent towards the mesial line of the back, and with the 
other features of A. colonorum, have been described from Abyssinia and Somaliland. 
They are A. rueppellii, Vaillant 8 , A. smithii, Blgr. 9 , A. lionotus, Blgr. 10 , and 
A. vaillanti, Blgr. 11 
The first of these is distinguished from all the others by its larger scales, of which 
there are only 48 round the middle of the body, and 26-34 12 , according to M. Mocquard, 
between the origin of the limbs along the mesial line of the back, those on the tail 
being still larger. Its head is short, recalling that of A. pallida, and the nostril 
resembles that of A. bibronii and A. hartmanni in being placed below the canthus 
rostralis. It is also closely allied to A. vaillanti, but differs from it in having a more 
elongate body, much larger scales, and a nuchal crest. It is, however, further affined 
1 Peters, Mon. Berl. Ak. 1862, p. 271 ; Stejneger (Smithsonian Inst. no. 970, 1893) ; Proc. U.S. Nat. 
Mus. xvi. 1894, p. 717. 
2 Blgr. Ann. & Mag. N. H. (6) xvi. 1895, p. 167. 3 Kriechthiere Deutsch-Ost-Afr. 1897, p. 29. 
4 Blgr. Ann. Mus. Civ. Genova, ser. 2, ii. 1885, p. 127 ; op. cit. xv. (xxxv.) 1895, p. 13 ; op. cit. xvii. 
(xxxvii.) 1896, p. 8 et p. 277 ; Proc. Zool. Soc. 1895, p. 533 ; op. cit. 1896, p. 214. 
5 Giinther, Proc. Zool. Soc. 1894, p. 86. 6 Op. cit. p. 29. 
7 Peters, Mon. Berl. Ak. 1869, p. 65. 
3 Bevoil, Paune et Flore des Pays Comalis, Kept. & Batr. 1882, p. 6, pi. i. 
9 Proc. Zool. Soc. 1896, p. 213, pi. vii. 10 L, c. p. 214, pi. viii. 
11 Ann. Mus. Civ. Genova, ser. 2, xv. (xxxv.) 1895, p. 12, pi. iii. fig. 2. 
12 Mem. Cent. Soc. Philom. 1888, p. 115*. 
