AcanthmladyJus. 53 



Tlie six forms here defined are not always easy to distinguish, 

 owini; to iutergradation. The followiug synopsis will help in their 

 identification. 



I. Scales in middle of body smooth or feebly keeled : if strongly keeled, convex ; 



tail of young red. 



Subocular not reaching the oral border, or entering it very 

 narrowly ; suture between the nasals i to i the length of 

 the frontonasal ......... Forma typica. 



Subocular largely bordering the mouth ; suture between the 

 nasals rarely more than i the length of the frontonasal 



Var. belli, Gray. 



Subocular separated from the oral border by a small shield 

 detached from it ; suture between the internafals i the 

 lengtli of the frontonasal ..... Var. atlajiticus, Blgr. 



II. Scales in middle of body flat, with strong, well-defined keels. 



Subocular bordering the mouth ; tail red in the young 



Var. mauritaniciis. Bou rn . 



Subocular usually not reaching the mouth ; prefrontals in 

 contact with each other ; tail blue in the young . Var. fcianct, Doum. 



Subocular usually not reaching the mouth ; prefrontals often 

 sepac ated by one or two shields ; frontonasal often divided 

 into two ; tail red in the young . . . Var. lineomaculatus, D & B. 



2. ACANTHODACTYLUS TRISTEAMI. 



.'' Sc(q>teira leiocerca, G-ray, Ann. N. H. i, lSo8, p. 281. 



Zootoca tristrami, Giinth. Proc. Zool. Soc. 1§64, p. 491 ; Tristram, 

 Faun. Palest, pi. xvi, fig. 2 (188-4). 



Acanihodactijliis dorsalis, Peters, Mou. Berl. Ac. 1869, p. 62. 



Acanfliodad ijJu/! tridrami, Bouleng. Proc. Zool. Soc. 1881, p. 746, 

 pi. Ixiv, fig. 1 ; Lataste, Ann. Mus. Genova (2) ii, 1885, p. 482 ; 

 Bouleng. Cat. Liz. iii, p. 68 (1887), and Bull. Soc. Zool. France, 1918, 

 p. 147. 



Laceda jilatyiini, Hempr. it Ehreuh. Symli. Phys., Zool., Amph. 

 pi. ii, fig. S (1899). 



Habit robust, body depressed. Head about 1} to IJ times as long 

 as broad, its length 4 to i^ times in length to vent, its depth equal to 

 the distance Isetweeu the anterior corner or the centre of the eye and 

 the tympanum ; a rather feeble concavity between the prefrontals and 

 along the anterior half of the frontal ; snout obtusely pointed, with 

 obtuse canthus and feebly concave loreal region ; nasals not or but 

 very feebly swollen. Pileus If to 2 times as long as broad. Neck as 

 broad as the head or a little broader. The hind limb reaches the axil 

 or the shoulder in males as in females ; foot 1,V to li^ times as long as 



