80 



MR. E. G. BOULENGER ON SOME 



liovvever, a veiy distinct species, quite different from the nume- 

 I'ous forms of C. ocellatus *. In its shorter not so unequal toes, in 

 its large ear-opening, and in its long, thick tail, it approaches the 

 gi'oups including C. Uneatus, ir {(1(1012/111,8, giientheri ; and my 

 father has given it as his opinion, that, although derived from the 

 same stock as G. ocellatus, it represents one of the pentadactyle 

 foi'ms from which the more degenei'ate types refei'red to above 

 have been evolved ; whilst a continuous degeneration can be traced 

 I'rom C. ocellatus through C. sepoides to C delislii and C mauri- 

 tanicus. 



In all, therefore, we now have, apart from the typical form, 

 seven varieties of the lizard G. ocellatus, and it is interesting 

 from the evolutionary point of vieAV that they axe geographically 

 connected, it being possible to trace every link in the chain from 

 tlie short and stout variety with as many as 40 scales from 

 Morocco, which must be regarded as the most generalized form, 

 to the long and slender type with only 22 scales round the body 

 from Abyssinia and Somaliland. 



The general reduction in the number of scales takes place 

 as follows : — 



The following aj-e definitions of the 8 forms into which 

 C.' ocellatus may be divided : — 



1. Var. polylepis Blgr. 34-40 scales round the body, the two 



median dorsal rows not enlarged ; light brown above, with- 

 out ocelli, but with a round yellowish spot on each scale, 

 forming regular longitudinal series sometimes sepai^ited b}' 

 dark lines : young with vertical black-and-white bars on the 

 sides of the neck. Maximum length from snout to vent 

 155 mm. 



2. Var. occidentalis Stdr. 30-32 scales round the body, the two 



median dorsal rows not enlarged ; coloration as in the 

 preceding, but the j^ellow spots less numerous. Maximum 

 length from snout to vent 100 mm. 



* C7i. hottegi var. tJiierri/i Tornier, Arch. f. Nat. 1901, p. 87. 

 Ch. tJiie7-)-i/i 0. Neumann, Zool. Jalivb., Syst. xxii. 1905, p. 401. 

 CIi. pulchellus Mocquard, Bull. Mus. 1906, p. 466. 



