78 



MR. E. G. BOULENGER ON SOME 



long *. On examination of a large material since received at the 

 British Museum, I find that this form cannot be accepted as a 

 distinct species, the nostril being almost as often pierced above 

 the suture in question as in advance of it ; while in a number of 

 specimens of the typical (,/. ocellatus the nostril is pierced in 

 advance of the rostral and the first labial. The body of the form 

 hottegi is, I find, not always more slender than in the typical 

 C. ocellatus, in which there is considerable variation in this respect. 

 The number of scales, however, is less than in the typical 

 C. ocellatits, being as a rule 24, as in the var. ragazzii, but 

 dropping sometimes to 22. The degree of enlargement of the 

 two median rows of dorsal scales varies considerably both in the 

 form in question and in the typical C. ocellatus. If the position of 

 the nostril cannot in this genus be regarded as of specific value, 

 the question arises whether C. viridanus, which apart from this 

 character agrees so closely with C. ocellatus, must also be only 

 allowed the rank of a variety to be added to the numerous other 

 forms which are embraced in the specific conception of C. ocellatus. 

 I find, however, that the head has a different shape, the snout 

 being less convex — a difi'erence which finds expression in the 

 proportions of the upper labials, all or most of wdiich are not 

 deeper than long. 



There are two forms of C. viridanus — the typical, from Tenerife, 

 Gomera, and Hierro, with the sides and belly black and 26-32 

 (usually 28) series of scales : and the var. simonyi, from Gran 

 Canaria, with the belly yellow, greenish white or grey, the head 

 somewhat larger and better defined than in the preceding, and 

 28-34 series of scales. 



As pointed out by Steindachner, the Chalcides of Fuertaventura 

 must be regarded as a variety (var. occidentalis) of C. ocellatus'^. 



Great individual variation in form "is to be found in the 

 structure of these lizards, especially in the proportions of the 

 limbs and body. In the var. hottegi the latter may vary to a very 

 great extent, namely from 18 to 28 per cent. In the distance 

 ])etween the axilla and groin the variation is also often great. 

 The variations show that little importance can be attached to the 

 proportions of the body and limbs, there being an overlap, for 

 instance, in the length of the limbs between the two species 

 G. ocellatus and C. hedriagce. The latter lizard was described as 

 differing specificall}^ from C. ocellatus in the proportions of the 

 limbs, and in the nostril being pierced in advance of the suture 

 between the rostral and first labial. It has been shown that 

 neither of these characters can be regarded as absolute. I have 

 ascertained, however, that in C. bedriagce the fourth labial 

 normally takes the place of the subocular, and not the fifth, and 



* Boulenger. Ann. Mus. Genova (2) xviii. 1898, p. 719, pi. x. fig. 1, and (3) v. 

 1912, p. 330. 



t Lanzavote and Fuertaventura, waterless and treeless and nearer the African coast, 

 (litier greatly from tlie other Canary Islands in their fauna, which is nearly identical 

 with that of the neighbouring Sahara. — Tristram, Brit. Assoc. 1893. 



