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Show 356 DR. H. GADOW ON EVOLUTION [Mar. 20, Thus it has come to pass that some of these Cuicatlan specimens (those with very small 4th supraocular, small collar-scales, and granular edge, entirely granular forearm, and with only 6 femoral rows) have become so different from the typical G. communis of Colima, that nobody could or would refer them to G. communis, nor to any of the gularis-group at all, if the specimens of Lagunas and San Domingo were not knowrn. . The most reliable guide happens after all, in this case, to be the colour-pattern. It may well be asked why the Cuicatlan specimens should not be grouped in the immutabilis lot: but, first, the collar, when large, is of the unmistakable gidaris type; secondly, when the number of pores is decidedly high this feature is never associated, either in immutabilis or in guttatus, with three regular rows of femoral scales extending down to the knee; thirdly, the evolution of the pattern. Although in immutabilis and in guttatus the stripes break up into rows of spots, transverse bars are quite unknown, while again in C. mexicanus, of Oaxaca, in spite of its tiger-bars, this mode of breaking up the stripes and the appearance of new white spots in their place are equally unknown. Consequently it is not due to chance that the Laguna- Cuicatlan specimens are considered as of the C. communis stock, modified in the direction of the typical Tierra caliente species C. immutabilis and guttatus. In short the var. australis, although in many respects intermediate, is not a true link between the gularis-communis and the immutabilis-deppei groups, but is the terminal outlier of the former. CNEMIDOPHORUS COMMUNIS BOCOURTI Blgr. (Text-fig. 80.) Diagnosis.-4 supraoculars. Collar composed of large scales, which form the edge. Humerals 6 ; femorals 5 to 6. Posterior side of forearm with some large polygones or scutes. Pores 15-18. About 12 rows of small yellow spots on red-brown ground-colour. Length about 100 m m . Oaxaca. Unfortunately the three type-specimens in the British Museum are without satisfactory localities. One is from " Mexico," the others were got by " Gumming, California," a locality which may safely be dismissed as erroneous. In 1902 I caught three specimens in the outskirts of the town of Oaxaca, indistinguishable from the types of this well-marked lizard. Boulenger gives the number of femoral rows as 8 or 9, but according to the plan adopted throughout this paper, i. e. counting from the row nearest the pores to the largest row on the anterior side of the thigh and not beyond, there are only 6 or 5 rows. Throat and collar are pale with a greenish tinge; rest of under parts, including thighs, blue-black, mottled with bluish-white scales. General colour above warm reddish brown, turning into olive towards the shoulders and the neck; with numerous yellow, small, and sharply defined spots, which are arranged in about 12-14 longitudinal rows. These spots are most numerous on the rump, extending also upon the root of the tail and over the |