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Show 326 DR. H. GADOW ON EVOLUTION [Mar. 20, priority of name; genetically it is the terminus of a series which begins with the entirely striped race : II. C. immutabilis of Cope. By irony of fate this is the proper name of one of the most variable of lizards. It is what I called C. guttatus var. striata in Proc. R. S. 1903. Cope's types came from " West of Tehuantepec." The characteristic feature of this brighter-coloured race is the 6 to 8 continuous white stripes on a rather uniform and dark ground. Such typically striped specimens are now known from San Mateo del Mar, Salina Cruz, Tequesixtlan, Cocoyul and Pacific Coast east of Acapulco, Miahuichan, and southern slope of Los Cajones. In general terms: the coast region of the States of Oaxaca and Guerrero; how much further west along the Pacific Coast remains at present unknown. I have found it exceedingly difficult to keep free from bias whilst assorting these very variable lizards according to the prevalence of either stripes or spots, and still more difficult clearly to pronounce upon the physical features of their localities. However, I can affirm the result that in the small open localities the striped lizards prevail, almost to the exclusion of more than two rows of spots ; while in places with many shrubs, much underwood, absence of large grassy and sandy patches, the spotted forms prevail, in the more typical bush forests of the Atlantic side almost to the exclusion of stripes. Open localities, either strips near the sea-shore, sandy beds of frequently dry rivers, grassy stretches with scanty trees, and nowhere covered during half the year with rank and dense herbaceous growth, were the collecting spots of Cocoyul, Salina Cruz, San Mateo, Tequesixtlan, San Domingo de Guzman; also Miahuichan, a spot on higher ground and just above the luxurious tropical growth of forests; likewise the open grassy slopes near Rincon at the southern slope of Los Cajones, amongst scanty pine-forests. Much tangled underw'ood, broken terrain, wTell wTooded ravines, or meadows with tall grass and herbs, or rivers fringed with masses of shrubs, were the features of Tierra Colorada, Ayutla, and San Luis Allende; those very spots wmich yielded the most intermediate specimens. In the Atlantic Tierra caliente, with its decidedly denser vegetation, with fewer deciduous trees, and much greater annual rainful, the typical C. guttatus alone is found, for instance at Agua fria, San Juan Evangelista, La Antigua (V.C.). Of course there are many and large Savannahs in the lower coast-districts of the State of Vera Cruz, and it would be interesting to ascertain whether any large Cnemidophori occur in the open Savannah, and not only in the vicinity of the typical clusters or patches of trees. Personally I have but little experience of these parts. All I can affirm is that I have seen no Cnemidophorus near Tetela, only C. guttatus at Agua fria, the same form and C. deppei at San Juan Evangelista |