OCR Text |
Show 1906.] IN MEXICAN LIZARDS. 351 original mid-field is pale greenish, without any spots.-This specimen has obviously entered the monochrome-stage on the anterior half of the body; a feature not uncommon in exceptionally large specimens of various kinds of Cnemidophorus. Two specimens from Manzanillo, the harbour of Colima.-Both are remarkable for the smaller scales which compose the principal row of the collar, the edge of which is formed by several complete rows of small granules. One specimen has 4/4 supraoculars, followed by several rows of small granules behind; in the other the 4th left supraocular is tiny, whilst on the right side the 4th or posterior is split into two. This is interesting because it represents a condition leading to the 3/3 supraoculars which are normal in G. immutabilis and deppei, in either of which, however, about 10 percent, show a fourth supraocular as abnormal. In the larger Manzanillo specimen (text fig. 78 C) the sides of the whitish collar are lead-coloured; on the back are 7 bluish-white stripes, each broken up into a row of paler spots connected by duller portions. Besides a series of larger irregular spots below stripe 1, there are no whitish spots in any of the fields except a few spots in field I. The ground-colour of the .back and of the thighs and upper surface is uniform dark blue-grey. The smaller specimen (text-fig. 78 A ) has 6 clear bluish-white stripes running from head to rump, and a short central stripe from head to mid-back partly dissolved into whitish mottlings. The fields are all uniform blackish without any trace of spots. These two Manzanillo specimens are consequently very much like C. immutabilis, from which they differ only by the possession of polygones or scutes on the posterior side of the forearm. One might be inclined to assume that in this coastal district of Colima the transition from C. immutabilis into C. communis copei takes place ; just as much as in certain parts of Oaxaca there are large Cnemidophori which might be interpreted either as the most aberrant clans of G. communis trending towards C. bocourti and G. mexicanus, or as aberrant C. immutabilis and guttatus, which assume characters typical of C. communis. Such are the C. communis var. australis. But to return to these Manzanillo specimens. Although the whole stretch of lowland from Manzanillo to Acapulco, a distance of 350 miles, is zoologically unknown, the fact remains for the present that the nearest bona fide specimens of G. immutabilis were found more than that distance away from Manzanillo, namely by myself still further east of Acapulco. I do not doubt that they extend much further west along the coast, but I also know that the lower Balsas flows through a broad belt of dense forest of a size and type sufficient to exclude these lizards. Cope's statement that his C. communis occurs also at Cohan in Guatemala is as worthless as that of Bocourt that he had C. mexicanus from Salama in Guatemala. It is quite possible, . but until these specimens are critically examined comment is useless. W e know that quite a number of Reptiles and Amphibians |