1906.] IN MEXICAN LIZAKDS. 351 



original mid-field is pale greenisli, without any spots. — This speci- 

 men has obviously entered the monochrome stage on tlie anteiior 

 half of the body ; a feature not uncommon in exceptionally lai-ge 

 specimens of various kinds of Gnemidophorus. 



Two sjjecimens from Manzanillo, the ha.i'bour of Oolima. — 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 supraoculai-s, 

 followed by several rows of small granides 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. iinmutahilis and deppei, in either of which, however, 

 about 1 per cent, show a fourth supraoculai' as abnormal. 



In the larger Manzanillo specimen (text fig. 78 0) the sides of 

 the whitish collar are lead-coloured ; on the back are 7 bluish- 

 white sti-ipes, 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 groiuid-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, aiid a shoi't central stiipe 

 from head to mid-back partly dissolved into whitish mottlings. 

 The fields are all uniform blackish without any tra,ce of spots. 



These two Manzanillo specimens are consequently very much 

 like G. immntahilis, from which they differ only by the possession 

 of polygenes or scutes on the posterior side of the forearm. 



One might be inclined to assume that in this coastal district 

 of Oolima the transition fi-om G. immutahilis into G. communis 

 copei takes place ; just as much as in certain parts of Oaxaca 

 there are large Cnemido})hori which might be interpi'eted eithei- 

 as the most aberrant clans of G. communis trending towards 

 G. hocourti and G. mexiccmios, or as aberrant G. immutabilis and 

 guttahis, which assume characters typical of G. comm.unis. Such 

 are the G. 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. ionmutabilis 

 were found more than that distance away from Manzanillo, 

 nainely 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 sufiicient to exclude these lizards. 



Cope's statement that his G. communis occurs also at Coban in 

 C4uatemala is as worthless as that of Bocourt that he had 

 G. mexicanus from Salama in Guatemala. It is quite possible, 

 but until these specimens are critically examined comment is use- 

 less. We know that quite a number of Reptiles and Amphibians 



