1906.] IN MEXICAN LIZARDS. 345 



many, about 10 or more, rows of whitish-blue spots, especially 

 numerous on the lower back, rump, and thighs, upon a very dark 

 ground. In large and old specimens the ground-colour becomes 

 olive -grey, with bold transverse black tiger -bars across the 

 middle of the trunk ; the white stripes and spots having changed 

 completely into grey. The black pigment encroaches upon the 

 breaking-up stripes, and the neck of some old specimens tends to 

 become monochrome. 



There is no doubt that this clan of rather large-sized Lizards 

 conforms more with C. g. communis than with C c. balsas. It 

 is all the more interesting that these Puebla lizards come to 

 resemble the more or less tiger-barred specimens of C. c. balsas 

 (which are probably their neighbours) if they pass beyond the 

 white-spotted stage. 



PatzGuaro (text-fig. 77 B), south-west of Morelia, in Michoacan. 

 — The smallest specimen with 6 complete stripes and a broad 

 mottled mid-field. In the gravid female and in the adult male 

 the stripes are broken into streaks or numerous spots, bluish- 

 white and similar spots have appeared in the fields. Chest and 

 belly suffused with blue owing to the underlying dark pigment. 



Acambaro, north-east of Morelia. Only one immature speci- 

 men, collected by Dr. Meek. — Still with 6 very sharp, white 

 stripes ; pale spots just appearing in the outer and in the second 

 fields. 



Celaya, north of Acambaro, west of Queretaro : 4 specimens 

 collected by Dr. Meek ; largest about 75 mm. — With 6 whitish 

 stripes ; the younger specimens still without field-spots, but new 

 whitish spots appear in the older, still immature specimens ; 

 chest and belly blue, with white- edged scales. Throat and collar 

 white. 



San Juan del Rio. 3 specimens. Dr. Meek; 70-76 mm. 



QuanajiMto. 6 specimens in the British Museum, collected by 

 Dr. Dug^s, three of which only 48 to 50 mm. — These very young 

 forms have 6 very sharp white stripes and very dark spotless fields. 

 Faint pale brown spots in one row appear in the first and second 

 dark brown fields of the 62 mm. specimen. In the two 86-87 

 mm. specimens the field-spots ai^e white, very sharp and more 

 numerous ; and in one of these specimens numerous small white 

 specks have appeared within some of the three pairs of stripes, 

 which themselves have become dull. 



Unfortunately most of the specimens from Acambaro to 

 Guanajuato are young, or immature, whilst few, if any, are adult. 

 However, the fact of a gravid female from Patzcuaro seems to 

 indicate that all these lizards belong to a rather small race. The 

 breaking-up of the stripes into whitish spots, characteristic of 

 G. communis, is cleai'ly shown at Patzcuaro and at least in one 

 specimen from Guanajuato. It is impossible, with the present 

 material, to say whether the lizards of Acambaro, Oelaya, and 

 San Juan del Rio represent the transition from C. commu7iis to 

 0. mexicanus var. balsas, or whether they are potentially C. com- 



