70 REPTILES AND BATRACHIANS 



and covered with large broad spines. It is endowed, like 

 many other lizards, with the power of changing colour, 

 the blackish olive of its upper parts, which are marbled 

 with brick red, passing to a light blue. 



The genus Phrynosoma, the Horned Toads, as these 

 small, much flattened lizards are often called, inhabit the 

 Southern United States and Mexico ; they are covered 

 all over with spines, those at the back of the head being 

 specially developed. These spines are bony processes of 

 the skull, covered with horn, and not, as in the case of the 

 Moloch, merely hollow horny structures. The colour of 

 these creatures is usually grey or light brown, harmonizing, 

 in a remarkable manner with the sandy soil upon which 

 they are found. 



Dr. Stejneger, who has observed these lizards in their 

 natural environments, states that, in the cedar and pine 

 belts of the San Francisco mountain, the dark colour of 

 the soil and stones covering the surface is exactly matched 

 by the ground colour of the Phrynosomes, while the 

 greenish-grey or orange-coloured markings, which some- 

 what irregularly adorn their backs, are perfect imitations 

 of the lichens covering the rocks and pebbles among which 

 these odd-looking creatures live. Near the rim of the 

 Grand Canyon of the Colorado, where the ground is 

 covered with minute pebbles of coloured sandstone, which 

 ranges in colour from white to brick-red and dark brown, 

 the specimens are all faithful reproductions of their sur- 

 roundings. Most remarkable of all, however, are the 

 Horned Lizards of the black lava belt, which is situated 

 north-east of the mountain, for these are black above 

 with light markings of " Naples yellow," changing into 



