CALLISAURUS, THE GRIDIRON-TAILED 

 LIZARD 



(Callisaurus ventralis) 



"SPEEDING like greased lightning" is hardly 

 a figurative expression when applied to that 

 active and agile saurian, the gridiron- tailed 

 lizard. Starting off at full speed, with his black 

 banded tail held in air "as if afraid to let it 

 touch the hot earth, " he scoots across the sand 

 as if "shot from a cannon/' None of our desert 

 lizards can move so fast nor can any run so far 

 without fatigue. To arouse one of these "sand- 

 lappers" from his seeming lethargy while at 

 rest, and get him going at full speed in front 

 of you, is an act always hugely productive of 

 pleasure. Generally they move in great circles, 

 but when on long, open stretches, where there 

 is scarcely trace of vegetation behind which to 

 hide, they run a straight course. Then it is that 

 you see them racing at their best. Some ob- 

 servers have ventured to assert that these swift 

 runners when excited will, in their anxiety for 



