350 University of California Publications in Zoology. [Vol. 7 



on the flats of the open desert, three specimens were secured on 

 a rocky butte north of Quinn River Crossing. 



The above table shows 8. graciosus to possess the wider alti- 

 tudinal range, S. biseriatus being, for the most part, confined to 

 a narrow strip along the lower slopes of the foothills. 



At Quinn River Crossing several specimens of S. graciosus 

 were taken in mouse traps. 



Those stretches of desert seem to be preferred where sage- 

 brush {Artemisia tridentata) grows very thickly, although moun- 

 tain lizards are occasionally to be found on more open sandy 

 washes. 



Habits. — They were rather commonly observed climbing 

 about among the branches of the sage. When pursued they often 

 attempted to escape in this way. Ordinarily, when surprised, 

 they moved with great rapidity to -the shelter of a bush, on the 

 ground under which they remained motionless, until the collector 

 came into the near vicinity. Then they retreated into the thicker 

 brush or disappeared into some convenient burrow. Although 

 in the open the lizards were very shy, when they were in the 

 shelter of the brush one could approach them closely. 



Two females containing eggs were taken at Quinn River 

 Crossing May 21, one at Big Creek Ranch June 18, and another 

 at 4800 feet on Big Creek June 25. 



Crotaphytus tuislizenii is doubtless one of their chief enemies. 

 One of the leopard lizards taken contained the partly digested 

 remains of a Sceloporus graciosus. 



Sceloporus biseriatus Hallowell 

 Rock Lizard 



Distribution. — Quite common at Big Creek Ranch, but rare 

 at Quinn River Crossing. To enumerate stations at which spec- 

 imens were collected: Quinn River Crossing (4100 feet), 3; 

 Virgin Valley (5000 feet), 2; Limestones (near Dike colony, 

 south of Big Creek Ranch) , Pine Forest Mountains, 1 ; Big Creek 

 Ranch (4350 feet), 38. 



Van Denburgh (1897, p. 83) calls attention to the fact that 



