12. SCELOPORUS 363 



Canyon, and Cave Creek in the Chiricahua Mountains, 

 Apache, Bisbee, Fairbank, Fort Huachuca, and Ramsey, 

 Ash, Carr, and Miller canyons in the Huachuca Mountains), 

 Santa Cruz (Nogales, Patagonia Mountains, Fort Critten- 

 den, Santa Rita Mountains in Agua Caliente Canyon, Gard- 

 ner Canyon, vicinity of Pete Mountain, and at Young's 

 Ranch), Pima (Tucson, Puebla Viejo, Fort Lowell, Tuc- 

 son Mountains, Catalina Mountains from foothills to 8,500 

 feet, Santa Rita Mountains in Sawmill, Stone Cabin and 

 Madera canyons, and Baboquivari Mountains), and Pinal 

 (Oracle), counties. 



In Sonora, this species has been collected 32 miles south 

 of Nogales, and at San Pedro Bay, as well as on Tiburon 

 and San Pedro Nolasco islands. 



Habits. This species is said to be more sluggish and 

 fearless than S. magister. At Oracle we found these lizards 

 in cracks in the granite boulders. The one from Mt. Lem- 

 mon was also taken on a boulder. Nearly all the others 

 were found on trees at Tucson on willows along the Santa 

 Cruz River, in the foothills of the Catalinas on mesquites, 

 in the Huachucas and Chiricahuas on oaks and pines. Those 

 taken at Fairbank were under the eaves of an old adobe 

 barn. They sometimes climb trees to a height of 30 or 40 

 feet, as observed from a bridge in Tucson. 



Ruthven states: "In contrast to S. magister, which oc- 

 curs on the plains, the habitat of S. clarkii is limited to the 

 timber zone along the streams (Willow-Poplar association), 

 and in harmony with the different conditions under which 

 it lives its habits also differ from those of the desert form. 

 It is found only on or near trees, and when surprised does 

 not dash down a hole as would S. magister under the same 

 circumstances, but up and around the trunk, keeping on the 

 far side of the tree like a squirrel. It is thus more arboreal 



