SNAKES OF THE GENUS PITUOPHIS 



175 



a ground squirrel, Citellus mollis." Another was taken "under a 

 small sagebrush not far from a river bank. It contained large eggs 

 (July 9)." 



Region No. 12 3 4 5 6 



FiQUKE 78.— Geographic variation in total number of dorsal spots in Pituophis catenifer deserticola. 



Ruthven (1915, p. 952) says that the form is found "in apparently 

 equal abundance in the mountains and on the basin floor," and is 

 "equally at home in all habitats, regardless of the soil or the presence 

 of rocks," 



