UNIV. CALIF, PUBL. ZOOL. VOL. 5 [GRINNELL] PLATE 20 
20a. Gopher snake ( Pituophis catenifer), taken near the mouth of the south fork of the Santa Ana 
July 3, 1907. 
20B. The same gopher snake as shown in the previous figure, photographed a few minutes later after 
having assumed a tetanic rigidity. 
