PLATE 20 



Fig. 2. High plain environment near volcanic plug at south end of Turtle 

 Mountains, San Bernardino County, California. Yucca moliavensis in foreground 

 and middle distance. 



Fig. 3. Low plaiu environment near Blythe Junction, Riverside County, 

 California. Dipodomys deserti burrows in foreground, sand dunes in distance. 



[•'40] 



