.MEMOIRS CXIV. ('AUK.. VOL. 1. NO. '2 



MEBRIAM1 I'l.ATK 21 



Fig. 1. The locality at which the principal excavation work of the University of California has I n car- 

 ried on. The exposure to the left shows separation of distinct strata. The small white patches in the 

 asphalt represent weathered hones still in the original matrix. Photograph by Ralph Arnold. 



Fig. 2. A tar seep. The area in the middle of the seep is very soft. Toward the margins the surface 

 gradually hardens. 



