'EMHIRfi r.M.I^rm 'nn Vpt, yr. 



[ARiinLD] Plate yyr.^ 



Figure a. San Diego. — Bluff at foot of Twenty-sixth street, looking north, showing the fossiliferous 

 upper San Pedro (Pleistocene) deposits In the lower half of the bluff. The Anomia limatula bed is at the 

 very base of the bluff and forms the reefs at the right of the picture. 



Photograph by R. Arnold. 



Figure b. San Diego.— Small section of the sea-cliff at Pacific Beach, showir 

 Opalia varicostata in the matrix of the San Diego formation (Pliocene). 



expansus and 



Photograph by R. Arnold. 



