EXPLANATION OF PLATE 13. 
Fig. 1.—Sand dune. This view illustrates one of the recent sand dunes 
near Mayport, at the mouth of the St. Johns River. 
Fig. 2.—Ancient sand dune. This view is taken at the crossing of the 
public road across the dunes, about two miles west of Daytona. The dune 
here consists of light colored sand to a depth of four or five feet, under¬ 
laid by ochre yellow sands. 
Fig. 3 .— Clay soil. Exposure at Saw Pit Landing on the St. Marys 
River, in Nassau County. The soil here is a sticky clay soil residual from 
the decay of the clayey limestone. 
