E. W. Hilgard on the Quaternary of Mississippi. 315 
the northern Drift, the differences being quantitative rather than 
qualitative—its age later than the latest Tertiary, yet anterior to 
] 
to the extent of characteristic feature, of limited deposits of fer- 
of the Drift itself, in Mississippi its action has frequently ex- 
tended beyond the Orange Sand, into the underlying formations, 
