E. W. Hilgard on the Quaternary of Mississippi. 31° 
turn, are most unequivocally connected with the Orange Sand of 
Mississippi. With the latter formation he was acquainted only 
th 
or of the existence of the great delta whose apex reaches the 
mey’s 
they would not transport any materials beyond it; those oe 
the Drift of the eastern cotton states must, of necessity, be deriv 
from the southern slopes of that barrier itself, as Tuomey states is 
the case in Alabama, and as I have found it to be in the eastern, 
and smaller, pebble belt of the Orange Sand delta in Mississippi. 
t where, as in the main channel of the Mississippi, those wa- 
ters might rush southward unchecked, through the gap between 
’ the Alleghany and Ozark upheavals, we might expect to find 
traces of rocks derived from higher latitudes. Such are fur- 
