DRAINAGE OF SOUTHERN INDIANA 181 
If the preglacial drainage of southern Ohio and southeastern 
Indiana (the eastern area, of the present discussion) was toward 
the north and east, as some writers believe, then the watershed 
between such northeastward drainage and the southwestward 
drainage of Indiana was the highland formed by the Niagara 
and Devonian limestones, 7. ¢., the present watershed between 
the eastern and central drainage areas of southern Indiana. 
How far north this watershed may have extended cannot be 
conjectured, but it probably extended as far north as Clinton 
county, and east of that county. 
3. It is believed that that portion of the state in which the 
preglacial topography and structure were similar to the present 
topography and structure of the driftless area had also preglacial 
drainage systems parallel in a general way with the present 
drainage systems of the driftless region. This includes most of 
that portion of the state which lies west of the southwestward 
dipping Niagara and Devonian limestones.’ 
(By ‘‘driftless region” is here meant that region in which it 
is obvious that the present drainage systems are not controlled 
primarily by the drift.) 
J. F. Newsom. 
STANFORD UNIVERSITY, 
California. 
*The drainage through the north end of the central area , or trough —z. e., in the 
region of Clinton county and northward from there — may have been toward the north- 
west, so far as the structure is concerned. 
