354 BOTANICAL GAZETTE [NOVEMBER 
development of reentrant angles along its crest, as the great con- 
tinental ice sheet? became more and more differentiated into lobes 
during its retreat (52, 13). In northern Indiana it marks the first 
areas uncovered, as the mass of ice, pushed forward from the basin 
of Lake Michigan, separated from that originating in the Lake Huron 
and Lake Erie basins. 
When the Huron River basin was reached, the Saginaw lobe had 
been developed and lay over the northwestern part, while the Huron- 
Erie lobe covered all of the territory southeast of the interlobate 
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Fic. 2.—Map of southern Michigan, northern Indiana, and n 
showing “moraines with strong expression.” After LEVERETT, U. S. Geo 
Mon. 41, plate 2. The irregular dotted lines mark the 1000-foot (300) eel 
moraine. The first portion of our area to be uncovered is the triangt 
lar gravel outwash apron extending southwestward from Sugarl 
Knob. This was the beginning of the Huron River. Kavanaugh 
Lake then lay just under the edge of the Erie ice, and Crooked Lake 
uccupied a similar position on the southern border of the Saginaw 
lobe. As has been recently determined by Mr. FRANK LEVERETH 
of the U. S. Geological Survey, the subsequent history of the Huron 
drainage is most remarkable. rally 
The waters from the glacial drainage at first flowed gene rae 
westward, reaching the Kalamazoo River near Albion, thence . 
St. Joseph at Three Rivers. At South Bend, Indiana, it <r 
2 For general map see no. 55, p. 411. (Bibliography at close of this P si 
orthern Ohio, 
G fe 
