82 IOWA ACADEMY OF SCIENCES. 



There are traditions to the effect that since the arrival of 

 the white man, Wall lake was tributary to the Boyer river, 

 but for them there seems to be no basis other than the fact 

 that every one noting the conditions, even casually, must see 

 that it would require but a slight change in existing conditions 

 to so deflect the water. 



Other considerations which further study might remove 

 from the realm of mere speculation to that of reasonable cer- 

 tainty, would be as to whether this glacial river valley does 

 not represent the pre- Wisconsin course of the Boyer river. 

 The slight study given the question seems to show that north 

 of the Wall lake region the valley of Boyer river is younger 

 than the valley of the same stream farther sDuth. Th9 valley 

 of the 'Coon northeast of Wall lake suggests maturity, and a 

 study of the map forces th3 thought that the 'Coon river from 

 this point on represents the pre-Wisconsin Boyer river, which 

 was diverted and thrown over into a branch of the 'Coon, or 

 into the upper course of the 'Coon itself, by the Wisconsin 

 moraine. These points can be determined only by a more 

 careful study of the valleys of the streams, and the glacial 

 deposits of the vicinity. 



FORMATIONAL SYNONOMY OF THE COAL MEASURES 

 OF THE WESTERN INTERIOR BASIN. 



BY CHARLES R. KEYES. 



Of late years the Carboniferous terranes, or formations of 

 the Mississippi basin west of the great river have been widely 

 studied. They are now capable of being classified in detail. 



For a long time much confusion existed in regard to the 

 relations that the schemes of various investigators, and 

 especially those of the pioneers, bDre to one another, and to 

 the more modern widely correlated arrangement. The adjust- 

 ment of the results of all workers, extending over a period of 

 fifty years, in a field embracing the greater part of six states, 

 was fraught with many difiiculties. 



With the modern method of giving geographic names to the 

 terranes there has arisen a strong tendency to ignore the 

 work of the earlier investigators, and to inordinately multiply 

 titles. 



