Osage vs. Augusta. — IVellcr. 13 
strata. In his investigations of the Lower Carboniferous 
faunas of the Mississippi valley Prof. H. S. Williams detected 
the records of three distinct chapters in the history of the con- 
tinental interior, and to the middle one of these chapters he 
gave the name of Osage, the rock strata containing the fossil 
records of the chapter being designated as the "Osage group." 
It was recognized that the faunas of the Burlington and Keo- 
kuk limestones were a unit in themselves to such an extent 
that they should not be divided into several distinct groups, 
as had generally been done by earlier geologists. There were 
life changes in progress during the time of deposition of these 
limestones, but they were internal, evolution changes, not de- 
pendent upon profound physical changes or upon the immi- 
gration of new forms of life. The records of the Osage chap- 
ter in our continental history were found to be best expressed 
in these faunas of the Burlington and Keokuk limestones. 
Mr. Keyes' contention that the Osage and Augusta are not 
synonymous, because Williams failed to include a portion of 
the so-called Warsaw group of older authors in his division, is 
based upon unessentials and is not tenable. On the same 
ground, if some future investigator were to find that a small 
portion of the Chouteau limestone would be better placed with 
the superjacent strata, it would be perfectly legitimate for him 
to ignore both the names Osage and Augusta, and to propose 
still a third, and so still further increase the confusion. 
As a matter of fact, Williams did recognize that one 
portion of the Warsaw faunas were of Osage age and another 
of St. Louis age; and he showed, before Mr. Keyes, that the 
fauna of the Warsaw group had no separate place in a natural 
classification of the Mississippian faunas. He says:* "The 
faunas of the Chester, St. Louis and n\os\.[ not all] of those 
referred to the Warsaw formations are paleontologically more 
closely allied than they are to the faunas of the Keokuk and 
Burlington." It is thus seen that he carefully excludes a part 
of the Warsaw faunas, and clearly implies their relationship 
with the Osage faunas. That Mr. Keyes and Prof. Williams 
are in accord in this regard is shown by the following state- 
ment by Mr. Keyes :f "In a majority of cases the so-called 
*U. S. Geol. Surv., Bull. 80, p. 169, 1891. 
tGeoL Surv. Iowa, vol. I., p, 70, 1893. 
