Classification of tJie Mississippiaii Scries. — Keycs. 1 1 1 
gruity between an hypothesis of geological correlation and 
classification and the practical scheme as actually developed 
in the field. Has it not been this very lack of effort to draw 
close lines that has enabled the paleontologist to fancifully ex- 
tend the geological formations around the world, like the con- 
centric layers of an onion? Is it not this very discordance be- 
tween the theoretical fossil scheme and the actual succession 
of beds as determined by exact methods that has led every 
working geologist in this country to abandon the fossils as 
the all-important criterion, and to use in their place for the 
stages and series the lithological and other characters? Until 
this theoretical fetish was set aside stratigraphy and historical 
geology, as usually limited, had not made a single step forward 
for 50 years. 
The subdivisions of the Mississippian series form one of 
the best examples that could possibly be selected to illustrate 
the point. Mr. Weller says that the arrangement proposed 
"by Williams is a natural faunal classification, while the second 
by Keyes is a stratigraphic classification." Just what an un- 
natural faunal one is we are left to conjecture. The subdivi- 
sions of Chouteau, Osage and Ste. Genevieve remain to this 
day wholly undefined, except in terms of the stratigraphy. 
There exists not even the slightest trace of a criterion by 
which to distinguish a Chouteau from a Ste. Genevieve fauna, 
or an Osage fauna from an Osage Indian. Yet, says Air. Wel- 
ler, "the commonly recognized local geological formations 
were placed as accurately as was possible at that time, in their 
respective epochs, and further investigation seems to necessi- 
tate no different disposition of them." Of course not! How 
could they be differently disposed in a scheme having no defi- 
nition and hence no existence. 
Only two persons exist who understand what makes up 
each of the three faunas of the Mississippian series. One is the 
author of the names himself and the other is his defender. If,- 
however, judging from the defense, the Chouteau or Kinder- 
hood fauna is a "natural faunal unit," if the Ste. Genevieve 
fauna is a natural and homogenous group" it is to be hoped 
that in our final faunal classification of geological time and 
substance, we shall have only unnatural faunal groups to work 
upon. 
