ft 
122 The American Geologist. February, 1902, 
sense, the term Chouteau ranks taxonomically with the titles Osage 
and Genevieve. As the term was clearly defined as a part of the 
formation subsequently called Kinderhook, it is certainly impos- 
sible to drop its meaning in this sense. By no canon of nomen- 
clature can the term in the second sense be retained. So the quicker 
it is eliminated in the last mentioned application, the less is the 
confusion that is likely to ensue. ‘Chouteau, if it is to be retained 
at all, as a valid biotic term in geology, can only be made to apply 
to the fauna of the stage of the Chouteau limestone and its equiv- 
alents. In this sense it satisfies all the requirements of dual classi- 
fication in geology. Moreover, it may refer to a fauna that is a 
compact unit. It applies to a fauna that is believed to belong en- 
tirely to the Carboniferous. It eliminates the elements which are 
not Carboniferous in character. 
Although the title “Chouteau fauna” frequently appears in re- 
cent geological literature, it is rarely used with precise mean- 
ing. The biological geologists are inclined to apply the term to the 
oldest of the three faunal categories into which they subdivide the 
“Eocarboniferous” of the Mississippi valley. But the “Kinderhook” 
formation is now known to contain a mixture of faunas, or rather 
several distinct faunas. 
There is another grave consideration which is seldom taken into 
account. The fauna which is generally thought to be the fauna from 
the original Chouteau limestone is at best a fancied medley of shad- 
dowy definition. Practically no detailed work has yet been done on 
the fossils of this formation. Careful determination of the exact 
horizons of the various forms has not even been attempted. Of the 
species described as from the original Chouteau in central Missouri, 
many are now known to be from formations other than the terrane 
under consideration. It is small wonder, therefore, that the Chou- 
teau or Kinderhook fauna as we have long known it, is apparently 
ill-defined, anomalous, and puzzling. In the critical study of the 
lowest Carboniferous faunas of the Mississippi valley there is need 
before all else of exact determinations of the various organic forms 
that actually occur in Chouteau limestone at the type locality in cen- 
tral Missouri. It is only with this type-fauna that the faunas of the 
Kinderhook from other localities and other horizons can be com- 
pared with profit. Until the fossils from the original Chouteau are 
carefully collected and studied anew and in their enirety the “Chouteau 
Fauna” must be regarded as a quantity unknown. 
It is manifest that one of the very first “Kinderhook faunal studies” 
should be a study, at first hand, of the fauna of the original Chouteau 
limestone. 
A noteworthy point, in the third enstallment, is the consideration 
of the first layer underneath the beds in question—the Chonopectus 
sandstone—as pre-Louisianan; that is, older than any part of the ori- 
ginal Kinderhook. If this be the true interpretation, the Carbonifer- 
ous must be cut off at the bottom at a very much higher level in the 
