22 The America II (ieologist. July, 1S96 
SERIAL NOMENCLATURE OF THE 
CARBONIFEROUS. 
By Charles R. Keyes, Jefferson City, Mo. 
When the problem of subdividing the C'arboniferous of the 
upper Mississippi valley came up for consideration, a few 
years ago, it was found that the limits ascribed to the com- 
monly recognized divisions were not only unnatural ones but 
that they were not the same in different states or even in all 
parts of the same state. It was seen, however, that with some 
modification of the existing arrangements, in Iowa and Mis- 
souri particularly, all the strata of the upper Carboniferous 
could be grouped into two series corresponding in a general 
way to the "lower" and "upper" Coal Measiires. It was 
then projjosed to abandon the old names and to otter in their 
stead the geographic titles of Des Moines and Missouri.* 
Since the two terms mentioned were first introduced into 
geological literature they have been extended to other parts 
of the region. In several cases, however, there appears to be 
some misconception regarding the original usage of the terms 
and their exact taxonomic rank. Tiiis misunderstanding of 
the real extent of the terms is particularly noticeable in two 
recently published articles, one on the lower portion of the 
Kansas Coal Measuresf and the other on the upper part of 
the Carboniferous of the same state.;]; The accompanying 
note, however, is not intended as a criticism on the excellent 
work lately done in Kansas. It is rather a statement made at 
this time to correct certain erroneous expressions which do 
not appear to be confined entirely to those papers already 
published, and to point out more clearly than has been done 
the exact vertical extent of the formations and the relations 
of the Kansas divisions to those of the neighboring states. 
It is well known that, on account of the great industrial 
value of the mineral deposits contained, the Coal Measures of 
the Mississippi valley were the first to receive special geologi- 
cal attention. Yet notwithstanding this fact it has only been 
of late years that satisfactory information has been obtained 
upon which to base a subdivision tliatis applicable to the en- 
tire Western Interior province. The local classifications, if 
*Iowa Geol. Sur., vol. i, p. 85, 1893. 
tKansas Univ. Quart., vol. iii, pp. 271 '278, 1895. 
^.Journal of Geology, vol. iii, p. 800, 1895. 
