Serial N^omenclafiire of the Carhoniferous. — Kei/es. 25 
It is proposed therefore to recognize in the "upper" Car- 
boniferous of the Western Interior province three series hav- 
ing equal taxonouiic rank. The entire Carboniferous of tlie 
region would be arranged as follows : 
I Oklahonmn. 
r, J Missouriau. 
Carboniferous.-^ ^^ ,^ . 
I Des Moines. 
1 Mississippian. 
The Mississippian series is the basal portion of the Carbon- 
iferous. It is almost entirely composed of limestones and the 
more open sea depositions, which contrast sharply with the 
shore deposits superimposed upon them. A marked line of 
unconformity separates the two classes of deposits. From 
this line it includes all beds below to the Devonian. To this 
basal series of the C-arboniferous the term "Subcarboniferous" 
was widely applied until recently, when the title "Lower Car- 
boniferous" was substituted. The history of these names and 
their various applications has been so fully reviewed lately* 
that there is little to add. The title Mississippianf is a revi- 
val, with a slight terminal modification, of a name originally 
suggested by Alexander Winchell.;J; 
As a definite geological terra the name Des Moines was pro- 
posedg for the principal coal-bearing strata of Iowa and 
Missouri, embracing essentially what had been previously 
called the " lower " and " middle " Coal Measures. The name 
was given because the Des Moines river flowed, for a distance 
of more than 200 miles, directly through the area occupied by 
the beds of this age. Moreover, Owen || had early applied the 
term of Des Moines coal field to the region, though without 
modern geological significance. The formation was defined 
as extending in a broad belt from north-central Iowa south- 
ward into Missouri, following around the northern and wes- 
tern flanks of the Ozark uplift into Kansas and Indian Terri- 
tory. The designation "was designed to apply to one of the 
main divisions of the Carboniferous, as is manifestly shown 
in dividing into two principal parts all the Coal Measures of 
*MiP8()uri Geol. Sur.. vol. iv. i)|). 4.3-4i, 1894. 
tWilliams: Bull. U. S. (Icol. Sur., no. 80. p. 13."), 1891. 
JProc. Am. Philos. Soc, vol. x], p. 77, 1879. 
tjMon. Rev. Iowa Weather Service, vol. iv, p. .3, 1893: and Iowa Geol. 
Siir., vol. I, p. 85, 1893. 
llProc. American As. Ad. Sci., vol. v, pp. 47 50, 1851. 
