24 
IOWA ACADEMY OF SCIENCES. 
whose meaning can be easily defined. More recently another 
title has been given to practically the same formation, but as 
the two are essentially coterminous it seems that the earlier of 
the two can be retained with advantage. The latter term 
includes only a few layers additional, which are also well 
exposed at the typical locality. The latter term is Oswego, 
which, thouirh used previously without definition, was described 
only very recently.* 
The medial shale member may be designated as the Marmaton 
formation from the stream of the same name in Vernon county, 
Missouri, and Bourbon county, Kansas, where the shale may 
be considered as typically developed. 
The Pawnee limestone forms the upper member of the Hen- 
rietta. The term was first used by Swallow f for a heavily 
bedded limestone occurring in southeastern Kansas. 
Pleasanton Shales . — The name Pleasanton was first applied by 
Haworth. J; There is, however, some difficulty in determining 
just what title is the proper one to use in this connection. 
Swallow § seems to have had essentially the same idea in apply- 
ing to the principal coal-bearing shales immediately overlying 
the Pawnee limestones in southeastern Kansas, the term 
“Marais des Cygnes coal series.” He, however, appears to 
have gotten the upper part considerbly mixed, especially the 
limestones, if later work is to be relied upon. Only the lower 
half of this coal series can be regarded as forming the equiva- 
lent of the Pleasanton, or numbers 194 to 202 of Swallow’s 
section. These beds are typically exposed in Bourbon county, 
and along the Marais des Cygnes river in Linn county, Kansas, 
the locality being practically the same as that in which the 
town of Pleasanton is situated, so that the original localities 
for both are essentially the same. The “series,” however, 
evidently embraces so much more than it should to form a com- 
pact, easily defined formation, and the upper part, moreover, is 
so far from being correct that it would seem best not to attempt 
to restrict and redefine the limits of the formation in order to 
retain the name. 
For the strata lying between the Pawnee and Bethany lime- 
stones Haworth and Kirk|| first suggested the name Laneville 
*Univ. Geol. Sur., Kansas, vol. I, p. 151, 1896. 
tKansas Geol. Sur., Prelim. Rep., p. 24, 1866. 
^Kansas Univ. Quart., vol. Ill, p. 274, 1895. 
§Kansas Geol. Sur., Prelim. Rep., pp. 22-24, 1866. 
!l Kansas Univ. Quart., vol. II, p. 108, 1894. 
