586 H. F. BAIN AND A. -G. LEONARD 
beds throughout the state but varies in detail so much that it 
is impossible to correlate the individual beds of the north, 
middle and south sections. The uppermost beds represent a 
necurrence sol the sty pe sof sedimentation shown by the lower 
member and present a notable thickening to the south. Indeed 
this member is practically absent at the northern end of the 
area so that the Iowan field includes apparently only the north- 
ern half of an immense lense of sandy material, intercalated 
between the limestones of the Bethany and the Appanoose 
formations. 
As has been pointed out. by Keyes* there is a close corres- 
pondence between the sections made out in Iowa, Missouri, and 
Kansas. These may be summarized as below. 
lowa Missouri Kansas 
By No name Pleasanton Pleasanton 
g Pawn 
2h | Appanoose Henrietta te 
Oswego 
| 
il | Cherokee Cherokee Cherokee 
The Middle Coal Measures as originally defined included 
the two upper divisions noted here. Swallow’ recognized along 
the Missouri and at the top of his section some thirty feet of 
sandy shales. White and St. John found about the same thick- 
ness along the Raccoon River. Between these two points it is 
now known that the sandy member attains a considerable thick- 
ness and becomes sufficiently distinct to perhaps warrant giving 
it a separate designation. For this division Haworth’s term 
Pleasanton seems to have precedence if the beds are to be con- 
sidered as distinct from the next lower formation. 
The middle member of the above table includes the major 
1 Proc. Iowa Acad. Sci., Vol. IV, pp. 22-25, 1897. 
2Op. cit., pp. 82-83. 3 Kan. Univ. Quart., Vol. II, p. 274, 1895. 
