lO Natural History Bulletin. 



the correctness of the position in the geological series that 

 later and more careful study has assigned to these sandstones. 



Up to the present time no one so far as I know has called 

 in question the propriety of assigning the yellow sandstones 

 above the mouth of Pine Creek in Muscatine county to the 

 same horizon as the yellow sandstones at Burlington. Hall's 

 statement as to their equivalency has been accepted as finals 

 and when the sandstones of Burlington were transferred from 

 the Chemung period to the Sub-carboniferous, by common 

 consent the spirifer-bearing sandstones of Muscatine count}"" 

 were supposed to be similarly transferred. White speaks of 

 the Kinderhook beds as striking the Mississippi River at 

 Muscatine,! S. A. Miller refers Spirifcra capax,^ Hall to the 

 Kinderhook Group. Hall in a recent publications speaks of 

 S. capax as from the " Lower Carboniferous, mouth of Pine 

 Creek, Iowa." Calvin influenced by the general concurrence 

 of opinion states that "the Kinderhook is seen resting on the 

 Hamilton in Muscatine county."* Other writers, similarl}- 

 influenced have been led to support the view that the sand- 

 stones at Burlington and the sandstones near the month of 

 Pine Creek belong essentially to the same geological horizon. 



During the past ten years the writer has made repeated 

 excursions to the region near the mouth of Pine Creek, 

 attracted first by unusual facilities offered for collecting beauti- 

 fully preserved casts of the so-called Spirifera capax, and 

 afterward by the desire to study anew the stratigraphical 

 phenomena of the region. A very casual study of the facts 

 now available in determining the geological problems of the 

 region in question, is sufficient to demonstrate that the spirifer- 

 bearing sandstone at Pme Creek is not the stratigraphical 

 equivalent of the Kinderhook sandstone at BurHngton. The 



1 White's Geology of Iowa, 1870, Vol. I., p. 1S9. 



2 American Palseozoic Fossils, S. A. Miller, 1SS7, p. 129. 



3 Report of State Geologist for the year 1S82, Albany, N. Y., Plate 52, 

 Figs. 15, 16, and description of plate. 



4 Notes on the Geological Formations of Iowa, p. 7. Prepared for distribu- 

 tion at the World's Industrial Exposition at New Orleans, 1SS5. 



