was made in direct contact with the Kansan drift and the bottom 

 collection in contact with the mineral soil of Nebraskan age. 



The methods employed in preparing the peat for examination 

 are as follows : The dried peat was broken down by crumbling 

 and boiling it in water until dispersed. Then several cubic centi- 

 meters of 10 percent ammonium hydroxide was added and the 

 liquid was thoroughly stirred. This was passed through a one 

 millimeter mesh screen and the liquid was allowed to settle. After 

 decanting, the liquid was again stirred and temporary microscopic 

 mounts made. These were studied under a microscope using a 15X 

 ocular and a 3 millimeter objective. The slides were controlled 

 and systematically examined with a mechanical stage. 



Plant microfossils were fairly abundant and one hundred and 

 fifty from each level were counted and percentages computed for 

 the various species. In Table 1 are listed the percentages. These 



Table 1. Percentages of microfossils in a Pre-Kansan peat deposit near Belle 



Plaine, Iowa 



Depth in Inches from Upper Contact 

 6 4 2 



Species Percents 



Sphagnum 0.0 5.3 59.5 0.0 



Piniis Strobus and P. resinosa 9.0 20.0 8.9 9.3 



P. Banksiana 0.0 0.0 0.0 1.3 



Picea glauca 31.8 12.3 4.6 44.0 



P. mariana 18.5 0.0 3.0 18.0 



Abies balsamea 4.5 6.1 0.0 10.6 



Gramineae 22.7^ 24.6 .7 2.6 



Cyperaceae ., O.o' 10.0 5.3 2.6 



Betula sp 4.5 .7 4.1 6.6 



Quercus sp 4.5 11.4 2.0 2.6 



Acer sp 0.0 0.0 5.3 0.0 



Tilia sp 0.0 0.0 1.3 0.0 



Compositae 4.5 9.6 5.3 2.6 



are computed from all of the recognized fossils that occurred in 

 the samples. Figure 1 shows graphically the percentages of tree- 

 pollens. These were computed exclusive of the moss spores and 

 herbaceous pollens. An examination of the species recorded in 

 Table 1 indicates that like the fossil floral assemblage in Minne- 

 sota, it is one of considerable complexity. If one compares the 

 two assemblages, they are found to be strikingly similar. The 



