THE ILLINOIAN ICE INVASION" 313 



b. Fhmatile Deposits 



An interesting deposit occurs at Cincinnati, Hamilton County, which con- 

 tains a small fauna. A section, made 20 years ago, is indicated below : u * 



Yellow clay 5 feet 8 inches 



Blue clay 7 " 3 " 



Height of section 13 feet 1 inch 



The contact portions between the two clays contained fragments of wood 

 and vegetation in one place, which probably represented the Sangamon soil 

 horizon. The blue clay contained sand pockets containing the following spe- 

 cies of shells : 



Physa ancillaria Planorbis parvus 



Anculosa costata (of small size) 



Equus fraternus and Mammut americamim were also secured from the blue 

 clay. The yellow clay is probably loess. 



Many years ago, Hildreth 143 described a well boring which passed thru 

 strata evidently referable to the Sangamon interval; the lower strata may, 

 however, be of older date. As the region is far outside of the till margin, the 

 age of the deposits cannot be placed with certainty. Valley drift from the 

 Illinoian and Wisconsin drift sheets extends down the Muskingham River 

 to the Ohio. The well was located six miles above the mouth of the Musking- 

 ham River and one and one-half miles north of the Ohio River. The section 

 included the following strata (correlation the writers) : 



1. Ash colored clay (probably loess) 40 feet 



2. Blue clay with fragments of plants, leaves, and seeds of monocotyledenous plants; 

 beneath this a bed of wood, leaves and plant remains (Sangamon old soil?) 10 " 



3. Fine siliceous and micaceous sand, the upper part mixed with blue clay such as is 

 now found in the bottom of fresh water ponds or in eddies and lagoons of large 

 rivers. Scattered throughout the 10 feet, and especially in the upper portion, are 

 numerous fluviatile shells apparently Unio and Anodonta. (Sangamon or possi- 

 bly Yarmouth) 10 " 



Depth of well 60 feet 



The Unios are given names by Morton and are also figured, but the cuts are 

 not good enough for identification with recent species. These names, which 

 are not recorded in Simpson's Synopsis, are listed below: 



Unio petrosus Morton. Plate 1 figure 17. Page 149 

 tumulatus " " 1 " 18-21. " 149 



142 Hayes, Journ. Cin. Soc. Xat. Hist., XVII, pp. 217-226. 

 14J Amer. Journ. Sci., (i), XXIX, pp. 17, 149, plate 1, 1836. 



