50 THE NAUTILUS. 



FOSSIL LAND SHELLS OF THE OLD FOREST BED OF THE OHIO RIVER. 



BY A. C. BILLUPS, LAAVRENCEBUKG, IND. 



During the spring of 1902, owing to tlie unusually heavy rains 

 which caused much cutting to be done on the banks of the Ohio and 

 Great Miami rivers, near Lawrenceburg, Indiana, I had a fine 

 opportunity to examine this interesting formation, the Old Forest 

 bed, from a conchological point of view. 



I had many years previously found large numbers of broken and 

 bleached shells of species which are foreign to this locality in drift 

 piles of the Great Miami and Ohio rivers, which I had always put 

 down as dead specimens which had floated from some point far 

 above where they were found. 1 found that this conclusion was 

 erroneous and that these shells were washed from the deposit which 

 contained them, and floated to the various drift piles where they first 

 attracted my attention. 



The Old Forest bed is a stratum of several feet in depth, six to 

 eight feet below the present surface of the bottom lands of the Ohio, 

 and contains in many places the well-preserved remains of mammoth 

 trees ; these are covered with a thick layer of yellow clay of an 

 exceedingly hard and solid texture, which renders very difficult the 

 extraction of fossils so delicate in structure as the land shells. 

 About the only satisfactory way to obtain good specimens is to wash 

 out with water until the clay is softened and then, if good luck 

 follows you, you may obtain a respectable specimen. The use of a 

 knife or chisel is absolutely useless, as in nearly every case the fossil 

 extracted by these means is cracked or broken. 



The comparison between these fossil forms and the species now 

 found in this section is extremely interesting and worthy of study. 

 To give a general idea of the species and to illustrate the difference 

 between the fossil and recent faunas, I give the following list with 

 notes on each species, which will show clearly what time has done 

 to modify the molluscan fauna to the changed conditions of the 

 present time. 



It is remarkable how well the red coloring matter of all species is 

 preserved, particulariy in the case of P. alternata Say. 



VdJIonia pvldiella Mull. Traces only of this minute shell. 



Poly gyro triderttata Say. Not many found, and these much more 

 elevated and more deeply striated than the local living specimens. 



