Plate 20 



i . : i Fmiiil ii 



From a photograph of a sample stone taken from about a meter 

 below the surface of the material now on the floor . of Bat cave. 

 It shows conclusively that no one of these blocks is moved over 

 the surface of another and that the cave is therefore not eroded 

 through any shifting of this material. Specimen in possession of 

 New York State Museum 



