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NEW YORK STATE MUSEUM 



Professor Hall in the above gave special attention to the remarkable 

 casts of ridges and striae, and the specimen of these which he chose 

 for his illustration is of such fine quality that the figure is here 

 reproduced. It is no wonder that he compared them to glacial 

 scratches upon subsoil rock surfaces, and little wonder, either, that 

 later observers have looked somewhat suspiciously upon these scored 



and grooved slabs as remarkably suggestive of ice work. In a para- 

 graph directly following that quoted. Hall mentioned the fact that 

 in two instances he had noted the direction of these ridges and 

 found that it was nearly east and west. He also calls attention to 

 the fact, which one occasionally sees, of the ragged surface of the 

 furrow which was due, he intimates, to a tremulous motion in the 

 body making it ; just as one finds not infrequently among the glacial 

 grooves. Furthermore, Professor Hall distinctly states his belief 



