THE ANTIQUITY OF MAN IN NORTH AMERICA. 333 



peiidiciilar, as would be the case if it had fallen down some root- 

 hole, animal's or insect's burrow, or opening in the earth from any 

 cause, and now obliterated. 



Fig. 3. — OccuKHEXcE of an Ai:gillite 1mplkme>'X in Gl.vi'ial Stratified Sand. 



