RELICS OF MAN IN THE GLACIAL PERIOD. 247 



disappear, and implements of palaeolithic type only are 

 found. 



Fig. 67. — Face view of argillite implement, found by Dr. C. 0. Abbott, in 1876. 

 at Trenton, New Jersey, in gravel, three feet from face of bluff, and twenty- 

 two feet from the surface (No. 10,985) (Putnam). 



In the year 1882, after I had traced the glacial bound- 

 ary westward from the Delaware Eiver, across the States 

 of Pennsylvania, Ohio, and Indiana, I was struck with 



