The Upper Neocene 

 deposit of Bacillaria around Boston, Massachusetts 



by ARTHUR M. EDWARDS, M. D. 



When I received the deposits of Bacillaria around Boston, Mas- 

 sachusetts in 1893 I was disposed to place them in the Raised Coast 

 period, but as I studied them I fìnd that the coast is going down now 

 and has properly been twice at least raised before. This made me 

 think that it does not belong to the Raised Coast period. I named 

 it the Raised Coast period from an epoc which was evidently Re- 

 cent. Dr. J. S. Newberry called it the Littoral Plain but he did no 

 place it in a period. He evidently thought that it was Recent. But 

 at that time it had not been properly studied and an opening into 

 it had not been made. Now that they have made one when sinking 

 the tunnels through which the rail road will shortly run a new 

 aspect of the clay is revealed. I have studied il for several years 

 and have obtained some valuable points in the geology of the Hud- 

 son Ri ver. 



First I will describe what the specimens are and them why di- 

 splace them in a period which is different from placing them in 

 the « mud » of the marches. They are clayey, that is to say they 

 contain a certain amount of aluminium silicate, clay though not enough 

 to classify them as clay. 



They are the Esse* marches, Essex, Massachusetts as they are 

 labeled by the Revd. Tempie Cutler. Essex is on the north side of 

 Cape Ann, twenty - six miles from Boston. Cape Ann is the most 

 northern end, Cape Cod is the southern Cape of Massachusetts, Bo- 



