Rhodora Plate 91. 
13. Copy OF A PORTION or DE GEER’S MaP OF 7HE LAST 
CHANGE OF LeveL IN EasterN Nortu America. BROKEN 
LINES ARE ISOBASES WITH 200 FOOT INTERVAL. DOTTED 
PORTION, THE SUBMERGED COASTAL PLAIN, A. SUBMARINE 
RIVER-CHANNELS. 
