the distribution of the Portage and Chemung groups of southern 

 New York. Into the Embayment of the sea flowed large rivers, 

 and brought the sand, mud and slime among which lived the 

 shells hereinafter figured. It is this vast accumulation of sedi- 

 mentation that has subsequently been raised above sea-level and 

 still later carved by flowing waters that makes the beautifully di- 

 versified region of southern New York. 



The Portage material was deposited first, hence underlies, 

 passes under, the Chemung. Beneath the Portage in turn are 

 Middle Devonian, Hamilton beds, cropping out across the state 

 north of the Portage. They passed through similar stages 

 of formation to those of the Upper Devonian beds, though in a 

 somewhat more remote period of time. 



Ij|j ! ,|| Area when Portage rocks are near the surface. 

 Just beneath soil. 



Area where Chemung rocks are near the surface, 

 just beneath soil. 



Fi Z- 4- 



