IH NKW YORK STATK MTSKF-M 



more fiViUKiulv Iruin ilic Lowvill(» liiucstono; and prevailiuglj 

 from oxtroniely fossil iferous black and liiav limostone bcKls which 

 are of lower or lowest Trenton age. 



5 A specially interesting fcatnre of the fanna of these Trenton 

 IK*l>hlc8 was found in \W considerable number of new forms, 

 largely bnichipods, trilobites and ostracodes. Some of these 

 belong to genera new to the American Trenton but well repre- 

 sented by very similar forms in equivalent north European 

 b(Hls. These, as well ais several other forms which also occur 

 in the Kysi'dorph hill conglomerate and are restricted to the 

 eastern Trenton, support the conclusic.n derived from the distri 

 bution of the Normans kill graptolite shales, viz that in lower 

 Trenton time the eastern Trenton sen lind ntfninod connection 

 with the Atlantic. 



C> As the fauna of the Trenton jK^bbles is in marked features 

 different from that of the beds kno^^^l in the Mohawk and Hud- 

 .^o-n valleys, it is supposed that the material was derived from 

 the regions to the east and northeast, where the Trenton beds 

 have now become metamorphosed and the fossils obliterated. 



7 The occurrence of the lower Trenton limestone {lebbles in 

 this region is taken to indicate that at the beginning of the Tren- 

 ton period the quiet limestone-depositing Trenton sea extendi^l 

 also over this region; while the pi-esence of the Nonnans kill shale 

 of lower Trenton age proves that this favorable condition soon 

 came to an end, and a radical change in the physical conditions 

 took place. 



8 The conglomerate itself is intraformational. It is embedded 

 in shale of the same age, and the fauna of the matrix of the 

 conglomerate is of lower Trent «»ii ;igr. The conglomerate, there- 

 fore, evidently d^ies not maik ;iii,\ imjw)rtaiil change' in Ihe physi 

 cal conditions of the region, but is probably due to a temi>orary ele-- 

 vation of a h»w A]q>alachian ridge into the sphere of wave action. 



