Review of the New York Geological Reports. 151 



and shales in the southern part of the State, known as the Che- 

 mung group ; and considers them both as belonging to the Old 

 Red or Devonian system. And. in truth, it is matter of doubt 

 which is the correct hypothesis ; as we shall see when we come, 

 by and by, to sum up the evidence derived from organic contents, 

 lithological character and superposition. 



No region ever yet explored, presents these protozoic strata, as 

 the New York geologists aver, in so extensive, undisturbed de- 

 velopment, as their State ; and no country seems to afford such 

 fine natural sections suited for the study and classification of 

 rocks of this age. It is for this reason, that the New York geol- 

 ogists, following Dr. Emmons' recommendation, have adopted the 

 term " New York system." If a local nomenclature be admis- 

 sible, no country can be better entitled to transfer its name to a 

 geological system. We object, however, to locaj. terms, except 

 as provisional, because they are not generally applicable, and be- 

 cause they multiply synonymes, and render the geological vocab- 

 ulary unnecessarily complicated. 



No system of nomenclature is, in our view truly worthy of 

 adoption, but one that is universally applicable to every region 

 of the earth ; pointing directly to the place in the chronological 

 scale, which the formation designated occupies. 



The total thickness of the New York system is between seven 

 and eight thousand feet. According to Dr. Emmons' classifica- 

 tion, the system in question consists of four principal divisions, 

 named from the districts where they are in greatest force and 

 best characterized. In the ascending order, they are as follows: 

 Champ lain division, Ontario division, Helderberg division, and 

 Erie division. 



The area which each of these occupies in New York is as 

 follows : 



The first division encircles the primary ; and its upper strata 

 extend from the union of the Hudson and Sacandago rivers, south 

 down the valley of the Hudson, occupying the country between 

 the eastern State line and the Helderberg range of mountains. 

 The whole region comprising this division in New York forms a 

 figure resembling the written letter g. 



The Ontario division ranges along a belt of country running 

 east and west, parallel with the southern shore of the lake of 

 that name, nearly of uniform width, being the distance between 



