1846.] The JVew York System. 201 



excludes of course the Devonian of Phillips. We have little 

 doubt but this last system can be made out here, as we have dis- 

 covered some of its forms in addition to those which belong to 

 the upper Silurian of Murchison; still it appears to us that geolo- 

 gy is simplified by extending the New York system as proposed. 

 It is proper to observe that Mr. Vanuxem's views led him to pro- 

 pose this extension in his report. We have however made these 

 remarks from conviction of its utility by our own observations. 

 By adopting this division we secure strong and palpable lines of 

 demarcation, and it will free us from jarring opinions where the 

 Devonian shall begin. There is more difficulty in fixing upon 

 the dividing lines of two adjacent systems, than may appear at 

 first sight. In the case of the Devonian, some propose to bring 

 it down to the corniferous, an extension which decapitates the 

 Silurian. Another proposes the Oriskany sandstone as its base, 

 or the rock upon which it shall be based. The reason for this 

 extension is, that Devonian fossils are found in these rocks. But 

 this is reckoning or levelling only one way. It would not be diffi- 

 cult to show that the Silurian fossils go up nearly to the top of the 

 Devonian series, and so often, that the whole base as proposed by 

 Phillips, if the matter was to be decided in this way, would be 

 thoroughly excised. The facts, then, as they stand now, present 

 obstacles to the satisfactory adjustment of dividing lines between 

 the two systems, and as fossils fail in establishing the line, we shall 

 be obliged to do one of two things, adopt arbitrarily one system and 

 exclude the other, or else do as has been done in other cases of 

 greater importance when lines were wanted ; appoint commissioners 

 to run an equitable boundary, paying due regard to the prior claims 

 of each system as they are established by anterior published and 

 printed documents. In England however, if priority of publica- 

 tion should be made the basis of adjustment, the Cambrian sys- 

 tem would come in for a large share of the lower Silurian rocks. 

 We have little doubt but that the series containino; the Bala lime- 

 stone, which is equivalent to our Trenton, belongs legitimately 

 to the Cambrian. 



We have in another place shown, as we think, that one of the 



