276 Remarks on the TaGoniG System. 



XXIY. — Remarlis on the Taconic System, 



By R. p. Stevens. 

 Eead May 21, 1860. 



The existence of a system of stratified rocks, older than the 

 Potsdam sandstone, and fossiliferous, has been the mooted ques- 

 tion of the day. 



Mather, the brothers Eodgers, Hall, Sir William Logan, 

 Hunt,, and recently Pres. Hitchcock must be added to the list, 

 maintain that there is no such system. That the Potsdam and 

 calciferous sandstone are the lowest horizon of Palaeozoic life ; 

 and that the slates, sandstones, and marbles, of Prof. Emmons' 

 Taconic sj'stem, are but the metamorphosed rocks of the lower 

 Silurian. 



On the contrary side of the question we have Prof. Emmons, 

 the proposer of the system, Safford, Jewett, Foster, in our 

 country, and Barraude and Salter, in Europe, who maintain not 

 only that this system of rocks is older than the Silurian, but 

 that it was the cradle of palseozoic life. 



Mr. Sterry Hunt, the accomplished chemist of the Canadian 

 survey, carries the idea of metamorphism so far as to make 

 the limestone of Central Massachusetts, the Devonian, altered 

 by heat and chemical agency. Doctor Hitchcock lends his 

 authority to the same view. Such is the present aspect of the 

 controversy. 



The fossils before the Lyceum this evening are from the 

 Taconic and the Silurian, where it reposes upon the slates un- 

 conformably. The Silurian fossils are the Madura magna^ two 

 specimens, Gyrstoceras, and Orthoceras, one of each, with frag- 

 ments of others. The Taconic fossils are, Paradoxides^ one 

 specimen, Grajptolithes seculinus, one specimen, and Fucoides 

 Jlexuosa. 



It was my intention to have laid before the Lyceum speci- 

 mens of Brachiopods, new Trilobites, and stems of Encrinites, 

 but my communications did not reach Albany in time. 



