ORGANIC REMAINS OF THE TACONIC SYSTEM. 



• 



De. Emmons, in his paper on the Taconic System, and in his Agrictfltural Report, has 

 given several plates of fossils of the Taconic system, with descriptions of the same. The 

 larger nmnber of these are from the State of Maine ; and since the relative position of the 

 rocks containing them has not been shown upon geological evidence, nor any fossils from 

 them identified with those of rocks of the [presumed] same age in New-York, I have thought 

 it better to omit any notice of them in this volume. Of those found within the State of 

 New-York, several are unequivocally identical with well known species in the Hudson- 

 river group, while a single species is yet unknown in that position. 



The Trilohites are figured on Plate LXVII, and described at pages 252 and 256 of this 

 Report. One of these is new, while the other is unquestionably the Calymene beckii. 



The J^Temapodia has since been shown, by Dr. Fitch, to be the track or discoloration on 

 the surface, produced by some existing animal. 



The Gordia marina presents no evidence of organic structure, having more the ap- 

 pearance of the cast of a furrow made by some moUusk upon a soft bottom, which was 

 afterwards filled with sediment, producing the form under consideration. 



The JVereites and Myrianites, figured on Plates III and IV, Tac. System {Plates XV and 

 XVI, ~9gr. Report ) , are, as before observed, from the slates of Waterville in Maine, the 

 age and relative position of which has not been shown upon other evidence. 



The Fucoides simplex is undoubtedly a Graptolite, allied to G.foliaceus, and apparently 

 identical with a species in the unaltered slates of the Hudson-river group. 



'£\iG Fucoides rigida and F.Jlexuosa are one and the same species; but their locality 

 leaves no doubt that the rocks in which they occur are a part of the Hudson-river group. 

 A species, undistinguishablc from this one, occurs in the unaltered shales of the Hudson- 

 river group at Turin in Lewis county, though such variable forms are not to be regarded 

 as of cardinal importance. Even if this prove a distinct species, it is generically identical 

 with others from authentic localities of the Hudson-river group, and is therefore of little 

 value as typifying rocks of a distinct system. Such an argument, however, if available in 

 this case, may be used in another ; for the two species of Sphenothallus {V\. LXVIII) are not 

 associated with otlier known fossils, but are clearly in strata of the Utica slate and Hudson- 

 river group. The only difference in the case of those in Washington county, is that the 

 rocks have suffered a few undulations and plications, with scarcely any visible change in 

 their lithological character. 



