C. D. Walaott — The Taconic System of Emmons. 237 



rane is so much more extensively developed farther west, in 

 the section, that I will omit its description until passing down 

 the western side of the synclinal formed by terrane number 

 three. (See Section on the map.) 



Terrane No. 3. — This is the limestone and marble belt that 

 outcrops both on the eastern and western side of the Taconic 

 range. Its distribution is shown on the map and in the sec- 

 tion, and I think it unnecessary to restate the evidence given 

 by Professor Dana to prove that this limestone belt is the rep- 

 resentative of the limestones of the Trenton-Chazy-Calciferous 

 series of the western side of the Champlain basin. His con- 

 clusions are based on the stratigraphy, supported by paleonto- 

 logic evidence,* discovered by Messrs. Wing, Dana and 

 D wight on the western side of the Taconic range, north and 

 south of the typical area. The fossils have been referred, 

 however, to the sparry limestone or " Upper Taconic" by 

 those writers who favor the view of the pre-Cambrian age of 

 the "Lower Taconic." Prior to August 5th, 1887, determin- 

 able fossils had not been found in the limestone series east of 

 the Taconic range. At that date, I found, in the eastern lime- 

 stone, in the town of Pownal, Vt., about half a mile north of 

 the Massachusetts line, a number of fossils that were weathered 



out in relief on the surface 

 of a compact, clouded mar- 

 ble. The collection gives 

 Euomphalus ? (tig. 1) ; the 

 lower whorl and aperture 

 of a shell like Murchisonia 

 hellieineta (tig. 2); two 

 whorls of a form identical 

 or closely allied to Murchi- 

 sonia Milleri (fig. 3). (tig. 

 4 is a cast of Murchisonia 

 Milleri, from the Cincin- 

 nati formation, for compar- 

 ison with fig. 3) : a cross- 

 section and lower whorl of 

 a Paphistouia-like t shell, 

 and a large, crushed gaste- 

 ropod shell. The fauna 

 belongs to the Trenton 

 terrane, and, by it, we can correlate the Eastern with the 

 Western limestone. | 



In September, 1887, I found fossils in the limestone on both 



* See Professor Dana's papers iu Am. Jour. Sci., 1872 to 1887. 



f Paper read before the American. Association for the Advancement of Science, 

 August, 15th, 1887: "Discovery of Fossils iu the Lower Taconic of Emmons." — 

 C. D. W. 



