234 G. D. Walcott — The Taconic System of Emmons. 



but in Vermont Mr. Wing makes the limestone superjacent 

 to the quartzite (loc. cit., p. 204). 



As all observers agree on the stratigraphic position of the 

 quartzite series the paleontologic evidence of the age of the 

 terrane, formed by that series, will be now considered. 



The Professors W. B., and H. D. Rogers, Edward, and C. H. 

 Hitchcock, James Hall, Dr. W. W. Mather and Professor Jas. 

 D. Dana have all held the opinion that the quartzite (Terr. 

 No. 1 ) should be referred to the Potsdam horizon and, from 

 its stratigraphic position, the tentative reference was in accord- 

 ance with the facts known ; but, as Professor Dana has said 

 (ante), the question of age can only be answered by decisive 

 fossils in the quartzites of Vermont. 



During the progress of the geological survey of Vermont, a 

 few fossils were found in the quartzite. On page 356, of the 

 Geological Report, vol. i, 1862,* it is stated : that besides Scol- 

 ithus, a straight-chambered shell occurs in a hyaline quartz, on 

 the west side of Lake Dunmore, and a species of Lingula in 

 Starksboro, near Rockville ; and, on page 357 : " In the south- 

 western part of Woodford there seem to be traces of organisms 

 resembling bivalve shells, about the size of a three-cent piece. " 

 I have, through the courtesy of Professor Dana, examined two of 

 the specimens referred to, that are now in the collection of the 

 Peabody Museum, at New Haven, and I rind the " Modiolopsis- 

 like shell" to be Nothozoe Vermontana, and the straight- 

 chambered shell to be, to all appearances, a cast of Hyolithes 

 communis, a Middle Cambrian species. 



Professor B. K. Emerson kindly sent to me for examina- 

 tion the specimens from the Amherst college collection men- 

 tioned in the Geology of Vermont, and which were collected at 

 Salisbury, Vt. I find one to be Nothozoe Vermontana and the 

 other species to be a cast of Hyolithes communis, or a closely 

 allied species. In a small collection of fossils, received from 

 Professor H. M. Seely, of Middlebury college, Vermont, who 

 found them in quartzite bowlders on the west slope of Sunset 

 Hill, near Lake Dunmore, there occurs the Nothozoe Yerrnon- 

 tana described as " from the Potsdam sandstone,"f and, with 

 it, heads of a species of Olenellus unclistinguishable from 0. 

 Thonvpsoni of the Georgia formation in Franklin County, Ver- 

 mont ; and in other specimens of the quartz rock, collected at 

 the same locality and containing N. Vermontana and O. 

 Thompsoni, a species of Hyolithes occurs that is undistinguish- 

 able from H. communis. 



An investigation of the reported localities of fossils, made by 

 the writer in June and July, 1887, resulted in the discovery 



* Dated 1861, but issued in 1862. 



f Bull. Am. Mus. Nat. Hist., vol. i, p. 145, 1884. 



