J. D. Dana — Brief history of Taconic ideas. 415 



The system thus had Cambrian at top and Cambrian at 

 bottom. In the chapters on the granular quartz, doubts about 

 its true position are admitted ; but the decision as to its being 

 the oldest in the series is not recalled. 



The Keport has an appendix on pages 109-112 ; and its 

 closing sentences, which show wavering opinions, are import- 

 ant in the history. After saying that in this system of beds, 

 made when the earth's condition earliest admitted of it, " we 

 find the earliest beings which had life and vitality," he adds 

 (p. 112) : " We do not feel confident that it is in the earliest 

 of these deposits that we have discovered fossils. Mr. James 

 Hall, however, informs me that he found the Scolithus, a tubu- 

 lar polyparian, in the most easterly mass of the granular quartz. 

 On visiting the place as described to me, I was not successful 

 in my search for this fossil, but at another locality I found 

 what appears to he an orthoceratite. The fossils, however, are 

 more abundant in the newer rocks of this system ; and they 

 belong to beings of an extremely delicate construction, as the 

 reader may see by reference to our description in another part 

 of this report." The orthoceratite is not figured or again 

 mentioned. 



Prof. Emmons was led to make the "Black slate" of Bald 

 Mountain either " a distinct rock, or merely the upper portion 

 of the Taconic slate" by his discovery "during the early 

 part of September," 1844, of a fossil " which resembles closely 

 an Annelide," and the finding at the same place by Dr. Finch 

 of two species of trilobites. The trilobites were named Atops 

 trilineatus u evidently allied to Triarthrus Beckii, so abundant 

 in the Utica slate " and Elliptocephala asaphoides, and figures 

 are given on pages 64, 65. The " Taconic slate " of eastern 

 New York, including the Hoosic slate, and occupying, as he 

 says, " almost the whole of Columbia, Rensselaer and Wash- 

 ington Counties and reaching to St Albans," was also put with 

 the upper fossiliferous part of the system (pp. 67 to 71), 

 because of the discovery of Annelid markings chiefly, Nereites 

 and Myrianites. 



These new New York fossils had claims to a place in the 

 first volume of Prof. Hall's Paleontology of New York, which 

 was published nearly two years later, the preface bearing the 

 date September 1, 1846. The author made the Atops identi- 

 cal with Triarthrus BecJcil and hence referred both trilobites, 

 together with the slates, to the Hudson river group; and the 

 Elliptocephalus was referred to the genus Olenus. In the 

 same month, the question of identity was discussed at the 

 meeting of the Association of Geologists and Naturalists and a 

 committee of investigation appointed for its consideration 



