SKETCH OF EBENEZER EMMONS. 409 



the State of New York, and in the organization of the staff for 

 carrying on that work Dr. Emmons was appointed by Governor 

 Marcy to the charge of the second district, which included the 

 northeastern counties of the State. This district was chosen by 

 Dr. Emmons as a field more especially interesting to him on 

 account of its mineral localities and minerals, and giving him a 

 field more congenial to his tastes and experience. He made the 

 public acquainted with the Adirondack region and named its 

 principal mountains. In 1837 he named, described, and classified 

 the celebrated Potsdam sandstone. Among the other rocks and 

 divisions to which he gave a name or a place in geology are the 

 Chazy limestone, black marble of Isle la Motte, Lorrain shales, 

 Champlain group, Ontario group, Helderberg series, and Erie 

 group. During the progress of this survey, also, he made the 

 important discovery that is most closely associated with his name. 

 In 1842 he pointed out a great system of stratified rocks under the 

 Potsdam, which he called the Taconic System. This announce- 

 ment brought upon him a storm of contradiction and ridicule, 

 and for a time he was scientifically ostracized. Subsequent dis- 

 coveries by the Canada Survey, and by Barrande, in Bohemia, 

 however, as well as the investigations of later eminent geologists, 

 have completely sustained him. In propounding the term Ta- 

 conic * System Prof. Emmons was following the instruction and 

 views of his teacher. Prof. Amos Eaton, who promulgated his 

 opinions regarding the age of these rocks in his lectures at Wil- 

 liams College from 1817 onward ; and subsequently in his lectures 

 at the Rensselaer School to the end of his life, although never 

 having published any satisfactory account of the relations of these 

 rocks to the formations above or below them. 



Two years later Dr. Emmons described the primordial fauna, 

 thus preceding the celebrated discoveries of Barrande, who rec- 

 ognized the priority of Emmons in the following courteous lan- 

 guage : 



" In comparing these dates it is clear that Dr. Emmons was 

 the first to announce the existence of a fauna anterior to that 

 which had been established in the Silurian System as characteriz- 

 ing the Lower Silurian Division, and which I have named the 

 Second Fauna. It is, then, just to recognize the priority, and I 

 think it all the more fitting to state it at this time, that it has not 

 hitherto been claimed." 



Prof. Emmons's Report on the Second District of the New York 

 Geological Survey was published in 1842. In the autumn of that 

 year his colleagues presented his name to Governor Seward as a 

 proper person to act as custodian of the collections of the geologi- 



* From the Tashkanic Mountains. 



'o 



VOL. XLVIII, 28* 



