XIII.] GEOGNOSY OF THE APPALACHIANS. 257 



was described by him as corresponding to the Oneida or 

 Shawangunk conglomerate, while the limestones and shales 

 of the vicinity, which were supposed to underlie it, were re- 

 garded as the representatives of the Trenton, Utica, and Hud- 

 son River formations.* By following these rocks along the 

 western base of the Appalachians into Vermont and Massa- 

 chusetts, they were found to be a continuation of the Taconic 

 system, which Sir William was thus led to refer to the upper 

 half of the Champlain division, as had already been done by 

 Professor Adams in 1847.t As regards the crystalline strata, 

 of the Appalachians in this region, he, however, rejected the 

 view of Emmons, and maintained that put forward by the 

 Messrs. Eogers in 1841; namely, that these, instead of being 

 older rocks, were but these same upper formations of the 

 Champlain division in an altered condition ; a view which was 

 maintained during several years in all of the publications of 

 those connected with the geological survey of Canada. 



This conclusion, so far as regards the age of the unaltered 

 fossiliferous rocks from Quebec to Massachusetts, was supposed 

 to be confirmed by the evidence of organic remains found in 

 them in Vermont. Mr. Emmons had described, as character- 

 istic of the upper part of the Taconic system, two crustaceans, 

 to which he gave the names of Atops trilineatus and Ellipto- 

 cephalus asaphoides ; the other fossils noticed by him being 

 graptolites, fucoids, and what were apparently the marks of 

 annelids. In 1847 Professor James Hall, in the first volume 

 of his Paleontology, declared the Atops of Emmons to be 

 identical with Triarthrus (Calymene) Beckii, a characteristic 

 fossil of the Utica slate ; while the Elliptocephalus was re- 

 ferred by him to the genus Olenus, now known to belong to 

 the primordial fauna of Sweden, where it is found in slates 

 lying beneath the orthoceratite limestone, and near the base of 

 the palaeozoic series. Although, as it now appears, the geologi- 

 cal horizon of the Olenus slates was well known to Hisinger, 



* Geological Survey of Canada, 1847-48, pp. 27, 57 ; and American Jour- 

 nal of Science (2), IX. 12. 



t American Journal of Science (2), V. 108. 



