10 NEW YORK STATE MUSEUM 



literature renders it all the more conspicuous as an infraction of the law and of the rights 

 of the men who first proposed it. In the face of Champlain, 1842, the term Ordovician 

 has no standing. 



2 Ontario. Vanuxem placed the base of the Ontario division at the "gray 

 sandstone," Hall and Emmons at the Medina, Mather at the Shawangunk grit. 

 Vanuxem and Hall terminated the above division with the Niagara, Emmons included 

 the Salina and waterlime. Growing evidence fully indorses Emmons's view as to the 

 termination of the group and period with the clearing of the Salina sea. 



3 Canadian. This term has the prestige of time and priority. 



4 Mohawkian (new). Conrad and Vannxem made use of the term, Mohawk 

 limestone, for certain of the calcareous layers beneath the Trenton, but they differed 

 so widely in their application of the term that in the summation of their results, the 

 geologists decided to abandon it. The name is here revived with a broader mean- 

 ing. The valley and watersheds of the Mohawk river afford typical exposures of 

 all members of the group. 



5 Cincinnatian. The formations of the Neochamplainic are not as completely 

 developed in the state of New York as in Ohio and Indiana. In the latter sections 

 the Lorraine fauna is represented, but is followed above by the well defined fauna of 

 the Kichmond beds. Probably in no other region is the succession of these faunas 

 so complete as about Cincinnati, and this fact justifies the recognition of the term 

 Cincinnatian, which already has historic value. For a full description of the series 

 by Winchell and Ulrich, see Geol. and nat. hist. sur. of Minn. 1897. v. 3, pt 2, 

 p. 101-5. 



6 Oswegan. This name is appropriate on account of the widespread occurrence 

 of the Oneida and Medina formations in Oswego county, N. Y. Vanuxem employed 

 the term, Oswego sandstone, for the formation subsequently and by common consent 

 called Medina sandstone. In reviving the name, though with a broader meaning 

 than in its original use, it derives its title from its early date. 



7 Niagaran. In the sense suggested by Prof. Dana. 



8 Cayugan (new). The divisions of this group are knit together by lithologic 

 and faunal characters and are distinctly Ontario. The outcrops are typically exposed 

 about the north end of Cayuga lake, N. Y. 



9 Helderbergian. The present state of our knowledge does not permit the use 

 of the term, Helderberg, in its original scope. The Helderberg division was 

 made to embrace formations now regarded as constituting the lower and part of 

 the middle Devonic. We propose to restrict the term Helderbergian to the forma- 

 tions currently known as Lower Helderberg, excluding the Tentaculite limestone. 



