THE BRIAN, OR DEVONIAN. 21 



9. Spirifer Nictavcnsis. This is the most abundant species iu the Ni(;taux 

 ore, some specimens of which are crowded with it, and it is also found at Bear 

 River. It is very nearly allied to the well-known Spirifer mucronalus of the 

 Devonian. It is perhaps still nearer to S. Gaspensis of Billings from the Gaspe 

 sandstone ; and no Spirifers of this type are known to extend so low as the 

 Medina. 



10. Orthis hipparionyx, Hall. A characteristic Oriskany shell. 



11. Leptocclia flahcllitcs, Hall. This little shell is abundant at the ba.se of 

 the Devonian in Gaspe, and the same or a very similar species is found at 

 Nictaux and Bear River. 



12. Bcnsellccria ovoidcs, Eaton. A very characteristic Lower Devonian 

 species at Gaspe and elsewhere. 



13. Megamhonia, very near to the Oriskany species M. lamdlosa, Hall. 



14. Avicula, a large species of the type of the Oriskany species A. tcxtilis, 

 but too imperfect for determination. 



15. Tcntaculites, not distinguishable from T. elongatus, Hall, of the Lower 

 Helderberg. 



16. I group together a Platyccras very near to an Oriskany species, a Bellero- 

 plion and an Orthoceras, found at Nictaux. 



Fragments in my collection indicate several other .species ; but the 

 above I hold to be amply sufficient to prove that the beds in which 

 they occur are approximately of the age of the Oriskany sandstone, 

 and cannot possibly be so old as the Clinton or Medina formation, to 

 which they have been, as I believe incorrectly, assigned. 



It is also to be observed that, independently of the determination 

 of species, the whole aspect of the fauna of the Nictaux iron bed, in 

 its abundance of large ribbed spirifers, of large strophomenoid shells, 

 and of great lamellibranchiate species, is different from that of the 

 Clinton or Medina, and on the contrary reminds an observer forcibly 

 of the Oriskany sandstone of Gaspe and of Western Canada. It is 

 almost equally distinct from that of the (Helderberg) Silurian red 

 hematite of Pictou. 



It should, however, be distinctly understood, that, in so far as I 

 have held Erian rocks to exist at Nictaux and Bear River, the upward 

 extension of sucli rocks is limited to the Oriskany sandstone, and 

 should any one hold that this formation may be included in the 

 Silurian, I have no objection ; though I think that on physical 

 grounds and by virtue of its close relationship with the overlying 

 formations, it has quite as good claims to be correlated with the 

 Lower Erian. 



Questions whicli have been raised respecting the age of tiic granite 

 of Nictaux and its vicinity can only be discussed profitably on the 

 ground. My notes of many years ago assure me, however, tliat 1 

 have traced the Lower Devonian beds into contact with the granite 



