No. 1.] DAWSON— GEOLOGY OP NOVA SCOTIA. - 7 



6. Strophomena rhomhoidalis. Fmgments from Nictaiix. 



7. Spirifer arenosus, Hall. This characteristically Oriskany 

 epecies is so abundaot at Nictaux, that though the specimens are 

 imperfect, I think its recognition certain. It is found also at 

 Bear River. 



8. Spirifer arrectus, Hall, or allied, also an Oriskany species. 

 — Nictaux. 



9. Spirifer Nictavensis. This is the most abundant species 

 in the Nictaux 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 mucronafus of the Devonian. It is 

 perhaps still nearer to S. Ga.yjensis of Billings from the Gasp^ 

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

 low as the Medina. — Nictaux and Bear River. 



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

 apparently represented by casts of the interior. — Nictaux. 



11. Leptocelia flaheUites, Hall. This littlo >hell is abundant 

 at the base of the Devonian in Gaspe, and the same or a very 

 similar species is found at Nictaux and Bear River. 



12. RenfeUitria ovoides, Eaton. A very characteristic Lower 

 Devonian species at Gaspe and elsewhere. — Nictaux. 



13. Megnmhonia, very near to the Oriskany species M. lamel- 

 losa, Hall. — Nictaux. 



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

 A. textilis, but too imperfect for determination. — Nictaux. 



15. Tentacidites, not distinguishable from T. elongatus, Hall, 

 of the Lower Helderberg. — Bear River. 



16. I group together a Plati/ceras very near to an Oriskany 

 species, a Belleroplion 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 formation. 

 I may notice in farther evidence of the facts stated above, that 

 slates very near to 'the ore-bed hold Upper Arisaig (Helderberg) 

 specie-^, so that there appears to be a passage from the Lower 

 Helderberg to the Oriskany, which would be quite natural ; 

 whereas the juxtaposition of Lower Helderberg and Medina 

 fossils could take place only by extensive faulting or the absence 

 of all the intermediate formations. It is also to be observed 



