330 C. SCHUCHERT — LOWEB HELDERBERG— ORISKANY FORMATIONS 



From the foregoing list it is seen that the Oriskany fauna of " divis- 

 ion 8 " of the Gaspe limestones has 47 species, of which 27 are not known 

 to occur elsewhere. The 20 species having wide distribution are, with 

 one exception, brachiopods, and 16 of these are Oriskany species, while 

 2 are Helderbergian and 2 are Onondaga forms. It is the brachiopods 

 that indicate the age of these Gaspe limestones. Of the 19 widely dis- 

 tributed forms, 12 occur in the Lower Oriskany and 14 in the Upper 

 Oriskany. The evidence, therefore, as far as numbers are concerned, 

 is non-committal as to which of the two Oriskany horizons " division 

 8 " should be referred. If the components of this fauna are analyzed, 

 the evidence is somewhat in favor of placing it in the Upper Oriskany. 

 This proof lies either in the degree of development or size of the species 

 when compared with the same forms in Upper Oriskany faunas. The 

 Campbell River locality indicates more definitely the Upper Oriskany 

 horizon. 



The reason that so many species are restricted to Gaspe is probably 

 to be found in the difference in the sediments, indicating deeper water. 

 In the Appalachian region the deposits are "almost always sandstones — 

 at least those from which the writer has seen fossils — while in Gaspe 

 limestones predominate. Corals and mollusks are rare in the Appa- 

 lachian faunas, while in the Gaspe fauna they give it a distinct facies. 



The great numbers of brachiopods common to Gaspe and the Appa- 

 lachian Oriskany show that the two areas had free communication, since 

 in their faunal aspect they are almost identical. In fact there is greater 

 diversity in the brachiopods of the Lower Oriskany of Tennessee and 

 New York, than in those of the Upper Oriskany of Gaspe, New York, 

 and Ontario. 



Nova Scotia, Canada. — In Nova Scotia, in the region of Nictau, the 

 Oriskany is present and is described by Sir William Dawson* as 

 follows : • 



" We reach a band of highly fossil iferons peroxide of iron, with dark colored, 

 coarse slates. . . . The fossils of the ironstone and the accompanying beds, 

 as far as they can be identified, are Spirifer arenosus, Stropheodonta magnified, Atrypa 

 wnguiformis [= Hipparionyx proximus], Strophomena depressa [— Lepisena rkomboi- 

 dalis\ y and species of Avicula, Bellerophon, Favosites, Zaphrentis, etc. These Pro- 

 fessor Hall compares with the fauna of the Oriskany sandstone. . . . The 

 most abundant fossil is Spirifer nictauvensis Dawson. 



" To the southward of the ore, the country exhibits a succession of ridges of slate 

 holding similar fossils, and probably representing a thick series of Devonian beds, 

 though it is quite possible that some of them may be repeated by faults or folds." 



* Acadian theology, 3d ed., 1878, p. 4!t ( J. 



