DEVONIC PERIOD 543 



are 7,000 feet of sandstones devoid of marine life, which elsewhere in 

 Quebec contain Old Eed fishes, the same types of fishes also occurring in 

 New Brunswick and Nova Scotia. This Acadian highland, with its tur- 

 bid rivers, continued well into Mississippian time. 



Helderbergian. — In. North America, during the Helderbergian, there 

 were two distinct faunal provinces, an Atlantic and a Pacific. The latter 

 is little known; it was first described by Walcott in his report on the 

 Eureka district, Nevada, but was not distinguished as Helderbergian from 

 the higher Devonic. There is little in this province to suggest the Bohe- 

 mian, or even the eastern Eussian Lower Devonic described by Tscherny- 

 schew. In southeastern Alaska, Kindle 162 has discovered Helderbergian 

 faunas that clearly have Bohemian-Mediterranean connections, as shown 

 in the abundance of Hercynella. It is probable that these Alaskan waters 

 had direct connection with those of the Arctic ocean, for at capes Frazier 

 and Leidy among other forms occur AnopJotheca concava, Spirifer per- 

 lamellosus, Stropheodonta beclcii ?, and Strophonella headleyana. At 

 cape Chidly, Labrador, Low has recently collected Gypidula galeata and 

 the very diagnostic Leptcenisca concava. 



Helderbergian faunas are known in the Saint Lawrence trough on 

 Gaspe peninsula ; at Dalhousie, New Brunswick ; northern Maine, and on 

 Saint Helens island, opposite Montreal. The earliest of these faunas 

 much remind one of those of the New York basin, but the higher elements 

 on Gaspe and at Dalhousie pertain to a distinct subprovince. The Spiri- 

 fer macropleura fauna does not seem to have penetrated beyond Square 

 lake, Maine. These northeastern Lower Devonic faunas are described in 

 detail by Clarke, 163 one volume having appeared in 1908, another in 1909. 



In their typical development the Helderbergian faunas occur in the 

 New York basin, and were described many years ago by James Hall. 

 These faunas can be traced in the Appalachian trough as far south as cen- 

 tral Virginia, and must have entered this basin by way of the New Jersey 

 straits. The same fauna, but slightly changed, is again met with on the 

 west side of the Cincinnati axis, first in southwestern Illinois and then 

 across the Mississippi river in Missouri. In western Tennessee it is well 

 developed as the Linden formation, and the identical fauna is again found 

 in the Hunton deposits in the Arbuckle mountains of Oklahoma. This 

 southwestern Helderbergian life of Gulf derivation practically coincides 

 with that of New York, and both belong to the southern Poseidon realm, 

 connecting with Bohemia and the Mediterranean. 



162 Kindle : Journal of Geology, vol. 15, 1907. 



163 Clarke : Memoir no. 9, parts 1-2, New York State Museum, 1908, 1909. 



