266 PALAEOZOIC TIME — DEVONIAN AGE. 



1. OKISKANY PEKIOD (8). 

 I. Rocks : kinds and distribution. 



The Oriskany sandstone is named from the town of Oriskany, in 

 Oneida co., N.Y., one of its localities. The rocks are mostly rough 

 sandstones. They are 30 feet thick in this region, and thin out both 

 to the east and west, being barely recognizable on the Hudson, and 

 to the west extending as far as Cayuga Lake. West of the Appa- 

 lachians, beyond New York, the formation is for the most part un- 

 known ; but along the Appalachian region it stretches south through 

 Pennsylvania, Maryland, and Virginia, having a thickness of several 

 hundred feet, and retaining its rough aspect ; and it also occurs to 

 the north at Gaspe, near the Gulf of St. Lawrence. In the Eastern 

 border region, the formation has been identified by its fossils in 

 Maine between Parlin Pond and the Aroostook Eiver, and else- 

 where ; also in Nova Scotia. 



The sandstone consists either of pure siliceous sands, or of argillaceous sands. 

 In the former case it is usually yellowish or bluish, and sometimes crumbles 

 into sand suitable for making glass, as at Vernon, N.Y. In the latter it is of 

 a dark brown or reddish color, and was once evidently a sandy or pebbly mud. 

 In some places it contains nodules of hornstone. The beds are often distin- 

 guished by their rough and hard dirty look (especially after weathering) and 

 the large coarse calcareous fossil shells, — species of Brachiopods. The sandstone 

 occurs in Cayuga co., Canada West, and also on the Mississippi in Illinois. In 

 St. Genevieve co., Missouri, the rock is a limestone (Shumard). 



The Nova Scotia strata of this epoch occur at Nictaux and on Moose and 

 Bear Rivers. They include a thick band of fossiliferous iron-ore, which is an 

 argillaceous deposit at Nictaux, but, owing to partial metamorphism, is a 

 magnetic iron-ore on Moose River. 



II. Life. 



1. Plants. 



No remains of land-plants have been yet observed. Considering 

 the nature of the rock, the negative evidence bears strongly against 

 the existence of land-vegetation in the Oriskany period. 



The rocks of Gaspe, according to Dawson, contain relics of Coniferous wood 

 and other plants, and are pronounced to be probably Lower Devonian ; but the 

 particular period to which they belong is not kitown. They are mentioned beyond, 

 under the Hamilton period. According to the same author, remains of land- 

 plants occur in a limestone at Gaspe, which "seem," he observes, "to indicate 

 the occurrence of Psilophyton and Noeggerathia or Oordaites in the Upper Silu- 

 rian of Canada." 



