THE ERIAN OR DEVONIAN FORESTS. 



107 



In order that distinct notions may be conveyed as to the geo- 

 logical horizons of the species, I may state that the typical Devonian 

 or Brian series of Canada and New York may be divided in descend- 

 ing order into — 1. The Chemung group, including the Chemung and 

 Portage sandstones and shales. 2. The Hamilton group, including 

 the Oedesee, Hamilton, and Marcellus shales. 3. The Comiferous 

 limestone and its associated beds. 4. The Oriskany sandstone. As 

 the Comiferous limestone, which is the equivalent of the Lower 

 Carboniferous limestone in the Carboniferous period, is marine, and 

 affords scarcely any plants, we may, as is usually done for like pur- 

 poses in the Carboniferous, group it with the Oriskany under the 

 name Lower Brian. The Hamilton rocks will then be Middle Brian, 

 and the Chemung group Upper Brian. In the present state of our 

 knowledge, the series, may be co-ordinated with the rocks of Gaspe, 

 New Brunswick, and Maine, as in the following table : 



Sabdivisionfi. 



Dpper 



DeTonian or 



Erian. 



Middle 



Devonian or 



Erian. 



Lower 



Devonian or 



Erian. 



New York 



and 



Western Caoilda. 



Chemung 

 Group. 



Hamilton 

 Group. 



Comiferous 



and 



Oriskany 



groups. 



Oaep6 



and BaydeB 



Chaleiirs. 



Upper 



Sandstones. 



Long Cove, &c. 



Scauminac 



Beds. 



Middle 



Sandstones. 



Bois Brul6, 



Cape Oiseau, 



&c. 



Lower 

 Sandstones. 

 Gasp6 Basin, 

 Little GaspS, 



&c. 



Campbellton 



Beds. 



Southern 



New 

 Brans wick. 



Mispec Group. 

 Shale, Sand- 

 stone, and 

 Conglomer- 

 ate. 



Little R.Group 

 (includiiig 

 Cordaite 

 Shales and 

 Dadoxylon 

 Sandstone}. 



Lower Con- 



mera 



&c. 



Coast 



of 

 Maine. 



Perry Sand- 

 stones. 



It may be proper, before closing this note, to state the reasons 

 which have induced me to suggest in the following pages the use of 

 the term " EEiiN," as equivalent to " Devonian," for the great sys- 

 tem of formations intervening between the Upper Silurian and the 

 Lower Carboniferous in America. 1 have been induced to adopt 

 this course by the following considerations : 1. The great area of 



