228 REPORT OF THE AMERICAN COMMITTEE. 
Devonian some tlilrty years after the latter was defined, it is not 
likely to take the place of Devonian, unless it can be shown to 
be an advantage to have a different nomenclature for the Geology 
of each continent. 
On the preceding page is a table of the classification and of the 
typical sections of the Erian as given in the above-mentioned 
paper, p. 11. 
§ 2. The Devonian Areas op North America. 
The sections of the Devonian rocks in North America present 
at least four distinct types of stratigraphy in their outcrops in 
different parts of the continent. The four areas blend somewhat 
at their borders, but in their central sections are very distinct. 
The four areas may be called the 
(1.) Eastern Border Area, including the outcrops of Gaspe, 
New Brunswick, Maine, and other places in Northern New 
England ; 
(2.) The Eastern Continental Area, including the New York 
and Appalachian tracts as far south as West Virginia, and ex- 
tending northwestward into Canada West and Michigan; 
(3.) The Interior Continental Area, typically seen in Iowa and 
Missouri, extending into Illinois and Indiana, and probably 
northward toward the valley of the Mackenzie River; and 
(4.) The Western Continental Area, best known through Hague 
and Walcott's studies of the Eureka, Nevada, sections. 
Each of these four areas presents sections of the Devonian, 
which in all the details of their stratigraphical, lithological and 
paleontological composition are different from each other. 
The Eastern Border Area. 
The typical eastern border section, as seen at Gaspe, is a heavy 
series of arenaceous shales, sandstones and conglomerates, gray, 
drab and red in color, of some 7000 feet in thickness. It lies upon 
2000 feet of limestone, which holds, in the upper part, fossils of 
upper Silurian age. These are regarded by Billings as of Hel- 
derberg types. The first thousand feet of the sandstone shows a 
rich flora, and, by some traces of invertebrate fossils, is known 
to date back as early as the age of the Oriskany sandstone. The 
first 5000 feet of the sandstone represents the interval from the 
top of the Silurian to the top of the Chemung series of the New 
