of North America with those of Europe. 367 
the justice of this classification.* To return to the state of New 
ork; the occurrence of the fragment of a fish of the genu$ 
Asterolepis, found by Mr. John Gebhard in the Schoharie grit, 
induces us still further to lower the inferior limits of the Devo- 
nian system. But should we rest there? or must we yet include 
the Oriskany sandstone? After much hesitation we adopt the 
last, from two reasons; the first is, that following the opinion of 
Mr. Hall, the deposit of the Oriskany sandstone appears to have 
been preceded by a violent movement of the waters, which de- 
nuded the soil and wore the depressions where it accumulated ; 
the second is, that certain'fossils have also some analogy with the 
Devonian fossils, such as that mass of large Spirifer totally un- 
known in the Silurian rocks. 'T'wo among them, of which we 
ve seen only the casts, remind us of the Spirifer cultrijugatus 
S. macropterus of the schists of the Eifel. 
The Devonian system being thus constituted, we must seek to 
Place in parallelism its different stages with those of Europe. It 
18 incontestible that the red sandstone which forms its superior 
, and which is so powerful on the frontiers of the states of 
New York and Pennsylvania, is upon the same horizon as the 
old red sandstone of Scotland and Wales. It is here also a 
local formation, more powerful than extensive, and which con- 
only the remains of fishes.t The groups of Chemung, 
*“We may 
the Ludlow rocks.” ; 
t We regret that M. de Verneuil should not have given more importance to this 
red sandstone, instead of merely representing it as the terminal grou of the De- 
the termination of the Hudson River group, there is perhaps nowhere else in the 
entire Paleozoic series so complete a change in the lithological and Paleozoic fea- 
i F the Chemung group. Over a consid- 
erable extent in New York and Pennsylvania, the Chemung group is succeeded 
coarse sandstone or conglomerate, which lies at the base of the red sandstone. 
8 change is equally great with that which took place at the production of the 
Oneida cong rate, and the mass forms a distinct topographical feature in the 
southern -of New York, and in parts of Pennsylvania. At the same time all 
the petder® organic forms of the Chemung group have become extinct, and we 
. 
a 
a= 
° 
