Geology and Natural History. 215 
with perfect and the finest examples of what are presumed to be 
“casts of the canal system ”—are present in calcite, occupying the 
crevices of a large crystal of spinel. The fact of itself conclusively 
settles their purely mineral origin. 
the Oil-bearing Rocks of Ohio and West Virginia; b 
A. J. Warner. (Communicated.)—In an article on the “Oil- 
bearing Limestones of Chicago,” in the June number of this Jour- 
nal, by Prof. T. Sterry Hunt, this author remarks that. “much of 
the petroleum of Pennsylvania, Ohio, and the adjacent regions, is 
Indigenous to certain sandstones in the Devonian and Carbonifer- 
rocks,” 
It is now well ascertained that the heavier lubricating oils, pro- 
duced along the well known uplift in West Virginia, are found 
s of th i 
same district is principally found about three hundred and fift 
feet below the Coal-measure conglomerate, or in the Upper Devo- 
f S$ 
gravity, is found phage get the sandstone stratum, which forms 
in 
emp) contain Calamites 
e 
A 
Why is it limited strictly to these sharp anticlinal belts ? The evi- 
ence seems abundant, that, at least in the dist 
lime- 
t Genesee and Marcellus slates, or the deeper Silurian 
Stones, may, perhaps, be yet a question ; but facts which Loeercl 
quire too much space to ask for here, favor the view of the ne 
Source in the bituminous shales. 
Marietta, Ohio, July 12. 
