114 Scientific Intelligence. 
This coal field, which is about twenty miles long from north to south 
and from four to twelve in breadth from,east to west, is situated twelve 
miles west of Richmond in Virginia, in the midst of a granitic region. 
The rocks consisting of guartzose grits, sandstones, and shales, pre- 
Git the ordinary coal measures of Europe. 
few however being allied to fossils of the European trias. 
ight position of the Calamites and Equisete Mr. Lyell 
infers that the vegetables which produced the coal grew on the spots 
oal is now found, and that the strata were formed during 
the continued subsidence and repeated submergence of this part of Vir- 
ginia. The shells consist of countless individuals of a species of Pos- 
sidonomya, much resembling P. minuta of the English trias. The 
fossil fish are homocercal and differ from those previously found in the 
new red sandstone (trias?) of the United States. Two of them be- 
long to a new genus and one toa Tetragonolepis, and they are con- 
— by Prof. Agassiz and Sir P. Egerton to indicate the liassi¢ 
period. 
The analysis of the coal made by Dr. Percy and Mr. Henry, shows 
that it contains the same elements, carbon, oxygen, hydrogen and ni- 
trogen, in the same proportions as the older bituminous coal of Europe 
and North America. Alternating layers of crystalline coal, and others 
bserved in many p h 
Volcanic rocks (dikes and beds of intrusive greenstone) intersect the 
coal measures in several places, hardening the shale an altering the 
associated coal, the latter being in some places turned into a coke used 
The author concludes by expressing his opinion that the evidence of 
the fossils, although some of them belong to forms usually found in 
paper was next read, entitled, ‘* Descriptions of Fossil 
rugs J. F 
* For the memoir of Prof. Wm. B. Rogers, in which this conclusion Fes 
tained by the same arguments in 1842, see Report Assoc. Amer. Geol. and Nat-, 
1840-1842, p. 298. 
