36 C. Lyell on the origin of Coal-fields. 
subaqueous deposits. Nevertheless we must not indulge too san- 
uine expectations on this head, when we recollect that no fossil 
vertebrates of a higher grade than fishes, or any land-shells, have 
yet been met with in the Oolitic coal-field of the James River, 
near Richmond, Virginia, a coal-field which has been worked 
extensively for three-quarters of a century. The coal alluded to 
is bituminous, and as a fuel resembles the best of the ancient coal 
of Nova Scotia and Great Britain. The associated strata of sand- 
secondary rocks does not imply, as we might have anticipated, 
conditions the most favorable to our finding therein creatures of 
a higher organization than fishes. 
In breaking up the rock in which the reptilian bones were en- 
tombed, a small fossil body resembling a land shell of the genus 
Pupa, was detected. As such it was recognized by Dr. Gould of 
Boston, and afterwards by M. Deshayes of Paris, both of whom 
carefully examined its form and stration. When parts of the 
surface were subsequently magnified 250 diameters, by Professo 
Quekett of the College of Surgeons, they were seen to exhibit 
ridges and grooves undistinguishable from those belonging to the 
striation of living species of land-shells. The internal tissue also 
of the shell displayed, under the microscope, the same prismatic 
and tubular arrangements which characterize the shells of living 
mollusca. Sections also of the same showed what may be part 
of the columella and spiral whorls, somewhat broken and dis- 
torted by pressure and crystallized. ‘The genus cannot be made 
out, as the mouth is wanting. If referable to a pupa or any allied 
genus it is the first example of a pulmoniferous mollusk hitherto 
detected in a primary or paleozoic rock. 
ir Charles next proceeded to explain his views as to the origin 
of coal-fields in general, observing that the force of the evidence 
in favor of their identity in character with the deposits of modern 
deltas, has increased, in proportion as they have been more closely 
studied. ‘They usually display a vast thickness of stratified mud 
and fine sand without pebbles, and in them are seen countless 
stems, leaves, and roots of terrestrial plants, free for the most part 
from all intermixture of marine remains, circumstances which 
imply the persistency in the same region of a vast body of fresh 
water. ‘T'his water is also charged like that of a great river with 
an inexhaustible supply of sediment, which had usually been 
3 
