WATER-WORN COAL PEBBLES 77 
granting such to be the case it would hardly seem possible that 
sufficient time would have elapsed for the coal bed some 60 feet 
below or even for other carbonaceous deposits still lower down 
in the coal measures to yield more than a lignite. It would seem 
to me therefore that these carbonaceous pebbles were originally 
transported not as a coal but as chunks of lignite or wood. It 
seems to me also more reasonable to conclude that they were in the 
form of lignite rather than in a less carbonized form, since many 
of the pebbles are nearly spherical and not flattened as would be 
expected if the pebbles were formed of wood. 
Occurrences of water-worn pebbles of coal in the rock are 
doubtless well known to many geologists, but it has not been my 
pleasure to see deposits with such large pebbles elsewhere. 
