LL, Lesquereuz on the Coal Formations of N. America. 383 
_ The occasional appearance of petrified trees, standing imbedded 
in sandstone, does not give evidence of a rapid formation either 
and thus preserve the stumps from decomposition an by-and- 
by these may be converted to stone. ‘The bald cypress and other 
shore under ten feet of water. Whole forests of those trees 
have been imbedded ina standing position in the marshes around 
ae the geological records of 
the carboniferous period any indication of a rapid process of 
formation, either cataclysmie or abnormal, and I rea ily admit 
that each bed of coal with its accompanying strata of fire-clay 
and shales has required for its formation a period of time as 
long as any of our recent geological divisions.* 
The question concerning the existe 
* Thus, if a peculiar nomenclature fora classification of the different strata of 
the old red sandstone, of the subconglomerate coal, and of the Millstoue-grit is ad- 
missible, the process of division should be extended to each bed of the coal- 
measures, 
