THE CARBONIFEROUS PERIOD. 171 



ing upright in the old Carboniferous swamps, were completely 

 hollowed out by internal decay, till nothing but an exterior 

 shell of bark was left. Often these hollow stumps became 



Fig. 110. Lepidodendron Sternbergii, Carboniferous, Europe. The central figure 

 represents a portion of the trunk with its branches, much reduced In size. The right- 

 hand figure is a portion of a branch with the leaves partially attached to It ; and the 

 left-hand figure represents the end of a branch bearing a cone of fructification. 



ultimately filled up with sediment, sometimes enclosing the 

 remains of galley-worms, land-snails or Amphibians, which 



