120 



THE GEOLOGICAL HISTORY OF PLANTS. 



FIG. 43. Lepidodendron corrugatum, Dawson.a tree characteristic of the 

 Lower Carboniferous. A, Restoration. B, Leaf, natural size, c, Cone 

 and branch. D, Branch and leaves. E, Various forms of leaf-areoles. 

 F, Sporangium, i, L, M, Bark, with leaf-scars. N, Bark, with leaf- 

 Bcars of old stem, o, Decorticated stem (Knorria). 



