26 WATSON, Two Species of Lepidodendvon Harcourtii. 



Plate II. 



Fig. 4. Almost radial section of a leaf base of L. Hickii x (30). 

 The centre of the stem lies to the W. 



The leaf trace is seen in the outer cortex, with the 

 parichnos below it. The parichnos is also seen emerging 

 to the leaf scar on the East. 



The ligular pit is seen in longitudinal section and the 

 dark tissue at its base and extending to W. over the leaf 

 trace is transfusion tissue of short tracheids. 

 A 201 C. D. Watson collection. 



Fig. 5. Oblique tangential section of an isolated leaf base, 

 almost certainly belonging to L. Hickii x (30). 



The patch of tissue around which transfusion tracheids 

 are concentrated is the base of the ligule. 



The two large patches of tissue, composed of stellate 

 cells, are the two "pits" filled with aerenchymatous tissue 

 in connection with the parichnos. 



The parichnos itself is seen just within the west patch. 

 A 201. D. Watson collection. 



