12 



are not limited to the surface of the pith, but occur on the 

 woody cylinder as well. Mr. Bain has observed in one 

 instance, what seems to be an outer envelope which would 

 indicate a thick bark, but its structures are crystalline, 

 and it may be merely a concretionary covering. 



The leaves and branchlets in fig. 5 have been found 

 by Mr. Bain in such relation to the debris of Tylodendron, 

 that he regards them as belonging to it. They certainly 

 differ from those of any of the known species of Walchia, 



FIG. 5. Leafy ^branch of Tylodendron and leaf enlarged t 

 (Drawn by Mr. Bain.) 



