X] 



RHIZOME OF CALAMITES. 



323 



is another feature to which attention must be drawn. On the 

 casts shown in -fig. 82 there is a circle of small oval scars 

 situated just below the nodes, these are clearly shown at 

 c, c, c. Each of the scars is in reality a slight projection 

 from the upper end of an internodal ridge. As the ridges 

 correspond to the broad inner faces of medullary rays, the 



Fig. 82. Branched rhizome of Calamites. J nat. size. 

 C, C, nodes showing casts of infranodal canals. 

 From a specimen in the Manchester Museum, Owens College. 



21—2 



