t8 studies in fossil botany 



The most conspicuous markings on a Calamitean cast 

 consist of longitudinal ridges and furrows, the former 

 usually broader than the latter. The specimens are 



Fig. 3. — Catamites Suckowii. Medullary cast, bearing the cast of a branch larger 

 than that of the main stem, i.e., the prints of the infranodal canals below a node. 

 \ of natural size. From a photograph by Mr. R. Kidston, F.R.S.E., taken from a 

 specimen in his collection, found at the Oaks Colliery, llarnsley ; Middle Coal- 

 measures. 



distinctly jointed, the joints being marked by zigzag 

 commissural furrows. It has always been recognised 

 that these joints represent the nodes. Often, but not in- 



