6 BUTTERWORTH, Leof-sheath of Calamite. 



{b) Although the specimen which I have found of the 

 leaf-sheath surrounding the node of a Calamite is not 

 perfect, still it shows considerable detail of the internal 

 structure of the Calamite at the node, as well as some of 

 the structure at the base of the sheath, while the specimen 

 found by Mr. Parker, of Rochdale, though only a cast in 

 coal shale, shows considerable detail of the outer part of 

 the sheath. The wood-cut shows the leaf-sheath as seen 



in Mr. Parker's specimen, the drawing being the actual 

 size of the fossil. It will be seen that the sheath extends 

 about one-third of the total length of the leaves. The 

 leaf-sheath is separated from the vascular cylinder by a 

 band of cortical tissue of which the structure cannot be 

 made out. In the central cylinder, however, the vascular 

 bundles can be seen branching, and thus indicating that 

 the fossil is split through the node, where the leaf-sheath 

 must have been inserted. The insertion of this leaf-sheath 

 at the node of the stem is also very clearly seen in the 

 sections cut through the fragment which I have found 

 myself 



A leaf-sheath in a Calamite is figured in Seward's 

 Fossil Plants, Vol. I., p. 260. It, however, is less distinct, 

 and differs considerably in its extent and proportions 

 from that figured in this paper. 



