Manchester Memoirs, Vol. hi. (191 2), No. 17. 7 



the ridge of leaf-scars. The upper of the two furrows 

 may be the elh'pse (or two elh'pses) of the leaf-scars, 

 distorted by the pressure of the branches. This supposi- 

 tion is strengthened by the occasional occurrence of fine 

 punctuations, P', {Plate) in the upper furrow, very closely 

 resembling the pits in the leaf-scars. 



The final history of the branches was very likely that 

 of the leaves — decay and removal complete before fossili- 

 sation. Dr. Scott suggests (i) that slender branches 

 might have been branches of limited growth, comparable 

 with the needle shoots of Pinus. The shoots belonging to 

 these scars might reasonably have been of this description. 



The interpretation of the markings described above 

 can be obtained by reference to petrified specimens. The 

 xylem of the branch — a continuation from below of the 

 stem xylem — makes its way outwards in an upwardly 

 slanting direction ; tangential sections passing transversely 

 through a branch near the cortex present a wood zone 

 broader in the upper than in the lower border, its pith 

 eccentric in situation. A strikingly similar appearance is 

 seen in the eccentric scars of Bothrodendron punctatum, 

 which Mr. Watson (2) asserted to be branch scars — an 

 opinion which has been confirmed by the discovery of 

 specimens in which the branches were still in attachment 

 (3). The funnel-like pit at the base is the cavity left by 

 the disorganised pith, which, as we know, tapered gradually 

 to its junction with the stem pith. On the other hand, 

 the sudden enlargement of the depression which opens 

 out exterior to the rim of the pit must be explained by 

 looking upon it as having been occupied not only by the 

 pith, but by both pith and xylem of the branch. That 

 this was so, and that the whole of the branch has been 

 removed from this area, is clear from the exposure of the 

 medullary ray markings on the surface of the scar. 



