Johnson — On Bothrodendron {Cyclostignia) kiltorkense. 513 



droid sears he figures when he assigns them to the wounds left by the falling 

 off of a branch. 



Confirmation of the general correctness of this view was supplied by 

 M. Renier (23), who found, in a split slab of rock, a stem of B. punctafum witli 

 a Ulodendroid scar on one thus exposed surface, and on the corresponding 

 surface a diehotomously dividing branch whose proximal end fitted exactly 

 into and coincided with the scar on the parent stem. Kidston seems to have 

 misinterpreted (24) inadvertently' this note of Renier as supporting the 

 explanation he and others had offered that the scars represent the points of 

 attachment of cones — an explanation amplified now by the suggestion thattlie 

 cones were not sessile but seated on a short deciduous axis. I can find nothing 

 in Renier's account to suggest that he regarded the lateral branching shoot as 

 either deciduous or fertile. He expressly states that the branch, after running 

 10 cm. in the rock, bifurcates, and that one branch so formed runs 20 cm., 

 and appears to dichotomize again. He further mentions Lepidodendron 

 selaginoides, Carr., and L. Hichil, Wats., as two species in which branches are 

 known to occur in two opposite rows. Renier regards the depth of the 

 depression as a sign of the degree of decay of the soft tissues surrounding the 

 vascular tissue represented by the umbilicus. It would appear as if the 

 severing of the branches, whether natural or artificial, was not accompanied 

 by that healing of the wound which occurs under similar conditions to-day. 

 Bothrodendron as a type would not compete under equal conditions against 

 on-coming plants with wound-healing powers. Though Renier's explanation 

 may hold good in general for B. Jcillorkeiise too, its scars are so sliallow 

 and irregularly placed that it is possible that in some of the older stems tliey 

 represent the points of attachment of stray Stigmarian appendages. Their area 

 is the same, and the umbilicus is not dissimilar to that on the Stigmarian axis. 



The slab numbered " 2 " in the series sent to M. Bronguiart is of special 

 interest. In addition to Arc/iwopferis hibernica, Forbes sp., and tlie 

 Archmo2:>teris Tac/iermnki, Stur, I have already recorded, it shows fragments of 

 the stem and groups of megaspores of B. Idltorkense, and also on this stem 

 the curiou/S creeping thread-like bodies whicli Nathorst, believing them to be 

 possibly epiphytic algse, named, from specimens he saw on the stems of 

 Bothrodendron in Bear Island, Codonopihyton epiphyticum. In the Kiltorcan 

 specimen they are generally more or less closely associated with the leaf-scars. 



Foliage. 

 Although stems of Bothrodendron kiltorkense have been found in fair 

 quantity and in all stages in Ireland and elsewhere, there is no record as yet 



' A reviewer of Renier's research, in " Palaeobotanische Zeitschrift " (I. s. 80), throws doubt on 

 Renier's conclusions owing to the inadequacy of his illustrations. 



