Johnson — On Bothrodendron {C'yclostigina) Iciltorkense. 517 



really large stems close to the Stigmaria specimens. At no time did I find 

 anything suggestive of the presence of Lepidodendron itself in the Kiltorcan 

 deposits; and I have concluded, though negative conclusions are dangerous, 

 from this experience, and from the detailed examination of various collec- 

 tions, that this genus does not occur there. I also look with suspicion on 

 many statements in print to the effect that a Lepidodendron occurs in a 

 Devonian deposit. 



The young branches of this genus as recorded are, in all probability, 

 Botlirodeudron. Did one not know tlie appearance presented by older stems 

 of Bothrodendron, the young stems would be certainly referred to Lepido- 

 dendron. In this way I explain many records of the occurrence of 

 Lepidodendron in Devonian beds. There can be no doubt of the presence of 

 the genus in cases where specimens show the typical Lepidodendron leaf- 

 cushions — e.g., L. Veltheimii and L. Volkmaniamim (Bear Island). It is often 

 worthy of note that in these species the leaf-cushions are small, and sugges- 

 tive of Bothrodendron connection (Donetz Becken). The Knorrias recorded 

 are probably often K. acicularis — i.e., Bothrodendron impressions, deprived of 

 the outer cortex, and showing the deeper-seated fusiform parichnos strands. 



The specimens of Bothrodendron in the Geological Museum in Jermyn 

 Street are of special interest. One specimen (Number 26238), labelled 

 " Cyclostigma kiltorliense ? Eoots ? " is very instructive. It shows the 

 connecting region between the aerial part of the stem with its leaf-scars and 

 the surface sculpturing of a true Bothrodendron and the subterranean part 

 which is in the Stigmaria condition (Plate XXXIX). Another specimen 

 (Number 26237), in the Museum Stores, labelled " Stigmaria," shows typical 

 Bothrodendron leaf-scars.' 



Tliese two specimens are clear confirmation of the conclusion I had arrived 

 at from field-work and from the examination of other specimens, that 

 Botlirodeudron bifurcates at the base of its stem once or twice to form sub- 

 aerial Stigmaria branches which have their surfaces covered with scars, 

 representative of the points of attachment of the appendages. It is interesting 

 to note in this connection that F. E. Weiss (26) has recently described a 

 Stigmaria which differs in structure somewhat from that of the common 

 Stigmaria ficoides. It is, too, regarded as probably the subterranean organ 

 of that Bothrodendron mundum whose Selaginella-like strobilus has been 

 described by Watson. It is unfortunate that tlie Irish beds contain 

 only impressions of Botlirodeudron. 



1 A drawing of this specimen was made by my son Gerald, a medical student, without assistance, 

 and the leaf-scars drawn were at once recognized by Dr. Kitchir as those of Bothrodendron. 



4g2 



