﻿Manchester Memoirs, Vol. xlix. (1905), No. 17. 



XVII. The Stem and Branches of Lepidodendron 

 selaginoides. 



By F. E. Weiss, D.Sc, 



AND 



James Lomax. 



Received for publication June 6th, igoj. 



In the discussions which have taken place on the 

 relationship between the two genera Sigillaria and Lepido- 

 dendron, the two plant-remains known as Sigillaria 

 vascularis (Binney) and Lepidodendron selaginoides 

 (Sternb.) have figured very prominently. On the one 

 hand Renault, following Brongniart's lead relegated such 

 stems as those of Sigillaria vascularis, which showed a 

 ring of secondary wood [c.p.fig. 3 of Plate) to the Sigil- 

 lariae which he looked upon as allied to the Phanero- 

 gams and particularly to the Gymnosperms while the 

 Lepidodendra were according to him devoid of secondary 

 thickening and connected with the recent Lycopodiaceae. 



Binney ('62, '65, '7 2 > '75); on the other hand, in a series 

 of papers in which he described a large number of 

 specimens of Sigillaria vascularis and of Lepidodendron 

 selaginoides or Lepidodendron vasculare as he preferred to 

 call it, brought forward very considerable evidence in favour 

 of regarding the two as representing merely different stages 

 in the development of the same plant. This conclusion 

 he based upon evidence both from the external and also 

 from the internal structure of the plant. For while on the 

 one hand some specimens have a ribbed and furrowed 



June jot/i } ipoj. 



