XV] LEPIDODENDRON 141 



3. Lepidodendron saalfeldense, Solms-Laubach^ 



This Devonian species was founded on a specimen 

 3 X 2'5 cm. broad at the base, which shows the stumps of four 

 branches recalling the dichotomously branched arms of Stig- 

 maria and Pleuromeia. If these are in reality the remains of 

 Stigmaria-like horizontal branches the species affords an 

 interesting example of a Lepidodendron axis with a subter- 

 ranean rhizome of the type which has been found in several 

 Sigillarian stems. In the upper end of the axis the stele 

 consists of a solid strand of xylem which is not sufficiently 

 well preserved to show the position of the protoxylem groups. 

 A transverse section taken near the base reveals a type of 

 stele differing from that at the upper end in being composed 

 of radially disposed tracheids and in its resemblance to the 

 stele of Stigmaria. 



4s. Lepidodendron fuliginosum, Williamson. Figs. 162 — 172, 

 179, E. 



1871. Lepidodendron Harcourtii, Binney, Palseont. Soc, p. 48, PI. vii. 



fig. 6. 



1872. Halonia regvZaris, Binney, Palaeont. Soc, p. 89, PI. xv. 



1881. Lepidodendron Harcourtii, Williamson, Phil. Trans. Eoy. Soc, 

 Vol. 172, p. 288, Pis. XLix-Lii. 



1 887. Lepidodendron fuliginosum, Williamson, Proc Roy. Soc, Vol. 



XLII. p. 6. 



1891. Lepidodendron Williamsoni, Solms-Laubach, Fossil Botany, 



p. 226. 



1893. Lepidophloios fuliginosus, Kidston, Trans. Roy. Soc Edinburgh, 



Vol. xxxvni. p. 548. 



The name Lepidodendron fuliginosum was proposed by 

 Williamson in 1887 for petrified stems previously included by 

 him in Witham's species L. Harcourtii, but subsequently 

 recognised as a distinct type characterised by " the greater uni- 

 formity in the composition of the entire cortex " and by other 

 features some of which do not constitute distinctive characters. 

 The species agrees with L. Harcourtii and with L. Veltheimi- 

 anum in having a medullated stele; it is distinguished not 



1 Solms-Laubach (96) p. 18, PI. x. figs. 7—11. 



