LEPIDODENDRON. 161 



passage des faisceaux vasculaires se rendant aux feuilles. Tl est 

 a reniarquer que ces cordons foliaires prenuent naissance en face de 

 l'intervalle qui separe deux bandes ligneuses voisines ; il est 

 probable que ces deux bandes se soudent chacune a l'extrernite 

 inferieure du cordon et sont en relation conductrice avec lui." 



The specimens described by the late Dr. Renault were obtained 

 from Piracicaba, San Paulo, Brazil, where they were found in 

 association with Psaionius and Cordaitean wood. They consist of 

 two fragments showing the external or subepidermal features of 

 the stem, and a specimen in which the internal anatomy is 

 preserved. 



Guided chiefly by the structure of the stem, Renault referred 

 these specimens to a new genus, Lyeopodiopsis, on the ground that 

 the anatomy did not agree with that of any known Palaeozoic 

 member of the Lycopodiales, but presented a closer comparison 

 with the recent genus Lycopodium, from which, however, it 

 appeared to ditfer in certain important respects. The existence 

 of a well-marked pith, surrounded by a discontinuous vascular 

 ring composed of centripetally developed xyletn, made up of 

 single bundles or of bundles united internally in the form of 

 a U or a V, are features unlike those of any Club-moss. 



Professor Zeiller 1 has, however, re-examined these specimens. 

 He has pointed out that the surface showing the leaf-cushions 

 is somewhat decorticated, and does not represent the true 

 external surface, but that, if allowance be made for the change in 

 appearance due to this fact, the resemblance to a Lepidodendroid 

 stem, such as Lepidodendron selaginoides, is so marked that there 

 can be little hesitation in regarding Renault's species as a true 

 Lepidodendron He finds that the vascular cylinder in reality is 

 perfectly continuous, the apparently broad parenchymatous rays 

 between the bundles being largely composed of badly preserved 

 woody elements, the walls of which appear to be much thinner 

 than the tracheides owing to alteration which has taken place 

 during preservation. He further notices that, in the best preserved 

 specimens, there is evidence that the outer margin of the wood was 

 crenulated, as in Lepidodendron LLarcourtii, and he concludes that 



1 Zeiller (98 1 ). 



