292 PTERIDOPHYTA. [CH. 



the opportunity of examming more perfect material from the 

 Bunter beds of the Vosges, and proposed the new name 

 Schizoneura in place of Brongniart's term, on the grounds 

 that the specimens were in all probability portions of Equi- 

 setaceous stems, and not Monocotyledons. Our knowledge of 

 this genus is very limited, but the characteristics are on the 

 whole better defined than in the case of Phyllotheca. The 

 following diagnosis illustrates the chief features of Schizoneura. 



Hollow stems with nodes and internodes as in Equisetum\ 

 the surface of the internodes is traversed by regular ridges 

 and grooves, which are continuous and not alternate in their 

 course from one internode to the next. The leaf-sheaths are 

 large and consist of several coherent segments ; the sheaths are 

 usually split into two or more elongate ovate lobes, and each 

 lobe contains more than one vein. Fertile shoots are unknown. 



Two of the best known and most satisfactory species are 

 Schizoneura gondwanensis Feist, and S. paradooca Schimp. and 

 Moug. 



Schizoneura gondwanensis Feist. Fig. 69, A and B. 



This species is represented by numerous specimens from 

 the Lower Gondwana rocks of India ^ ; it is characterised by 

 narrow articulated stems which bear large leaf-sheaths at the 

 nodes. The sheaths may have the form of two large and 

 spreading elongate-oval lobes, each of which is traversed by 

 several veins (fig. 69, B), or the lobes may be further dissected 

 into long linear single-veined segments, as in fig. 69, A. It is 

 supposed that in the young condition each node bears a leaf- 

 sheath consisting of laterally coherent segments which, as 

 development proceeds, split into two or more lobes. Feist- 

 mantel records this species from the Talchir, Damuda and 

 Panchet divisions of the Lower Gondwana series of India; these 

 divisions are regarded as equivalent to the Perrao-Carboniferous 

 and Triassic rocks of Europe. The two specimens shown in 

 fig. 69 are from the Lower Gondwana rocks of the Raniganj 

 Coal-field, India. 



1 Feistmantel (81) p. 59, Pis. i. A— x. A. 



