406 Mr Wills, Notes on the genus Schizoneura, 



Notes on the genus 8chizoneura, Schimper and Mougeot. By 

 L. J. Wills, M.A., F.G.S., Fellow of King's College. (Communi- 

 cated by Mr E. A. Newell Arber.) 



[Bead 7 February 1910.] 



The genus Schizoneura though of widespread occurrence is 

 still very imperfectly known. It was founded by the eminent 

 French palaeobotanists, Schimper and Mougeot, in 1844*, on speci- 

 mens from the Upper Bunter (Voltzien-sandstein) of the Vosges 

 Mountains, which they described as S. paradoxa. Their definition 

 is somewhat loose, but its essential points are that the plant is of 

 an Equisetaceous nature, with stem divided into rather long 

 internodes; the leaves which are borne in whorls at the nodes 

 are at first united into a leaf-sheath. This later splits along 

 commissural lines into sheath-segments or into individual leaves. 



Though various species have since been described from diffe- 

 rent horizons and countries, little has been added to our knowledge 

 of the structure of this plant since 1844. Recently I have had 

 the good fortune to collect abundant material from the English 

 Lower Keuper of Bromsgrove in Worcestershire, which in some 

 ways supplements our knowledge of the species S. pai'adoxa. It 

 may be of interest to point out some details of the nature and 

 structure of Schizoneura as exemplified by this, the original, 

 species. We may then be in a more advantageous position to 

 answer the question, whether the name Schizoneura has been 

 applied to plants genetically distinct or the reverse. 



I have, however, described the Bromsgrove material in some 

 detail elsewhere f. Accordingly, I propose at present to mention 

 only the chief points of interest displayed by this plant. ^ 



There is little doubt that S. paradoxa and possibly all the 

 other species, were lovers of moist spots and, in fact, probably 

 grew actually in the water; for we find at Bromsgrove rootlets 

 and stems still apparently in their position of growth. A similar 

 mode of occurrence has been noticed by other observers|. Schizo- 

 neura paradoxa may well have reached a considerable height, for 

 stems up to about 2" in diameter and several feet in length have 

 been discovered. 



Leafy branches are the best known portions of this plant. 

 The external surface of the smaller stems was probably smooth, 

 while the larger ones may have been slightly ribbed. The leaves 

 usually number seven. So far they have never been observed 



* Schimper and Mougeot, Monograjphie des Plantes fossiles du Gres bigarre de 

 la chaine des Vosges, Leipzig, 1844. 



t Wills, L. J., Proc. Geol. Assoc. Vol. xxi. 1910, p. 271. 



J e.g. Kogers, A. W., and Seward, A. C. ; see Seward, Quart. Jourii. Geol. Soc, 

 Vol. Lxiv. 1908, p. 89. 



