SPHENOPHYLLEAE 99 



foliatum, and were probably the roots of those species. 

 As regards the insertion of the roots, we do not know 

 any details, but they appear to have been borne on 

 the nodes. 



2. Fructifications of Sphenophyllum — 5. Dawsoni 

 Type. — We now come to the question of the fructifica- 

 tion of Sphenophyllum, our knowledge of which has 

 grown rapidly during the last few years. Our first 

 accurate information, with regard to the fructification 

 of the genus, depended on the observations of William- 

 son, who described in the greatest detail a fructification 

 which has since been proved to be that of a species of 

 Sphenophyllum, named provisionally 5. Dawsoni. We 

 are now, however, acquainted with four distinct types 

 of fructification in Sphenophyllum, on which a subdivision 

 of the genus will no doubt ultimately be based. 



We will begin with the description of the type of 

 cone investigated by Williamson, with which, as M. 

 Zeiller has shown, the fructifications of the well-known 

 species Sphenophyllum cuneifolium agree in all essential 

 respects. 1 The British specimens, which come from 

 the calcareous nodules of the Lower Coal-measures, 

 show the internal organisation in great perfection, 2 while 



1 Zeiller, "Etude sur la constitution de l'appareil fructificateur des 

 Sphenophyllum," Mini, de la Soc. gdol. de France, " Paleontologie, " Mem. 

 II, 1893. 



- Williamson first described his specimens under the name of Volk- 

 tnannia Dawsoni, using a generic name of very indefinite signification, and 

 subsequently called them Bowmanites Dawsoni. The name Bowmanites 

 (a genus founded in 1871 by Binney) is still retained for fructifications of 

 Sphenophylleae, but, as we have some evidence in this case as to the 

 vegetative structure, it is simpler to call Williamson's specimens Spheno- 

 phyllum Dawsoni — a name which may turn out to be synonymous in 

 part with S. cuneifolium. See Williamson, " On the Organisation of an 



