170 



D. H. Scott. 



sporangium. In this fossil the prothallus is often more or less per- 

 fectly^ preserved, and the archegonia can sometimes be distin- 

 guished. 



Another genus of Lycopodiaceous cones, Speiicerites {Willi Sim^on, 

 1878, 1893; Scott, 1897; B er ridge, 1905), of which two Lower 

 Coal-Measure species are known, is of interest from the characters of 

 the spores and the mode of insertion of the sporangia. The sporo- 

 phylls are sometimes arranged very regularly in alternating verticils, 



r^ 



Fig-. 10. Sjjenccrifes insignis. Somewhat diagrammatic radial section of part of the 

 cone, showing 2 sporophylls in connection with the axis. On the lower sporophyll 

 the sporangium is shown, attached at its distal end to the ventral outgrowth of 

 the sporophyll; within the sporangium some of the characteristic winged spores are 

 shown. After Miss B er ridge. 



though in other cases the ph3llotaxis appears to have been spiral. 

 The sporophyll in S. insignis consists of a narrow pedicel bearing an 

 upturned lamina with a dorsal lobe; at the base of the lamina is a 

 massive ventral outgrowth, to which the distal end of the sporangium 

 is attached by a narrow neck (Fig. 10). This mode of insertion is 

 quite different from that in Lepidosirobus, and the presence of the 

 ventral sporangiferous lobe has suggested a comparison with the 

 Sphenophyllales, though the absence of any vascular supply to the 

 ventral lobe renders the analogy somewhat remote. The spores are 



