in] 



PSILOPHYTON 



21 



the removal of the smooth axes bearing fructifications to a separate 

 genus could hardly be justified. Hallei himself describes a new 

 species (P. Goldschmidtii) in which the axes below were spinous, 

 though without .visible macroscopic emergences in the higher 



Fig. 6. Psilophyion princeps, Dawson, from the 

 Lower Devonian of Roragen, Norway. Fer- 

 tile axes (the Dawsonites arcuaius of Halle) 

 without macroscopic emergences. After Halle 

 (1916). 



parts. We shall return to this point a little later when we shall 

 endeavour to show that in P- princeps, the axes always bear 

 emergences, though sometimes they are of microscopic size. We 

 may agree with Halle that the spiny shoots (P. ornatum of 

 Dawson) are not known in the fertile state. These shoots are 



1 Halle (1916), p. 21. 



