,i I;, y h' 



Fig. 5 

 Asteroxylon Mackiei: a, reconstruction of vegetative regions; 

 B, t.s. stem; c, reproductive regions; d, sporangium. Asteroxylon 

 elberfeldense : e, upper portions of plant (note circinate vernation). 

 Psilophyton princeps: F, reconstruction; G, enlarged portion of 

 stem, showing enations; H, sporangia 



(a, c, d, after Kidson and Lang; e, Krausel and Weyland; f, 

 G, H, Dawson) 



