44 T. G. HALLE, LOWER DEVONIAN VLANTS FROM RÖRAGEN IN NORWAY. 



Fig. 



Figs 

 Fig. 



» 



1. 

 2, 

 4. 

 5. 



3. 



Figs, 



6, 



7. 



Fig. 

 Figs, 



8. 

 9, 



10. 



» 



11 



—13 



Fig. 



14. 





Figs, 



15 



—17. 



Fig. 



18. 





)> 



19. 





» 



20. 





Explanation of Plates. 



(AU the figures are in natural size, if not otherwise stated.) 



Plate 1. 



Arthrostigma gracile Daws. 



Leaf-bearing stem. 



Parts of the specimen in fig. 1, sliowing leaves; X 3. 



Leaf with a single vein from the same specimen; X 5. 



Fart of another specimen; X 3. 



Leaves from the same specimen, sliowing the veins; X 5. 



Two parallel stems with dense markings of leaves. 



Stems with short, pyramidal thorns or reduced leaves. 



Surface markings from the counterpart of the specimen in fig. 10, corresponding to the markings 



at 1,, J 2 , 1 3 , resp., in fig. 10; X 6. 



Branching stem sliowing markings of thorn-like leaves and traces of the central vascular strand. 



Stems showing the central vascular strand and traces of thorns. 



Portion of the impression in fig. 17, sliowing the vascular strand with carbonaceous reinains in the 



furrows caused by the projecting ridges of the strand; X 4. 



Isolated tracheid from the same specimen; X 175. 



Impression of the central si rand in another specimen, with carbonized remains of the tracheid walls; 



X 125. 



Psilophyton princeps Daws. 



Figs. 21 — 23. Branching stems showing markings of spines. 



Fig. 24. Stem with the spines seen in profile. 



» 25. Part of the same specimen; X 3. 



Figs. 26, 27. Stems with spines seen in profile. 



» 28—31. Spines of different specimens; figs. 28, 29: X 3; figs. 30, 31: X 5. 



Plate 2. 



Psilophyton princeps Daws. 



Fig. 1. Impression of stem showing spine-markings. 



» 2. Part of the same specimen; X 2 l / 2 - 



» 3. Part of the same specimen, showing markings of spines, and sculpture; X 10. 



» 4. Part of another specimen, showing spines at the margin, and markings of spines, and sculpture, on 



the surface; X 3. 

 » 5. Part of the same specimen, showing sculpture and markings of spines; X 16. 



? Psilophyton Goldschmidtii n. sp. 

 Fig. 0. Axis with remains <>t i\\<> lateral branches. 



