Fig. 1. 





») 2. 





» 3. 





» 4. 





» 5. 





D C. 





Figs. 7, 



8. 



KUNGL. SV. VET. AKADEMIENS HANDLINGAR. BAND 57. N:0 i. 45 



Hostimella sp. 



Fig. 7. Markeclly flattened branch-systern, probably belonging to Psilophyton Goldschmidtii. 



» 8. Slender brancb-system. 



» 9. Large repeatedly bifurcating brancb-system, ratber differeut from tbe common Hoslimella-tjTpe. 



Aphyllopteris sp. 



Fig. 10. Brancb-systems witb markedly stouter axis (racbis?) and slender brancbes. 



Figs. 11, 12. Brancbing stem-like plant-remains witb darker central strands. Tbe impressions in fig. 11 

 markedly parabel. 



Plate 3. 



Dawsonites arcuatus n. gen. et sp. 



Striated stems or branches witb lateral brancbes and sporangia (sp.). 



Part of tbe same specimen sbowing striation; in tbe upper part to tbe left a group of sporangia; X 2. 

 Brancbes and sporangia. 

 Part of tbe same specimen; X 2. 

 Top of a brancb witb sporangia. 

 Tbe same specimen; X 3. 

 Brancbes bearing sporangia; X 3. 

 Fig. 9. Sporangium, borne on a long simple stalk or brancb; possibly anotber species; X 7. 



Sporogonites exuberans Halle. 



Fig. 10. Stalked sporogonium, somewhat deformed. 



» 11. Upper part of tbe same specimen; X 2 '/ 2 - 



Figs. 12, 13. Impression of sporogonium; fig. 13, magnification of fig. 12; nearly X 2. 



» 14, 15. Counter-impressions of one sporogonium, witb carbonized remains of tbe tissue and spores; X 3. 

 » 16, 17. Counter-impressions of anotber sporogonium, partly incrusted witb ferruginous matter but witb 



unaltered spores in tbe upper part; X 3. 

 » 18 — 22. Spores in differeut magnifications, all from tbe specimen in fig. 16; fig. 18, two dense spore-masses 

 and numerous isolated spores. 

 Fig. 23. Petrified sporogonium, retaining its original sbape, witb indication of a stalk. 



» 24. Tbe same specimen; X 3. 



» 25. Tbe same specimen removed from tbe matrix and seen from tbe side; X 3. 



» 26. Longitudinal section of tbe specimen in fig. 23, sbowing tbe tbree zones of tbe capsule: wall of several 



layers of cells, sporiferous zone witb dome-sbaped upjier part, and sterile central columella; X 16. 

 » 27. Part of tbe same section, somewhat differently illuminated; X 20. 



» 28. Part of tbe left-hand side of tbe same section; sporiferous zone marked by tbe occurrence of small 



round boles af ter tbe spores fallen out during tbe process of grinding down tbe section; X 24. 

 Figs. 29, 30. Parts of tbe same section sbowing wall and sporiferous zone, witb spores; fig. 29: X 45; fig. 30: X 100. 

 » 31, 32. Parts of tbe sporiferous zone, witb spores; fig. 31: X 100; fig. 32; X 250. 



Fig. 33. P r o b 1 e m a t i c u m; X 3. 



Figs. 34, 35. P r o b 1 e m a t i c u m; fig. 35; X 3 '/ 2 . (Compare description p. 32.) 



Fig. 36. P r o b 1 e m a t i c u m. (Compare description p. 40. ) 



