THE FOSSIL OSMUNDACE^E. 475 



DESCRIPTION OF THE FIGURES. 

 (The figures are all from untouched photographs.) 



Plate I. 



Osmundites Kolbei. 



Fig. 1. Transverse section of the stock, x about 3. (Slide 1760.) 



Fig. 2. Portion of xylem ring showing several strands in lateral continuity. x 14. (Slide 1762.) 



Fig. 3. Longitudinal section of the trachea; of the normal xylem ring showing multiseriate pitting. 



x200. (Slide 1765.) 



Fig. 4. Longitudinal section of the stem. M.P., the mixed pith with irregularly scattered groups of 



tracheal elements ; l.t., leaf-trace. x 10. (Slide 1765.) 



Fig. 5. A lobed and swollen trachea from the mixed pith in longitudinal section. x 70. (Slide 1765.) 

 Fig. 6. The same trachea under higher magnification to show the type of pitting. x 200. (Slide 1765.) 

 Fig. 7. Longitudinal section showing a group of irregular trachea; in the mixed pith, x 70. (Slide 



1765.) 



Plate II. 



Osmundites Kolbei. 



Figs. 8 and 9. Transverse sections of leaf-traces without any decurrent islands of parenchyma on their 

 adaxial sides. x 20. (Slide 1762.) 



Fig. 10. Transverse section of a leaf-trace showing the usual method of departure with a decurrent 

 pocket of parenchyma, x 20. (Slide 1761.) 



Fig 11. Transverse section of a similar leaf-trace lower down; the pocket of parenchyma has become 

 enclosed, x 30. (Slide 1760.) 



Fig. 12. Transverse section of the xylem strand of a leaf-trace with the > protoxylem (prx.) completely 

 immersed, x 30. (Slide 1760.) 



Fig. 13. Transverse section of a leaf-trace with its xylem strand quite free from that of the stele, but 

 the leaf-gap in the xylem ring still not quite broken through, x 20. (Slide 1763.) 



Fig. 14. Longitudinal section of the stele showing the departure of a leaf-trace, l.g., leaf -gap; It. pkt., 

 the decurrent pocket; M.P., mixed pith. x 10. (Slide 1764.) 



Figs. 15 and 16. Transverse sections of leaf-traces in the inner cortex of the stem showing mesarch 

 protoxylems. x 30. (Slide 1761.) 



Figs. 17 and 18. Transverse sections of leaf-traces in the outer sclerotic cortex; there are two proto- 

 xylems which are still slightly mesarch. x 30. (Slides 1766 and 1760.) 



Plate III. 



Fig. 19. Osmundites Kolbei. Transverse section of a leaf- trace in the free petiole, scl., sclerotic ring 

 of petiole ; a, soft tissues of the leaf-trace ; b, dark layer, probably endodermis. x 8. (Slide 1767.) 



Fig. 20. Osmundites Kolbei. Transverse section of the stipular base of the petiole. Pet. I., petiolar 

 limits; scl, sclerotic ring of petiole. x 4. (Slide 1767.) 



Fig. 21. Osmundites Kolbei. Transverse section of two roots on their way out through the coating of 

 leaf-bases, x 30. (Slide 1766.) 



Fig. 22. Osmundites Schemnitzensis. Transverse section of the stock. i.C, inner cortex ; o.C, outer 

 cortex, x about 3. (Slide 1686.) 



Figs. 23 and 24. Osmundites Schemnitzensis. Transverse sections of the xylem strands of leaf-traces 

 near the stele ; each has a single endarch protoxylem. x 30. (Slide 1686.) 



Fig. 25. Osmundites Schemnitzensis. Transverse section of the free leaf-trace in the cortex of the 



