480 R. KIDSTON AND D. T. GWYNNE-VAUGHAN ON THE FOSSIL OSMUNDACE^. 



Plate XLIII. 



Fig. 22. An obliquely tangential section of a lamina showing the palisade tissue at a and the spongy 

 tissue at b. x 100. (Slide 2333.) 



Fig. 23. A section tangential to the lamina showing the under epidermis and stomata. x 85. 

 (Slide 2332.) 



Fig. 24. The same more highly magnified. x 150. (Slide 2332.) 



Figs. 25 and 26. Transverse sections of petioles just below the point of branching, x 27. (Slide 2323.) 



Fig. 27. Transverse section of a branching petiole with the branch trace just free, x 27. (Slide 2329.) 



Figs. 28, 29, and 30. Transverse sections of midribs of pinnae showing branching ; br., vascular supply 

 of branch, x 100. (Slides 2333 and 2334.) 



Fig. 31. Transverse section of a midrib just before giving off a branch. The protoxylem of the mother 

 racbis on the side of the branch has become mesarch. x 100. (Slide 2334.) 



Fig. 32. Transverse section of a root, x 67. (Slide 2319.) 



Fig. 33. A section approximately longitudinally tangential to the surface of a sporangium showing the 

 line of dehiscence. x 85. (Slide 2330.) 



Fig. 34. Sections of sporangia cutting the annulus along its length. x 50. (Slide 2331.)* 



Plate XLIV. 

 Osmundites Camieri, Schuster. 



Fig. 35. Part of the transverse section of the stock, l.t., l.t., leaf-traces in the cortex ; o.en., endodermis 

 on the outside of the vascular ring; in.en., endodermis on the inside of the vascular ring, x, strand shown 

 at fig. 38. x 18. The root coating is not included in the figure. x 2 '5. (Slide 2342.) 



Fig. 36. Portion of the vascular ring showing the departure of a leaf-trace. Lettering as before. The 

 internal endodermis curves outwards into the medullary rays (m.r.) and into the concavities of the xylem 

 strands. x 10. 



Fig. 37. The inner portion of a xylem strand showing the internal endodermis. x 30. 



Fig. 38. The anomalous xylem strand seen at x in fig. 35. The small strands on the inside (x, x') are 

 separate from the main mass and each surrounded by its own endodermis. x 18. 



Fig. 39. Transverse section of a root. x 30. 



Fig. 40. Portion of fig. 37 more highly magnified; tr., multiseriate tracheae. x 55. f 



* Specimens shown at figs. 1-11, 15, 21, 32 from Van-Mijensberg : those at figs. 12-14, 16-20, 22-31, 33 and 34 

 from Nordenskioldsberg. 



t We beg to acknowledge our indebtedness to the Executive Committee of the Carnegie Trust for a grant to 

 defray the cost of the plates illustrating this part of our memoir on the Fossil Osmuudacese. 



