780 THE FOSSIL OSMUND ACE^E. 



Plate V. 



Fig. 24. Osmundites skidegatensis. Portion of the vascular ring from (A) in fig. 22 more highly magnified. 

 ext. ph., external phloem ; int. ph., internal phloem ; l.g. ph., metaphloem lining the leaf-gap ; p. I., porose 

 layers ; l.g. sc, leaf-gap sclerenchyma. ( x 27.) Slide K/1251. 



Fig 25. Osmundites skidegatensis. Portion of the vascular ring from (B) in fig. 22 showing the departure 

 of a leaf-trace. It., the departed leaf-trace ; It. ph., phloem of the leaf-trace ; par., parenchyma of xylem 

 sheath ; par. 2 , parenchyma separating the phloem from the sclerenchyma of the leaf-gap. Other lettering m 

 in fig. 24. Note the pitmarks on the tracheide wall. ( x 110.) Slide K/1251. 



Fig. 26. Osmundites skidegatensis. Portion of the vascular ring from (C) in fig. 22 showing a leaf-gap 

 some little distance above the departure of a leaf-trace. Lettering as in fig. 25. ( x 105.) Slide K/1251. 



Fig. 27. Osmundites skidegatensis. The inner margin of a portion of the vascular ring showing the 

 internal phloem (int. ph. of fig. 23). Other lettering as in fig. 25. ( x 110.) Slide K/1251. 



Fig. 28. Osmundites skidegatensis. Portion of a transverse section of a leaf-trace passing through the 

 outer cortex of the stem. ab. ph., abaxial metaphloem ; ad. ph., adaxial metaphloem ; prph., protophloem 

 on abaxial side only ; par., parenchyma of xylem sheath ; par. 2 , parenchyma between phloem and sclerenchyma ; 

 scl., sclerenchyma mass in concavity of leaf-trace. ( x 84). Slide K/l_51. 



Plate VI. 

 Diagrams ; description on plate. 



