OS' THE FOSSIL PLANTS OF THE COAL-MEASUEES. 
,407 
showing the tubular fibres of the prosenchymatous bands, mag- 
nified 28 diameters. 
Plate XXV. fig. 16. Tangential section of the middle cortical parenchyma of a large 
stem, giving off an exogenous branch, magnified nearly 20 
diameters. 
„ fig. 17. Double cortical bundle of vessels imbedded in the inner- 
most bark-layer with the exterior of the ligneous zone, magni- 
fied 30 diameters. 
Plate XXVI. fig. 18. Cortical bundle of vessels from fig. 1, magnified 80 diameters. 
Plate XXV. figs. 19 & 20. Cortical bundles of vessels, with peripheral exogenous 
growths, from the innermost bark-layer of fig. 1, magnified 80 
diameters. 
„ fig. 21. Cortical bundle of vessels with wedge-shaped exogenous additions 
to its exterior surface and adherent to the ligneous zone, mag- 
nified 24 diameters. 
Plate XXVI. fig. 22. The branch ( y ) of fig. 14, enlarged 60 diameters. 
„ fig. 23. Central vascular bundle, with some of the exogenous lamina: 
and medullary rays of the branch (x) of fig. 1, enlarged 100 
diameters. 
„ fig. 24. Transverse section of part of a young stem, the ligneous zone of 
which is giving off an exogenous branch. 
,, fig. 25. Transverse section of the bark of a young stem, with a double 
vascular bundle escaping through the prosenchymatous bark, 
as if to reach a petiole ; magnified 7 5 diameters. 
Plate XXVII. fig. 26. Cast of the exterior of the bark of an arborescent stem. 
,, fig. 27. Cast of the exterior of the bark of an arborescent stem. 
„ fig. 28. Cast of the exterior of the bark of an arborescent stem. 
„ fig. 29. Cast of the exterior of the bark of an arborescent stem. 
Ileterangium Grievii. 
Plate XXVIII. fig. 30. One half of the transverse section of a stem, magnified 22 
diameters. 
„ fig. 31. Portion of the medullary axis of fig. 30, magnified 70 diameters. 
Plate XXIX. fig. 32. Longitudinal section of the stem, magnified 24 diameters. 
„ fig. 33. Eadial longitudinal section of the exogenous zone of fig. 30, 
with mural medullary rays, magnified 72 diameters. 
„ fig. 33 a. Tangential section of the exogenous zone, showing the me- 
dullary rays, magnified 75 diameters. 
Plate XXVIII. fig. 34. Reticulated vessel, enlarged 200 diameters. 
Plate XXIX. fig. 35. Segment of a transverse section of the bark, magnified 24 
diameters. 
