OF THE FOSSIL PLANTS OF THE COAL-MEASURES. 
265 
Fig. 27. Lateral view of the base of a sporangium of a Fern allied to the Gleicheneaceee 
or Schizeaceae. Enlarged 75 diameters. 
a. Base of attachment. 
Fig. 28. Inferior surface of a similar sporangium to fig. 27. Enlarged 75 diameters. 
a. Base of attachment. 
Fig. 29. Transverse section of a similar sporangium, intersecting the annulus and filled 
with sporangia. 
Fig. 30. Transverse section of a similar sporangium made near its apex at the upper 
margin of the annulus. Enlarged 75 diameters. 
Figs. 31 & 32. Sections of two of the spores of fig. 29. Enlarged 320 diameters. 
a. Spore-wall. b. Primordial utricle. 
Gymnospermce. 
Fig. 33. Transverse section of the ligneous zone (b) and the outermost part of the 
medulla (a) of a young twig of a Dadoxylon from Coalbrookdale. Enlarged 
50 diameters. 
Fig. 34. r J transverse section of the bark of the same specimen. 
b. Outermost fibres of ligneous zone. d. Inner bark. e. Outer bark. 
Fig. 35. Vertical section of the structures seen in fig. 33. Enlarged 50 diameters. 
a. Medulla, b. Ligneous zone. V . Medullary sheath. 
Fig. 36. Vertical section of fig. 34. Enlarged 50 diameters. 
b. Outermost fibres of ligneous zone. d. Inner bark. e. Outer bark. 
Fig. 37. Barred vessels of the medullary sheath of fig. 35. Enlarged 270 diameters. 
Fig. 38. Badial section of portions of two fibres of the ligneous zone of fig. 35. 
f. Cells of a medullary ray. Enlarged 270 diameters. 
Fig. 39. Similar representation to fig. 38, but without any medullary ray. 
Fig. 40. Tangential section of parts of four fibres with four medullary rays (f) and 
interfibrous beaded lines ( g ), which are sections of the margined disks seen on 
the surfaces of figs. 38 & 39. 
Fig. 41. Vertical section of the Sternbergian pith of a Dadoxylon from near Oldham. 
Natural size. 
Fig. 42. Transverse section of the pith and ligneous zone of a large branch of a Dadoxylon 
from South Owram, near Halifax. Natural size. 
Fig. 43. Vertical section of the stem fig. 42. a. Medulla, b. Ligneous zone. 
Fig. 44. Transverse section of a small branch of a Dadoxylon from near Oldham. 
Enlarged 6 diameters. 
a. Medulla, b. Woody cylinder, d. Inner bark, y , g. Pair of bundles 
going off to leaves ? 
Fig. 45. Vertical section of fig. 44. Enlarged 6 diameters. 
a. Sternbergian pith. b. Ligneous cylinder, d. Inner bark disorganized. 
